Department of Zoology, 451 Birge Hall, University of Wisconsin, Madison, Wisconsin 53706, USA.
Ecology. 2012 Apr;93(4):704-10. doi: 10.1890/11-1797.1.
Local species diversity is maintained over ecological time by a balance between dispersal and species interactions. Local-regional species richness relationships are often used to investigate the relative importance of these two processes and the scales at which they operate. For communities undergoing succession, theory predicts a temporal progression in local-regional species richness relationships: from no relationship to positive linear to saturating. However, observational tests have been mixed, and experiments have been rare. Using a replicated large-scale experiment, we evaluate the impact of two dispersal-governing processes at the regional scale, connectivity and shape of the region (i.e., patches), on the progression of local-regional species richness relationships for plant communities undergoing succession. Regional connectivity accelerates the transition from no relationship to a positive linear relationship, while the shape of the region has no consistent effect nine years post-disturbance. Our results experimentally demonstrate the importance of dispersal in structuring local-regional species richness relationships over time and suggest that conservation corridors among regions can increase local diversity through regional enrichment of plant communities undergoing reassembly.
本地物种多样性通过扩散和物种相互作用之间的平衡在生态时间上得以维持。本地-区域物种丰富度关系通常用于研究这两个过程的相对重要性以及它们作用的尺度。对于正在进行演替的群落，理论预测本地-区域物种丰富度关系会随时间呈现出阶段性变化：从没有关系到正线性关系再到饱和。然而，观测性测试结果不一，实验也很少。本研究使用复制的大规模实验，评估了区域尺度上两个扩散控制过程（连通性和区域形状，即斑块）对经历演替的植物群落本地-区域物种丰富度关系演变的影响。区域连通性加速了从没有关系到正线性关系的转变，而区域的形状在干扰后九年没有一致的影响。我们的实验结果表明，扩散在随时间构建本地-区域物种丰富度关系方面具有重要意义，并表明区域间的保护走廊可以通过植物群落的区域丰富化来增加本地多样性。
