Response of small mammals to clear-cutting and precommercial thinning in mixed forests of southeastern Quebec

The impacts of forest management on habitat characteristics, species richness, and population dynamics of small mammals remain ambiguous. We studied the response of small-mammal populations, including snowshoe hares, to clear-cutting with protection of advanced regeneration and soils (CPRS) and precommercial thinning (PCT). We compared stands recently treated by CPRS or PCT with established stands dominated by deciduous or coniferous trees in two large blocks of mixed forests. We measured habitat components and abundance of small mammals in the four stand types. Trees (DBH greater than or equal to 9 cm) became very rare in CPRS stands and remained at low density in PCT stands, which stimulated the growth of herbs and seedlings, resulting in increased lateral cover. Tree harvest also generated coarse woody debris in CPRS stands, which did not persist in PCT stands. Small mammals responded to these disturbances in a species-specific manner but, overall, relative abundance and species richness of small mammals were lower in PCT stands than in CPRS and closed stands. Our results suggest that forest managers should exclude some stands from PCT following CPRS or natural perturbations, to maintain ecosystem diversity at the landscape level.