Small mammal response to habitat change following fire in the taiga of southeastern Manitoba

Abstract

The influence of fire on small mammal populations was investigated in the taiga of southeastern Manitoba. Small mammals were sampled by annual removal trapping in six different habitats over twenty-five years at Taiga Biological Station (TBS). Changes in temporal patterns of short-term abundance and long-term population synchronicity were investigated for fluctuating numbers of small mammals. The southern red-backed vole (Clethrionomys gapperi),the deer mouse (Peromyscus maniculatus), and the masked shrew (Sorex cinereus), were the three most common small mammals captured. Examination of population fluctuations revealed that while fire-induced changes in food availability, cover and moisture were likely responsible for differences in small mammal abundance, populations of individual species were alternatively affected by unknown, large-scale, synchronizing influences. This discovery became evident through the common occurrence of similar peak abundance years for C. gapperi, regardless of habitat-type or distance between sampling sites. Additionally, the examination of annual combined small mammal biomass revealed a distinct pattern, with a repetitive maxima occurring every 3- to 4- yrs at TBS across all six sites...