 Subjects -> CONSERVATION (Total: 128 journals)
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- Coevolutionary analysis of the Philopteroides Mey, 2004 (Phthiraptera:
Ischnocera) parasitizing bulbuls (Passeriformes:
Pycnonotidae)|Introduction|Methods|Results|Discussion
Authors: Mengjiao Ren, Daniel R. Gustafsson, Chunpo Tian, Alexandra A. Grossi, Zhixiao Liu, Fasheng Zou
Abstract: IntroductionAvian head lice comprise a diverse group of distantly related genera of lice that exhibit a strongly convergent morphology. Due to their lack of free-living stages, their strong morphological adaptations to living on the host’s head, and the limited opportunities for transfer between hosts during mating or nesting, the lateral transmission of head lice between non-conspecific hosts may be presumed to be restricted. Despite this, many species of head lice are ostensibly host generalists. We here examine lice of the head louse genus Philopteroides Mey, 2004, from bulbuls (Passeriformes: Pycnonotidae).MethodsWe use two different methods, ParaFit and Jane, to get insights on the co-evolutionary history of Philopteroides species and their bulbul hosts. Jane was run with a variation of event costs.ResultsOur phylogenetic analysis indicate that several morphologically cryptic species can be found in this group, most of which appear to be host specific. However, co-phylogenetic analyses indicate that host-switching has been common in the history of these lice, and co-speciation events have been rarer than expected. Moreover, lowest-cost co-evolutionary reconstructions under a variety of event costs are indistinguishable from random. An expanded dataset with more Philopterus-complex lice was found to be evenly balanced between host-switching and co-speciation events.DiscussionThe transfer of avian head lice between host species is poorly understood, but evidently fairly common. Several potential routes are discussed, but direct evidence is missing. Potentially, the presence of multiple bulbul species at fruiting trees may be an important factor in this transfer. However, such transfer routes also do not explain why Philopteroides lice on bulbuls appear to be distinct from those of other hosts. Moreover, as many of the species recovered in our analysis are morphologically indistinguishable, cryptic speciation appears to be common in this group.
PubDate: 2023-03-24T00:00:00Z
- Impacts of high temperature during early capped brood on pupal development
and the size of appendages in adult workers Apis cerana
Authors: Xinjian Xu, Xia Du, Shujing Zhou, Bingfeng Zhou, Kang Lai, Qing Wang, Han Li, Chenyu Zhu, Hongzhi Xu, Xianlan Zhang, Mingjie Cao, Xiangjie Zhu
Abstract: Whether the development of honeybee broods is healthy or not determines the productivity of bee colonies. Pupation is a critical period in the development of holometabolous insects, characterized by the transition from larva to pupa, and its sensitivity to high temperature was investigated in Apis cerana worker bees. Mature larvae (ML), the first and second days of prepupa (PP1 and PP2), and the first day of pupa (P1) were exposed to 40°C for varied durations of time. The mortality, development duration, birth weight, size of the body, and appendages of eclosed Apis cerana worker bees were measured. Results showed that PP1 had the highest mortality, the lowest birth weight, and the longest development duration among the pupation stages. When exposed to 40°C for 12 h and 16 h, more than 28 and 84% of PP1 failed to complete development, respectively. Additionally, high-temperature treatment had a significant effect on the length of the proboscis, the size of the forewing, and the size of the hind leg. These findings suggest that ML and PP1 are crucial checkpoints for wing and appendage (proboscis and legs) development and provide insights into the mechanisms of honeybee brood susceptibility to high-temperature stress in the context of global warming.
PubDate: 2023-03-24T00:00:00Z
- Changes in functional traits and diversity of typical alpine grasslands
after a short-term trampling disturbance
Authors: Wei Li, Ting Dan Zheng, Xi Ping Cheng, Shu Qiang He
Abstract: Alpine grassland ecosystem supports high diversity of terrestrial flora and fauna species. Despite the ecological importance and economic potential of this unique ecosystem type, it experiences increasing anthropogenic disturbances such as trampling, which impose negative impact on the health and integrity of alpine grasslands. Previous studies of trampling impact on alpine vegetation mainly focus on changes in vegetation cover and taxonomic diversity after trampling disturbance, but rarely test community-level responses of alpine vegetation to trampling from a functional trait perspective. Through the lens of vegetation functional traits, the present study evaluates the impacts of simulated trampling on typical alpine grasslands in Shangri-la, China. The results showed that although increased trampling intensity did not always lead to changes in functional diversity across all three experimental sites, characteristics of community-weighted mean trait values had consistently changed toward plant species with shorter height, reduced leaf area and lower leaf dry matter content, and such strong shifts in functional attributes may further affect ecosystem goods and services provided by alpine grasslands. Therefore, a functional trait approach can help us better understand the mechanisms that drive trait changes, function shifts and vegetation stability following anthropogenic disturbances.
PubDate: 2023-03-24T00:00:00Z
- Floral and genetic divergence across environmental gradients is moderated
by inter-population gene flow in Platanthera dilatata (Orchidaceae)
Authors: Lisa E. Wallace, Marlin L. Bowles
Abstract: Understanding how natural selection acts on intraspecific variation to bring about phenotypic divergence is critical to understanding processes of evolutionary diversification. The orchid family is well known for pollinator-mediated selection of floral phenotypes operating among species and along environmental or geographic gradients. Its effectiveness at small spatial scales is less understood, making the geographic scale at which intraspecific floral variation is examined important to evaluating causes of phenotypic divergence. In this study, we quantified phenotypic variation in the orchid Platanthera dilatata across 26 populations in coastal Southeast Alaska and compared this to edaphic and genetic variation at microsatellite loci. We sought to determine (1) if flower morphological variation is structured at smaller geographic scales, (2) the extent of genetic divergence in relation to phenotypic divergence, (3) the scale at which inter-population gene flow occurs, and (4) the relative importance of geographic distance and abiotic factors on population genetic structure. Two morphological groups were found to separate based on lip and spur length and are restricted to different habitats. Small-flowered forms occur in muskeg bogs, whereas large-flowered forms occur in fens and meadows, and rarely in sub-alpine habitat. Genetic analyses were concordant with the morphological clusters, except for four small-flowered populations that were genetically indistinguishable from large-flowered populations and considered to be introgressed. In fact, most populations exhibited some admixture, indicating incomplete reproductive isolation between the flower forms. Pollinators may partition phenotypes but also facilitate gene flow because short-tongued Noctuidae moths pollinate both phenotypes, but longer-tongued hawkmoths were only observed pollinating the large-flowered phenotype, which may strengthen phenotypic divergence. Nevertheless, pollinator movement between habitats could have lasting effects on neutral genetic variation. At this small spatial scale, population genetic structure is only associated with environmental distance, likely due to extensive seed and pollinator movement. While this study corroborates previous findings of cryptic genetic lineages and phenotypic divergence in P. dilatata, the small scale of examination provided greater understanding of the factors that may underlie divergence.
PubDate: 2023-03-24T00:00:00Z
- Evidencing success: Data requirements to model the impacts of long-term
management of invasive squirrels
Authors: Zelda van der Waal, Aileen C. Mill
Abstract: Established widespread populations of invasive vertebrates can be challenging to eradicate and for small to medium-sized vertebrates, such as squirrels, is often not deemed feasible. However, long-term trapping campaigns are necessary to limit spread or reduce impacts. The scale of trapping programmes is often limited by budgets that are not commensurate to the scale of the problem. On-going costs and fundraising are key factors used by decision makers to assess the feasibility of complete removal or long-term management options of established populations. Predicting the time and effort required to successfully manage Invasive Alien Species (IAS) remains a challenge, particularly where different strategies need to be employed across different spatial scales and habitat types, and in response to changing population densities. Statistical methods such as removal models can be applied to quantify population abundance during management operations and could inform planning of resource requirements. However, in practice, the lack of awareness of data requirements results in unsuited or non-standardized data collection. We present data from an invasive grey squirrel (Sciurus carolinensis) management project in the United Kingdom as a case study to illustrate common issues that impact on quantifying project outcomes. We focus on human and operational aspects of implementation and suggest ways of prioritizing analytical requirements. Insights consider conservation targets, data collection and operational design and may be of relevance to stakeholders, analysts, field operators and managers.
PubDate: 2023-03-24T00:00:00Z
- Smart digital platforms for carbon neutral management and services:
Business models based on ITU standards for green digital transformation
Authors: Han-Teng Liao, Chung-Lien Pan, Yuan Zhang
Abstract: This brief research report focuses on the effects of artificial intelligence (AI) on the environment, by analyzing the latest documents issued by major standard organizations such as the International Telecommunication Union (ITU) and the Internet Society of China (ISC). By outlining the latest developments into a platform canvas for carbon neutrality management and services, this report identifies the potential of “AI of the environment” (i.e., the material composition and environmental impact of AI itself) and “AI for the environment” (i.e., the purposeful use of smart applications to benefit the environment). The role of AI is contextualized in the digital platform design for the provision of services on carbon emission data, which serves as the material foundation for smart services facing both the producers and the consumers of such information. Contributing to the design of business models that enable open innovations, this report discusses the emission impact reduction mechanisms that can optimize, substitute, induce, manage, and facilitate processes and services, indicating the potential of AI-enabled smart services such as forecasting, planning, and recommendation systems. Despite the limited disciplinary considerations and detailed discussions on specific AI technologies, this report provides a simple, practical, and flexible technology roadmap that can be used as a guide for researchers and practitioners to refine their operations and designs and to follow best practices. This report succinctly visualizes key elements of digital platforms of/for GHG emission reduction and their enabling mechanisms, serving as an AI technology roadmap for future research and innovation in the field.
PubDate: 2023-03-23T00:00:00Z
- Outcomes associated with translocation of mule deer (Odocoileus hemionus):
Influence of age, release timing, and year on survival
Authors: David C. Smedley, Brock R. McMillan, Kent R. Hersey, Justin M. Shannon, Randy T. Larsen
Abstract: Translocation of large mammals has become common practice for wildlife managers charged with conservation of animals and their genetic integrity on increasingly modified landscapes. Translocations of ungulates have occurred around the world with varying outcomes. Although translocations have been used to manage mule deer (Odocoileus hemionus) in western North America, only recently have the outcomes associated with this management practice been documented. Our objective was to evaluate survival of translocated mule deer in comparison to resident mule deer over multiple years following release and provide information useful in judging the relative value of translocation as a conservation strategy for this species. In January and March 2013, the Utah Division of Wildlife Resources (UDWR) captured and translocated 102 mule deer from winter range near Parowan, Utah to winter range near Holden, Utah (approximately 145 kilometers north of capture location). We fitted each deer with a radio transmitter (n = 102 total: 21 GPS collars, 81 VHF collars) prior to release. We also captured and marked a total of 70 resident deer (9 GPS collars, 61 VHF collars) to serve as a reference group. Survival of translocated deer in the first year was similar among release dates in January (0.51; 95% CI = 0.40–0.63) and March (0.53; 95% CI = 0.40–0.66). Annual survival of translocated deer, however, was lower than survival of resident deer (0.83; 95% CI = 0.72–0.90) in the first year after release. During the second year following release, however, survival of translocated animals (0.85; 95% CI = 0.71–0.93) was not different from that of resident deer (0.80; 95% CI = 0.69–0.88). Additionally, age strongly influenced the survival of translocated deer; young deer (e.g., 1.5 year olds) were more than twice as likely as old deer (e.g., 7.5 year olds) to survive the initial year following translocation. These data highlight the need to monitor translocated animals for multiple years following release and suggest that wildlife managers should expect to see higher survival rates during the second year following translocation and higher survival rates in younger deer compared to older deer.
PubDate: 2023-03-23T00:00:00Z
- Ecological aspects of volatile organic compounds emitted by exotic
invasive plants
Authors: Andrea Clavijo McCormick, Evans Effah, Adriana Najar-Rodriguez
Abstract: Exotic invasive plants are present in almost all terrestrial ecosystems. Their spread and ability to colonize new habitats are predicted to increase with human travel, global trade, and climate change. These plants alter the environments they invade in multiple ways, affecting surrounding species. Chemically, invasive plants can modify their environment by releasing secondary metabolites such as root exudates (liquid) or airborne (gaseous) volatile organic compounds (VOCs). The allelopathic effect of invasive species' root exudates is well studied and acknowledged as a trait contributing to invasiveness. However, less is known about the effects of invasive species' VOCs, which are likely to play important ecological roles. Therefore, we conducted a systematic review of the literature during the last decade (2012–2022) to explore what is known about the ecological aspects of VOCs emitted by invasive plants, focusing on the factors affecting their emission (genetic, biotic, and abiotic), and their role on plant-plant and plant-insect interactions. We found 29 studies matching our search criteria. These studies suggest that invasive species are more “chemically diverse” than their native counterparts and have different chemical behavior in native compared to invaded ranges. The studies further highlight that chemical traits are heritable and contribute to invasiveness. Multiple biotic and abiotic factors affecting invasive plants' VOC emission have been explored (e.g., herbivory, soil microorganisms, warming, and CO2). The studies indicate that invasive plants may experience less variation in their VOC emissions in response to environmental change than natives, with trade-offs between growth, reproduction and defense influencing VOC emissions. Regarding the impact on native species and their interactions, the allelopathic role of invasive plants' VOCs on native plants is well documented, consistently showing phytotoxic effects. There is also evidence of their involvement in neighbor detection. While volatile-mediated interactions between invasive plants and native insects remain poorly studied, the existing evidence shows that invasive plant VOCs have the potential to disrupt communication between native plants and insects. But insects also use multiple cues to make foraging/oviposition decisions, compensating for the disruptive effect of invasive plant VOCs. To conclude, we identify knowledge gaps and propose avenues for future research.
PubDate: 2023-03-23T00:00:00Z
- Post-fledging survival of Tengmalm’s owl offspring in boreal forests:
Interactive effects of varying dynamics of main prey and habitat
composition
Authors: Marek Kouba, Luděk Bartoš, Filip Tulis, Michal Ševčík, Simona Sovadinová, Tomáš Bušina, Martin Janouš, Petr Kouba, Jitka Bartošová, Kari Hongisto, Erkki Korpimäki
Abstract: The knowledge about the mortality rate of offspring is crucial for estimating bird population dynamics and conserving species with declining populations. Parents of predatory birds provide food for their offspring during the post-fledging dependency period, which is frequently described as essential due to inexpert flying skills. Using radio telemetry, we studied fledglings’ probability of dying by starvation and predation in Tengmalms’ owls (Aegolius funereus). Nestlings (21 and 39) from 10 and 14 broods in 2019 and 2021, respectively, were equipped with leg-mounted tags and monitored throughout the post-fledging dependency period in west-central Finland. In total, 28 out of 60 fledglings did not survive the post-fledging dependency period (12 died due to starvation, and 16 were predated). The fledglings’ probability of dying by starvation and predation was 3.7 and 2.4 times higher, respectively, in the decreasing (2019) than during the increasing (2021) abundance of main foods (voles), showing that prey availability is essential for survival during the post-fledging dependency period. The probability of starvation increased with augmenting agricultural lands in the home range and increasing precipitation after fledging, which indicated that parent owls avoided hunting in open areas and during rainy nights. The predation rate during the post-fledging dependency period increased with augmenting cover of old-growth forests in the home range. This result suggested that coverage of old-growth forests is nowadays so small in the study area that they act as ecological traps for newly-fledged owlets. The reason is that the main avian enemies of Tengmalm’s owls’ (goshawks and Ural owls) also prefer old-growth forests for breeding and hunting.
PubDate: 2023-03-23T00:00:00Z
- Ecosystem service assessment under ecological restoration programs: A
systematic review of studies from China
Authors: Junyan Liu, Jie Du, Chenfeng Zhang, Jindong Zhang, Hongbo Yang, Marion L. Donald, Yan Wu, Tingfa Dong
Abstract: With a growing body of literature on the topic of ecosystem service (ES), there is an urgent need to summarize ES research in the context of ecological restoration programs (ERPs) in China and identify knowledge gaps for future directions. We conducted a systematic literature review of articles to examine the use of ES approaches for ERP assessments. Our results showed that previous studies mainly focused on the Shaanxi Province, and more than half of the reviewed studies considered no more than three ES types simultaneously. All ES categories were not covered equally; most of the studies focused on provisioning and regulating services, while cultural services have received little attention. Although regional-scale and short-term assessments dominated the reviewed papers, we suggest that multiple temporal and spatial scales for ERP assessments should be given more attention in future work. Moreover, we highlight that an oversimplified land use/land cover (LULC) categorization scheme may potentially lead to inaccuracies and biases in ESs detection under restoration programs. Based on this review, our findings can guide future ERP assessments by using the ES approach. Meanwhile, given the global LULC change brought by the proliferation of plantations under ERPs, our results are also expected to provide a path forward to assess ESs associated with LULC change globally.
PubDate: 2023-03-23T00:00:00Z
- Outer membrane vesicles of Dinoroseobacter shibae transport a volatile
aldehyde
Authors: Diana Koteska, Hui Wang, Irene Wagner-Döbler, Stefan Schulz
Abstract: Outer Membrane Vesicles (OMVs) of the Gram-negative marine bacterium Dinoroseobacter shibae, a member of the Roseobacteraceae, were investigated for the presence of volatile organic compounds (VOCs). Extracts of vesicles were analyzed by gas chromatography/mass spectrometry (GC/MS). In these analyses the short fatty acid (Z)-5-dodecenoic acid (1) and the related, more volatile aldehyde (Z)-5-dodecenal (8) were identified as VOCs of the OMVs. The aldehyde 8 has not yet been reported before from bacteria. Due to their possible function as signaling molecules, both compounds were tested for Quorum Sensing (QS) inhibition in a bioassay against the QS sensor strain Pseudomonas putida F117 (pKRC12) responsive to long-chain N-acylhomoserine lactones, the effectors of the sensor. Both compounds showed QS inhibitory activity. The potential function of VOCs in OMVs which has not been observed previously is discussed.
PubDate: 2023-03-23T00:00:00Z
- The devil is in the details: Problems in DNA barcoding practices indicated
by systematic evaluation of insect barcodes
Authors: Zhentao Cheng, Qiang Li, Jun Deng, Qian Liu, Xiaolei Huang
Abstract: In recent years, DNA barcoding has rapidly developed as a powerful tool in taxonomy, demonstrating its value in species identification and discovery of cryptic diversity. The number of barcoding sequences of various species continues to grow in the GenBank and BOLD databases; however, the accuracy of sequences and related raw information in public repositories is often questionable. In the present study, based on a dataset of 68,089 Hemiptera COI barcode sequences covering 3,064 species, 1,072 genera, and 48 families, we analyzed genetic differences within and between species and evaluated possible data errors in the insect barcodes. The results showed that errors in the barcode data are not rare, and most of them are due to human errors, such as specimen misidentification, sample confusion, and contamination. A significant portion of these errors can be attributed to inappropriate and imprecise practices in the DNA barcoding workflow. Herein, suggestions are provided to improve the practical operations and workflow of DNA barcoding to reduce human errors.
PubDate: 2023-03-23T00:00:00Z
- The first fossil seed of Ampelopsis (Vitaceae) in South China
Authors: Helanlin Xiang, Xinkai Wu, Xiaoyan Liu, Shenglan Xu, Jianhua Jin, Luliang Huang
Abstract: Ampelopsis Michx. (Vitaceae) contains more than 30 species and is discontinuously distributed in Eurasia, North America, and Central America. China hosts an abundance of Ampelopsis species. Until now, fossil records of Ampelopsis have been reported only from the Paleocene to the Pleistocene of Europe, the Eocene to the Pliocene of Asia, and the Eocene to the Miocene of North America. Although Ampelopsis is abundant and widespread in China today, no fossils of Ampelopsis have so far been found there, except for fossil seed from the Upper Miocene of Yunnan. In this study, a fossil seed of Ampelopsis japonica (Thunb.) Makino was recovered from the Upper Pleistocene of the Maoming Basin, Guangdong province. It is the first Ampelopsis fossil found in South China. This finding shows that Ampelopsis was distributed in the low latitudes of South China in the Late Pleistocene. Global cooling during the last glaciation might have led to the southward spread of the genus to the low-latitude areas of South China. According to the structural characteristics of our fossil, it is speculated that the aborted ovule, which is common in the fruits of extant Ampelopsis, existed in this genus in the Late Pleistocene.
PubDate: 2023-03-22T00:00:00Z
- Climate change, environmental regulations, and firms' efforts to reduce
pollutant emissions
Authors: Zehua Xiao, Cheng Cai, Lumeng Wang, Yigeng Ma
Abstract: Environmental regulation is an important tool for achieving environmental protection. This study investigated how climate change affects firms' actions to reduce pollutant emissions through environmental regulations. We conducted a pooled OLS regression analysis using data from Chinese industrial firms that were above the designated size from 2006 to 2013. The results showed that firms reduce SO2 emissions in response to climate change, particularly when environmental regulations are more stringent. However, firms prefer to reduce productivity and implement “end-of-pipe” interventions than engage in more green innovation. Our findings highlight how firms deal with climate change under the pressure of environmental regulations and whether ecological considerations align or conflict with economic goals.
PubDate: 2023-03-22T00:00:00Z
- Interpopulation variation in seed traits of five Polygonaceae
Authors: Arvind Bhatt, Shyam S. Phartyal, L. Felipe Daibes, Xingxing Chen
Abstract: Interpopulation variability in seed traits may drive the regeneration capacity of a species to colonize different environments. In the present study, we evaluated the variation in seed physical traits (mass / size, water imbibition, shape index) and physiological traits (germination) of five Polygonaceae species. Seeds of Polygonum lapathifolium var. salicifolium, P. lapathifolium, Reynoutria japonica, Rumex trisetifer, and R. obtusifolius were collected from two or three populations in Jiujiang, China. Physical seed traits were measured before germination tests conducted under different combinations of light and temperatures. Most species had a significant variation in seed physical and physiological traits, although populations are geographically close. Interpopulation variation in seed traits appeared to be species-specific, with the highest variation for R. japonica and lowest for R. trisetifer seeds. Germination response to temperature and light conditions also varied among species and populations, being mostly inhibited in the dark treatments. The light dependence of germination can be related to the small seed size, except for the round-seeded Rumex, depending on the temperature regime. Optimal temperature ranges mainly varied from 10/20°C to 25/35°C, with significant decreases in germination percentage at both coolest and warmest extremes. Germination requirements seem to be related to altitudinal gradients in populations of P. lapathifolium and R. japonica seeds.
PubDate: 2023-03-22T00:00:00Z
- Effects of photovoltaic power station construction on terrestrial
ecosystems: A meta-analysis
Authors: Yong Zhang, Zhengqing Tian, Benli Liu, Shengyun Chen, Jihua Wu
Abstract: The rapid increase in construction of solar photovoltaic power stations (SPPs) has motivated ecologists to understand how these stations affect terrestrial ecosystems. Comparing study sites, effects are often not consistent, and a more systematic assessment of this topic remains lacking. Here, we evaluated the effects of SPP construction on carbon emissions, edaphic variables, microclimatic factors and vegetation characteristics in a meta-analysis. We employed log response ratios (as effect sizes) to assess how control plots differed from those beneath solar photovoltaic panels. We found that SPP construction decreased the local air temperature and photosynthetically active radiation, while increasing air humidity, especially in grasslands. Furthermore, plant aboveground biomass and vegetation cover were also enhanced by SPP construction in grassland ecosystems. In farmland ecosystems, photovoltaic panel installation increased plant aboveground biomass, soil available phosphorus and soil pH, while reducing CO2 flux, plant species richness and vegetation cover in woodlands. Thus, while SPP construction had profound ecological impacts in terrestrial ecosystems, the direction and strength of these effects were largely dependent on ecosystem type. Most studies of SPP construction to date have focused on local microclimatic and plant diversity effects, but few studies have examined effects on ecosystem functions and services. Future assessments are needed of both the benefits and disbenefits of SPP construction across different ecosystems, to improve SPP site selection and adaptive management.
PubDate: 2023-03-22T00:00:00Z
- Modeling the effects of spatially explicit patterns of climate and fire on
future populations of a fire-dependent plant
Authors: Gregory A. Backus, Miranda Brooke Rose, Santiago José Elías Velazco, Janet Franklin, Alexandra D. Syphard, Helen M. Regan
Abstract: Many plant species are likely to face population decline or even extinction in the coming century, especially those with a limited distribution and inadequate dispersal relative to the projected rates of climate change. The obligate seeding California endemic, Ceanothus perplexans is especially at risk, and depending on how climate change interacts with altered fire regimes in Southern California, certain populations are likely to be more at risk than others. To identify which areas within the species’ range might need conservation intervention, we modeled population dynamics of C. perplexans under various climate and fire regime change scenarios, focusing on spatially explicit patterns in fire frequency. We used a species distribution model to predict the initial range and potential future habitat, while adapting a density-dependent, stage-structured population model to simulate population dynamics. As a fire-adapted obligate seeder, simulated fire events caused C. perplexans seeds to germinate, but also killed all adults in the population. Our simulations showed that the total population would likely decline under any combination of climate change and fire scenario, with the species faring best at an intermediate fire return interval of around 30–50 years. Nevertheless, while the total population declines least with a 30–50 year fire return interval, the effect of individual subpopulations varies depending on spatially explicit patterns in fire simulations. Though climate change is a greater threat to most subpopulations, increased fire frequencies particularly threatened populations in the northwest of the species’ range closest to human development. Subpopulations in the mountainous southern end of the range are likely to face the sharpest declines regardless of fire. Through a combination of species distribution modeling, fire modeling, and spatially explicit demographic simulations, we can better prepare for targeted conservation management of vulnerable species affected by global change.
PubDate: 2023-03-22T00:00:00Z
- Phylogeographic analysis revealed allopatric distribution pattern and
biogeographic processes of the widespread pale chub Opsariichthys
Authors: Jiaxin Gao, Dan Yu, Huanzhang Liu
Abstract: Understanding phylogeographic patterns of widespread species can provide insights into their speciation processes and guide the conservation and management measures. In the present study, Cyt b sequences were used to investigate the phylogeographic structure of the Opsariichthys acutipinnis-evolans complex in southeastern China. The gene tree revealed six major lineages (lineage A-F) which were distributed allopatrically, with lineage B distributed in the western part (middle Yangtze and Pearl River) and the other lineages in the eastern part (lower Yangtze and coastal waters of southeastern China). Dating of the lineage diversification revealed the early eastward-westward divergence separating lineage A, B, and C during the late Pliocene and early Pleistocene (3.00, 2.61, and 2.12 Ma, respectively), possibly due to the uplift of the Qinghai-Tibetan Plateau and subsequent orogenies in southeastern China. The following northward-southward diversification resulted in the separation of lineage D, E, and F in the early-middle Pleistocene (1.33 and 0.95 Ma), likely associated with the enhanced succession of glacial cycles during the Early-Middle Pleistocene transition. Although the genetic divergence of 0.017–0.070 among lineages indicated possible different species, morphological characters failed to separate them. Therefore, they were treated as a species complex. Given the distinct genetic divergence of the various lineages, they were suggested as different evolutionary significant units.
PubDate: 2023-03-22T00:00:00Z
- The establishment of the national key ecological functional zone and the
county’s ecological green development
Authors: Zhang Rong-bo, Zhong Chang-biao
Abstract: Ecological green development is the development of conforming to nature and promoting the harmonious coexistence of man and nature. As the most basic and supportive grassroots political unit, the county level occupies a special key position in the overall national green development strategy. How to evaluate the ecological green development of the county, protect the green earth, and respond to climate change, have become a new problem facing various countries around the world. To this end, China is determined to implement the establishment of a national key ecological functional zone pilot policy to study its ecological green development from the perspective of the county. Based on the literature review and theoretical mechanism, this paper selects 1997 county-level data indicators in mainland China from 2007 to 2019 to explore the role of the establishment of national key ecological function areas on the ecological green development of counties. The implementation of the national key ecological function zone policy can significantly increase the vegetation normalization index by about 0.035–0.037 units. The implementation of the policy has greatly expanded the capacity and range of above-ground and below-ground biomass. The reduction of large-scale investment by the government, the improvement of quality and efficiency of enterprises in the region, and the increase artificial afforestation are important transmission mechanisms for the implementation of policies to affect the green development of counties. The implementation of the policy has a positive green spillover effect on adjacent areas, which can realize regional coordinated ecological governance. Each additional hectare of artificial afforestation can absorb about 134,800 tons of carbon emissions each year, bringing additional benefits of 730 million yuan. It releases about 98,000 tons of oxygen a year, which can be used for 1.312 billion people for oxygen respiration consumption every year.
PubDate: 2023-03-22T00:00:00Z
- Spatial–temporal pattern of urban ecological construction in the Yellow
River basin and its optimization and promotion
paths|Introduction|Methods|Results|Discussion
Authors: Wang Xiaohui, Che Qian, Wang Longsheng, Li Guangyu, Sun Haiyan, Qin Weishan, Chen Shuang, Yao Shimou, Meng Liwei, Yu Xiaoqian
Abstract: IntroductionUrban ecological instruction is an important method of sustainable development that couples the needs of the population and the environment, thus facilitating high-quality development. This study aimed to transform existing large-scale considerations of ecological urban construction to provide a more grounded evaluation framework. We constructed an integrated framework that considers economic, environmental, social, cultural, and ecological factors and their contribution to urban ecological construction.MethodsWe used methods of subjective and objective empowerment, exploratory spatial data analysis, and the obstacle degree model to explore spatiotemporal variations in urban ecological construction.ResultsOur results showed that: (1) From 2006 to 2018, urban ecological construction in the Yellow River basin (YRB) exhibited a “polycentric” spatial differentiation pattern and a significant, gradually decreasing “center-periphery” spatial distribution trend. (2) High–high areas (with high agglomeration and high urban ecological construction) in the YRB are mainly distributed in Shandong Province and the adjacent regions, whereas low–low areas are mainly distributed in south–central Ningxia Province and southern Gansu Province. (3) Analysis of urban ecological construction characteristics across different city scales, functional types, spatial carriers, and basin locations shows that the urban ecological construction level is directly proportional to the scale of the city. The level of urban ecological construction is relatively higher in the Shandong Peninsula urban agglomeration, in the priority development area of the North China Plain, and in the downstream and right bank of the YRB. Spatial differences are mainly controlled by the net difference between regions from the upstream and midstream scales, as well as intra-regional differences between the left and right banks. (4) Marked differences can be observed in the obstacles to ecological construction in different types of cities.DiscussionTypical barriers in cities in the YRB include the total water resources per capita, energy consumption per unit of GDP, the proportion of research and development investment in fiscal expenditure, the number of books in public libraries per 10,000 people, and land use efficiency. In the future, urban ecological construction should be based on the development conditions of each individual city, and should be improved according to local conditions to achieve the construction high-quality ecological cities.
PubDate: 2023-03-21T00:00:00Z
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