HR: 09:30h
AN: B41A-05    [Abstracts]
TI: Hydrogeomorphic Classification and Functional Composition of Benthic Communities in the Pacific Northwest Mountains
AU: * Bledsoe, B P
EM: bbledsoe@engr.colostate.edu
AF: Department of Civil Engineering , Colorado State University, Fort Collins, CO 80523 United States
AU: Poff, N L
EM: poff@lamar.colostate.edu
AF: Department of Biology , Colorado State University, Fort Collins, CO 80523 United States
AB: We examine variation in insect species traits in the context of a multi-scale hydrogeomorphic classification of streams in mountainous regions of the Pacific Northwest. Using insect data from over 250 streams in Oregon and Washington, we focus on key species traits that explain significant variation in community trait composition across a gradient of hydrogeomorphic disturbance regimes. Site-specific predictions of flow regime, valley setting, geomorphic type, and substrate characteristics derived exclusively from common geospatial data are used individually and in combination to construct a priori and a posteriori physical classifications that are geographically independent. The relative strengths of the classification schemes are assessed by the extent to which within-class similarity in functional composition exceeds the similarity between classes. Given the fundamental role of interactions between flow regime and geomorphic context in structuring insect communities, process-based classifications that integrate hydrologic and geomorphic characteristics offer an attractive means for understanding how environmental drivers vary with landscape context and stratifying bioassessment sites within heterogeneous regions.
DE: 1824 Geomorphology (1625)
DE: 1871 Surface water quality
SC: Biogeosciences [B]
MN: 2005 Joint Assembly