Gaston Kevin J
Biodiversity and Macroecology Group, Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
Proc Biol Sci. 2009 Apr 22;276(1661):1395-406. doi: 10.1098/rspb.2008.1480. Epub 2009 Feb 25.
Understanding of the determinants of species' geographic range limits remains poorly integrated. In part, this is because of the diversity of perspectives on the issue, and because empirical studies have lagged substantially behind developments in theory. Here, I provide a broad overview, drawing together many of the disparate threads, considering, in turn, how influences on the terms of a simple single-population equation can determine range limits. There is theoretical and empirical evidence for systematic changes towards range limits under some circumstances in each of the demographic parameters. However, under other circumstances, no such changes may take place in particular parameters, or they may occur in a different direction, with limitation still occurring. This suggests that (i) little about range limitation can categorically be inferred from many empirical studies, which document change in only one demographic parameter, (ii) there is a need for studies that document variation in all of the parameters, and (iii) in agreement with theoretical evidence that range limits can be formed in the presence or absence of hard boundaries, environmental gradients or biotic interactions, there may be few general patterns as to the determinants of these limits, with most claimed generalities at least having many exceptions.
对物种地理分布范围限制因素的理解仍未得到很好的整合。部分原因在于对该问题的观点多样，且实证研究在很大程度上滞后于理论发展。在此，我进行一个广泛的概述，汇集许多不同的线索，依次考虑对一个简单单种群方程各项的影响如何能够决定分布范围限制。在每种人口统计学参数中，都有理论和实证证据表明在某些情况下会朝着分布范围限制发生系统性变化。然而，在其他情况下，特定参数可能不会发生此类变化，或者可能朝着不同方向变化，但限制仍然会出现。这表明：（i）从许多仅记录一个人口统计学参数变化的实证研究中，几乎无法明确推断出关于分布范围限制的情况；（ii）需要有记录所有参数变化的研究；（iii）与理论证据一致，即无论是否存在硬边界、环境梯度或生物相互作用都可能形成分布范围限制，对于这些限制的决定因素可能几乎没有普遍模式，大多数声称的普遍性至少都有许多例外情况。
