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Nested patterns of spatial diversity revealed for fish assemblages in a west European river
Author(s) -
Ibarra A. A.,
Park Y.S.,
Brosse S.,
Reyjol Y.,
Lim P.,
Lek S.
Publication year - 2005
Publication title -
ecology of freshwater fish
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 55
eISSN - 1600-0633
pISSN - 0906-6691
DOI - 10.1111/j.1600-0633.2005.00096.x
Subject(s) - ecology , fish <actinopterygii> , spatial ecology , geography , ecological succession , drainage basin , streams , sampling (signal processing) , fishery , biology , cartography , computer network , filter (signal processing) , computer science , computer vision
– The longitudinal distribution of fish assemblages across a large west European river basin, the Garonne river (south‐west France) were investigated using a self‐organising map. This nonlinear statistical method was employed to classify sampling sites according to their species composition. We found three main nested patterns in an aggregated hierarchy: a replacement and succession of species along a gradient without defined boundaries, four main zones of fish assemblages and an upstream‐downstream shift of fish communities. We suggest that fish assemblages are too complex to be identified with a single species as in the zonation model, and that the diversity patterns found might be part of the same ecological process influencing fish assemblages on different spatial scales. Thus, discrepancies in the analysis of longitudinal patterns of fish communities in streams may have been basically a matter of local conditions and of conceptual perception.