Climate, Habitat and Land-use Effects on California Vernal Pool Communities

Biodiversity at different spatial scales is affected by many processes, including habitat size, climate, and human activities. Vernal pools are seasonal freshwater wetlands found throughout California’s Central Valley. They support high levels of endemism and only 10% of this habitat remains in California. This study used two previously collected vernal pool plant and invertebrate datasets to understand how land-use, climate, and pool size influence diversity of vernal pool taxonomic and functional groups at local, regional, and biogeographic scales. Plant richness generally increased with latitude and decreased with measures of pool size while invertebrate richness generally increased with measures of pool size. Native plant gamma diversity was the only factor with a negative association with land use. Latitude, climate, pool characteristics, and land-use all contributed to richness in at least one of the functional groups. This study highlights how diversity of plant and invertebrate functional groups responds to factors at different spatial scales, which should also be considered in restoration and management.