pinecone/core-2020-05-10-deduplication huggingface dataset:
Macroinvertebrate responses to flow and stream temperature variability across regulated and non-regulated rivers

This is an Open Access Article. It is published by Wiley under the Creative Commons Attribution 4.0 International Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/Flow regulation via impoundments threatens lotic ecosystems and the services they provide globally. Impoundments drastically alter flow and stream temperature variability within fluvial environments, but efforts to quantify ecohydrological and ecothermal responses to flow regulation in conjunction have been sparsely explored to date. This study examined macroinvertebrate community responses to river flow (discharge) and stream temperature variability across paired regulated and non-regulated systems associated with three reservoirs located in adjacent catchments. Community abundances, functional traits and biomonitoring indices were examined and ecological differences between non-regulated and regulated sites were quantified, with the most sensitive faunal response being correlated against a suite of flow and thermal indices. Regulated sites exhibited reduced low-flow variability and rapid increases in discharge during peak flows that regularly exceeded those conveyed by non-regulated sites, whilst stream temperature variability was highly congruent between sites. Macroinvertebrate functional traits were particularly sensitive to flow regulation and incorporating biomonitoring indices marginally improved the ecological discrimination between regulated and non-regulated sites. Unlike community abundances, functional traits did not vary spatially between catchments, highlighting that such information could guide the implementation of regionally uniform environmental flows. Macroinvertebrate communities responded significantly to various hydrological parameters, particularly those associated with the timing of extreme flows, but were less sensitive to thermal controls. Future research should explore ecological responses to antecedent hydrological and stream temperature variability associated with flow regulation to provide a better understanding of the underlying mechanisms driving biotic alterations, which could guide future environmental flow methodologies
Responses of fish and invertebrates to floods and droughts in Europe

Floods and droughts, two opposite natural components of streamflow regimes, are known to regulate population size and species diversity. Quantifiable measures of these disturbances and their subsequent ecological responses are needed to synthesize the knowledge on flow–ecosystem relationships. This study for the first time combines the systematic review approach used to collect evidence on the ecological responses to floods and droughts in Europe with the statistical methods used to quantify the extreme events severity. Out of 854 publications identified in literature search, 54 papers were retained after screening and eligibility checks, providing in total 82 case studies with unique extreme event—ecological response associations for which data were extracted. In this way, a database with metadata of case studies that can be explored with respect to various factors was constructed. This study pinpointed the research gaps where little evidence could be synthesized, for example, drought event studies and fish studies. It was demonstrated that in many cases the studied metrics (abundance, density, richness, and diversity) showed statistically significant decreases after or during the event occurrence. The responses in invertebrate density and richness were in general more negative than the corresponding responses in fish. Biota resistance to floods was found to be lower than the resistance to droughts. The severity of extreme events was not found to be an important factor influencing ecological metrics, although this analysis was often hampered by insufficient number of case studies. Conceivably, other factors could mask any existing relationships between disturbance severity and biotic response
Projecting impacts of climate change on habitat availability in a macrophyte dominated chalk river

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
Does shell shape variation play a role in conservation of the long‐lived freshwater bivalve Diplodon chilensis (Bivalvia, Hyriidae)?

Freshwater bivalves of the order Unionoida display an uncommon phenotypic plasticity with high interpopulation and intrapopulation morphological variability, which could be advantageous for coping with habitat modifications. However, unionoids have suffered a marked population decline in different parts of the world in the last decades. A decline in some populations of the South American long‐lived freshwater mussel Diplodon chilensis as a consequence of habitat deterioration has recently been recorded. Ontogenetic allometry and shape variation in shells of D. chilensis from 2 different sites, Paimun lake and Chimehuin river, North Patagonia, Argentina, have been studied. For these purposes, geometric morphometric methods were used. Shell shape shows differences between sites, which the shells from Chimehuin river show less intrapopulation variability; are more elongated, with the anterior part extended upwards and the posterior part downwards; and show a steeper anterior curvature at the umbo compared to those from Paimún lake. These characteristics make shell shape more streamlined to withstand river current. Furthermore, the extended posterior‐ventral part in river shells coincides with higher foot weight that would improve anchoring to the river rocky–sandy substrate. River shells present a bounded eco‐morphotype whereas the higher variability of lake shells includes the “river eco‐morphotype.” Growth is allometric throughout life in both sites and is not sex‐dependent. The success of river repopulation programmes using mussels from lake populations may be increased by transplanting selected individuals that show “river eco‐morphotype.
Life‐cycle responses of a Mediterranean non‐migratory cyprinid species, the Northern Iberian chub (Squalius carolitertii Doadrio, 1988), to streamflow regulation.

Streamflow is considered a driver of interspecific and intraspecific life‐history differences among freshwater fish. Therefore, dams and related flow regulation can have deleterious impacts on their life cycles. The main objective of this study was to assess existing differences in the growth and reproduction patterns of a non‐migratory fish species (the Northern Iberian chub, Squalius carolitertii, Doadrio, 1988), between nonregulated and regulated watercourses. For 1 year, samples were collected from two populations of Iberian chub, inhabiting rivers with nonregulated and regulated flow regimes. Flow regulation for water storage promoted changes in chub's condition, duration of spawning, fecundity, and oocyte size. However, this non‐migratory species was less responsive to streamflow regulation than other native potamodromous species. Findings from this study are important to understand changes imposed by regulated rivers and can be used to support the implementation of suitable river management practices
Extreme flow variability and the 'boom and bust' ecology of fish in arid-zone floodplain rivers: a case history with implications for environmental flows, conservation and management

Floodplain rivers in arid and semi-arid regions may be the most threatened of all river systems because water resource developments typically dampen their most distinctive characteristics-extreme flow variability and 'boom and bust' ecological dynamics. This article shows how one of the world's most variable arid-zone river systems-Cooper Creek in Australia's Lake Eyre Basin-functions and how it supports its unique fish assemblage and productive fisheries. The ecological roles of drought refugia, channel flows and flooding are reviewed in relation to fish persistence and losses, life history strategies, movement potential, food web processes and production levels. Comparisons are drawn with other floodplain rivers and fisheries to draw out common understandings and universal principles for conservation and management of arid-zone rivers and their fish resources. Ecological implications of hydrologic alterations and land-based activities are presented to highlight the importance of maintaining the hydrologic, geomorphic, sedimentary and biogeochemical processes of arid-zone river systems. Preservation or restoration of natural flow intermittency, sequential flood pulses, complex habitat mosaics, connectivity and identification of the environmental flow requirements for highly valued species and processes are key scientific principles for the management of arid-zone floodplain rivers.Griffith Sciences, Griffith School of EnvironmentFull Tex
Understanding ecohydrological connectivity in savannas: a system dynamics modelling approach

To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work.\ud
The published article is copyrighted by John Wiley & Sons, Ltd. and can be found at: http:http://www.wiley.com/WileyCDA/Ecohydrological connectivity is a system level property that results from the linkages in the networks of water transport through ecosystems, by which feedbacks and other emergent system behaviours may be generated. We created a system dynamics model that represents primary ecohydrological networks to examine how connectivity between ecosystem components impacts ecosystem processes. Here, we focused on the savanna ecosystems, although the analyses may be expanded to other ecosystem types in the future. To create the model, a set of differential equations representing ecohydrological processes was programmed into the dynamic solver Vensim. Stocks of water storage (e.g. atmospheric and soil moisture) were linked by flows [e.g. precipitation and evapotranspiration (ET)] that were in turn dynamically controlled by the amount of water stored. Precipitation was forced stochastically, and soil moisture and potential ET controlled actual ET. The model produced extended, probabilistic time series of stocks and flows, including precipitation, soil moisture, runoff, transpiration, and groundwater recharge. It was used to describe the behaviour of several previously studied savanna ecosystems in North America and Africa. The model successfully reproduced seasonal patterns of soil moisture dynamics and ET at the California site. It also demonstrated more complex, system level behaviours, such as multiyear persistence of drought and synergistic or antagonistic responses to disconnection of system components. Future improvements to the model will focus on capturing other important aspects of long-term system behaviour, such as changes in physiology or phenology, and spatial heterogeneity, such as the patchwork nature of savannas. Copyright (C) 2011 John Wiley & Sons, Ltd
A framework for hydrologic classification with a review of methodologies and applications in ecohydrology

Hydrologic classification is one of the most widely applied tasks in ecohydrology. During the last two decades, a considerable effort has gone into analysis and development of methodological approaches to hydrologic classification. We reviewed the process of hydrologic classification, differentiating between an approach based on deductive reasoning using environmental regionalization, hydrologic regionalization and environmental classification whereby environmental variables assumed to be key determinants of hydrology are analysed and one based on inductive reasoning using streamflow classification whereby hydrologic data are analysed directly. We explored past applications in ecohydrology, highlighting the utility of classifications in the extrapolation of hydrologic information across sparsely gauged landscapes, the description of spatial patterns in hydrologic variability, aiding water resource management, and in the identification and prioritization of conservation areas. We introduce an overarching methodological framework that depicts critical components of the classification process and summarize important advantages and disadvantages of commonly used statistical approaches to characterize and predict hydrologic classes. Our hope is that researchers and managers will be better informed when having to make decisions regarding the selection and proper implementation of methods for hydrologic classification in the future.Full Tex
A conceptual framework for understanding semi-arid land degradation: ecohydrological interactions across multiple-space and time scales

publication-status: Publishedtypes: ArticleCopyright © 2008 John Wiley & Sons, Ltd. This is the author's post-print version of an article published in Ecohydrology, 2008, Vol. 1, Issue 1, pp. 23 - 34. The definitive version is available at www3.interscience.wiley.comLand degradation is a problem prolific across semi-arid areas worldwide. Despite being a complex process including both biotic and abiotic elements, previous attempts to understand ecosystem dynamics have largely been carried out within disparate disciplines of ecology and hydrology, which has led to significant limitations. Here, an ecohydrological framework is outlined. to provide a new direction for the study of land degradation in semi-arid ecosystem. Unlike other frameworks that draw upon hierarchy theory to provide a board, non-explicit conceptual framework is based upon the explicit linkage of process operating over the continuum of temporal and spatial scales by perceiving the ecosystem as a series of structural and functional connections, within which interactions between biotic and abiotic components of the landscape occur. It is hypothesized that semi-arid land degradation conforms to a cusp-catastrophe model in which the two controlling variables are abiotic structural connectivity and abiotic functional connectivity, which implicitly account for ecosystem resilience, and biotic structural and function connectivity. It is suggest therefore that future research must (1) evaluate how abiotic and biotic function (i.e. water, sediment and nutrient loss/redistribution) vary over grass-shrub transitions and (2) quantify the biotic/abiotic structure over grass-shrub transitions, to (3) determine the interactions between ecosystem structure and function. and interaction/feedbacks between biotic and abiotic components of the ecosystem. Copyright (C) 2008 John Wiley & Sons, Ltd
Circumpolar habitat use in the southern elephant seal: implications for foraging success and population trajectories

In the Southern Ocean, wide-ranging predators offer the opportunity to quantify how animals respond to differences in the environment because their behavior and population trends are an integrated signal of prevailing conditions within multiple marine habitats. Southern elephant seals in particular, can provide useful insights due to their circumpolar distribution, their long and distant migrations and their performance of extended bouts of deep diving. Furthermore, across their range, elephant seal populations have very different population trends. In this study, we present a data set from the International Polar Year project; Marine Mammals Exploring the Oceans Pole to Pole for southern elephant seals, in which a large number of instruments (N = 287) deployed on animals, encompassing a broad circum-Antarctic geographic extent, collected in situ ocean data and at-sea foraging metrics that explicitly link foraging behavior and habitat structure in time and space. Broadly speaking, the seals foraged in two habitats, the relatively shallow waters of the Antarctic continental shelf and the Kerguelen Plateau and deep open water regions. Animals of both sexes were more likely to exhibit area-restricted search (ARS) behavior rather than transit in shelf habitats. While Antarctic shelf waters can be regarded as prime habitat for both sexes, female seals tend to move northwards with the advance of sea ice in the late autumn or early winter. The water masses used by the seals also influenced their behavioral mode, with female ARS behavior being most likely in modified Circumpolar Deepwater or northerly Modified Shelf Water, both of which tend to be associated with the outer reaches of the Antarctic Continental Shelf. The combined effects of (1) the differing habitat quality, (2) differing responses to encroaching ice as the winter progresses among colonies, (3) differing distances between breeding and haul-out sites and high quality habitats, and (4) differing long-term regional trends in sea ice extent can explain the differing population trends observed among elephant seal colonies.Publisher PDFPeer reviewe
Circumpolar habitat use in the southern elephant seal : implications for foraging success and population trajectories

In the Southern Ocean, wide-ranging
predators offer the opportunity to quantify how animals
respond to differences in the environment because their behavior and population trends are an integrated
signal of prevailing conditions within multiple marine habitats. Southern elephant seals in particular, can
provide useful insights due to their circumpolar distribution, their long and distant migrations and their
performance of extended bouts of deep diving. Furthermore, across their range, elephant seal populations
have very different population trends. In this study, we present a data set from the International Polar Year
project; Marine Mammals Exploring the Oceans Pole to Pole for southern elephant seals, in which a large
number of instruments (N = 287) deployed on animals, encompassing a broad circum-Antarctic
geographic
extent, collected in situ ocean data and at-sea
foraging metrics that explicitly link foraging behavior
and habitat structure in time and space. Broadly speaking, the seals foraged in two habitats, the relatively
shallow waters of the Antarctic continental shelf and the Kerguelen Plateau and deep open water regions.
Animals of both sexes were more likely to exhibit area-restricted
search (ARS) behavior rather than transit
in shelf habitats. While Antarctic shelf waters can be regarded as prime habitat for both sexes, female seals
tend to move northwards with the advance of sea ice in the late autumn or early winter. The water masses
used by the seals also influenced their behavioral mode, with female ARS behavior being most likely in
modified Circumpolar Deepwater or northerly Modified Shelf Water, both of which tend to be associated
with the outer reaches of the Antarctic Continental Shelf. The combined effects of (1) the differing habitat
quality, (2) differing responses to encroaching ice as the winter progresses among colonies, (3) differing
distances between breeding and haul-out
sites and high quality habitats, and (4) differing long-term
regional
trends in sea ice extent can explain the differing population trends observed among elephant seal
colonies.http://www.esajournals.org/loi/ecsphb2017Mammal Research InstituteZoology and Entomolog
Faster acquisition of symbiotic partner by common mycorrhizal networks in early plant life stage

Arbuscular mycorrhizal (AM) fungi usually improve plant performance yet our knowledge\ud
about their effects on seed germination and early plant establishment is very limited. We\ud
performed a factorial greenhouse experiment where the seeds from four low Arctic cooccurring\ud
mycorrhizal herbs (Antennaria dioica, Campanula rotundifolia, Sibbaldia\ud
procumbens, and Solidago virgaurea) were germinated alone or in the vicinity of an adult\ud
Sibbaldia plant with or without AM fungi; given either as spores or being present in a\ud
common mycorrhizal network (CMN). Three different AM fungal species were examined to\ud
assess species-specific differences in symbiont acquisition rate. Out of the four plant species\ud
investigated, the presence of AM fungi affected seed germination only in Campanula and this\ud
effect was dependent on whether the AM fungi were present in the soil as spores or as a\ud
CMN. Overall, after germination, developing seedlings showed AM fungal colonization in\ud
their roots as soon as 2 days after cotyledon emergence. Our results show that CMN may\ud
provide germinating seedlings faster acquisition of the AM fungal partner in comparison to\ud
acquisition from spores. Furthermore, there were AM species-specific differences in the\ud
symbiont acquisition rate highlighting the importance of species identity in AM interactions.\ud
These findings suggest that while AM fungi may not play a fundamental role during seed\ud
germination, plant community composition may be affected by the species-specific AM\ud
fungal effects on seedling establishment and CMN acquisition