Effects of wildfire severity on small mammals in northern Arizona ponderosa pine forests

Abstract

We examined effects of a varied-severity wildfire on the community structure of small mammals and populations of the 2 most abundant species, the deer mouse (Peromyscus maniculatus) and the gray-collared chipmunk (Tamias cinereicollis), in northern Arizona ponderosa pine (Pinus ponderosa) forests. We examined 2 fire severities and compared them to unburned controls. The average number of species captured was similar among the 3 plot types: 2.0 on high-severity plots, 3.0 on moderate-severity plots, and 3.5 on control plots. However, the species composition differed among these types. Specifically, gray-collared chipmunks were not captured on high- severity plots in the first year following the fire. We found no statistically significant difference among treatments for gray-collared chipmunk densities even though they were not captured on high-severity plots (P = 0.074). Deer mouse densities on high-severity fire plots were greater than on control plots (P = 0.028) and were marginally greater than on moderate-severity plots (P = 0.051). We did not find a significant difference between moderate and control plots (P = 0.25). Deer mouse densities were strongly correlated with forb (P = 0.002) and shrub ( P = 0.038) cover in a stepwise linear regression (adjusted R² = 0.67). Based on these results, we suggest that a consideration of fire severity in a structural sense does not provide a clear picture of the impacts of wildfires or prescribed fires on the small mammal community. We propose that the composition of the postfire understory plant community must also be considered.

Citation

Kyle, Sean C.; Block, William M. 2000. Effects of wildfire severity on small mammals in northern Arizona ponderosa pine forests. In: Moser, W. Keith; Moser, Cynthia E., eds. Fire and forest ecology: innovative silviculture and vegetation management. Tall Timbers Fire Ecology Conference Proceedings, No. 21. Tallahassee, FL: Tall Timbers Research Station: 163-168