Fish assemblages in Atlantic Forest streams: the relative influence of local and catchment environments on taxonomic and functional species

摘要: Streams are under environmental pressures acting at different scales that influence the ecological organisation of their fish assemblages. However, relative scale-related variables on assemblage composition and function is poorly understood. We evaluated importance local- catchment-scale variables, as well spatial structure sampling sites, in shaping assemblages Atlantic Forest streams. Local-scale were those measured describing local habitat conditions (e.g. depth, substrate type, altitude). Catchment-scale integrating upstream landscape sites catchment land use). Spatial distances calculated from watercourse distance using principal coordinates neighbour matrices. Altogether, 28 seven initially subjected to two processes eliminating co-linearity. Redundancy analysis was applied three matrices (spatial, catchment) quantify variance explained by each matrix. Local more variability both taxonomic functional structure, than variables. also changed along longitudinal gradient, which consequently influenced structure. This pattern anthropogenic alteration non-native species, abundant downstream sites. These results highlight need assess streams scales, especially through use quantitative local-scale metrics, consider effects patterns structuring when developing implementing monitoring programmes, impact studies conservation plans.