Department of Biology and the Ecology Center, Utah State University, Logan, Utah 84322, USA.
Am Nat. 2010 Feb;175(2):E35-43. doi: 10.1086/649578.
It is generally accepted that local species richness at a site reflects the combined influence of local and regional processes. However, most empirical studies evaluate the influence of either local environmental variables or regional enrichment but not both simultaneously. Here we demonstrate the importance of combining these processes to understand continental-scale richness patterns in breeding birds. We show that neither regional enrichment nor the local environment in isolation is sufficient to characterize observed patterns of species richness. Combining both sets of variables into a single model results in improved model fit and the removal of residual spatial autocorrelation. At short timescales, local processes are most important for determining local richness, but as the timescale of analysis increases, regional enrichment becomes increasingly important. These results emphasize the need for increased integration of multiple scales of processes into models of species richness.
普遍认为，一个地点的本地物种丰富度反映了本地和区域过程的综合影响。然而，大多数实证研究评估的是本地环境变量或区域富集的影响，但不是同时评估两者。在这里，我们展示了将这些过程结合起来以理解繁殖鸟类大陆尺度丰富度模式的重要性。我们表明，区域富集或孤立的本地环境都不足以描述观察到的物种丰富度模式。将这两组变量结合到一个单一的模型中，可以提高模型的拟合度，并消除剩余的空间自相关性。在短时间尺度上，本地过程对确定本地丰富度最为重要，但随着分析时间尺度的增加，区域富集变得越来越重要。这些结果强调了需要将多个尺度的过程更深入地整合到物种丰富度模型中。
