Many management efforts focus on conserving species, but a major challenge to this strategy is the uncertainty surrounding how species’ geographic ranges may shift in response to global change – including climate and land use change. An alternative strategy is to identify areas of the earth that support the many facets of biodiversity. However, this strategy relies on having knowledge of how biodiversity responds to geodiversity - the variety of abiotic features and processes – in the Anthropocene. Here we explore how remote sensing illuminates the relationship between biodiversity and geodiversity along gradients of stress to better understand what components of geodiversity or indicators of human land-use will aid in our ability to provide continuous estimates of taxonomic and functional diversity in the continental United States. More specifically, we ask how does tree diversity (alpha, beta, and gamma) vary across space in response to different geodiversity variables related to stress. We fit a generalized linear model with a spatial random effect for region for a subset of non-correlated geodiversity variables. We included data on functional traits matched to abundance data for trees from the U.S. Forest Service’s Forest Inventory and Analysis data. Data on geodiversity and anthropogenic stressors were derived from NASA satellite products.
Results/Conclusions
We found that the response of tree diversity (taxonomic and functional) showed varying responses to geodiversity variables across space. Furthermore, coefficient estimates for geodiversity predictor variables not only varied by magnitude across the different metrics of diversity (i.e., alpha, beta, and gamma), but also by sign. This approach will also enable us to generate a continuous map of functional and taxonomic diversity across the United States for trees that takes into consideration how different geodiversity variables may have spatially varying influences on different aspects of tree biodiversity. In the future, coupling this approach to functional traits measured from spectral data, rather than on the ground observations, may provide a means of gap-filling between sites with spectral data to provide spatially continuous maps of plant functional diversity based on spectral data.