28th Annual Meeting and Symposium of the
Desert Tortoise Council, February 21-23, 2003
Abstracts

Current Status and Management of Alien Plants and Fire in Desert Tortoise Habitat

M. L. Brooks, T. C. Esque, and J. R. Matchett
U.S. Geological Survey, Las Vegas Field Office, 160 N. Stephanie, Henderson, Nevada 89074

Alien plants and fire have been recognized recently as significant land management problems in desert tortoise habitat. Annual species dominate the alien flora, although only Bromus rubens, Schismus spp., and Erodium cicutarium are currently widespread and abundant. These species can compete with native plants, and B. rubens in particular has contributed to significant increases in fire frequency since the 1970s. Native desert plants are often poorly adapted to fire, and recurrent fire has converted native shrubland to alien annual grassland in some areas. Changes in plant communities caused by alien plants and recurrent fire may negatively affect native animals such as the desert tortoise by altering habitat structure and the species composition of their food plants.

Increased levels of surface disturbing activities, rainfall, and atmospheric nitrogen and carbon dioxide may increase dominance of alien plants and frequency of fire in the future. Land managers should focus on early detection and eradication of new alien species, especially those that pose significant fire threats, and law enforcement to minimize the frequency of ignitions by humans. Additional information on the ecology and effects of invasive plants and fire in the Mojave and Colorado deserts are needed to develop effective management plans.