BIODIVERSITY AND FOODWEB COMPLEXITY IN REGULATED AQUATIC ECOSYSTEMS
Effects of river impoundment on fish community: A global meta-analysis
By using meta-analyses, we examined the effects of impoundment on fish biodiversity (richness, diversity and evenness) and species assemblage’s metrics (number of alien species, trophic level position and macrohabitat guild), and asked if fish communities in impounded ecosystems are affected similarly across three large biomes (boreal, temperate and tropical; Turgeon et al. 2019).
Take home messages
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Implications
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Effects of boreal river impoundment on fish community: a multi-scale approach
We used a multi-scale approach to examine changes in littoral fish communities in reservoirs over 20 years, using a network of sites in northern Québec (Canada) with minimal confounding pressures. We examined changes in diversity over time using α- and δ-diversity (extrapolated richness, H’ Diversity and J’ Evenness) and β-diversity (species turnover rate) metrics, and we also investigated change in species assemblages using multivariate analyses (Turgeon et al. 2018).
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Developing biodiversity indicators of the impacts of reservoirs in LCA
We used direct empirical data of change in fish species richness following impoundment to develop ecological indicators to be used in the Life Cycle Assessment (LCA) and accounting for hydropower impacts on aquatic ecosystems (Turgeon et al. 2021).
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We used the National Lake Assessment (NLA; 148 reservoirs) and the National Rivers and Streams Assessment (NRSA; 2121 rivers and streams) of the United States Environmental Protection Agency (USEPA) to develop LCA indicators evaluating the impacts of impoundment on macroinvertebrate biodiversity at three scales (Trottier et al. 2021).
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*NEW OFFER* QUANTIFYING MULTITROPHIC BIODIVERSITY IN AQUATIC ECOSYSTEMS OVER TIME AND SPACE
There is accumulating evidence of losses in richness in regulated aquatic ecosystems but considering alternative metrics of biodiversity such as functional diversity or multitrophic biodiversity is now at the fore in Biodiversity-Ecosystem Functions research (B-EF). A multitrophic biodiversity approach, combining horizontal diversity (i.e., species richness within trophic levels or groups) and vertical diversity (i.e., the number of trophic levels or food chain length), can identify nuanced changes in the way species interact and co-exist. I've got funding to examine if multitrophic biodiversity is simplified in regulated ecosystems compared to natural ecosystems over time and space by capitalizing on recent developments in ecological network.
See offer for a fully funded PhD! This could be your project! Cool field work in perspective. |
*NEW OFFER* COMPLEXITY, CONFIGURATION, AND STABILITY OF FOOD WEB NETWORKS IN AQUATIC ECOSYSTEMS
Recent data exploration suggests a prevalence of inverted trophic pyramids (ITPs) in some boreal reservoirs in Canada. This configuration could be unstable. I got funding to characterize and describe the configuration of Quebec's food web aquatic regulated ecosystems over time (reservoirs of different age) and space and to compare them with natural ecosystems.
See offer for a fully funded PhD! This could be your project! Cool field work in perspective. |