HR: 09:00h
AN: B41A-03    [Abstracts]
TI: Geomorphic Heterogeneity at the Valley Segment Scale: Effects on Habitat Structure, Aquatic Organisms, and Stream-Riparian Food Web Linkages
AU: * Baxter, C V
EM: baxtcold@isu.edu
AF: Stream Ecology Center, Department of Biological Sciences, Idaho State University, Box 8007, Pocatello, ID 83209 United States
AU: Torgersen, C E
EM: ctorgersen@usgs.gov
AF: U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97331 United States
AB: A distinct domain of heterogeneity at the valley segment scale has long been recognized by geomorphologists, but its implications for stream ecology have received less attention. As opposed to sampling discrete points, stream ecologists' efforts to make maps have generally been applied at only at very large or small spatial scales. We have found mapping of valley segment types a powerful tool for detecting patterns at an intermediate scale, which then sets the stage for interpreting patterns observed at both smaller and larger scales. We report results from a series of studies that describe how valley segment types and their arrangements within river networks affect the expression of habitat structure, the distribution and abundance of species, the makeup of communities, and the flux of resources between aquatic and terrestrial food webs. Study tools such as valley segment mapping provide a more spatially continuous perspective on biophysical heterogeneity in riverine landscapes. In turn, increasing the spatial extent and resolution of data improves the scope of a study, which enhances power to detect patterns and investigate scaling relationships in river networks.
DE: 1824 Geomorphology (1625)
DE: 1845 Limnology
DE: 9810 New fields (not classifiable under other headings)
SC: Biogeosciences [B]
MN: 2005 Joint Assembly