THE ROLE OF STREAM NETWORK GEOMETRY AND CLIMATE ON THE SPATIAL EXTENT OF AQUATIC-DERIVED RESOURCES IN TERRESTRIAL ENVIRONMENTS
The effects of emergent aquatic insect subsidies are pronounced at the water’s edge, yet less is known about the extent these resources permeate into upland environments: here we assessed the relative role of stream network geometry and climate. We estimated the area at which aquatic derived resources could be detected at 25% of the value at the stream bank (i.e. “stream signature”), for ~1,600 complete stream networks across the contiguous US. We characterized the network geometry with Horton’s Laws and drainage diameter and density and compiled several hydroclimate variables, including mean annual precipitation and estimated flow. Given high in-stream productivity, we found up to 36% of the watershed could be subjected to a 25% stream signature and that the spatial extent was strongly related to stream network density. This work supplements other theoretical developments with more realistic stream networks and demonstrates the utility of a nationally consistent dataset in assessing aquatic-terrestrial resource exchange across broad spatial extents. Further, it provides a spatially explicit prediction of aquatic resource flux which can be tested empirically and improved.
Darin Kopp (Primary Presenter/Author), University of Oklahoma, firstname.lastname@example.org;
Daniel Allen ( Co-Presenter/Co-Author), University of Oklahoma, email@example.com;