Nyquist B, Tyson R, Larsen K
University of British Columbia Okanagan, Kelowna, BC, Canada.
Bull Math Biol. 2007 May;69(4):1311-39. doi: 10.1007/s11538-006-9160-2. Epub 2007 Mar 16.
In this paper, we present a model for source-sink population dynamics where the locations of source and sink habitats change over time. We do this in the context of the population dynamics of the North American red squirrel, Tamiasciurus hudsonicus, within a forest environment subject to harvesting and regrowth. Harvested patches of forest are initially sinks, then eventually become source habitat again as the forest regrows. At the same time, each harvested patch is gradually recolonized by squirrels from other forest patches. We are interested in the interaction of forest harvesting dynamics with squirrel population dynamics. This depends on the harvesting schedule, and on the choices squirrels make when deciding whether to settle in a mature forest patch or in a recently harvested patch. We find that the time it takes for a second-growth forest patch to be recolonized at the mature forest level is longer than the time required for the habitat quality to be restored to the mature forest level. We also notice that recolonization pressure decreases squirrel populations in neighbouring patches. The connectivity between forest patches and the cutting schedule used also affect the time course of recolonization and steady-state population levels.
在本文中，我们提出了一个源 - 汇种群动态模型，其中源栖息地和汇栖息地的位置会随时间变化。我们是在北美红松鼠（Tamiasciurus hudsonicus）在一个经历采伐和再生的森林环境中的种群动态背景下进行此项研究的。采伐后的森林斑块最初是汇，然后随着森林再生最终又成为源栖息地。与此同时，每个采伐后的斑块会逐渐被来自其他森林斑块的松鼠重新定殖。我们关注森林采伐动态与松鼠种群动态之间的相互作用。这取决于采伐计划，以及松鼠在决定是在成熟森林斑块还是在最近采伐的斑块中定居时所做出的选择。我们发现，次生林斑块在成熟森林水平上重新定殖所需的时间比栖息地质量恢复到成熟森林水平所需的时间更长。我们还注意到，重新定殖压力会使相邻斑块中的松鼠种群数量减少。森林斑块之间的连通性以及所采用的采伐计划也会影响重新定殖的时间进程和稳态种群水平。
