Relationships between deer mice and downed wood in managed forests of southern British Columbia

Abstract

We examined the relationship between deer mice (Peromyscus maniculatus (Wagner)) and downed wood in a low-elevation Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forest and a high-elevation Engelmann spruce (Picea engelmannii Parry ex Engelm.) – subalpine fir (Abies lasiocarpa (Hook.) Nutt.) forest in the south-central interior of British Columbia. We experimentally manipulated the volume of downed wood on clear-cut and forested sites and monitored the response of deer mice with a mark–recapture study to assess population densities and survival and reproduction rates. Populations responded positively to harvesting at the low-elevation but not the high-elevation study area. At the low-elevation study area, the population dynamics of deer mice on clear-cut and forested treatments were not positively associated with patterns of vegetation cover or increasing downed-wood volumes. Instead, populations on clearcuts appeared to increase in response to an unknown factor associated with lower volumes. No relationship was detected between population dynamics of deer mice and downed-wood volumes at the high-elevation site. The population dynamics of deer mice on forests at the high-elevation site appeared to be more closely related to vegetation cover than to downed wood. The results indicated that downed wood is not a critical habitat component for deer mice in the south-central interior of British Columbia.