Smith Matthew J, Sherratt Jonathan A, Lambin Xavier
Computational Ecology and Environmental Science Group, Microsoft Research Limited, Cambridge CB30FB, UK.
J Theor Biol. 2008 Sep 21;254(2):264-74. doi: 10.1016/j.jtbi.2008.05.034. Epub 2008 Jun 1.
Density-dependent dispersal occurs throughout the animal kingdom, and has been shown to occur in some taxa whose populations exhibit multi-year population cycles. However, the importance of density-dependent dispersal for the spatiotemporal dynamics of cyclic populations is unknown. We investigated the potential effects of density-dependent dispersal on the properties of periodic travelling waves predicted by two coupled reaction-diffusion models: a commonly used predator-prey model, and a general model of cyclic trophic interactions. We compared the effects of varying the gradient of both positive and negative density-dependent dispersal rates, to varying the ratio of the (constant) dispersal rates of the two interacting populations. Our comparison focussed on the possible range of wave properties, and on the waves generated by landscape obstacles and invasions. In all scenarios that we studied, varying the gradient of density-dependent dispersal has small quantitative effects on the travelling wave properties, relative to the effects of varying the ratio of the diffusion coefficients.
密度依赖型扩散在整个动物界都有发生，并且已被证明在一些种群呈现多年周期的分类群中存在。然而，密度依赖型扩散对周期性种群时空动态的重要性尚不清楚。我们研究了密度依赖型扩散对两个耦合反应扩散模型所预测的周期性行波特性的潜在影响：一个常用的捕食者 - 猎物模型，以及一个周期性营养相互作用的通用模型。我们比较了改变正密度依赖型扩散率和负密度依赖型扩散率梯度的影响，以及改变两个相互作用种群（恒定）扩散率比值的影响。我们的比较集中在波特性的可能范围，以及由景观障碍和入侵产生的波上。在我们研究的所有情景中，相对于改变扩散系数比值的影响，改变密度依赖型扩散梯度对行波特性只有很小的定量影响。
