Using exclusion rate to unify niche and neutral perspectives on coexistence
Using exclusion rate to unify niche and neutral perspectives on coexistence
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DOI：
10.1111/oik.04380
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发表时间：
2017-10-01
期刊：
影响因子：
3.4
通讯作者：
Cornell, Stephen J.
中科院分区：
文献类型：
--
作者：
Carmel, Yohay;Suprunenko, Yevhen F.;Cornell, Stephen J.
竞争排斥原理是生态学中最有影响力的概念之一。经典的公式表明，竞争对手物种的相似性和竞争的严重程度之间的相关性，导致快速竞争排斥的物种非常相似，但中性模型表明，相同的物种可以持续竞争很长一段时间。在这里，我们解决了冲突，通过检查两个组件的相似性-生态位重叠和竞争的相似性-和建模的影响，每个排除率（定义为时间的倒数排除）。研究排斥率，而不是传统的关注二元结果（共存与排斥），使我们能够使用相同的货币来检查经典的利基和中立的观点。高生态位重叠加速排斥，但竞争能力的高相似性减缓排斥。这些预测被一个著名的两个物种竞争两种资源的模型所证实。在这两个因素之间的相关性的生态合理的情况下，最强的排斥率可能是在中等相似的物种之间，而非常相似和高度不相似的竞争对手的排斥率非常低。即使在模型中加入少量的人口统计随机性，也会进一步模糊确定性和概率性共存之间的界限。因此，专注于排斥率，而不是共存与排斥的二元结果，可以从竞争性互动中产生各种结果。这种方法可能有助于解释物种共存于不同的竞争社区，并提出了新的问题，为未来的工作。
The competitive exclusion principle is one of the most influential concepts in ecology. The classical formulation suggests a correlation between competitor species similarity and competition severity, leading to rapid competitive exclusion where species are very similar; yet neutral models show that identical species can persist in competition for long periods. Here, we resolve the conflict by examining two components of similarity - niche overlap and competitive similarity - and modeling the effects of each on exclusion rate (defined as the inverse of time to exclusion). Studying exclusion rate, rather than the traditional focus on binary outcomes (coexistence versus exclusion), allows us to examine classical niche and neutral perspectives using the same currency. High niche overlap speeds exclusion, but high similarity in competitive ability slows it. These predictions are confirmed by a well-known model of two species competing for two resources. Under ecologically plausible scenarios of correlation between these two factors, the strongest exclusion rates may be among moderately similar species, while very similar and highly dissimilar competitors have very low exclusion rates. Adding even small amounts of demographic stochasticity to the model blurs the line between deterministic and probabilistic coexistence still further. Thus, focusing on exclusion rate, instead of on the binary outcome of coexistence versus exclusion, allows a variety of outcomes to result from competitive interactions. This approach may help explain species coexistence in diverse competitive communities and raises novel issues for future work.