LOCAL AND LANDSCAPE INFLUENCE ON AMPHIBIAN OCCURRENCE AND ABUNDANCE

The traditional emphasis in ecology on local species interactions has recently broadened to include landscape‐level processes. I used data from a seven‐year survey of ponds in northern Switzerland to judge the relative contributions of local and landscape influences to the occurrence and density of larvae of eight amphibian species. Each pond was sampled twice each year using pipe samples and dip nets. Analyses evaluated support for a series of alternative models, some suggested by current ideas in aquatic ecology and others designed to reveal the impact of key variables. Results strongly supported models that include both local and landscape covariates. Species differed in preference for permanent or temporary ponds, high‐ or low‐predator ponds, and landscapes within forested or open areas. The occurrence of all species was positively correlated with the densities of other species, suggesting that competition was less important than variation in quality among sites. The results emphasize the importance of local processes in governing the status of populations, because even landscape‐level effects were probably caused by availability of habitat during the terrestrial stage, rather than by metapopulation processes.