标题： 时间可变的扩散和种群动态可以加速入侵物种的扩散 显示英文标题

标题： Temporally variable dispersal and demography can accelerate the spread of invading species

摘要： 我们分析了局部人口统计和扩散的时间变异如何共同影响入侵物种的扩散速率。 我们的模型结合了状态结构化的局部人口统计（由积分或矩阵投影模型指定）与一般扩散分布，这些分布可能依赖于个体或其父母的状态，并且允许在局部人口统计和扩散距离的频率及分布中存在非常一般的平稳时间变化模式。 我们证明了之前针对更通用模型推导出的渐近扩散速率及其对参数的敏感性的表达式仍然成立。 利用这些结果，我们表明随机的时间变化可以加速种群扩散。 如果人口统计变化与扩散变化正相关，例如高繁殖年份同时也是幼体倾向于远离父母定居的年份，那么人口统计变化可以进一步加速扩散。 一个用于入侵植物（多年生辣根菜，Lepidium latifolium）斑块增长和扩散的简单模型展示了这些效应，并表明它们可能对入侵波的预测速度产生显著影响。 在入侵物种扩散的理论和实证文献中，扩散的时间变化都很少受到关注。 我们的结果表明，这种情况需要改变。 显示英文摘要

摘要： We analyze how temporal variability in local demography and dispersal combine to affect the rate of spread of an invading species. Our model combines state-structured local demography (specified by an integral or matrix projection model) with general dispersal distributions that may depend on the state of the individual or its parent, and it allows very general patterns of stationary temporal variation in both local demography and in the frequency and distribution of dispersal distances. We show that expressions for the asymptotic spread rate and its sensitivity to parameters, that have been derived previously for less general models, continue to hold. Using these results, we show that random temporal variability in dispersal can accelerate population spread. Demographic variability can further accelerate spread if it is positively correlated with dispersal variability, for example if high-fecundity years are also years in which juveniles tend to settle further away from their parents. A simple model for the growth and spread of patches of an invasive plant (perennial pepperweed, Lepidium latifolium) illustrates these effects and shows that they can have substantial impacts on the predicted speed of an invasion wave. Temporal variability in dispersal has gotten very little attention in both the theoretical and empirical literatures on invasive species spread. Our results suggest that this needs to change.