Nitrogen Fixation, Alkaloid Metabolism, and Defoliation: Interactions in the Bush Lupine, Lupinus Arboreus (Ecology)

固氮在农业生态系统和自然生态系统中都是新氮素的重要来源。这项研究提出了一项关于固氮对自然生态系统的影响的调查-加州沿海以羽扇豆属为主的草原。这项研究将集中在两个方面的固定：第一，植物之间的固定率的变化模式是什么？其次，落叶对植物的固氮率和生物碱水平有何影响？羽扇豆碱能合成生物碱，这是一种对脊椎动物和无脊椎动物草食动物都有效的含氮毒素。由于生物碱含有氮，固氮率也会影响生物碱的合成。另一方面，对叶片的伤害会增加生物碱的浓度，这种浓度通常与氮源无关。Bentley博士将在冬春假期间参加加州大学戴维斯分校海洋实验室(BML)举办的生态学野外课程，这是一门位于戴维斯的秋季生态学研究生课程(由那里的生态学研究生课程授课)，并为该课程的海岸和田间生态学的本科生提供咨询和建议。此外，她还将参加每周一次的研讨会项目和研究生研讨会系列。该项目进一步推动了VPW计划的目标，即：(1)为妇女提供机会，在NSF资助的工程和科学学科中发展她们的职业生涯；(2)通过提高受雇于工业、政府和学术机构的女科学家和工程师的知名度，鼓励妇女追求科学和工程事业。通过鼓励妇女参与科学，这是对国家未来科学活力的宝贵投资。

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.