Metapopulation moments: coupling, stochasticity and persistence
Metapopulation moments: coupling, stochasticity and persistence
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DOI：
10.1046/j.1365-2656.2000.00430.x
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发表时间：
2000-09-01
影响因子：
4.8
通讯作者：
Keeling, MJ
中科院分区：
文献类型：
--
作者：
Keeling, MJ
1.空间异质性长期以来被视为增加持久性的可靠手段。在这里，一个分析模型来考虑的变化，因此，持久性的随机集合种群。该模型依赖于一种新的矩封闭技术，这相当于假设人口规模的对数正态分布。当亚种群间的混合很大时，单物种模型表现出最大的持久性，因此空间异质性是没有好处的。这一结果通过对集合种群的随机模拟得到了证实.相比之下，天敌模型表现出最大的持久性的中间水平的耦合。当耦合度太低时，各亚种群之间的拯救效应不足以维持动态，而当耦合度太高时，所有的空间异质性都丧失了.单物种和双物种模型之间的行为差异可以归因于天敌系统的振荡性质。
1. Spatial heterogeneity has long been viewed as a reliable means of increasing persistence. Here, an analytical model is developed to consider the variation and, hence, the persistence of stochastic metapopulations. This model relies on a novel moment closure technique, which is equivalent to assuming log-normal distributions for the population sizes.2. Single-species models show the greatest persistence when the mixing between subpopulations is large, so spatial heterogeneity is of no benefit. This result is confirmed by stochastic simulation of the full metapopulation.3. In contrast, natural-enemy models exhibit the greatest persistence for intermediate levels of coupling. When the coupling is too low, there are insufficient rescue effects between the subpopulations to sustain the dynamics, whereas when the coupling is too high all spatial heterogeneity is lost.4. The difference in behaviour between the one- and two-species models can be attributed to the oscillatory nature of the natural-enemy system.