Journal Article

A global perspective on the functional responses of stream communities to flow intermittence

Westfälische Wilhelms-Universität Münster = University of Münster = Université de Münster [Münster, Allemagne] (WWU), Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC) ; Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Crabot, Julie, Meyer, Elisabeth, I, Mondy, Cedric, P, Fritz, Ken, M, Wood, Paul, J, Bogan, Michael, T, Oregon State University (OSU), Loughborough University, Office français de la biodiversité (OFB), RiverLy - Fonctionnement des hydrosystèmes (RiverLy) ; Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Greenwood, Michelle, J, Usseglio‐polatera, Philippe, United States Environmental Protection Agency [Cincinnati], Datry, T, National Institute of Water and Atmospheric Research [Christchurch] (NIWA), Laboratoire de Géographie Physique et Environnementale (GEOLAB) ; Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut Sciences de l'Homme et de la

2021

Overview

The current erosion of biodiversity is a major concern that threatens the ecological integrity of ecosystems and the ecosystem services they provide. Due to global change, an increasing proportion of river networks are drying and changes from perennial to non-perennial flow regimes represent dramatic ecological shifts with potentially irreversible alterations of community and ecosystem dynamics. However, there is minimal understanding of how biological communities respond functionally to drying. Here, we highlight the taxonomic and functional responses of aquatic macroinvertebrate communities to flow intermittence across river networks from three continents, to test predictions from underlying trait-based conceptual theory. We found a significant breakpoint in the relationship between taxonomic and functional richness, indicating higher functional redundancy at sites with flow intermittence higher than 28%. Multiple strands of evidence, including patterns of alpha and beta diversity and functional group membership, indicated that functional redundancy did not compensate for biodiversity loss associated with increasing intermittence, contrary to received wisdom. A specific set of functional trait modalities, including small body size, short life span and high fecundity, were selected with increasing flow intermittence. These results demonstrate the functional responses of river communities to drying and suggest that ongoing biodiversity reduction due to global change in drying river networks is threatening their functional integrity. These results indicate that such patterns might be common in these ecosystems, even where drying is considered a predictable disturbance. This highlights the need for the conservation of natural drying regimes of intermittent rivers to secure their ecological integrity.

• Publisher: Wiley,CCSD,Blackwell Publishing Ltd,John Wiley & Sons, Inc
• Subject: Biodiversity / Biodiversity loss / Body size / Drying / Ecology / Ecosystem dynamics / Ecosystem integrity / Ecosystem services / ecosystems / Environmental Sciences / Fecundity / Flow / fragmentation / Functional groups / global change / Integrity / Life span / life-history traits / longevity / Macroinvertebrates / Networks / Redundancy / River networks / Rivers / species diversity / streams / Taxonomy / temporary rivers
• ISBN: 0006955519000