Department of Entomology and Nematology, University of California Davis, CA, USA.
Department of Biology, Tufts University, MA, USA.
Proc Biol Sci. 2022 Jun 8;289(1976):20220505. doi: 10.1098/rspb.2022.0505.
Dispersal is a key driver of spatial population dynamics. Dispersal behaviour may be shaped by many factors, such as mate-finding, the spatial distribution of resources, or wind and currents, yet most models of spatial dynamics assume random dispersal. We examined the spatial dynamics of a day-flying moth species () that forms mating aggregations on hilltops (hilltopping) based on long-term adult and larval population censuses. Using time-series models, we compared spatial population dynamics resulting from empirically founded hilltop-based connectivity indices and modelled the interactive effects of temperature, precipitation and density dependence. Model comparisons supported hilltop-based connectivity metrics including hilltop elevation over random connectivity, suggesting an effect of hilltopping behaviour on dynamics. We also found strong interactive effects of temperature and precipitation on dynamics. Simulations based on fitted time-series models showed lower patch occupancy and regional synchrony, and higher colonization and extinction rates when hilltopping was included, with potential implications for the probability of persistence of the patch network. Overall, our results show the potential for dispersal behaviour to have important effects on spatial population dynamics and persistence, and we advocate the inclusion of such non-random dispersal in metapopulation models.
扩散是空间种群动态的关键驱动因素。扩散行为可能受到许多因素的影响，例如寻找配偶、资源的空间分布或风和水流等，但大多数空间动态模型都假设随机扩散。我们基于长期的成虫和幼虫种群普查，研究了一种日行性飞蛾物种（）的空间动态，该物种在山顶上形成交配聚集（hilltopping）。使用时间序列模型，我们比较了基于经验的山顶连接性指数的空间种群动态，并对温度、降水和密度依赖性的相互作用效应进行了建模。模型比较支持基于山顶的连接性指标，包括山顶相对于随机连接的海拔高度，这表明 hilltopping 行为对动态有影响。我们还发现温度和降水对动态有很强的交互作用。基于拟合时间序列模型的模拟结果显示，当包括 hilltopping 时，斑块占有率和区域同步性降低，定居和灭绝率升高，这可能对斑块网络的持续存在概率产生影响。总的来说，我们的研究结果表明，扩散行为可能对空间种群动态和持久性产生重要影响，我们提倡在复合种群模型中纳入这种非随机扩散。
