Relative influences of catchment‐ and reach‐scale abiotic factors on freshwater fish communities in rivers of northeastern Mesoamerica

摘要: While the abiotic factors important to freshwater fish assemblages at a reach scale are well understood, studies of larger constraints have yielded variable conclusions, spurring need for further in new biogeographic contexts. This study investigated importance catchment- and reach-scale variation rivers northeastern Mesoamerica. Abiotic variables data from 72 sampling sites on main stem Belize were used with partial constrained ordination determine proportion spatially structured unstructured presence absence, relative abundance, community metrics explained by environmental factors. Results showed that, combined, catchment large portion total assemblage (54-75%), that environment greater (42-63%) than (34-50%). Variables representing landscape position (local elevation, watershed area) their reach-level correlates (channel width, depth variation, substrate) correlated strongly data. Our results suggest landscape-scale stronger influence conditions within our area. These contrast past findings local landscapes low anthropogenic disturbance levels. biodiversity conservation efforts should consider across longitudinal gradient, multi-catchment region is biologically relevant planning coordination