This project will continue and expand a comparative study of similar, but geographically isolated, semi-arid montane ecosystems in the Peninsular Ranges within the Californian Biogeographic Province. The Parque Nacional San Pedro Martir (SPM) in Baja California, Mexico, and the Mt. San Jacinto State Park (SJ) in southern California have experienced profoundly different management regimes during the 20th century. SJ has been subject to a fire suppression policy since 1900 and to an exclusion of domestic livestock since 1930; in contrast, wildfires remain uncontrolled in SPM but livestock grazing intensity is extremely high. The project will evaluate the result of the differing management strategies on these two ecosystems. Included will be continuing documentation of past and current human use of the two areas, reconstruction of the probable vegetation patterns of the sites prior to European exploitation (based on diaries from the Spanish mission period of the late 18th century), and perfection of computerized geographic information systems for the two areas. The researchers will characterize elevational, latitudinal and longitudinal gradients in both areas and will utilize satellite remote sensing data to reconstruct regional fire histories. The research will provide for an understanding of the controls of biodiversity and of sustainable development in these important habitats and may be of use in analyzing the probable of global environmental change.
