Poethke Hans Joachim, Hovestadt Thomas
University of Würzburg, Ecological Field Station, Glashüttenstrasse 5, 96181 Rauhenebrach, Germany.
Proc Biol Sci. 2002 Mar 22;269(1491):637-45. doi: 10.1098/rspb.2001.1936.
Based on a marginal value approach, we derive a nonlinear expression for evolutionarily stable (ES) dispersal rates in a metapopulation with global dispersal. For the general case of density-dependent population growth, our analysis shows that individual dispersal rates should decrease with patch capacity and-beyond a certain threshold-increase with population density. We performed a number of spatially explicit, individual-based simulation experiments to test these predictions and to explore further the relevance of variation in the rate of population increase, density dependence, environmental fluctuations and dispersal mortality on the evolution of dispersal rates. They confirm the predictions of our analytical approach. In addition, they show that dispersal rates in metapopulations mostly depend on dispersal mortality and inter-patch variation in population density. The latter is dominantly driven by environmental fluctuations and the rate of population increase. These conclusions are not altered by the introduction of neighbourhood dispersal. With patch capacities in the order of 100 individuals, kin competition seems to be of negligible importance for ES dispersal rates except when overall dispersal rates are low.
基于边际价值方法，我们推导出了具有全局扩散的集合种群中进化稳定（ES）扩散率的非线性表达式。对于密度依赖型种群增长的一般情况，我们的分析表明，个体扩散率应随斑块容量降低，并且在超过一定阈值后随种群密度增加。我们进行了一系列基于个体的空间明确模拟实验，以检验这些预测，并进一步探究种群增长率变化、密度依赖、环境波动和扩散死亡率对扩散率进化的相关性。这些实验证实了我们分析方法的预测。此外，实验表明集合种群中的扩散率主要取决于扩散死亡率和斑块间种群密度的变化。后者主要由环境波动和种群增长率驱动。引入邻域扩散并不会改变这些结论。当斑块容量约为100个个体时，亲属竞争对于ES扩散率似乎不太重要，除非总体扩散率较低。
