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  Subjects -> LANGUAGE AND LITERATURE (Total: 1624 journals)
    - LANGUAGE AND LITERATURE (580 journals)
    - LANGUAGES (233 journals)
    - LITERARY AND POLITICAL REVIEWS (184 journals)
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LANGUAGE AND LITERATURE (580 journals)                  1 2 3     

Showing 1 - 127 of 127 Journals sorted alphabetically
3L : Language, Linguistics, Literature     Open Access   (Followers: 11)
@nalyses     Open Access   (Followers: 1)
a/b : Auto/Biography Studies : Journal of The Autobiography Society     Hybrid Journal   (Followers: 13)
Abgadiyat     Hybrid Journal   (Followers: 2)
Abusões     Open Access  
Ação Midiática : Estudos em Comunicação, Sociedade e Cultura     Open Access  
ACME : Annali della Facoltà di Studi Umanistici dell'Università degli Studi di Milano     Open Access   (Followers: 1)
Acquisition et interaction en langue étrangère     Open Access   (Followers: 3)
Acta Baltico-Slavica     Open Access   (Followers: 1)
Acta Literaria     Open Access   (Followers: 3)
Acta Neophilologica     Open Access  
AFRREV IJAH : An International Journal of Arts and Humanities     Open Access   (Followers: 2)
Alea : Estudos Neolatinos     Open Access   (Followers: 1)
Aletria : Revista de Estudos de Literatura     Open Access  
Algazarra : Revista do Centro de Pesquisa Comunicação e Cultura : Barroco e Mestiçagem     Open Access  
Alpha (Osorno)     Open Access  
American Book Review     Full-text available via subscription   (Followers: 6)
American Journal of Philology     Full-text available via subscription   (Followers: 5)
American Literary Realism     Full-text available via subscription   (Followers: 6)
American Literature     Full-text available via subscription   (Followers: 23)
Anagramas : Rumbos y Sentidos de la Comunicación     Open Access  
Anales Galdosianos     Full-text available via subscription  
Âncora : Revista Latino-Americana de Jornalismo     Open Access  
andererseits : Yearbook of Transatlantic German Studies     Open Access   (Followers: 3)
Aniki : Revista Portuguesa da Imagem em Movimento     Open Access  
ANTARES (Letras e Humanidades)     Open Access  
Anuari de Filologia. Llengües i Literatures Modernes     Open Access  
Anuário de Literatura     Open Access  
Anuario Lope de Vega. Texto, literatura, cultura     Open Access  
Appalachian Heritage     Full-text available via subscription   (Followers: 5)
Arbitrium     Hybrid Journal   (Followers: 7)
Arcadia - International Journal for Literary Studies     Hybrid Journal   (Followers: 9)
Arethusa     Full-text available via subscription   (Followers: 3)
Argumentation et analyse du discours     Open Access   (Followers: 6)
Arizona Quarterly: A Journal of American Literature, Culture, and Theory     Full-text available via subscription   (Followers: 12)
Ars Aeterna     Open Access  
Artelogie     Open Access   (Followers: 1)
Arthuriana     Full-text available via subscription   (Followers: 5)
Artl@s Bulletin     Open Access   (Followers: 1)
Arts et Savoirs     Open Access  
Asia Minor Studies     Open Access   (Followers: 2)
Atalanta : Revista de las Letras Barrocas     Open Access  
Atalaya     Open Access   (Followers: 1)
Australian Journal of French Studies     Full-text available via subscription   (Followers: 6)
Australian Literary Studies     Full-text available via subscription   (Followers: 5)
Azalea: Journal of Korean Literature & Culture     Full-text available via subscription   (Followers: 4)
Babel     Hybrid Journal   (Followers: 13)
Balkanologie : Revue d'Études Pluridisciplinaires     Open Access   (Followers: 4)
Baltic International Yearbook of Cognition, Logic and Communication     Open Access  
Barnboken : Journal of Children's Literature Research     Open Access   (Followers: 3)
Between     Open Access   (Followers: 1)
Biblioteca Escolar em Revista     Open Access  
Biography     Full-text available via subscription   (Followers: 18)
Black Camera     Full-text available via subscription   (Followers: 6)
Boletim de Pesquisa NELIC     Open Access  
Book History     Full-text available via subscription   (Followers: 124)
Bookbird: A Journal of International Children's Literature     Full-text available via subscription   (Followers: 12)
boundary 2     Full-text available via subscription   (Followers: 14)
Brasiliana - Journal for Brazilian Studies     Open Access   (Followers: 1)
Bronte Studies     Full-text available via subscription   (Followers: 3)
Brookings-Wharton Papers on Financial Services     Full-text available via subscription   (Followers: 3)
Brumal. Revista de investigación sobre lo Fantástico     Open Access  
Bulletin for Spanish and Portuguese Historical Studies     Open Access   (Followers: 9)
Bulletin of the Center for Children's Books     Full-text available via subscription   (Followers: 5)
Bunron : Zeitschrift für literaturwissenschaftliche Japanforschung     Open Access   (Followers: 1)
Byron Journal     Hybrid Journal   (Followers: 1)
Byzantinische Zeitschrift     Hybrid Journal   (Followers: 11)
Byzantion Nea Hellás     Open Access   (Followers: 2)
Caderno de Letras     Open Access  
Caderno Seminal     Open Access  
Cadernos de Letras da UFF     Open Access  
Cahiers Balkaniques     Open Access   (Followers: 2)
Cahiers d'histoire. Revue d'histoire critique     Open Access   (Followers: 12)
Cahiers de civilisation espagnole contemporaine     Open Access   (Followers: 2)
Cahiers de littérature orale     Open Access  
Cahiers de recherches médiévales et humanistes     Open Access   (Followers: 10)
Cahiers du Monde Russe     Open Access   (Followers: 10)
Cahiers d’études italiennes     Open Access   (Followers: 6)
Cahiers franco-canadiens de l'Ouest     Full-text available via subscription   (Followers: 1)
Callaloo     Full-text available via subscription   (Followers: 11)
Cambridge Quarterly     Hybrid Journal   (Followers: 10)
Carnets : Revue électronique d'études françaises     Open Access  
Carte Italiane     Open Access   (Followers: 3)
Catedral Tomada. Revista de crítica literaria latinoamericana     Open Access  
CELEHIS : Revista del Centro de Letras Hispanoamericanas     Open Access  
Cervantes : Bulletin of the Cervantes Society of America     Full-text available via subscription   (Followers: 1)
Ceræ: An Australasian Journal of Medieval and Early Modern Studies     Open Access   (Followers: 1)
Chasqui. Revista Latinoamericana de Comunicación     Open Access  
Children's Literature Association Quarterly     Full-text available via subscription   (Followers: 16)
Chloe: Beihefte zum Daphnis     Full-text available via subscription   (Followers: 4)
Chrétiens et sociétés     Open Access   (Followers: 3)
Cipango     Open Access   (Followers: 3)
Cipango - French Journal of Japanese Studies. English Selection     Open Access   (Followers: 4)
Claraboia     Open Access  
CLCWeb : Comparative Literature and Culture     Open Access   (Followers: 11)
CLEaR     Open Access  
Cognitive Studies : Études cognitives     Open Access  
College Literature     Full-text available via subscription   (Followers: 10)
Colonial Academic Alliance Undergraduate Research Journal     Open Access   (Followers: 2)
Colorado Review     Full-text available via subscription   (Followers: 1)
Comparative Critical Studies     Hybrid Journal   (Followers: 20)
Comparative Literature     Full-text available via subscription   (Followers: 36)
Comparative Literature Studies     Full-text available via subscription   (Followers: 28)
Comparative Mythology     Open Access   (Followers: 3)
Comunicação & Sociedade     Open Access  
Configurations     Full-text available via subscription   (Followers: 5)
Conradiana     Full-text available via subscription   (Followers: 1)
Contemporary Literature     Full-text available via subscription   (Followers: 20)
Contemporary Pacific     Full-text available via subscription   (Followers: 8)
Contemporary Women's Writing     Hybrid Journal   (Followers: 11)
COnTEXTES     Open Access   (Followers: 1)
CR : The New Centennial Review     Full-text available via subscription  
Criticism     Full-text available via subscription   (Followers: 10)
Criticón     Open Access   (Followers: 1)
Critique: Studies in Contemporary Fiction     Full-text available via subscription   (Followers: 8)
Cuadernos AISPI     Open Access  
Cuadernos de Ilustración y Romanticismo     Open Access  
Cuadernos de Rusística Española     Open Access  
Cuadernos LIRICO : Revista de la Red Interuniversitaria de Estudios sobre las Literaturas Rioplatenses Contemporáneas en Francia     Open Access   (Followers: 1)
Cuban Studies     Full-text available via subscription   (Followers: 6)
Cultures et conflits     Open Access   (Followers: 1)
Current Narratives     Open Access   (Followers: 12)
Current Objectives of Postgraduate American Studies     Open Access   (Followers: 1)
Current Writing : Text and Reception in Southern Africa     Hybrid Journal   (Followers: 2)
De Signos y Sentidos     Open Access  
De Zeventiende Eeuw. Cultuur in de Nederlanden in interdisciplinair perspectief     Open Access   (Followers: 2)
Deuterocanonical and Cognate Literature Yearbook     Hybrid Journal  
Dialektika : Jurnal Bahasa, Sastra, dan Pendidikan Bahasa dan Sastra Indonesia     Open Access  
Diálogos Latinoamericanos     Open Access  
Dicenda. Cuadernos de Filología Hispánica     Open Access  
Dickens Quarterly     Full-text available via subscription   (Followers: 1)
Diegesis : Interdisziplinäres E-Journal für Erzählforschung     Open Access  
Discours     Open Access   (Followers: 2)
Dix-Neuf     Hybrid Journal   (Followers: 3)
DQR Studies in Literature     Full-text available via subscription   (Followers: 1)
Drammaturgia     Open Access  
Dublin James Joyce Journal     Full-text available via subscription   (Followers: 1)
Dutch Crossing : Journal of Low Countries Studies     Hybrid Journal   (Followers: 4)
e-Journal of Linguistics     Open Access   (Followers: 1)
E-rea     Open Access   (Followers: 2)
e-Scripta Romanica     Open Access  
e-Spania     Open Access   (Followers: 1)
e-TEALS     Open Access   (Followers: 1)
Early American Literature     Full-text available via subscription   (Followers: 7)
Early Modern Culture Online     Open Access   (Followers: 37)
Ecotone     Full-text available via subscription  
Ecozon@ : European Journal of Literature, Culture and Environment     Open Access   (Followers: 4)
EDGE - A Graduate Journal for German and Scandinavian Studies     Open Access   (Followers: 5)
Educação & Linguagem     Open Access  
Eighteenth-Century Fiction     Full-text available via subscription   (Followers: 19)
Éire-Ireland     Full-text available via subscription   (Followers: 8)
El Hilo de la Fabula     Open Access  
ELH     Full-text available via subscription   (Followers: 17)
ELOPE : English Language Overseas Perspectives and Enquiries     Open Access  
Emily Dickinson Journal     Full-text available via subscription   (Followers: 3)
English in Africa     Full-text available via subscription   (Followers: 2)
English in Aotearoa     Full-text available via subscription   (Followers: 1)
English in Australia     Full-text available via subscription   (Followers: 2)
English in Education     Hybrid Journal   (Followers: 13)
English Literature in Transition 1880-1920     Full-text available via subscription   (Followers: 6)
English Studies in Africa     Hybrid Journal   (Followers: 1)
English Text Construction     Hybrid Journal   (Followers: 7)
English: Journal of the English Association     Hybrid Journal   (Followers: 13)
Enthymema     Open Access  
Entrelaces     Open Access  
Epiphany     Open Access   (Followers: 3)
ESC: English Studies in Canada     Full-text available via subscription   (Followers: 3)
Escritura e Imagen     Open Access   (Followers: 1)
Eslavística Complutense     Open Access   (Followers: 1)
ESQ: A Journal of the American Renaissance     Full-text available via subscription   (Followers: 1)
Essays in Criticism     Hybrid Journal   (Followers: 15)
Essays in French Literature and Culture     Full-text available via subscription   (Followers: 6)
Estudios de Literatura Colombiana     Open Access  
Estudios de Teoría Literaria - Revista digital: artes, letras y humanidades     Open Access  
Estudios Ingleses de la Universidad Complutense     Open Access  
Estudis de Literatura Oral Popular / Studies in Oral Folk Literature     Open Access  
Études canadiennes / Canadian Studies     Open Access   (Followers: 1)
Études de lettres     Open Access   (Followers: 2)
Études Épistémè     Open Access  
Études françaises     Full-text available via subscription   (Followers: 5)
Études littéraires     Full-text available via subscription   (Followers: 5)
Eugene O’Neill Review     Full-text available via subscription  
European Journal of Life Writing     Open Access   (Followers: 5)
European Romantic Review     Hybrid Journal   (Followers: 10)
ExELL : Explorations in English Language and Linguistics     Open Access  
Exercices de Rhétorique     Open Access  
Figurationen     Hybrid Journal   (Followers: 3)
Fólio : Revista de Letras     Open Access  
Fourth Genre: Explorations in Nonfiction     Full-text available via subscription   (Followers: 1)
French Forum     Full-text available via subscription   (Followers: 8)
French Studies in Southern Africa     Full-text available via subscription   (Followers: 1)
FronteiraZ. Revista do Programa de Estudos Pós-Graduados em Literatura e Crítica Literária     Open Access  
Genre     Full-text available via subscription   (Followers: 12)
Genre & histoire     Open Access   (Followers: 4)
George Herbert Journal     Full-text available via subscription  
German Studies Review     Full-text available via subscription   (Followers: 26)
Globe : A Journal of Language, Culture and Communication     Open Access   (Followers: 1)
Goethe Yearbook     Full-text available via subscription   (Followers: 7)
Gothic Studies     Full-text available via subscription   (Followers: 14)
Hardy Review     Full-text available via subscription   (Followers: 1)

        1 2 3     

Journal Cover English in Education
  [SJR: 0.309]   [H-I: 4]   [13 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0425-0494 - ISSN (Online) 1754-8845
   Published by John Wiley and Sons Homepage  [1583 journals]
  • Issue Information
    • Abstract: No abstract is available for this article.
      PubDate: 2017-04-24T05:05:17.592835-05:
      DOI: 10.1002/eco.1783
       
  • Issue Information - Cover
    • PubDate: 2017-04-19T12:14:43.275467-05:
      DOI: 10.1002/etc.3817
       
  • Disrupting Continuities – Re-thinking Conceptions of
           ‘Growth’ in English Teaching
    • Authors: Paul Tarpey
      Abstract: In this piece I explore the concept of ‘growth’ in English teaching. Starting with John Dixon's ‘growth’ model, I argue that, by re-imagining his ideas in current contexts, practitioners might re-focus and re-invigorate the priorities of English teaching. Dominant conceptions of ‘growth’ are explored, along with their influence on teacher working cultures and the speech genres they draw on. I argue that, by critically challenging dominant discourses and cultural perspectives, it is possible to generate new narratives and open up new possibilities for the subject.
      PubDate: 2017-04-17T02:40:31.12431-05:0
      DOI: 10.1111/eie.12129
       
  • In situ monitoring of H and O stable isotopes in soil water reveals
           ecohydrologic dynamics in managed soil systems
    • Authors: Erik J. Oerter; Gabriel Bowen
      Abstract: The water cycle in urban and hydrologically managed settings is subject to perturbations that are dynamic on small spatial and temporal scales; the effects of which may be especially profound in soils. We deploy a membrane inlet-based laser spectroscopy system in conjunction with soil moisture and temperature sensors to monitor soil water dynamics and H and O stable isotope ratios (δ2H and δ18O values) in a seasonally irrigated urban-landscaped garden soil over the course of 9 months between the cessation of irrigation in the autumn and the onset of irrigation through the summer. We find that soil water δ2H and δ18O values predominately reflect seasonal precipitation and irrigation inputs. A comparison of total soil water by cryogenic extraction and mobile soil water measured by in situ water vapor probes reveals that initial infiltration events after long periods of soil drying (the autumn season in this case) emplace water into the soil matrix that is not easily replaced by, or mixed with, successive pulses of infiltrating soil water. Tree stem xylem water H and O stable isotope composition did not match that of available water sources. These findings suggest that partitioning of soil water into mobile and immobile “pools” and resulting ecohydrologic separation may occur in engineered and hydrologically managed soils and not be limited to natural settings. The laser spectroscopy method detailed here has potential to yield insights in a variety of critical zone and vadose zone studies, potential that is heightened by the simplicity and portability of the system.HighlightsWe develop a lightweight field deployable isotope ratio infrared spectroscopy system for measuring in situ soil water δ2H and δ18O values.Seasonal soil water δ2H and δ18O values respond to precipitation and irrigation inputs.Ecohydrologic separation between irrigation and precipitation and soil and plant stem water can occur in irrigated ecosystems.It may be possible to couple water vapor probe measurements to that of extracted water to characterize the isotopic composition of the various pools of water in soil.
      PubDate: 2017-04-12T03:12:30.984863-05:
      DOI: 10.1002/eco.1841
       
  • Experimental variations in functional and demographic traits of Lappula
           semiglabra among dew amount treatments in an arid region
    • Authors: Xiao-Dong Yang; Guang-Hui Lv, Arshad Ali, Qi-Yang Ran, Xue-Wei Gong, Fei Wang, Zhi-Dong Liu, Lu Qin, Wei-Guo Liu
      Abstract: In an arid region, water is the limiting factor for the performance of plants and, hence, the input of water significantly affects the ecological processes. Although the dew phenomenon often occurs in the desert, whether plants can absorb and utilise this water source is still unknown. In this study, we tested the effects of 3 amounts of dew, that is, total natural amount of dew, half amount of natural dew, and no amount of (zero) dew, in order to investigate variations in functional traits and demographic traits in relation to the life history of an ephemeral plant Lappula semiglabra. Results showed that variations in functional traits including plant height, crown area, leaf area, leaf thickness, leaf relative water content, chlorophyll content, and net photosynthetic rate were significantly increased with increasing dew amount. Leaf water potential was significantly decreased, whereas root length and root diameter showed no significant differences among 3 amounts of dew. Demographic traits including survival rate, survival, total age, and mean life expectancy increased with increasing dew amount, whereas the vanish rate percentage, mortality rate, mortality, and fatal number decreased. In combination, our results showed that leaf and stem traits L. semiglabra related to dew absorption increased with increasing of dew amount, and hence, obtained more water, whereas root traits related to uptake of soil water remain unchanged. We conclude that leaves and stem of L. semiglabra can absorb and efficiently utilise dew as a water resource for better suitability in the arid desert region.
      PubDate: 2017-04-12T03:12:19.151707-05:
      DOI: 10.1002/eco.1858
       
  • Does reintroducing large wood influence the hydraulic landscape of a
           lowland river at multiple discharges?
    • Authors: Adrian Matheson; Martin Thoms, Mark Southwell, Michael Reid
      Abstract: Large wood is a key structural and functional component of rivers, and it is reintroduced to provide physical habitat, encourage channel stability, and influence in-channel hydraulic conditions at a range of scales. Typically, studies assessing the influence of reintroduced wood on in-channel hydraulic character have been undertaken at relatively small scales—at a site. Relatively little is known about how reintroduced wood influences in-channel hydraulic character at larger reach scales and over different discharges. In this study, the hydraulic character or hydraulic landscape of multiple reference (wooded), control (unwooded), and managed (wood reintroduced) reaches (average length = 430 m) at 10 different discharges in the Barwon-Darling River, Australia, were analysed. Landscape scale hydraulic character was compared using spatial metrics describing the size, shape, and relative location of hydraulic patches in each reach. It was hypothesised that reintroducing wood would significantly influence hydraulic landscapes within the managed reaches, with those reaches becoming more similar to reference reaches. The reintroduction of wood into the Barwon-Darling River did not significantly influence the hydraulic landscapes of the managed reaches; instead, they remained more similar to control reaches across discharges. Discharge did significantly influence the hydraulic landscape, with stepwise changes in the character of the hydraulic landscape in response to increasing discharge. The limited influence of reintroduced wood on the hydraulic landscapes is hypothesised to be because reintroduced wood did not match naturally occurring wood in terms of the character of individual pieces or their spatial distribution within the reach.
      PubDate: 2017-04-12T03:12:11.298182-05:
      DOI: 10.1002/eco.1854
       
  • Conductive sapwood area prediction from stem and canopy areas—allometric
           equations of Kalahari trees, Botswana
    • Authors: Maciek W. Lubczynski; Diana C. Chavarro-Rincon, David G. Rossiter
      Abstract: Conductive sapwood (xylem) area (Ax) of all trees in a given forested area is the main factor contributing to spatial tree transpiration. One hundred ninety-five trees of 9 species in the Kalahari region of Botswana were felled, stained, cut into discs, and measured to develop allometric equations predicting Ax from estimates of stem (As) and canopy (Ac) areas. Stem discs were also subjected to laboratory-based computed tomography, which well detected wood density contrasts but was not diagnostic with regard to delineation of Ax. The staining experiment, along with the help of visual and computed tomography analysis, allowed the definition of 4, tree-species categories of Ax, C1–C4. In C1 (Acacia erioloba, Terminalia sericea, and Burke Africana), the staining and visual delineation of Ax matched the natural color difference between sapwood and heartwood; in C2 (Dichrostachys cinerea and Ochna pulchra), sapwood was divided into external conductive and internal nonconductive annuli; in C3 (Acacia fleckii and Acacia luederitzii), sapwood had sharp staining boundary between external highly conductive and internal low-conductive annuli; and in C4 (Lonchocarpus nelsii and Boscia albitrunca), stems had no heartwood. Per-species 0-intercept linear regression models, Ax = slope.As (slope = 0.392 ÷ 0.794; R2 = 96.7 ÷ 99.8%) and Ax = slope.Ac (slope = 1.477 ÷ 17.044; R2 = 82.1 ÷ 92.2%) yielded excellent to good predictive allometric equations. The first equation is suitable for Ax scaling of small-size Kalahari areas, where the As of all trees can be estimated on the ground, whereas the second, as contribution to automated tree transpiration mapping of large-size Kalahari areas, where the Ac of trees can be derived through remote sensing interpretation of high-resolution images.
      PubDate: 2017-04-12T03:08:19.355786-05:
      DOI: 10.1002/eco.1856
       
  • Environmental watering for vegetation diversity outcomes must account for
           local canopy conditions
    • Authors: Samantha J. Capon; Stephen R. Balcombe, James McBroom
      Abstract: Hydrology is widely considered to be the dominant driver of understorey vegetation dynamics in arid and semiarid riparian ecosystems. Consequently, environmental watering is often a key approach to restoring and promoting riparian vegetation diversity. Few studies however have considered the role of local factors, for example, shading or litter accumulation, on vegetation responses to flow and how these may influence the outcomes of watering actions. Knowledge concerning modifying effects of local canopy factors on vegetation responses to watering is needed to guide environmental water planning (e.g., setting objectives and targets) and delivery (e.g., timing and duration of managed flows). We conducted a greenhouse experiment to investigate the effects of shade and litter, and their interaction, on plant communities establishing from riparian soil seed banks, collected from the northern Murray–Darling Basin, under a range of hydrological conditions. We found that shade had a positive influence on the abundance, diversity, and reproduction of establishing plant communities under dry conditions but a negative, or null effect, under wet conditions. Litter exerted strong negative effects on plant community metrics under all hydrological conditions. Some understorey species emerged as hardy generalists capable of establishment under a range of conditions whereas others had more specific requirements. Our results highlight the importance of canopy structure for riparian understorey vegetation diversity and dynamics at both local and landscape scales. Land and water management practices seeking to protect or restore vegetation diversity in these systems must therefore take such local factors into account when planning and evaluating interventions.
      PubDate: 2017-04-12T03:01:28.044218-05:
      DOI: 10.1002/eco.1859
       
  • Crack willow changing riverine landscapes in Patagonia
    • Authors: L. Datri; A. Faggi, L. Gallo
      Abstract: In Patagonia (Argentina) in recent decades, the exotic species and hybrids of Salix alba–Salix fragilis complex has spread over wide areas along watercourses, taking advantage of it is sexually and vegetatively propagation. It outcompetes with native vegetation, facilitated by stochastic events related to large floods of long-lasting duration higher than the average maximum of 186 m3/s for more than a day. We analysed the exotic willow's increase along the braiding Azul River, and the hydrological regime between 1966 and 2012. We evaluated the links between regime and tree density over time using dendrochronological data. Results showed an increase of the forest's cover from 2.1% to 70.8% over the last 46 years. The densities of exotic willows grew exponentially between 1966 and 1973, during a period which was free of higher floods. The initial native populations declined as willow's population increased. Up to 1973, there was an increase in the native populations too. Then from 1974 on, the willow showed a gradual growth coupled with a decline in the native trees. Up to 1977, the willow expansion could be linked to an extreme flood that reached 392 m3/s (210.75%) greater than the average of the maximum flows). We concluded that plant succession in the Azul River follows a “Red Queen” effect whereby the exotic willow and native trees repeatedly reorganized the system after pulses and periods of extreme flooding events.
      PubDate: 2017-04-06T20:56:08.493201-05:
      DOI: 10.1002/eco.1837
       
  • Helophyte impacts on the response of hyporheic invertebrate communities to
           inundation events in intermittent streams
    • Authors: Viktor Baranov; Djuradj Milošević, Marie J. Kurz, Jay P. Zarnetske, Francesc Sabater, Eugenia Marti, Anne Robertson, Tanja Brandt, Albert Sorolla, Jörg Lewandowski, Stefan Krause
      Abstract: The effects of experimental inundation on invertebrate communities in artificial flumes fed with treated wastewater were investigated. Flumes, designed to simulate intermittent river conditions, were planted with 3 species of helophytes widely used in river restoration around the water-stressed regions of Europe. Different species of vegetation had different capabilities to reduce the invertebrate's negative reaction to inundation, related mostly to rhizosphere density. Of the 3 helophyte species tested, only 1, Lysimachia vulgaris, showed significant capabilities to reduce invertebrate negative reaction on inundation. Species richness of invertebrates before and after the inundation did not change in any of the flumes, whereas species density significantly declined in all flumes except one planted with L. vulgaris. This helophyte species was associated with high densities of the Culicidae larvae (common mosquitos), which has severe implications for river restoration and vector management in the region. This study indicates that the selection and establishment of different helophyte species will impact invertebrate communities in restored streams, especially streams experiencing variable inundation conditions.
      PubDate: 2017-04-06T20:56:00.406114-05:
      DOI: 10.1002/eco.1857
       
  • Forest cover change and water yield in large forested watersheds: A global
           synthetic assessment
    • Authors: Qiang Li; Xiaohua Wei, Mingfang Zhang, Wenfei Liu, Houbao Fan, Guoyi Zhou, Krysta Giles-Hansen, Shirong Liu, Yi Wang
      Abstract: The effects of forest cover change on water yield have long been studied across the globe. Several reviews have summarized the impacts of forest change and water yield from the small and paired watershed experiments, but no any synthetic assessment has been conducted on the basis of studies of large watersheds (>1,000 km2). We conducted a synthetic analysis on the basis of the studies from 162 large studied watersheds across the globe to explore how forest cover change affects annual water yield. Our first-ever assessment confirms that deforestation increases annual water yield and reforestation decreases it, which is consistent with results from paired watershed experiments. More importantly, we found that forest cover and climate variability play a coequal role in annual water yield variations. The effects of forest cover change and climate variability on annual water yield variations can be additive or offsetting. Thus, their interactions can critically determine the magnitudes and directions of water yield changes. We also found that the hydrological sensitivities to forest cover change in smaller and dryer watersheds are higher than those in larger and wetter ones. The implications of these findings for sustainable water and watershed management are discussed in the context of future land cover and climate changes.
      PubDate: 2017-04-06T20:55:47.739928-05:
      DOI: 10.1002/eco.1838
       
  • Riparian plant composition along hydrologic gradients in a dryland river
           basin and implications for a warming climate
    • Authors: Lindsay V. Reynolds; Patrick B. Shafroth
      Abstract: Droughts in dryland regions on all continents are expected to increase in severity and duration under future climate projections. In dryland regions it is likely that minimum streamflow will decrease with some perennial streams shifting to intermittent flow under climate-driven changes in precipitation and runoff and increases in temperature. Decreasing base flow and shifting flow regimes from perennial to intermittent could have significant implications for stream-dependent biota, including riparian vegetation. In this study, we asked, how do riparian plant communities vary along wet-to-dry hydrologic gradients on small (1st-3rd order) streams? We collected data on geomorphic, hydrologic, and plant community characteristics on 54 stream sites ranging in hydrology from intermittent to perennial flow across the Upper Colorado River Basin (UCRB, 284,898 km2). We found that plant communities varied along hydrologic gradients from high to low elevation between streams, and perennial to intermittent flow. We identified indicator species associated with different hydrologic conditions and suggest how plant communities may shift under warmer, drier conditions. Our results also indicate that species richness and cover of total, perennial, wetland, and native plant groups will decrease while annual plants will increase under drying conditions. Understanding how plant communities respond to regional drivers such as hydroclimate requires broad-scale approaches such as sampling across whole river basins. With increasingly arid conditions in many regions of the globe, understanding plant community shifts is key to understanding the future of riparian ecosystems.
      PubDate: 2017-04-03T21:40:52.341713-05:
      DOI: 10.1002/eco.1864
       
  • Estimating regional losses of soil water due to the conversion of
           agricultural land to forest in China's Loess Plateau
    • Authors: Xiaoxu Jia; Yunqiang Wang, Ming'an Shao, Yi Luo, Chencheng Zhang
      Abstract: Afforestation on the Chinese Loess Plateau (CLP) has been extensively implemented by the central government over the past decades to control soil erosion. The conversion of agricultural land to forest, however, has led to decreases in soil-water storage (SWS), which may in turn limit tree growth and threaten the health of ecosystems in the region. This study estimated the regional patterns of losses of soil water (ΔSWS) following conversions across the CLP. Soil-water content at 0–5.0 m was measured in 169 forests on the plateau, and the initial preafforestation SWS at each sample site was then estimated using stepwise regression. The mean ΔSWS in the 1.0- to 5.0-m profile across the study area was 203.7 mm, with an estimated annual average ΔSWS rate of 16.2 mm/year. ΔSWS and its main contributing factors varied amongst 3 rainfall zones. ΔSWS generally increased with mean annual precipitation (MAP). ΔSWS depended primarily on tree age in the >550 mm MAP zone and on slope gradient and initial SWS in the
      PubDate: 2017-03-31T06:10:54.463196-05:
      DOI: 10.1002/eco.1851
       
  • Organic sediment pulses impact rivers across multiple levels of ecological
           organization
    • Authors: Katie L. Aspray; Joseph Holden, Mark E. Ledger, Chris P. Mainstone, Lee E. Brown
      Abstract: Sedimentation is a pervasive environmental pressure affecting rivers globally. Headwaters draining catchments rich in organic soils (i.e., peat) are particularly vulnerable to enhanced sedimentation caused by land management and environmental change, yet many of the ecological consequences of peat deposition are poorly understood. We conducted a before-after-control-impact experiment in two rivers draining blanket peatland in Northern England to test the effect of sediment inputs on water quality, macroinvertebrate drift, macroinvertebrate community structure, and ecosystem metabolism. Sediment addition increased concentrations of dissolved organic carbon, total oxidised nitrogen and suspended sediment concentration in rivers, and intensified the total drift of macroinvertebrates particularly at night. By contrast, the abundance and richness of benthic macroinvertebrates were unaffected, except for declines in Coleoptera abundance in one river. The gross primary production of both rivers was strongly suppressed as the benthos was smothered by sediment. Community respiration also declined, albeit by different extents in the two rivers. Our experiment revealed that short-term pulses of organic sediment in rivers can have broad effects on water quality and biota, from influences on the dispersal of individual organisms to the modification of ecosystem processes. Organic sediments therefore warrant further examination, to include longer observation periods and more sites. It is particularly important to clarify the extent to which impacts extend from peatland streams into larger rivers downstream. Such studies are necessary to inform global management efforts to restore the integrity of river ecosystems under a range of water and biodiversity policy mechanisms.
      PubDate: 2017-03-31T06:10:45.984167-05:
      DOI: 10.1002/eco.1855
       
  • Coupled geomorphic and habitat response to a flood pulse revealed by
           remote sensing
    • Authors: Lee R. Harrison; Andrew Pike, David A. Boughton
      Abstract: Despite a growing consensus on the importance of floods in structuring river ecosystems, predicting the geomorphic and habitat response to specific flood pulses across a range of scales remains challenging. We used a large reservoir release in a semiarid river to characterize geomorphic and habitat responses to a flood pulse, using an integrated field, remote sensing, and modeling approach. Large-scale geomorphic changes were observed as a result of the flood, including lateral migration of the river channel, gravel bar formation, and development of off-channel chutes. Spatial patterns of gravel storage varied with downstream distance from a large dam, with the upper 15 km experiencing a net sediment deficit and the lower 65 km undergoing net deposition. The longitudinal trends in gravel transport and storage reflected differences in channel gradient and predicted values of sediment mobility. The flood lowered the channel by an average of −0.5 m and roughly doubled the areal extent of pools, by incising new pools in curved reaches and in areas where the river abutted valley walls and terraces. The increased pool abundance provided greater habitat connectivity and was predicted to have positive impacts on anadromous steelhead, providing up to a 3-fold increase in the number of juvenile fish the river could support. Results from this study highlight the value of using flood pulses as opportunities to learn about river behavior, and for testing the degree to which physical processes can help restore the form and function of river ecosystems.
      PubDate: 2017-03-31T06:10:38.034792-05:
      DOI: 10.1002/eco.1845
       
  • Temperature rise may explain grass depletion in the Chihuahuan Desert
    • Authors: Giora J. Kidron; Vincent P. Gutschick
      Abstract: A consistent encroachment of shrubs into the northern Chihuahuan Desert (NM, USA) has been well documented since the mid-1800s. This phenomenon is mainly attributed to overgrazing followed by nutrient depletion, which impedes successful grass establishment. Significantly, higher grass cover that were measured by us during 1998 and 2005 in plots at the Sevilleta National Wildlife Refuge, SEV (60.5–62%), than in plots at the Jornada Experimental Range, JER (4.7–4.9%), lead us to hypothesize that climatological factors that may affect soil moisture may account for the differences in grass cover in both sites. We carried out a 10-year analysis (1994–2004) of rain, temperature, wind speed, relative humidity, and potential evaporation at the 2 sites. Total summer rainstorm duration in JER was shorter (43 hr in comparison to 46 hr in SEV), and the temperature in JER was higher (by ~3 °C), relative humidity lower (by 3–6%) and vapor pressure deficit higher (by 0.5–0.6 kPa) in comparison to SEV. In addition, during the summer growing period, hourly wind speed was by 18.0% higher and monthly pan A evaporation was by 9.1% higher in JER, pointing out that time duration during which the soil remains wet during the summer is apparently much shorter in JER. Our results indicate that surface wetness in JER following rainstorms is apparently below the necessary threshold needed for successful grass establishment in JER. This in turn has broad consequences on the ecosystem hydrology, structure, and function.
      PubDate: 2017-03-27T19:40:46.136977-05:
      DOI: 10.1002/eco.1849
       
  • Grazing increases evapotranspiration without the cost of lowering soil
           water storages in arid ecosystems
    • Authors: Daniel A. Pereyra; Sandra J. Bucci, Nadia S. Arias, Nicolás Ciano, Piedad M. Cristiano, Guillermo Goldstein, Fabián G. Scholz
      Abstract: Grazing is the predominant land use practice in arid environments; however, there are relatively few studies of grazing effects on ecosystem functioning. We assessed the impact of grazing on soil moisture, evapotranspiration (ET), canopy conductance (Gc), and root water uptake in the Patagonian steppe. Studies were done in 3 sites along a gradient of grazing intensity. High grazing intensity increased the soil water storage by 24% and decreased the amount of water extracted from deep layers compared to the low grazing intensity. Grazing affected ET and its partitioning into transpiration (T) and evaporation. High shrub cover and Gc increased ET and T or ET partitioning in the heavily grazed site. Annual ET increased from 78% to 92% of the annual precipitation from the lowest to the highest grazing intensity, respectively. Total T was 21% higher in the highest intensity site compared to the lowest intensity site. Changes in Gc suggest that grazing modified the canopy architecture, and thus the response of vegetation to environmental factors. At the beginning of the growing season when moisture was high, Gc exhibited the highest value in the heavily grazed site, but a strong regulation of water losses was observed under drier conditions. This study emphasizes the need to assess simultaneously multiple factors for understanding regulatory mechanisms of grazing effects on hydrological processes. From a sustainable management point of view, we suggest that increasing the number of water sources, and thus spreading the sheep in a paddock, can enhance the stocking rate while maintaining soil water storage.
      PubDate: 2017-03-27T19:40:31.478705-05:
      DOI: 10.1002/eco.1850
       
  • Flow alteration signatures of diversion hydropower: An analysis of 32
           rivers in southwestern China
    • Authors: Kelly M. Kibler; Mohammadhossein Alipour
      Abstract: Hydrologic changes caused by diversion hydropower are poorly described. Herein, we evaluate hydrologic alteration in 32 ungauged rivers developed for diversion hydropower. We simulated long-term unregulated discharge records before perturbing flows with the hydropower diversion and comparing periods with and without diversion. We detected statistically significant changes to flow regime metrics across all rivers. Magnitudes across a range of flows consistently decreased following diversion, flow variability decreased substantially, and transitions between flows of different magnitudes became more abrupt. Magnitudes of 7-day minimum flows were lower by a mean of 41 ± 23% (p 
      PubDate: 2017-03-27T19:36:05.069343-05:
      DOI: 10.1002/eco.1846
       
  • How the evaporation of dry dune grasslands evolves during the concerted
           succession of soil and vegetation
    • Authors: B.R. Voortman; Y. Fujita, R.P. Bartholomeus, C.J.S. Aggenbach, J.P.M. Witte
      Abstract: Sustainable water and vegetation management of coastal dunes requires fundamental knowledge of how interactions between soil, water, and vegetation evolve during succession. Therefore, we quantified the effect of succession on evaporation in dry dune grasslands of the Netherlands. On the basis of vegetation and soil records, we simulated the evaporation rate of vegetation plots that differed in successional stage, slope angle and slope orientation. Starting from bare sand, average yearly evaporation increased with 94 mm in a period of 52 to 76 years of soil and vegetation succession. The increase in evaporation was for the greater part caused by soil development (an increase of the water holding capacity) and the lesser part by an increase in vascular plant cover. In an early successional stage, ground layer evaporation could be both higher and lower compared to bare soil evaporation, depending on the moss species. At a later successional stage, moss species primarily decreased ground layer evaporation and facilitated vascular plants. Despite clear differences in slope angle and slope orientation, the simulated actual evaporation rate was not significantly correlated to the incoming solar radiation because the vascular plant cover and soil water holding capacity decreased with incoming solar radiation. These results show that biotic processes can eliminate the effects of micrometeorological differences on evaporation. On the basis of our findings, we hypothesize that vegetation shifts towards more moss- and lichen-dominated vegetation could mitigate the adverse effects of climate change (e.g., drier summers) on water resources.
      PubDate: 2017-03-27T19:35:44.638787-05:
      DOI: 10.1002/eco.1848
       
  • Source water contributions and hydrologic responses to simulated emerald
           ash borer infestations in depressional black ash wetlands
    • Authors: Matthew J. Van Grinsven; Joseph P. Shannon, Joshua C. Davis, Nicholas W. Bolton, Joseph W. Wagenbrenner, Randall K. Kolka, Thomas Grant Pypker
      Abstract: Forested wetlands dominated by black ash (Fraxinus nigra) are currently threatened by the rapid expansion of the exotic emerald ash borer (EAB) (Agrilus planipennis, Coleoptera: Buprestidae) in North America, and very little is known about the hydrology and ecology of black ash wetlands. The ecohydrological response of forested wetlands following a canopy disturbance has the potential to affect critical ecosystem services, and the degree of this effect may largely depend on the wetland's hydrogeological setting. The main objectives of this study were to characterize the hydrologic connectivity of un-infested black ash wetlands and evaluate the water table response to a simulated EAB disturbance. We hypothesized that black ash wetlands in northern Michigan were 1) seasonally connected to, and derived the majority of their water from groundwater, and 2) wetland water tables would be elevated following a simulated EAB disturbance due to decreased transpiration with the loss of black ash. The results indicate that the black ash wetland sites received most of their water from groundwater discharge. Significantly smaller site transpiration fluxes and significantly slower rates of drawdown were detected during the growing season in the girdled and ash-cut treatment sites, and these responses collectively produced significantly elevated wetland water tables when compared to control sites in the latter portions of the growing season. However, the wetlands’ strong connection with groundwater sources likely buffered the magnitude of hydrological responses associated with the loss of black ash from the landscape.
      PubDate: 2017-03-27T17:44:12.804969-05:
      DOI: 10.1002/eco.1862
       
  • Hydraulic complexity at a large river confluence in the Amazon Basin
    • Authors: C. Gualtieri; M. Ianniruberto, N. Filizola, R. Ventura Santos, T. Endreny
      Abstract: Confluences are a classic feature in riverine networks with important ecological and morphological functions. A method to characterize the hydraulic complexity of a river based on velocity gradients was applied, for high and low flow conditions, to the Negro and Solimões Rivers confluence in the Amazon Basin. The applied metrics M1 and M2 approximate the drag forces imposed on aquatic organisms moving between two locations, and may identify potential habitat zones and edges. Metric M2 corresponded best with the hydraulic and morphological patterns in the confluence hydrodynamic zone, with the largest M2 values in the entrance of the confluence, centered at the mixing interface, and M2 values generally decaying laterally toward the banks and longitudinally with downstream distance. Seasonal decreases in discharge magnitude in the Amazon, and decreases in discharge between other river basins analyzed in this study, led to increases in hydraulic complexity metric M2. The hydraulic complexity metrics can characterize some aspects of habitat heterogeneity and contribute to an explanation for observations of increased species richness at Amazon basin confluences, and the larger ecological patterns of diversity increasing at nodes in riverine networks.
      PubDate: 2017-03-25T08:30:39.769567-05:
      DOI: 10.1002/eco.1863
       
  • Impact of Hydropeaking on Downstream Fish Habitat at the Goesan Dam in
           Korea
    • Authors: Sung-Uk Choi; Seung Ki Kim, Byungwoong Choi, Yeonjoo Kim
      Abstract: The impact of hydropeaking on downstream fish habitat was investigated. The study area is a 2.3 km long reach of the Dal River, located downstream from the Goesan Dam, Korea. Such short-term effects of hydropeaking as flow unsteadiness, down-ramping rate, transport of benthic macro-invertebrate, and changes in composite habitat suitability (CSI) and weighted usable area (WUA) were examined. To assess the change in CSI and WUA, physical habitat simulations were carried out. The 2D unsteady flow model and the habitat suitability index model were used for hydraulic and habitat simulations, respectively. Zacco platypus was selected as a target species of the study area. Hydraulic simulations showed that flow depth changes rapidly with time at the rising and falling stages of discharge due to hydropeaking and this impact propagates with time. The down-ramping rate was found to decrease gradually in the downstream direction, implying that the fish can be stranded in the 1.5 km upstream reach. In addition, simulation results indicate that the transport of macro-invertebrate may occur in the riffle, and the hydropeaking flows increase slightly the area of possible transport of macro-invertebrate compared with the normal flow. However, catastrophic drift will not occur due to hydropeaking flows. The results of physical habitat simulations revealed that the hydropeaking flows decrease the CSI although the river morphology affects the CSI to some extent. Regarding the WUA, the overall habitat quality in the entire study reach was found to decrease due to hydropeaking.
      PubDate: 2017-03-25T04:40:28.481585-05:
      DOI: 10.1002/eco.1861
       
  • Hydro-Climatic and Ecohydrological Resistance/Resilience Conditions Across
           Tropical Biomes of Costa Rica
    • Authors: Germain Esquivel-Hernández; Ricardo Sánchez-Murillo, Christian Birkel, Stephen P. Good, Jan Boll
      Abstract: Water resources management in the tropics is challenged by climate variability and unregulated land use change and their impacts on the complex interactions between vegetation, soil, and atmosphere. This study focuses on the analysis of hydro-climatic and ecohydrological conditions across six major biomes in Costa Rica. Using the Budyko and the Tomer-Schilling frameworks, 31 reanalysis data points located across the Caribbean and Pacific domains were classified according to their ecohydrological resistance and resilience between 1989 and 2005. Observed data were used to evaluate the reanalysis products. Resistance was defined as the standard deviation in the water excess (Q/P), while resilience was defined as the standard deviation of the energy (AET/ PET) to the water excess. A strong orographic separation was obtained between the water-limited Pacific slope and the energy-limited Caribbean slope. The Caribbean slope is characterized by low resistance and high resilience to changes in the hydro-climatic conditions, with small relative changes in water excess (-18% to 2.0%), whereas the Northern Pacific slope has high resistance and low resilience and exhibited strong changes in water excess (-34% to 0%). Some regions of the Northern Pacific region covered by lower and pre-montane forests have recently suffered significant increments in the dryness index (PET/P). This study demonstrates the need for national-regional strategies to effectively optimize water use efficiency and water storage and to include a climate vulnerability component in future water management plans.
      PubDate: 2017-03-22T21:20:49.90348-05:0
      DOI: 10.1002/eco.1860
       
  • The effects of catchment and riparian forest quality on stream
           environmental conditions across a tropical rainforest and oil palm
           landscape in Malaysian Borneo
    • Authors: Sarah H. Luke; Holly Barclay, Kawi Bidin, Vun Khen Chey, Robert M. Ewers, William A. Foster, Anand Nainar, Marion Pfeifer, Glen Reynolds, Edgar C. Turner, Rory P. D. Walsh, David C. Aldridge
      Abstract: Freshwaters provide valuable habitat and important ecosystem services but are threatened worldwide by habitat loss and degradation. In Southeast Asia, rainforest streams are particularly threatened by logging and conversion to oil palm, but we lack information on the impacts of this on freshwater environmental conditions, and the relative importance of catchment versus riparian-scale disturbance. We studied 16 streams in Sabah, Borneo, including old-growth forest, logged forest, and oil palm sites. We assessed forest quality in riparian zones and across the whole catchment and compared it with stream environmental conditions including water quality, structural complexity, and organic inputs. We found that streams with the highest riparian forest quality were nearly 4 °C cooler, over 20 cm deeper, had over 40% less sand, greater canopy cover, more stored leaf litter, and wider channels than oil palm streams with the lowest riparian forest quality. Other variables were significantly related to catchment-scale forest quality, with streams in the highest quality forest catchments having 40% more bedrock and 20 times more dead wood, along with higher phosphorus, and lower nitrate-N levels compared to streams with the lowest catchment-scale forest quality. Although riparian buffer strips went some way to protecting waterways, they did not maintain fully forest-like stream conditions. In addition, logged forest streams still showed signs of disturbance 10–15 years after selective logging. Our results suggest that maintenance and restoration of buffer strips can help to protect healthy freshwater ecosystems but logging practices and catchment-scale forest management also need to be considered.
      PubDate: 2017-03-21T03:31:04.367892-05:
      DOI: 10.1002/eco.1827
       
  • Topography may mitigate drought effects on vegetation along a hillslope
           gradient
    • Authors: Sandra Hawthorne; Chelcy Ford Miniat
      Abstract: Topography may mitigate drought effects on vegetation along a hillslope gradient through redistribution of soil moisture. We examined the interaction of topography, climate, soil moisture, and transpiration in a low-elevation, mixed-hardwood forest in the southern Appalachian Mountains. The effects of meteorological variation (wet and dry years) and topographic position (upslope and cove) were tested on daily soil moisture amplitude and recession and plot and species-specific transpiration. Trees in the cove plot were 17% taller and had 45% greater sapwood area than those in the upslope plot. Lower rates of soil moisture recession following rainfall events were observed at the cove plot compared to the upper plot. Greater daily soil moisture amplitude and plot transpiration, even in dry years, suggest that lower slope positions may have been buffered against moderate drought. We also observed similar transpiration in Quercus spp., Carya spp., and Liriodendron tulipifera in the cove plot between dry and wet years. Plot transpiration was reduced by 51% in the dry year in the upslope plot only, and transpiration by individual species in the plot reflected this pattern, suggesting water stress in dry years may be exacerbated by topography. With drought predicted to increase for these systems, the different drought responses of species, in addition to topographic effects, may lead to complex shifts in species composition.
      PubDate: 2017-03-16T00:15:59.624997-05:
      DOI: 10.1002/eco.1825
       
  • Knowing About Language: Linguistics and the Secondary English Classroom
    • Authors: Urszula Clark
      PubDate: 2017-03-15T04:40:22.992564-05:
      DOI: 10.1111/eie.12128
       
  • Ecohydrological controls on plant diversity in tropical South America
    • Authors: Sara Bonetti; Xue Feng, Amilcare Porporato
      Abstract: Plant species distribution is dominated by abundance and fluctuations of the available resources. Although diversity patterns along rainfall, latitudinal, and altitudinal gradients have been thoroughly examined, the role of hydrological processes insustaining the resource availability critical to species richness is still poorly understood. Adopting soil moisture as a main limiting factor driving plant diversity in the tropics besides elevation, we propose a minimalist species richness model based on stochastic soil water balance and information theory. The present work provides a novel approach to plant diversity modeling through a quantitative representation of the soil water balance, demonstrating the role of different modes of soil moisture temporal variability in the creation of ecohydrological niches. Using a single calibration parameter, the model captures the observed biodiversity patterns in tropical South America, effectively synthesizing the impacts of energy and water balances on species richness. We show that soil water abundance and variability are the strongest predictors of plant diversity in tropical South America besides elevation, with latitude and seasonal variation in potential evapotranspiration having a secondary effect. Excluding soil moisture abundance, seasonal and intra-seasonal variability reduces model accuracy by 50, 48, and 64%, respectively. The importance of atmospheric humidity as an additional plant water resource creating niches for canopy species is also highlighted. Our results suggest that accountingnot only for water abundance but also its variability is key to predicting biodiversity trends under future rainfall regimes.
      PubDate: 2017-03-14T22:50:24.733019-05:
      DOI: 10.1002/eco.1853
       
  • Assessing the hydroxyl radical and volatilization roles in aquatic fate
           estimations of sulfur heterocycles: Dibenzothiophene derivatives
    • Authors: Parichehr Saranjampour; Kevin L. Armbrust, Brian D. Marx
      Abstract: Polycyclic aromatic sulfur heterocycles (PASHs) and their alkyl derivatives can be released into aquatic systems via crude oil spills or runoff from petroleum-treated areas, such as asphalt. Dibenzothiophene (DBT) and its derivatives (C1-DBT, C2-DBT, and C4-DBT) were chosen as model compounds to investigate the relative impact of volatilization and hydroxyl radical degradation on estimates of their overall dissipation after entry into aquatic ecosystems as a function of depth using the exposure analysis modeling system (EXAMS). The hydroxyl radical rate constant (K · OH) and Henry's law constant of PASHs were determined in distilled water. The analogue C1-DBT reacted fastest with · OH relative to other PASHs. The C2-DBT and C4-DBT analogues had higher Henry's law constants compared with other derivatives. Steric hindrance by alkyl substituents on the sulfur moiety most strongly impacted measured rate and Henry's law constants between DBT and individual alkyl derivatives. These steric effects do not appear to be considered in the physical property estimation software EPI Suite. Simulated dissipation of PASHs using EXAMS suggests that volatilization is a dominant fate pathway for the higher molecular weight and less polar C2-DBT and C4-DBT at all depths and DBT and C1-DBT at 0.1-m. However, model scenarios suggest that hydroxyl radical degradation may significantly contribute to the degradation of more polar DBT and C1-DBT at 1-m and 2-m depths. Environ Toxicol Chem 2017;9999:1–7. © 2017 SETAC
      PubDate: 2017-03-07T09:15:33.264387-05:
      DOI: 10.1002/etc.3745
       
  • An ecohydrological framework to explain shifts in vegetation organization
           across climatological gradients
    • Authors: Salvatore Manfreda; Kelly K. Caylor, Stephen P. Good
      Abstract: Spatial patterns found in vegetated ecosystems exhibit different degrees of organization in stand density that can be interpreted as an indicator of ecosystem health. In semiarid environments, it is possible to observe transitions from over-dispersed individuals (e.g., an ordered lattice) to under-dispersed individuals (e.g., clumped points). These configurations correspond to different strategies of adaptation or optimization, whose understanding may help to predict some of the consequences of environmental changes for both ecosystem services and water resources. For this reason, we have developed a theoretical framework that characterizes the dispersion of individuals through a generalized double Poisson distribution and estimates the landscape-wide statistics using a soil moisture model accounting for tree canopies and root systems overlapping. Considering both the shading effect (light interception) of the canopies and the partitioning of water fluxes due to the presence of multiple individual root systems in one point, the optimum spacing between individuals at a given stand density is determined. This framework allows identifying the climatic boundaries for different landscape patterns in terms of optimal water use and stress. This simple scheme explains well the observed patterns of vegetation in arid and semiarid ecosystems.
      PubDate: 2017-03-07T05:31:01.313597-05:
      DOI: 10.1002/eco.1809
       
  • Evaluating canopy transpiration and water use of two typical planted tree
           species in the dryland Loess Plateau of China
    • Authors: Handan Zhang; Wei Wei, Liding Chen, Lei Yang
      Abstract: Large-scale vegetation restoration has been conducted in China's Loess Plateau over the past several decades to control soil and water loss. However, these efforts have not followed any specific guidelines to select plant species that balance the twin goals of vegetation restoration and water demand. In the present study, we measured canopy transpiration characteristics of oriental arborvitae (Platycladus orientalis) and Chinese pine (Pinus tabulaeformis), two species that are commonly planted in restoration efforts, and recorded water input and output for these two species during the growing season. P. tabulaeformis had a higher tolerance than P. orientalis to warmer and drier environments and used water over a wider time span. Canopy transpiration significantly increased when rainfall exceeded 15 mm and was negatively correlated with net change of soil water content. Meanwhile, rainless intervals also affected canopy transpiration recovery. Canopy transpiration of P. tabulaeformis was 25.4% higher than that of P. orientalis. Soil water content under P. orientalis declined by 28.4% after the growing season, while it slightly increased under P. tabulaeformis (0.7%). Our results suggested that although P. tabulaeformis plantation had higher canopy transpiration, this water use did not drastically reduce soil water content, mainly due to the lower evaporation caused by the dense canopy cover. However, the low soil water content also implied that a better management, such as a mixed plantation of these two species and other supplemental water-conservation techniques, should be considered to better use water in this semiarid region.
      PubDate: 2017-03-07T05:30:52.887107-05:
      DOI: 10.1002/eco.1830
       
  • Combined environmental risk assessment for the antiviral pharmaceuticals
           ganciclovir and valganciclovir in Europe
    • Authors: Jürg Oliver Straub
      Abstract: Potential environmental risks of the old antiviral pharmaceuticals ganciclovir (GCV) and valganciclovir (VGCV) were reassessed based on new environmental fate and chronic ecotoxicity tests and on actual use data for Europe. Valganciclovir is hydrolyzed to GCV by intestinal and hepatic esterases, and hence the new environmental tests only refer to GCV. A sorption study showed that GCV will not sorb significantly, excluding the soil as a relevant environmental compartment. Despite earlier data suggesting nondegradability, a new water/sediment fate test showed GCV to be primarily and ultimately degraded and to be nonpersistent. The chronic ecotoxicity tests with algae and daphnids resulted in no inhibition at the highest tested concentrations, whereas a fish partial life cycle test, selected in view of mammalian mutagenicity and reprotoxicity data, showed effects on growth of the young fish, but not on gametogenesis, fertilization, embryogenesis, or teratogenicity. Predicted environmental concentrations were derived based on actual per capita use data for European countries for 2004 to 2014, and the highest was selected for the risk assessment. A comparison of predicted environmental concentrations with predicted no-effect concentrations shows no significant risk for wastewater treatment, surface waters, groundwater, or sediment. In addition, potential risks to (semi)aquatic top predators or to human consumers of water and fish are exceedingly low. Environ Toxicol Chem 2016;9999:1–12. © 2017 The Author. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC
      PubDate: 2017-03-06T15:00:24.455479-05:
      DOI: 10.1002/etc.3758
       
  • The effects of epoxiconazole and α-cypermethrin on Daphnia magna growth,
           reproduction, and offspring size
    • Authors: Michele Gottardi; Michala Rosa Birch, Kristoffer Dalhoff, Nina Cedergreen
      Abstract: Two of the main classes of pesticides commonly used in agriculture are azole fungicides and pyrethroid insecticides. Because azoles have been shown to synergize the effect of pyrethroids, the effect of their mixture is of concern. The aim of the present study was to investigate the effect of sublethal concentrations of epoxiconazole and α-cypermethrin and their mixture on growth, reproduction, and in vivo cytochrome P450 activity of the aquatic crustacean Daphnia magna over 42 d. Continuous exposure to nonlethal concentrations of α-cypermethrin at 20 ng/L negatively affected adult growth and number and size of neonates within the first 14 d of exposure. Exposure to epoxiconazole at 25 μg/L increased protein content of adults within 1 to 3 d after initiating exposure and increased cumulative number of offspring at exposure times >31 d. Epoxiconazole enhanced the negative effect of α-cypermethrin up to 3-fold leading to decreased growth, cytochrome P450 activity, and reproduction of D. magna within the first 14 d of exposure. After 14 d, the synergistic interactions disappeared. The reported effects, although lacking direct negative consequence in the long term, might have cumulative toxicity with other stressors such as food scarcity, predation, and pathogens, posing an additional hazard for the organisms at the beginning of their life cycle. Environ Toxicol Chem 2017;9999:1–12. © 2017 SETAC
      PubDate: 2017-03-06T14:35:27.798549-05:
      DOI: 10.1002/etc.3752
       
  • Bioaccumulation, stress, and swimming impairment in Daphnia magna exposed
           to multiwalled carbon nanotubes, graphene, and graphene oxide
    • Authors: Amanda M. Cano; Jonathan D. Maul, Mohammad Saed, Smit A. Shah, Micah J. Green, Jaclyn E. Cañas-Carrell
      Abstract: The use of carbon-based nanomaterials (CNMs) such as multiwalled carbon nanotubes (MWCNTs), graphene, and graphene oxide (GO) is increasing across many applications because of their unique and versatile properties. These CNMs may enter the aquatic environment through many pathways, creating the potential for organism exposure. The present study addresses the bioaccumulation and toxicity seen in Daphnia magna exposed to CNMs dispersed in sodium dodecyl benzene sulfonate (SDBS). In study I, D. magna were exposed to varying outer diameters of MWCNTs for 24 h in moderately hard or hard freshwater. Bioaccumulation of MWCNT was found in all treatments, with the highest concentrations (0.53 ± 0.27 μg/g) in D. magna exposed in hard freshwater (p 
      PubDate: 2017-03-06T14:30:24.202285-05:
      DOI: 10.1002/etc.3754
       
  • Estimates of evapotranspiration from contrasting Wisconsin peatlands based
           on diel water table oscillations
    • Authors: C.J. Watras; K.A. Morrison, J.L. Rubsam, I. Buffam
      Abstract: Evapotranspiration rates (ET) from contrasting Wisconsin bogs (one forested bog, one open bog) were compared over 4 years by analyzing diel oscillations of their water tables. Daily rates of ET from peatlands were also compared to rates of evaporation (E) from encircled bog ponds. We hypothesized that ET would be higher in the forested bog due to the greater leaf area index of forest canopy relative to moss and ericaceous shrubs. We also hypothesized that ET in peatlands would exceed the physical process of E from encircled ponds. Field data supported the first hypothesis, but the second only proved true for the forested peatland. Daily estimates of peatland ET varied widely, ranging from ~1 to >10 mm/d; but average ET was higher in the forested peatland (4.04 vs. 3.09 mm/d; p 
      PubDate: 2017-03-02T05:10:52.900736-05:
      DOI: 10.1002/eco.1834
       
  • Flood regime typology for floodplain ecosystem management as applied to
           the unregulated Cosumnes River of California, United States
    • Authors: Alison A. Whipple; Joshua H. Viers, Helen E. Dahlke
      Abstract: Floods, with their inherent spatiotemporal variability, drive floodplain physical and ecological processes. This research identifies a flood regime typology and approach for flood regime characterization, using unsupervised cluster analysis of flood events defined by ecologically meaningful metrics, including magnitude, timing, duration, and rate of change as applied to the unregulated lowland alluvial Cosumnes River of California, United States. Flood events, isolated from the 107-year daily flow record, account for approximately two-thirds of the annual flow volume. Our analysis suggests six flood types best capture the range of flood event variability. Two types are distinguished primarily by high peak flows, another by later season timing and long duration, two by small magnitudes separated by timing, and the last by later peak flow within the flood event. The flood regime was also evaluated through inter- and intra-annual frequency of the identified flood types, their relationship to water year conditions, and their long-term trends. This revealed, for example, year-to-year variability in flood types, associations between wet years and high peak magnitude types and between dry years and the low magnitude, late season flood type, and increasing and decreasing contribution to total annual flow in the highest two peak magnitude classes, respectively. This research focuses needed attention on floodplains, flood hydrology, ecological implications, and the utility of extending flow regime classification typically used for environmental flow targets. The approach is broadly applicable and extensible to other systems, where findings can be used to understand physical processes, assess change, and improve management strategies.
      PubDate: 2017-03-02T05:10:43.053559-05:
      DOI: 10.1002/eco.1817
       
  • The two water worlds hypothesis: Addressing multiple working hypotheses
           and proposing a way forward
    • Authors: Z. Carter Berry; Jaivime Evaristo, Georgianne Moore, María Poca, Kathy Steppe, Lucile Verrot, Heidi Asbjornsen, Laura S. Borma, Mario Bretfeld, Pedro Hervé-Fernández, Mark Seyfried, Luitgard Schwendenmann, Katherine Sinacore, Lien De Wispelaere, Jeffrey McDonnell
      Abstract: Recent studies using water isotopes have shown that trees and streams appear to return distinct water pools to the hydrosphere. Cryogenically extracted plant and soil water isotopic signatures diverge from the meteoric water lines, suggesting that plants would preferentially use bound soil water, while mobile soil water that infiltrates the soil recharges groundwater and feeds streamflow all plots on meteoric water lines. These findings have been described under the “two water worlds” (TWW) hypothesis. In spite of growing evidence for the TWW hypothesis, several questions remain unsolved within the scope of this framework. Here, we address the TWW as a null hypothesis and further assess the following: (a) the theoretical biophysical feasibility for two distinct water pools to exist, (b) plant and soil processes that could explain the different isotopic composition between the two water pools, and (c) methodological issues that could explain the divergent isotopic signatures. Moreover, we propose a way forward under the framework of the TWW hypothesis, proposing alternative perspectives and explanations, experiments to further test them, and methodological advances that could help illuminate this quest. We further highlight the need to improve our sampling resolution of plants and soils across time and space. We ultimately propose a set of key priorities for future research to improve our understanding of the ecohydrological processes controlling water flows through the soil–plant-atmosphere continuum.
      PubDate: 2017-03-02T05:10:29.672825-05:
      DOI: 10.1002/eco.1843
       
  • A re-evaluation of PETROTOX for predicting acute and chronic toxicity of
           petroleum substances
    • Authors: Aaron D. Redman; Thomas F. Parkerton, Miriam Leon Paumen, Josh D. Butler, Daniel J. Letinski, Klass den Haan
      Abstract: The PETROTOX model was developed to perform aquatic hazard assessment of petroleum substances based on substance composition. The model relies on the hydrocarbon block method, which is widely used for conducting petroleum substance risk assessments providing further justification for evaluating model performance. Previous work described this model and provided a preliminary calibration and validation using acute toxicity data for limited petroleum substance. The objective of the present study was to re-evaluate PETROTOX using expanded data covering both acute and chronic toxicity endpoints on invertebrates, algae, and fish for a wider range of petroleum substances. The results indicated that recalibration of 2 model parameters was required, namely, the algal critical target lipid body burden and the log octanol–water partition coefficient (KOW) limit, used to account for reduced bioavailability of hydrophobic constituents. Acute predictions from the updated model were compared with observed toxicity data and found to generally be within a factor of 3 for algae and invertebrates but overestimated fish toxicity. Chronic predictions were generally within a factor of 5 of empirical data. Furthermore, PETROTOX predicted acute and chronic hazard classifications that were consistent or conservative in 93 and 84% of comparisons, respectively. The PETROTOX model is considered suitable for the purpose of characterizing petroleum substance hazard in substance classification and risk assessments. Environ Toxicol Chem 2016;9999:1–8. © 2017 SETAC
      PubDate: 2017-02-28T10:55:24.892133-05:
      DOI: 10.1002/etc.3744
       
  • Riparian plant species preferences indicate diversification of site
           conditions after river restoration
    • Authors: Patrick Modrak; Stefan Brunzel, Armin W. Lorenz
      Abstract: Numerous river restoration projects have been undertaken to improve the hydromorphology of rivers and their floodplains. Subsequent ecological monitoring is usually restricted to instream quality assessment while riparian areas and floodplains are rarely assessed. A good indicator for riparian assessment could be vegetation as its diversity is dependent on functioning hydromorphological processes.We used a comparative survey to test the effect of newly created river morphological features on riparian plant composition at restored reaches relative to non-restored reaches. We investigated 43 larger river restoration projects in Western Germany, realized between 1987 and 2008. The vegetation surveys were conducted between 2005 and 2013.We hypothesized that a) morphological river restoration leads to the diversification of riparian vegetation, higher reach-scale habitat heterogeneity and optimized habitats. These changes will b) be reflected by ecological preferences indicating hydromorphological functioning.We detected significantly higher species diversity in restored reaches. New habitats and hydrological interactions in the active channel and with the floodplains were fundamental, with the latter indicated by species preferences. In restored reaches we observed higher percentages of plants indicating regular flooding, significantly higher mean moisture tolerances and an extended range of moisture preferences.ConclusionsMorphological river restoration can diversify and fundamentally influence riparian vegetation. Ecologically meaningful projects should address the rehabilitation of abiotic processes, focusing on a functioning flooding regime and near-natural riparian habitats. Riparian vegetation will reflect the improvements and consequently could be used as an indicator for restoration efforts. Thus, riparian vegetation assessment is worthy of consideration through legal obligations.
      PubDate: 2017-02-27T22:00:21.472821-05:
      DOI: 10.1002/eco.1852
       
  • Effects of metals on enantioselective toxicity and biotransformation of
           cis-bifenthrin in zebrafish
    • Authors: Ye Yang; Dapeng Ji, Xin Huang, Jianyun Zhang, Jing Liu
      Abstract: Co-occurrence of pyrethroids and metals in watersheds previously has been reported to pose great risk to aquatic species. Pyrethroids are a class of chiral insecticides that have been shown to have enantioselective toxicity and biotransformation. However, the influence of metals on enantioselectivity of pyrethroids has not yet been evaluated. In the present study, the effects of cadmium (Cd), copper (Cu), and lead (Pb) on the enantioselective toxicity and metabolism of cis-bifenthrin (cis-BF) were investigated in zebrafish at environmentally relevant concentrations. The addition of Cd, Cu, or Pb significantly increased the mortality of zebrafish in racemate and R-enantiomer of cis-BF–treated groups. In rac-cis-BF– or 1R-cis-BF–treated groups, the addition of Cd, Cu, or Pb caused a decrease in enantiomeric fraction (EF) and an increased ratio of R-enantiomer residues in zebrafish. In 1S-cis-BF–treated groups, coexposure to Cd led to a lower EF and decreased residue levels of S-enantiomer. In addition, coexposure to the 3 metals resulted in different biodegradation characteristics of each enantiomer accompanied with differential changes in the expression of cytochrome P450 (CYP)1, CYP2, and CYP3 genes, which might be responsible for the enantioselective biodegradation of cis-BF in zebrafish. These results suggest that the influence of coexistent metals should be considered in the ecological risk assessment of chiral pyrethroids in aquatic environments. Environ Toxicol Chem 2017;9999:1–8. © 2017 SETAC
      PubDate: 2017-02-23T14:45:35.724356-05:
      DOI: 10.1002/etc.3747
       
  • Comparison of four methods for bioavailability-based risk assessment of
           mixtures of Cu, Zn, and Ni in freshwater
    • Authors: Tina Regenmortel; Charlotte Nys, Colin R. Janssen, Stephen Lofts, Karel A.C. Schamphelaere
      Abstract: Although chemical risk assessment is still mainly conducted on a substance-by-substance basis, organisms in the environment are typically exposed to mixtures of substances. Risk assessment procedures should therefore be adapted to fit these situations. Four mixture risk assessment methodologies were compared for risk estimations of mixtures of copper (Cu), zinc (Zn), and nickel (Ni). The results showed that use of the log-normal species sensitivity distribution (SSD) instead of the best-fit distribution and sampling species sensitivities independently for each metal instead of using interspecies correlations in metal sensitivity had little impact on risk estimates. Across 4 different monitoring datasets, between 0% and 52% of the target water samples were estimated to be at risk, but only between 0% and 15% of the target water samples were at risk because of the mixture of metals and not any single metal individually. When a natural baseline database was examined, it was estimated that 10% of the target water samples were at risk because of single metals or their mixtures; when the most conservative method was used (concentration addition [CA] applied directly to the SSD, i.e., CASSD). However, the issue of metal mixture risk at geochemical baseline concentrations became relatively small (2% of target water samples) when a theoretically more correct method was used (CA applied to individual dose response curves, i.e., CADRC). Finally, across the 4 monitoring datasets, the following order of conservatism for the 4 methods was shown (from most to least conservative, with ranges of median margin of safety [MoS] relative to CASSD): CASSD > CADRC (MoS = 1.17–1.25) > IADRC (independent action (IA) applied to individual dose-response curves; MoS = 1.38–1.60) > IASSD (MoS = 1.48–1.72). Therefore, it is suggested that these 4 methods can be used in a general tiered scheme for the risk assessment of metal mixtures in a regulatory context. In this scheme, the CASSD method could serve as a first (conservative) tier to identify situations with likely no potential risk at all, regardless of the method used (the sum toxic unit expressed relative to the 5% hazardous concentration [SumTUHC5]  0.05). The CADRC and IADRC methods could be used for site-specific assessment for situations that fall in between (SumTUHC5 > 1 and msPAFIA,SSD 
      PubDate: 2017-02-23T14:45:33.506051-05:
      DOI: 10.1002/etc.3746
       
  • Effects of cadmium, manganese, and lead on locomotor activity and neurexin
           2a expression in zebrafish
    • Authors: Hongwei Tu; Chengji Fan, Xiaohui Chen, Jiaxian Liu, Bin Wang, Zhibin Huang, Yiyue Zhang, Xiaojing Meng, Fei Zou
      Abstract: The synaptic adhesion protein Neurexin 2a (Nrxn2a) plays a key role in neuronal development and is associated with cognitive functioning and locomotor behavior. Although low-level metal exposure poses a potential risk to the human nervous system, especially during the developmental stages, little is known about the effects of metal exposures on nrxn2a expression during embryonic development. We therefore exposed wild-type zebrafish embryos/larvae to cadmium (CdCl2), manganese (MnCl2), and lead ([CH3COO]2Pb), to determine their effect on mortality, malformation, and hatching rate. Concentrations of these metals in zebrafish were detected by inductively coupled plasma mass spectrometry analysis. Locomotor activity of zebrafish larvae was analyzed using a video-track tracking system. Expression of nrxn2a was assessed by in situ hybridization and quantitative polymerase chain reaction. The results showed that mortality, malformation, and bioaccumulation increased as the exposure dosages and duration increased. Developmental exposure to these metals significantly reduced larval swim distance and velocity. The nrxn2aa and nrxn2ab genes were expressed in the central nervous system and downregulated by almost all of the 3 metals, especially Pb. These data demonstrate that exposure to metals downregulates nrxn2a in the zebrafish model system, and this is likely linked to concurrent developmental processes. Environ Toxicol Chem 2017;9999:1–8. © 2017 SETAC
      PubDate: 2017-02-23T14:45:29.421561-05:
      DOI: 10.1002/etc.3748
       
  • Species-specific and structure-dependent debromination of polybrominated
           diphenyl ether in fish by in vitro hepatic metabolism
    • Authors: Yuan-Lai Luo; Xiao-Jun Luo, Mei-Xia Ye, Yan-Hong Zeng, She-Jun Chen, Bi-Xian Mai
      Abstract: To explore the cause of species-specific differences and structure–activity relationships in the debromination of polybrominated diphenyl ethers (PBDEs) in fish, a series of in vitro measurements of hepatic metabolism of PBDE were made using crucian carp (Carassius carassius) and catfish (Silurus asotus) and the activity of deiodinase in liver microsomes was measured. Debromination was observed in the crucian carp but not in the catfish. No difference was found in total deiodinase activity despite the activity of type 1 deiodinase in crucian carp being twice that of catfish. It is difficult to determine whether the differences in deiodinase activity were responsible for the species-specific differences observed. In crucian carp, penta-brominated diphenyl ether congeners exhibited the highest debromination rates, and the transformation rate decreased with an increasing number of substituted bromines. Adjacent bromine substitution in the phenyl ring was a necessary, but insufficient, condition for debromination in crucian carp. Doubly flanked bromine was always preferentially removed, while single-flanked bromine, meta-substituted bromine, was debrominated the most, followed by para- and then ortho-bromine. No debromination was observed for single-flanked bromine when there was a symmetrical structure with (2, 4, 6) bromine substitutions in 1 phenyl ring, indicating that this structure can improve resistance to debromination metabolism. Environ Toxicol Chem 2017;9999:1–7. © 2017 SETAC
      PubDate: 2017-02-23T14:45:27.231397-05:
      DOI: 10.1002/etc.3749
       
  • Returning to normal? Assessing transcriptome recovery over time in male
           rainbow darter (Etheostoma caeruleum) liver in response to
           wastewater-treatment plant upgrades
    • Authors: Patricija Marjan; Christopher J. Martyniuk, Meghan L.M. Fuzzen, Deborah L. MacLatchy, Mark E. McMaster, Mark R. Servos
      Abstract: The present study measured hepatic transcriptome responses in male rainbow darter (Etheostoma caeruleum) exposed to 2 municipal wastewater-treatment plants (MWWTPs; Kitchener and Waterloo) over 4 fall seasons (2011–2014) in the Grand River (Ontario, Canada). The overall goal was to determine if upgrades at the Kitchener MWWTP (in 2012) resulted in transcriptome responses indicative of improved effluent quality. The number of differentially expressed probes in fish downstream of the Kitchener outfall (904–1223) remained comparable to that downstream of Waterloo (767–3867). Noteworthy was that year and the interaction of year and site explained variability in more than twice the number of transcripts than site alone, suggesting that year and the interaction of year and site had a greater effect on the transcriptome than site alone. Gene set enrichment analysis revealed a gradual reduction in the number of gene ontologies over time at exposure sites, which corresponded with lower contaminant load. Subnetwork enrichment analysis revealed that there were noticeable shifts in the cell pathways differently expressed in the liver preupgrade and postupgrade. The dominant pathways altered preupgrade were related to genetic modifications and cell division, whereas postupgrade they were associated with the immune system, reproduction, and biochemical responses. Molecular pathways were dynamic over time, and following the upgrades, there was little evidence that gene expression profiles in fish collected from high-impact sites postupgrade were more similar to those in fish collected from reference site. Environ Toxicol Chem 2017;9999:1–15. © 2017 SETAC
      PubDate: 2017-02-23T11:45:27.103137-05:
      DOI: 10.1002/etc.3741
       
  • A rapid electrochemical monitoring platform for sensitive determination of
           thiamethoxam based on β–cyclodextrin-graphene composite
    • Authors: XingChen Zhai; Hua Zhang, Min Zhang, Xin Yang, Cheng Gu, GuoPeng Zhou, HaiTian Zhao, ZhenYu Wang, AiJun Dong, Jing Wang
      Abstract: A rapid monitoring platform for sensitive voltammetric detection of thiamethoxam residues is reported in the present study. A β–cyclodextrin-reduced graphene oxide composite was used as a reinforcing material in electrochemical determination of thiamethoxam. Compared with bare glassy carbon electrodes, the reduction peak currents of thiamethoxam at reduced graphene oxide/glassy carbon electrode and β–cyclodextrin-reduced graphene oxide/glassy carbon electrode were increased by 70- and 124-fold, respectively. The experimental conditions influencing voltammetric determination of thiamethoxam, such as the amount of β–cyclodextrin-reduced graphene oxide, solution pH, temperature, and accumulation time, were optimized. The reduction mechanism and binding affinity of this material is also discussed. Under optimal conditions, the reduction peak currents increased linearly between 0.5 µM and 16 µM concentration of thiamethoxam. The limit of detection was 0.27 µM on the basis of a signal-to-noise ratio of 3. When the proposed method was applied to brown rice in a recovery test, the recoveries were between 92.20% and 113.75%. The results were in good concordance with the high-performance liquid chromatography method. The proposed method therefore provides a promising and effective platform for sensitive and rapid determination of thiamethoxam. Environ Toxicol Chem 2017;9999:1–7. © 2017 SETAC
      PubDate: 2017-02-23T11:45:23.499749-05:
      DOI: 10.1002/etc.3743
       
  • Comparison of the effect of ionic liquids containing hexafluorophosphate
           and trifluoroacetate anions on the inhibition of growth and oxidative
           stress in spring barley and common radish
    • Authors: Robert Biczak; Barbara Pawłowska, Joanna Feder-Kubis, Arkadiusz Telesiński
      Abstract: Ionic liquids are a group of chemical compounds with chemical properties that are of great interest to various fields of science and industry. However, commercial use of these substances raises concern because they may threaten the natural ecosystems. The present study used 2 types of (−)-menthol-containing imidazolium chiral ionic liquids: 1-[(1R,2S,5R)-(−)-menthoxymethyl]-3-methylimidazolium hexafluorophosphate [Im-Men][PF6] and 1-[(1R,2S,5R)-(−)-menthoxymethyl]-3-methylimidazolium trifluoroacetate [Im-Men][CF3CO2]. The effects of these compounds on growth and development of spring barley (Hordeum vulgare) and common radish (Raphanus sativus L. subvar. radicula Pers.) were investigated. The present study demonstrated that chiral ionic liquids produced a relatively high phytotoxicity, by shortening the plants’ lengths and roots, thus causing a decline in the experimental plants’ fresh weights. The investigated ionic liquids also led to a reduction in photosynthetic pigment levels, changes in hydrogen peroxide and malondialdehyde content, and changes in the activities of superoxide dismutase, catalase, and peroxidase in both plants. Changes in these enzymes were used to indicate oxidative stress levels in spring barley and common radish. It was demonstrated that imidazolium ionic liquid–induced phytotoxicity depended largely on the type of anion. The liquid [Im-Men][PF6] exhibited higher toxicity toward spring barley and common radish seedlings. Common radish was more resistant to chiral ionic liquids. Environ Toxicol Chem 2017;9999:1–11. © 2017 SETAC
      PubDate: 2017-02-23T11:40:37.054302-05:
      DOI: 10.1002/etc.3751
       
  • The characterization of dissolved organic matter extracted from different
           sources and their influence on cadmium uptake by Microcystis aeruginosa
    • Authors: Lixiao Ni; Lili Su, Shiyin Li, Peifang Wang, Dandan Li, Xiang Ye, Yi Li, Yong Li, Yiping Li, Chao Wang
      Abstract: The present study examines the uptake of the heavy metal cadmium (Cd) by Microcystis aeruginosa in the presence of dissolved organic matter (DOM) from different origins. The DOM used in the present study were extracted from soil, sediment taken from Meiliang Bay at Taihu Lake, and from M. aeruginosa cultured in the laboratory. The 3 different DOM samples were characterized using ultraviolet–visible absorption spectroscopy and Fourier transform infrared spectroscopy. The excitation-emission matrix (EEM) fluorescence spectroscopy was used to characterize the interactions of DOM with Cd2+. The results showed that all types of DOM extracted from the 3 sources in the present study exhibited aliphatic and aromatic characteristics and contained hydroxyls, carbonyls, phenols, carboxyls, carbohydrates, amines, and ethers. Humic acids and fulvic acids proved to be the major components of DOM. The sediment DOM had the highest degrees of aromatization and humification among the samples. The results also showed that sediment and soil DOM samples had lower molecular weights than M. aeruginosa DOM. The DOM could react with Cd2+ by complexing to alter Cd speciation. When exposed to Cd, EEM fluorescence intensities of all 3 DOM types had a significant decrease, and the intracellular Cd content improved with increasing Cd concentrations. The addition of DOM greatly enhanced Cd uptake by M. aeruginosa compared with the control group. Environ Toxicol Chem 2017;9999:1–8. © 2017 SETAC
      PubDate: 2017-02-23T11:40:30.725946-05:
      DOI: 10.1002/etc.3728
       
  • Integrative effects of zinc and temperature on germination in Dimorphandra
           wilsonii rizz.: Implications of climate changes
    • Authors: Elisa Monteze Bicalho; Marcelo Pedrosa Gomes, Ailton Gonçalves Rodrigues-Junior, Túlio Gabriel Soares Oliveira, Cintia Almeida Gonçalves, Marcia Bacelar Fonseca, Queila Souza Garcia
      Abstract: The integrative effects of zinc (Zn; 0 mg L−1, 75 mg L−1, 150 mg L−1, and 200 mg L−1) and temperature (25 °C, 30 °C, and 35 °C) on seed germination of the threatened Brazilian species Dimorphandra wilsonii were evaluated. Zinc effects on seed germination were only observed at 30 °C and 35 °C. By stimulating respiration rates, rising temperatures accentuate hydrogen peroxide (H2O2) formation in germinating seeds in the presence of Zn. Seed Zn tolerance was related to the activation of enzymatic antioxidants, and ascorbate peroxidase (APX) activity had a central role in H2O2 scavenging under the highest temperatures tested. Increased APX activity allowed successful germination, whereas decreasing APX activity was accompanied by decreasing germination rates in Zn-treated seeds at 35 °C. Within a scenario of future climate change, it will be extremely important to avoid increasing Zn concentrations in natural habitats that would threaten conservation efforts directed toward this endangered plant species. Environ Toxicol Chem 2017;9999:1–7. © 2017 SETACZinc and temperature modulate respiration activity and germination in Dimorphandra wilsonii seeds.
      PubDate: 2017-02-23T11:40:26.942278-05:
      DOI: 10.1002/etc.3729
       
  • The effect of hydrological and hydrochemical parameters on the
           microdistribution of aquatic fauna in drip water in the Velika Pasica
           Cave, Central Slovenia
    • Authors: Wei Liu; Cuiying Zhou, Julia Ellis Burnet, Anton Brancelj
      Abstract: Water quality and quantity significantly affects the aquatic fauna in the epikarst and conversely can also reflect the hydrological environment. Intensive, long-term studies on hydrological and hydrochemical parameters were monitored at 4 permanent dripping sites (VP1–VP4) in the Velika Pasica Cave (Slovenian) over a period from 2006 to 2013 concurrently with aquatic fauna sampling. Multivariate methods were applied to elucidate the relationship between the environmental conditions and the resident aquatic ecosystem. Seven major aquatic taxa were collected from the drips, with Copepoda being the dominant taxa; however, the spatial distribution and composition of these species varied distinctively at the 4 study sites; the drip water from different sites had distinct hydrological and hydrochemical characteristics. The most significant parameters influencing community composition were drip water discharge volume and NO3− ion content. The results indicate that hydrology and hydrochemistry significantly influence the microdistribution of aquatic fauna within the epikarstic aquifer.
      PubDate: 2017-02-23T05:40:45.068277-05:
      DOI: 10.1002/eco.1835
       
  • The long-term legacy of geomorphic and riparian vegetation feedbacks on
           the dammed Bill Williams River, Arizona, USA
    • Authors: Li Kui; John C. Stella, Patrick B. Shafroth, P. Kyle House, Andrew C. Wilcox
      Abstract: On alluvial rivers, fluvial landforms and riparian vegetation communities codevelop as a result of feedbacks between plants and abiotic processes. The influence of vegetation on river channel and floodplain geomorphology can be particularly strong on dammed rivers with altered hydrology and reduced flood disturbance. We used a 56-year series of aerial photos on the dammed Bill Williams River (Arizona, USA) to investigate how (a) different woody riparian vegetation types influence river channel planform and (b) how different fluvial landforms drive the composition of riparian plant communities over time. We mapped vegetation types and geomorphic surfaces and quantified how relations between fluvial and biotic processes covaried over time using linear mixed models. In the decades after the dam was built, woody plant cover within the river's bottomland nearly doubled, narrowing the active channel by 60% and transforming its planform from wide and braided to a single thread and more sinuous channel. Compared with native cottonwood–willow vegetation, nonnative tamarisk locally induced a twofold greater reduction in channel braiding. Vegetation expanded at different rates depending on the type of landform, with tamarisk cover on former high-flow channels increasing 17% faster than cottonwood–willow. Former low-flow channels with frequent inundation supported a greater increase in cottonwood–willow relative to tamarisk. These findings give insight into how feedbacks between abiotic and biotic processes in river channels accelerate and fortify changes triggered by dam construction, creating river systems increasingly distinct from predam ecological communities and landforms, and progressively more resistant to restoration of predam forms and processes.
      PubDate: 2017-02-23T05:40:33.628001-05:
      DOI: 10.1002/eco.1839
       
  • Evaluating the impacts of hydrologic and geomorphic alterations on
           floodplain connectivity
    • Authors: Mark C. Stone; Colin F. Byrne, Ryan R. Morrison
      Abstract: The dynamic interaction between a river and its floodplain is important for a variety of hydrologic, ecological, and geomorphic processes. However, water management activities have widely disrupted the natural flow regime and in many cases reduced floodplain connectivity. Recent environmental flow research has called for techniques that incorporate hydrogeomorphic processes, which are important for ecological and riverscape health. The objective of this study was to evaluate the impacts of hydrologic alterations on floodplain dynamics and connectivity. Changes in floodplain inundation dynamics and interface dynamics were investigated for 2 hydrologic scenarios on 2 distinct rivers—the Gila River and the Rio Grande, both in New Mexico, USA. The objective was achieved using a combination of 2-D hydrodynamic models and analysis techniques to evaluate large spatial and temporal datasets. The results improved understanding of inundation patterns and water flux between the channel and floodplain under baseline and altered hydrologic scenarios. Due to the distinct qualities of the study sites, unique insights were gleaned. In the Gila River, discernible changes in floodplain dynamics were observed in spite of the relatively minor alterations from the baseline hydrologic conditions. In contrast, the Rio Grande results revealed the importance of not only hydrologic alterations but also channel incision on reduced floodplain connectivity. The proposed techniques can be adapted to a wide range of river systems depending on the nature of hydrologic or geomorphic alterations under consideration. As a result, the degree of alteration of floodplain connectivity can be better understood, leading to improved river management.
      PubDate: 2017-02-22T07:10:40.213283-05:
      DOI: 10.1002/eco.1833
       
  • Evapotranspiration from a primary subtropical evergreen forest in
           Southwest China
    • Authors: Qing-Hai Song; Elisa Braeckevelt, Yi-Ping Zhang, Li-Qing Sha, Wen-Jun Zhou, Yun-Tong Liu, Chuan-Sheng Wu, Zhi-Yun Lu, Otto Klemm
      Abstract: Evapotranspiration (ET) was observed over a 5-year period at a primary subtropical evergreen forest in southwest China. The study used the eddy covariance method and quantified the precipitation, throughfall, stemflow, soil evaporation, and routine meteorological parameters to analyze the contributions of stand-level transpiration and canopy interception loss to the total ET. The annual ET ranged between 785 and 901 mm. The average ratios ET–potential evapotranspiration were 0.45 and 0.87 during the dry and wet seasons, respectively. The relative contributions of soil evaporation, stand-level transpiration, and canopy interception loss to ET were quantified in order to understand their roles in today's climate and in a potential future climate. Solar radiation was a driver for ET, although the occurrence of drought limited the tree transpiration and thus ET. Specifically, deep soil moisture was an important driver of ET during the dry season. During the wet season, the vapor pressure deficit became one of the main drivers. Although the current study did not collect specific data for the effect of fog on ET, fog likely plays an important role in the ecohydrologic system and deserves further investigation. Although the hydrological system is currently stable, it is anticipated that the groundwater recharge from the ecosystem may be largely reduced in the future, likely through climate change and an associated positive temperature–ET feedback loop.
      PubDate: 2017-02-22T07:05:38.593405-05:
      DOI: 10.1002/eco.1826
       
  • Diatoms as indicators of fine sediment stress
    • Authors: J. Iwan Jones; Theresa A. Douthwright, Amanda Arnold, Chas P. Duerdoth, John F. Murphy, Francois K. Edwards, James L. Pretty
      Abstract: Excessive delivery of fine sediments to water bodies has a detrimental impact on the biotic elements used for water body status classification. Although diatoms are typically used to assess stress from eutrophication, as fine sediment has the potential to impact diatoms in many ways, it is not surprising that an index based on benthic diatom assemblages has been proposed: the relative abundance of motile species. This measure is based on the fact that many raphid diatom species are capable of migrating through deposited sediment to avoid negative impacts. However, the use of such an index has yet to be fully tested.Various data analysis techniques were used to explore how indices based on diatom assemblages (related to eutrophication and siltation), diatom species, the traits motility, and nutrient affinity responded to a gradient of percentage cover of fine sediment. Although diatom species showed marked variation in their affinity for percentage cover of fine sediment, the relationship between motility (both percent motile and the trait motility) and deposited fine sediment is not sufficiently strong to be used as a reliable indicator of fine sediment stress. We present an approach, which could potentially be used to develop a new index (diatom indicator of sediment conditions) on the basis of the response of diatoms to fine sediment, but caution that this index requires further development before use. Despite the hydromorphology having considerable potential to affect benthic diatoms, existing indices designed to assess eutrophication were robust to hydromorphological modification, reducing the possibility of false diagnosis of impacts.
      PubDate: 2017-02-22T07:05:28.162186-05:
      DOI: 10.1002/eco.1832
       
  • An assessment of direct and indirect effects of two herbicides on aquatic
           communities
    • Authors: Simone Hasenbein; Sharon P. Lawler, Richard E. Connon
      Abstract: Herbicides are often detected in watersheds at concentrations that are toxic to phytoplankton, potentially causing indirect effects on higher trophic organisms. The long-term effects of 5 applications over 30 d of binary mixtures of the herbicides diuron and hexazinone were assessed at “low” and “high” concentrations typically found in the environment, using mesocosms. Sixteen of 95 phytoplankton taxa, 3 of 18 zooplankton taxa, and 6 of 14 macroinvertebrate taxa responded negatively to contaminant exposures. Herbicide applications altered the phytoplankton community structure. Relative abundance of Cyanophyceae decreased following 5 applications from 52.1% in the control to 37.3% in the low treatment and to 25.9% in the high treatment, while Chlorophyceae increased to 50.6% in the low treatment and to 61.7% in the high treatment compared with the control (39.7%). Chlorophyceae had the greatest number of affected species (8), whereas 1 species within the Cyanophyceae was negatively affected on more than 1 sampling day. Further, chlorophyll a was reduced on 4 and 5 d out of the 8 total sampling days in the low and high treatments, respectively, compared with the control. These results highlight that integrating multiple taxa and contaminants with long-term exposures in ecological risk assessments of herbicides can facilitate the ability to make predictive and mechanistic generalizations about the role of herbicides in shaping patterns of species abundance in natural systems. Environ Toxicol Chem 2017;9999:1–11. © 2017 SETAC
      PubDate: 2017-02-21T13:46:26.484183-05:
      DOI: 10.1002/etc.3740
       
  • The ecohydrological vulnerability of a large inland delta to changing
           regional streamflows and upstream irrigation expansion
    • Authors: Elmira Hassanzadeh; Amin Elshorbagy, Ali Nazemi, Timothy D. Jardine, Howard Wheater, Karl-Erich Lindenschmidt
      Abstract: Future climate change and anthropogenic interventions can alter historical streamflow conditions and consequently degrade the health and biodiversity of freshwater ecosystems. Future ecohydrological threats, however, are difficult to quantify using the cascade of climate and hydrological models due to various uncertainties involved. This study instead uses a fully bottom-up approach to evaluate the ecohydrological vulnerability of the Saskatchewan River Delta (SRD), the largest inland delta in North America, to changing streamflow regime and irrigation expansion. An ensemble of perturbed streamflow sequences, along with scenarios of current and expanded irrigation, was generated and fed into a regional water resource system model. Results show that the streamflow regime in the delta is more sensitive to upstream changes in annual flow volume than peak flow timing and/or irrigation expansion. The sensitivity to changes in flow volume, however, may be intensified when combined with changes in peak timing. Shifts in the upstream peak flow timing can alter the magnitude and timing of peak flow to the delta, with prime importance to aquatic biota that are adapted to historical rhythmicity in peak flows and timing. Irrigation expansion decreases the magnitude and frequency of the peak flows, alters the frequency of average and low flows, and slightly shifts the timing of the mean annual peak flow in the SRD. This can lead to isolation of lakes and wetlands from the main stream. Our results highlight the ecohydrological vulnerability of the SRD under potential changing conditions and can assist in proposing adaptation policies to protect this ecosystem.
      PubDate: 2017-02-17T05:15:42.385045-05:
      DOI: 10.1002/eco.1824
       
  • Projecting impacts of climate change on habitat availability in a
           macrophyte dominated Chalk River
    • Authors: A. R. House; J. R. Thompson, C. Roberts, K. Smeth, G. Old, M. C. Acreman
      Abstract: Climate change will impact fluvial ecosystems through changes in the flow regime. Physical habitat is an established measure of a river's ecological status when assessing changes to flow. Yet, it requires extensive datasets, is site specific, and does not account for dynamic processes; shortcomings that the use of hydrological and hydraulic models may alleviate. Here, simulated flows along a 600 m reach of the River Lambourn, Boxford, UK, were extracted from the 1D MIKE 11 hydraulic component of an integrated MIKE SHE model of the Centre for Ecology & Hydrology River Lambourn Observatory. In-channel seasonal macrophyte growth and management through cutting alter water levels, represented in the hydraulic model by manipulating channel bed roughness (Manning's n). Assessment of climate change used outputs from the UK Climate Projections 2009 ensemble of global climate models for the 2080s. River discharge outputs were disaggregated to provide velocity and depth profiles across 41 cross sections along the reach. These were integrated with habitat suitability criteria for brown trout (Salmo trutta) to generate a measure of available physical habitat. The influence of macrophyte growth caused the habitat-discharge relationship to be unusable in evaluating the sensitivity of brown trout to flow changes. Instead, projected time series were used to show an overall reduction in habitat availability, more for adult than juvenile trout. Results highlighted the impact of weed cutting, and its potential role in mitigating both flood risk and the ecological impacts of climate change. The use of a hydraulic model to assess physical habitat availability has worldwide applicability.
      PubDate: 2017-02-17T05:11:58.81739-05:0
      DOI: 10.1002/eco.1823
       
  • Inhibition of immune responses and related proteins in Rhamdia quelen
           exposed to diclofenac
    • Authors: João L.C. Ribas; James P. Sherry, Aleksander R. Zampronio, Helena C. Silva de Assis, Denina B.D. Simmons
      Abstract: Nonsteroidal anti-inflammatory drugs are among the most widely detected pharmaceuticals in surface water worldwide. The nonsteroidal anti-inflammatory drug diclofenac is used to treat many types of pain and inflammation. Diclofenac's potential to cause adverse effects in exposed wildlife is a growing concern. To evaluate the effects of waterborne diclofenac on the immune response in Rhamdia quelen (South American catfish), fish were exposed to 3 concentrations of diclofenac (0.2, 2.0, and 20.0 μg/L) for 14 d. Some of the exposed fish were also given an intraperitoneal injection on day 14 of 1 mg/kg of carrageenan to evaluate cell migration to the peritoneum. Total blood leukocyte count and carrageenan-induced leukocyte migration to the peritoneal cavity, particularly of polymorphonuclear cells, were significantly affected for all diclofenac exposure groups. Nitric oxide production was significantly reduced in the diclofenac-treated fish. Plasma and kidney proteins were analyzed by means of liquid chromatography–tandem mass spectrometry in a shotgun proteomic approach. In both plasma and kidney of diclofenac-exposed R. quelen, the expression of 20 proteins related to the inflammatory process, nitric oxide production, leukocyte migration, and the complement cascade was significantly altered. In addition, class I major histocompatibility complex was significantly decreased in plasma of diclofenac-treated fish. Thus, waterborne exposure to diclofenac could lead to suppression of the innate immune system in R. quelen. Environ Toxicol Chem 2017;9999:1–16. © 2017 SETAC
      PubDate: 2017-02-16T14:20:25.684427-05:
      DOI: 10.1002/etc.3742
       
  • Difference in response of water use to evaporative demand for codominant
           diffuse-porous versus ring-porous tree species under N addition in a
           temperate forest
    • Authors: Lei Ouyang; Ping Zhao, Liwei Zhu, Zhenzhen Zhang, Xiuhua Zhao, Guangyan Ni
      Abstract: In this study, we explored the impacts of nitrogen (N) addition on water transpiration of codominant trees with different wood anatomy and their response of water use to varying vapor pressure deficit (VPD). Three tree species, diffuse-porous Liquidambar formosana Hance (maple), ring-porous Quercus variabilis Blume (cork oak), and Quercus acutissima Carruth (sawtooth oak), were selected for this research. These temperate forest trees grow in a climatic transitional zone located in Henan Province of Central China, and have been under N addition treatments of different levels since April 2013. The N treatments include control, low N (25 kg N ha−1 year−1), and high N levels (50 kg N ha−1 year−1). The measured data of stem sap flow from April to October 2015 showed that maple trees used more water than oak trees and N addition generally decreased the water transport of maple and sawtooth oak but induced no significant change of water transpiration for cork oak. Water use in maple increased with VPD, whereas relatively flat response for both oaks was observed, suggesting a much stricter stomatal control. Under N addition, water transport in all tree species showed a significant decline in the wet period (August), during which there were more precipitation and cloudy days than in dry May when VPD is >1.80 kPa. However, changes of vessel size, hydraulic conductivity, and root biomass that are associated with N addition for both ring- and diffuse-porous species remain unknown and require further investigation.
      PubDate: 2017-02-08T02:12:16.099906-05:
      DOI: 10.1002/eco.1829
       
  • Regional-scale extremes in river discharge and localised spawning stock
           abundance influence recruitment dynamics of a threatened freshwater fish
    • Authors: Zeb Tonkin; Joanne Kearns, Jarod Lyon, Stephen Balcombe, Alison King, Nick Bond
      Abstract: Highly variable recruitment is common for many riverine fish species, governed by a wide range of biotic and abiotic drivers that operate at local and regional scales. The dynamics and drivers of recruitment for many Australian freshwater fish species, particularly those that are rare and long-lived, are relatively undescribed. This study describes the recruitment dynamics of an endangered riverine fish, Macquarie perch Macquaria australasica, across five isolated populations from south-eastern Australia, and relates these dynamics to drivers that vary at local and regional scales. We hypothesised large flow events occurring during the core egg and larval period would be negatively associated with recruitment strength and that recruitment patterns across populations would fluctuate in synchrony in response to extremes in river discharge resulting from regional-scale climatic patterns.Discharge during the core egg and larval period, which was highly correlated across the region; and a local scale variable, spawning stock abundance, were the covariates most important in explaining recruitment strength. We also observed synchronised patterns in recruitment across our populations, thus conforming to predictions of the Moran effect (environmental synchrony). The findings suggest most remnant populations of Macquarie perch, which are now predominantly isolated within small tributary systems characterised by highly variable flows, face a heightened risk of poor recruitment periods, particularly under climate change predictions. The synchronised patterns in recruitment suggests threatened freshwater fishes like Macquarie perch with highly fragmented isolated populations, have an increased risk of the regional population becoming imperilled, thus, the need for a coordinated multijurisdictional conservation approach.
      PubDate: 2017-02-02T09:05:33.497955-05:
      DOI: 10.1002/eco.1842
       
  • Classification of California streams using combined deductive and
           inductive approaches: Setting the foundation for analysis of hydrologic
           alteration
    • Authors: Matthew I. Pyne; Daren M. Carlisle, Cristopher P. Konrad, Eric D. Stein
      Abstract: Regional classification of streams is an early step in the Ecological Limits of Hydrologic Alteration framework. Many stream classifications are based on an inductive approach using hydrologic data from minimally disturbed basins, but this approach may underrepresent streams from heavily disturbed basins or sparsely gaged arid regions. An alternative is a deductive approach, using watershed climate, land use, and geomorphology to classify streams, but this approach may miss important hydrological characteristics of streams. We classified all stream reaches in California using both approaches. First, we used Bayesian and hierarchical clustering to classify reaches according to watershed characteristics. Streams were clustered into seven classes according to elevation, sedimentary rock, and winter precipitation. Permutation-based analysis of variance and random forest analyses were used to determine which hydrologic variables best separate streams into their respective classes. Stream typology (i.e., the class that a stream reach is assigned to) is shaped mainly by patterns of high and mean flow behavior within the stream's landscape context. Additionally, random forest was used to determine which hydrologic variables best separate minimally disturbed reference streams from non-reference streams in each of the seven classes. In contrast to stream typology, deviation from reference conditions is more difficult to detect and is largely defined by changes in low-flow variables, average daily flow, and duration of flow. Our combined deductive/inductive approach allows us to estimate flow under minimally disturbed conditions based on the deductive analysis and compare to measured flow based on the inductive analysis in order to estimate hydrologic change.
      PubDate: 2017-02-02T05:40:32.296907-05:
      DOI: 10.1002/eco.1802
       
  • So which Gordon Hodgeon are we going to talk about?
    • Authors: Michael Torbe
      Abstract: A brief personal summary and reflection on Gordon Hodgeon's career and personality as man, educationalist and poet, together with his impact on people around him.
      PubDate: 2017-02-02T04:10:29.998022-05:
      DOI: 10.1111/eie.12124
       
  • Dissimilarity in the riparian arthropod communities along surface water
           permanence gradients in aridland streams
    • Authors: Eric K. Moody; John L. Sabo
      Abstract: The riparian areas around streams and rivers are often thought of as distinct habitats with unique species. Research on riparian zones has traditionally focused on those bordering perennial waterways; thus, we know much less about riparian species supported by intermittent and ephemeral streams. As nonperennial streams make up the vast majority of stream channels in many landscapes, we aimed to investigate how surface water permanence affects riparian communities. We focus on riparian ground-dwelling arthropods, a group that often depends on resources derived from surface and/or ground water. We sampled riparian ground-dwelling arthropods along surface water permanence gradients in 3 replicated stream channels in southeastern Arizona to assess patterns in diversity and community similarity. We found that alpha diversity did not differ between reach types, but high species turnover led to significant community dissimilarity among perennial, intermittent, and ephemeral riparian zones. Further, intermittent and ephemeral riparian zones harbored more unique species not found at other reach types than did perennial reaches. These patterns were strongest during the dry season, when intermittent and ephemeral reaches are most likely to lack surface water. Our results suggest not only that the riparian zones of nonperennial streams host equivalent arthropod diversity to their perennial counterparts but also that these communities have little overlap with those at perennial reaches. As a result, intermittent and ephemeral stream channels should receive greater consideration than they currently do in efforts to conserve regional biodiversity.
      PubDate: 2017-01-25T00:55:32.349514-05:
      DOI: 10.1002/eco.1819
       
  • Microsite and grazing intensity drive infiltration in a semiarid woodland
    • Authors: Sumiya Vandandorj; David J. Eldridge, Samantha K. Travers, James Val, Ian Oliver
      Abstract: Human activities such as vegetation removal and overgrazing that result in changes in land cover have substantial impacts on ecosystem processes, including the infiltration of water. Different land cover types (microsites) vary in their capacity to conduct water, but the extent to which infiltration is affected by different herbivores or microsites is largely unknown. We examined the effects of grazing and microsite on infiltration in two extensive woodland communities in semiarid eastern Australia that vary in current condition. Poor condition sites had lower steady-state infiltration under ponding than either average or good condition sites, and this effect was consistent across the two communities. Ponded infiltration and sorptivity beneath grasses, shrubs or trees were about twice that on bare soil, and this corresponded to greater indices of macroporosity. Structural equation modelling showed that shrubs, trees, and grasses had strong positive effects on sorptivity and steady-state infiltration under ponding, whereas grazing had generally negative effects. The suppressive effects of grazing on soil hydrological processes were mainly due to cattle grazing. The positive effects of grasses, shrubs, and trees on hydrology were twice as strong as the negative effects of grazing. Our results also suggest that prolonged overgrazing that leads to reductions in grass cover is likely to have a synergistic reduction in hydrological function in these woodlands by reducing the cover of highly conductive patches and by reducing the extent of macropores.
      PubDate: 2017-01-25T00:55:28.816647-05:
      DOI: 10.1002/eco.1831
       
  • Thawing seasonal ground ice: An important water source for boreal forest
           plants in Interior Alaska
    • Authors: Jessica M. Young-Robertson; Kiona Ogle, Jeffrey M. Welker
      Abstract: Little is known about the ecological impacts of permafrost degradation on water fluxes in boreal ecosystems, such as those in Interior Alaska. Low plant water stress suggests a reliance on a diversity of water sources. In addition to rainfall, we hypothesize that deep soil water derived from thawing seasonal ground ice (TSGI) supports plants during dry periods. We analyzed water stable isotopes from soils, plants, ice, and rain collected from stable and unstable permafrost sites. We found that TSGI provides a background water source for plants during wet years (at least 10–20%) and a stable source during dry years (at least 30–50%) and early in the growing season (60–80% in wet and dry years). Plant water uptake patterns “track” the soil thawing front, using deep and shallow layers in wet years and deep layers during dry years. This plasticity allows boreal plants to cope with seasonal drought and exploit available water sources. The availability of TGSI depends on the amount of rainfall the prior year and on permafrost stability. Thawing permafrost may reduce the buffering capacity of TGSI due to less seasonal ice from greater drainage and/or a deeper active layer. This study demonstrates the importance of two buffering mechanisms for plants to cope with rainfall variability within boreal forest underlain by permafrost—availability of TSGI and plasticity in water uptake patterns. We suggest that plant utilization of stored water may be why evapotranspiration in northern latitudes can exceed growing season precipitation.
      PubDate: 2017-01-25T00:50:55.952618-05:
      DOI: 10.1002/eco.1796
       
  • Long-term cottonwood establishment along the Green River, Utah, USA
    • Authors: M. L. Scott; M. E. Miller
      Abstract: Cottonwood (Populus spp.) riparian forest and woodlands provide valuable ecological goods and services, especially in arid and semiarid regions of North America. Successful establishment and survival for cottonwoods requires bare, moist alluvium that is relatively safe from fluvial disturbance. These are restrictive requirements in dry regions. Cottonwoods can survive for three to four centuries and thus may provide a long-term record of specific fluvial and geomorphic events. We used C14 analysis and ring counts of cottonwood stems to document a long-term record of cottonwood establishment. We related this record to the century-long gage record at Green River, Utah along with historical photos and paleoflood records. Radiometric carbon dating and ring counts suggest some cottonwood stems established on high alluvial deposits following large floods as early as the late 1600s through the late 1800s. Cottonwoods also established on inset floodplain surfaces following sustained decreases in peak flows resulting from climatic drought and the closing of Flaming Gorge Dam. Finally, establishment occurred on both higher post-dam flood deposits as well as low, active channel surfaces following floods and during a series of low flow years. With continued peak-flow reduction, cottonwood recruitment will likely be restricted to spatially limited, lower elevation surfaces and subjected to competition from an array of herbaceous and woody riparian species.
      PubDate: 2017-01-25T00:50:50.505704-05:
      DOI: 10.1002/eco.1818
       
  • Managing native fish communities during a long-term drought
    • Authors: Lee J. Baumgartner; Ian J. Wooden, John Conallin, Wayne Robinson, Jason D. Thiem
      Abstract: Ecological communities are adapted to extreme hydrological conditions. River regulation can, at times, exacerbate stressors such as drought and flood that threaten population persistence. Conversely, river infrastructure offers a means to deliver water for environmental benefit. Thus knowledge of the life history requirements of native fish, including location-specific community structure during drought conditions, is required to inform the management of aquatic ecosystems for native fish in regulated systems. During a severe drought, fish community sampling at 30 sites was undertaken in the Edward–Wakool (E–W) river system, an anabranch system of the Murray River, southeast Australia, to provide recommendations into the current management under drought and for future planning. Fish from the E–W system demonstrated diverse responses to drought conditions. Some species recruited under drought conditions, whilst others were restricted in distribution to a few key refuge habitats. The ability for fish species to persist in the long term depends largely on developing appropriate management strategies that both protect critical habitat and sustain biological function. Both situations require a combination of advance planning and reactionary monitoring, which is adaptively used to minimise impacts. Here, we present a number of practical solutions, based on experience from the E–W system, that are applicable to other regulated river systems. It is essential that agencies responsible for drought management ensure appropriate plans are developed ready for implementation in advance of future drought events.
      PubDate: 2017-01-25T00:50:36.969046-05:
      DOI: 10.1002/eco.1820
       
  • The impact of drought on sap flow of cooccurring Liquidambar formosana
           Hance and Quercus variabilis Blume in a temperate forest, Central China
    • Authors: Liwei Zhu; Yanting Hu, Xiuhua Zhao, Xiaomin Zeng, Ping Zhao, Zhenzhen Zhang, Yuxi Ju
      Abstract: Diffuse- and ring-porous species with different vessel structures exhibited contrasting water use strategies for adapting to water stress. The sap flow rates of two tree species (diffuse-porous: Liquidambar formosana Hance; and ring-porous: Quercus variabilis Blume) under different environmental conditions were monitored in a temperate forest in the south of Henan Province, Central China. The mechanisms underlying the contrasting water use strategies in response to drought stress were explored by analysing the correlation of sap flow per unit sapwood area (Fd) with vapour pressure deficit and the contribution of nocturnal Fd to total water use under different soil water contents. The results showed that the Fd of Q. variabilis decreased under drought conditions, whereas that of L. formosana increased. Under drought stress, stronger stomatal control was shown for both tree species. Stomatal regulation and changes of leaf area jointly led to constant sap flow per unit leaf area (JL) across the seasons for Q. variabilis. The seasonal variations in the ratio of nocturnal mean Fd to total Fd were consistent with those in the daytime mean JL for both tree species. Nocturnal sap flow played a critical role in the increased water use of diffuse-porous species, L. formosana, under drought conditions. Our study highlights the importance of nocturnal sap flow for water use by forest species. This finding provides insights for future studies of the water cycle in forest ecosystems and demonstrates that such studies should take into account the nocturnal physiological processes of plants.
      PubDate: 2017-01-25T00:50:28.833348-05:
      DOI: 10.1002/eco.1828
       
  • Ecohydrological transformation in the Dry Chaco and the risk of dryland
           salinity: Following Australia's footsteps?
    • Authors: Victoria A. Marchesini; Raúl Giménez, Marcelo D. Nosetto, Esteban G. Jobbágy
      Abstract: During the last century, the massive conversion of Australian dry forests to crops and pastures triggered the massive soil and groundwater degradation process known as dryland salinity. Currently, South American Chaco's dry forests are undergoing a similar transformation, leading global deforestation rates. The goal of this study was to review existing ecohydrological information about natural and cultivated systems in the Chaco to assess the dryland salinity risks. We review deep soil water, salt stocks, and groundwater recharge from agriculture or native dry forests stands located in a precipitation range of 450–1100 mm. We complement this with water table level records and geoelectric profiles together with personal observations. We use data from 15 Australian studies for comparison. Strong salt leaching, especially after 20 years of forest clearance, indicates the onset of deep drainage following forest conversion to agriculture in the Dry Chaco. Water stocks were more than double in the cleared stands compared to their dry forest pairs, and recharge rates were up to two order magnitude higher in agricultural areas. Although lower atmospheric salt deposition, younger sediments, and relatively high water-consuming agricultural systems in the Dry Chaco attenuate salinization risks compared to Australia, the very flat topography and related shallow water table levels of the South American region could make groundwater recharge and salt mobilization processes more widespread and difficult to manage. The lack of awareness among the general public, farmers, and decision makers about this issue amplifies the problem, making land management plans for the Argentine dry forest territories essential.
      PubDate: 2017-01-25T00:45:39.182427-05:
      DOI: 10.1002/eco.1822
       
  • Quantifying the benefits of urban forest systems as a component of the
           green infrastructure stormwater treatment network
    • Authors: Eric Kuehler; Jon Hathaway, Andrew Tirpak
      Abstract: The use of green infrastructure for reducing stormwater runoff is increasingly common. One under-studied component of the green infrastructure network is the urban forest system. Trees can play an important role as the “first line of defense” for restoring more natural hydrologic regimes in urban watersheds by intercepting rainfall, delaying runoff, infiltrating, and transpiring captured stormwater. However, inadequate research quantifying the urban tree contribution to rainfall/runoff processes limits their promotion by stormwater managers. The purpose of this literature review is to highlight the limited research performed, document areas of need for quantifying the benefits of urban trees for stormwater management, and provide a basis for providing credits for trees in stormwater designs. Recent research has shown that urban trees can retain a sizable volume of annual rainfall in their crowns, delay the flow of stormwater runoff, substantially increase the infiltration capacity of urban soils, and provide transpiration of sequestered runoff for additional stormwater storage. Tree canopy effectiveness is highest during short, low-intensity storms and lower as rainfall volume and intensity increases. While soils are the best medium to store and filter stormwater, trees may be integrated with other runoff reduction strategies to bring more natural hydrologic processes to urban watersheds by taking advantage of multiple points of retention. Gaps remain in the body of research, but there is a basis for considering trees an integral part of the watershed-scale green infrastructure network that helps reduce the volume and intensity of urban stormwater runoff.
      PubDate: 2017-01-25T00:45:32.118897-05:
      DOI: 10.1002/eco.1813
       
  • Regional variation in streamflow drivers across a continental climatic
           gradient
    • Authors: Ralph Trancoso; Stuart Phinn, Tim R. McVicar, Joshua R. Larsen, Clive A. McAlpine
      Abstract: Streamflow characteristics are driven by specific flow-generation mechanisms, which are in turn determined by the biophysical properties of catchments. They provide important environmental services for society and ecosystems, regulating water supply and quality, flood mitigation, and the biological diversity of aquatic ecosystems. This study investigates how the drivers of streamflow characteristics vary at the level of regional management (regional [104 km2] and continental scales [107 km2]) in eastern Australia. Three hydrological signatures were used to represent streamflow characteristics: runoff coefficient, baseflow index, and zero flow ratio. Long-term streamflow data and 24 spatially distributed biophysical properties from 354 catchments in eastern Australia were analysed with random forest and generalized additive beta regression models to determine the dominant drivers of streamflow characteristics. We found that the main drivers of streamflow characteristics cannot be generalized from region to region and that specific biophysical variables govern their spatial variability. However, some important drivers such as the dryness index and the fraction of photosynthetically active radiation from vegetation explain the variability of streamflow characteristics at both regional and continental scales with differing importance. Our findings also suggest that soil properties have a significant effect on streamflow characteristics at regional scales. However, the relative importance of these soil properties varies among regions depending on the streamflow characteristics. This paper demonstrates that the drivers of streamflow characteristics are scale and region dependent, and biogeographically different regions have specific mechanisms governing streamflow. It opens an avenue to better connect the management perspectives of ecology and hydrology.
      PubDate: 2017-01-19T03:45:48.321019-05:
      DOI: 10.1002/eco.1816
       
  • Associations of event-scale flow hydrology with fish richness in
           urbanizing Canadian watersheds of Lake Ontario
    • Authors: M.P. Trudeau; A. Morin
      Abstract: Urbanization is associated with declines in aquatic biodiversity and changes to flow regimes. This empirical research examined high temporal resolution (15 min) hydrologic records and associations with fish species richness in eight river systems in the Toronto region, Canada. The dataset spanned approximately five decades and covered the annual post-freshet period to mid-November. The high-temporal resolution flow records allowed estimation of flow acceleration (a measure of the rate of change in flow) in response to rain events. Maximum rising limb event flow acceleration and skew in instantaneous runoff explained a higher proportion of variation than percent urban land use in empirical models with long-term fish records. Models fit using only the most recent decade of records did not produce the same results, likely indicating that analyses of flow with fish diversity require sufficient range in flow conditions for the statistical signals to be detected. Historic fish data are difficult to obtain and pose analytical challenges due to bias and inconsistent collection methods. Despite the data limitations, the study results point to the need for more research into potential causal factors contributing to negative fish richness in urbanizing watercourses with periods of high flow acceleration.
      PubDate: 2017-01-10T07:15:48.740028-05:
      DOI: 10.1002/eco.1807
       
  • Strategies trees use to overcome seasonal water limitation in an
           agroforestry system in semiarid West Africa
    • Authors: A. Bargués Tobella; N.J. Hasselquist, H.R. Bazié, G. Nyberg, H. Laudon, J. Bayala, U. Ilstedt
      Abstract: Agroforestry parklands, in which annual crops are grown under scattered mature trees, constitute the most prevalent farming system in semiarid West Africa, covering vast areas of land. The most dominant tree species in these systems is Vitellaria paradoxa, an indigenous tree to West Africa. Despite the importance of this tree in the region, no study to our knowledge has examined its sources and patterns of water uptake. In this study, we used oxygen stable isotopes at natural abundance levels to investigate water sources used by V. paradoxa both in the dry and wet season in an agroforestry parkland in Burkina Faso. We found that during the wet season soil moisture was highest near the soil surface (
      PubDate: 2017-01-10T07:15:41.990829-05:
      DOI: 10.1002/eco.1808
       
  • Shifts in landscape ecohydrological structural–functional relationship
           driven by experimental manipulations and ecological interactions
    • Authors: Oren Hoffman; Hezi Yizhaq, Bertrand Boeken
      Abstract: Vegetation structure and patchiness are central controllers of ecohydrological function in semiarid regions. The feedback interactions between vegetation patchiness and water redistribution make semiarid ecosystems sensitive to state-shifts, where nonlinearities appear in the structure–function correlations. Hydrological connectivity of runoff sources is functionally important for source–sink interactions over a range of spatial scales and plays a key role in ecosystem state-shifts. Accordingly, the study of the functional responses of ecosystems to changes in connectivity is important for assessing the system's resilience in response to drivers of degradation. We used runoff data collected over 18 years in experimentally manipulated plots to study both the primary functional response to the manipulations and the changes in both structure and function over two decades. By comparing simultaneous changes in woody and herbaceous cover, biocrust cover and connectivity, and runoff yield, we examined the interactions among the different cover classes and assessed the functional consequences of these interactions. The manipulated changes in vegetation and biocrust cover caused large differences in runoff yields, with positive correlation between biocrust cover and runoff. However, changes in vegetation patterns reduced these differences, as the spread of herbaceous plant cover, at the expense of biocrust and woody cover, caused a shift in the cover–runoff relationship. The landscape was resilient to degradation due to rapid shrub growth in locations of high biocrust cover. On the other hand, a positive feedback of herbaceous plant cover replacing shrub cover caused a state-shift, likely driven by a combination of drought recurrence and cessation of grazing.
      PubDate: 2017-01-10T07:15:28.875616-05:
      DOI: 10.1002/eco.1806
       
  • Issue Information
    • Pages: 1 - 4
      PubDate: 2017-03-16T01:17:31.815578-05:
      DOI: 10.1111/eie.12116
       
  • Editorial: Fit for purpose: lessons in assessment and learning
    • Authors: Ann Harris
      Pages: 5 - 11
      PubDate: 2017-03-16T01:17:31.290531-05:
      DOI: 10.1111/eie.12134
       
  • Remember me'
    • Authors: Jo Carrington
      Pages: 12 - 13
      PubDate: 2017-03-16T01:17:30.111248-05:
      DOI: 10.1111/eie.12113
       
  • Assessing reading development through systematic synthetic phonics
    • Authors: Jonathan Glazzard
      Pages: 44 - 57
      Abstract: This narrative literature review evaluates the effectiveness of synthetic phonics in comparison with analytic phonics. It presents the key research findings and offers a critical appraisal of this research. Primary schools have developed a variety of assessment processes which assess pupils’ knowledge and skills in synthetic phonics. It is through using these assessment tools that gaps in pupils’ knowledge and skills are identified and these gaps then form the basis of subsequent synthetic phonics interventions. The article concludes by arguing that a more detailed assessment framework may be required for the purpose of assessing children's reading development than the model which schools currently adopt.
      PubDate: 2017-03-16T01:17:31.996869-05:
      DOI: 10.1111/eie.12125
       
  • What does a good one look like? Marking A-level English scripts in
           relation to others
    • Authors: Victoria Elliott
      Pages: 58 - 75
      Abstract: This article explores the use of representativeness as a guide to examining at English A-level through an analysis of two training days on two different modules. Representativeness is a cognitive heuristic which guides decision-making essentially by asking ‘how much does this example look as if it belongs to this class of things?’ A number of representative characteristics emerged during the training meetings including length, ‘adult’ writing and quality of written communication. The relation between representativeness and the mark scheme is also explored.
      PubDate: 2017-03-16T01:17:30.161182-05:
      DOI: 10.1111/eie.12133
       
  • Digital Ensemble: The ENaCT design-based research framework for
           technology-enhanced embodied assessment in English education
    • Authors: Eilis Flanagan; Tony Hall
      Pages: 76 - 99
      Abstract: This article outlines the ENaCT educational design for Digital Ensemble, an innovative approach to English assessment integrating drama pedagogy with mobile computing (e.g. iPad). ENaCT represents the key themes that framed and informed the research: ensemble, narrative, collaboration and technology. Starting with ENaCT as a prototype concept design for the development and evaluation of technology-enhanced embodied assessment in English, the research developed and refined the model through collaborative cycles of design with post-primary schools. The design-based research study reported here was undertaken in three significant design iterations, totalling 15 weeks and 85 teaching hours. 131 Irish Senior Cycle students, aged 15 to 17 participated: 45, 46 and 45 pupils respectively in iterations one, two and three. Two teachers participated throughout. The article outlines for English teachers and educational designers the adaptable ENaCT framework for Digital Ensemble, including design and assessment criteria and evaluation rubrics, illustrated by exemplars of pupils’ work.
      PubDate: 2017-03-16T01:17:31.450294-05:
      DOI: 10.1111/eie.12136
       
  • The Work of the Course: validity and reliability in assessing English
           Literature
    • Authors: John Hodgson; Bill Greenwell
      Pages: 100 - 111
      Abstract: This article reflects on the values and practices of a revolutionary UK A level (senior secondary) course that achieved a high degree of validity and reliability in assessing the study of English literature. John Hodgson and Bill Greenwell were involved in its teaching and assessment from an early stage, and Greenwell's comments on an early draft of the article have been incorporated. The practice of literary response enshrined in the course was based on a striking application of “personal response” to literature, gave students opportunities to show capability in studying and writing a range of literary styles and genres, and engaged teachers regionally and nationally in a developed professional community of practice. It remains a touchstone of quality as well as of innovation in English curriculum and assessment.
      PubDate: 2017-03-16T01:17:31.016102-05:
      DOI: 10.1111/eie.12132
       
  • Literacy and Education James Paul Gee Routledge (2015) ISBN:
           978-1-138-82604-5 £20.93 (paperback) £95.00 (hardback)
    • Authors: Andrew Burn
      Pages: 112 - 114
      PubDate: 2017-03-16T01:17:30.502955-05:
      DOI: 10.1111/eie.12130
       
  • The Discourse of Reading Groups: Integrating Cognitive and Sociocultural
           Perspectives David Peplow, Joan Swann, Paola Trimarco and Sara Whiteley
           Routledge (2016) ISBN 78-0415729697 £95.00 hardback
    • Authors: Marcello Giovanelli
      Pages: 115 - 118
      PubDate: 2017-03-16T01:17:31.886193-05:
      DOI: 10.1111/eie.12131
       
  • Call for Papers Spring 2019 Special Issue
    • Authors: Jenifer Smith; Mari Cruice
      Pages: 119 - 120
      PubDate: 2017-03-16T01:17:30.948655-05:
      DOI: 10.1111/eie.12135
       
  • Editorial Board and Table of Contents
    • Pages: 1121 - 1124
      PubDate: 2017-04-19T12:14:44.478627-05:
      DOI: 10.1002/etc.3818
       
  • In some places, in some cases, and at some times, harmful algal blooms are
           the greatest threat to inland water quality
    • Authors: Bryan W. Brooks; James M. Lazorchak, Meredith D.A. Howard, Mari-Vaughn V. Johnson, Steve L. Morton, Dawn A.K. Perkins, Euan D. Reavie, Geoffrey I. Scott, Stephanie A. Smith, Jeffery A. Steevens
      Pages: 1125 - 1127
      PubDate: 2017-04-19T12:14:38.607789-05:
      DOI: 10.1002/etc.3801
       
  • The mechanisms of nickel toxicity in aquatic environments: An adverse
           outcome pathway analysis
    • Authors: Kevin V. Brix; Christian E. Schlekat, Emily R. Garman
      Pages: 1128 - 1137
      Abstract: Current ecological risk assessment and water quality regulations for nickel (Ni) use mechanistically based, predictive tools such as biotic ligand models (BLMs). However, despite many detailed studies, the precise mechanism(s) of Ni toxicity to aquatic organisms remains elusive. This uncertainty in the mechanism(s) of action for Ni has led to concern over the use of tools like the BLM in some regulatory settings. To address this knowledge gap, the authors used an adverse outcome pathway (AOP) analysis, the first AOP for a metal, to identify multiple potential mechanisms of Ni toxicity and their interactions with freshwater aquatic organisms. The analysis considered potential mechanisms of action based on data from a wide range of organisms in aquatic and terrestrial environments on the premise that molecular initiating events for an essential metal would potentially be conserved across taxa. Through this analysis the authors identified 5 potential molecular initiating events by which Ni may exert toxicity on aquatic organisms: disruption of Ca2+ homeostasis, disruption of Mg2+ homeostasis, disruption of Fe2+/3+ homeostasis, reactive oxygen species–induced oxidative damage, and an allergic-type response of respiratory epithelia. At the organ level of biological organization, these 5 potential molecular initiating events collapse into 3 potential pathways: reduced Ca2+ availability to support formation of exoskeleton, shell, and bone for growth; impaired respiration; and cytotoxicity and tumor formation. At the level of the whole organism, the organ-level responses contribute to potential reductions in growth and reproduction and/or alterations in energy metabolism, with several potential feedback loops between each of the pathways. Overall, the present AOP analysis provides a robust framework for future directed studies on the mechanisms of Ni toxicity and for developing AOPs for other metals. Environ Toxicol Chem 2017;36:1128–1137. © 2016 SETAC
      PubDate: 2017-01-22T10:50:33.856894-05:
      DOI: 10.1002/etc.3706
       
  • A critical review of polycyclic aromatic hydrocarbon phototoxicity models
    • Authors: Solmaz Marzooghi; Dominic M. Di Toro
      Pages: 1138 - 1148
      Abstract: Polycyclic aromatic hydrocarbons (PAHs) are known to exhibit photo-induced toxicity. Hundreds to thousands of PAH parent and substituted compounds are found in the environment, and developing a predictive model applicable to a wide variety of PAHs and organisms is a necessary precursor to environmental risk assessments. There has been evolutionary progress in phototoxicity modeling since 1977. In the present study, a comprehensive review of the models developed to predict phototoxicity of PAHs is presented. The contributions of each of the models to the state of the art are discussed. The models are compared in terms of their scope of applicability to different organisms, PAHs, endpoints (median lethal time and median lethal concentration), and light conditions. The current state of the science that accounts for the key elements of phototoxicity modeling, including the differences in species sensitivity, the partitioning of PAHs into the target lipid of the organisms, and light absorption by the chemicals, as well as light exposure time and conditions, is discussed. In addition, the remaining issues that need to be addressed are explored: the effect of time-varying exposures to light and PAH concentrations, and the lack of a mechanistic understanding that can explain the failure of the Bunsen–Roscoe law of reciprocity. Environ Toxicol Chem 2017;36:1138–1148. © 2016 SETAC
      PubDate: 2017-02-02T14:40:27.219883-05:
      DOI: 10.1002/etc.3722
       
  • Risk of POP mixtures on the Arctic food chain
    • Authors: Sara Villa; Sonia Migliorati, Gianna Serafina Monti, Ivan Holoubek, Marco Vighi
      Pages: 1181 - 1192
      Abstract: The exposure of the Arctic ecosystem to persistent organic pollutants (POPs) was assessed through a review of literature data. Concentrations of 19 chemicals or congeneric groups were estimated for the highest levels of the Arctic food chain (Arctic cod, ringed seals, and polar bears). The ecotoxicological risk for seals, bears, and bear cubs was estimated by applying the concentration addition (CA) concept. The risk of POP mixtures was very low in seals. By contrast, the risk was 2 orders of magnitude higher than the risk threshold for adult polar bears and even more (3 orders of magnitude above the threshold) for bear cubs fed with contaminated milk. Based on the temporal trends available for many of the chemicals, the temporal trend of the mixture risk for bear cubs was calculated. Relative to the 1980s, a decrease in risk from the POP mixture is evident, mainly because of international control measures. However, the composition of the mixture substantially changes, and the contribution of new POPs (particularly perfluorooctane sulfonate) increases. These results support the effectiveness of control measures, such as those promulgated in the Stockholm Convention, as well as the urgent need for their implementation for new and emerging POPs. Environ Toxicol Chem 2017;36:1181–1192. © 2017 SETAC
      PubDate: 2017-01-05T00:05:34.992567-05:
      DOI: 10.1002/etc.3671
       
  • Effects of atrazine and chlorothalonil on the reproductive success,
           development, and growth of early life stage sockeye salmon (Oncorhynchus
           nerka)
    • Authors: Lindsay M. Du Gas; Peter S. Ross, Janessa Walker, Vicki L. Marlatt, Christopher J. Kennedy
      Pages: 1354 - 1364
      Abstract: The effects of 2 currently used commercial pesticide formulations on Pacific sockeye salmon (Oncorhynchus nerka), from fertilization to emergence, were evaluated in a gravel-bed flume incubator that simulated a natural streambed. Embryos were exposed to atrazine at 25 µg/L (low atrazine) or atrazine at 250 µg/L (high atrazine) active ingredient (a.i.), and chlorothalonil at 0.5 µg/L (low chlorothalonil) or chlorothalonil at 5 µg/L a.i. (high chlorothalonil) and examined for effects on developmental success and timing, as well as physical and biochemical growth parameters. Survival to hatch was reduced in the high chlorothalonil group (55% compared with 83% in controls), accompanied by a 24% increase in finfold deformity incidence. Reduced alevin condition factor (2.9–5.4%) at emergence and elevated triglyceride levels were seen in chlorothalonil-exposed fish. Atrazine exposure caused premature hatch (average high atrazine time to 50% hatch [H50] = 100 d postfertilization [dpf]), and chlorothalonil exposure caused delayed hatch (high chlorothalonil H50 = 108 dpf; controls H50 = 102 dpf). All treatments caused premature emergence (average time to 50% emergence [E50]: control E50 = 181 dpf, low chlorothalonil E50 = 175 dpf, high chlorothalonil E50 = 174 dpf, high atrazine E50 = 175 dpf, low atrazine E50 = 174 dpf), highlighting the importance of using a gravel-bed incubator to examine this subtle, but critical endpoint. These alterations indicate that atrazine and chlorothalonil could affect survival of early life stages of sockeye salmon in the wild. Environ Toxicol Chem 2017;36:1354–1364. © 2017 SETAC
      PubDate: 2017-03-02T08:55:31.70824-05:0
      DOI: 10.1002/etc.3753
       
  • Mercury in tunas and blue marlin in the North Pacific Ocean
    • Authors: Paul E. Drevnick; Barbara A. Brooks
      Pages: 1365 - 1374
      Abstract: Models and data from the North Pacific Ocean indicate that mercury concentrations in water and biota are increasing in response to (global or hemispheric) anthropogenic mercury releases. In the present study, we provide an updated record of mercury in yellowfin tuna (Thunnus albacares) caught near Hawaii that confirms an earlier conclusion that mercury concentrations in these fish are increasing at a rate similar to that observed in waters shallower than 1000 m. We also compiled and reanalyzed data from bigeye tuna (Thunnus obesus) and blue marlin (Makaira nigricans) caught near Hawaii in the 1970s and 2000s. Increases in mercury concentrations in bigeye tuna are consistent with the trend found in yellowfin tuna, in both timing and magnitude. The data available for blue marlin do not allow for a fair comparison among years, because mercury concentrations differ between sexes for this species, and sex was identified (or reported) in only 3 of 7 studies. Also, mercury concentrations in blue marlin may be insensitive to modest changes in mercury exposure, because this species appears to have the ability to detoxify mercury. The North Pacific Ocean is a region of both relatively high rates of atmospheric mercury deposition and capture fisheries production. Other data sets that allow temporal comparisons in mercury concentrations, such as pacific cod (Gadus macrocephalus) in Alaskan waters and albacore tuna (Thunnus alalunga) off the US Pacific coast, should be explored further, to aid in understanding human health and ecological risks and to develop additional baseline knowledge for assessing changes in a region expected to respond strongly to reductions in anthropogenic mercury emissions. Environ Toxicol Chem 2017;36:1365–1374. © 2017 SETAC
      PubDate: 2017-03-06T14:45:30.037947-05:
      DOI: 10.1002/etc.3757
       
 
 
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