for Journals by Title or ISSN
for Articles by Keywords
help
Journal Cover Journal of Applied Ecology
  [SJR: 3.242]   [H-I: 133]   [227 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0021-8901 - ISSN (Online) 1365-2664
   Published by John Wiley and Sons Homepage  [1592 journals]
  • Prioritizing sites for ecological restoration based on ecosystem services
    • Authors: Francisco A. Comín; Beatriz Miranda, Ricardo Sorando, María R. Felipe-Lucia, Juan J. Jiménez, Enrique Navarro
      Abstract: Restoration ecology that maximizes ecosystem services (ES) requires planning at large spatial scales, which are often the most meaningful for ecosystem functioning and ES supply. As economic resources to undertake ecological restoration at large scales are scarce, prioritizing sites to enhance multiple ES supply is critical.We present the Relative Aggregated Value of Ecosystem Services (RAVES) index, to prioritize sites for ecological restoration based on the assessment of multiple ES. We tested the spatial heterogeneity of ES to identify the relevant scale to managing ES and to apply the RAVES index using a local case study. We also used the RAVES index to compare three alternative restoration scenarios to enhance ES based on the availability of socio-economic resources.The highest RAVES values were found in areas with natural vegetation and in gorges with riparian forests. The lowest values were found in crop fields, steep slopes and river stretches without riparian forest. The multiscale spatial analysis indicated that most ES showed significant heterogeneity at multiple spatial scales, especially at broad (20–30 km) and very broad (40–50 km) scales. For spatial scales smaller than 2 km, only biological control showed significant heterogeneity.The optimal socio-economic conditions to enhance ES supply were met when both private and public land, together with economic funds, were available to implement ecological restoration. As most areas with low RAVES were in private lands, even with limited funds restoration of private lands would result in a large increase in RAVES.Synthesis and applications. The Relative Aggregated Value of Ecosystem Services (RAVES) index is a practical tool to hierarchically prioritize sites for ecological restoration across large spatial scales. The RAVES index integrates both ecological information and societal values by weighting ecosystem services (ES) via a multicriteria analysis and can be used in scenario analysis to identify optimal management scenarios. We highlight the importance of analysing the spatial heterogeneity of ES to identify the most relevant scale to applying the RAVES index and to managing ES via ecological restoration.
      PubDate: 2018-01-09T19:01:03.652149-05:
      DOI: 10.1111/1365-2664.13061
       
  • Managing individual nests promotes population recovery of a top predator
    • Authors: Jennyffer Cruz; Steve K. Windels, Wayne E. Thogmartin, Shawn M. Crimmins, Leland H. Grim, Benjamin Zuckerberg
      Abstract: Threatened species are managed using diverse conservation tactics implemented at multiple scales ranging from protecting individuals, to populations, to entire species. Individual protection strives to promote recovery at the population- or species-level, although this is seldom evaluated.After decades of widespread declines, bald eagles, Haliaeetus leucocephalus, are recovering throughout their range due to legal protection and pesticide bans. However, like other raptors, their recovery remains threatened by human activities. Bald eagle nests are commonly managed using buffer zones to minimize human disturbance, but the benefits of this practice remain unquantified.Within Voyageurs National Park (VNP), Minnesota, USA, managers have monitored bald eagle populations for over 40 years, and since 1991, have protected at-risk nests from human disturbance using buffer zones (200 and 400 m radius). We aimed to (1) quantify the recovery of bald eagles in VNP (1973–2016), and (2) provide a first-ever evaluation of the individual- and population-level effects of managing individual nests. To do so, we developed Bayesian Integrated Population Models combining observations of nest occupancy and reproductive output (metrics commonly collected for raptors) to estimate nest-level probabilities of occupancy, nest success, and high productivity (producing ≥2 nestlings), as well as population-level estimates of abundance and growth.The breeding population of bald eagles at VNP increased steadily from
      PubDate: 2018-01-09T19:01:02.528935-05:
      DOI: 10.1111/1365-2664.13062
       
  • Effects of habitat quality and access management on the density of a
           recovering grizzly bear population
    • Authors: Clayton T. Lamb; Garth Mowat, Aaron Reid, Laura Smit, Michael Proctor, Bruce N. McLellan, Scott E. Nielsen, Stan Boutin
      Abstract: Human activities have dramatic effects on the distribution and abundance of wildlife. Increased road densities and human presence in wilderness areas have elevated human-caused mortality of grizzly bears and reduced bears' use. Management agencies frequently attempt to reduce human-caused mortality by managing road density and thus human access, but the effectiveness of these actions is rarely assessed.We combined systematic, DNA-based mark–recapture techniques with spatially explicit capture–recapture models to estimate population size of a threatened grizzly bear population (Kettle–Granby), following management actions to recover this population. We tested the effects of habitat and road density on grizzly bear population density. We tested both a linear and threshold-based road density metric and investigated the effect of current access management (closing roads to the public).We documented an c. 50% increase in bear density since 1997 suggesting increased landscape and species conservation from management agencies played a significant role in that increase. However, bear density was lower where road densities exceeded 0.6 km/km2 and higher where motorised vehicle access had been restricted. The highest bear densities were in areas with large tracts of few or no roads and high habitat quality. Access management bolstered bear density in small areas by 27%.Synthesis and applications. Our spatially explicit capture–recapture analysis demonstrates that population recovery is possible in a multi-use landscape when management actions target priority areas. We suggest that road density is a useful surrogate for the negative effects of human land use on grizzly bear populations, but spatial configuration of roads must still be considered. Reducing roads will increase grizzly bear density, but restricting vehicle access can also achieve this goal. We demonstrate that a policy target of reducing human access by managing road density below 0.6 km/km2, while ensuring areas of high habitat quality have no roads, is a reasonable compromise between the need for road access and population recovery goals. Targeting closures to areas of highest habitat quality would benefit grizzly bear population recovery the most.
      PubDate: 2018-01-09T02:00:00.999373-05:
      DOI: 10.1111/1365-2664.13056
       
  • Decision making for mitigating wildlife diseases: from theory to practice
           for an emerging fungal pathogen of amphibians
    • Authors: Stefano Canessa; Claudio Bozzuto, Evan H. Campbell Grant, Sam S. Cruickshank, Matthew C. Fisher, Jacob C. Koella, Stefan Lötters, An Martel, Frank Pasmans, Ben C. Scheele, Annemarieke Spitzen-van der Sluijs, Sebastian Steinfartz, Benedikt R. Schmidt
      Abstract: 1.Conservation science can be most effective in its decision-support role when seeking answers to clearly formulated questions of direct management relevance. Emerging wildlife diseases, a driver of global biodiversity loss, illustrate the challenges of performing this role: in spite of considerable research, successful disease mitigation is uncommon. Decision analysis is increasingly advocated to guide mitigation planning, but its application remains rare.2.Using an integral projection model, we explored potential mitigation actions for avoiding population declines and the ongoing spatial spread of the fungus Batrachochytrium salamandrivorans (Bsal). This fungus has recently caused severe amphibian declines in north-western Europe and currently threatens Palearctic salamander diversity.3.Available evidence suggests that a Bsal outbreak in a fire salamander (Salamandra salamandra) population will lead to its rapid extirpation. Treatments such as antifungals or probiotics would need to effectively interrupt transmission (reduce probability of infection by nearly 90%) in order to reduce the risk of host extirpation and successfully eradicate the pathogen.4.Improving the survival of infected hosts is most likely to be detrimental as it increases the potential for pathogen transmission and spread. Active removal of a large proportion of the host population has some potential to locally eradicate Bsal and interrupt its spread, depending on the presence of Bsal reservoirs and on the host's spatial dynamics, which should therefore represent research priorities.5.Synthesis and applications. Mitigation of Batrachochytrium salamandrivorans epidemics in susceptible host species is highly challenging, requiring effective interruption of transmission and radical removal of host individuals. More generally, our study illustrates the advantages of framing conservation science directly in the management decision context, rather than adapting to it a posteriori.This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-08T23:45:24.401803-05:
      DOI: 10.1111/1365-2664.13089
       
  • Environmental conditions synchronize waterbird mortality events in the
           Great Lakes
    • Authors: Karine Princé; Jennifer G. Chipault, C. LeAnn White, Benjamin Zuckerberg
      Abstract: Since the 1960s, periodic outbreaks of avian botulism type E have contributed to large-scale die-offs of thousands of waterbirds throughout the Great Lakes of the United States. In recent years, these events have become more common and widespread. Occurring during the summer and autumn months, the prevalence of these die-offs varies across years and is often associated with years of warmer lake temperatures and lower water levels. Little information exists on how environmental conditions mediate the spatial and temporal characteristics of mortality events.In 2010, a citizen science programme, Avian Monitoring for Botulism Lakeshore Events (AMBLE), was launched to enhance surveillance efforts and detect the appearance of beached waterbird carcasses associated with avian botulism type E outbreaks in northern Lake Michigan. Using these data, our goal was to quantify the within-year characteristics of mortality events for multiple species, and to test whether the synchrony of these events corresponded to fluctuations in two environmental factors suspected to be important in the spread of avian botulism: water temperature and the prevalence of green macroalgae.During two separate events of mass waterbird mortality, we found that the detection of bird carcasses was spatially synchronized at scales of c. 40 km. Notably, the extent of this spatial synchrony in avian mortality matched that of fluctuations in lake surface water temperatures and the prevalence of green macroalgae.Synthesis and applications. Our findings are suggestive of a synchronizing effect where warmer lake temperatures and the appearance of macroalgae mediate the characteristics of avian mortality. In future years, rising lake temperatures and a higher propensity of algal masses could lead to increases in the magnitude and synchronization of avian mortality due to botulism. We advocate that citizen-based monitoring efforts are critical for identifying the potential environmental conditions associated with widespread mortality events and estimating future risk to waterbird populations.
      PubDate: 2018-01-08T19:01:02.523583-05:
      DOI: 10.1111/1365-2664.13063
       
  • Linking landscape composition to predator-specific nest predation requires
           examining multiple landscape scales
    • Authors: Scott J. Chiavacci; Thomas J. Benson, Michael P. Ward
      Abstract: 1.Landscape composition around bird nests can strongly influence nest predation, a major cause of reproductive failure for many species. Understanding this relationship may improve the effectiveness of management actions aimed at reducing predation. Despite attempts to link landscape composition to nest predation, consistent patterns have proven elusive, likely because studies often examine only one landscape scale, thereby overlooking scale-specific interactions between predators and landscape features.2.To demonstrate the value of incorporating scale-dependence when connecting nest predation to landscape composition, we identified predators and analysed predator-specific patterns among land cover types at four scales (200 m, 500 m, 1 km, 2.5 km). We video monitored 468 nests of 22 shrub-nesting bird species, documented 212 predation events, and modelled relationships between landscape composition and predation by seven common predators.3.The direction and strength of predator-specific relationships varied among land cover types and scales. No single scale best predicted predation by all predators, though effects appeared to be stronger at larger scales. Two ecologically similar predators (fox snakes [Pantherophis vulpinus] and black ratsnakes [P. obsoletus]) showed contrasting relationships with different land cover types and one commonly cited predator (raccoon [Procyon lotor]) showed positive and negative links to developed cover across scales.4.Synthesis and applications. Our results illustrate that elucidating the complex relationships between different nest predator species and the landscape composition surrounding nests requires the incorporation of scale-dependence. Although such an undertaking may involve intensive nest monitoring to identify predators, it can provide managers with a more complete understanding of the linkages between predation and the landscape surrounding nests. With this knowledge, managers could employ structured decision making in an adaptive management framework to identify optimal strategies that address nest predation and allow them to confront potentially unexpected changes in predation patterns following management actions. Ultimately, by acknowledging that predator species differ in their relationships with landscape composition among different landscape scales, and incorporating this fact into future research, we can improve our ability to focus management on the habitats and scales most likely to impact predators of interest.This article is protected by copyright. All rights reserved.
      PubDate: 2018-01-05T23:25:35.124287-05:
      DOI: 10.1111/1365-2664.13090
       
  • Experimental small-scale flower patches increase species density but not
           abundance of small urban bees
    • Authors: Maria-Carolina M. Simao; Jill Matthijs, Ivette Perfecto
      Abstract: 1.Large flower plantings are often used to combat negative effects of habitat loss on pollinators, but whether these floral additions are effective at smaller scales remains unclear, particularly in urban settings.2.To test the effectiveness of small-scale floral additions on enhancing urban bee populations, as well as their impact from one year to the next, different quantities of potted sweet alyssum (Lobularia maritima) flowers were placed across sites in Ann Arbor, Michigan for two consecutive years and the resulting Halictid bee visitors were monitored.3.Overall we found the number of flowers added at the local level was significantly and positively correlated with small Halictid bee abundance and species density in an urban landscape. At smaller flower quantities dynamics were clearly linear, where incremental increases in number of flowers showed significant increases in bee abundance and species density. At larger quantities of floral additions, however, dynamics were nonlinear in that incremental increases in flower quantity had no effect on bee abundance and highly variable effects on bee species density.4.When comparing the change in small Halictid bee abundance and species density from one year to the next, we found a significant increase in bee species density in the second year of small-scale floral additions, but no significant difference in bee abundance.5.Synthesis and applications. Our results show that small flower plantings can have positive effects on small bee communities in urban systems even over a short period of time, and therefore confirm that encouraging citizens to plant flowers can be an effective conservation strategy for certain urban pollinator populations. In addition, our finding that smaller flower plantings may have higher impacts on small pollinators than larger plantings suggests resource managers interested in pollinator conservation should consider spreading multiple, smaller floral plantings across the urban landscape, rather than pooling all resources into one large flower patch.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-28T01:12:05.143796-05:
      DOI: 10.1111/1365-2664.13085
       
  • Primary rainforest amount at the landscape scale mitigates bird
           biodiversity loss and biotic homogenization
    • Authors: Urs G. Kormann; Adam S. Hadley, Teja Tscharntke, Matthew G. Betts, W. Douglas Robinson, Christoph Scherber
      Abstract: 1.Tropical conservation strategies traditionally focus on large tracts of pristine forests, but given rapid primary forest decline, understanding the role of secondary forest remnants for biodiversity maintenance is critical. Until now, the interactive effects of changes in forest amount, configuration and disturbance history (secondary vs. primary forest) on the conservation value of tropical landscapes has remained unknown, hampering the incorporation of these global change drivers into local and global conservation planning.2.We disentangled effects of landscape wide forest amount, fragment size, and forest age (old growth versus secondary forest) on abundance, α-diversity, β-diversity (biotic homogenisation) and community shifts of bird communities in human-dominated landscapes of southern Costa Rica. Utilizing two complementary methods, yielding 6900 individual detections and 223 species, we characterized bird communities in 49 forest fragments representing independent gradients in fragment size (30 ha) and forest amount (5%-80%) in the surrounding landscape (within 1000 m).3.Abundance and α-diversity of forest specialists and insectivores declined by half in small fragments, but only in landscapes with little old growth forest. Conversely, secondary forest at the landscape scale showed no such compensation effect. Similarly, a null-model approach indicated significant biotic homogenisation in small versus large fragments, but only in landscapes with little old growth forest, suggesting forest amount and configuration interactively affect β-diversity in tropical human-dominated landscapes. Finally, dramatic abundance-based community shifts relative to intact forests are largely a result of landscape-scale loss of old growth rather than changes in overall forest cover.4.Policy implications. Our study provides strong evidence that retaining old growth within tropical human modified landscapes can simultaneously curb erosion of avian forest specialist α-diversity, mitigate collapse of β-diversity (biotic homogenisation) and dampen detrimental avian community shifts. However, secondary forests play, at best, a subordinate role to mitigate these processes. To maintain tropical forest biodiversity, retaining old growth forest within landscapes should be first priority, highlighting a land-sparing approach.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-28T01:05:44.673607-05:
      DOI: 10.1111/1365-2664.13084
       
  • Effects of small-scale, shading-induced seagrass loss on blue carbon
           storage: Implications for management of degraded seagrass ecosystems
    • Authors: Stacey M. Trevathan-Tackett; Caitlin Wessel, Just Cebrián, Peter J. Ralph, Pere Masqué, Peter I. Macreadie
      Abstract: 1.Seagrass meadows are important global blue carbon sinks. Despite a 30% loss of seagrasses globally during the last century, there is limited empirical research investigating the effects of disturbance and loss of seagrass on blue carbon stocks.2.In this study, we hypothesised that seagrass loss would reduce blue carbon stocks. Using shading cloth, we simulated small-scale die-offs of two subtropical seagrass species, Halodule wrightii and Thalassia testudinum, in a dynamic northern Gulf of Mexico lagoon. The change in quantity and quality of sediment organic matter and organic carbon were compared among kill, control and bare plots before the kill treatment, shortly after the kill treatment and 11 months after the kill treatment. 210Pb age dating was performed on bare and Thalassia plots at 11 months to evaluate the impact of sediment erosion in the absence of vegetation.3.The small-scale die-off led to a 50-65% organic matter (OM) loss in the sediment in the top 8 cm of Halodule plots. Thalassia plots lost significant portions OM (50%) and organic carbon (Corg; 21-47%) in only the top 1 cm of sediment. The 210Pb profiles indicated Thalassia die-off reduced the Corg sequestration rate by 10%, in addition to a loss of ~1 years’ worth of Corg stocks (~22 g m−2). Furthermore, analyses on OM/Corg quality indicated a loss of labile OM/Corg and enhanced remineralisation by microbes.4.Synthesis and applications. This study provides empirical evidence that small-scale shading-induced seagrass die-offs can reduce seagrass carbon sequestration capacity and trigger losses of blue carbon stocks. While the losses recorded here are modest, these losses in blue carbon storage capacity are notable due to the proximity of shading structures (for example, boat docks) to seagrass habitats. Thus, policies to avoid or protect seagrass habitats from common small-scale, shading disturbances are important for optimising both carbon sequestration capacity and coastline development and management.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-26T03:05:41.1724-05:00
      DOI: 10.1111/1365-2664.13081
       
  • Prediction and attenuation of seasonal spillover of parasites between wild
           and domestic ungulates in an arid mixed-use system
    • Authors: Josephine G. Walker; Kate Evans, Hannah Rose Vineer, Jan A. van Wyk, Eric R. Morgan
      Abstract: 1.Transmission of parasites between host species affects host population dynamics, interspecific competition, and ecosystem structure and function. In areas where wild and domestic herbivores share grazing land, management of parasites in livestock may affect or be affected by sympatric wildlife due to cross-species transmission.2.We develop a novel method for simulating transmission potential based on both biotic and abiotic factors in a semi-arid system in Botswana. Optimal timing of antiparasitic treatment in livestock is then compared under a variety of alternative host scenarios, including seasonally migrating wild hosts.3.In this region, rainfall is the primary driver of seasonality of transmission, but wildlife migration leads to spatial differences in the effectiveness of treatment in domestic animals. Additionally, competent migratory wildlife hosts move parasites across the landscape.4.Simulated transmission potential matches observed patterns of clinical disease in the study area. Increased wildlife contact is correlated with a decrease in disease, suggesting that noncompetent wild hosts may attenuate transmission by removing infective parasite larvae from livestock pasture.5.Optimising the timing of treatment according to within-year rainfall patterns was considerably more effective than treating at a standard time of year. By targeting treatment in this way, efficient control can be achieved, mitigating parasite spillover from wildlife where it does occur.6.Synthesis and applications: This model of parasite transmission potential enables evidence-based management of parasite spillover between wild and domestic species in a spatio-temporally dynamic system. It can be applied in other mixed-use systems to mitigate parasite transmission under altered climate scenarios or changes in host ranges.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-26T03:05:34.502729-05:
      DOI: 10.1111/1365-2664.13083
       
  • Transient movements of a deep-water flatfish in coastal waters:
           implications of inshore-offshore connectivity for fisheries management
    • Authors: Amanda N. Barkley; Aaron T. Fisk, Kevin J. Hedges, Margaret A. Treble, Nigel E. Hussey
      Abstract: 1.Globally, small scale inshore fisheries are being recognized as highly beneficial for underdeveloped coastal communities since they directly contribute to local economies. Community coastal fisheries, however, may target species that are simultaneously harvested by large commercial vessels in adjacent offshore waters, creating uncertainty over stock units and connectivity that complicate management.2.Greenland halibut Reinhardtius hippoglossoides, a commercially important flatfish species in the Arctic, were tagged in Scott Inlet, coastal Baffin Island, Canada, with acoustic transmitters and tracked for a one-year period. Our aim was to measure fish movement and connectivity between inshore habitats, where Inuit fisheries are developing, and offshore waters, where an established commercial fishery operates. Four movement metrics were established and cluster analysis and a mixed effects model were used to define movement types and identify environmental covariates of presence/absence within the coastal environment, respectively.3.Two distinct movement patterns were characterized for Greenland halibut; the majority were transients that were no longer detected inshore by the end of November (n=47, 72%), and a smaller group of intermittently-resident fish that moved into the offshore at the same time as transient fish, but returned to the coastal environment in the winter (n=8, 12%), with the remainder being undefined. The presence of Greenland halibut in the inshore was negatively correlated with ice cover, indicating that fish moved offshore as sea ice formed.4.Synthesis and applications. Greenland halibut were previously thought to be highly resident within the coastal environment of Baffin Bay, however our data demonstrates this is not true for all areas. In Scott Inlet and adjacent coastal regions, Greenland halibut exhibit complex inshore-offshore connectivity, suggesting inshore and offshore fisheries require a shared quota. We recommend that in the face of developing global small-scale coastal fisheries, improved understanding of stock connectivity between environments is required to sustainably manage commercial fish species.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-26T03:00:28.774428-05:
      DOI: 10.1111/1365-2664.13079
       
  • Effects of increased specialization on revenue of Alaskan salmon fishers
           over four decades
    • Authors: Eric J. Ward; Sean C. Anderson, Andrew O. Shelton, Richard E. Brenner, Milo D. Adkison, Anne H. Beaudreau, Jordan T. Watson, Jennifer C. Shriver, Alan C. Haynie, Benjamin C. Williams
      Abstract: Theory and previous studies have shown that commercial fishers with a diversified catch across multiple species may experience benefits such as increased revenue and reduced variability in revenue. However, fishers can only increase the species diversity of their catch if they own fishing permits that allow multiple species to be targeted, or if they own multiple single-species permits. Individuals holding a single permit can only increase catch diversity within the confines of their permit (e.g. by fishing longer or over a broader spatial area).Using a large dataset of individual salmon fishers in Alaska, we build a Bayesian variance function regression model to understand how diversification impacts revenue and revenue variability, and how these effects have evolved since the 1970s.Applying these models to six salmon fisheries that encompass a broad geographic range and a variety of harvesting methods and species, we find that the majority of these fisheries have experienced reduced catch diversity through time and increasing benefits of specialization on mean individual revenues.One factor that has been hypothesized to reduce catch diversity in salmon fisheries is large-scale hatchery production. While our results suggest negative correlations between hatchery returns and catch diversity for some fisheries, we find little evidence for a change in variability of annual catches associated with increased hatchery production.Synthesis and applications. Despite general trends towards more specialization among commercial fishers in Alaska, and more fishers exclusively targeting salmon, we find that catching fewer species can have positive effects on revenue. With increasing specialization, it is important to understand how individuals buffer against risk, as well as any barriers that prevent diversification. In addition to being affected by environmental variability, fishers are also affected by economic factors including demand and prices offered by processors. Life-history variation in the species targeted may also play a role. Individuals participating in Alaskan fisheries with high contributions of pink salmon — which have the shortest life cycles of all Pacific salmon — also have the highest variability in year-to-year revenue.
      PubDate: 2017-12-19T19:01:02.637891-05:
      DOI: 10.1111/1365-2664.13058
       
  • Fisheries productivity under progressive coral reef degradation
    • Authors: Alice Rogers; Julia L. Blanchard, Peter J. Mumby
      Abstract: In response to multiple stressors, coral reef health has declined in recent decades, with reefs exhibiting reduced living coral and structural complexity, and a concomitant rise in the dominance of algal resources. Reef degradation alters food availability and reduces the diversity and density of refuges for prey. These changes affect predator–prey interactions and can have cascading impacts on food webs and fisheries productivity.We use a size-based ecosystem model of coral reefs that incorporates the influence of structural complexity, benthic primary production and detrital recycling to explore how predator–prey interactions and fisheries productivity respond to a gradient of reef degradation.We show that fisheries productivity overall may be robust to initial stages of reef degradation because the benefits of increased resources outweigh the costs of moderate refuge decline. However, the assemblage composition and size structure of reef fish will differ on degraded reefs, with herbivores and invertivores contributing relatively more to productivity.More significant losses of refuges associated with the erosion of structural complexity correspond to fisheries productivity losses of at least 35% compared to healthy reefs.Synthesis and applications. Our model provides fisheries managers with quantitative predictions about how fisheries productivity may change in response to the ongoing degradation of coral reefs. We predict an initial increase in productivity at intermediate reef degradation, followed by a drastic decline when structural complexity is lost. We also capture subtle changes to potential catch composition and fish size, including increases in smaller herbivorous and invertivorous fish from degraded reefs, which will undoubtedly impact fisheries value. On the one hand, our results reassure for continued productivity in the short term, but on the other, we warn against complacency. Management must change to capture any potential benefits to fisheries, and long-term sustainability still depends on the maintenance of complex coral reef habitats.
      PubDate: 2017-12-18T19:01:02.209343-05:
      DOI: 10.1111/1365-2664.13051
       
  • Livestock grazing reinforces the competitive exclusion of small-bodied
           birds by large aggressive birds
    • Authors: James Val; David J. Eldridge, Samantha K. Travers, Ian Oliver
      Abstract: 1.Grazing by domestic livestock is sometimes promoted as a management tool to benefit biodiversity. In many situations, however, it can produce negative outcomes.2.Here we examine the impacts of recent and historic livestock grazing on bird communities in the semi-arid woodlands in eastern Australia, testing the notion that grazing removes the suppressive effect of structurally complex vegetation on miners, thereby reducing the richness and abundance of small birds.3.We used time- and area-limited searches of 108 sites varying in livestock grazing history and intensity, to explore the direct and indirect effects of grazing, habitat complexity and the abundance of aggressive, large-bodied birds on smaller-bodied birds using two-way analysis of variance and structural equation modelling.4.Small birds were less abundant and had lower richness in the presence of miners. Our structural equation models indicated that recent grazing had direct suppressive effects on the abundance of miners, and both richness and abundance of all but the largest-bodied bird groups. However, higher levels of historic livestock grazing reinforced the competitive exclusion of the six small-bodied bird groups (insectivores, nectarivores, declining woodland birds, small ground foraging birds, all small birds, all non-miners) by aggressive miners via reductions in habitat complexity. Moreover, the strength of any suppressive effects on small birds or positive effects on large birds by miners increased with increasing miner abundance.5.Synthesis and applications. Our results highlight the importance of vegetation structural complexity, not only for providing habitat for woodland birds, but as barriers to the invasion and competitive dominance of miners. Our findings suggest that management actions aimed at reducing tree and shrub density to promote open woodlands are likely to have significant negative consequences for the conservation of small woodland birds.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-15T03:38:46.762919-05:
      DOI: 10.1111/1365-2664.13078
       
  • Spatial dynamics of habitat use informs reintroduction efforts in the
           presence of an invasive predator
    • Authors: Evan M Rehm; Mallory B Balsat, Nathan P Lemoine, Julie A Savidge
      Abstract: 1.Islands experience major impacts from introduced species, especially nocturnal predators. The brown tree snake (Boiga irregularis) extirpated almost the entire native avifauna on Guam after introduction. Reintroductions from neighbouring islands can restore bird communities but will take place in heavily managed units where snake populations can be controlled. Yet reintroductions often proceed without relevant biological information such as habitat and space use when nocturnal predators are present. To guide efforts, we studied the avian frugivore community's diurnal and nocturnal habitat and space use on the island of Saipan, where the snake is absent.2.Using radio telemetry and a Bayesian framework, we compared data typically accessible to resource managers (diurnal home range [DHR] and habitat selection), which often form the basis of reintroduction plans. We contrasted this with data on nocturnal habitat use that is often not available but relevant when nocturnal predation threat is high.3.DHR size varied within and among species with Micronesian Starlings (Aplonis opaca) having DHRs at least 45 ha larger than other species. For all species, night roost locations were generally spatially clustered within a DHR and covered a smaller spatial extent. Two species had higher probabilities of roosting outside DHR boundaries but, when outside, roosts were often within 200 m of the DHR boundary. All species selected forested habitats during day and night, with some species choosing native forest over non-native habitat.4.Synthesis and applications. If individuals roosted randomly throughout diurnal home ranges (DHRs), landscape-level suppression of the brown tree snake on Guam might be the only viable option for reintroductions. However, we found all species showed clustered roosting and high site fidelity. If site fidelity is common, then individuals that roost within fenced areas where snake populations are severely reduced will experience high survival even if DHRs extend into the surrounding unprotected matrix. There was large overlap in habitat selection during day and night, indicating managed areas should be composed of native forest with non-native forests of secondary importance. In systems with nocturnal predators, understanding variability in diurnal and nocturnal habitat use could lead to better informed management decisions.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-14T02:20:40.669014-05:
      DOI: 10.1111/1365-2664.13076
       
  • A tale of two studies: detection and attribution of the impacts of
           invasive plants in observational surveys
    • Authors: Kevin E. Mueller; Alexandra G. Lodge, Alexander M. Roth, Timothy J.S. Whitfeld, Sarah E. Hobbie, Peter B. Reich
      Abstract: 1.Short-term experiments cannot characterize how long-lived, invasive shrubs influence ecological properties that can be slow to change, including native diversity and soil fertility. Observational studies are thus necessary, but often suffer from methodological issues.2.To highlight ways of improving the design and interpretation of observational studies that assess the impacts of invasive plants, we compare two studies of nutrient cycling and earthworms along two separate gradients of invasive shrub abundance. By considering the divergent sampling strategies and statistical analyses of these two studies, and interpreting their contradictory results in the context of other studies, we also aim to better describe the impacts of the focal invader, Rhamnus cathartica.3.In a new study of a single site in Minnesota, we observed positive correlations between buckthorn abundance and soil pH, soil nutrient pools, nutrient fluxes through leaf litterfall, earthworm abundance, and root biomass. Multiple regression models showed these relationships persisted after accounting for variability in soil texture and tree species composition. For a separate, more expansive study in Illinois, other authors reported little to no correlation between buckthorn abundance and 10 soil properties, including earthworm abundance, pH, and nutrient concentrations. However, like many other studies, their regression models only assessed predictors related to invader abundance. R2 values for models of ecosystem properties ranged from 0-0.79 (adjusted-R2) for our study in Minnesota and from
      PubDate: 2017-12-13T01:34:08.716169-05:
      DOI: 10.1111/1365-2664.13075
       
  • Improving private land conservation with outcome-based biodiversity
           payments
    • Authors: Jane A. McDonald; Kate Helmstedt, Michael Bode, Shaun Coutts, Eve McDonald-Madden, Hugh P. Possingham
      Abstract: 1.Payments to private landholders for providing biodiversity land can improve conservation outside protected areas. Input-based payments are widely used despite evidence they are often ineffective at improving biodiversity outcomes. Meanwhile little has been done to assess how to use outcome-based payments to maximize biodiversity, despite growing academic interest. We compare different outcome-based allocation methods to assess which returns the greatest benefits for biodiversity.2.We predicted the likely landholder actions in response to outcome-based payments. We incorporated strategic interactions between landholders under four different funding allocation methods: the commonly applied “set-price” allocation method; capacity-based payments; proportional payment; and payment for change. We compared biodiversity outcomes (percentage change in abundance of a species of conservation interest), return on investment and cost-effectiveness of each method.3.The set-price allocation method, despite its common usage, is the least cost-effective method that we test. Regardless of cost, it only results in better biodiversity outcomes than other methods under a very narrow range of conditions (high initial target species abundance and low profitability).4.The profitability of the property, and to a lesser degree initial population size, will influence which allocation method will perform best. Most perform well when the initial population of the species of conservation interest is very small and profitability negligible. Only one method – based on change in population – performs well across all scenarios. This method outperforms the others particularly when the property has a higher profitability and low initial numbers of animals.5.Policy implications. Pursuing conservation on private land using outcome-based payments for biodiversity can result in varied levels of success depending on the allocation methods used to support payment decisions. Allocation method choice should be based on a transparent analysis that incorporates both the dynamics of the ecological system and interactions between individual landholders. This analysis can guide adoption of funding allocation methods that greatly increase biodiversity outcomes.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-11T01:36:11.947601-05:
      DOI: 10.1111/1365-2664.13071
       
  • Applicability and limitations of sensitivity analyses for wildlife
           management
    • Authors: Oliver Manlik; Robert C. Lacy, William B. Sherwin
      Abstract: Sensitivity analyses that assess the impact of changing vital rates on population growth have been widely used to guide conservation. If implemented with caution, they can provide guidance as to which management actions will optimize conservation outcomes.In this review, we first focus on the commonly used proportional sensitivity and elasticity analyses that change each vital rate by equal proportions, to assess their importance for wildlife management. These types of analyses also feature potential pitfalls and limitations, including (1) Each vital rate is usually on a different scale. Without appropriate scaling this can result in a flawed evaluation of the importance of vital rates. (2) Vital rates rarely change at equal proportions in nature. This can bring about misguided management recommendations on the basis of vital rate changes that are unrealistic. (3) Proportional sensitivity analyses often do not reflect the feasibility and effectiveness of altering particular demographic parameters. Consequently, relying solely on proportional sensitivities or elasticities can lead to flawed evaluation of the importance of vital rates and thus prioritization of management options that are unrealistic or ineffective.We outline alternative approaches, which involve assessing the impact of threats, the relative demography of stable and declining populations, the effect of observable variation of vital rates on population viability, and the potential effects of feasible management scenarios.Synthesis and applications. Sensitivity analyses are useful tools to guide wildlife management. If implemented and interpreted with care, sensitivity analyses can identify key demographic parameters and threats to population viability. However, their usefulness is limited, when applied without careful evaluation as to whether the perturbations evaluated are realistic, feasible and meet the need of wildlife managers. We caution against the over-reliance on proportional sensitivity and elasticity analyses and point to alternative approaches, including life-stage simulation analysis, vital rate sensitivity analysis or manual perturbations.
      PubDate: 2017-12-10T19:01:02.142714-05:
      DOI: 10.1111/1365-2664.13044
       
  • Contrasting impacts of land use change on phylogenetic and functional
           diversity of tropical forest birds
    • Authors: Philip M. Chapman; Joseph A. Tobias, David P. Edwards, Richard G. Davies
      Abstract: 1.Biodiversity conservation strategies increasingly target maintaining evolutionary history and the resilience of ecosystem function, not just species richness (SR). This has led to the emergence of two metrics commonly proposed as tools for decision making: phylogenetic diversity (PD) and functional diversity (FD). Yet the extent to which they are interchangeable remains poorly understood.2.We explore shifts in and relationships between FD and PD of bird communities across a disturbance gradient in Borneo, from old-growth tropical forest to oil palm plantation.3.We show a marked decline in PD, and an increase in phylogenetic mean nearest taxon distance (MNTD) from forest to oil palm, in line with declining SR across the gradient. However, phylogenetic mean pairwise distance (MPD) is constrained by forest logging more than by conversion to oil palm, taking account of SR.4.The decline in FD across the gradient is less severe than in PD, with all metrics indicating relatively high trait diversity in oil palm despite low SR, although functional redundancy is much reduced. Accounting for SR, levels of functional over- or under-dispersion of bird communities are strongly coupled to habitat disturbance level rather than to any equivalent phylogenetic metric.5.Policy Implications. We suggest that while phylogenetic diversity (PD) is an improvement on species richness as a proxy for functional diversity (FD), conservation decisions based on PD alone cannot reliably safeguard maximal FD. Thus, PD and FD are related but still complementary. Priority setting exercises should use these metrics in combination to identify conservation targets.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-07T22:42:08.022378-05:
      DOI: 10.1111/1365-2664.13073
       
  • Oak habitat recovery on California's largest islands: Scenarios for the
           role of corvid seed dispersal
    • Authors: Mario B. Pesendorfer; Christopher M. Baker, Martin Stringer, Eve McDonald-Madden, Michael Bode, A. Kathryn McEachern, Scott A. Morrison, T. Scott Sillett
      Abstract: Seed dispersal by birds is central to the passive restoration of many tree communities. Reintroduction of extinct seed dispersers can therefore restore degraded forests and woodlands. To test this, we constructed a spatially explicit simulation model, parameterized with field data, to consider the effect of different seed dispersal scenarios on the extent of oak populations. We applied the model to two islands in California's Channel Islands National Park (USA), one of which has lost a key seed disperser.We used an ensemble modelling approach to simulate island scrub oak (Quercus pacifica) demography. The model was developed and trained to recreate known population changes over a 20-year period on 250-km2 Santa Cruz Island, and incorporated acorn dispersal by island scrub-jays (Aphelocoma insularis), deer mice (Peromyscus maniculatus) and gravity, as well as seed predation. We applied the trained model to 215-km2 Santa Rosa Island to examine how reintroducing island scrub-jays would affect the rate and pattern of oak population expansion. Oak habitat on Santa Rosa Island has been greatly reduced from its historical extent due to past grazing by introduced ungulates, the last of which were removed by 2011.Our simulation model predicts that a seed dispersal scenario including island scrub-jays would increase the extent of the island scrub oak population on Santa Rosa Island by 281% over 100 years, and by 544% over 200 years. Scenarios without jays would result in little expansion. Simulated long-distance seed dispersal by jays also facilitates establishment of discontinuous patches of oaks, and increases their elevational distribution.Synthesis and applications. Scenario planning provides powerful decision support for conservation managers. We used ensemble modelling of plant demographic and seed dispersal processes to investigate whether the reintroduction of seed dispersers could provide cost-effective means of achieving broader ecosystem restoration goals on California's second-largest island. The simulation model, extensively parameterized with field data, suggests that re-establishing the mutualism with seed-hoarding jays would accelerate the expansion of island scrub oak, which could benefit myriad species of conservation concern.
      PubDate: 2017-12-05T19:01:02.279824-05:
      DOI: 10.1111/1365-2664.13041
       
  • Nesting sites of giant honey bees modulated by landscape patterns
    • Authors: Charlotte Pavageau; Cédric Gaucherel, Claude Garcia, Jaboury Ghazoul
      Abstract: 1.The composition of agro-ecological landscapes is thought to have important implications for the production of major crops through its effects on pollinator abundance and behaviour.2.We explored the roles of land cover and land cover heterogeneity on bee nest distribution for the giant honeybee Apis dorsata, a key species for coffee pollination, in a complex agroforest landscape. We emphasized scaling and non-uniform effects by combining two different approaches of spatial analysis, the point-pattern analysis and surface-pattern analysis.3.We found non-exclusive, positive effects of agroforests, forest fragments and land cover heterogeneity on the presence and number of nests. The distribution of nests responded to habitat heterogeneity at small scale (
      PubDate: 2017-12-05T02:35:41.03778-05:0
      DOI: 10.1111/1365-2664.13069
       
  • Experimentally simulating warmer and wetter climate additively improves
           rangeland quality on the Tibetan Plateau
    • Authors: Wei Xu; Mengyao Zhu, Zhenhua Zhang, Zhiyuan Ma, Huiying Liu, Litong Chen, Guangmin Cao, Xinquan Zhao, Bernhard Schmid, Jin-Sheng He
      Abstract: 1.The vast expanses of rangeland on the Tibetan Plateau, which support the livelihood of ~9.8 million local inhabitants, have experienced rapid climate warming over the past 50 years. At the same time, precipitation has increased in large parts of the Plateau but decreased in other parts, particularly in the northwest. These trends are predicted to continue into the future. However, their potential effects on rangeland quality remain unclear.2.We conducted a two-factor field experiment in which we manipulated temperature (control or warming by 1.5–1.8 °C) and precipitation (control or 50% reduction or increase in rainfall) in an alpine grassland on the north-eastern Tibetan Plateau, starting in 2011. From 2014–2016, we measured forage production and community composition, and in 2015 forage quality (crude protein, cell soluble contents, hemicellulose, cellulose, lignin and digestibility) represented by seven abundant species.3.Overall, warming did not change total forage production at plant community level, but increased legume production and decreased non-legume forb production. Increased and reduced precipitation enhanced and decreased forage production by 18.2% and 12.9%, respectively. Increased precipitation in particular increased grass and sedge production, but not legume production.4.Forage quality showed species-specific responses to the simulated climate changes. At community level, warming and reduced precipitation improved forage quality, which was mainly caused by a shift in community composition towards more legumes, rather than the direct effects of simulated climate changes. Meanwhile, increased precipitation did not reduce forage quality, despite the precipitation-induced increase in forage production.5.Integrating forage production and quality into nutrient production as a measure of rangeland quality, we found that warming and increased precipitation additively improved rangeland quality, while reduced precipitation decreased it.6.Synthesis and applications. Rangeland quality, an important ecosystem provisioning service, will benefit from a warmer climate on the Tibetan Plateau in the regions with a predicted increase in precipitation, but not in those regions where precipitation might be reduced in the future. We suggest management strategies, including reseeding native legumes, establishing sustainable pastures and assisting the exchange of harvested forage, to cope with the challenges posed by these different climate change scenarios.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-05T02:30:46.988899-05:
      DOI: 10.1111/1365-2664.13066
       
  • Local biodiversity erosion in South Brazilian grasslands under moderate
           levels of landscape habitat loss
    • Authors: Ingmar R. Staude; Eduardo Vélez-Martin, Bianca O. Andrade, Luciana Regina Podgaiski, Ilsi I. Boldrini, Milton Mendonça, Valério D. Pillar, Gerhard E. Overbeck
      Abstract: 1.Habitat loss is one of the greatest threats to biodiversity, exerting negative effects on the ecological viability of natural vegetation remnants. The South Brazilian grasslands belong to one of the largest temperate grassland regions in the world, but have lost 50% of their natural extent in the past 35 years. To date, there is no empirical evidence for the effects of habitat loss on these grasslands’ biological diversity, undermining their conservation.2.Using data from a large-scale biodiversity survey, we asked if local plant communities respond to levels of habitat loss representative of the entire region (≤50%). Vegetation in grassland remnants was sampled in 24 landscapes at three localities each, using 9 plots per locality. To investigate whether species losses were a consequence of stochastic or nonrandom local extinctions and whether plant communities became more homogenized, we evaluated species richness, beta-diversity components (spatial turnover and nestedness), and phylogenetic diversity, in respect to landscape change. In part of the landscapes, arthropods were sampled to investigate if loss of plant diversity had a cascading effect on other trophic levels. We evaluated generic richness of ants, an omnivore group with high levels of plant associations, in respect to a plant community's phylogenetic diversity.3.Local plant communities in landscapes with less grassland cover had fewer species, less spatial turnover, increased nestedness and lower phylogenetic diversity. Our results suggest that the observed species loss can be linked to taxonomic homogenization and is nonrandom, decreasing evolutionary diversity within the community. Furthermore, ant richness declined by 50% in plant communities with the lowest phylogenetic diversity, suggesting that effects of habitat loss propagate to higher trophic levels.4.Policy implications. We conclude that the biological diversity of South Brazilian grasslands, at the producer and consumer level, is at risk under the current rate of land use conversion, even at habitat losses below 50%. To avoid substantial biodiversity loss, conservation and more restrictive policies for conversion of native grasslands to different land uses in South Brazil are urgent.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-05T02:30:38.290024-05:
      DOI: 10.1111/1365-2664.13067
       
  • Functional traits associated with the establishment of introduced
           Phytophthora spp. in Swedish forests
    • Authors: Miguel A. Redondo; Johanna Boberg, Jan Stenlid, Jonàs Oliva
      Abstract: 1.Invasive forest pathogens of the genus Phytophthora are threatening ecosystems globally. Phytophthora species are mainly introduced by humans importing infected nursery stock. However, due to the presence of environmental filters, not all introduced Phytophthoras manage to establish and spread. Phytophthoras’ ability to overcome these filters may be linked to functional traits. In northern Europe, the increasing number of reports calls for a better understanding of the invasion process to prevent future outbreaks.2.We hypothesized that the incidence of invasive Phytophthoras in urban locations would be higher than in remote forests, that there would be a decrease of species richness along the invasion process because of environmental filtering, and that there would be a functional shift among Phytophthora communities between stages of invasion. We compared the species composition of 96 plots from 16 rivers running through areas that constitute a gradient of human influence. We also compared the species composition and functional diversity of Phytophthora communities in 8 nurseries and 14 forests, including anthropogenic and natural forests. Phytophthoras were isolated from river water, soil, and/or plant tissue. Cultures were identified based on the Internal Transcribed Spacer (ITS) region.3.Three Phytophthoras were detected in all environments (P. cactorum, P. plurivora, and P. cambivora). The incidence of these species was higher in urban locations than in remote forests, suggesting that human activities act as a driver of invasion. Most of the Phytophthoras detected in forests were detected in nurseries. The Phytophthora community in nurseries was richer and more diverse than in forests, pointing to environmental filtering affecting the establishment. Phytophthora communities in nurseries and forests differed in their functional divergence. Traits associated with establishment were the ability to form asexual survival structures and lower cardinal temperatures for growth.4.Synthesis and applications. Our findings support the view that human activities act as drivers of Phytophthora invasions, and suggest that Phytophthoras able to form asexual structures are more likely to establish in northern Europe. The results increase the capacity to predict the establishment of Phytophthora species in Sweden and expand our understanding of the invasion process of forest pathogens.This article is protected by copyright. All rights reserved.
      PubDate: 2017-12-05T02:30:26.116923-05:
      DOI: 10.1111/1365-2664.13068
       
  • Identifying Critical Life Stage Transitions for Biological Control of
           Long-lived Perennial Vincetoxicum Species
    • Authors: Lindsey R. Milbrath; Adam S. Davis, Jeromy Biazzo
      Abstract: 1.Demographic matrix modelling of invasive plant populations can be a powerful tool to identify life stage transitions for targeted disruption, in order to cause population decline. This approach can provide quantitative estimates of reductions in select vital rates needed to reduce population growth rate (λ) below 1 and can inform the pre-release selection of effective biological control agents, as in the case of two invasive Vincetoxicum species in North America.2.We parameterized a five life stage matrix model using vital rate data from six populations (field and forest) of V. nigrum and V. rossicum. Elasticity analyses were used to identify life stage transitions and associated vital rates for perturbation through the incorporation of per capita impact data of candidate agents.3.Several survival, growth and fecundity-related transitions were identified that were mostly similar across species, habitats and locations, although two populations showed unique population dynamics. Reductions in associated vital rates needed to prevent population growth varied greatly among populations.4.Defoliation damage and predispersal seed predation can be effective against slower growing forest and field populations of Vincetoxicum species. A fly and bivoltine moth are recommended as priority agents. However, biological control with these same agents will be ineffective against other field populations as well as some forest populations if the intensity of damage is not severe.5.Synthesis and applications. Control of long-lived perennial plants, such as species of Vincetoxicum, is projected to occur through disruption of some individual vital rates of survival, growth or fecundity if population increase is low to moderate (λ
      PubDate: 2017-12-05T02:25:23.373804-05:
      DOI: 10.1111/1365-2664.13065
       
  • Identifying potential gaps in pesticide risk assessment: Terrestrial life
           stages of freshwater insects
    • Authors: Jes Jessen Rasmussen; Peter Wiberg-Larsen, Annette Baattrup-Pedersen, Marianne Bruus, Beate Strandberg, Peter Borgen Soerensen, Morten Tune Strandberg
      Abstract: Insecticides are important drivers of biodiversity loss and ecological impairment in freshwater ecosystems. Freshwater insects may be exposed to insecticides via water during larval/nymph stages and via air, habitats, and food during adult stages in the terrestrial environment.The aquatic risk assessment (RA) of pesticides does not consider terrestrial life stages, and a literature review revealed that pesticide ecotoxicity data for adult freshwater insects are very scarce and outdated. Consequently, it is not possible to assess how adult freshwater insects may be protected through RA programs for terrestrial non-target organisms.We give guidance to generating and using of such ecotoxicity data focusing on species selection, test design and type of ecotoxicity information.Policy implications. This commentary considers how terrestrial stages of aquatic insects are protected by pesticide risk assessment (RA) and highlights the necessity of performing holistic risk assessment, focusing on organisms and populations as supplement to current subdivisions in element-based compartments (e.g. aquatic and terrestrial ecosystems).
      PubDate: 2017-12-04T23:16:03.361189-05:
      DOI: 10.1111/1365-2664.13048
       
  • Shifts in plant functional strategies over the course of wheat
           domestication
    • Authors: Agathe Roucou; Cyrille Violle, Florian Fort, Pierre Roumet, Martin Ecarnot, Denis Vile
      Abstract: Human selection, changes in environmental conditions and management practices drove the phenotypic trajectory of crops during domestication. The characterization of the crop domestication syndrome lies mostly on reproductive characters. However, biophysical and ecophysiological constraints during vegetative growth are also at play and can strongly impact crop phenotypes. It has been argued that a broadened examination of crop phenotypes through a functional trait-based lens should improve our understanding of the domestication syndrome.We used a collection of 39 genotypes representative of key steps during tetraploid wheat domestication and grew them in a common garden experiment. We quantified the vegetative phenotype of each genotype through the measurements of 13 functional traits related to root, leaf and whole-plant dimensions.In modern cultivars, compared to ancestral forms, leaf longevity was shorter, while net photosynthetic rate, leaf production rate and nitrogen content were higher. Modern cultivars had a shallower root system and exhibited a larger proportion of fine roots, preferring to invest biomass above-rather than below-ground. We found ancestral forms to be integrated phenotypes characterized by coordination between above- and below-ground functioning. Conversely, in modern forms, human selection appeared to have broken this coordination and to have generated a new type of network of trait covariations.Synthesis and applications. The examination of leaf, root and whole-plant traits of wheat accessions indicated a strong shift in plant functional strategies over the course of domestication. Elite genotypes tended to better optimize resource-use acquisition strategies than ancestral ones. The characterization of the crop phenotype based on vegetative traits thus suggests a much more complete domestication syndrome. Our findings highlight the benefits of using a functional trait-based characterization of crop phenotypes to document the extent of domestication syndrome and to further advance the agroecological management of cereals.
      PubDate: 2017-12-02T02:35:27.591696-05:
      DOI: 10.1111/1365-2664.13029
       
  • Local-scale attributes determine the suitability of woodland creation
           sites for Diptera
    • Authors: Lauren Fuller; Elisa Fuentes-Montemayor, Kevin Watts, Nicholas A. Macgregor, Katja Bitenc, Kirsty J. Park
      Abstract: New native woodlands are typically created in a small and isolated configuration, potentially reducing their value as a resource for biodiversity. The use of ecological networks for habitat restoration and creation could be beneficial for woodland biodiversity. This approach is conceptualised as local- and landscape-scale conservation actions designed to increase the area, quality, amount and connectivity of habitat types. However, there is limited evidence about the value of secondary woodlands and the relative or combined effects of network variables for woodland insects.Seventy-eight woodland sites created in the last 160 years across England and Scotland were sampled for hoverflies (Diptera: Syrphidae) and craneflies (Diptera: Tipuloidea), using two Malaise net traps placed in the centre of each woodland. The diversity of insects supported by created woodland patches was analysed using measures of dissimilarity, and the relative direct and indirect effects of ecological network variables on their abundance and species richness were assessed using structural equation models.We found 27% of British woodland hoverfly species and 43% of British woodland cranefly species in the study sites, indicating that woodland insects are colonising created native woodlands, despite their fragmented nature. However, these species communities were highly variable across woodland patches.Landscape-scale variables had no effect on woodland-associated hoverflies or craneflies relative to local-scale variables. Local-scale variables relating to habitat quality (i.e. structural heterogeneity of trees and understorey cover) had the strongest influence on abundance and species richness.Synthesis and applications. To benefit woodland-associated Diptera, woodland creation and restoration should maintain a focus on habitat quality. This should include active management to facilitate a diverse tree and understorey vegetation structure. Many woodlands in the UK are privately owned, and landowners should be encouraged to plant and actively manage their woodlands to increase structural heterogeneity and resources for woodland insects.
      PubDate: 2017-12-01T23:20:36.57219-05:0
      DOI: 10.1111/1365-2664.13035
       
  • Integrating decision triggers into conservation management practice
    • Authors: Kelly Bie; Prue F. E. Addison, Carly N. Cook
      Abstract: Decision triggers show great potential for facilitating timely management action, promoting evidence-based management and preventing undesirable changes to the status of species, ecosystems and threats. Integration of decision triggers into day-to-day management practice has been slow, constrained by insufficient resources and limited in-house expertise. Arguably, the greatest impediment is the lack of an overarching process with robust and accessible methods for developing and implementing decision triggers in a manner that fits within an organization's established processes and skill sets.We identify the steps necessary for setting decision triggers and highlight how these steps align with commonly used conservation planning and management frameworks, for ease of adoption.We emphasize that decision triggers do not require a known ecological threshold, and can be applied to data-rich and data-poor contexts, with single or multiple management objectives.Synthesis and applications. This work highlights the necessary steps involved, and importantly, the suite of methods that can be used to set decision triggers, with the aim of supporting practitioners in the development of robust and defensible decision triggers.
      PubDate: 2017-11-30T05:36:29.760933-05:
      DOI: 10.1111/1365-2664.13042
       
  • Deployment of organic farming at a landscape scale maintains low pest
           infestation and high crop productivity levels in vineyards
    • Authors: Lucile Muneret; Denis Thiéry, Benjamin Joubard, Adrien Rusch
      Abstract: Organic farming is a promising way to reduce pesticide use but increasing the area under organic farming at the landscape scale could increase pest infestations and reduce crop productivity. Examining the effects of organic farming at multiple spatial scales and in different landscape contexts on pest communities and crop productivity is a major step in the ecological intensification of agricultural systems.We quantified the infestation levels of two pathogens and five arthropod pests, the intensity of pesticide use and crop productivity in 42 vineyards. Using a multi-scale hierarchical design, we unravelled the relative effects of organic farming at both field and landscape scales from the effects of semi-natural habitats in the landscape.At the field scale, pest communities did not differ between organic and conventional farming systems. At the landscape scale, increasing the area under organic farming did not increase pest infestation levels.Three out of seven pest taxa were affected both by local farming systems and the proportion of semi-natural habitats in the landscape. Our findings revealed that the proportion of semi-natural habitats reduced pest infestation for two out of seven pest taxa.Organic vineyards had much lower treatment intensities, very similar levels of pest control and equal crop productivity levels.Synthesis and Applications. Our results clearly indicate that policies promoting the development of organic farming in conventional vineyard landscapes will not lead to greater pest and disease infestations but will reduce the pesticide treatment intensity and maintain crop productivity. Moreover, the interactions between semi-natural habitats in landscape and local farming practices suggest that the deployment of organic farming should be adapted to landscape contexts.
      PubDate: 2017-11-29T05:42:10.284256-05:
      DOI: 10.1111/1365-2664.13034
       
  • Illuminating prey selection in an insectivorous bat community exposed to
           artificial light at night
    • Authors: Zachary M. Cravens; Veronica A. Brown, Timothy J. Divoll, Justin G. Boyles
      Abstract: Light pollution has been increasing around the globe and threatens to disturb natural rhythms of wildlife species. Artificial light impacts the behaviour of insectivorous bats in numerous ways, including foraging behaviour, which may in turn lead to altered prey selection.In a manipulative field experiment, we collected faecal samples from six species of insectivorous bats in naturally dark and artificially lit conditions, and identified prey items using molecular methods to investigate effects of light pollution on prey selection.Proportional differences in identified prey were not consistent and appeared to be species specific. Red bats, little brown bats and grey bats exhibited expected increases in moths at lit sites. Beetle-specialist big brown bats had a sizeable increase in beetle consumption around lights, while tri-coloured bats and evening bats showed little change in moth consumption between experimental conditions. Dietary overlap was high between experimental conditions within each species, and dietary breadth only changed significantly between experimental conditions in one species, the little brown bat.Policy implications. Our results, building on others, demonstrate that bat–insect interactions may be more nuanced than the common assertion that moth consumption increases around lights. They highlight the need for a greater mechanistic understanding of bat–light interactions to predict which species will be most affected by light pollution. Given differences in bat and insect communities, we advocate biologists, land stewards and civil planners work collaboratively to determine lighting solutions that minimize changes in foraging behaviour of species in the local bat community. Such efforts may allow stakeholders to more effectively craft management strategies to minimize unnatural shifts in prey selection caused by artificial lights.
      PubDate: 2017-11-29T05:41:43.748655-05:
      DOI: 10.1111/1365-2664.13036
       
  • Size and spacing rules can balance conservation and fishery management
           objectives for marine protected areas
    • Authors: Rachel Fovargue; Michael Bode, Paul R. Armsworth
      Abstract: Marine protected areas (MPAs) are increasingly integrated into fishery management for coastal systems. Size and spacing rules (SSRs) have been proposed as simple MPA design guidelines, especially in regions where population connectivity data are limited.We assessed whether SSRs allow managers to design effective MPA networks under spatiotemporally varying dispersal patterns using a spatially realistic population model parameterized for a commercially-exploited fish species on the Great Barrier Reef.SSRs are used to design MPA networks, and population simulations are used to measure the mean and variance of the resulting population size and fishery catch.We show that SSR performance is contingent on the extent of the MPA network, and whether species’ connectivity data can be used to target areas for protection. For example, in the absence of connectivity data, a “many small” MPAs rule provides the least variable management outcome.Synthesis and applications. We demonstrate that the performance and usefulness of size and spacing rules (SSRs) as guidelines for marine protected areas (MPAs) depend on the level of knowledge about larval dispersal, as well as the level of current exploitation in the fishery. These context-dependent results offer particularly relevant guidance to future MPA design projects in regions with limited connectivity data.
      PubDate: 2017-11-28T23:31:05.715833-05:
      DOI: 10.1111/1365-2664.13043
       
  • Development of an aggressive bark beetle on novel hosts: Implications for
           outbreaks in an invaded range
    • Authors: Derek W. Rosenberger; Robert C. Venette, Brian H. Aukema
      Abstract: 1.Some subcortical insects have devastating effects on native tree communities in new ranges, despite benign interactions with their historical hosts. Examples of how insects, aggressive in their native habitat might respond in novel host environs are less common. One aggressive tree-killing insect undergoing a dramatic range shift is the mountain pine beetle (Dendroctonus ponderosae Hopkins). Ongoing eastward expansion by the mountain pine beetle through the previously climatically-unsuitable Canadian boreal forest may have large-scale impacts on north eastern North American pine forests.2.No systematic studies have been conducted on potential reproduction of mountain pine beetle on pines common to north eastern North America. We report reproduction of mountain pine beetle in logs of novel pine species (jack, Pinus banksiana Lamb; red, P. resinosa Ait.; eastern white, P. strobus L.; and Scots P. sylvestris L.) compared to the two most common pine hosts in its historical range (ponderosa, P. ponderosa Dougl. ex. Laws. var. scopulorum Engelm. and lodgepole P. contorta Dougl. var. latifolia Engelm.) in a two year study.3.Successful reproduction of mountain pine beetle occurred in all novel hosts, demonstrating that constitutive defences pose no barrier to further range expansion. Despite the number of progeny in novel hosts on par with that of historical hosts; approximately half of all brood that reached adulthood in novel hosts died prior to emergence.4.Increased brood mortality was correlated with the number of brood that developed to adulthood prior to winter, particularly in red pine. Brood developed more rapidly in novel vs. historical pine hosts, and, after overwintering due to a warm fall, exhibited less synchronized emergence in novel vs. historical hosts.5.Synthesis and applications. Outbreaks by an aggressive bark beetle may be possible outside its historical host range, but constrained by an interaction between host and seasonality. Our results suggest that pines common to north eastern North America are suitable hosts for mountain pine beetle and highlight the value of monitoring efforts and response preparations as the insect moves eastward.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-28T09:40:20.39297-05:0
      DOI: 10.1111/1365-2664.13064
       
  • Shifts in North Sea forage fish productivity and potential fisheries yield
    • Authors: Lotte W. Clausen; Anna Rindorf, Mikael Deurs, Mark Dickey-Collas, Niels T. Hintzen
      Abstract: Forage fish populations support large scale fisheries and are key components of marine ecosystems across the world, linking secondary production to higher trophic levels. While climate-induced changes in the North Sea zooplankton community are described and documented in literature, the associated bottom-up effects and consequences for fisheries remain largely unidentified.We investigated the temporal development in forage fish productivity and the associated influence on fisheries yield of herring, sprat, Norway pout and sandeel in the North Sea. Using principal component analysis, we analysed 40 years of recruitment success and growth proxies to reveal changes in productivity and patterns of synchroneity across stocks (i.e. functional complementarity). The relationship between forage fish production and Calanus finmarchicus (an indicator of climate change) was also analysed. We used a population model to demonstrate how observed shifts in productivity affected total forage fish biomass and fisheries yield.The productivity of North Sea forage fish changed around 1993 from a higher average productivity to lower average productivity. During the higher productivity period, stocks displayed a covariance structure indicative of functional complementarity. Calanus finmarchicus was positively correlated to forage fish recruitment, however, for growth, the direction of the response differed between species and time periods. Maximum sustainable yield (MSY) and the associated fishing mortality (Fmsy) decreased by 33%–68% and 26%–64%, respectively, between the higher and lower productivity periods.Synthesis and applications. The results demonstrate that fisheries reference points for short-lived planktivorous species are highly dynamic and respond rapidly to changes in system productivity. Furthermore, from an ecosystem-based fisheries management perspective, a link between functional complementarity and productivity, indicates that ecosystem resilience may decline with productivity. Based on this, we advise that system productivity, perhaps monitored as forage fish growth, becomes an integral part of management reference points; in both single species and ecosystem contexts. However, to retain social license of biological advice when fish catch opportunities are reduced, it is crucial that shifts in productivity are thoroughly documented and made apparent to managers and stakeholders.
      PubDate: 2017-11-27T19:01:02.68756-05:0
      DOI: 10.1111/1365-2664.13038
       
  • Corrigendum
    • PubDate: 2017-11-27T03:35:54.080357-05:
      DOI: 10.1111/1365-2664.13049
       
  • Model selection using information criteria, but is the ‘best’
           model any good'
    • Authors: Ralph Mac Nally; Richard P. Duncan, James R. Thomson, Jian D.L. Yen
      Abstract: 1.Information criteria (IC) are used widely for data summary and model building in ecology, especially in applied ecology and wildlife management. Although IC are useful for distinguishing among rival candidate models, IC do not necessarily indicate whether the ‘best’ model (or a model-averaged version) is a good representation of the data or whether the model has useful ‘explanatory’ or ‘predictive’ ability.2.As editors and reviewers, we have seen many submissions that did not evaluate whether the nominal ‘best’ model(s) found using IC is a useful model in the above sense.3.We scrutinized six leading ecological journals for papers that used IC to compare models. More than half of papers using IC for model comparison did not evaluate the adequacy of the best model(s) in either ‘explaining’ or ‘predicting’ the data.4.Synthesis and applications.
      Authors need to evaluate the adequacy of the model identified as the ‘best’ model by using information criteria methods to provide convincing evidence to readers and users that inferences from the best models are useful and reliable.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-27T02:45:37.896194-05:
      DOI: 10.1111/1365-2664.13060
       
  • Estimating animal density without individual recognition using information
           derivable exclusively from camera traps
    • Authors: Yoshihiro Nakashima; Keita Fukasawa, Hiromitsu Samejima
      Abstract: 1.Efficient and reliable methods for estimating animal density are essential to wildlife conservation and management. Camera trapping is an increasingly popular tool in this area of wildlife research, with further potential arising from technological improvements, such as video recording functions that allow for behavioural observation of animals. This information may be useful in the estimation of animal density, even without individual recognition. Although several models applicable to species lacking individual markings (i.e. unmarked populations) have been developed, a methodology incorporating behavioural information from videos has not yet been established.2.We developed a likelihood-based model: the random encounter and staying time (REST) model. It is an extension of the random encounter model (REM) by Rowcliffe et al. (2008). The REST model describes the relationship among staying time, trapping rate, and density, which is estimable using a frequentist or Bayesian approach. We tested the reliability and feasibility of the REST model using Monte Carlo simulations. We also applied the approach in the African rainforest and compared the results with those of a line-transect survey.3.The simulations showed that the REST model provided unbiased estimates of animal density. Even when animal movement speeds varied among individuals, and when animals travelled in pairs, the model provided unbiased density estimates. However, the REST model was vulnerable to unsynchronized activity patterns among individuals. Moreover, it is necessary to use a camera model with a fast and reliable infrared sensor, and to set the camera trap's parameters appropriately (i.e. video length, delay period). The field survey showed that the staying time of two ungulate species in the African rainforest exhibited good fit with a temporal parametric distribution, and the REST model provided density estimates consistent with those of a line-transect survey.4.Synthesis and applications. The random encounter and staying time (REST) model provides better efficiency and higher feasibility than the random encounter model in estimating animal density without individual recognition. Careful application of the REST model provides the potential to estimate density of many ground-dwelling vertebrates lacking individually recognizable markings, and thus should be an effective method for population monitoring.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-26T07:30:22.95578-05:0
      DOI: 10.1111/1365-2664.13059
       
  • Land use type, forest cover and forest edges modulate avian cross-habitat
           spillover
    • Authors: Andrea Larissa Boesing; Elizabeth Nichols, Jean Paul Metzger
      Abstract: Natural habitats adjacent to agricultural areas are often considered sources of species that provide beneficial regulating ecosystem services through cross-habitat spillover. Both inter-habitat matrix and landscape configuration can influence spillover by controlling organismal ability to disperse through landscapes, and affecting the provision of additional or supplementary resources that impact organism survival.To understand how landscape structure in terms of matrix land use type, forest cover and edge density might facilitate avian cross-habitat spillover, we sampled avian communities in forest patches and adjacent land use types (coffee plantations or cattle pastures) using a well-replicated study design across 92 sampling sites across a landscape-context forest cover gradient (6%–60%).Land use type was a key factor influencing avian cross-habitat spillover, facilitating species movement into coffee plantations and acting as a barrier to spillover into cattle pastures. We found that 24% of the forest-dependent species pool was capable of spillover into coffee plantations, while spillover was nearly non-existent in cattle pastures.Forest cover was also the main driver of spillover into coffee plantations. There was a positive relationship between forest cover and spillover, potentially due to processes related with (1) a higher density of organism in-patches, (2) decreased isolation among patches facilitating species movement and (3) higher landscape supplementation processes.Finally, we found edge density had an additive effect with forest cover on spillover. Spillover was higher in high-forested landscapes with many forest-matrix edges, possibly due to increased structural connectivity for species able to move through edges, and to improved access for forest-dwelling species to different resource types (complementation processes).Synthesis and applications. We demonstrate that land use type is a key factor facilitating species spillover into agricultural matrices and that the influence of land use type on spillover is further modulated by a combination of native habitat amount and edge density. These results should be considered in efforts to design or manage sustainable agricultural landscapes in order to enhance both bird persistence and the provision of bird-mediated ecosystem services.
      PubDate: 2017-11-22T23:10:55.623765-05:
      DOI: 10.1111/1365-2664.13032
       
  • Is saltmarsh restoration success constrained by matching natural
           environments or altered succession' A test using niche models
    • Authors: Martin J. P. Sullivan; Anthony J. Davy, Alastair Grant, Hannah L. Mossman
      Abstract: Restored habitats, such as saltmarsh created through managed realignment, sometimes fail to meet targets for biological equivalence with natural reference sites. Understanding why this happens is important in order to improve restoration outcomes.Elevation in the tidal frame and sediment redox potential are major controls on the distribution of saltmarsh plants. We use niche models to characterize 10 species’ responses to these, and test whether differences in species occurrence between restored and natural saltmarshes in the UK result from failure to recreate adequate environmental conditions.Six species occurred less frequently in recently restored marshes than natural marshes. Failure of restored marshes to achieve the elevation and redox conditions of natural marshes partially explained the underrepresentation of five of these species, but did not explain patterns of occurrence on older (>50 years) restored marshes.For all species, an effect of marsh age remained after controlling for differences in environmental conditions. This could be due to differences in successional mechanism between restored and natural marshes. In recently restored marshes, high-marsh species occurred lower in the tidal frame and low-marsh species occurred higher in the tidal frame than in natural marshes. This supports the hypothesis that competition is initially weaker in restored marshes, because of the availability of bare sediment across the whole tidal frame. Species that establish outside their normal realized niche, such as Atriplex portulacoides, may inhibit subsequent colonization of other species that occurred less frequently than expected on older restored marshes.Synthesis and applications. Niche models can be used to test whether abiotic differences between restored sites and their natural counterparts are responsible for discrepancies in species occurrence. In saltmarshes, simply replicating environmental conditions will not result in equivalent species occurrence.
      PubDate: 2017-11-22T23:10:42.886586-05:
      DOI: 10.1111/1365-2664.13033
       
  • Plant, herbivore and parasitoid community composition in native
           Nothofagaceae forests vs. exotic pine plantations
    • Authors: Guadalupe Peralta; Carol M. Frost, Raphael K. Didham
      Abstract: 1.Converting natural areas into land used for production causes dramatic changes in the configuration of landscapes. Both the loss and fragmentation of native habitats contribute to biodiversity loss worldwide and the consequent creation of artificial edges can have a significant influence on community assembly. The conservation value of plantation forests has been identified for specific species, but it is not clear whether exotic pine plantations can also be used for the preservation of native communities in general.2.We studied whether community composition of different trophic levels (plants, herbivorous caterpillars, parasitoids) changed across native Nothofagaceae forests to exotic pine plantations, and whether habitat edges affected communities differently depending on the forest type considered. To accomplish this, we sampled plants, herbivorous caterpillars and parasitoids in native Nothofagaceae and exotic pine plantation forests and compared community composition of each trophic level across habitats.3.We found that community composition of plants, herbivorous caterpillars and parasitoids differed significantly between native and exotic plantation forests, and that variation in the composition of the upper trophic levels was strongly dependent on variation in the composition of the lower trophic level. Moreover, differences in community composition were mostly the result of species turnover, suggesting that plantations are complementary habitats for some species, but cannot be a substitute habitat for all native forest species. Furthermore, edge effects had a strong impact on the composition of native communities, such that certain species were only present in the interior of the native habitat.4.Synthesis and applications. Large areas of native vegetation, where the interior remains intact, are essential to preserve species that are susceptible to edge effects and that cannot occupy other habitat types. Creating straight instead of winding edges could decrease the impact that plantations have on native forests. Furthermore, increasing the representativeness of native plant communities in exotic plantation forests would cascade up to higher consumer trophic levels, considerably increasing the conservation value of these commercial stands.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-22T04:01:09.794561-05:
      DOI: 10.1111/1365-2664.13055
       
  • Ex situ cultivation entails high risk of seed dormancy loss on short-lived
           wild plant species
    • Authors: Andreas Ensslin; Ann Vyver, Thierry Vanderborght, Sandrine Godefroid
      Abstract: 1.Changes in life-history traits such as seed dormancy during cultivation of wild plant species in ex situ facilities could jeopardise conservation actions including revegetation and plant reintroductions, but the magnitude of these risks and their spread across different plant taxa is unknown.2.We explored whether plants cultivated in the Botanic Garden Meise differ in seed germination characteristics from plants from natural populations. Using a Bayesian approach of a phylogenetically informed generalized linear mixed model, we analysed germination tests of 72 herbaceous plant species from 27 plant families, originating from the cultivation beds in Meise as well as directly from wild populations. We investigated whether garden-collected seeds differ in germination percentage, seed dormancy and germination speed from wild-collected seeds. Furthermore, by analysing literature-collected information of 24 life-history traits, we sought to identify potential selection pressures causing these germination changes in order to refine conservation protocols and practices.3.We found a strong increase of germination percentage and a loss of seed dormancy in garden seeds compared to wild seeds across all species. However, these differences vanished with increasing storage time of the seeds as a result of decreased seed viability with seed aging over time.4.Furthermore, traits associated with the life span of the species influenced the germination difference between cultivated and wild seeds, and short-lived species were particularly vulnerable to the loss of dormancy, while no difference could be detected between wild and cultivated perennial species.5.Synthesis and applications. Through a multi-species approach, we show that dormancy loss is a common phenomenon in ex situ collections of short-lived wild plant species. This has wide implications for the use and procedure of ex situ reared plant material for restoration and reintroduction measures. We suggest that effective dormancy breaking and temporal distribution of seedling plantation during propagation should be incorporated in restoration and reintroduction protocols to minimize unwanted changes in seed traits. Furthermore, we caution against the use of seeds from cultivated plants for basic seed ecology research such as germination requirements and seed storage behaviour.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-22T02:20:48.828047-05:
      DOI: 10.1111/1365-2664.13057
       
  • Metacommunities, metaecosystems, and the environmental fate of chemical
           contaminants
    • Authors: Luis Schiesari; Mathew A. Leibold, G. Allen Burton
      Abstract: 1.Although pollution is a major driver of ecosystem change, models predicting the environmental fate of contaminants suffer from critical uncertainties related to oversimplifying the dynamics of the biological compartment.2.It is increasingly recognized that contaminant processing is an outcome of ecosystem functioning, that ecosystem functioning is contingent on community structure, and that community structure is influenced by organismal dispersal. We propose a conceptual organization of the contribution of organismal dispersal to local contaminant fate. Direct dispersal effects occur when the dispersing organism directly couples contaminant stocks in spatially separate ecosystems by transporting contaminants in its biomass. Indirect dispersal effects occur when the dispersing organism indirectly influences contaminant fate via community assembly. This can occur either when the dispersing organism is a contaminant processor or when the dispersing organism alters, via species interactions, the abundance of contaminant biotransporters or processors already established in the ecosystem. The magnitude of direct and indirect dispersal effects are modulated by many factors, including other contaminants. These will influence population growth rates of the dispersing species in the donor ecosystem, or the probability that a dispersing individual reaches the recipient ecosystem.3.We provide a review of pertinent literature demonstrating that these two mechanisms, and their chemical modulation, are well supported or likely to occur in many natural and human-modified landscapes. The literature also demonstrates that they can operate in concert with each other.4.Synthesis and applications. This research provides recommendations for environmental management, monitoring, model development and funding policy. Managed ecosystems thought to be important contaminant and nutrient sinks, such as artificial ponds and constructed wetlands, should be monitored and controlled for in-and-out animal movement if contaminant export is found to be relevant. Uncontaminated fishing grounds linked to contaminated sites via movement of dispersing species should be monitored and resident species evaluated for health consumption advisories. Assessing the success of contaminated site remediation can be improved by better matching the spatial extent of site remediation and the home range of monitored species. Finally, interagency research fund programs should be developed that narrow the current gap between the fields of ecology and ecotoxicology.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-22T02:15:21.643487-05:
      DOI: 10.1111/1365-2664.13054
       
  • Accommodating temporary emigration in spatial distance sampling models
    • Authors: Jeremy D. Mizel; Joshua H. Schmidt, Mark S. Lindberg
      Abstract: 1.Model-based distance sampling is commonly used to understand spatial variation in the density of wildlife species. The standard approach assumes that individuals are distributed uniformly and models spatial variation in density using plot-level effects. Thinned point process (TPP) models for surveys of unmarked populations (spatial distance sampling) better leverage the spatial information underlying individual encounters, and in the presence of within-plot variation in density, may explain a larger proportion of the spatial variation in density. However, existing spatial distance sampling approaches are conditioned on the assumption that all individuals are present and available for sampling. Temporary emigration of individuals can therefore result in biased estimates of abundance.2.We extended spatial distance sampling models to accommodate temporary emigration (TPP model). Using simulations of a thinned inhomogeneous point process, we assessed the performance of the TPP model relative to the temporary emigration distance sampling (TEDS) model, which implies a uniform distribution of individuals. In addition, we compared inferences between TPP and TEDS models using data for two passerine species in Alaska.3.Parameter estimates from the TPP model exhibited improved coverage probability and precision relative to the TEDS model including a 26% reduction in the coefficient of variation (CV) of the population size estimate.4.In the applied example, the TEDS model indicated weak relationships between abundance and habitat covariates, whereas the TPP model indicated strong relationships for those same effects, suggesting that spatial distance sampling models can provide considerably stronger inference in the presence of within-plot variation in density. In addition, the CV of the population size estimates for the two passerine species were 32% and 4% smaller under the TPP model.5.Synthesis and applications. We expect our extension accommodating temporary emigration will be a critical specification for spatial distance sampling models, particularly for studies assessing changes in the distribution and abundance of highly mobile species including passerines.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-22T01:35:27.154583-05:
      DOI: 10.1111/1365-2664.13053
       
  • High-productivity vegetation is important for lessening bird declines
           during prolonged drought
    • Authors: Katherine E. Selwood; Melodie. A. McGeoch, Rohan H. Clarke, Ralph Mac Nally
      Abstract: 1.Locations in which ecological assemblages show high resistance to climate pressures, such as drought, are likely to be important refuges for biota in changing climates. We asked whether environmental characteristics of locations were associated with the capacity of bird assemblages to withstand prolonged drought.2.We used a multi-species index to quantify trends in bird assemblages during a 13-year drought at>500 locations (>18,000 surveys) in the Murray-Darling Basin, south eastern Australia, using data from the Atlas of Australian Birds. We investigated whether the resistance of bird assemblages was associated with: (1) vegetation structure; (2) vegetation productivity (vegetation greenness); (3) landscape context (patch size, landscape vegetation cover); or (4) physical environment (elevation, terrain, topography, availability of surface water).3.Vegetation productivity, measured by vegetation greenness (Normalized Difference Vegetation Index), was the only potential predictor with strong evidence of an effect, and was positively associated with the index of drought resistance. There was little evidence that variables characterising landscape context, vegetation structure or the physical environment of sites were associated with drought resistance of bird communities.4.Synthesis and applications. Bird assemblages in locations with high vegetation greenness are more resistant to severe drought. Prioritizing conservation investments in areas with locally high vegetation productivity is likely to be an effective strategy for increasing the resistance of bird assemblages to extreme drought, especially in areas where mean productivity is relatively low, such as arid and semi-arid regions. Remotely sensed vegetation greenness may be a promising source of information for identifying drought refuges for birds and possibly other biota.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-21T22:45:47.783496-05:
      DOI: 10.1111/1365-2664.13052
       
  • Managing seagrass resilience under cumulative dredging affecting light:
           Predicting risk using dynamic Bayesian networks
    • Authors: Paul Pao-Yen Wu; Kathryn McMahon, Michael A. Rasheed, Gary A. Kendrick, Paul H. York, Kathryn Chartrand, M. Julian Caley, Kerrie Mengersen
      Abstract: Coastal development is contributing to ongoing declines of ecosystems globally. Consequently, understanding the risks posed to these systems, and how they respond to successive disturbances, is paramount for their improved management. We study the cumulative impacts of maintenance dredging on seagrass ecosystems as a canonical example. Maintenance dredging causes disturbances lasting weeks to months, often repeated at yearly intervals.We present a risk-based modelling framework for time varying complex systems centred around a dynamic Bayesian network (DBN). Our approach estimates the impact of a hazard on a system's response in terms of resistance, recovery and persistence, commonly used to characterise the resilience of a system. We consider whole-of-system interactions including light reduction due to dredging (the hazard), the duration, frequency and start time of dredging, and ecosystem characteristics such as the life-history traits expressed by genera and local environmental conditions.The impact on resilience of dredging disturbances is evaluated using a validated seagrass ecosystem DBN for meadows of the genera Amphibolis (Jurien Bay, WA, Australia), Halophila (Hay Point, Qld, Australia) and Zostera (Gladstone, Qld, Australia). Although impacts varied by combinations of dredging parameters and the seagrass meadows being studied, in general, 3 months of duration or more, or repeat dredging every 3 or more years, were key thresholds beyond which resilience can be compromised. Additionally, managing light reduction to less than 50% can significantly decrease one or more of loss, recovery time and risk of local extinction, especially in the presence of cumulative stressors.Synthesis and applications. Our risk-based approach enables managers to develop thresholds by predicting the impact of different configurations of anthropogenic disturbances being managed. Many real-world maintenance dredging requirements fall within these parameters, and our results show that such dredging can be successfully managed to maintain healthy seagrass meadows in the absence of other disturbances. We evaluated opportunities for risk mitigation using time windows; periods during which the impact of dredging stress did not impair resilience.
      PubDate: 2017-11-21T19:01:02.312595-05:
      DOI: 10.1111/1365-2664.13037
       
  • Farmer perception and utilization of leaf functional traits in managing
           agroecosystems
    • Authors: Marney E. Isaac; Rolando Cerda, Bruno Rapidel, Adam R. Martin, Adam K. Dickinson, Nicole Sibelet
      Abstract: Using knowledge of leaf functional traits, such as those forming the leaf economics spectrum (LES), to understand plant responses to environmental change is well-established and now being more widely applied to agroecosystems. Yet, little is known about how farm managers invoke leaf functional traits to inform management decisions.The objectives of this research were to (1) evaluate whether farmers use knowledge of intraspecific trait variation (ITV) in LES traits (or trait proxies) of target crops as response indicators of management conditions; (2) determine whether LES trait values are ranked consistently among multiple farmers along a “Farmer Leaf Economics Spectrum” (FES); (3) evaluate how a FES corresponds to the LES; and (4) identify the farmer and farm attributes that best predict the agreement between the FES and the LES.We collaborated with coffee (Coffea arabica) farmers in the Turrialba Valley, Costa Rica. We used a visual elicitation tool of fresh leaves along an intraspecific spectrum of leaf size, leaf thickness and leaf colour (as a proxy for leaf nutrients); respondents were asked to rank leaves in response to shade and nutrient scenarios as well as yield potential. On-farm biophysical data, management practices and socio-economic attributes were also collected.The majority of farmers demonstrated a developed system of utilizing coffee leaf and whole-plant ITV as indicators of management practices. Farmers managing smaller farms tended to more commonly acknowledge ITV in LES chemical–morphological traits, as compared to those managing large farms. The agreement between a respondent-identified ranking of leaf thickness ITV as a function of light environment and an empirically defined thickness-to-light ranking was partially explained by farmers’ physical engagement with plants.Synthesis and applications. In scientific literature, analyses of crop intraspecific trait variation have provided important insights into the mechanistic bases of multiple key agroecological processes. We demonstrate that farmers use crop leaf trait variation as an indicator to both evaluate management prescriptions and to initiate management actions including shade-tree species selection and abundance, crop- and shade-tree pruning regimes and fertilization treatments. These findings signify that functional traits represent a key nexus between scientific and local knowledge.
      PubDate: 2017-11-16T23:25:37.561762-05:
      DOI: 10.1111/1365-2664.13027
       
  • Developing a framework of minimum standards for the risk assessment of
           alien species
    • Authors: Helen E. Roy; Wolfgang Rabitsch, Riccardo Scalera, Alan Stewart, Belinda Gallardo, Piero Genovesi, Franz Essl, Tim Adriaens, Sven Bacher, Olaf Booy, Etienne Branquart, Sarah Brunel, Gordon Howard Copp, Hannah Dean, Bram D'hondt, Melanie Josefsson, Marc Kenis, Marianne Kettunen, Merike Linnamagi, Frances Lucy, Angeliki Martinou, Niall Moore, Wolfgang Nentwig, Ana Nieto, Jan Pergl, Jodey Peyton, Alain Roques, Stefan Schindler, Karsten Schönrogge, Wojciech Solarz, Paul D. Stebbing, Teodora Trichkova, Sonia Vanderhoeven, Johan Valkenburg, Argyro Zenetos
      Abstract: Biological invasions are a threat to biodiversity, society and the economy. There is an urgent need to provide evidence-based assessments of the risks posed by invasive alien species (IAS) to prioritize action. Risk assessments underpin IAS policies in many ways: informing legislation; providing justification of restrictions in trade or consumer activities; prioritizing surveillance and rapid response. There are benefits to ensuring consistency in content of IAS risk assessments globally, and this can be achieved by providing a framework of minimum standards as a checklist for quality assurance.From a review of existing risk assessment protocols, and with reference to the requirements of the EU Regulation on IAS (1143/2014) and international agreements including the World Trade Organisation, Convention on Biological Diversity and International Plant Protection Convention, coupled with consensus methods, we identified and agreed upon 14 minimum standards (attributes) a risk-assessment scheme should include.The agreed minimum standards were as follows: (1) basic species description; (2) likelihood of invasion; (3) distribution, spread and impacts; (4) assessment of introduction pathways; (5) assessment of impacts on biodiversity and ecosystems; (6) Assessment of impact on ecosystem services; (7) assessment of socio-economic impacts; (8) consideration of status (threatened or protected) of species or habitat under threat; (9) assessment of effects of future climate change; (10) completion possible even when there is a lack of information; (11) documents information sources; (12) provides a summary in a consistent and interpretable form; (13) includes uncertainty; (14) includes quality assurance. In deriving these minimum standards, gaps in knowledge required for completing risk assessments and the scope of existing risk assessment protocols were revealed, most notably in relation to assessing benefits, socio-economic impacts and impacts on ecosystem services but also inclusion of consideration of climate change.Policy implications. We provide a checklist of components that should be within invasive alien species risk assessments and recommendations to develop risk assessments to meet these proposed minimum standards. Although inspired by implementation of the European Union Regulation on invasive alien species, and as such developed specifically within a European context, the derived framework and minimum standards could be applied globally.
      PubDate: 2017-11-16T23:25:29.852076-05:
      DOI: 10.1111/1365-2664.13025
       
  • Staged-Scale Restoration: Refining Adaptive Management to Improve
           Restoration Effectiveness
    • Authors: Jonathan D. Bakker; Eric G. Delvin, Peter W. Dunwiddie
      Abstract: 1.Adaptive management (AM) was proposed as a rigorous and structured approach to natural resource management that increases learning and reduces uncertainty. It has been adopted as a guiding principle by agencies worldwide, yet its usefulness for guiding management continues to be debated. We propose a new strategy, which we term staged-scale restoration (SSR), to implement AM in a restoration setting while enhancing the scientific rigor, ecological effectiveness, and overall efficiency of restoration efforts compared to traditional applications of AM.2.The SSR approach includes three aspects: i) experimentally assessing alternative restoration techniques directly on-site in replicated plots using operational-scale equipment, ii) staging, or the successive establishment and evaluation of treated areas over time, and iii) scaling, whereby the most successful techniques identified during earlier stages are applied to increasingly larger areas in later stages. A case study illustrates how SSR was used to improve prairie restoration in western Washington, USA.3.SSR provides several key advantages. It includes a robust experimental design and thus improves the scientific rigor of AM. It is conducted on site using operational-scale equipment and thus increases the effectiveness of treatments while also providing a platform for refining existing treatments. SSR facilitates collaboration among researchers and managers. By promoting advanced planning and deferring much of the area to be treated to the latter years of a project, SSR reduces the risk of restoration failure. Finally, it is extremely flexible: it can be implemented at multiple sites or years, the number and types of treatments to be assessed can be customized, and the pace of restoration can be varied.4.Synthesis and applications. Staged-scale restoration addresses many of the criticisms that have been directed at conventional adaptive management (AM) and provides a scientifically rigorous strategy to improve restoration while customizing treatments for individual sites. It explicitly enables restoration projects to be conducted within an AM framework, and clearly and intentionally integrates ecological research into restoration efforts. We urge the restoration community to explore the utility of staged-scale restoration in diverse socioeconomic circumstances and ecosystems.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-16T03:50:23.7046-05:00
      DOI: 10.1111/1365-2664.13050
       
  • The added value of including key microbial traits to determine
           nitrogen-related ecosystem services in managed grasslands
    • Authors: Thomas Pommier; Amélie A. M. Cantarel, Karl Grigulis, Sandra Lavorel, Nicolas Legay, Catherine Baxendale, Richard D. Bardgett, Michael Bahn, Franck Poly, Jean-Christophe Clément
      Abstract: Despite playing central roles in nutrient cycles and plant growth, soil microbes are generally neglected in the study of ecosystem services (ES), due to difficulties to assess their diversity and functioning. However, to overcome these hurdles, new conceptual approaches and modern tools now provide a means to assess the role of micro-organisms in the evaluation of ES.In managed grasslands, soil microbes are central in providing nitrogen (N)-related ES such as maintenance of soil fertility and retention of mineral forms of N. Here, we applied state-of-the-art techniques in microbial ecology and plant functional ecology to uncover the intrinsic link between N-related bacterial functional groups, important plant functional traits, environmental factors and three proxies of maintenance of soil fertility and potential for N-leaching across managed grasslands in three regions of Europe.By constructing well-defined structural equation modelling, we showed that including key microbial traits improve on average more than>50% of the total variances of ES proxies, that is, ammonium (NH4+) or nitrate (NO3−) leaching, and soil organic matter content. Geographic differences arose when considering the direct relationships of these ES proxies with specific microbial traits: nitrate leaching was positively correlated to the maximum rate of nitrification, except in the Austrian site and potentially leached NH4+–N was negatively correlated to the fungi/bacteria ratio, with the exception of the French site.Synthesis and applications. The integration of soil microbial functional traits in the assessment of nitrogen-related grassland ecosystem services has direct contributions for understanding sustainable management of grassland ecosystems. The fundamental aspects of this study suggest that integrating a soil microbial component in grassland management may enhance sustainability of such grass-based agroecosystems.
      PubDate: 2017-11-13T23:45:34.254882-05:
      DOI: 10.1111/1365-2664.13010
       
  • Is environmental legislation conserving tropical stream faunas' A
           large-scale assessment of local, riparian and catchment-scale influences
           on Amazonian fish
    • Authors: Cecília G. Leal; Jos Barlow, Toby A. Gardner, Robert M. Hughes, Rafael P. Leitão, Ralph Mac Nally, Philip R. Kaufmann, Silvio F. B. Ferraz, Jansen Zuanon, Felipe R. Paula, Joice Ferreira, James R. Thomson, Gareth D. Lennox, Eurizângela P. Dary, Cristhiana P. Röpke, Paulo S. Pompeu
      Abstract: Agricultural expansion and intensification are major threats to tropical biodiversity. In addition to the direct removal of native vegetation, agricultural expansion often elicits other human-induced disturbances, many of which are poorly addressed by existing environmental legislation and conservation programmes. This is particularly true for tropical freshwater systems, where there is considerable uncertainty about whether a legislative focus on protecting riparian vegetation is sufficient to conserve stream fauna.To assess the extent to which stream fish are being effectively conserved in agricultural landscapes, we examined the spatial distribution of assemblages in river basins to identify the relative importance of human impacts at instream, riparian and catchment scales, in shaping observed patterns. We used an extensive dataset on the ecological condition of 83 low-order streams distributed in three river basins in the eastern Brazilian Amazon.We collected and identified 24,420 individual fish from 134 species. Multiplicative diversity partitioning revealed high levels of compositional dissimilarity (DS) among stream sites (DS = 0.74 to 0.83) and river basins (DS = 0.82), due mainly to turnover (77.8% to 81.8%) rather than nestedness. The highly heterogeneous fish faunas in small Amazonian streams underscore the vital importance of enacting measures to protect forests on private lands outside of public protected areas.Instream habitat features explained more variability in fish assemblages (15%–19%) than riparian (2%–12%), catchment (4%–13%) or natural covariates (4%–11%). Although grouping species into functional guilds allowed us to explain up to 31% of their abundance (i.e. for nektonic herbivores), individual riparian – and catchment – scale predictor variables that are commonly a focus of environmental legislation explained very little of the observed variation (partial R2 values mostly
      PubDate: 2017-11-12T23:10:40.945539-05:
      DOI: 10.1111/1365-2664.13028
       
  • Large woody debris “rewilding” rapidly restores biodiversity
           in riverine food webs
    • Authors: Murray S. A. Thompson; Stephen J. Brooks, Carl D. Sayer, Guy Woodward, Jan C. Axmacher, Daniel M. Perkins, Clare Gray
      Abstract: Extensive habitat destruction and pollution have caused dramatic declines in aquatic biodiversity at local to global scales. In rivers, the reintroduction of large woody debris is a common method aimed at restoring degraded ecosystems through “rewilding.” However, causal evidence for its effectiveness is lacking due to a dearth of replicated before–after control-impact field experiments.We conducted the first replicated experiment of large woody debris rewilding across multiple rivers and organisational levels, from individual target species populations to entire food webs.For the first time, we demonstrate causal links between habitat restoration, biodiversity restoration and food web responses. Populations of invertebrates and an apex predator, brown trout (Salmo trutta), increased, and food web analysis suggested increased biomass flux from basal resources to invertebrates and subsequently fishes within restored reaches.Synthesis and applications. This study contributes significant new evidence demonstrating that large woody debris rewilding can help to restore human-impacted river ecosystems, primarily through altering the abundance and biomass of consumers and resources in the food web. We also outline a means to gauge the magnitude of ecological responses to restoration, relative to environmental stressors, which could help to prioritise the most effective conservation efforts.
      PubDate: 2017-11-12T23:05:43.001363-05:
      DOI: 10.1111/1365-2664.13013
       
  • Elevated salinity blocks pathogen transmission and improves host survival
           from the global amphibian chytrid pandemic: Implications for
           translocations
    • Authors: Simon Clulow; John Gould, Hugh James, Michelle Stockwell, John Clulow, Michael Mahony
      Abstract: Emerging infectious diseases are one of the greatest threats to global biodiversity. Chytridiomycosis in amphibians is perhaps the most extreme example of this phenomenon known to science. Translocations are increasingly used to fight disease-induced extinctions. However, many programmes fail because disease is still present or subsequently establishes in the translocation environment. There is a need for studies in real-world scenarios to test whether environmental manipulation could improve survival in populations by generating unfavourable environmental conditions for pathogens. Reintroductions of amphibians impacted by chytridiomycosis into environments where the disease persists provide a scenario where this paradigm can be tested.We tested the hypothesis that manipulating environmental salinity in outdoor mesocosms under near-identical environmental conditions, present in a nearby translocation programme for an endangered amphibian, would improve survival and determine the mechanisms involved. One hundred and sixty infected and 288 uninfected, captive-bred, juvenile frogs were released into 16 outdoor mesocosms in which salinity was controlled (high- or low-salinity treatment). The experiment was run for 25 weeks from the mid-austral winter to the mid-austral summer of 2013 in a temperate coastal environment, Australia.Increasing salinity from c. 0.5 ppt to 3.5–4.5 ppt reduced pathogen transmission between infected and uninfected animals, resulting in significantly reduced mortality in elevated salt mesocosms (0.13, high-salt vs. 0.23, low-salt survival at 23 weeks). Increasing water temperature associated with season (from mean 13 to 25°C) eventually cleared all surviving animals of the pathogen.Synthesis and applications. We identified a mechanism by which environmental salinity can protect amphibian hosts from chytridomycosis by reducing disease transmission rates. We conclude that manipulating environmental salinity in landscapes where chytrid-affected amphibians are currently translocated could improve the probability of population persistence for hundreds of species. More broadly, we provide support for the paradigm that environmental manipulation can be used to mitigate the impact of emerging infectious diseases.
      PubDate: 2017-11-12T23:05:29.580328-05:
      DOI: 10.1111/1365-2664.13030
       
  • Demonstrating multiple benefits from periodically harvested fisheries
           closures
    • Authors: Jordan S. Goetze; Joachim Claudet, Fraser Januchowski-Hartley, Tim J. Langlois, Shaun K. Wilson, Crow White, Rebecca Weeks, Stacy D. Jupiter
      Abstract: 1.Periodically harvested closures (PHCs) are one of the most common forms of fisheries management in Melanesia, demonstrating multiple objectives, including sustaining fish stocks and increasing catch efficiency to support small-scale fisheries. No studies have comprehensively assessed their ability to provide short-term fisheries benefits across the entire harvest regime.2.We present a novel analytical framework to guide a meta-analysis and assist future research in conceptualizing and assessing the potential of PHCs to deliver benefits for multiple fisheries-related objectives.3.Ten PHCs met our selection criteria and on average, they provided a 48% greater abundance and 92% greater biomass of targeted fishes compared with areas open to fishing prior to being harvested.4.This translated into tangible harvest benefits, with fishers removing 21% of the abundance and 49% of the biomass within PHCs, resulting in few post-harvest protection benefits.5.When PHCs are larger, closed for longer periods or well enforced, short-term fisheries benefits are improved. However, an increased availability of fish within PHCs leads to greater removal during harvests.6.Synthesis and applications. Periodically harvested closures (PHCs) can provide short-term fisheries benefits. Use of the analytical framework presented here will assist in determining long term fisheries and conservation benefits. We recommend PHCs be closed to fishing for as long as possible, be as large as possible, that compliance be encouraged via community engagement and enforcement, and strict deadlines/goals for harvesting set to prevent overfishing.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-12T07:00:23.263924-05:
      DOI: 10.1111/1365-2664.13047
       
  • Abandoned pastures cannot spontaneously recover the attributes of
           old-growth savannas
    • Authors: Mário G. B. Cava; Natashi A. L. Pilon, Milton Cezar Ribeiro, Giselda Durigan
      Abstract: 1.Active restoration strategies have been recommended to recover Neotropical savannas in abandoned lands, but no studies have investigated the trajectories and speeds of spontaneous recovery for these systems. Research into the dynamics of degraded savannas is urgently needed to guide restoration decision-making.2.We analysed the dynamics of secondary savannas in the Brazilian Cerrado by sampling 29 abandoned pastures (time since abandonment ranging from 3 to 25 years) and applying the space-for-time substitution method. We modelled the temporal changes in plant community attributes and estimated the time (years) required for these attributes to match those of two reference ecosystems (three replicates each), old-growth savanna and a forest-type savanna, which had encroached following fire suppression (encroached savanna). We also analysed the plant community composition of the study sites.3.Our models showed that tree canopy cover, richness and density rapidly increased with time since pasture abandonment, easily surpassing the values of the old-growth savanna (28 years) and reaching the values of encroached savanna 49 years after abandonment. The cover and richness of the ground layer increased at a much slower pace. Since the species in this layer, including the exotic grasses, are shade intolerant, they will be eliminated by canopy closure over time.4.Up to 25 years after abandonment, secondary savannas continued to lack many (37%) old-growth savanna species, mostly from the ground layer (82% of grasses absent). This period was also not sufficient for the secondary savannas to become floristically similar to the encroached savannas, which are dominated by shade-tolerant tree species.5.Synthesis and applications. Despite the reported high natural regeneration of Neotropical savanna vegetation, abandoned pastures will not spontaneously return to an old-growth savanna state. Protected from fire and lacking the native ground layer, the end state of secondary savannas will be a low-diversity forest. If restoration goals include the recovery of old-growth savanna biodiversity and structure, interventions are required to prevent woody encroachment and reintroduce native grasses, forbs and shrubs. However, if the desirable endpoint is a low-diversity forest, passive restoration (non-intervention) and fire protection are appropriate.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-12T07:00:21.092556-05:
      DOI: 10.1111/1365-2664.13046
       
  • A review of riverine ecosystem service quantification: research gaps and
           recommendations
    • Authors: Dalal E.L. Hanna; Stephanie A. Tomscha, Camille Ouellet Dallaire, Elena M. Bennett
      Abstract: 1.Increasing demand for benefits provided by riverine ecosystems threatens their sustainable provision. The ecosystem service concept is a promising avenue to inform riverine ecosystem management, but several challenges have prevented the application of this concept.2.We quantitatively assess the field of riverine ecosystem services’ progress in meeting these challenges. We highlight conceptual and methodological gaps, which have impeded integration of the ecosystem service concept into management.3.Across 89 relevant studies, 33 unique riverine ecosystem services were evaluated, for a total of 404 ecosystem service quantifications. Studies quantified between one and 23 ecosystem services, although the majority (55%) evaluated three or less. Among studies that quantified more than one service, 58% assessed interactions between services. Most studies (71%) did not include stakeholders in their quantification protocols, and 34% developed future scenarios of ecosystem service provision. Almost half (45%) conducted monetary valuation, using 16 methods. Only 9% did not quantify or discuss uncertainties associated with service quantification. The indicators and methods used to quantify the same type of ecosystem service varied. Only 3% of services used indicators of capacity, flow, and demand in concert.4.Our results suggest indicators, data sources, and methods for quantifying riverine ecosystem services should be more clearly defined and accurately represent the service they intend to quantify. Furthermore, more assessments of multiple services across diverse spatial extents and of riverine service interactions are needed, with better inclusion of stakeholders. Addressing these challenges will help riverine ecosystem service science inform river management.5.Synthesis and applications. The ecosystem service concept has great potential to inform riverine ecosystem management and decision making processes. However, this review of riverine ecosystem service quantification uncovers several remaining research gaps, impeding effective use of this tool to manage riverine ecosystems. We highlight these gaps and point to studies showcasing methods that can be used to address them.This article is protected by copyright. All rights reserved.
      PubDate: 2017-11-12T06:55:22.850985-05:
      DOI: 10.1111/1365-2664.13045
       
  • Species wood density and the location of planted seedlings drive
           early-stage seedling survival during tropical forest restoration
    • Authors: Lachlan S. Charles; John M. Dwyer, Tobias J. Smith, Sophie Connors, Petra Marschner, Margaret M. Mayfield
      Abstract: The success of restoration projects is known to vary widely, with outcomes relating to numerous biotic and abiotic factors. Though many studies have examined the factors associated with long-term restoration success, few have examined which factors impact the establishment of restoration plantings.In Australia's Wet Tropics, we used a large replicated restoration experiment to assess seedling survival for 24 native rainforest species commonly used in local restoration efforts. The experiment allowed for a rigorous assessment of the effects of species functional traits, planting conditions, and landscape- and local-scale biotic and abiotic factors on seedling survival. This study reports on seedling survival between three different time periods of 0–4, 4–9 and 9–31 months post planting.The probability of seedling survival was influenced by multiple factors, varying in importance over time. Across the whole study period, seedlings with high wood density and which were planted closer to intact forest consistently displayed the highest probabilities of survival. Transient factors affecting seedling survival across the three time periods included plot aspect (0–4 months only), the identity of the planter and slope (4–9 and 9–31 months). Overall, species survival did not differ between the low (6 species) and high (24 species) diversity treatments, but was significantly lower in monocultures of Flindersia brayleyana by the end of the study.We demonstrate that early-stage seedling survival depends on species wood density and planting location. Our results support the use of species with more conservative growth strategies when limited funds are available for follow-up plantings. High wood density species had significantly higher survival than lower wood density, early successional species typically used in rainforest restoration plantings.Synthesis and applications. Our study highlights the importance of wood density and landscape structure to the initial survival of rainforest plantings. Factors influencing seedling survival shifted over time but, most importantly, our results highlight that, when planting into abandoned pastures, it may be preferable to select species with higher wood densities to maximize survival during the crucial early stages of establishment and growth.
      PubDate: 2017-11-10T01:50:30.150487-05:
      DOI: 10.1111/1365-2664.13031
       
  • Applying a biocomplexity approach to modelling farmer decision-making and
           land use impacts on wildlife
    • Authors: Anna Malawska; Christopher John Topping
      Abstract: The biocomplexity approach refers to a fully integrated social-ecological systems (SES) simulation that represents bidirectional feedbacks between social and ecological components. This method is essential to accurately assess impacts of economy and policy on SES such as agroecosystems, where feedbacks between the drivers and impacts of cropping changes need to be simulated. Here we exemplify the biocomplexity approach using energy maize, which is becoming an important source of bioenergy in Europe, and thus, might cause a significant change in land use with knock on-effects for wildlife.The integrated simulation tool consisted of a farmer decision-making agent-based model fully coupled to the Animal Landscape and Man Simulatin System (ALMaSS), an agent-based simulation system for predicting impacts of land use on a range of Danish wildlife species: the brown hare (Lepus europaeus), the grey partridge (Perdix perdix), the skylark (Alauda arvensis), a carabid beetle (Bembidion lampros), a linyphiid spider (Erigone atra) and the field vole (Microtus agrestis). This was used to assess the impacts of increasing demand on energy maize on the six animal species. Two types of experimental scenarios were evaluated, with and without feedback between the social and ecological system. The assessment of species responses was based on changes in population size, abundance and occupancy.The response to the cultivation of energy maize was negative for three vertebrate species (skylark, hare and field vole) and positive for partridge and the two invertebrate species. The feedback scenarios showed that the incorporation of information from ecological system to the farmer decision-making affected both a trend in area cultivated with energy maize as well as the animal responses.Synthesis and applications. Fully coupling agent-based decision-making and environmental simulation allows a detailed representation and integration of both social and ecological components of agricultural systems at proper spatial and temporal scales as well as of dynamic feedbacks between the two systems. By employing easy to interpret measures of changes in abundance and spatial occupancy of animal species, the simulation results could inform and simplify decision-making on expected impacts of economy and policy regulations on wildlife.
      PubDate: 2017-11-09T23:50:48.053519-05:
      DOI: 10.1111/1365-2664.13024
       
  • Functional traits in cover crop mixtures: Biological nitrogen fixation and
           multifunctionality
    • Authors: Jennifer Blesh
      Abstract: Cover crop mixtures with complementary plant functional traits including biological nitrogen fixation (BNF) may supply nitrogen (N) to farm fields while simultaneously providing other ecosystem functions such as N retention and weed suppression (i.e., multifunctionality). Understanding variation in these relationships across farms can help advance trait-based research in agroecology and ecological approaches to nutrient management.This on-farm experiment explored the contributions of two- and three-species cover crop mixtures, which combined legumes, brassicas and cool season grasses, to ecosystem functions across a gradient of soil fertility levels driven by farm management history.I evaluated the predictions that functional trait diversity of the cover crops would explain variation in multifunctionality, and that legume biomass and BNF within mixtures would be inversely correlated with indicators of soil N availability from organic matter across the farm gradient.Ecosystem functions varied widely across farms. As expected, functional diversity was a significant predictor of multifunctionality, although the relationship was weak. Cover crop mixtures had significantly greater multifunctionality than a cereal rye monoculture, though not at the highest observed levels of each function, indicating trade-offs among functions. Linear regression models showed that legume biomass and BNF were negatively correlated with soil properties indicative of N availability from soil organic matter, whereas non-legume and weed biomass were positively correlated with other measures of soil fertility.Synthesis and applications. Cover crop mixtures can increase functional diversity within crop rotations. Designing mixtures with complementary plant traits may be particularly effective for increasing multifunctionality and agroecosystem sustainability. On-farm research to understand variation in biological nitrogen fixation, which is both a plant trait and a key ecosystem function, across heterogeneous soil conditions, can inform management of soil fertility based on ecological principles.
      PubDate: 2017-11-09T04:50:33.92651-05:0
      DOI: 10.1111/1365-2664.13011
       
  • Trait-based approaches for guiding the restoration of degraded
           agricultural landscapes in East Africa
    • Authors: Madelon Lohbeck; Leigh Winowiecki, Ermias Aynekulu, Clement Okia, Tor-Gunnar Vågen
      Abstract: Functional ecology provides a framework that can link vegetation characteristics of various land uses with ecosystem function. However, this application has been mostly limited to [semi-]natural systems and small spatial scales. Here, we apply functional ecology to five agricultural landscapes in Kenya, Uganda and Ethiopia, and ask to what extent vegetation characteristics contribute to soil functions that are key to farmers’ livelihoods.We used the Land Degradation Surveillance Framework (LDSF), a multi-scale assessment of land health. Each LDSF site is a 10 × 10 km landscape in which vegetation cover and erosion prevalence were measured, a tree inventory was carried out, and topsoil (0–20 cm) samples were collected for organic carbon (SOC) analysis in approximately 160 × 1,000 m2 plots. Land degradation is a recurring phenomenon across the five landscapes, indicated by high erosion prevalence (67%–99% of the plots were severely eroded). We used mixed models to assess if vegetation cover, above-ground woody biomass and the functional properties of woody vegetation (weighted-mean trait values, functional diversity [FD]) explain variation in SOC and erosion prevalence.We found that the vegetation cover and above-ground biomass had strong positive effects on soil health by increasing SOC and reducing soil erosion. After controlling for cover and biomass, we found additional marginal effects of functional properties where FD was positively associated with SOC and the abundance of invasive species was associated with higher soil erosion.Synthesis and applications. This work illustrates how functional ecology can provide much-needed evidence for designing strategies to restore degraded agricultural land and the ecosystem services on which farmers depend. We show that to ensure soil health, it is vital to avoid exposed soil, maintain or promote tree cover, while ensuring functional diversity of tree species, and to eradicate invasive species.
      PubDate: 2017-11-09T00:15:38.402905-05:
      DOI: 10.1111/1365-2664.13017
       
  • High Carbon Stock forests provide co-benefits for tropical biodiversity
    • Authors: Nicolas J. Deere; Gurutzeta Guillera-Arroita, Esther L. Baking, Henry Bernard, Marion Pfeifer, Glen Reynolds, Oliver R. Wearn, Zoe G. Davies, Matthew J. Struebig
      Abstract: Carbon-based policies provide powerful opportunities to unite tropical forest conservation with climate change mitigation. However, their effectiveness in delivering biodiversity co-benefits is dependent on high levels of biodiversity being found in high carbon areas. Previous studies have focussed solely on the co-benefits associated with Reducing Emissions from Deforestation and forest Degradation (REDD+) over large spatial scales, with few empirically testing carbon-biodiversity correlations at management unit scales appropriate to decision-makers. Yet, in development frontiers, where most biodiversity and carbon loss occurs, carbon-based policies are increasingly driven by commodity certification schemes, which are applied at the concession level.Working in a typical human-modified landscape in Southeast Asia, we examined the biodiversity value of land prioritised via application of REDD+ or the High Carbon Stock (HCS) approach, the emerging land-use planning tool for oil palm certification. Carbon stocks were estimated via low- and high-resolution datasets derived from global or local-level biomass. Mammalian species richness was predicted using hierarchical Bayesian multispecies occupancy models of camera-trap data from forest and oil palm habitats.At the community level, HCS forest supported comparable mammal diversity to control sites in continuous forest, while lower carbon strata exhibited reduced species occupancy.No association was found between species richness and carbon when the latter was estimated using coarse-resolution data. However, when using high-resolution, locally validated biomass data, diversity demonstrated positive relationships with carbon for threatened and disturbance-sensitive species, suggesting sensitivity of co-benefits to carbon data sources and the species considered.Policy implications. Our work confirms the potential for environmental certification and Reducing Emissions from Deforestation and forest Degradation to work in tandem with conservation to mitigate agricultural impacts on tropical forest carbon stocks and biodiversity. Successful implementation of both approaches could be used to direct development to low carbon, low biodiversity areas in tropical countries.
      PubDate: 2017-11-06T01:16:07.299519-05:
      DOI: 10.1111/1365-2664.13023
       
  • Nutritional functional trait diversity of crops in south-eastern Senegal
    • Authors: Stephen A. Wood
      Abstract: Ecological trait diversity metrics have been used to highlight the impacts of agriculture. Such metrics can also be used to include human nutrition—an important dimension of human well-being—into assessments of agroecosystem function and services. Although crop yield is a common agroecosystem metric, it does not capture the multiple ways in which agriculture impacts people and the environment.Given that nutrient composition of crops is a set of functional traits, I apply a suite of functional diversity metrics—functional divergence, richness, evenness and dispersion—to crop production data from south-eastern Senegal. I also propose a new nutritional diversity metric—potential nutrient adequacy—to assess nutritional outcomes of different agricultural systems.I demonstrate high variability in nutritional diversity and potential adequacy among households and administrative departments in south-eastern Senegal. I show that most households produce nutritionally similar crops, rather than crops with high nutritional diversity. As a result, most households currently do not produce enough nutrients to meet minimal nutritional requirements.Using a scenario approach, I show that intensifying yields of staple crops and diversifying production to include non-staples can increase nutritional production and the potential to meet nutritional needs. I further show that a combination of intensification and diversification is needed to meet the need for a diverse group of nutrients.Policy implications. I develop a new metric that indicates the potential for a food system to meet the nutritional requirements of a population. This tool will allow practitioners to assess the nutritional adequacy of a food system and to design food systems that optimize nutritional outcomes. Application of this metric to different production scenarios showed that combining yield intensification with crop diversification is important to meeting full nutritional targets for smallholder agriculture. There is a broader need for incorporating other social and socio-ecological traits into trait-based assessments of agroecosystems.
      PubDate: 2017-11-01T23:56:12.935635-05:
      DOI: 10.1111/1365-2664.13026
       
  • Reclamation strategies for mined forest soils and overstorey drive
           understorey vegetation
    • Authors: Han Y.H. Chen; Shekhar R. Biswas, Timothy M. Sobey, Brian W. Brassard, Samuel F. Bartels
      Abstract: Understorey vegetation accounts for the majority of plant diversity in boreal forest ecosystems and contributes to ecosystem functioning. In restoration of degraded forested ecosystems, however, understorey vegetation is often restored passively, contrasting to clear strategies such as informed species choice and site improvement intervention for overstorey vegetation. The choice of overstorey-centred restoration strategy may have important consequences for understorey vegetation.We examined the effects of substrate material, overstorey type and time since reclamation (age) on understorey vegetation following reclamation of oil sands mining in Alberta, Canada. We sampled cover, richness, evenness and composition of understorey vegetation at 94 sites of conifer, mixedwood and broadleaf overstorey types on three reclamation substrates (overburden, secondary overburden and tailings sand), with age ranging from 4 to 30 years.Total, woody and non-woody understorey cover and species richness were the highest on secondary overburden and the lowest on tailings sand, and total cover also decreased with age. Woody cover and richness were the highest under broadleaf overstorey, while non-woody cover and richness were the lowest under conifer overstorey. Overall species evenness was not significantly affected by substrate type, overstorey type or age, but woody evenness was the highest on secondary overburden and the lowest on tailings sand, and non-woody evenness showed overstorey-dependent responses to age. Species composition varied with substrate type, overstorey type and age. Indicator species analysis revealed that tailings sand with conifer overstorey favoured grasses, while overburden and secondary overburden supported a mix of grasses, forbs and shrubs.Synthesis and applications. Our study demonstrates that overstorey-centred reclamation strategies impact the abundance, diversity and composition of understorey plant communities following oil sands mining. Landforms constructed with secondary overburden substrates and revegetated with mixedwood or broadleaf tree species provide the most favourable habitats for understorey vegetation, while tailings sand provide a poor substrate for understorey species diversity and composition. We therefore recommend utilizing secondary overburden and overburden substrate material during landform construction, and employing revegetation prescriptions that target mixedwood and broadleaf overstorey types to promote productive and diverse understorey plant communities on the reclaimed landscape.
      PubDate: 2017-11-01T23:56:03.859717-05:
      DOI: 10.1111/1365-2664.13018
       
  • Novel application of explicit dynamics occupancy models to ongoing aquatic
           invasions
    • Authors: Adam J. Sepulveda
      Abstract: Identification of suitable habitats, where invasive species can establish, is an important step towards controlling their spread. Accurate identification is difficult for new or slow invaders because unoccupied habitats may be suitable, given enough time for dispersal, while occupied habitats may prove to be unsuitable for establishment.To identify the suitable habitat of a recent invader, I used an explicit dynamics occupancy modelling framework to evaluate habitat covariates related to successful and failed establishments of American Bullfrogs (Lithobates catesbeianus) within the Yellowstone River floodplain of Montana, USA, from 2012 to 2016.During this 5-year period, bullfrogs failed to establish at most sites they colonized. Bullfrog establishment was most likely to occur and least likely to fail at sites closest to human-modified ponds and lakes and those with emergent vegetation. These habitat covariates were generally associated with the presence of permanent water.Suitable habitat for bullfrog establishment is abundant in the Yellowstone River floodplain, although many sites with suitable habitat remain uncolonized. Thus, the maximum distribution of bullfrogs is much greater than their current distribution.Synthesis and applications. Focused control efforts on habitats with or proximate to permanent waters are most likely to reduce the potential for invasive bullfrog establishment and spread in the Yellowstone River. The novel application of explicit dynamics occupancy models is a useful and widely applicable tool for guiding management efforts towards those habitats where new or slow invaders are most likely to establish and persist.
      PubDate: 2017-10-31T05:21:01.444687-05:
      DOI: 10.1111/1365-2664.13002
       
  • Role of multiple invasion mechanisms and their interaction in regulating
           the population dynamics of an exotic tree
    • Authors: Raelene M. Crandall; Tiffany M. Knight
      Abstract: Understanding the mechanisms that allow exotic species to have rapid population growth is an important step in the process of controlling existing invasions and preventing future invasions. Several hypotheses have been proposed to explain why some exotic species become invasive, the most prominent of which focus on the roles of habitat disturbance, competitors and consumers. The magnitude and direction of each of these mechanisms on population dynamics observed in previous studies is quite variable. It is possible that some of this variation results from interactions between mechanisms.We examined all of these mechanisms and their interactions on the population dynamics of the Asian exotic tree Ailanthus altissima (Simaroubaceae) in fire-suppressed oak-hickory forests in Missouri, USA. We experimentally reduced herbivory (using insecticide), reduced interspecific competition (plant removals), and manipulated disturbance with prescribed fire. We projected the effects of these treatments and their interactions on population dynamics by parameterizing an integral projection model.The lowest population growth rate is found where fire is absent and biotic interactions are present. Fire increased population growth rate, likely through the suppression of interspecific competitors, since competitor removal treatments increased population growth rate in the absence but not presence of fire.These results indicate that biotic resistance from interspecific competitors, more so than consumers, is important for slowing the invasion of A. altissima. Furthermore, disturbances that weaken biotic interactions, such as fire, should be used with caution when restoring habitats invaded by A. altissima.Synthesis and applications. Examining the main and interactive effects of disturbance, competition and herbivory on the population dynamics of exotic species provides a comprehensive understanding of the role of these factors in the invasion process and provides guidance for exotic species management.
      PubDate: 2017-10-31T02:55:16.559146-05:
      DOI: 10.1111/1365-2664.13020
       
  • Trade-offs in the multi-use potential of managed boreal forests
    • Authors: Joachim Strengbom; E. Petter Axelsson, Tomas Lundmark, Annika Nordin
      Abstract: Implementing multi-use forest management to account for both commercial and non-commercial ecosystem services is gaining increased global recognition. Despite its spatial extent, and great economic and ecological values, few studies have evaluated the boreal forest and its management to assess the potential for simultaneous delivery of a suite of ecosystem services.Using data from a Swedish long-term experiment, this study explores how biodiversity of the ground vegetation and potential delivery of multiple ecosystem services (timber production, carbon [C] storage and non-timber forest products) are influenced by two common silvicultural practices (thinning, fertilization and their interaction).Diversity (diversity indices and species richness) of the ground vegetation was higher in thinned than in unthinned forest, a result attributable in part to six species of lichens that only occurred in thinned forest. In addition, supply of lichens for reindeer forage was three times higher in thinned forest. Fertilization negatively affected the lingonberry shrub (Vaccinium vitis-idaea). Timber production increased with fertilization, but decreased with thinning. The potential for C storage was highest in fertilized forests, which, apart from having the highest timber production, also supported the highest standing tree biomass.The silvicultural practices evaluated induced trade-offs among the ecosystem features studied as thinning increased biodiversity of the ground vegetation, production potential of wild berries and lichens, but reduced timber production and the potential for C storage. Fertilization had the opposite effect, promoting the potential for C storage at the expense of biodiversity and the ecosystem services delivered by the ground vegetation.Synthesis and applications. Increased multi-use potential is a common goal for forest management in many parts of the world. Our result shows that commonly used silvicultural practices can be used to determine the multi-use output, and might be applied to maintain, or even increase the multi-use potential of the boreal forest biome. Nevertheless, trade-offs among values were common, indicating that the multi-use potential will be limited at the site level. Allowing management objectives to vary across the landscape might, in such cases, be a preferable way to achieve high multi-use potential.
      PubDate: 2017-10-28T01:15:32.817556-05:
      DOI: 10.1111/1365-2664.13019
       
  • Human development and climate affect hibernation in a large carnivore with
           implications for human–carnivore conflicts
    • Authors: Heather E. Johnson; David L. Lewis, Tana L. Verzuh, Cody F. Wallace, Rebecca M. Much, Lyle K. Willmarth, Stewart W. Breck
      Abstract: Expanding human development and climate change are dramatically altering habitat conditions for wildlife. While the initial response of wildlife to changing environmental conditions is typically a shift in behaviour, little is known about the effects of these stressors on hibernation behaviour, an important life-history trait that can subsequently affect animal physiology, demography, interspecific interactions and human-wildlife interactions. Given future trajectories of land use and climate change, it is important that wildlife professionals understand how animals that hibernate are adapting to altered landscape conditions so that management activities can be appropriately tailored.We investigated the influence of human development and weather on hibernation in black bears (Ursus americanus), a species of high management concern, whose behaviour is strongly tied to natural food availability, anthropogenic foods around development and variation in annual weather conditions. Using GPS collar data from 131 den events of adult female bears (n = 51), we employed fine-scale, animal-specific habitat information to evaluate the relative and cumulative influence of natural food availability, anthropogenic food and weather on the start, duration and end of hibernation.We found that weather and food availability (both natural and human) additively shaped black bear hibernation behaviour. Of the habitat variables we examined, warmer temperatures were most strongly associated with denning chronology, reducing the duration of hibernation and expediting emergence in the spring. Bears appeared to respond to natural and anthropogenic foods similarly, as more natural foods, and greater use of human foods around development, both postponed hibernation in the fall and decreased its duration.Synthesis and applications. Warmer temperatures and use of anthropogenic food subsides additively reduced black bear hibernation, suggesting that future changes in climate and land use may further alter bear behaviour and increase the length of their active season. We speculate that longer active periods for bears will result in subsequent increases in human–bear conflicts and human-caused bear mortalities. These metrics are commonly used by wildlife agencies to index trends in bear populations, but have the potential to be misleading when bear behaviour dynamically adapts to changing environmental conditions, and should be substituted with reliable demographic methods.
      PubDate: 2017-10-24T01:15:29.403008-05:
      DOI: 10.1111/1365-2664.13021
       
  • The role of topography and plant functional traits in determining tropical
           reforestation success
    • Authors: Alexander W. Cheesman; Noel D. Preece, Penny Oosterzee, Peter D. Erskine, Lucas A. Cernusak
      Abstract: Early establishment and sapling growth is a key phase in ensuring cost-effective reforestation success in relation to biodiversity outcomes. Therefore, species selection must consider the interaction between plant functional traits and the often-challenging and heterogeneous biophysical environment of degraded landscapes.In this study, we examine how microtopography (slope) results in spatial heterogeneity of soil nutrients, especially phosphorus (P) in a degraded tropical pasture landscape in Queensland, Australia. We then explore how this small-scale heterogeneity influences the growth of two native tree species, Cardwellia (C.) sublimis (Proteaceae) and Flindersia (F.) brayleyana (Rutaceae), which differ in key nutrient-acquisition strategies.The proteaceous C. sublimis was found to be buffered from possible P limitation in degraded soils due to its effective P acquisition by cluster roots. In contrast to C. sublimis, which showed no difference in growth after 5 years across a range of soil conditions, F. brayleyana was found to be highly responsive to soil conditions with increased growth in low-slope, higher P availability areas. The ability of F. brayleyana to take advantage of high soil P levels, including the development of leaves with higher P concentrations, resulted in an apparent switch in competitive fitness between these two species across a landscape gradient.Synthesis and applications. In a detailed study of a landscape reforestation experiment in North Queensland, Australia, we demonstrate that site edaphic factors can vary within tens of metres due to topographic relief, and that species respond differently to these conditions. We therefore show the need to consider both the spatial heterogeneity of edaphic factors and the below-ground functional traits of potential reforestation species when planning reforestation programmes.
      PubDate: 2017-10-22T23:11:31.576188-05:
      DOI: 10.1111/1365-2664.12980
       
  • Habitat restoration benefits wild bees: A meta-analysis
    • Authors: Rebecca K. Tonietto; Daniel J. Larkin
      Abstract: Pollinator conservation is of increasing interest in the light of managed honeybee (Apis mellifera) declines, and declines in some species of wild bees. Much work has gone into understanding the effects of habitat enhancements in agricultural systems on wild bee abundance, richness and pollination services. However, the effects of ecological restoration targeting “natural” ecological endpoints (e.g. restoring former agricultural fields to historic vegetation types or improving degraded natural lands) on wild bees have received relatively little attention, despite their potential importance for countering habitat loss.We conducted a meta-analysis to evaluate the effects of ecological restoration on wild bee abundance and richness, focusing on unmanaged bee communities in lands restored and managed to increase habitat availability and quality. Specifically, we assessed bee abundance and/or richness across studies comparing restored vs. unrestored treatments and studies investigating effects of specific habitat restoration techniques, such as burning, grazing, invasive plant removal and seeding.We analysed 28 studies that met our selection criteria: these represented 11 habitat types and 7 restoration techniques. Nearly all restorations associated with these studies were performed without explicit consideration of habitat needs for bees or other pollinators. The majority of restorations targeted plant community goals, which could potentially have ancillary benefits for bees.Restoration had overall positive effects on wild bee abundance and richness across multiple habitat types. Specific restoration actions, tested independently, also tended to have positive effects on wild bee richness and abundance.Synthesis and applications. We found strong evidence that ecological restoration advances wild bee conservation. This is important given that habitat loss is recognized as a leading factor in pollinator decline. Pollinator responses to land management are rarely evaluated in non-agricultural settings and so support for wild bees may be an underappreciated benefit of botanically focused management. Future restoration projects that explicitly consider the needs of wild bees could be more effective at providing nesting, foraging and other habitat resources. We encourage land managers to design and evaluate restoration projects with the habitat needs of wild bee species in mind.
      PubDate: 2017-10-22T23:10:45.848727-05:
      DOI: 10.1111/1365-2664.13012
       
  • Linking spring phenology with mechanistic models of host movement to
           predict disease transmission risk
    • Authors: Jerod A. Merkle; Paul C. Cross, Brandon M. Scurlock, Eric K. Cole, Alyson B. Courtemanch, Sarah R. Dewey, Matthew J. Kauffman
      Abstract: Disease models typically focus on temporal dynamics of infection, while often neglecting environmental processes that determine host movement. In many systems, however, temporal disease dynamics may be slow compared to the scale at which environmental conditions alter host space-use and accelerate disease transmission.Using a mechanistic movement modelling approach, we made space-use predictions of a mobile host (elk [Cervus Canadensis] carrying the bacterial disease brucellosis) under environmental conditions that change daily and annually (e.g., plant phenology, snow depth), and we used these predictions to infer how spring phenology influences the risk of brucellosis transmission from elk (through aborted foetuses) to livestock in the Greater Yellowstone Ecosystem.Using data from 288 female elk monitored with GPS collars, we fit step selection functions (SSFs) during the spring abortion season and then implemented a master equation approach to translate SSFs into predictions of daily elk distribution for five plausible winter weather scenarios (from a heavy snow, to an extreme winter drought year). We predicted abortion events by combining elk distributions with empirical estimates of daily abortion rates, spatially varying elk seroprevelance and elk population counts.Our results reveal strong spatial variation in disease transmission risk at daily and annual scales that is strongly governed by variation in host movement in response to spring phenology. For example, in comparison with an average snow year, years with early snowmelt are predicted to have 64% of the abortions occurring on feedgrounds shift to occurring on mainly public lands, and to a lesser extent on private lands.Synthesis and applications. Linking mechanistic models of host movement with disease dynamics leads to a novel bridge between movement and disease ecology. Our analysis framework offers new avenues for predicting disease spread, while providing managers tools to proactively mitigate risks posed by mobile disease hosts. More broadly, we demonstrate how mechanistic movement models can provide predictions of ecological conditions that are consistent with climate change but may be more extreme than has been observed historically.
      PubDate: 2017-10-19T19:01:02.02426-05:0
      DOI: 10.1111/1365-2664.13022
       
  • Nest survival modelling using a multi-species approach in forests managed
           for timber and biofuel feedstock
    • Authors: Zachary G. Loman; Adrian P. Monroe, Samuel K. Riffell, Darren A. Miller, Francisco J. Vilella, Bradley R. Wheat, Scott A. Rush, James A. Martin
      Abstract: Switchgrass (Panicum virgatum) intercropping is a novel forest management practice for biomass production intended to generate cellulosic feedstocks within intensively managed loblolly pine-dominated landscapes. These pine plantations are important for early-successional bird species, as short rotation times continually maintain early-successional habitat. We tested the efficacy of using community models compared to individual surrogate species models in understanding influences on nest survival. We analysed nest data to test for differences in habitat use for 14 bird species in plots managed for switchgrass intercropping and controls within loblolly pine (Pinus taeda) plantations in Mississippi, USA.We adapted hierarchical models using hyper-parameters to incorporate information from both common and rare species to understand community-level nest survival. This approach incorporates rare species that are often discarded due to low sample sizes, but can inform community-level demographic parameter estimates. We illustrate use of this approach in generating both species-level and community-wide estimates of daily survival rates for songbird nests. We were able to include rare species with low sample size (minimum n = 5) to inform a hyper-prior, allowing us to estimate effects of covariates on daily survival at the community level, then compare this with a single-species approach using surrogate species. Using single-species models, we were unable to generate estimates below a sample size of 21 nests per species.Community model species-level survival and parameter estimates were similar to those generated by five single-species models, with improved precision in community model parameters.Covariates of nest placement indicated that switchgrass at the nest site (
      PubDate: 2017-10-19T03:15:49.325761-05:
      DOI: 10.1111/1365-2664.13015
       
  • Reef accessibility impairs the protection of sharks
    • Authors: Jean-Baptiste Juhel; Laurent Vigliola, David Mouillot, Michel Kulbicki, Tom B. Letessier, Jessica J. Meeuwig, Laurent Wantiez
      Abstract: Reef sharks are declining world-wide under ever-increasing fishing pressure, with potential consequences on ecosystem functioning. Marine protected areas (MPAs) are currently one of the management tools used to counteract the pervasive impacts of fishing. However, MPAs in which reef sharks are abundant tend to be located in remote and underexploited areas, preventing a fair assessment of management effectiveness beyond remoteness from human activities.Here, we determine the conditions under which MPAs can effectively protect sharks along a wide gradient of reef accessibility, from the vicinity of a regional capital towards remote areas, using 385 records from baited remote underwater video systems and 2,790 underwater visual censuses performed in areas open to fishing and inside 15 MPAs across New Caledonia (South-Western Pacific).We show that even one of the world's oldest (43 years), largest (172 km2) and most restrictive (no-entry) MPA (Merlet reserve) on coral reefs has between 17.3% and 45.3% fewer shark species and between 37.2% and 79.8% fewer shark abundance than remote areas in a context where sharks are not historically exploited.On coral reefs situated at less than 1 hr of travel time from humans, shark populations are so low in abundance (less than 0.05 individuals per 1,000 m2) that their functional roles are severely limited.Synthesis and applications. Remote areas are the last sanctuaries for reef sharks, providing a new baseline from which to evaluate human impacts on the species. However, there is no equivalent close to human activities even in large, old and strongly restrictive marine protected areas. As such sharks deserve strong protection efforts. The large, no-entry marine protected areas, close to humans, offer limited benefits for reef shark populations, but provide more realistic conservation targets for managers of human-dominated reefs. The exclusion of human activities on a sufficiently large area is key to protect reef shark populations. However, this strategy remains difficult to apply in many countries critically depending on reef resources for food security or livelihood.
      PubDate: 2017-10-17T19:01:02.112318-05:
      DOI: 10.1111/1365-2664.13007
       
  • Reintroducing endangered raptors: A case study of supplementary feeding
           and removal of nestlings from wild populations
    • Authors: Miguel Ferrer; Virginia Morandini, Gerardo Baguena, Ian Newton
      Abstract: Supplementary feeding is a common practice to raise reproductive output in raptors and other species; nevertheless, its application in conservation has only recently been discussed critically. Here, we analyse the effect of supplementary feeding in territorial raptors, taking advantage of two long-term datasets for the Spanish imperial eagle (Aquila adalberti) and bearded vulture (Gypaetus barbatus). In both species, supplementary feeding was used over four years, allowing the extraction of eggs or nestlings for reintroduction programmes.Both populations increased during the last 20 years. In 2001, only 10 Spanish imperial eagle pairs were found in Sierra Morena, increasing to 91 pairs in 2015 (810% of increase). The Bearded vulture population in Aragon increased from 15 occupied territories in 1988 to 67 in 2012 (347% of increase). Density-dependent breeding productivity on habitat heterogeneity was established in both populations.Results of generalized linear mixed model analysis with relative productivity as the dependent variable, species and supplementary feeding as fixed factors, and territory as random factor showed a significant effect of supplementary feeding on relative productivity in both species as well as in the interaction between territory and supplementary feeding. This implied a different response among territories to supplementary feeding. Birds in poor-quality territories with low productivity levels responded more strongly to supplementary feeding than birds in territories with higher levels of natural productivity.A reintroduction programme based on supplementary feeding and extraction of nestlings costs eight times less than the same programme based on captive breeding and takes 10 years less.Synthesis and applications. Supplementary feeding in territorial raptors could be useful (1) in an episodic main prey collapse and (2) in poor-quality territories in a high-density population, to produce extra young for reintroduction programmes. For greatest efficiency, supplementary feeding needs to be targeted at poorer territories in which the reproductive rate has the potential to be raised by provision of extra food. The extra young produced can then be used in reintroduction programmes in which chances of recruiting to a breeding population are high.
      PubDate: 2017-10-17T07:05:41.509549-05:
      DOI: 10.1111/1365-2664.13014
       
  • Restoration of native mangrove wetlands can reverse diet shifts of benthic
           macrofauna caused by invasive cordgrass
    • Authors: Jianxiang Feng; Qian Huang, Hui Chen, Jiemin Guo, Guanghui Lin
      Abstract: Ecological replacement using native mangrove species combined with physical treatments has become an effective method in controlling the spread of invasive cordgrass Spartina alterniflora. To re-establish ecosystem functions, trophic interactions between macrofauna and their potential food resources must be considered during the restoration process.Here, we examined the changes in the diets of macrofauna in three restored mangrove ecosystems with different invasion histories following the removal of S. alterniflora in southern China. Carbon and nitrogen stable isotope ratios for dominant macrofauna, as well as their potential food sources, were analysed. The relative contributions of the different carbon sources to the diets of benthic macrofauna and isotopic niche width, including convex hull areas and standard ellipse areas of the macrofaunal community, were then calculated and compared among sampling sites in each region.Our results indicated that Spartina-derived detritus contributed to>80% of the organic carbon sources of dominant macrofauna in the S. alterniflora communities in all three regions. Spartina alterniflora communities had lower convex hull areas and standard ellipse areas than natural mangrove forests, indicating significant resource competition among different consumer populations. Replacing S. alterniflora with the native mangrove species Kandelia obovata could reverse the diets of these macrofaunal species, resulting in a shift from homogeneous Spartina-dominated diets to more heterogeneous algae-based diets. It could take several decades to restore food web interactions to a pre-impacted state. Even the diets of macrofauna in mature mangrove (>40 years) remained affected by the Spartina-derived organic matter.Synthesis and applications. Our study reveals that the ecological replacement of invasive Spartina alterniflora using native mangrove species could restore food web function gradually. However, this removal and replacement approach is a long process and requires significant manpower and resources. Furthermore, the native ecosystem will continue to be influenced by the cordgrass as long as large areas of wetland nearby are occupied by S. alterniflora. Consequently, preventing the colonization of S. alterniflora should be a priority for coastal ecosystem management in southern China.
      PubDate: 2017-10-15T23:10:36.393706-05:
      DOI: 10.1111/1365-2664.12987
       
  • Ecosystem services and disservices provided by small rodents in arable
           fields: Effects of local and landscape management
    • Authors: Christina Fischer; Christoph Gayer, Kornélia Kurucz, Friederike Riesch, Teja Tscharntke, Péter Batáry
      Abstract: In agriculture, both valuable ecosystem services and unwanted ecosystem disservices can be produced by the same organism group. For example, small rodents can provide biological control through weed seed consumption but may also act as pests, causing crop damage.We studied the hypothesized causal relationships between ecosystem services (removal of weed seeds) and disservices (removal of wheat grains and crop damage) derived by small rodents (voles and mice) at multiple spatial scales. At the landscape scale, we studied the effects of landscape compositional and configurational heterogeneity on the abundance of voles and mice and their related ecosystem services and disservices along the former inner German border in east and west Germany. At the local scale, we studied how abundance and ecosystem functions are affected by management intensity (organic vs. conventional winter wheat), associated differences in crop characteristics and edge effects.Linear mixed-effects models and path analysis show that voles drove ecosystem disservices, but not ecosystem services, in agricultural fields. Daily wheat seed removal by voles was influenced by increasing wheat height and was almost three times higher than weed seed removal, which was not related to local- or landscape-scale effects.Abundance of voles and associated crop damage decreased with lower crop density and higher wheat height, which were associated with organic farming. Abundance of voles and crop damage were highest in conventional fields in west Germany.Synthesis and applications. As the ecosystem disservice of wheat seed consumption by small rodents must be considered mainly during crop sowing, management before crop harvest should focus on decreasing the pest potential of voles but not mice. Our results suggest that densities of voles and their ecosystem disservices could be reduced by having fields with low crop density and high wheat height, practices associated with organic farming. Surrounding landscapes with low compositional and configurational heterogeneity could further reduce voles’ pest potential, but with probable negative effects on farmland biodiversity.
      PubDate: 2017-10-15T23:10:30.478586-05:
      DOI: 10.1111/1365-2664.13016
       
  • Rodent, snake and raptor use of restored native perennial grasslands is
           lower than use of unrestored exotic annual grasslands
    • Authors: Kristina M. Wolf; Matthew A. Whalen, Ryan P. Bourbour, Roger A. Baldwin
      Abstract: In California's Central Valley, most native grasslands have been destroyed or degraded due to invasion, farming and development. Grassland restoration is often assumed to provide improved wildlife habitat, ostensibly increasing the abundance and diversity of at least some native wildlife species relative to unrestored, invaded annual grasslands.We compared rodent, snake and raptor activity and species richness at paired unrestored and restored grasslands across four blocked locations in the Central Valley using trapping and observational surveys in up to four seasons per guild from 2014 to 2015. Restored treatments were planted with native perennial grasses 13–24 years prior to study initiation but were partially re-invaded by Mediterranean annual grasses and forbs. Unrestored treatments contained similar non-native plant species assemblages as restored treatments, but did not contain any native grass.Rodent, snake and raptor activity was generally higher in unrestored relative to restored treatments. For rodents, the non-native Mus musculus (house mouse) showed the greatest disparity in abundance, while greater raptors and snakes likely responded to greater rodent abundance.Within treatments, species-specific rodent responses were related to structure of physical vegetation. In particular, Peromyscus maniculatus (native deer mouse) was associated with more bare ground and shorter vegetation, while the house mouse was associated with less bare ground and taller vegetation, regardless of treatment type. Substantial changes in rodent species composition were observed over short periods of time (
      PubDate: 2017-10-11T23:20:37.374141-05:
      DOI: 10.1111/1365-2664.12990
       
  • Quantifying the attractiveness of broad-spectrum street lights to aerial
           nocturnal insects
    • Authors: Andrew Wakefield; Moth Broyles, Emma L. Stone, Stephen Harris, Gareth Jones
      Abstract: Sodium street lights, dominated by long wavelengths of light, are being replaced by broad-spectrum, white lights globally, in particular light-emitting diodes (LEDs). These white lights typically require less energy to operate and are therefore considered “eco-friendly”. However, little attention has been paid to the impacts white lights may have upon local wildlife populations.We compared insect attraction to orange (high-pressure sodium, HPS) and white (metal halide, MH and LED) street lights experimentally using portable street lights and custom-made flight intercept traps.Significantly more (greater than five times as many) insects were attracted to white MH street lights than white (4,250 K) LED and HPS lights. There was no statistical difference in the numbers of insects attracted to LED and HPS lights for most taxa caught. However, rarefaction shows a greater diversity of insects caught at LED than HPS lights.Policy implications. With the current, large-scale conversion to white light-emitting diode (LED) lighting, our results give insight into how changes to street light technology may affect wildlife populations and communities. We recommend avoiding metal halide light installations as they attract many more insects than competing technologies. We highlight the need to tailor LED lighting to prevent disturbances across multiple insect taxa.
      PubDate: 2017-10-08T23:50:32.350783-05:
      DOI: 10.1111/1365-2664.13004
       
  • Assessing the sensitivity of biodiversity indices used to inform fire
           management
    • Authors: Katherine M. Giljohann; Luke T. Kelly, Jemima Connell, Michael F. Clarke, Rohan H. Clarke, Tracey J. Regan, Michael A. McCarthy
      Abstract: Biodiversity indices are widely used to summarize changes in the distribution and abundance of multiple species and measure progress towards management targets. However, the sensitivity of biodiversity indices to the data, landscape classification and conservation values underpinning them are rarely interrogated. There are limited studies to help scientists and land managers use biodiversity indices in the presence of fire and vegetation succession.The geometric mean of species' relative abundance or occurrence (G) is a biodiversity index that can be used to determine the mix of post-fire vegetation that maximizes biodiversity. We explored the sensitivity of G to (1) type of biodiversity data, (2) representation of ecosystem states, (3) expression of conservation values, and (4) uncertainty in species' response to landscape structure. Our case study is an area of fire-prone woodland in southern Australia where G is used in fire management planning. We analysed three datasets to determine the fire responses of 170 bird, mammal and reptile species.G and fire management targets were sensitive to the species included in the analysis. The optimal mix of vegetation successional states for threatened birds was more narrowly defined than the optimal mix for all species combined. G was less sensitive to successional classification (i.e. number of states); although classifications of increasing complexity provided additional insights into desirable levels of heterogeneity.Weighting species by conservation status or endemism influenced the mix of vegetation states that maximized biodiversity. When a higher value was placed on threatened species the importance of late successional vegetation was emphasized.Representing variation in individual species' response to vegetation structure made it clearer when a decrease in G was likely to reflect a significant reduction in species occurrences.Synthesis and applications. Data, models and conservation values can be combined using biodiversity indices to make robust environmental decisions. Combining different types of biodiversity data using composite indices, such as the geometric mean, can improve the coverage and relevance of biodiversity indices. We recommend that evaluation of biodiversity indices for fire management verify how index assumptions align with management objectives, consider the relative merits of different types of biodiversity data, test sensitivity of ecosystem state definitions and incorporate conservation values through species weightings.
      PubDate: 2017-10-04T05:30:36.451917-05:
      DOI: 10.1111/1365-2664.13006
       
  • Tiny niches and translocations: The challenge of identifying suitable
           recipient sites for small and immobile species
    • Authors: Rob W. Brooker; Mark J. Brewer, Andrea J. Britton, Antonia Eastwood, Christopher Ellis, Alessandro Gimona, Laura Poggio, David R. Genney
      Abstract: Assisted colonisation, one form of species translocation, has been proposed as a tool for helping species to track suitable conditions in a changing climate. There are considerable practical challenges associated with it, including predicting where to place translocated individuals. This problem may be particularly big for small and immobile species, where small-scale microenvironmental conditions de-couple them from environmental conditions as projected in large-scale climate models.To investigate this problem, we developed a survey-based model to predict the occurrence of our target species, the fruticose terricolous arctic-alpine lichen, Flavocetraria nivalis, within the Cairngorm Mountains.We then undertook an experimental translocation of this species. A second model, using variables that were significant in the survey-based model, was only fair at predicting the initial pattern of survival at the recipient site.However, model fit of the translocation survival model improved over time as the distribution of surviving individuals more accurately reflected the distribution of suitable environmental conditions. In addition, model predictive power increased with the addition of data on microclimatic conditions at recipient plots.Synthesis and applications. Our results demonstrate that, for species which respond strongly to local environmental conditions, are immobile and, to some extent, decoupled from larger scale climates, it may be difficult to build a priori accurate predictive models of habitat suitability. In these cases, a combination of modelling and expert judgement, along with the movement of substantial numbers of transplants, may be the appropriate options for maximising the success of assisted colonisation.
      PubDate: 2017-10-03T01:20:27.363709-05:
      DOI: 10.1111/1365-2664.13008
       
  • A prioritised list of invasive alien species to assist the effective
           implementation of EU legislation
    • Authors: Carles Carboneras; Piero Genovesi, Montserrat Vilà, Tim M. Blackburn, Martina Carrete, Miguel Clavero, Bram D'hondt, Jorge F. Orueta, Belinda Gallardo, Pedro Geraldes, Pablo González-Moreno, Richard D. Gregory, Wolfgang Nentwig, Jean-Yves Paquet, Petr Pyšek, Wolfgang Rabitsch, Iván Ramírez, Riccardo Scalera, José L. Tella, Paul Walton, Robin Wynde
      Abstract: Effective prevention and control of invasive species generally relies on a comprehensive, coherent and representative list of species that enables resources to be used optimally. European Union (EU) Regulation 1143/2014 on invasive alien species (IAS) aims to control or eradicate priority species, and to manage pathways to prevent the introduction and establishment of new IAS; it applies to species considered of Union concern and subject to formal risk assessment. So far, 49 species have been listed but the criteria for selecting species for risk assessment have not been disclosed and were probably unsystematic.We developed a simple method to systematically rank IAS according to their maximum potential threat to biodiversity in the EU. We identified 1,323 species as potential candidates for listing, and evaluated them against their invasion stages and reported impacts, using information from databases and scientific literature.900 species fitted the criteria for listing according to IAS Regulation. We prioritised 207 species for urgent risk assessment, 59 by 2018 and 148 by 2020, based on their potential to permanently damage native species or ecosystems; another 336 species were identified for a second phase (by 2025), to prevent or reverse their profound impacts on biodiversity; and a further 357 species for assessment by 2030.Policy implications. We propose a systematic, proactive approach to selecting and prioritising IAS for risk assessment to assist European Union policy implementation. We assess an unprecedented number of species with potential to harm EU biodiversity using a simple methodology and recommend which species should be considered for risk assessment in a ranked order of priority along the timeline 2018–2030, based on their maximum reported impact and their invasion history in Europe.
      PubDate: 2017-10-03T01:00:34.358159-05:
      DOI: 10.1111/1365-2664.12997
       
  • Corrigendum
    • PubDate: 2017-09-28T04:52:07.115004-05:
      DOI: 10.1111/1365-2664.13009
       
  • Weed suppression greatly increased by plant diversity in intensively
           managed grasslands: A continental-scale experiment
    • Authors: John Connolly; Maria-Teresa Sebastià, Laura Kirwan, John Anthony Finn, Rosa Llurba, Matthias Suter, Rosemary P. Collins, Claudio Porqueddu, Áslaug Helgadóttir, Ole H. Baadshaug, Gilles Bélanger, Alistair Black, Caroline Brophy, Jure Čop, Sigridur Dalmannsdóttir, Ignacio Delgado, Anjo Elgersma, Michael Fothergill, Bodil E. Frankow-Lindberg, An Ghesquiere, Piotr Golinski, Philippe Grieu, Anne-Maj Gustavsson, Mats Höglind, Olivier Huguenin-Elie, Marit Jørgensen, Zydre Kadziuliene, Tor Lunnan, Paivi Nykanen-Kurki, Angela Ribas, Friedhelm Taube, Ulrich Thumm, Alex De Vliegher, Andreas Lüscher
      Abstract: Grassland diversity can support sustainable intensification of grassland production through increased yields, reduced inputs and limited weed invasion. We report the effects of diversity on weed suppression from 3 years of a 31-site continental-scale field experiment.At each site, 15 grassland communities comprising four monocultures and 11 four-species mixtures based on a wide range of species' proportions were sown at two densities and managed by cutting. Forage species were selected according to two crossed functional traits, “method of nitrogen acquisition” and “pattern of temporal development”.Across sites, years and sown densities, annual weed biomass in mixtures and monocultures was 0.5 and 2.0 t  DM ha−1 (7% and 33% of total biomass respectively). Over 95% of mixtures had weed biomass lower than the average of monocultures, and in two-thirds of cases, lower than in the most suppressive monoculture (transgressive suppression). Suppression was significantly transgressive for 58% of site-years. Transgressive suppression by mixtures was maintained across years, independent of site productivity.Based on models, average weed biomass in mixture over the whole experiment was 52% less (95% confidence interval: 30%–75%) than in the most suppressive monoculture. Transgressive suppression of weed biomass was significant at each year across all mixtures and for each mixture.Weed biomass was consistently low across all mixtures and years and was in some cases significantly but not largely different from that in the equiproportional mixture. The average variability (standard deviation) of annual weed biomass within a site was much lower for mixtures (0.42) than for monocultures (1.77).Synthesis and applications. Weed invasion can be diminished through a combination of forage species selected for complementarity and persistence traits in systems designed to reduce reliance on fertiliser nitrogen. In this study, effects of diversity on weed suppression were consistently strong across mixtures varying widely in species' proportions and over time. The level of weed biomass did not vary greatly across mixtures varying widely in proportions of sown species. These diversity benefits in intensively managed grasslands are relevant for the sustainable intensification of agriculture and, importantly, are achievable through practical farm-scale actions.
      PubDate: 2017-09-27T00:05:51.421092-05:
      DOI: 10.1111/1365-2664.12991
       
  • A revised trait-based framework for agroecosystems including decision
           rules
    • Authors: Gaëlle Damour; Marie L. Navas, Eric Garnier
      Abstract: Designing agroecological cropping systems, which have enhanced biodiversity and that improve agroecosystem services, is recognized as the most likely method of improving the environmental sustainability of agriculture. However, tools and methods for designing such systems are lacking.To help to fill this gap, we propose a revised trait-based response/effect framework as applied to agroecosystems, which takes into account farmers’ decision rules.The framework consists of a “Biophysical module”, which describes the biophysical functioning of the agroecosystem on a response/effect traits basis and a “Decision module”, which encompasses the farmer's choices that follow decision rules, to account for the high degree of human control of filters and community structure operating in cultivated systems.The introduction of the Decision module and its interactions with the Biophysical module opens new research priorities related to trade-offs between services, to species choice and to the relationships between the community composition, functional structure and the functions.Synthesis and applications. We proposed a revised trait-based response/effect framework as applied to agroecosystems, which incorporates farmers’ decisions. This framework has great potential to address questions related to the strategic choices associated with multispecies cropping system design, from plant (species choices) to community (optimization of community composition) scales. It also contributes to improving the rationale to manage multifunctional agroecosystems, which extend beyond yield alone, by enabling the exploration of trade-offs between ecosystem services.
      PubDate: 2017-09-25T00:25:25.938439-05:
      DOI: 10.1111/1365-2664.12986
       
  • Spatial mismatch between management units and movement ecology of a
           partially migratory ungulate
    • Authors: Erling L. Meisingset; Leif E. Loe, Øystein Brekkum, Richard Bischof, Inger M. Rivrud, Unni S. Lande, Barbara Zimmermann, Vebjørn Veiberg, Atle Mysterud
      Abstract: Population-level management is difficult to achieve if wildlife routinely crosses administrative boundaries, as is particularly frequent for migratory populations. However, the degree of mismatch between management units and scales at which ecological processes operate has rarely been quantified. Such insight is vital for delimiting functional population units of partially migratory species common in northern forest ecosystems.We combined an extensive dataset of 412 GPS-marked red deer (Cervus elaphus) across Norway with information on the size and borders of two administrative levels, the governmental level (municipality) and landowner level (local management units, LMUs), to determine the timing and scale of mismatch between animal space use and management units. We analysed how landscape characteristics affected the use of management units and the timing and likelihood of crossing borders between them, in an effort to delineate more appropriate units in various landscapes.Median municipality size could potentially cover 70% of female and 62% of male annual ranges, while only 12% and 4% of LMUs were expansive enough to accommodate migratory routes in females and males, respectively. Red deer migrate along elevational gradients and are more likely to find both suitable lowland winter habitat and higher summer habitat within management units with variable topography. Consistent with this, the likelihood of border crossing decreased with increasing diversity of elevations.Synthesis and applications. We demonstrate a considerable mismatch between animal space use and management units. Far-ranging movements and frequent administrative border crossings during autumn migration coincides with the period of active management (hunting season). Our study also highlights that, due to extensive movements of males, coordination of management aims may provide a more realistic avenue than increasing sizes of local management units. A more general insight is that the degree of mismatch between range use and management units depends on the season and landscape type. This needs to be accounted for when delimitating functional population units of migratory populations.
      PubDate: 2017-09-24T23:46:11.929669-05:
      DOI: 10.1111/1365-2664.13003
       
  • On the extinction of the single-authored paper: The causes and
           consequences of increasingly collaborative applied ecological research
    • Authors: Jos Barlow; Philip A. Stephens, Michael Bode, Marc W. Cadotte, Kirsty Lucas, Erika Newton, Martin A. Nuñez, Nathalie Pettorelli
      Pages: 1 - 4
      PubDate: 2017-12-11T01:13:26.996586-05:
      DOI: 10.1111/1365-2664.13040
       
  • Functional traits in agroecology: Advancing description and prediction in
           agroecosystems
    • Authors: Adam R. Martin; Marney E. Isaac
      Pages: 5 - 11
      PubDate: 2017-12-11T01:13:30.539809-05:
      DOI: 10.1111/1365-2664.13039
       
  • Integrating invasive species policies across ornamental horticulture
           supply chains to prevent plant invasions
    • Authors: Philip E. Hulme; Giuseppe Brundu, Marta Carboni, Katharina Dehnen-Schmutz, Stefan Dullinger, Regan Early, Franz Essl, Pablo González-Moreno, Quentin J. Groom, Christoph Kueffer, Ingolf Kühn, Noëlie Maurel, Ana Novoa, Jan Pergl, Petr Pyšek, Hanno Seebens, Rob Tanner, Julia M. Touza, Mark Kleunen, Laura N.H. Verbrugge
      Pages: 92 - 98
      Abstract: Ornamental horticulture is the primary pathway for invasive alien plant introductions. We critically appraise published evidence on the effectiveness of four policy instruments that tackle invasions along the horticulture supply chain: pre-border import restrictions, post-border bans, industry codes of conduct and consumer education.Effective pre-border interventions rely on rigorous risk assessment and high industry compliance. Post-border sales bans become progressively less effective when alien species become widespread in a region.A lack of independent performance evaluation and of public disclosure, limits the uptake and effectiveness of voluntary codes of conduct and discourages shifts in consumer preference away from invasive alien species.Policy implications. Closing the plant invasion pathway associated with ornamental horticulture requires government-industry agreements to fund effective pre- and post-border weed risk assessments that can be subsequently supported by widely adopted, as well as verifiable, industry codes of conduct. This will ensure producers and consumers make informed choices in the face of better targeted public education addressing plant invasions.
      PubDate: 2017-07-18T03:40:24.63959-05:0
      DOI: 10.1111/1365-2664.12953
       
  • Are ranger patrols effective in reducing poaching-related threats within
           protected areas'
    • Authors: Jennifer F. Moore; Felix Mulindahabi, Michel K. Masozera, James D. Nichols, James E. Hines, Ezechiel Turikunkiko, Madan K. Oli
      Pages: 99 - 107
      Abstract: Poaching is one of the greatest threats to wildlife conservation world-wide. However, the spatial and temporal patterns of poaching activities within protected areas, and the effectiveness of ranger patrols and ranger posts in mitigating these threats, are relatively unknown.We used 10 years (2006–2015) of ranger-based monitoring data and dynamic multi-season occupancy models to quantify poaching-related threats, to examine factors influencing the spatio-temporal dynamics of these threats and to test the efficiency of management actions to combat poaching in Nyungwe National Park (NNP), Rwanda.The probability of occurrence of poaching-related threats was highest at lower elevations (1,801–2,200 m), especially in areas that were close to roads and tourist trails; conversely, occurrence probability was lowest at high elevation sites (2,601–3,000 m), and near the park boundary and ranger posts. The number of ranger patrols substantially increased the probability that poaching-related threats disappear at a site if threats were originally present (i.e. probability of extinction of threats). Without ranger visits, the annual probability of extinction of poaching-related threats was an estimated 7%; this probability would increase to 20% and 57% with 20 and 50 ranger visits per year, respectively.Our results suggest that poaching-related threats can be effectively reduced in NNP by adding ranger posts in areas where they do not currently exist, and by increasing the number of patrols to sites where the probability of poaching activities is high.Synthesis and applications. Our application of dynamic occupancy models to predict the probability of presence of poaching-related threats is novel, and explicitly considers imperfect detection of illegal activities. Based on the modelled relationships, we identify areas that are most vulnerable to poaching, and offer insights regarding how ranger patrols can be optimally deployed to reduce poaching-related threats and other illegal activites, while taking into account potential sampling biases. We show that poaching can be effectively reduced by increasing ranger patrols to areas under high risk of poaching activities, and by adding ranger patrols near these sites. These findings are broadly applicable to national parks and protected areas experiencing a high degree of poaching and other illegal activities.
      PubDate: 2017-08-02T23:06:07.849294-05:
      DOI: 10.1111/1365-2664.12965
       
  • Defining and classifying migratory habitats as sources and sinks: The
           migratory pathway approach
    • Authors: Richard A. Erickson; Jay E. Diffendorfer, D. Ryan Norris, Joanna A. Bieri, Julia E. Earl, Paula Federico, John M. Fryxell, Kevin R. Long, Brady J. Mattsson, Christine Sample, Ruscena Wiederholt, Wayne E. Thogmartin
      Pages: 108 - 117
      Abstract: Understanding and conserving migratory species requires a method for characterizing the seasonal flow of animals among habitats. Source-sink theory describes the metapopulation dynamics of species by classifying habitats as population sources (i.e. net contributors) or sinks (i.e. net substractors). Migratory species may have non-breeding habitats important to the species (e.g. overwintering or stopover habitats) that traditional source-sink theory would classify as sinks because these habitats produce no individuals. Conversely, existing migratory network models can evaluate the relative contribution of non-breeding nodes, but these models make an equilibrium assumption that is difficult to meet when examining real migratory populations.We extend a pathway-based metric allowing breeding habitats, non-breeding habitats and migratory pathways connecting these habitats to be classified as sources or sinks. Rather than being based on whether place- or season-specific births exceed deaths, our approach quantifies the total demographic contribution from a node or migratory pathway over a flexibly defined yet limited time period across an organism's life cycle. As such, it provides a snapshot of a migratory system and therefore does not require assumptions associated with equilibrium dynamics.We first develop a generalizable mathematical notation and then demonstrate how the metric may be used with two case studies: the common loon (Gavia immer) and Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri). These examples highlight how stressors can impact stopover and wintering habitats (loons) and habitat management targeting migratory pathways can improve population status (trout).Synthesis and applications. Each of the two case studies presented describes how effects at one location are felt by populations in another through the seasonal flow of individuals. The contribution metric we present should be helpful in allocating regulatory and management attention to times and locations most critical to migratory species persistence.
      PubDate: 2017-07-14T01:16:09.018839-05:
      DOI: 10.1111/1365-2664.12952
       
  • Conservation benefits of international Aichi protection and restoration
           targets for future epiphyte metapopulations
    • Authors: Alejandro Ruete; Mari T. Jönsson, Tord Snäll
      Pages: 118 - 128
      Abstract: More than half way towards the deadline for 2020 Aichi targets, a key question is whether the metapopulation dynamics of dispersal-restricted habitat specialists can be sustained under current international targets of protection and restoration.We present the first metapopulation projections under scenarios of multiple Aichi biodiversity targets of protecting high-quality habitats and restoring suboptimal quality habitats under management. We simulate 200 years of metapopulation dynamics of nine old-growth beech (Fagus sylvatica)-associated epiphytic lichens, under a range of protection and restoration scenarios in a realistic landscape realm.Protection was generally more efficient than restoration, where protection resulted in a constant increase in occupancy over time. However, projections showed that substantial increments in the number of occupied protected beech stands will most likely occur within the next 100–200 years. The time frame was dependent on species-specific dispersal restriction, occupancy levels at onset and forest-age requirements. Suboptimally restored beech stands increased lichen metapopulation sizes over a transient period and shortened the time for dispersal-restricted species to reach higher occupancy levels inside protected areas of the landscape (c. 85–125 years).Synthesis and applications. Based on projections of metapopulation dynamics of species associated with old-growth forest, we argue that a combination of protection and restoration with the shortest possible time frame for increasing occupancy is the safest strategy. This is especially important under climatic and socio-political changes that are unforeseeable over centuries. If choosing between conservation strategies, highest priority should be given to increased protection because it means larger metapopulation sizes of these species on the long term.
      PubDate: 2017-08-06T23:10:26.528017-05:
      DOI: 10.1111/1365-2664.12964
       
  • Evaluating the success of wildlife crossing structures using genetic
           approaches and an experimental design: Lessons from a gliding mammal
    • Authors: Kylie Soanes; Andrea C. Taylor, Paul Sunnucks, Peter A. Vesk, Silvana Cesarini, Rodney Ree
      Pages: 129 - 138
      Abstract: Millions of dollars are spent on wildlife crossing structures intended to reduce the barrier effects of roads on wildlife. However, we know little about the degree to which these structures facilitate dispersal and gene flow.Our study incorporates two elements that are rarely used in the evaluation of wildlife crossing structures: an experimental design including a before and after comparison, and the use of genetic techniques to demonstrate effects on gene flow at both population and individual levels. We evaluated the effect of wildlife crossing structures (canopy bridges and glider poles) on a gliding mammal, the squirrel glider (Petaurus norfolcensis). We genotyped 399 individuals at eight microsatellite markers to analyse population structure, first-generation migrants and parentage relationships.We found that the freeway was not a complete genetic barrier, with a strong effect evident at only one site. We hypothesise that the presence of corridors alongside the freeway and throughout the surrounding landscape facilitated circuitous detours for squirrel gliders.Installing a crossing structure at the location with a strong barrier effect restored gene flow within just 5 years of mitigation.Synthesis and applications. Our study highlights the importance of using genetic techniques not just to evaluate the success of road-crossing structures for wildlife, but also to guide their placement within the landscape. Managers wishing to reduce the effects of linear infrastructure on squirrel gliders and other arboreal mammals should aim to preserve and enhance vegetation along roadsides and within centre medians, as well as mitigate large gaps by implementing wildlife crossing structures.
      PubDate: 2017-08-13T23:30:44.091343-05:
      DOI: 10.1111/1365-2664.12966
       
  • Effective implementation of age restrictions increases selectivity of
           sport hunting of the African lion
    • Authors: Colleen M. Begg; Jennifer R. B. Miller, Keith S. Begg
      Pages: 139 - 146
      Abstract: Sport hunting of wildlife can play a role in conservation but can also drive population declines if not managed sustainably. Previous simulation modelling found that large felid species could theoretically be hunted sustainably by restricting harvests to older individuals that have likely reproduced. Several African countries currently use age-based hunting for lions although the outcomes have yet to be evaluated in a wild population.Here we provide the first empirical evidence that a system of incentives sufficiently encouraged age-based hunting and reduced offtake of a wild felid, thereby reducing the potential risk of unsustainable hunting on a threatened species. We examined long-term hunting data and the lion population trend in Niassa National Reserve, Mozambique.To incentivise hunter compliance, a “points” system was developed, which rewards operators that harvest lions older than the 6-year minimum trophy age recommended for sustainable hunting and penalises operators that hunt “underage” lions (6 years), from 25% of offtakes in 2004 to 100% by 2014.Simultaneously, the number of lions and percentage of quota harvested decreased, resulting in lower lion offtakes. Following an initial decrease after enforcement of the ageing system, the percentage of hunts harvesting lions stabilised, demonstrating that hunters successfully located and aged older lions.Synthesis and applications. Evidence suggests that age restrictions combined with an incentive-based points system regulated sport hunting and reduced pressure on the lion population. We attribute the successful implementation of this management system to: (1) committed, consistent enforcement by management authorities, (2) genuine involvement of all stakeholders from the start, (3) annual auditing by an independent third party, (4) the reliable, transparent, straightforward ageing process and (5) the simple, pragmatic points system for incentivising hunter compliance. Our study demonstrates that the use of age restrictions can increase the selectivity of sport hunting and lower trophy offtakes to reduce the possibility of unsustainable sport hunting negatively impacting species populations in the absence of reliable estimates of population size. It must be noted, however, that there was no measurable change in the lion numbers over the past decade that could be attributed to the implementation of this policy alone.
      PubDate: 2017-07-10T00:15:25.695105-05:
      DOI: 10.1111/1365-2664.12951
       
  • Predator exposure improves anti-predator responses in a threatened mammal
    • Authors: Rebecca West; Mike Letnic, Daniel T. Blumstein, Katherine E. Moseby
      Pages: 147 - 156
      Abstract: Incorporating an understanding of animal behaviour into conservation programmes can influence conservation outcomes. Exotic predators can have devastating impacts on native prey species and thwart reintroduction efforts, in part due to prey naïveté caused by an absence of co-evolution between predators and prey. Attempts have been made to improve the anti-predator behaviours of reintroduced native prey by conducting laboratory-based predator recognition training but results have been varied and have rarely led to improved survival in reintroduction programmes.We investigated whether in situ predator exposure could improve anti-predator responses of a predator-naïve mammal by exposing prey populations to low densities of introduced predators under controlled conditions. We reintroduced 352 burrowing bettongs to a 26-km2 fenced exclosure at the Arid Recovery Reserve in South Australia and exposed them to feral cats (density 0.03–0.15 cats/km2) over an 18-month period. At the same time, we translocated a different group of bettongs into an exclosure free of introduced predators, as a control. We compared three behaviours (flight initiation distances, trap docility and behaviour at feeding trays) of cat-exposed and control bettongs before the translocations, then at 6, 12 and 18 months post-translocation.Cat-exposed bettongs displayed changes in behaviour that suggested increased wariness, relative to control bettongs. At 18 months post-reintroduction, cat-exposed bettongs had greater flight initiation distances and approached feed trays more slowly than control bettongs. Cat-exposed bettongs also increased their trap docility over time.Synthesis and applications. Translocation is recommended as a conservation tool for many threatened species yet success rates are generally low. We demonstrate that controlled levels of in situ predator exposure can increase wariness in the behaviour of naïve prey. Our findings provide support for the hypothesis that in situ predator exposure could be used as a method to improve the anti-predator responses of predator-naïve threatened species populations.
      PubDate: 2017-07-05T01:05:21.433569-05:
      DOI: 10.1111/1365-2664.12947
       
  • Generalized spatial mark–resight models with an application to
           grizzly bears
    • Authors: Jesse Whittington; Mark Hebblewhite, Richard B. Chandler
      Pages: 157 - 168
      Abstract: The high cost associated with capture–recapture studies presents a major challenge when monitoring and managing wildlife populations. Recently developed spatial mark–resight (SMR) models were proposed as a cost-effective alternative because they only require a single marking event. However, existing SMR models ignore the marking process and make the tenuous assumption that marked and unmarked populations have the same encounter probabilities. This assumption will be violated in most situations because the marking process results in different spatial distributions of marked and unmarked animals.We developed a generalized SMR model that includes sub-models for the marking and resighting processes, thereby relaxing the assumption that marked and unmarked populations have the same spatial distributions and encounter probabilities.Our simulation study demonstrated that conventional SMR models produce biased density estimates with low credible interval coverage (CIC) when marked and unmarked animals had differing spatial distributions. In contrast, generalized SMR models produced unbiased density estimates with correct CIC in all scenarios.We applied our SMR model to grizzly bear (Ursus arctos) data where the marking process occurred along a transportation route through Banff and Yoho National Parks, Canada. Twenty-two grizzly bears were trapped, fitted with radiocollars and then detected along with unmarked bears on 214 remote cameras. Closed population density estimates (posterior median ± 1 SD) averaged from 2012 to 2014 were much lower for conventional SMR models (7.4 ± 1.0 bears per 1,000 km2) than for generalized SMR models (12.4 ± 1.5). When compared to previous DNA-based estimates, conventional SMR estimates erroneously suggested a 51% decline in density. Conversely, generalized SMR estimates were similar to previous estimates, indicating that the grizzly bear population was relatively stable.Synthesis and applications. Mark–resight studies often cost less than capture–recapture studies, but require that marked and unmarked animals have equal encounter rates. Generalized spatial mark–resight models relax this assumption by including sub-models for both the marking and resighting processes. They produce unbiased density estimates even when marked and unmarked animals have differing spatial distributions and encounter rates. They thus provide a cost-effective and widely applicable approach for estimating the density of wildlife populations.
      PubDate: 2017-07-20T23:40:36.877077-05:
      DOI: 10.1111/1365-2664.12954
       
  • Biodiversity change is uncoupled from species richness trends:
           Consequences for conservation and monitoring
    • Authors: Helmut Hillebrand; Bernd Blasius, Elizabeth T. Borer, Jonathan M. Chase, John A. Downing, Britas Klemens Eriksson, Christopher T. Filstrup, W. Stanley Harpole, Dorothee Hodapp, Stefano Larsen, Aleksandra M. Lewandowska, Eric W. Seabloom, Dedmer B. Van de Waal, Alexey B. Ryabov
      Pages: 169 - 184
      Abstract: Global concern about human impact on biological diversity has triggered an intense research agenda on drivers and consequences of biodiversity change in parallel with international policy seeking to conserve biodiversity and associated ecosystem functions. Quantifying the trends in biodiversity is far from trivial, however, as recently documented by meta-analyses, which report little if any net change in local species richness through time.Here, we summarise several limitations of species richness as a metric of biodiversity change and show that the expectation of directional species richness trends under changing conditions is invalid. Instead, we illustrate how a set of species turnover indices provide more information content regarding temporal trends in biodiversity, as they reflect how dominance and identity shift in communities over time.We apply these metrics to three monitoring datasets representing different ecosystem types. In all datasets, nearly complete species turnover occurred, but this was disconnected from any species richness trends. Instead, turnover was strongly influenced by changes in species presence (identities) and dominance (abundances). We further show that these metrics can detect phases of strong compositional shifts in monitoring data and thus identify a different aspect of biodiversity change decoupled from species richness.Synthesis and applications: Temporal trends in species richness are insufficient to capture key changes in biodiversity in changing environments. In fact, reductions in environmental quality can lead to transient increases in species richness if immigration or extinction has different temporal dynamics. Thus, biodiversity monitoring programmes need to go beyond analyses of trends in richness in favour of more meaningful assessments of biodiversity change.
      PubDate: 2017-08-01T00:31:40.642607-05:
      DOI: 10.1111/1365-2664.12959
       
  • The role of livestock intensification and landscape structure in
           maintaining tropical biodiversity
    • Authors: Fredy Alvarado; Federico Escobar, David R. Williams, Víctor Arroyo-Rodríguez, Fernando Escobar-Hernández
      Pages: 185 - 194
      Abstract: As tropical cattle ranching continues to expand, successful conservation will require an improved understanding of the relative impacts of different livestock systems and landscape structure on biodiversity. Here, we provide the first empirical and multi-scale assessment of the relative effects of livestock intensification and landscape structure on biodiversity in the threatened tropical dry forests of Mesoamerica.We used a dataset of dung beetles (169,372 individuals from 33 species) collected from 20 1-km2 landscapes, ranging from zero-yielding forest sites to high-yield cattle ranches and maize farms, to investigate the relative effect of livestock intensification (net cattle production; macrocyclic lactone use; annual dung production) and landscape structure (landscape composition and configuration) at multiple spatial scales on different attributes of dung beetle communities using a multi-model averaging approach.Dung beetle species richness, biomass and composition were more strongly related to landscape structure than to livestock intensification.Forest cover was the best predictor of dung beetle assemblages, being positively related to species diversity and biomass across multiple spatial scales. The use of macrocyclic lactones was strong and negatively related to dung beetle communities at the local scale.Synthesis and applications: Maximising forest protection through a “land sparing” strategy is likely to be the best strategy for reducing negative impacts of cattle farming on Neotropical dung beetle communities. However, increasing or maintaining yields while reducing agrochemical inputs will be important for conserving on-farm biodiversity and the ecosystem services that dung beetles provide in livestock-dominated landscapes.
      PubDate: 2017-07-14T23:00:54.288103-05:
      DOI: 10.1111/1365-2664.12957
       
  • Managing trap-nesting bees as crop pollinators: Spatiotemporal effects of
           floral resources and antagonists
    • Authors: Matteo Dainese; Verena Riedinger, Andrea Holzschuh, David Kleijn, Jeroen Scheper, Ingolf Steffan-Dewenter
      Pages: 195 - 204
      Abstract: The decline of managed honeybees and the rapid expansion of mass-flowering crops increase the risk of pollination limitation in crops and raise questions about novel management approaches for wild pollinators in agroecosystems. Adding artificial nesting sites, such as trap nests, can promote cavity-nesting bees in agroecosystems, but effectiveness could be limited by the availability of floral resources in the surrounding landscape and by natural antagonists.In two European regions, we exposed artificial trap nests in paired field boundaries adjacent to oilseed rape (OSR) fields or non-flowering crops for 2 years within 32 landscapes covering two independent gradients of OSR cover and semi-natural habitat (SNH) cover in the landscape. We analysed the effects of local and landscape-wide floral resource availability, land-use intensity, landscape complexity and natural antagonists on community composition and population dynamics of trap-nesting bees.Numbers of brood cells showed a strong, three-fold increase in response to the additional nesting sites. Species richness and abundance of cavity-nesting bees that were active during OSR flowering increased significantly with increasing amounts of early season landscape-wide floral resource availability, such as the cultivation of OSR. Later foraging species benefited instead from the availability of late-season alternative flower resources or SNH cover once the mass-flowering had ceased. Density-dependent parasitism increased following mass-flowering, while no density-dependent effect was found during mass-flowering.Structural equation modelling revealed that the influence of floral resource availability on community growth rate was mediated by community size. Community size showed a strong negative effect on community growth rate. Despite positive density-dependent parasitism, antagonists had only weak regulating effects on community growth rate.Synthesis and applications. Trap-nesting bee populations grow markedly with the increasing availability of food resources in the landscape and effectiveness of trap nests is only marginally limited by natural antagonists. Thus, trap nests could be a simple pollinator-supporting strategy to accompany the current expansion of mass-flowering crops and to ensure pollination services for insect-pollinated crops. Trap nests benefit, not only early season active generalist bees during oilseed rape flowering, but also species with later phenology if accompanied by other pollinator-supporting practices.
      PubDate: 2017-06-13T08:55:27.425171-05:
      DOI: 10.1111/1365-2664.12930
       
  • The importance of scattered trees for biodiversity conservation: A global
           meta-analysis
    • Authors: Jayme A. Prevedello; Mauricio Almeida-Gomes, David B. Lindenmayer
      Pages: 205 - 214
      Abstract: Scattered trees are thought to be keystone structures for biodiversity in landscapes world-wide. However, such trees have been largely neglected by researchers and their importance for biodiversity remains unclear.We completed a global meta-analysis to quantify relationships between scattered trees and the species richness, abundance and composition of vertebrates, arthropods and plants. First, we tested whether areas near scattered trees support higher levels of species richness and abundance than nearby open areas. Second, we compared levels of species richness and abundance in matrix areas with scattered trees and areas embedded within nearby habitat patches. We also compared the composition of biological communities inhabiting habitat patches, open areas and areas with scattered trees.A total of 62 studies contained suitable data for our quantitative analyses. The local abundance of arthropods, vertebrates and woody plants was 60%–430% greater and overall species richness was 50%–100% higher in areas with scattered trees than in open areas. Conversely, for herbaceous plants, there was no consistent relationship between species abundance and the occurrence of scattered trees, although species richness was, on average, 43% lower.The abundance and richness of all taxonomic groups was similar in matrix areas supporting scattered trees and habitat patches, although the species richness of epiphytes was, on average, 50% higher in habitat patches. Communities inhabiting habitat patches were more similar in composition to the communities inhabiting areas with scattered trees, and less similar to the communities of open areas.Synthesis and applications. Areas with scattered trees support greater levels of biodiversity than open areas, as well as communities that are more similar to those inhabiting habitat patches. Scattered trees can be regarded as keystone structures for vertebrates, arthropods and terrestrial plants in landscapes world-wide. The maintenance of scattered trees may be compatible with livestock grazing in some agricultural landscapes. Greater management effort and targeted, long-term policies are needed to retain or re-establish scattered trees in many farming landscapes in both forest and non-forest biomes around the world.
      PubDate: 2017-06-18T23:37:27.622935-05:
      DOI: 10.1111/1365-2664.12943
       
  • Enhancing plant diversity in a novel grassland using seed addition
    • Authors: Tara J. Zamin; Alex Jolly, Steve Sinclair, John W. Morgan, Joslin L. Moore
      Pages: 215 - 224
      Abstract: Restoration of novel ecosystems to a historical benchmark may not always be possible or advisable. Novel ecosystems may be managed by targeting specific components and accepting the novelty of other ecosystem attributes. The feasibility of this component-wise management of novel ecosystems has rarely been tested.In a novel grassland, where C3 grasses have replaced C4 grasses, nutrients have been elevated, and diversity has been lost due to a history of agricultural land use, we aimed to return diversity using seed addition, without altering the dominant grass matrix or nutrient status. Using direct seeding, with and without soil disturbance, we assessed the ability of 10 species of native forbs to establish.Eight of the 10 seeded species established in the first year. Soil disturbance increased establishment success by 50%, while high levels of exotic cover decreased it by 24%. Establishment was inversely related to total plant cover at sowing, with a 10% increase in initial plant cover decreasing establishment by 47%.By the third year, six of the eight species persisted and five were flowering. Survival and reproduction in the third year was not associated with the soil disturbance treatment or plant cover.Synthesis and applications. We show that native plant species can be re-established in grasslands where abiotic and biotic conditions are novel relative to their reference state. This suggests that the conservation value of novel ecosystems can be enhanced using simple restoration tools that target specific ecosystem components.
      PubDate: 2017-08-21T05:11:44.983599-05:
      DOI: 10.1111/1365-2664.12963
       
  • Ecological engineering through fire-herbivory feedbacks drives the
           formation of savanna grazing lawns
    • Authors: Jason E. Donaldson; Sally Archibald, Navashni Govender, Drew Pollard, Zoë Luhdo, Catherine L. Parr
      Pages: 225 - 235
      Abstract: Variation in grass height is beneficial to biodiversity conservation in savanna landscapes. Theory predicts that small fires can promote short-grass areas within savannas. We experimentally assessed the influence of fire season and size on grass height and the resultant response of wild grazer communities and tested three hypotheses: (1) repeated small fires in tall-grass savannas increase short-grass grazer densities in the post-burn environment; (2) increased grazer densities maintain grass height in a short, palatable state and drive feedbacks that exclude fire; and (3) late-dry season burns concentrate grazers more effectively than early dry season burns.We repeatedly applied annual treatments (unburned, early- and late-burns) in 0.25-, 5- and 25-ha plots over a period of 3 years in a tall-grass savanna system in Kruger National Park, South Africa. Dung counts for grazer density and grass height data were collected along 50-m transects. Grass height was measured in paired 1-m2 herbivore exclosures on plots before and after applied fires.Dung data indicate that wildebeest occurred most frequently in grass heights below 5 cm. Their preference for plots regardless of fire size or season increased over time with each repeated burn. Zebra and buffalo favoured burns immediately post-fire, but buffalo did not actively select for burnt areas over longer time periods.By the second year of treatment, herbivory maintained 28% and 91% of the grass height below 10 cm in the early- and late-season burns respectively. In contrast, herbivory on the unburned treatments had no effect on grass height.Synthesis and applications. Fires less than 25 ha in size attracted sufficient grazing herbivores to shorten grass height. Repetition of the fire treatments resulted in the active selection of these areas in the longer term by wildebeest, impala and, to a lesser degree, zebra. Grazing pressure was high enough to initiate positive feedbacks and maintain lawns after only two seasons of burning and, depending on the season of burn, reduced grass height to a level that excluded repeat fires. Our study demonstrated that theory on grazer use of the post-fire environment can be implemented practically by applying small repeated burns to promote the formation of short-grass areas within savannas.
      PubDate: 2017-07-25T23:15:49.349885-05:
      DOI: 10.1111/1365-2664.12956
       
  • Season and dominant species effects on plant trait-ecosystem function
           relationships in intensively grazed grassland
    • Authors: Kate H. Orwin; Norman W.H. Mason, Olivia M. Jordan, Suzanne M. Lambie, Bryan A. Stevenson, Paul L. Mudge
      Pages: 236 - 245
      Abstract: Grazed pasture managers are increasingly being asked to enhance productivity while simultaneously reducing environmental impacts. Using plant traits to design plant communities that optimise ecosystem functions (e.g. productivity, nitrogen retention) may help achieve this. However, trait–function relationships in intensively grazed systems are largely untested.We used a forage diversity experiment, intensively grazed by cows (i.e. 10–12 times per year), to test whether community leaf and root traits were consistent predictors of ecosystem functioning across seasons and dominant species identities. Diversity treatments consisted of adding further species to either a Lolium perenne–Trifolium repens or a Festuca arundinacea–T. repens base mixture.Plant traits were better predictors of functioning in systems dominated by L. perenne than by F. arundinacea. Above-ground productivity, root biomass and soil nitrate concentrations were related to traits in all seasons, but the ability of traits to predict carbon cycling measures, and to a lesser extent, net N mineralisation rates, varied strongly across seasons.Leaf traits were better predictors of functioning than root traits. Despite limited trait breadth, leaf functional trait diversity was correlated with most ecosystem functions in at least one season, but effects were sometimes negative. Trait–function relationships were not always in the expected direction.Synthesis and applications. Our results indicate that manipulating plant community traits has potential to improve some ecosystem functions for some seasons in intensively grazed systems. However, the variable nature of the trait–function relationships found suggests that a deeper understanding of why and when traits relate to ecosystem functioning is required before managers can be confident that using a trait-based approach will consistently improve outcomes.
      PubDate: 2017-06-26T00:19:08.479109-05:
      DOI: 10.1111/1365-2664.12939
       
  • Intensive forest harvesting increases susceptibility of northern forest
           soils to carbon, nitrogen and phosphorus loss
    • Authors: Alexandra M. Hume; Han Y. H. Chen, Anthony R. Taylor
      Pages: 246 - 255
      Abstract: Understanding the impact of forest harvesting is critical to sustainable forest management, yet there remains much uncertainty regarding how harvesting affects soil carbon (C), nitrogen (N) and phosphorus (P) dynamics.Here, we conducted a global meta-analysis of 808 observations from 49 studies to test the effects of harvesting on the stocks and concentrations of soil C, N and P and C:N:P ratios relative to uncut control stands.With all harvesting intensities combined, C stock was unaffected by harvesting in either the forest floor or mineral soil, while harvesting reduced forest floor [C], [N] and [P] and C:N ratio, increased the mineral soil [C] and C:N ratio, but reduced mineral soil N stock. The impacts of harvesting on forest floor C and N stocks, C:P and N:P and mineral soil [C] and [N] changed from no effects by partial, stem-only and whole-tree harvesting (WTH) to significantly negative effects by the harvesting coupled with fire. Stem-only and WTH similarly reduced forest floor [P]. The negative effects of harvesting were most pronounced in conifer stands. Soil [C], [N] and C:N decreased with time since harvesting, but soil [P] did not, resulting in an increase in forest floor N:P.Synthesis and applications. Our findings highlight the importance of harvest intensity and rotation length on long-term soil nutrient availability when managing forests. Furthermore, the lag in the recovery of phosphorus concentration following harvesting may indicate a decoupling of the phosphorus cycle from those of carbon and nitrogen, and a potential concern in managed forests.
      PubDate: 2017-06-19T23:35:41.349183-05:
      DOI: 10.1111/1365-2664.12942
       
  • Compensatory dynamics maintain bird phylogenetic diversity in fragmented
           tropical landscapes
    • Authors: José Carlos Morante-Filho; Víctor Arroyo-Rodríguez, Edyla R. Andrade, Bráulio A. Santos, Eliana Cazetta, Deborah Faria
      Pages: 256 - 266
      Abstract: Tropical forest loss can drive the extinction of forest-dependent species. Yet, non-forest species can proliferate in deforested landscapes, thus enabling community-level attributes (e.g. total abundance and richness) to be maintained in the remaining forest patches. Such compensatory dynamics have been, however, poorly investigated regarding the phylogenetic dimension of species diversity. Here, we assessed whether compensatory dynamics can stabilize the phylogenetic richness, divergence and structure of bird communities in response to forest loss in two regions in the Brazilian Atlantic forest, each under with different levels of land use intensification.We surveyed birds in 40 forest sites, and assessed the response of five phylogenetic metrics to forest cover measured in local (600-m radius) landscapes. We separately assessed the entire community, forest-dependent and non-forest-dependent species and used information-theoretic criteria to assess the effect of forest cover on each response variable. In particular, we evaluated the plausibility of four models: a null model (no effect of forest cover), a linear model, a power law model (nonlinear effect) and an analysis of covariance model (to assess whether the effect of forest cover differed between regions).Forest cover varied from 7% to 98%, and was positively related to the phylogenetic richness of forest-dependent species, but negatively related to the phylogenetic richness and divergence of non-forest birds, particularly in the more disturbed region. As consequence, the phylogenetic richness and divergence of the entire community were weakly related to forest cover.Forest birds were less phylogenetically clustered in sites surrounded by lower forest cover, but the phylogenetic structure of non-forest birds was independent of forest cover.Synthesis and applications. The phylogenetic impoverishment of forest-dependent birds is offset by the phylogenetic enrichment and divergence of non-forest-dependent birds in severely tropical deforested landscapes. These compensatory dynamics suggest that both bird groups are important for safeguarding bird evolutionary diversity in human-modified landscapes. Although deforested landscapes are reservoirs of bird phylogenetic diversity, suggesting that ecosystem functioning may be maintained in these sites, preventing further deforestation is urgently needed to preserve forest birds and their key ecological roles in the ecosystem.
      PubDate: 2017-07-20T23:45:36.758546-05:
      DOI: 10.1111/1365-2664.12962
       
  • The impact of even-aged and uneven-aged forest management on regional
           biodiversity of multiple taxa in European beech forests
    • Authors: Peter Schall; Martin M. Gossner, Steffi Heinrichs, Markus Fischer, Steffen Boch, Daniel Prati, Kirsten Jung, Vanessa Baumgartner, Stefan Blaser, Stefan Böhm, François Buscot, Rolf Daniel, Kezia Goldmann, Kristin Kaiser, Tiemo Kahl, Markus Lange, Jörg Müller, Jörg Overmann, Swen C. Renner, Ernst-Detlef Schulze, Johannes Sikorski, Marco Tschapka, Manfred Türke, Wolfgang W. Weisser, Bernd Wemheuer, Tesfaye Wubet, Christian Ammer
      Pages: 267 - 278
      Abstract: For managed temperate forests, conservationists and policymakers favour fine-grained uneven-aged (UEA) management over more traditional coarse-grained even-aged (EA) management, based on the assumption that within-stand habitat heterogeneity enhances biodiversity. There is, however, little empirical evidence to support this assumption. We investigated for the first time how differently grained forest management systems affect the biodiversity of multiple above- and below-ground taxa across spatial scales.We sampled 15 taxa of animals, plants, fungi and bacteria within the largest contiguous beech forest landscape of Germany and classified them into functional groups. Selected forest stands have been managed for more than a century at different spatial grains. The EA (coarse-grained management) and UEA (fine-grained) forests are comparable in spatial arrangement, climate and soil conditions. These were compared to forests of a nearby national park that have been unmanaged for at least 20 years. We used diversity accumulation curves to compare γ-diversity for Hill numbers 0D (species richness), 1D (Shannon diversity) and 2D (Simpson diversity) between the management systems. Beta diversity was quantified as multiple-site dissimilarity.Gamma diversity was higher in EA than in UEA forests for at least one of the three Hill numbers for six taxa (up to 77%), while eight showed no difference. Only bacteria showed the opposite pattern. Higher γ-diversity in EA forests was also found for forest specialists and saproxylic beetles.Between-stand β-diversity was higher in EA than in UEA forests for one-third (all species) and half (forest specialists) of all taxa, driven by environmental heterogeneity between age-classes, while α-diversity showed no directional response across taxa or for forest specialists.Synthesis and applications. Comparing EA and uneven-aged forest management in Central European beech forests, our results show that a mosaic of different age-classes is more important for regional biodiversity than high within-stand heterogeneity. We suggest reconsidering the current trend of replacing even-aged management in temperate forests. Instead, the variability of stages and stand structures should be increased to promote landscape-scale biodiversity.
      PubDate: 2017-06-30T23:01:13.926602-05:
      DOI: 10.1111/1365-2664.12950
       
  • Impacts of salvage logging on biodiversity: A meta-analysis
    • Authors: Simon Thorn; Claus Bässler, Roland Brandl, Philip J. Burton, Rebecca Cahall, John L. Campbell, Jorge Castro, Chang-Yong Choi, Tyler Cobb, Daniel C. Donato, Ewa Durska, Joseph B. Fontaine, Sylvie Gauthier, Christian Hebert, Torsten Hothorn, Richard L. Hutto, Eun-Jae Lee, Alexandro B. Leverkus, David B. Lindenmayer, Martin K. Obrist, Josep Rost, Sebastian Seibold, Rupert Seidl, Dominik Thom, Kaysandra Waldron, Beat Wermelinger, Maria-Barbara Winter, Michal Zmihorski, Jörg Müller
      Pages: 279 - 289
      Abstract: Logging to “salvage” economic returns from forests affected by natural disturbances has become increasingly prevalent globally. Despite potential negative effects on biodiversity, salvage logging is often conducted, even in areas otherwise excluded from logging and reserved for nature conservation, inter alia because strategic priorities for post-disturbance management are widely lacking.A review of the existing literature revealed that most studies investigating the effects of salvage logging on biodiversity have been conducted less than 5 years following natural disturbances, and focused on non-saproxylic organisms.A meta-analysis across 24 species groups revealed that salvage logging significantly decreases numbers of species of eight taxonomic groups. Richness of dead wood dependent taxa (i.e. saproxylic organisms) decreased more strongly than richness of non-saproxylic taxa. In contrast, taxonomic groups typically associated with open habitats increased in the number of species after salvage logging.By analysing 134 original species abundance matrices, we demonstrate that salvage logging significantly alters community composition in 7 of 17 species groups, particularly affecting saproxylic assemblages.Synthesis and applications. Our results suggest that salvage logging is not consistent with the management objectives of protected areas. Substantial changes, such as the retention of dead wood in naturally disturbed forests, are needed to support biodiversity. Future research should investigate the amount and spatio-temporal distribution of retained dead wood needed to maintain all components of biodiversity.
      PubDate: 2017-07-05T05:46:11.662279-05:
      DOI: 10.1111/1365-2664.12945
       
  • Woodland ectomycorrhizal fungi benefit from large-scale reduction in
           nitrogen deposition in the Netherlands
    • Authors: Arco J. Strien; Menno Boomsluiter, Machiel E. Noordeloos, Richard J. T. Verweij, Thomas W. Kuyper
      Pages: 290 - 298
      Abstract: Woodland ectomycorrhizal (ECM) fungal species declined considerably in the Netherlands in the late 20th century, mainly due to raised levels of atmospheric nitrogen deposition. Environmental measures have been taken to reduce this deposition, but it remains unclear whether and to what extent ECM species have benefitted from these.We hypothesized that ECM species, especially those species that are known to be nitrophobic, that is, sensitive to nitrogen loading, have recovered to some extent from the reduction in nitrogen deposition after 1994. We further hypothesized that, due to legacy effects of deposition, recovery has been stronger in regions where deposition levels have previously been lower.To test these hypotheses, we analysed long-term opportunistic data, that is, observations collected without standardized field method. We applied data filtering and a modified List Length method to adjust for potential biases in these data. The removal of bias left us with two periods to examine ECM species trends: before (1965–1985) and after (1994–2013) deposition reduction started [in 1994].We compared trends in ECM species in 1965–1985 with those in 1994–2013. Multispecies indicators were used to summarize the findings of ECM species, and to compare these with results of litter saprotrophic species and wood saprotrophic and wood parasitic species.We found that (1) most trends switched in direction from negative to positive after the reduction in nitrogen deposition began; (2) these trends were more pronounced for nitrophobic ECM species than for nitrotolerant ECM species; (3) trends for ECM species differed from those of the other functional groups; and (4) recovery was stronger in the region with a history of lower deposition.Policy implications. Our results suggest that woodland ectomycorrhizal species benefit substantially from environmental measures to reduce nitrogen deposition. Our study is one of few scientific studies to date documenting evidence of success of large-scale (nation-wide) environmental measures. We have demonstrated that opportunistic citizen science data can be used for the detection of species trends, but it is essential to examine and control for potential bias in the data.
      PubDate: 2017-06-29T07:35:46.633791-05:
      DOI: 10.1111/1365-2664.12944
       
  • Legacy effects of diversity in space and time driven by winter cover crop
           biomass and nitrogen concentration
    • Authors: Janna M. Barel; Thomas W. Kuyper, Wietse Boer, Jacob C. Douma, Gerlinde B. De Deyn
      Pages: 299 - 310
      Abstract: Plant diversity can increase nitrogen cycling and decrease soil-borne pests, which are feedback mechanisms influencing subsequent plant growth. The relative strength of these mechanisms is unclear, as is the influence of preceding plant quantity and quality. Here, we studied how plant diversity in space and time influences subsequent crop growth.During 2 years, we rotated two main crops (Avena sativa, Cichorium endivia) with four winter cover crop (WCC) species in monocultures and mixtures. We hypothesized that, relative to monocultures, WCC mixtures promote WCC biomass (quantity) and nitrogen concentration (quality), soil mineral nitrogen, soil organic matter, and reduce plant-feeding nematode abundance. Additionally, we predicted that preceding crops modified WCC legacies. By structural equation modelling (SEM), we tested the relative importance of WCC shoot biomass and nitrogen concentration on succeeding crop productivity directly and indirectly via nitrogen cycling and root-feeding nematode abundance.WCC shoot biomass, soil properties and succeeding Avena productivity were affected by first-season cropping, whereas subsequent Cichorium only responded to the WCC treatments. WCC mixtures’ productivity and nitrogen concentration showed over- and under-yielding, depending on mixture composition. Soil nitrogen and nematode abundance did not display WCC mixture effects. Soil organic matter was lower than expected after Raphanus sativus + Vicia sativa mixture. Subsequent Avena productivity depended upon mixture composition, whereas final Cichorium productivity was unresponsive to WCC mixtures. SEM indicated that WCC legacy effects on subsequent Avena (R2 = 0.52) and Cichorium (R2 = 0.59) productivity were driven by WCC biomass and nitrogen concentration, although not by the quantified soil properties.Synthesis and applications. Through understanding plant–soil feedback, legacy effects of plant species and species mixtures can be employed for sustainable management of agro-ecosystems. Biomass and nitrogen concentration of plants returned to the soil stimulate subsequent plant productivity. Winter cover crop quantity and quality are both manipulable with mixtures. The specificity of spatial and temporal diversity effects warrants consideration of plant species choice in mixtures and rotations for optimal employment of beneficial legacy effects.
      PubDate: 2017-06-02T01:01:00.402227-05:
      DOI: 10.1111/1365-2664.12929
       
  • Top soil removal reduces water pollution from phosphorus and dissolved
           organic matter and lowers methane emissions from rewetted peatlands
    • Authors: Dominik Zak; Tobias Goldhammer, Alavaro Cabezas, Jörg Gelbrecht, Robert Gurke, Carola Wagner, Hendrik Reuter, Jürgen Augustin, Agata Klimkowska, Robert McInnes
      Pages: 311 - 320
      Abstract: A valid strategy to mitigate the eutrophication of water bodies due to non-point source phosphorus (P) pollution and to reduce the emissions of greenhouse gases is the rewetting of degraded peatlands. However, long-term drainage and intensive agricultural use make it unlikely that the original sink functions for nutrients and carbon (C) as well as low-nutrient conditions can be re-established within a human time perspective.We hypothesized that the removal of the upper degraded peat layer can be a suitable measure to avoid the negative implications of excess mobilization of P and C after rewetting. To evaluate the effect of top soil removal (TSR) we performed lab and field experiments in six inundated peatlands in northern Germany without TSR compared to six inundated sites with TSR. In addition, we included data from a rewetted peatland where the degraded peat had been removed from about half of the area and groundwater level was just beneath the soil surface.The results emphasized that following inundation newly formed detritus mud layers overlying the former peat surface are the dominating source for P and methane in particular in sites without TSR but also in sites with TSR, although at significantly lower rates. Although highly decomposed peat released more or less no methane, dissolved organic matter mobilization was highest in this substrate while less decomposed peat was characterized in general by lowest rates of mobilization.Synthesis and applications. Top soil removal prior to rewetting can be a suitable method to avoid the negative consequences of the excess release of phosphorus (P) and carbon post-rewetting. We developed a simple decision support schematic to assist the peatland restoration process and to better understand the implications of top soil removal. Despite the potential benefits, top soil removal should not be declared as a universal method, as it requires detailed consideration prior to application. However, this and other research demonstrate that it is inevitable that without any further management interventions high mobilization of P, dissolved organic matter and methane may persist for centuries following rewetting of peatlands.
      PubDate: 2017-06-08T05:41:06.292292-05:
      DOI: 10.1111/1365-2664.12931
       
  • Integrating local knowledge and research to refine the management of an
           invasive non-native grass in critically endangered grassy woodlands
    • Authors: Jennifer Firn; Emma Ladouceur, Josh Dorrough
      Pages: 321 - 330
      Abstract: Globally the prevalence and impact of invasive non-native plant species is increasing rapidly. Experimentally based research aimed at supporting management is limited in its ability to keep up with this pace, partly because of the importance of understanding historical abiotic and biotic conditions. Contrastingly, landholders are in unique positions to witness species turnover in grasslands, adapt management practices in response and learn from successes and failures.This local knowledge could be crucial for identifying feasible solutions to land degradation, and ecological restoration, but local knowledge is rarely explicitly embedded in ecological research.We use a sequential exploratory strategy where we first interview (semi-directive approach) 15 landholders within the Bega region of New South Wales, Australia concerning the changing ecological characteristics of both extensively and intensively managed grassy woodlands and perceived impacts following arrival of the invasive exotic introduced species, African lovegrass (ALG), Eragrostis curvula.Based on the results of these interviews, we then conducted a field study where we tested 7 landholder-generated hypotheses at 57 sites.The field study validated many of the landholder management perceptions including: ALG was negatively correlated with species richness, canopy cover and dominant grasses like Themeda triandra. Mechanical slashing increased exotic ALG abundance. The prevalence of ALG in the soil seed bank was positively correlated with its abundance above-ground. Study observations that contradicted landholder perceptions included: ALG was not more palatable nor did its abundance decline in response to increasing soil fertility. Spot spraying with herbicides was effective at controlling abundance, despite its reputation as ineffective. Landholder observations also highlighted key hypotheses concerning modes of spread that require long-term studies including the roles of drought and overgrazing.Synthesis and applications. Overall, we found local knowledge coupled with scientific methods can act in tandem as a highly effective approach for developing management recommendations. This approach identifies local perceptions that are not substantiated by scientific data to halt potentially harmful practices, and observations that are insightful predictions about the dynamics and impacts of non-native species that need long-term experiments to corroborate scientifically.
      PubDate: 2017-06-30T02:30:25.504703-05:
      DOI: 10.1111/1365-2664.12928
       
  • Invasive pathogen drives host population collapse: Effects of a travelling
           wave of sarcoptic mange on bare-nosed wombats
    • Authors: Alynn M. Martin; Christopher P. Burridge, Janeane Ingram, Tamieka A. Fraser, Scott Carver
      Pages: 331 - 341
      Abstract: Emerging and invasive pathogens can have long-lasting impacts on susceptible wildlife populations, including localized collapse and extirpation. Management of threatening disease is of widespread interest and requires knowledge of spatiotemporal patterns of pathogen spread.Theory suggests disease spread often occurs via two patterns: homogenous mixing and travelling waves. However, high-resolution empirical data demonstrating localized (within population) disease spread patterns are rare.This study examined the spread of sarcoptic mange (aetiological agent Sarcoptes scabiei) in a population of bare-nosed wombats (Vombatus ursinus), and investigated whether pathogen spread occurred by homogenous mixing or a travelling wave.Using 7 years of population surveys and 4 years of disease severity surveys, we show that mange was first detected in the east of a wombat population in northern Tasmania, and progressed westward as a travelling wave. Wombat mortality rates reached 100% behind the wave, with a 94% decline in overall wombat abundance within the park.Synthesis and applications. Globally distributed pathogens may have severe impacts on susceptible host species. This is the first study to quantify population-level impacts of sarcoptic mange upon bare-nosed wombats, showing a wave of mange disease which resulted in a dramatic population decline. Successful management of the spread of this and similar pathogens may hinge on the capacity to establish transmission barriers at local or between-population scales.
      PubDate: 2017-08-23T03:55:30.87938-05:0
      DOI: 10.1111/1365-2664.12968
       
  • A dynamical model for invasive round goby populations reveals efficient
           and effective management options
    • Authors: Anouk N'Guyen; Philipp E. Hirsch, Claudio Bozzuto, Irene Adrian-Kalchhauser, Kristína Hôrková, Patricia Burkhardt-Holm
      Pages: 342 - 352
      Abstract: When prevention of invasive species’ introductions fails, society faces the challenge to manage invasive species in an effective and efficient way. The success of this depends on biological aspects and on cooperation between decision makers and scientists. Using the case of the round goby Neogobius melanostomus, one of Europe's “worst invasive species”, we propose an approach guiding scientists to co-produce effective and efficient population control measures in collaboration with decision makers.We surveyed the effectiveness, urgency and simplicity perceived by decision makers as well as the support of two population control options: removal of eggs and/or adults. Using a field study and a dynamical population model, we investigated the effectiveness and efficiency for both options in different population contexts.Decision makers initially seemed to lack a clear preference for either control option. After being presented with preliminary field and modelling results, decision makers mostly approved measures being developed to implement the two control options.Starting population control early after detecting the species requires in total fewer years for eradication than controlling an established population: to reach an eradication success rate of 95%, 13 years for early start vs. 18 years for late start are needed when removing eggs and adults; when removing adults only, 20 vs. 29 years are needed. Removing eggs and adults combined results in a yearly effort of 5.01 h/m2, while removing adults only results in a yearly effort of 1.76 h/m2. Thus, removing adults only proves to be the most efficient option to eradicate the population. Nonetheless, considerable effort is needed: when removing less than 57% of the adult population, eradication is not feasible, even assuming low survival and fecundity rates for the population. Furthermore, inflow of new propagules renders eradication efforts ineffective.Synthesis and applications. Scientists who aim to support decision makers in finding an optimal control strategy for invasive species need to be able to provide scientific knowledge on effectiveness and efficiency of different options. For round goby and most non-native species, eradication is only feasible if started early in recently arrived populations and if inflow of new propagules can be prevented.
      PubDate: 2017-06-30T06:46:43.592225-05:
      DOI: 10.1111/1365-2664.12934
       
  • Flow intermittence and ecosystem services in rivers of the Anthropocene
    • Authors: Thibault Datry; Andrew J. Boulton, Núria Bonada, Ken Fritz, Catherine Leigh, Eric Sauquet, Klement Tockner, Bernard Hugueny, Clifford N. Dahm
      Pages: 353 - 364
      Abstract: Intermittent rivers and ephemeral streams (IRES) are watercourses that cease flow at some point in time and space. Arguably Earth's most widespread type of flowing water, IRES are expanding where Anthropocenic climates grow drier and human demands for water escalate.However, IRES have attracted far less research than perennial rivers and are undervalued by society, jeopardizing their restoration or protection. Provision of ecosystem services by IRES is especially poorly understood, hindering their integration into management plans in most countries.We conceptualize how flow intermittence governs ecosystem service provision and transfers at local and river-basin scales during flowing, non-flowing and dry phases. Even when dry or not flowing, IRES perform multiple ecosystem services that complement those of nearby perennial rivers.Synthesis and applications. Conceptualizing how flow intermittence in rivers and streams governs ecosystem services has applied a socio-ecological perspective for validating the ecosystem services of intermittent rivers and ephemeral streams. This can be applied at all flow phases and in assessing impacts of altered flow intermittence on rivers and their ecosystem services in the Anthropocene.
      PubDate: 2017-06-26T00:19:00.970389-05:
      DOI: 10.1111/1365-2664.12941
       
  • Riparian plant guilds become simpler and most likely fewer following flow
           regulation
    • Authors: Maria Dolores Bejarano; Christer Nilsson, Francisca Constança Aguiar
      Pages: 365 - 376
      Abstract: River regulation affects riparian systems world-wide and conservation and restoration efforts are essential to retain biodiversity, and the functioning and services of riverine ecosystems. Effects of regulation on plant species richness have been widely addressed, but the filtering effect of regulation on guilds has received less attention.We used a functional trait approach to identify adaptive plant strategies through regulation-tolerant traits and predict shifts of riparian vegetation communities in response to regulation. We analysed variation in functional diversity across gradients of hydrological alteration in northern Sweden in relation to modified timing and infrequent major floods, along with frequent short-term inundation.Functional richness was similar in all study sites, but species richness declined with increasing intensity of regulation, and the species lost were largely functionally redundant (i.e. co-existing species that have similar contribution to an ecosystem function). Guilds of species intolerant to waterlogging were particularly unsuccessful in most regulated sites as they were affected by hydropower dams which replace major fluvial disturbances with frequent short inundation events. We predict that this guild will disappear, with likely consequences for the entire riverine ecosystem.Synthesis and applications. We conclude that functional traits tolerant to waterlogging or submergence and lack of major fluvial disturbances were key to understanding our results. We suggest that the functional trait approach can be integrated with knowledge of other ecosystem components to provide an understanding of ecosystem function that can be used to guide fluvial ecosystem management.
      PubDate: 2017-07-05T03:20:41.226585-05:
      DOI: 10.1111/1365-2664.12949
       
  • Enhanced ecosystem functioning following stream restoration: The roles of
           habitat heterogeneity and invertebrate species traits
    • Authors: André Frainer; Lina E. Polvi, Roland Jansson, Brendan G. McKie
      Pages: 377 - 385
      Abstract: Habitat restoration is increasingly undertaken in degraded streams and rivers to help improve biodiversity and ecosystem functioning. Follow-up assessments focused on outcomes for biodiversity have often found scant evidence for recovery, raising concerns about the efficacy of habitat restoration for improving ecological integrity. However, responses of other ecological variables, such as ecosystem process rates and the functional trait composition of biological assemblages, have been little evaluated.We assessed how the restoration of habitat heterogeneity affected multiple functional parameters in 20 boreal stream reaches encompassing both more and less extensively restored sites, as well as channelised and natural reference sites. We further assessed relationships between our functional parameters and a fluvial geomorphic measure of habitat heterogeneity.Leaf decomposition was positively related to habitat heterogeneity. This was associated with shifts in the functional composition of detritivore assemblages, with the most obligate litter consumers more prominent in reaches showing higher habitat heterogeneity. The deposition of fine particulate organic matter was consistently higher in restored than channelised sites, and was positively related to the heterogeneity gradient. Algal biomass accrual per unit area did not vary either with restoration or the heterogeneity gradient.Synthesis and applications. Our findings demonstrate that restoration of river habitat heterogeneity can enhance retention and decomposition of organic matter, key ecosystem properties underpinning ecosystem functioning and service delivery. Significantly, enhanced litter decomposition was linked with a change in the functional composition rather than diversity of detritivore assemblages. Future evaluation of the success of habitat restorations should incorporate quantification of ecosystem processes and the functional traits of biota, in addition to measures of fluvial geomorphology and more traditional biotic metrics, to facilitate a more comprehensive and mechanistic assessment of ecological responses.
      PubDate: 2017-06-13T08:50:50.161291-05:
      DOI: 10.1111/1365-2664.12932
       
  • Relationships between forest cover and fish diversity in the Amazon River
           floodplain
    • Authors: Caroline C. Arantes; Kirk O. Winemiller, Miguel Petrere, Leandro Castello, Laura L. Hess, Carlos E. C. Freitas
      Pages: 386 - 395
      Abstract: Habitat degradation leads to biodiversity loss and concomitant changes in ecosystem processes. Tropical river floodplains are highly threatened by land cover changes and support high biodiversity and important ecosystem services, but the extent to which changes in floodplain land cover affect fish biodiversity remains unknown.We combined fish and environmental data collected in situ and satellite-mapped landscape features to evaluate how fish species with different ecological strategies and assemblage structures respond to deforestation in floodplains of the Amazon River. We surveyed 462 floodplain habitats distributed along a gradient of land cover, from largely forested to severely deforested. Rather than analyse only taxonomic metrics, we employed an integrative approach that simultaneously considers different aspects of fish biodiversity (i.e. β diversity and taxonomic and functional assemblage structure) to facilitate mechanistic interpretations of the influence of land cover.Spatial patterns of fish biodiversity in the Amazon River floodplain were strongly associated with forest cover as well as local environmental conditions linked to landscape gradients. Several species and functional groups defined by life-history, feeding, swimming/microhabitat-use strategies were positively associated with forest cover. Other species, including some that would usually be considered habitat generalists and species directly dependent on autochthonous resources (e.g. planktivores), were most common in areas dominated by herbaceous vegetation or open water habitats associated with the opposite extreme of the forest cover gradient. β diversity and the degree of uniqueness of species combinations within habitats were also positively associated with forest cover.Synthesis and applications. Our results demonstrating that spatial patterns of fish biodiversity are associated with forest cover, indicate that deforestation of floodplains of the Amazon River results in spatial homogenization of fish assemblages and reduced functional diversity at both local and regional scales. Floodplains world-wide have undergone major land cover changes, with forest loss projected to increase during the next decades. Conserving fish diversity in these ecosystems requires protecting mosaics of both aquatic habitats and floodplain vegetation, with sufficient forest cover being critically important.
      PubDate: 2017-09-04T05:19:57.619147-05:
      DOI: 10.1111/1365-2664.12967
       
  • Marine mammals and sonar: Dose-response studies, the risk-disturbance
           hypothesis and the role of exposure context
    • Authors: Catriona M. Harris; Len Thomas, Erin A. Falcone, John Hildebrand, Dorian Houser, Petter H. Kvadsheim, Frans-Peter A. Lam, Patrick J. O. Miller, David J. Moretti, Andrew J. Read, Hans Slabbekoorn, Brandon L. Southall, Peter L. Tyack, Douglas Wartzok, Vincent M. Janik
      Pages: 396 - 404
      Abstract: Marine mammals may be negatively affected by anthropogenic noise. Behavioural response studies (BRS) aim to establish a relationship between noise exposure conditions (dose) from a potential stressor and associated behavioural responses of animals. A recent series of BRS have focused on the effects of naval sonar sounds on cetaceans. Here, we review the current state of understanding of naval sonar impact on marine mammals and highlight knowledge gaps and future research priorities.Many marine mammal species exhibit responses to naval sonar sounds. However, responses vary between and within individuals and populations, highlighting the importance of exposure context in modulating dose–response relationships.There is increasing support from both terrestrial and marine systems for the risk-disturbance hypothesis as an explanation for underlying response processes. This proposes that sonar sounds may be perceived by animals as a threat, evoking a response shaped by the underlying species-specific risk of predation and anti-predator strategy. An understanding of responses within both the dose–response and risk-disturbance frameworks may enhance our ability to predict responsiveness for unstudied species and populations.Many observed behavioural responses are energetically costly, but the way that these responses may lead to long-term individual and population-level impacts is poorly understood.Synthesis and applications. Behavioural response studies have greatly improved our understanding of the potential effects of naval sonar on marine mammals. Despite data gaps, we believe a dose-response approach within a risk-disturbance framework will enhance our ability to predict responsiveness for unstudied species and populations. We advocate for (1) regulatory frameworks to utilize peer-reviewed research findings when making predictions of impact, (2) regulatory frameworks to account for the inherent uncertainty in predictions of impact and (3) investment in monitoring programmes that are both directed by recent research and offer opportunities for validation of predictions at the individual and population level.
      PubDate: 2017-07-20T23:45:26.466436-05:
      DOI: 10.1111/1365-2664.12955
       
  • Mutualistic interactions amplify saltmarsh restoration success
    • Authors: Marlous Derksen-Hooijberg; Christine Angelini, Leon P. M. Lamers, Annieke Borst, Alfons Smolders, Jasper R. H. Hoogveld, Hélène Paoli, Johan Koppel, Brian R. Silliman, Tjisse Heide
      Pages: 405 - 414
      Abstract: Mounting evidence shows that the functioning and stability of coastal ecosystems often depends critically on habitat-forming foundation species such as seagrasses, mangroves and saltmarsh grasses that engage in facultative mutualistic interactions. However, although restoration science is now gradually expanding its long-standing paradigm of minimizing competition to including intraspecific, or within species, facilitation in its designs, the potential of harnessing mutualistic interactions between species for restoration purposes remains uninvestigated.Here, we experimentally tested whether a previously documented mutualism between marsh-forming Spartina alterniflora (cordgrass) and Geukensia demissa (mussels) can increase restoration success in degraded US saltmarshes.We found that co-transplanted mussels locally increased nutrients and reduced sulphide stress, thereby increasing cordgrass growth and clonal expansion by 50%. We then removed above-ground vegetation and mussels to simulate a disturbance event and discovered that cordgrass co-transplanted with mussels experienced three times greater survival than control transplants.Synthesis and applications. Our findings indicate that mussels amplify cordgrass re-colonization and resilience over spatial and temporal scales that exceed those of their actual mutualistic interaction. By experimentally demonstrating that mutualistic partners can enable foundation species to overcome stress barriers to establish and persist, we highlight that coastal restoration needs to evolve beyond the sole inclusion of intraspecific-positive interactions. In particular, we suggest that integrating mutualisms in restoration designs may powerfully enhance long-term restoration success and ecosystem resilience in the many coastal ecosystems where mutualisms involving foundation species are important ecosystem-structuring interactions.
      PubDate: 2017-07-28T23:45:58.751562-05:
      DOI: 10.1111/1365-2664.12960
       
  • Accounting for environmental uncertainty in the management of dredging
           impacts using probabilistic dose–response relationships and thresholds
    • Authors: Rebecca Fisher; Terry Walshe, Pia Bessell-Browne, Ross Jones
      Pages: 415 - 425
      Abstract: Dredging and related activities are common across nearshore marine environments, potentially threatening nearby ecosystems. Regulatory frameworks are essential for minimizing environmental impacts, yet rely heavily on a sound understanding of how ecosystems will respond to environmental stressors, and the thresholds that delineate benign and harmful conditions.Here, we use novel statistical approaches and mathematical tools to account for uncertainty in deriving in situ dose–response relationships and thresholds for the environmental management of dredging, based on estimates of the probability of non-zero mortality of corals during a dredging campaign at Barrow Island, Western Australia. Using modified receiver operating characteristic curves, we derive thresholds with explicit Type I and Type II errors rates, across the full range of primary stress pathways and exposure dimensions (intensity, frequency and duration).Monitoring coral health and mortality can be expensive and water quality indicators are often used to supplement direct receptor monitoring during dredging management. We found strong relationships between coral mortality and a range of water quality exposure metrics, lending support to the use of water quality metrics as management tools for protecting corals during dredging. Metrics based on sediment deposition were more statistically powerful than those based on either light or turbidity, but may be more difficult to implement in practice. Thresholds reflecting aversion to a false sense of security in environmental protection or aversion to the costs of false alarms varied substantially for all exposure metrics examined.Synthesis and applications. Strategies for managing environmental harm under uncertainty are critical to achieving an informed risk-weighted balance between environmental protection outcomes and development costs. Our study demonstrates the complexities of how communities respond to variable environmental exposure across a range of pressures in time and space, and the value of integrating probabilistic approaches in environmental management to account for that complexity and its associated uncertainty. Coral mortality was strongly related to a range of water quality exposure metrics associated with dredging activities, and regulatory thresholds based on water quality can provide a solid and cost-effective foundation for protecting corals during dredging. The probabilistic dose–response relationships and thresholds presented here are the first to be derived from in situ data using dredging related coral mortality and represent a step forward in integrating formal decision science approaches into environmental management.
      PubDate: 2017-06-23T00:53:23.500118-05:
      DOI: 10.1111/1365-2664.12936
       
  • Eco-engineering urban infrastructure for marine and coastal biodiversity:
           Which interventions have the greatest ecological benefit'
    • Authors: Elisabeth M. A. Strain; Celia Olabarria, Mariana Mayer-Pinto, Vivian Cumbo, Rebecca L. Morris, Ana B. Bugnot, Katherine A. Dafforn, Eliza Heery, Louise B. Firth, Paul R. Brooks, Melanie J. Bishop
      Pages: 426 - 441
      Abstract: Along urbanised coastlines, urban infrastructure is increasingly becoming the dominant habitat. These structures are often poor surrogates for natural habitats, and a diversity of eco-engineering approaches have been trialled to enhance their biodiversity, with varying success.We undertook a quantitative meta-analysis and qualitative review of 109 studies to compare the efficacy of common eco-engineering approaches (e.g. increasing texture, crevices, pits, holes, elevations and habitat-forming taxa) in enhancing the biodiversity of key functional groups of organisms, across a variety of habitat settings and spatial scales.All interventions, with one exception, increased the abundance or number of species of one or more of the functional groups considered. Nevertheless, the magnitude of effect varied markedly among groups and habitat settings. In the intertidal, interventions that provided moisture and shade had the greatest effect on the richness of sessile and mobile organisms, while water-retaining features had the greatest effect on the richness of fish. In contrast, in the subtidal, small-scale depressions which provide refuge to new recruits from predators and other environmental stressors such as waves, had higher abundances of sessile organisms while elevated structures had higher numbers and abundances of fish. The taxa that responded most positively to eco-engineering in the intertidal were those whose body size most closely matched the dimensions of the resulting intervention.Synthesis and applications. The efficacy of eco-engineering interventions varies among habitat settings and functional groups. This indicates the importance of developing site-specific approaches that match the target taxa and dominant stressors. Furthermore, because different types of intervention are effective at enhancing different groups of organisms, ideally a range of approaches should be applied simultaneously to maximise niche diversity.
      PubDate: 2017-07-27T23:21:03.142918-05:
      DOI: 10.1111/1365-2664.12961
       
  • Artificial light at night alters grassland vegetation species composition
           and phenology
    • Authors: Jonathan Bennie; Thomas W. Davies, David Cruse, Fraser Bell, Kevin J. Gaston
      Pages: 442 - 450
      Abstract: Human settlements and transport networks are growing rapidly worldwide. Since the early 20th century their expansion has been accompanied by increasing illumination of the environment at night, a trend that is likely to continue over the decades to come. Consequently, a growing proportion of the world's ecosystems are exposed to artificial light at night, profoundly altering natural cycles of light and darkness. While in recent years there have been advances in our understanding of the effects of artificial light at night on the behaviour and physiology of animals in the wild, much less is known about the impacts on wild plants and natural or semi-natural vegetation composition. This is surprising, as effects of low-intensity light at night on flowering, phenology and growth form are well known in laboratory and greenhouse studies.In a long-term experimental field study we exposed a semi-natural grassland to artificial light at intensities and wavelengths typical of those experienced by roadside vegetation under street lighting.We found that lighting affected the trajectory of vegetation change, leading to significant differences in biomass and plant cover in the dominant species.Changes in flowering phenology were variable between years, with grass species flowering between 4 days earlier and 12 days later under artificial light.Policy implications. Our results demonstrate that artificial light, at levels equivalent to those in street-lit environments, can affect species composition in semi-natural vegetation. This highlights the importance of considering artificial light as a driver of vegetation change in urban, suburban and semi-natural ecosystems, and where possible, of minimising or excluding artificial light from habitats of conservation importance.
      PubDate: 2017-06-08T05:41:15.183276-05:
      DOI: 10.1111/1365-2664.12927
       
  • Land use history and seed dispersal drive divergent plant community
           assembly patterns in urban vacant lots
    • Authors: Anna L. Johnson; Dorothy Borowy, Christopher M. Swan
      Pages: 451 - 460
      Abstract: Despite high levels of disturbance and habitat modification, urban ecosystems still host substantial levels of biodiversity. The processes that maintain existing levels of diversity, however, remain understudied. Identifying the links between urban ecological processes and patterns has, therefore, become a fundamental research goal to support urban biodiversity and ecosystem functioning.We conducted a study to determine how the diversity and composition of urban plant communities is affected by spatially and temporally variable land use legacies. We constructed a chronosequence of vacant lot properties covering a range of 3–22 years since demolition, in an urban neighbourhood in Baltimore, Maryland (USA). Surveys of herbaceous plant species abundance were conducted during the summers of 2012 and 2013 in sections of each vacant lot where the building previously stood (the “building footprint”) and sections of the lot that was previously a backyard or garden (the “remnant garden”).We found divergent patterns in plant community composition between areas of vacant lots with varying land use histories. This includes significant shifts in the functional composition of biotically vectored seed dispersal strategies, as well as an increase in seed mass and terminal velocity trait values of plant communities in building footprints over time. In addition, we found that plant communities in different sections of the same vacant lot tended to become more functionally dissimilar in seed dispersal strategies over time. In contrast, we found no significant changes in taxonomic diversity over time for any of our measures.Policy implications. Our study suggests that regional-scale patterns of seed dispersal interact with diverse land use legacies to structure the plant communities of urban vacant lots. Although it has been suggested that highly altered local environmental conditions and competition from introduced species limit native plant diversity in urban environments, we find seed dispersal to be a more significant driver of urban plant community assembly patterns. Implementing management strategies that focus on habitat connectivity and enhancing species pools via seeding may present an effective strategy for promoting more successful establishment of diverse plant communities in urban environments.
      PubDate: 2017-07-21T07:01:39.750175-05:
      DOI: 10.1111/1365-2664.12958
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.196.215.69
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-