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SPATIAL SCALE OF AUTOCORRELATION IN WISCONSIN FROG AND TOAD SURVEY DATA
Citation:
Trenham, P. C. SPATIAL SCALE OF AUTOCORRELATION IN WISCONSIN FROG AND TOAD SURVEY DATA. Presented at 80th Annual Meeting of American Society of Ichthyologists and Herpetologists, La Paz, Mexico, June 14-20, 2000.
Description:
The degree to which local population dynamics are correlated with nearby sites has important implications for metapopulation dynamics and landscape management. Spatially extensive monitoring data can be used to evaluate large-scale population dynamic processes. Our goals in this study were to evaluate the spatial scale at which anuran population dynamics are positively autocorrelated. The basis for this work was Wisconsin's Frog and Toad Survey data. This dataset encompassed 1350 sites in all regions of the state with sufficient data to investigate spatial autocorrelation in eight species. We also obtained monthly weather data for 38 stations in Wisconsin. Our analyses revealed little evidence of positive spatial autocorrelation with most species showing no significant positive autocorrelation even among sites within the shortest distance classes. Although most species showed no regional correlation with rainfall or temperature, early season breeders were positively correlatd with rainfall totals at stations up to 25 km away. These results suggest that the dynamics of these populations are controlled more by local conditions (e.g., habitat, hydroperiod, predators) than by regional forces such as climate, and that regional metapopulations are unlikely to be destabilized by strongly correlated local extinctions.