Banks Sam C, Davies Ian D, Cremona Teigan, Davies Hugh F, Carey Alexander R, Cary Geoffrey J
Research Institute for the Environment and Livelihoods, Faculty of Science and Technology Charles Darwin University Casuarina Northern Territory Australia.
Fenner School of Environment and Society The Australian National University Canberra Australian Capital Territory Australia.
Ecol Evol. 2024 Dec 16;14(12):e70681. doi: 10.1002/ece3.70681. eCollection 2024 Dec.
Dispersal is a fundamental ecological process that influences population dynamics and genetic diversity and is therefore an important component of the models used to simulate population responses to environmental change. We considered informed dispersal in relation to settlement location, where individuals could optimise selection of settlement location with regard to per capita resource availability and investigated the importance of this type of informed dispersal for simulated demography and genetic diversity under different biological and environmental scenarios. We used an individual-based simulation model scaled with reference to the ecology of small mammals in fire prone savanna ecosystems. We simulated demographic and genetic processes under informed and uninformed dispersal across several scenarios of life history, environmental heterogeneity (patch size and patch dynamics) and dispersal distance. The effect of the dispersal method on population size far outweighed that of dispersal distance under all combinations of habitat quality, temporal dynamics, patch size and dispersal distance modelled. The effects of habitat patch size and habitat dynamics (representing temporal change in habitat quality such as that potentially generated by disturbance) were low under most of the scenarios modelled. Informed dispersal influenced genetic diversity and differentiation, but the effects were weaker than those of dispersal distance. The genetic effect of informed dispersal occurred through the effect on genetic diversity of the overall metapopulation, while the dispersal distance influenced gene flow and genetic diversity within subpopulations. Informed dispersal was less effective in increasing population size in models of a long-lived species with overlapping generations. This was particularly true when habitat quality was dynamic and natal dispersal choices did not result in lifelong habitat quality outcomes. Our results suggest that including informed decision-making in dispersal in simulation models leads to different projections of demography, genetic diversity and susceptibility to environmental change.
扩散是一个基本的生态过程，它影响种群动态和遗传多样性，因此是用于模拟种群对环境变化反应的模型的重要组成部分。我们考虑了与定居地点相关的明智扩散，即个体可以根据人均资源可用性优化定居地点的选择，并研究了这种明智扩散在不同生物和环境情景下对模拟人口统计学和遗传多样性的重要性。我们使用了一个基于个体的模拟模型，该模型参照易发生火灾的稀树草原生态系统中小型哺乳动物的生态学进行了缩放。我们模拟了在明智扩散和非明智扩散情况下，跨越几种生活史、环境异质性（斑块大小和斑块动态）和扩散距离情景下的人口统计学和遗传过程。在模拟的所有栖息地质量、时间动态、斑块大小和扩散距离组合下，扩散方式对种群大小的影响远远超过扩散距离的影响。在大多数模拟情景下，栖息地斑块大小和栖息地动态（代表栖息地质量的时间变化，如可能由干扰产生的变化）的影响较小。明智扩散影响遗传多样性和分化，但其影响比扩散距离的影响弱。明智扩散的遗传效应是通过对整个集合种群遗传多样性的影响而产生的，而扩散距离影响亚种群内的基因流动和遗传多样性。在具有重叠世代的长寿物种模型中，明智扩散在增加种群大小方面效果较差。当栖息地质量动态变化且出生时的扩散选择不会导致终身栖息地质量结果时，情况尤其如此。我们的结果表明，在模拟模型中纳入扩散中的明智决策会导致人口统计学、遗传多样性和对环境变化敏感性的不同预测。
