Changes in small mammal communities after fire in northcentral Ontario.

Abstract

Changes in the small mammals community in recently logged upland black spruce Picea mariana and mixed wood stands near Manitouwadge, Ontario, were documented after a light fire in early summer and after a severe fire in late summer. Populations on the 2 burns were similar in numbers of small mammals and in the composition, diversity, and evenness of the small mammal community. Following fire, southern red-backed voles (Clethrionomys gapperi) declined rapidly to rare status and deer mice (Peromyscus maniculatus) increased within 1 yr to population level 2-25 times those in unburned stands. Numbers of masked shrews (Sorex cinereus) declined and numbers of least chipmunks (Eutamias minimus) increased following the fall fire but not after the spring fire. Diversity and evenness of the small mammal community declined markedly following fire. Deer mouse populations on the burns showed a greater reproductive performance than those on unburned sites but were similar in most demographic variables to those on new clearcuts. Recent burns may act as dispersal sinks for deer mice and provide habitat for colonization.-Author