The relationship between cave biodiversity and available habitat
Aim: The goal of this study was to determine the role habitat availability plays in the distribution of obligate subterranean cave fauna in eastern North America. Location: The numbers of stygobites, troglobites and caves in the counties of the south‐eastern USA were analysed. Methods: The data were characterized by large numbers of zeroes and by spatial clustering of non‐zeroes in five regions. Regression and conditional autoregressive (CAR) models were used to elucidate the patterns and relationships between numbers of species and numbers of caves both locally and regionally. Results: Local effects (regions and numbers of caves in counties) accounted for 45% of the variation in troglobite counts (P =< 0.001) and 24% of the variation in stygobite counts (P =< 0.001). Significant spatial autocorrelation among both stygobites and troglobites (P =< 0.0001) was found as well. Conclusion: Overall, habitat availability as measured by cave numbers influenced species richness. Spatial and regional effects also played an important role in determining the observed distributions of the subterranean fauna. Terrestrial and aquatic communities showed very different patterns in their relationship to habitat and within the different regions.