Shtilerman Elad, Stone Lewi
Porter School of Environmental Studies, Tel Aviv University, Ramat Aviv, IL 6997801, Israel
Zoology Department, Tel Aviv University, Ramat Aviv, IL 6997801, Israel School of Mathematical and Geospatial Sciences, RMIT University, Melbourne, Victoria 3000, Australia.
Proc Biol Sci. 2015 May 7;282(1806):20150203. doi: 10.1098/rspb.2015.0203.
A spatial metapopulation is a mosaic of interconnected patch populations. The complex routes of colonization between the patches are governed by the metapopulation's dispersal network. Over the past two decades, there has been considerable interest in uncovering the effects of dispersal network topology and its symmetry on metapopulation persistence. While most studies find that the level of symmetry in dispersal pattern enhances persistence, some have reached the conclusion that symmetry has at most a minor effect. In this work, we present a new perspective on the debate. We study properties of the in- and out-degree distribution of patches in the metapopulation which define the number of dispersal routes into and out of a particular patch, respectively. By analysing the spectral radius of the dispersal matrices, we confirm that a higher level of symmetry has only a marginal impact on persistence. We continue to analyse different properties of the in-out degree distribution, namely the 'in-out degree correlation' (IODC) and degree heterogeneity, and find their relationship to metapopulation persistence. Our analysis shows that, in contrast to symmetry, the in-out degree distribution and particularly, the IODC are dominant factors controlling persistence.
空间集合种群是由相互连接的斑块种群组成的镶嵌体。斑块之间复杂的定殖路径由集合种群的扩散网络控制。在过去二十年中，人们对揭示扩散网络拓扑结构及其对称性对集合种群持续性的影响产生了浓厚兴趣。虽然大多数研究发现扩散模式的对称程度会增强持续性，但也有一些研究得出结论认为对称性至多只有微小影响。在这项工作中，我们为这场争论提出了一个新视角。我们研究了集合种群中斑块的入度分布和出度分布的性质，它们分别定义了进入和离开特定斑块的扩散路径数量。通过分析扩散矩阵的谱半径，我们证实更高的对称程度对持续性只有边际影响。我们继续分析入度 - 出度分布的不同性质，即“入度 - 出度相关性”（IODC）和度异质性，并找出它们与集合种群持续性的关系。我们的分析表明，与对称性不同，入度 - 出度分布，特别是IODC是控制持续性的主导因素。
