Socolar Jacob, Washburne Alex
Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey 08544.
Am Nat. 2015 Sep;186(3):333-47. doi: 10.1086/682362. Epub 2015 Jul 30.
Understanding the role of predation in regulating prey diversity is a major goal in ecology, with profound consequences for community dynamics, ecosystem structure, and conservation practice. Deterministic differential equation models predict that some predation regimes, such as prey-switching predation, should promote prey coexistence and increase prey diversity. However, such models do not capture stochastic population fluctuations that are ubiquitous in empirical study sites and nature reserves. In this article, we examine the effects of prey-switching predation on the species richness of prey communities with demographic noise. We show that in finite, discrete prey populations, the ability of prey-switching predation to promote diversity depends on the carrying capacity of the prey community and the richness of the source pool for prey. Identical predation regimes may have opposite effects on prey diversity depending on the size and productivity of the habitat or the metacommunity richness. Statistical properties of the fluctuations of prey populations determine the effect of stabilizing mechanisms on species richness. We discuss the implications of this result for empirical studies of predation in small study areas and for the management of small nature reserves.
理解捕食在调节猎物多样性中的作用是生态学的一个主要目标，对群落动态、生态系统结构和保护实践有着深远影响。确定性微分方程模型预测，一些捕食模式，如猎物转换捕食，应该会促进猎物共存并增加猎物多样性。然而，这类模型没有考虑到在实证研究地点和自然保护区普遍存在的随机种群波动。在本文中，我们研究了猎物转换捕食对存在种群统计学噪声的猎物群落物种丰富度的影响。我们表明，在有限的、离散的猎物种群中，猎物转换捕食促进多样性的能力取决于猎物群落的承载能力和猎物源库的丰富度。相同的捕食模式可能对猎物多样性产生相反的影响，这取决于栖息地的大小和生产力或集合群落的丰富度。猎物种群波动的统计特性决定了稳定机制对物种丰富度的影响。我们讨论了这一结果对小型研究区域捕食实证研究以及小型自然保护区管理的意义。
