Livestock as a tool for the restoration of native biological diversity in California's vernal pool grasslands

California's Central Valley grasslands represent one of the most invaded ecosystems in the United States with the cover of non-native plant species often exceeding 85 percent.  Vernal pools are seasonal wetlands that occur within these grassland systems and serve as a refuge for native species that have adapted to the pools' seasonally flooded and desiccated environment.  More than 90% of the remaining vernal pool grasslands in California are currently and have historically been grazed by livestock.  Historically, grazing was removed from vernal pool grassland properties as non-profit organizations and governmental agencies acquired them for conservation purposes.  I am conducting an experiment to evaluate the long-term effects of grazing exclusion on vernal pool flora and fauna.  Three years of grazing removal led to a significant reduction in vernal pool inundation and decreased diversity of native plant species and invertebrate taxa.  These initial results indicate that grazing plays a major role in maintaining the function and diversity in this ecosystem.