Dissertation Research: Constraints on Invasion by a Nitrogen-fixing Woody Shrub and Consequences for Resident Grassland Species

论文研究：固氮木本灌木入侵的限制及其对常驻草原物种的影响

• 批准号: 0073068
• 负责人: Carla D'Antonio
• 金额: $ 0.72万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-15 至 2002-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0073068&HistoricalAwards=false
• 关键词: Dissertation; Research; Constraints; Invasion; Nitrogen

0073068D'AntonioInvasions by wood shrubs (particularly those that fix nitrogen) into grasslands have received much attention, yet we do not understand the role that N-fixation plays in the invasion process. In particular, we do not know what constraints may be imposed by soil-borne mutualists on fixation efficiency, nor the degree to which nutrient limitation of the resident community contributes to the competitive advantage of N-fixation. This research will investigate three questions that address constraints on a nitrogen-fixing shrub's ability to invade a coastal California grassland habitat, and the consequences of that fixation for resident species interactions: (1) How does the success of colonization by broom into grassland habitat change with nutrient limitation of the resident species? (2) How does availability or quality of Rhizobium innoculum affect this species" ability to invade and fix nitrogen? (3) How does enrichment of soil by N-fixation affect species interactions? Coastal California grasslands offer an ideal opportunity to perform this research because they lack a significant native N-fixing component, are themselves nitrogen limited, and are currently experiencing dramatic invasions by several introduced N-fixing shrubs.

0073068D'Antonio 木灌木（特别是固氮灌木）对草原的入侵受到了广泛关注，但我们并不了解固氮在入侵过程中所起的作用。 特别是，我们不知道土传共生体可能会对固氮效率施加哪些限制，也不知道居民群落的养分限制在多大程度上有助于固氮的竞争优势。 这项研究将调查三个问题，解决固氮灌木入侵加州沿海草原栖息地的能力的限制，以及固氮灌木对常驻物种相互作用的影响：（1）金雀花成功定殖到草原栖息地如何改变与常驻物种的营养限制有关吗？ （2）接种根瘤菌的可用性或质量如何影响该物种入侵和固氮的能力？（3）固氮使土壤富集如何影响物种相互作用？加利福尼亚沿海草原提供了进行这项研究的理想机会，因为它们缺乏重要的天然固氮成分，本身的氮含量有限，并且目前正遭受几种引入的固氮灌木的严重入侵。