Determining the Spatial Scale of Species' Response to Habitat

Abstract Species respond to habitat at different spatial scales, yet many studies have considered this response only at relatively small scales. We developed a technique and accompanying software (Focus) that use a focal patch approach to select multiple sets of spatially independent sites. For each independent set, regressions are conducted between the habitat variable and counts of species abundance at different scales to determine the spatial scale at which species respond most strongly to an environmental or habitat variable of interest. We applied the technique to determine the spatial scales at which 12 different species of cerambycid beetles respond to forest cover. The beetles responded at different scales, from 20 to 2000 meters. We expect this technique and the accompanying software to be useful for a wide range of studies, including the analysis of existing data sets to answer questions related to the large-scale response of organisms to their environment.