Elkin Ché M, Possingham Hugh
Ecology Centre, School of Integrative Biology, University of Queensland, St. Lucia, Queensland 4072, Australia.
Am Nat. 2008 Oct;172(4):563-75. doi: 10.1086/590962.
The fundamental processes that influence metapopulation dynamics (extinction and recolonization) will often depend on landscape structure. Disturbances that increase patch extinction rates will frequently be landscape dependent such that they are spatially aggregated and have an increased likelihood of occurring in some areas. Similarly, landscape structure can influence organism movement, producing asymmetric dispersal between patches. Using a stochastic, spatially explicit model, we examine how landscape-dependent correlations between dispersal and disturbance rates influence metapopulation dynamics. Habitat patches that are situated in areas where the likelihood of disturbance is low will experience lower extinction rates and will function as partial refuges. We discovered that the presence of partial refuges increases metapopulation viability and that the value of partial refuges was contingent on whether dispersal was also landscape dependent. Somewhat counterintuitively, metapopulation viability was reduced when individuals had a preponderance to disperse away from refuges and was highest when there was biased dispersal toward refuges. Our work demonstrates that landscape structure needs to be incorporated into metapopulation models when there is either empirical data or ecological rationale for extinction and/or dispersal rates being landscape dependent.
影响集合种群动态（灭绝和再定殖）的基本过程通常取决于景观结构。增加斑块灭绝率的干扰往往依赖于景观，以至于它们在空间上是聚集的，并且在某些区域发生的可能性增加。同样，景观结构会影响生物的移动，导致斑块间的扩散不对称。我们使用一个随机的、空间明确的模型，研究扩散率与干扰率之间依赖于景观的相关性如何影响集合种群动态。位于干扰可能性较低区域的栖息地斑块将经历较低的灭绝率，并起到部分避难所的作用。我们发现部分避难所的存在会提高集合种群的生存能力，并且部分避难所的价值取决于扩散是否也依赖于景观。有点违反直觉的是，当个体大多从避难所扩散出去时，集合种群的生存能力会降低，而当扩散偏向避难所时，生存能力最高。我们的研究表明，当有经验数据或生态学依据表明灭绝和/或扩散率依赖于景观时，景观结构需要纳入集合种群模型。
