Starzomski Brian M, Parker Raenelle L, Srivastava Diane S
Biodiversity Research Centre, University of British Columbia, 6270 University Boulevard, Vancouver BC V6T1Z4, Canada.
Ecology. 2008 Jul;89(7):1921-30. doi: 10.1890/07-0418.1.
What are the local community consequences of changes in regional species richness and composition? To answer this question we followed the assembly of microarthropod communities in defaunated areas of moss, embedded in a larger moss "region." Regions were created by combining moss from spatially distinct sites, resulting in regional species pools that differed in both microarthropod richness and composition, but not area. Regional effects were less important than seasonality for local richness. Initial differences in regional richness had no direct effect on local species richness at any time along a successional gradient of 0.5-16 months. The structure of the regional pool affected both local richness and local composition, but these effects were seasonally dependent. Local species richness differed substantially between dates along the successional gradient and continued to increase 16 months after assembly began. To the best of our knowledge, this is the first critical test of saturation theory that experimentally manipulates regional richness. Further, our results failed to support the most important mechanisms proposed to explain the local richness-regional richness relationship. The results demonstrate that complicated interactions between assembly time, seasonality, and regional species pools contribute to structuring local species richness and composition in this community.
区域物种丰富度和组成的变化会对当地群落产生哪些影响？为了回答这个问题，我们追踪了嵌入在一个更大的苔藓“区域”中的苔藓缺动物区微型节肢动物群落的聚集情况。这些区域是通过将来自空间上不同地点的苔藓组合而成的，从而形成了微型节肢动物丰富度和组成不同但面积相同的区域物种库。对于当地的丰富度而言，区域效应不如季节性重要。在0.5 - 16个月的演替梯度上的任何时候，区域丰富度的初始差异对当地物种丰富度都没有直接影响。区域库的结构影响了当地的丰富度和组成，但这些影响取决于季节。沿着演替梯度，不同日期的当地物种丰富度差异很大，并且在聚集开始16个月后仍持续增加。据我们所知，这是对通过实验操纵区域丰富度的饱和理论的首次关键检验。此外，我们的结果未能支持为解释当地丰富度与区域丰富度关系而提出的最重要机制。结果表明，聚集时间、季节性和区域物种库之间复杂的相互作用有助于构建该群落中当地物种的丰富度和组成。
