HR: 16:30h
AN: B44B-05    [Abstracts]
TI: Landscape Pattern, Network Structure, and the Distribution of Coastal Cutthroat Trout in Headwater Streams
AU: * Torgersen, C E
EM: ctorgersen@usgs.gov
AF: USGS FRESC, 3200 SW Jefferson Way, Corvallis, OR 97331 United States
AU: Gresswell, R E
EM: bgresswell@usgs.gov
AF: USGS NRMSC, P.O. Box 172780 Montana State University, Bozeman, MT 59717 United States
AU: Bateman, D S
EM: doug_bateman@usgs.gov
AF: Department of Forest Science, 321 Richardson Hall Oregon State University, Corvallis, OR 97331 United States
AU: Hockman-Wert, D P
EM: dhockman-wert@usgs.gov
AF: USGS FRESC, 3200 SW Jefferson Way, Corvallis, OR 97331 United States
AB: Headwater streams are dynamic environments in which landscape characteristics exert strong influences on the distribution of stream fishes. Although geology, topographic factors, and land use have been shown to affect trout population density at a site-specific level, few studies have investigated landscape features associated with the spatial extent and scale of variation of trout distribution in an entire watershed. To evaluate landscape influences on the distribution and abundance of coastal cutthroat trout (Oncorhynchus clarki clarki), we conducted spatially continuous surveys of stream habitat and trout abundance in forty randomly selected watersheds (500-1000 ha) in the Cascades, Coast Range, and Klamath Mountains ecoregions of western Oregon. Our investigation of coastal cutthroat trout populations across a broad range of headwater environments revealed that landscape features, including topography, geology, network structure, annual precipitation, and stand replacement disturbance, were associated with the spatial extent and scale of variation of trout distribution within watersheds. Understanding effects of basin-scale factors on trout distribution and abundance is critical in forested regions such as the Pacific Northwest where resource managers must consider potential impacts of logging on aquatic ecosystems.
UR: http://oregonstate.edu/~torgersc/
DE: 0400 Biogeosciences
DE: 1803 Anthropogenic effects
DE: 1848 Networks
SC: Biogeosciences [B]
MN: 2005 Joint Assembly