Little known and little understood: Development of a small wetland assessment field card to identify potential breeding habitat for amphibians

Abstract

The effect of timber harvesting on small wetland habitats and associated amphibians has not been studied in the Pacific Northwest. In 2004, we initiated a study of three forested sites containing 70+ small wetlands in the Nanaimo Lakes area on Vancouver Island to investigate the use of these sites by amphibians before and after harvesting. Before harvesting, the majority of these wetlands were used for breeding by at least one of four aquatic-breeding amphibian species. Use continued after harvesting, with some species apparently drawn to breed in the newly harvested sites in response to reduced canopy cover conditions, which increase water temperature and productivity. Variable retention harvesting methods often use small wetlands as anchor points for retention patches, which protect the integrity of the in-pond environment and provide cover for metamorphs emerging in mid-summer; however, often only the largest wetlands receive retention. Our results indicate that habitat factors beyond wetland size are also important. Based on our research, we developed and tested a wetland field card that forestry personnel in south coastal areas can use to identify small wetlands used by breeding amphibians.