Kirsch, J.E and J.T. Peterson. 2014. A multi-scaled approach to evaluating the fish assemblage structure within southern Appalachian streams USA. Transactions of the American Fisheries Society. 143:1358-1371.
There is considerable uncertainty regarding the relative roles of stream habitat, landscape characteristics, and interspecific interactions in structuring stream fish assemblages. We evaluated the relative importance of environmental characteristics and species interactions on fish occupancy, at local and landscape scales, within the upper Little Tennessee River Basin, Georgia and North Carolina. Using a quadrat sample design, fishes were collected at 525 channel units within 48 study reaches during two consecutive years. We 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 suggested that the fish assemblage within the Little Tennessee River Basin was hierarchically structured and primarily influenced by stream size and spatial context, urban land coverage, and channel unit types. Landscape scale factors (i.e., urban land coverage, stream size and spatial context) largely constrained the fish assemblage structure at a stream reach and local scale factors (i.e., channel unit types) influenced fish distribution within stream reaches. Our study demonstrates the utility of a multi-scaled approach and the need to account for the inter-scale interactions of factors influencing assemblage structure prior to monitoring fish assemblages, developing biological management plans, or allocating management resources throughout a stream system.