9412150 Rust This dissertation enhancement grant provides partial support for a U.S. graduate student, Myra E. Barnes, working under the guidance of Dr. Richard W. Rust, of the Department of Biology at the University of Nevada, Reno, to study two species of Acacia trees in northern Botswana. A low rate of seedling establishment has curtailed replacement of trees destroyed as a result of elephant foraging. Observational and experimental methods will be used to determine which biotic and abiotic factors influence the rate of seed production, germination, seedling establishment, and survival of trees to reproductive maturity. The goal of the research is to determine whether pollinators, insect, avian, or mammal seed predators, browsers, soil water potential, fire, or a combination of these or other factors, limit seedling establishment and survival. The research will be conducted at seven existing study sites in four wildlife areas in northern Botswana and two or more additional sites which will be added later in 1994. Staff members from Botswana's Department of Wildlife and National Parks will collaborate with Ms. Barnes on this project. This study will make an important contribution to the understanding of elephant-habitat interactions as they relate to biological diversity in northern Botswana. The grant will also provide support to enable a promising student to establish a strong independent research career. ***
