Wildfire, channel disturbance, and stream temperature: spatio-temporal patterns and associations with the distribution of fish and amphibians in central Idaho

Temperature is a critical factor in stream ecosystems, and one that is altered by wildfire and related channel disturbances. 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; and 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. The 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.