CRB: Context-Dependent Constraints on Sagebrush-Herb Dynamics in Sierra Nevada Meadow

CRB：内华达山脉草甸山艾树草本动力学的上下文相关约束

• 批准号: 9815813
• 负责人: Carla D'Antonio
• 金额: $ 30.5万
• 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: 1999
• 资助国家: 美国
• 起止时间: 1999-02-01 至 2003-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9815813&HistoricalAwards=false
• 关键词: CRB; Context; Dependent; Constraints; Sagebrush

9815813D'Antonio One of the largest biomes in the continental United States, the semi-arid rangeland, has been dramatically altered by human activities over the past 150 years. The most widespread and conspicuous vegetation change has been the expansion of woody plant at the expense of grasses, sedges and forbs. This research will explore the following general questions in the montane meadows of the Sierrra Nevada where the expansion of sagebrush has occured: 1) Are any ecological processes that can explain the current patterns of sagebrush and herbs? 2) What are the current trends of change in these communities and 3) What are the barriers to the recovery of the herbaceous species? This will be done with a combination of experimental and observational studies to examine the interactions between sagebrush and herbaceous species. The experiments will involve large cattle exclosures, smaller gopher exclosures, removal of vegetation (clipping) and water manipulations. In addition, experiments will also be conducted in a series of meadow restoration plots that are in their initial stages of establishment. These experiments along with the detailed observational studies will enable the PI to elucidate the factors that constrain herbaceous species within the expanding sagebrush community. It is hoped that not only will the proposed research contribute a solid ecological framework to current restoration plans for this system, but it also will help address the more widespread problem of using general ecological theory to site-specific restoration issues.

9815813D'Antonio 美国大陆最大的生物群落之一，半干旱牧场，在过去 150 年里因人类活动而发生了巨大的变化。最广泛和最显着的植被变化是木本植物的扩张，其代价是草、莎草和杂草的减少。本研究将探讨在内华达山脉山地草甸中鼠尾草扩张的以下一般问题：1）是否有任何生态过程可以解释目前鼠尾草和草本植物的模式？ 2) 这些群落目前的变化趋势是什么？ 3) 草本物种恢复的障碍是什么？这将通过实验和观察研究相结合来完成，以检查山艾树和草本物种之间的相互作用。实验将涉及大型牛围栏、小型地鼠围栏、植被清除（修剪）和水处理。此外，还将在一系列处于初期建设阶段的草地恢复地块中进行实验。这些实验以及详细的观察研究将使 PI 能够阐明限制草本物种在不断扩大的山艾树群落中的因素。希望所提出的研究不仅将为该系统当前的恢复计划提供坚实的生态框架，而且还将有助于解决将一般生态理论应用于特定地点恢复问题的更广泛的问题。