The Vegetation and Flora of Edwards Air Force Base, Western Mojave Desert, California

Abstract

Edwards Air Force Base extends over 121,000 ha in the Antelope Valley of the western Mojave Desert, with much of the area part of a closed endorheic basin that held the Pleistocene Lake Thompson. Notable topographic features are Rogers, Rosamond and Buckhorn dry lakes, while rounded domes and scattered hills are present to the north and east. Elevation gradients are limited, ranging from a low of 690 m to 1044 m near the eastern margin. Diverse communities of saltbush scrub dominate the lower plains, while creosote bush scrub and Joshua tree woodlands are present away from the old lake basin. In many ways EAFB is a biogeographic crossroads with the broader central Mojave Desert to the east, Owens Valley and Great Basin to the north, and cismontane Central Valley and foothills to the west. The flora as currently known contains 403 vascular plant taxa, with 324 (80%) of these native. The eight largest families comprise more than 68% of the flora, led by the Asteraceae with 84 taxa (72 native). Annual plants make up over two-thirds of the total flora.