A multi-scaled approach to evaluating the fish community structure within southern Appalachian streams

There is considerable uncertainty regarding the relative roles of stream habitat, landscape characteristics, and interspecific interactions in structuring stream fish assemblages. Thus, I evaluated the relative importance of environmental characteristics and species interactions, at local and landscape scales, on fish occupancy within the upper Little Tennessee River basin, Georgia and North Carolina. Using a quadrat sample design, fishes were collected at 525 channel units among 48 study reaches during two consecutive years. I evaluated the relative support for the influence of local- and landscape-scale factors on fish occupancy using multi-scaled, hierarchical, multi-species occupancy models. Modeling results indicated that fish occupancy within stream reaches was most influenced by physical in-stream habitat characteristics and interspecific interactions and fishes occupancy of between stream reaches was most influenced by landscape characteristics. Therefore natural resource managers should consider both local and landscape-scale factors and account for hierarchical theory when allocating management resources.