Stability and species richness in complex communities
Stability and species richness in complex communities
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DOI：
10.1046/j.1461-0248.2000.00144.x
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发表时间：
2000-09-01
期刊：
影响因子：
8.8
通讯作者：
Gross, K
中科院分区：
文献类型：
--
作者：
Ives, AR;Klug, JL;Gross, K
同时使用数值模拟和分析方法，我们研究了生态群落的稳定性如何取决于它们所包含的物种数量。为了研究复杂的社区，我们从模块化的“子社区”中构建社区，这些子社区可以具有任意的社区结构;例如，子社区可以由捕食者和猎物物种对，猎物三人组，专业捕食者和通才捕食者或任何相互作用的物种组成。通过从亚群落构建整个群落，我们可以在不改变群落结构的情况下改变群落中物种的数量。我们进一步假设，在不同亚群落中具有相同生态作用的物种对其他物种的人均种群增长率起着相加作用。在这些假设下，来自不同亚群落的物种之间的相互作用对群落水平的稳定性没有影响，而群落水平的稳定性是通过在不同亚群落中具有相同生态作用的物种的组合密度的变化来衡量的。此外，增加物种丰富度（即组成群落的亚群落数量）只有在引入对环境波动作出不同反应的物种时，才能增加群落一级的稳定性。因此，我们的研究结果支持“保险假说”，即物种丰富度增加社区水平的稳定性，确保在一个社区的一些物种是容忍不同的环境波动。
Using both numerical simulations and analytical methods, we investigate how the stability of ecological communities depends on the number of species they contain. To investigate complex communities, we construct communities from modular "subcommunities" that can have arbitrary community structure; e.g. subcommunities could consist of pairs of predator and prey species, trios of prey, specialist predator and generalist predator, or any collection of interacting species. By building entire communities from subcommunities, we can change the number of species in the community without changing community structure. We further suppose that species sharing the same ecological role in different subcommunities act additively on the per capita population growth rates of other species. Under these assumptions, the interactions between species from different subcommunities have no effect on community-level stability, measured by the variability in the combined densities of species sharing the same ecological role in different subcommunities. Furthermore, increasing species richness (i.e. the number of subcommunities comprising the community) increases community-level stability only when it introduces species that respond differently to environmental fluctuations. Therefore, our results support the "insurance hypothesis" that species richness increases community-level stability by insuring that some species in a community are tolerant of different environmental fluctuations.