HR: 11:45h
AN: B42A-06    [Abstracts]
TI: Wildfire, channel disturbance, and stream temperature: spatio-temporal patterns and associations with the distribution of fish and amphibians in central Idaho
AU: * Dunham, J B
EM: jbdunham@fs.fed.us
AF: U.S. Forest Service, Boise Aquatic Sciences Laboratory, 322 East Front Street, Suite 401, Boise, ID 83702 United States
AU: Luce, C H
EM: cluce@fs.fed.us
AF: U.S. Forest Service, Boise Aquatic Sciences Laboratory, 322 East Front Street, Suite 401, Boise, ID 83702 United States
AU: Rosenberger, A E
EM: arosenberger@fs.fed.us
AF: University of Idaho Ecohydraulics Research Group, 322 East Front Street, Suite 340, Boise, ID 83702 United States
AU: Gutierrez, B
EM: bgutierrez@fs.fed.us
AF: University of Idaho Ecohydraulics Research Group, 322 East Front Street, Suite 340, Boise, ID 83702 United States
AU: Nagel, D E
EM: dnagel@fs.fed.us
AF: U.S. Forest Service, Boise Aquatic Sciences Laboratory, 322 East Front Street, Suite 401, Boise, ID 83702 United States
AU: Rieman, B E
EM: brieman@fs.fed.us
AF: U.S. Forest Service, Boise Aquatic Sciences Laboratory, 322 East Front Street, Suite 401, Boise, ID 83702 United States
AB: Temperature is a critical factor in stream ecosystems, and one that is very likely to be altered by wildfire and associated channel disturbance. In central Idaho streams, temperatures after wildfires may increase following loss of shade from riparian vegetation, and changes in channel structure that increase exposure to solar radiation and decreased hyporheic exchanges. To examine the spatio-temporal aspects temperature in relation to these influences, we employed three approaches: a long-term pre-post fire comparison of temperatures between a pair of streams, one burned and one unburned; a short-term pre-post fire comparison of a burned and unburned stream with spatially extensive data; a short-term comparative study of spatial variability in temperatures using a "space for time" substitutive design. These three approaches provided key insights into the value of each study approach and revealed some expected and some surprising associations between temperature and occurrence of native trout and tailed frogs. To further understand potential mechanisms influencing stream temperature, we used field-validated estimates of solar radiation to model the effects of riparian shade from remotely sensed vegetation data. These models confirmed the importance of riparian influences linked to wildfire for stream temperature in our study system. The collective results of this work highlight the importance of spatio-temporal variability in study designs to quantify the effects of wildfire and disturbance on stream temperatures, and the implications of stream temperature for aquatic species in a broad landscape context.
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2005 Joint Assembly