HR: 08:30h
AN: NB41E-01 INVITED     [Abstracts]
TI: Theory Can Help Structure Regression Models for Projecting Stream Conditions Under Alternative Land Use Scenarios
AU: * Van Sickle, J
EM: VanSickle.John@epa.gov
AF: U.S. Environmental Protection Agency, Western Ecology Division, 200 SW 35th, Corvallis, OR 97333 United States
AU: Baker, J
EM: Baker.Joan@epa.gov
AF: U.S. Environmental Protection Agency, Western Ecology Division, 200 SW 35th, Corvallis, OR 97333 United States
AU: Herlihy, A
EM: herlihy.alan@epa.gov
AF: Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR 97333 United States
AB: We built multiple regression models for Emphemeroptera/ Plecoptera/ Tricoptera (EPT) taxon richness and other indicators of biological condition in streams of the Willamette River Basin, Oregon, USA. The models were used to project the changes in condition that would be expected in all 2-4th order streams of the 30000 sq km basin under alternative scenarios of future land use. In formulating the models, we invoked the theory of limiting factors to express the interactive effects of stream power and watershed land use on EPT richness. The resulting models were parsimonious, and they fit the data in our wedge-shaped scatterplots slightly better than did a naive additive-effects model. Just as theory helped formulate our regression models, the models in turn helped us identify a new research need for the Basin's streams. Our future scenarios project that conversions of agricultural to urban uses may dominate landscape dynamics in the basin over the next 50 years. But our models could not detect any difference between the effects of agricultural and urban development in watersheds on stream biota. This result points to an increased need for understanding how agricultural and urban land uses in the Basin differentially influence stream ecosystems.
UR: http://oregonstate.edu/Dept/pnw-erc/
DE: 0400 Biogeosciences
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly