SGER: Climatically Induced Nonequilibria Determine Temporal Metacommunity Dynamics

2005年冬天，南加州打破了几个世纪以来的降水纪录。这是一次千载难逢的紧急机会，可以衡量沙漠生产力的大幅自然增长对沙漠啮齿动物群落组织的影响。此外，这样一个及时的事件可以用来将西南沙漠中经过充分研究的啮齿动物群落与群落生态学中的一个新范式--元群落概念--结合起来。元群落结构描述了当地动物群落的区域水平特征，这种特征应该以可预测的方式变化，因为在高生产力时期之后，沙漠生态系统的特征将恢复到相对低的生产力。将在莫哈韦国家保护区对预测进行检验，初步描述整个保护区30个啮齿动物群落的结构。根据建议的资助，每个社区将被抽样两次，未来的资金将用于继续监测元社区结构。一套统计分析将物种组成的变化分解为局部(物种环境相互作用)和区域(扩散效应)影响，这将检验集合群落概念的预测。

During the winter of 2005, centuries long records of precipitation were broken in southern California. This represents an urgent, once in a lifetime opportunity to measure the effects of a large natural increase in desert productivity on the community organization of desert rodents. Moreover, such a timely event can be used to integrate the well-studied rodent communities of southwestern deserts with a new paradigm in community ecology, the metacommunity concept. Metacommunity structure describes regional level characteristics of local animal communities, which should vary in predictable ways as the period of high producivity is followed by a return to the relative low productivity that characterizes desert ecosystems. Predictions will be examined in the Mojave National Preserve with an initial characterization of the structure of 30 rodent communities throughout the preserve. Each community will be sampled twice under proposed funding and future funding will be pursued for continued monitoring of metacommunity structure. A suite of statistical analyses will decompose variation in species composition into local (species environment interactions) and regional (dispersal effects) influences, which will provide a test of the predictions of the metacommunity concept.