Biodiversity Institute, University of Kansas, Dyche Hall, 1345 Jayhawk Boulevard, Lawrence, KS 66045, USA.
Proc Natl Acad Sci U S A. 2009 Nov 17;106 Suppl 2(Suppl 2):19644-50. doi: 10.1073/pnas.0901637106. Epub 2009 Sep 23.
Estimating actual and potential areas of distribution of species via ecological niche modeling has become a very active field of research, yet important conceptual issues in this field remain confused. We argue that conceptual clarity is enhanced by adopting restricted definitions of "niche" that enable operational definitions of basic concepts like fundamental, potential, and realized niches and potential and actual distributional areas. We apply these definitions to the question of niche conservatism, addressing what it is that is conserved and showing with a quantitative example how niche change can be measured. In this example, we display the extremely irregular structure of niche space, arguing that it is an important factor in understanding niche evolution. Many cases of apparently successful models of distributions ignore biotic factors: we suggest explanations to account for this paradox. Finally, relating the probability of observing a species to ecological factors, we address the issue of what objects are actually calculated by different niche modeling algorithms and stress the fact that methods that use only presence data calculate very different quantities than methods that use absence data. We conclude that the results of niche modeling exercises can be interpreted much better if the ecological and mathematical assumptions of the modeling process are made explicit.
通过生态位模型来估计物种的实际和潜在分布区域已经成为一个非常活跃的研究领域，但该领域的一些重要概念问题仍然存在混淆。我们认为，通过采用限制“生态位”的定义，可以增强概念的清晰度，从而使基本概念（如基础生态位、潜在生态位和现实生态位以及潜在和实际分布区域）的操作定义成为可能。我们将这些定义应用于生态位保守性的问题，解决了保守的是什么，并通过一个定量的例子展示了如何衡量生态位的变化。在这个例子中，我们展示了生态位空间极其不规则的结构，认为这是理解生态位进化的一个重要因素。许多看似成功的分布模型忽略了生物因素：我们提出了解释来解释这个悖论。最后，我们将物种出现的概率与生态因素联系起来，讨论了不同生态位模型算法实际计算的对象是什么，并强调了仅使用存在数据的方法与使用缺失数据的方法计算的是非常不同的数量这一事实。我们得出的结论是，如果明确建模过程的生态和数学假设，那么对生态位模型研究结果的解释会好得多。
