Long-term trends in trait structure of riverine communities facing predation risk increase and trophic resource decline.

Autor: Latli A; Research Unit in Environmental and Evolutionary Ecology, University of Namur, rue de Bruxelles 61, B-5000, Namur, Belgium., Descy JP; Research Unit in Environmental and Evolutionary Ecology, University of Namur, rue de Bruxelles 61, B-5000, Namur, Belgium., Mondy CP; Biodiversity and Plasticity in Hydrosystems, CNRS UMR 5023 LEHNA, University Lyon 1, Bât Forel, 69622, Villeurbanne Cedex, France., Floury M; Aquatic Environments, Ecology and Pollution, UR MALY, Irstea, 5 rue de la Doua, 70077, 69626, Villeurbanne, France., Viroux L; Research Unit in Environmental and Evolutionary Ecology, University of Namur, rue de Bruxelles 61, B-5000, Namur, Belgium., Otjacques W; Research Unit in Environmental and Evolutionary Ecology, University of Namur, rue de Bruxelles 61, B-5000, Namur, Belgium., Marescaux J; Research Unit in Environmental and Evolutionary Ecology, University of Namur, rue de Bruxelles 61, B-5000, Namur, Belgium., Depiereux E; Research Unit in Environmental and Evolutionary Ecology, University of Namur, rue de Bruxelles 61, B-5000, Namur, Belgium., Ovidio M; Laboratory of Fish Demography and Hydroecology, University of Liège, Belgium., Usseglio-Polatera P; Interdisciplinary Laboratory for Continental Environments, CNRS UMR 7360 LIEC, University of Lorraine, Campus Bridoux, 57070, Metz, France., Kestemont P; Research Unit in Environmental and Evolutionary Ecology, University of Namur, rue de Bruxelles 61, B-5000, Namur, Belgium.
Jazyk: angličtina
Zdroj: Ecological applications : a publication of the Ecological Society of America [Ecol Appl] 2017 Dec; Vol. 27 (8), pp. 2458-2474. Date of Electronic Publication: 2017 Nov 29.
DOI: 10.1002/eap.1621
Abstrakt: Many large European rivers have undergone multiple pressures that have strongly impaired ecosystem functioning at different spatial and temporal scales. Global warming and other environmental changes have favored the success of invasive species, deeply modifying the structure of aquatic communities in large rivers. Some exogenous species could alter trophic interactions within assemblages by increasing the predation risk for potential prey species (top-down effect) and limiting the dynamics of others via resource availability limitation (bottom-up effect). Furthermore, large transboundary rivers are complex aquatic ecosystems that have often been poorly investigated so that data for assessing long-term ecological trends are missing. In this study, we propose an original approach for investigating long-term combined effects of global warming, trophic resource decrease, predation risk, and water quality variations on the trait-based structure of macroinvertebrate and fish assemblages over 26 yr (1985-2011) and 427-km stretch of the river Meuse (France and Belgium). The study of temporal variations in biological, physiological, and ecological traits of macroinvertebrate and fish allowed identifying community trends and distinguishing impacts of environmental perturbations from those induced by biological alterations. We provide evidence, for this large European river, of an increase in water temperature (close to 1°C) and a decrease in phytoplankton biomass (-85%), as well as independent effects of these changes on both invertebrate and fish communities. The reduction of trophic resources in the water column by invasive molluscs has dramatically affected the density of omnivorous fish in favor of invertebrate feeders, while scrapers became the major feeding guild among invertebrates. Macroinvertebrate and fish communities have shifted from large-sized organisms with low fecundity to prolific, small-sized organisms, with early maturity, as a response to increased predation pressure.
(© 2017 by the Ecological Society of America.)
Databáze: MEDLINE
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