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在过去150年中，人类活动已被人类活动彻底改变，美国大陆是美国大陆最大的生物群落之一。最广泛，最明显的植被的变化是木本植物以牺牲草，莎草和福克斯为代价的膨胀。这项研究将在内华达山脉的山地草地上探讨以下一般问题，在那里发生了鼠尾草的扩张：1）是否可以解释任何生态过程可以解释当前的鼠尾草和草药的模式？ 2）这些社区的当前变化趋势是什么，3）恢复草本物种的障碍是什么？这将结合实验和观察性研究的结合，以检查鼠尾草和草本植物之间的相互作用。实验将涉及大牛的独特，较小的地鼠的排他性，去除植被（剪裁）和水操作。此外，还将在其初始建立阶段的一系列草地修复地块中进行实验。这些实验以及详细的观察性研究将使PI能够阐明限制扩展的鼠尾草社区中草本物种的因素。希望拟议的研究不仅能为该系统的当前恢复计划提供一个可靠的生态框架，而且还将有助于解决更广泛的问题，即将一般生态学理论用于特定地点的恢复问题。