Restoration of land exploited for natural resources is a legal mandate for many industries, yet there are many unresolved questions about how to meet restoration goals efficiently and effectively. This proposal capitalizes on a rare situation in which the needs of industry to restore native vegetation to a previously mined tract of land, mesh with the interests of ecological researchers interested in testing the importance of biodiversity to restored ecosystem function. The McLaughlin Reserve (250 ha) is being transformed from active gold mine into a University of California research station by the Homestake Mining Company, which will spend in excess of $500,000 over the next several years to plant native shrubs and trees. This scale of restoration creates a unique opportunity to implement a long-term study that addresses basic and applied issues. This SGER project would help create a large-scale, long-term experiment examining the effects of species diversity and spatial structure of chaparral and oak woodland plant communities on soil development, plant competition, animal communities, and species invasions. This scale of manipulation with trees and shrubs is unique and will produce a lasting opportunity for both research and education in community and restoration ecology.