Co‐variation of fish assemblages, flow regimes and other habitat factors in French rivers

摘要: Summary 1. Using data from 270 minimally disturbed river sites distributed across France, we examined relationships between fish assemblages and four sets of explanatory variables representing climate, position in the network, geomorphology flow regime (temporal variation). 2. Flow regimes, represented by 157 hydrological indices, were derived 763 gauging stations unmodified flows. Principal components analysis was used to reduce indices nine non-redundant variables, regionalisation then transfer sampling sites. 3. Climate, network geomorphology, collectively referred as ‘habitat’ factors, mean January July temperature, distance source, altitude width, depth, slope, sediment size % lotic habitat. 4. Partial constrained ordination (pCCA) showed that individually explained 9.7% variability assemblages, however variation decreased only 3.4% when habitat removed. 5. Our study co-variation need be accounted for avoid overestimating importance biological–hydrological relationships. Failing do so may have important implications development environmental prescriptions, apparent biological responses altered regimes are likely confounded associated with variability.