Amphibian Habitat Associations at Patch and Landscape Scales in the Central Oregon Coast Range

Abstract

We examined capture rates of amphibians in 30 250-300-ha landscapes in the central Oregon Coast Range, Oregon, USA, to better understand multiscale habitat associations. We compared capture rates of 5 species that had 26-79 captures to expected capture rates based on sampling effort in 7 vegetation patch types and 4 species with 208-482 captures in 11 patch types. Capture rates of 8 amphibian species were higher (P< 0.05) in conifer and/or mixed large sawtimber patch types than in other patch types. We also examined associations between landscape-level capture rates and both percent area of patch-type and 8 pattern indices. The percent area of conifer and/or mixed large sawtimber patch types was associated with capture rates of 5 amphibian species, and various pattern metrics were associated with the capture rates of 4 amphibian species. We found that most amphibian species were associated with unique habitat conditions, making managing across amphibian species difficult. Applying the intermediate disturbance hypothesis at the landscape scale may provide a useful management concept for maintaining suitable habitat conditions for a wide diversity of amphibian species. Mature forest area, patch richness, pattern, and composition seemed to be key features associated with amphibian abundance and distribution that should be considered in management plans when biodiversity of amphibians is a management objective.