Short-Term Effects of Variable-Retention Logging Practices on Terrestrial Gastropods in Coastal Forests of British Columbia

Abstract

Abstract Variable-retention (VR) logging practices provide an alternative to clearcutting, but much uncertainty exists on their effectiveness in maintaining biodiversity. We compared patterns of abundance of terrestrial gastropods in areas subjected to either clearcutting or VR treatments, in relation to an uncut control at six experimental sites in coastal British Columbia before and 2–4 years after logging. Gastropods sensitive to the logging treatments in most comparisons included Haplotrema vancouverense, Pristiloma stearnsii and P. lansingi (as a group), and Striatura pugetensis. Several generalist species showed no response to the treatments, and the abundance of two species (Punctum randolphii and Vespericola columbianus) increased in some logged treatments relative to the control. At sites where trees were retained in small groups (0.2–0.5 ha), the abundance of four species was depressed when compared to the control and pre-logging values. No differences among retention levels of 10%, 20%, and 30%...