Dispersal and metapopulation stability.
Dispersal and metapopulation stability.
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作者：
Wang S;Haegeman B;Loreau M
种群动态受到局部和空间因素的共同调节。这些因素可能会以不同的方式影响当地种群和整个集合种群的动态。先前的研究表明，分散可以稳定当地人口；然而，由于分散也往往会增加空间同步性，因此其对集合种群稳定性的净影响一直存在争议。在这里，我们提出了一个简单的集合种群模型，用于研究分散与其他空间和局部过程的相互作用如何影响随机环境中集合种群的时间变异性。我们的结果表明，在同质的集合种群中，扩散的局部稳定和空间同步效应相互抵消，因此扩散对集合种群的变异性没有影响。该结果对于局部和空间参数的中等异质性是稳健的。然而，当局部和空间动态表现出高度异质性时，扩散可以通过各种机制稳定或破坏集合种群动态。我们的研究结果具有重要的理论和实践意义。我们表明，分散在集合种群动态中作为空间种内互利共生的一种形式发挥作用，并且它对集合种群稳定性的影响与种间竞争对当地群落稳定性的影响相反。我们的结果还表明，保护廊道的设计应考虑种群动态的空间异质性，以最大限度地提高种群稳定性。
Metapopulation dynamics are jointly regulated by local and spatial factors. These factors may affect the dynamics of local populations and of the entire metapopulation differently. Previous studies have shown that dispersal can stabilize local populations; however, as dispersal also tends to increase spatial synchrony, its net effect on metapopulation stability has been controversial. Here we present a simple metapopulation model to study how dispersal, in interaction with other spatial and local processes, affects the temporal variability of metapopulations in a stochastic environment. Our results show that in homogeneous metapopulations, the local stabilizing and spatial synchronizing effects of dispersal cancel each other out, such that dispersal has no effect on metapopulation variability. This result is robust to moderate heterogeneities in local and spatial parameters. When local and spatial dynamics exhibit high heterogeneities, however, dispersal can either stabilize or destabilize metapopulation dynamics through various mechanisms. Our findings have important theoretical and practical implications. We show that dispersal functions as a form of spatial intraspecific mutualism in metapopulation dynamics and that its effect on metapopulation stability is opposite to that of interspecific competition on local community stability. Our results also suggest that conservation corridors should be designed with appreciation of spatial heterogeneities in population dynamics in order to maximize metapopulation stability.