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  Subjects -> POLITICAL SCIENCE (Total: 888 journals)
    - CIVIL RIGHTS (10 journals)
    - INTERNATIONAL RELATIONS (106 journals)
    - POLITICAL SCIENCE (748 journals)
    - POLITICAL SCIENCES: GENERAL (24 journals)

POLITICAL SCIENCE (748 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 281 Journals sorted alphabetically
A Contracorriente     Open Access   (Followers: 1)
Ab Imperio     Full-text available via subscription   (Followers: 1)
Acta Borealia: A Nordic Journal of Circumpolar Societies     Hybrid Journal   (Followers: 1)
Acta Politica Estica     Open Access  
Acta Universitatis Sapientiae, European and Regional Studies     Open Access   (Followers: 1)
Administrative Science Quarterly     Full-text available via subscription   (Followers: 146)
Affirmations : of the modern     Open Access   (Followers: 1)
AFFRIKA Journal of Politics, Economics and Society     Full-text available via subscription   (Followers: 1)
Africa Conflict Monitor     Full-text available via subscription   (Followers: 3)
Africa Insight     Full-text available via subscription   (Followers: 14)
Africa Institute Occasional Paper     Full-text available via subscription   (Followers: 2)
Africa Renewal     Free   (Followers: 5)
Africa Review : Journal of the African Studies Association of India     Hybrid Journal   (Followers: 1)
Africa Today     Full-text available via subscription   (Followers: 16)
African Affairs     Hybrid Journal   (Followers: 59)
African Conflict and Peacebuilding Review     Full-text available via subscription   (Followers: 11)
African Diaspora     Open Access   (Followers: 8)
African East-Asian Affairs     Open Access   (Followers: 6)
African Identities     Hybrid Journal   (Followers: 11)
African Journal of Democracy and Governance     Full-text available via subscription   (Followers: 4)
African Journal of Rhetoric     Full-text available via subscription   (Followers: 2)
African Renaissance     Full-text available via subscription   (Followers: 2)
African Yearbook of Rhetoric     Full-text available via subscription   (Followers: 1)
Africanus     Full-text available via subscription   (Followers: 2)
Afrique contemporaine : La revue de l'Afrique et du développement     Full-text available via subscription   (Followers: 2)
Agenda Política     Open Access  
Agenda: A Journal of Policy Analysis and Reform     Full-text available via subscription   (Followers: 1)
Agrarian South : Journal of Political Economy     Hybrid Journal   (Followers: 1)
Akademik İncelemeler Dergisi     Open Access   (Followers: 1)
Alternatives : Global, Local, Political     Hybrid Journal   (Followers: 16)
Altre Modernità     Open Access   (Followers: 3)
América Latina Hoy     Open Access   (Followers: 2)
American Communist History     Hybrid Journal   (Followers: 19)
American Foreign Policy Interests: The Journal of the National Committee on American Foreign Policy     Hybrid Journal   (Followers: 9)
American Journal of Political Science     Hybrid Journal   (Followers: 271)
American Political Science Review     Hybrid Journal   (Followers: 224)
American Political Thought     Full-text available via subscription   (Followers: 11)
American Politics Research     Hybrid Journal   (Followers: 26)
American Quarterly     Full-text available via subscription   (Followers: 16)
Anacronismo e Irrupción     Open Access  
Analecta política     Open Access  
Análise Social     Open Access   (Followers: 1)
Annales UMCS, Politologia     Open Access  
Annals of the American Academy of Political and Social Science     Hybrid Journal   (Followers: 41)
Annual Review of Economics     Full-text available via subscription   (Followers: 30)
Annual Review of Political Science     Full-text available via subscription   (Followers: 144)
AQ - Australian Quarterly     Full-text available via subscription   (Followers: 1)
Arabian Humanities     Open Access   (Followers: 2)
Arctic Review on Law and Politics     Open Access   (Followers: 1)
Arena Journal     Full-text available via subscription   (Followers: 1)
Asia & the Pacific Policy Studies     Open Access   (Followers: 15)
Asia Minor Studies     Open Access   (Followers: 2)
Asia Policy     Full-text available via subscription   (Followers: 6)
Asia-Pacific Journal : Japan Focus     Open Access   (Followers: 8)
Asia-Pacific Review     Hybrid Journal   (Followers: 13)
Asian Affairs: An American Review     Hybrid Journal   (Followers: 2)
Asian Journal of Comparative Politics     Hybrid Journal   (Followers: 4)
Asian Journal of Political Science     Hybrid Journal   (Followers: 16)
Asian Politics and Policy     Hybrid Journal   (Followers: 12)
Astropolitics: The International Journal of Space Politics & Policy     Hybrid Journal   (Followers: 10)
AUDEM : The International Journal of Higher Education and Democracy     Full-text available via subscription   (Followers: 10)
Aurora. Revista de Arte, Mídia e Política     Open Access  
Australasian Review of African Studies, The     Full-text available via subscription   (Followers: 2)
Australian Journal of International Affairs     Hybrid Journal   (Followers: 24)
Australian Journal of Political Science     Hybrid Journal   (Followers: 15)
Austrian Journal of Political Science     Open Access   (Followers: 2)
Balcanica Posnaniensia Acta et studia     Open Access  
Baltic Journal of European Studies     Open Access  
Bandung : Journal of the Global South     Open Access   (Followers: 1)
Basic Income Studies     Hybrid Journal   (Followers: 9)
Behavioral Sciences of Terrorism and Political Aggression     Hybrid Journal   (Followers: 16)
Beleid en Maatschappij     Full-text available via subscription   (Followers: 2)
BMC International Health and Human Rights     Open Access   (Followers: 6)
Brazilian Political Science Review     Open Access  
Brésil(s)     Open Access   (Followers: 1)
British Journal of Canadian Studies     Hybrid Journal   (Followers: 11)
British Journal of Political Science     Hybrid Journal   (Followers: 148)
British Journal of Politics and International Relations     Hybrid Journal   (Followers: 27)
British Politics     Hybrid Journal   (Followers: 12)
British Review of New Zealand Studies     Full-text available via subscription   (Followers: 3)
Brookings Papers on Economic Activity     Open Access   (Followers: 48)
Bulletin d'histoire politique     Full-text available via subscription   (Followers: 3)
Bustan     Hybrid Journal   (Followers: 1)
Cadernos de Estudos Sociais e Políticos     Open Access  
CADUS - Revista de Estudos de Política, História e Cultura     Open Access  
Cahiers de l'Urmis     Open Access   (Followers: 1)
Cahiers de Sciences politiques de l'ULg     Open Access  
California Journal of Politics and Policy     Hybrid Journal   (Followers: 1)
Cambio 16     Full-text available via subscription   (Followers: 5)
Cambridge Review of International Affairs     Hybrid Journal   (Followers: 18)
Canadian Foreign Policy Journal     Hybrid Journal   (Followers: 5)
Caucasus Survey     Hybrid Journal  
Central and Eastern European Review     Open Access   (Followers: 2)
Central Asian Affairs     Hybrid Journal  
Central Banking     Full-text available via subscription   (Followers: 8)
Central European Journal of Public Policy     Open Access   (Followers: 2)
China : An International Journal     Full-text available via subscription   (Followers: 16)
China perspectives     Open Access   (Followers: 11)
China Quarterly     Hybrid Journal   (Followers: 48)
China Report     Hybrid Journal   (Followers: 10)
China Review International     Full-text available via subscription   (Followers: 8)
China-EU Law Journal     Hybrid Journal   (Followers: 4)
Chinese Journal of Global Governance     Open Access   (Followers: 3)
Chinese Journal of International Politics     Hybrid Journal   (Followers: 9)
Chinese Studies     Open Access   (Followers: 6)
Cittadinanza Europea (LA)     Full-text available via subscription  
Civil Wars     Hybrid Journal   (Followers: 12)
Claremont-UC Undergraduate Research Conference on the European Union     Open Access  
Class, Race and Corporate Power     Open Access   (Followers: 1)
Cold War History     Hybrid Journal   (Followers: 15)
Commonwealth & Comparative Politics     Hybrid Journal   (Followers: 11)
Communication, Politics & Culture     Open Access   (Followers: 13)
Communist and Post-Communist Studies     Hybrid Journal   (Followers: 14)
Comparative Political Studies     Hybrid Journal   (Followers: 155)
Comparative Politics (Russia)     Open Access   (Followers: 5)
Comparative Strategy     Hybrid Journal   (Followers: 8)
Competition & Change     Hybrid Journal   (Followers: 10)
Conferences on New Political Economy     Full-text available via subscription   (Followers: 3)
Confines     Open Access  
Conflict and Society     Full-text available via subscription   (Followers: 1)
Conflict Management and Peace Science     Hybrid Journal   (Followers: 28)
Conflict Trends     Full-text available via subscription   (Followers: 9)
Conflict, Security & Development     Hybrid Journal   (Followers: 357)
Congress & the Presidency: A Journal of Capital Studies     Hybrid Journal   (Followers: 3)
Conjunctions. Transdisciplinary Journal of Cultural Participation     Open Access   (Followers: 3)
Constellations     Hybrid Journal   (Followers: 15)
Contemporary Italian Politics     Hybrid Journal   (Followers: 2)
Contemporary Japan     Hybrid Journal   (Followers: 5)
Contemporary Journal of African Studies     Full-text available via subscription   (Followers: 3)
Contemporary Political Theory     Hybrid Journal   (Followers: 37)
Contemporary Review of the Middle East     Full-text available via subscription   (Followers: 3)
Contemporary Security Policy     Hybrid Journal   (Followers: 15)
Contemporary Southeast Asia: A Journal of International and Strategic Affairs     Full-text available via subscription   (Followers: 20)
Contemporary Wales     Full-text available via subscription   (Followers: 3)
Contenciosa     Open Access  
Contexto Internacional     Open Access  
Cooperation and Conflict     Hybrid Journal   (Followers: 13)
CQ Researcher     Full-text available via subscription   (Followers: 2)
CQ Weekly     Full-text available via subscription  
Criterio Jurídico     Open Access  
Critical Asian Studies     Hybrid Journal   (Followers: 12)
Critical Review : A Journal of Politics and Society     Hybrid Journal   (Followers: 20)
Critical Review of International Social and Political Philosophy     Hybrid Journal   (Followers: 18)
Critical Reviews on Latin American Research     Open Access   (Followers: 3)
Critical Social Policy     Hybrid Journal   (Followers: 34)
Critical Studies on Terrorism     Hybrid Journal   (Followers: 26)
Cuadernos de historia de España     Open Access   (Followers: 4)
Cultura de Paz     Open Access  
Cultural Critique     Full-text available via subscription   (Followers: 9)
Culture Mandala : The Bulletin of the Centre for East-West Cultural and Economic Studies     Open Access  
Décalages : An Althusser Studies Journal     Open Access  
Decolonization : Indigeneity, Education & Society     Open Access   (Followers: 8)
Defence Studies     Hybrid Journal   (Followers: 22)
Defense & Security Analysis     Hybrid Journal   (Followers: 19)
Democracy & Education     Open Access   (Followers: 14)
Democratic Communiqué     Open Access   (Followers: 1)
Democratic Theory     Full-text available via subscription   (Followers: 7)
Democratization     Hybrid Journal   (Followers: 32)
Democrazia e diritto     Full-text available via subscription   (Followers: 2)
Demokratie und Geschichte     Hybrid Journal  
Demokratizatsiya: The Journal of Post-Soviet Democratization     Full-text available via subscription   (Followers: 8)
Der Donauraum     Hybrid Journal  
Der Staat     Full-text available via subscription   (Followers: 13)
Desafíos     Open Access  
Development and Change     Hybrid Journal   (Followers: 47)
Digest of Middle East Studies     Hybrid Journal   (Followers: 11)
Diplomacy & Statecraft     Hybrid Journal   (Followers: 10)
Diplomatic History     Hybrid Journal   (Followers: 19)
Diritto, immigrazione e cittadinanza     Open Access   (Followers: 4)
Dissent     Full-text available via subscription   (Followers: 8)
Diversité urbaine     Full-text available via subscription   (Followers: 1)
Dynamics of Asymmetric Conflict: Pathways toward terrorism and genocide     Hybrid Journal   (Followers: 13)
East European Jewish Affairs     Hybrid Journal   (Followers: 13)
East European Politics     Hybrid Journal   (Followers: 10)
Economia Politica     Hybrid Journal   (Followers: 36)
Ecopolítica     Open Access  
eJournal of eDemocracy and Open Government     Open Access   (Followers: 8)
El Cotidiano     Open Access   (Followers: 1)
Electoral Studies     Hybrid Journal   (Followers: 28)
Em Pauta : Teoria Social e Realidade Contemporânea     Open Access  
Encuentro     Open Access  
Environmental Politics     Hybrid Journal   (Followers: 14)
Equal Opportunities International     Hybrid Journal   (Followers: 3)
Espacios Públicos     Open Access  
Estudios Políticos     Open Access  
Estudios Políticos     Open Access  
Estudos Avançados     Open Access  
Ethical Theory and Moral Practice     Hybrid Journal   (Followers: 18)
Ethics & Global Politics     Open Access   (Followers: 7)
Ethics in Science and Environmental Politics     Hybrid Journal  
Éthique publique     Open Access  
Études internationales     Full-text available via subscription   (Followers: 1)
Eureka Street     Full-text available via subscription   (Followers: 4)
Europe's World     Open Access   (Followers: 1)
European Integration Studies     Open Access   (Followers: 12)
European Journal of American Culture     Hybrid Journal   (Followers: 2)
European Journal of Government and Economics     Open Access   (Followers: 6)
European Journal of International Relations     Hybrid Journal   (Followers: 52)
European Journal of Political Economy     Hybrid Journal   (Followers: 43)
European Journal of Political Research     Hybrid Journal   (Followers: 68)

        1 2 3 4 | Last

Journal Cover Digest of Middle East Studies
  [11 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1060-4367 - ISSN (Online) 1949-3606
   Published by John Wiley and Sons Homepage  [1579 journals]
  • The Rise and Demise of the Middle East Quest for Reforms, 2011–2017
    • Authors: Mohammed M. Aman
      Abstract: Six years have passed since Arab masses in Tunisia, Egypt, Libya, Syria, Bahrain, and Yemen revolted against oppressive, corrupt, and autocratic regimes. These and lesser revolts in Morocco and Jordan — as well as muted ones in the oil producing Gulf States — shared common goals and themes: justice, dignity, economic, political, and social reforms (el-Gingihy, ). The revolutionaries wanted to end government bloating and oppressive bureaucracies; and political and massive public corruption by the ruling classes; and instead, involve citizens in the participation in governance and policymaking. The oil-rich countries were quick to shower their nationals with salary bonuses and more generous subsidies. The poorer Arab countries were quick to unleash their violent security forces on the masses in order to quell the uprisings using brute military force, including using poison gas in Syria, and operating mass killings of demonstrators at Rab‘a Square in Cairo, Egypt. With the exception of Tunisia, the rest of the Arab countries reverted to oppressive regimes, or civil war chaos, as was the case in Libya and Yemen. The United States, which hailed the Arab uprisings during the reign of the Obama Administration, has changed course under the isolationist Trump Administration, which looks upon all Arabs and Muslim people and nations as potential supporters of what the current administration labels as Muslim terrorism. Along with an analysis of events in the region, this article also reviews the most recent books published which deal with the Arab revolts, and which include what lies ahead for the Arab world under the new rulers who replaced old regimes. It will also analyze the Arab countries’ response to a Trump Administration that seems to adopt political isolationism, while at the same time, showing an obvious inclination for personal and national business involvement in the region, such as the recent opening of a Trump golf course in the United Arab Emirates, and the appointment of former MOBIL CEO Executive Rex Tillerson, who has strong business ties with Russia and the oil-producing Gulf States.
      PubDate: 2017-04-25T20:50:27.124681-05:
      DOI: 10.1111/dome.12107
       
  • Issue Information
    • Abstract: No abstract is available for this article.
      PubDate: 2017-04-24T05:05:17.592835-05:
      DOI: 10.1002/eco.1783
       
  • Israel: Divided by Religion and Education
    • Authors: Judith A. Cochran
      Abstract: Israel is a democracy splintered by religion and education. Two of its fastest growing religious groups, ultra-Orthodox and Muslim Israeli Arabs, are not learning democratic principles or marketable skills that enable them to assist in the economic development of the country. Even Israelis who are attending secular and religious Israeli government schools are academically behind in mathematics as measured on 2011 international achievement tests of PISA and TIMSS. The history of religion and education from 1928 to 1955 built the foundation for the current divisions. The impact of the Ottoman and British occupation on citizens is particularized thorough the experiences of Elias Tuma, who lived under British and Israeli government systems. Today's educational system in Israel reinforces religious and sectarian conflict among its citizens. Educational and religious structural suggestions are provided for readers to consider. The implications of this work for future research are provided.
      PubDate: 2017-04-18T05:20:43.733742-05:
      DOI: 10.1111/dome.12106
       
  • 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
       
  • 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
       
  • 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
       
  • The Perpetuation of Regime Security in Gulf Cooperation Council States: A
           Multi-Lens Approach
    • Authors: M. Evren Tok; Jason J. McSparren, Michael Olender
      Abstract: Gulf Cooperation Council (GCC) states have been engaging in diversification efforts, yet the types of efforts suggest that the primary interest is regime security. Regional foreign policy is complex; hence we propose a multi-lens approach to analyze overlapping and complementary political, economic, and social forces. The international political economy of hydrocarbons demonstrates the similarities among GCC states, regional dynamics illustrate interstate relations and similar patterns, while economic diversification suggests individual state trajectories and comparative and competitive patterns. By outlining the contemporary context for GCC states, we argue that low oil prices, regional dependence on hydrocarbons, and trends in economic diversification efforts signal GCC states' preference to reinforce their rentier systems with alternative state revenue streams. GCC states' diversification into new markets and sectors and use of state-owned enterprises in microcompetitions indicate a new search for alternative revenue streams and prestige, which in turn are used to assure the perpetuation of regime security. This finding sets trajectories and implications for the region, specifically economic stagnation and supplementary diversification processes.
      PubDate: 2017-03-15T03:25:41.522114-05:
      DOI: 10.1111/dome.12105
       
  • 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
       
  • 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
       
  • 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
       
  • Exploring the Phenomena of Online Dating Platforms Versus Saudi
           Traditional Spouse Courtship in the 21st Century
    • Authors: Ayman Naji Bajnaid; Tariq Elyas
      Abstract: While traditional Saudi Arabian courtship is rigidly structured according to a set of Islamic codes of conduct, over the past decade, Saudis have increasingly turned to unconventional means of finding and courting a potential spouse: matrimonial Web sites. This research explores the debate in the literature on computer meditated communication regarding whether online settings provide rich information about other users, as they show that online interactions can provide more information about the opposite sex for users who belong to gender-segregated societies than they can get through their offline lives. The article will shed some light on the interplay between young generations and their obsessions with the world of Internet dating and the societal norms and social conducts with which they are comfortable while living in Saudi Arabia. The article may contribute to the online dating literature by showing the similarities and differences between conservative, Islamic Saudi users and Western users when using Web sites to search for a potential mate. The research shows the power of both social and religious norms in affecting these users’ behaviors and decisions when using matrimonial Web sites.
      PubDate: 2017-02-22T02:45:48.711605-05:
      DOI: 10.1111/dome.12104
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • Exploring Collaborative Civic Leadership Among Young Tunisians: Inviting
           Despair, Creating Hope
    • Authors: Sarah McLewin Kincaid
      Abstract: This article explores how civically engaged youth in Tunisia are approaching collaboration with noncivically engaged youth to promote greater levels of civic participation. This article is based on qualitative research conducted in Tunis, Tunisia during the summer of 2015 with 16 youth, all under the age of 35. This article will explore youth attitudes regarding civic engagement and barriers to participation in postauthoritarian Tunisia. This article also explores how civically engaged youth utilize informal social spaces such as coffee shops, universities, and social media sites to stir a sense of hope and pride in activism. This research provides a rich snapshot of civically and noncivically engaged youth who comprise 51% of Tunisia's population and led the 2011 revolution that burgeoned the so-called Arab Spring in North Africa and the Middle East. These findings bring into question labels such as “politically inactive” and “potential ISIS fighters” that are employed in the dominant narrative on Tunisian youth. Finally, this research suggests that Tunisian youth wield powerful leadership skills that will continue to play a critical role in the transformation of civic and social norms.
      PubDate: 2017-01-10T22:40:21.482051-05:
      DOI: 10.1111/dome.12102
       
  • 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
       
 
 
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