Response of small mammals to clearcutting, burning, and glyphosate application in the Oregon Coast Range

Conversion of hardwood stands to conifers is a common practice in the Oregon Coast Range, but little is known of the effect on small mammals. We sampled small mammals on 3 replicate red alder (Alnus rubra) sites 1 year before and 2 years after the application of forest management treatments. On each site, 1 unit each was (1) left uncut (control), (2) clearcut and broadcast burned, and (3) clearcut and broadcast burned and then sprayed with glyphosate, herbicide. All sites included uncut riparian buffer strips at least 20 m wide. In upslope areas, capture rates of creeping voles (Microtus oregoni; P < 0.001) and vagrant shrews (Sorex vagrans; P = 0.005) increased after logging, while capture rates of Pacific shrews (S. pacificus; P < 0.02) and Trowbridge's shrews (S. trowbridgii; P = 0.006) decreased. For Townsend's chipmunk (Tamias townsendii), capture rates increased in the buffer areas after logging (P < 0.02). Capture rates for deer mice (Peromyscus maniculatus) did not differ among treatments (P > 0.20). Capture rates of the shrew species that declined did not decrease in the buffer areas, indicating riparian buffer strips may support populations of these species up to 2 years after logging. For the 6 species analyzed, changes in capture rates did not differ between areas sprayed with glyphosate and logged, unsprayed areas (Ps > 0.15).