Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755, USA.
Ecology. 2012 Dec;93(12):2728-35. doi: 10.1890/12-0797.1.
The importance of negative intraspecific density dependence to promoting species coexistence in a community is well accepted. However, such mechanisms are typically omitted from more explicit models of community dynamics. Here I analyze a variation of the Rosenzweig-MacArthur consumer-resource model that includes negative intraspecific density dependence for consumers to explore its effect on the coexistence of multiple consumers feeding on a single resource. This analysis demonstrates that a guild of multiple consumers can easily coexist on a single resource if each limits its own abundance to some degree, and stronger intraspecific density dependence permits a wider variety of consumers to coexist. The mechanism permitting multiple consumers to coexist works in a fashion similar to apparent competition or to each consumer having its own specialized predator. These results argue for a more explicit emphasis on how negative intraspecific density dependence is generated and how these mechanisms combine with species interactions to shape overall community structure.
种内密度制约对于促进群落中物种共存的重要性已被广泛认可。然而，在更明确的群落动态模型中，这些机制通常被忽略。本文分析了包含消费者种内密度制约的 Rosenzweig-MacArthur 消费-资源模型的一个变体，以探讨其对单一资源上多个消费者共存的影响。分析表明，如果每个消费者都在某种程度上限制自身的丰度，那么一个由多个消费者组成的类群就可以很容易地在单一资源上共存，而更强的种内密度制约则允许更多种类的消费者共存。允许多个消费者共存的机制的工作方式类似于明显竞争或每个消费者都有自己专门的捕食者。这些结果表明，需要更明确地强调种内密度制约是如何产生的，以及这些机制如何与物种相互作用结合来塑造整体群落结构。
