Methods for Assessment of Species Richness and Occupancy Across Space, Time, Taxonomic Groups, and Ecoregions

We aimed to develop and evaluate practical methods to estimate species richness the number of native species and occupancy the probability that a given location is occupied by a species of diverse taxonomic groups across space and time and in diverse ecosystems. Our work is relevant to the needs of the Department of Defense to assess and monitor native species and to evaluate the potential effects of land use and management actions on native species. This project addressed five major objectives. First, we assessed relations between environmental variables and species richness at nested spatial extents. Second, we developed guidelines for periodicity of sampling. Third, we tested methods for estimating species richness of multiple taxonomic groups on the basis of spatial variation in occurrence or heterogeneity of one group. Fourth, we examined the extent to which occupancy could provide a foundation for measuring species richness. Fifth, we investigated potential responses of species richness and occupancy to manageable environmental changes, and meaningful scales of sampling for detection of biological effects of environmental change.