Intrinsic and extrinsic drivers of source-sink dynamics

Many factors affect the presence and exchange of individuals among subpopulations and influence not only the emergence, but the strength of ensuing source–sink dynamics within metapopulations. Yet their relative contributions remain largely unexplored. To help identify the characteristics of empirical systems that are likely to exhibit strong versus weak source–sink dynamics and inform their differential management, we compared the relative roles of influential factors in strengthening source–sink dynamics. In a series of controlled experiments within a spatially explicit individual-based model framework, we varied patch quality, patch size, the dispersion of high- and low-quality patches, population growth rates, dispersal distances, and environmental stochasticity in a factorial design. We then recorded source–sink dynamics that emerged from the simulated habitat and population factors. Long-term differences in births and deaths were quantified for sources and sinks in each system and...

诸多因素会影响亚种群间个体的存续与交流，不仅会左右集合种群（metapopulation）内源汇动态（source-sink dynamics）的出现，还会影响该动态后续的强度。然而目前学界对这些因素的相对贡献仍鲜有探索。为了甄别易呈现强/弱源汇动态的实证系统特征，并为其差异化管理提供依据，本研究对比了各影响因素在强化源汇动态过程中的相对作用。本研究基于空间显式个体模型（spatially explicit individual-based model）框架开展了一系列对照实验，采用析因设计（factorial design）操控生境斑块质量、斑块大小、高低质量斑块的空间分布格局、种群增长率、扩散距离以及环境随机性（environmental stochasticity）等变量。随后记录了由模拟生境与种群参数所催生的源汇动态。针对各系统中的源种群与汇种群，我们量化了其长期的出生与死亡差异，并...