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Spatial patterns and determinants of trait dispersion in freshwater fish assemblages across Europe
Author(s) -
Côte Jessica,
Kuczynski Lucie,
Grenouillet Gaël
Publication year - 2019
Publication title -
global ecology and biogeography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.164
H-Index - 152
eISSN - 1466-8238
pISSN - 1466-822X
DOI - 10.1111/geb.12896
Subject(s) - trait , ecology , spatial ecology , dispersion (optics) , biology , niche , spatial variability , ecological niche , overdispersion , taxon , geography , environmental science , habitat , statistics , population , demography , physics , mathematics , computer science , optics , programming language , poisson regression , sociology
Aim Understanding how species assemble into assemblages and identifying the determinants of assembly processes remains a key challenge in ecology. Within assemblages, functional trait dispersion can be used to infer assembly processes, but this inference could depend on the trait considered. Here, using both single and multiple trait‐based approaches, we analysed dispersion patterns for alpha (i.e., related to niche partitioning) and beta (i.e., related to environmental tolerance) traits in freshwater fish assemblages and characterized how trait dispersion patterns vary along environmental gradients at large spatial scale. Location Western Palaearctic, 290 river catchments. Time period Contemporary. Major taxa studied Freshwater fish. Methods Based on freshwater fish occurrence records in 290 European river catchments, we computed dispersion indices (mean pairwise distance) using standardized effect sizes for each single trait and multiple traits. We then used linear models including climatic, geo‐morphological, biotic and human‐related factors to determine the key drivers shaping freshwater fish dispersion patterns across Europe. Results We highlighted spatial variation in trait dispersion, with both underdispersion and overdispersion simultaneously observed for a given trait, but also distinct patterns of trait dispersion, even within beta and alpha traits. We provided evidence that elevation range and current and past climatic conditions mainly structured trait dispersion patterns. Finally, our results revealed that spatial patterns in trait dispersion based on multiple traits were less pronounced than those based on individual traits. Main conclusions Our results highlighted that traits showed different spatial and environmental patterns, reflecting different ecological patterns. This could lead to potential problems when using functional indices computed on multiple traits and challenges their relevance to describe diversity patterns and to infer the assembly processes shaping community structure.