CRB: Understanding the Regional Distribution of Native Meadow Remnants in Northern California

[903421]了解严重入侵群落中本地物种避难所的性质既是一项科学挑战，也是保护的必要条件。例如，加利福尼亚的草地群落主要由外来的一年生植物主导；残余的本地物种仍然存在，但缺乏定量的知识，他们在哪里和为什么。像生态学中的许多问题一样，这个问题必须在大的空间尺度上解决。这项研究将确定土壤、地形、土地利用和空间隔离如何相互作用，影响加州北部130,000公顷地区原生草甸植物的分布。本文将验证两个主要假设：(1)本地物种多样性在区域尺度上的分布是可预测的；(2)本地物种多样性取决于入侵性和隔离性。第一个假设将通过精心设计的分层抽样制度来解决。第二个假设将通过高度控制的操作实验来解决。这个项目将是在一个高度入侵的陆地群落中，在区域尺度上量化本地和外来物种多样性模式的第一次尝试之一。它也将是第一个研究空间隔离在为本地物种创造避难所方面的作用的研究之一。最后，它旨在为研究区域目前正在进行的生态系统管理工作做出贡献。

9903421HarrisonUnderstanding the nature of refugia for native species in heavily invaded communities is both a scientific challenge and a conservation necessity. For example, California meadow communities are largely dominated by alien annual plants; remnant native species still persist, but there is a lack of quantitative knowledge of where they persist and why. Like many questions in ecology, this one must be addressed at a large spatial scale. This research will determine how soils, topography, land use and spatial isolation interact to affect the distribution of native meadow plants in a 130,000 hectare region of northern California. Two main hypotheses will be tested: (1) The distribution of native diversity is predictable at a regional scale, and (2) native species diversity depends on invasibility and isolation. The first hypotheses will be address by a carefully designed, stratified sampling regime. The second hypothesis will be addressed by highly controlled manipulative experiments. This project will be one of the first attempts to quantify patterns of native and alien species diversity at a regional scale, in a highly invaded terrestrial community. It will also be one of the first studies to examine the role of spatial isolation in creating refugia for native species. Finally, it is designed to contribute to an ecosystem management effort that is currently underway in the study region.