Phytogeography of Sand Dunes in the Great Basin and Mojave Deserts

Abstract

A floristic survey of twenty stabilized and unstabilized sand dunes in the Great Basin and Mojave Deserts was conducted over a 9-year period. The relative ages of dunes were determined by the number of endemic, psammophytic and azonal taxa at each dune. The relationships among older dunes were then analysed by two-way indicator species analysis (TWINSPAN) and Sorensen's coefficient of similarity (CC,) applied to the psammophytic taxa. These relationships were used to propose routes of psammophyte migration during the Holocene, taking into account climatic change and physiographic complexity in the Great Basin and Mojave Deserts. A total of 166 taxa was documented, representing eightyeight genera and twenty-seven families of vascular plants. Approximately 95% of the taxa was indigenous. Eureka, Big and Kelso dunes were the oldest dunes included in the