Nitrogen fixation can be a very important source of new nitrogen in both agricultural and natural ecosystems. This study proposes an investigation of the impact of nitrogen fixation in a natural ecosystem---the lupine-dominated grassland of coastal California. The study will focus on two aspects of fixation: first, what is the pattern of variation in fixation rates among the plants? and second, how does defoliation impact on both nitrogen fixation rates and levels of alkaloids in the plants? Lupines synthesize alkaloids, nitrogen-containing toxins effective against both vertebrate and invertebrate herbiovores. Because alkaloids contain nitrogen, nitrogen fixation rates can affect alkaloid synthesis as well. On the other hand, damage to foliage can increase alkaloid concentrations, often independent on the source of nitrogen. Dr. Bentley will participate in a UC (Davis) ecology field course given at Bodega Marine Laboratory (BML) during the winter/ spring break, a Davis-based, fall-quarter graduate course in ecology (given by the Graduate Program in Ecology there) and provide counseling and advice to undergraduate students in the course in Coastal and Field Ecology. In addition she will participate in a weekly seminar program and graduate student seminar series. This project furthers VPW program objectives which are (1) to provide opportunities for women to advance their careers in engineering and in the disciplines of science supported by NSF and (2) to encourage women to pursue careers in science and engineering by providing greater visibility for women scientists and engineers employed in industry, government, and academic institutions. By encouraging the participation of women in science, it is a valuable investment in the Nation's future scientific vitality.
