Fish community responses to global changes in French streams: patterns and mechanisms

Lucie Kuczynski (1), Pierre Legendre (2) , Gaël Grenouillet (3)

1  UMR5174 EDB (Laboratoire Evolution et Diversité Biologique),  CNRS, UPS, ENFA, 118 route de Narbonne, F-31062, Toulouse, France, UPS, UMR5174 EDB, Université de Toulouse 3, F-31062, Toulouse, France, lucie.kuczynski@univ-tlse3.fr

2  Département de sciences biologiques, Université de Montreal, C.P. 6128, succursale Centre-ville, Montreal, QC, H3C 3J7, Canada, pierre.legendre@umontreal.ca

3  UMR5174 EDB (Laboratoire Evolution et Diversité Biologique),  CNRS, UPS, ENFA, 118 route de Narbonne, F-31062, Toulouse, France, UPS, UMR5174 EDB, Université de Toulouse 3, F-31062, Toulouse, France, gael.grenouillet@univ-tlse3.fr

Species’ distribution shifts in response to climate change have been documented for many taxa, and these shifts can result in community reorganization which can have considerable impacts on species interactions and lead to profound alterations of ecosystem functioning. However, there is ample evidence of idiosyncratic responses, which limits our ability to predict the consequences of range shifts at the community level. Thus, it is critical to evaluate how species assemblages are responding to on-going environmental changes, and to assess biodiversity changes from both a spatial  and  temporal  perspective  to  understand  underlying  processes.  Based  on  national monitoring data collected over the last decades in France, here we explore temporal changes in alpha and beta diversity of stream fish communities by comparing  more than 300 resurveyed communities between an initial (1980 – 1993) and a contemporary period  (2004 – 2012). We quantified for each community how its composition and its uniqueness have changed over time relative to the overall temporal change that other communities experienced. Finally, we identified the environmental drivers of these temporal biodiversity  changes.  Overall, we found a global homogenization  of  freshwater  fish  communities  since  the  80s.  Our  results  showed  that  the changes in community structure were spatially structured dependent but mainly due to species losses. Finally, we demonstrated that these temporal changes were mainly driven by changes in rainfall, temperature  seasonality and  the relative abundance  of non-native species  over time, pointing to the importance of understanding the complex interplay of multiple environmental and biotic drivers in defining future patterns of freshwater biodiversity.

Species on the Move

An International Conference Series

The conference brings together scientists and natural resource managers working in the disciplines of global change, biogeography and evolution, and relevant in contexts of natural resource management, biodiversity management and conservation, and theoretical ecology.


Species responses to climate change is a rapidly evolving research field, however, much of our progress is being made in independent research areas: e.g. understanding the process vs responding to the implications, terrestrial vs marine ecosystems, global meta-analyses vs in depth species-specific approaches. This interdisciplinary conference develops connections between these parallel streams, and across temporal and spatial scales.

Conference Managers

Please contact the team at Conference Design with any questions regarding the conference.
© 2015 - 2019 Conference Design Pty Ltd