Landscape structure affects different eastern Ontario anuran species at different spatial scales.

摘要

Many species of anurans (frogs and toads) are experiencing declines in abundance. Research suggests that landscape alteration, particularly the loss of forest and the insertion of roads in landscapes, are important factors contributing to these declines. The purpose of this study was to-answer the following questions: (1) Are abundances of different species of anurans in eastern Ontario most strongly affected by landscape structure at different spatial scales? (2) Does the scale at which each species responds most strongly to landscape structure reflect its dispersal distance? (3) Does each species respond most strongly at different scales to different landscape features (forest cover and paved road density)? and (4) If yes, is the scale of strongest response to percent forest cover or paved road density a better indicator of species dispersal distance? These questions were addressed by measuring population abundance of seven anuran species endemic to eastern Ontario at 34 breeding ponds surrounded by landscapes of varying forest cover and road density. I found that different species were most strongly affected by landscape structure at different scales, ranging from 500 m to 2000 m from the breeding ponds. (Abstract shortened by UMI.)