Using thinning as a management tool for gypsy moth: the influence on small mammal abundance

Silvicultural manipulations may be used to reduce forest susceptibility or vulnerability to defoliation by the gypsy moth. The effects of this management strategy on small mammal abundance were determined by pitfall trapping small mammals 1 year before silvicultural thinnings and for 3 years following thinning in a deciduous montane forest. Sorex cinereus (masked shrew) was the most frequently captured small mammal, followed by Peromyscus spp. (white-footed and deermice) and Clethrionomys gapperi (redback vole). We found significant differences between thinned and reference stands in total small mammal and Peromyscus spp. abundance. There were no significant changes in S. cinereus and C. gapperi abundance as a result of thinning. The response of the small mammal community reflects the increased complexity of understory vegetation found on the study site as a result of thinning. Principal components analysis results indicated that both vegetation richness and abundance correspond with thinning treatment and likely indirectly affect small mammal abundance. Increased complexity may improve habitat quality, as well as enhancing invertebrate food supply, thereby influencing small mammals.