Brooks Christopher P
Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3280, USA.
Ecology. 2006 Apr;87(4):864-72. doi: 10.1890/05-0860.
Among the few universal themes in ecology is that resources, energy, and organisms themselves, are patchily distributed. This patchy distribution imposes a need for some level of dispersal or connectivity among spatially separate patches in order to allow organisms to acquire sufficient resources for survival. To date, general patterns of connectivity have not emerged. This is, in part, because different species respond to different scales of patchiness. I propose an extension of the graph-theoretic approach to control for such differences and reveal potential generalities about how natural populations are organized. Using statistical methods and simple applications of graph theory, continuum percolation, and metapopulation models, I demonstrate a pattern of hierarchical clustering among populations in both a plant-pathogen system at an extent of 1000 m and gene flow in a salamander species across a subcontinental range. Results suggest that some patches or populations have a disproportionately high importance to the maintenance of overall connectivity in the system within and across scales.
生态学中为数不多的普遍主题之一是，资源、能量以及生物体本身都是呈斑块状分布的。这种斑块状分布使得在空间上相互分离的斑块之间需要一定程度的扩散或连通性，以便生物体获取足够的资源来生存。迄今为止，尚未出现连通性的一般模式。部分原因在于，不同物种对不同尺度的斑块化有不同的反应。我提议扩展图论方法，以控制此类差异，并揭示有关自然种群如何组织的潜在普遍性。通过统计方法以及图论、连续渗流和集合种群模型的简单应用，我在一个范围达1000米的植物 - 病原体系统以及一个跨次大陆范围的蝾螈物种的基因流中，展示了种群之间的层次聚类模式。结果表明，一些斑块或种群对于维持系统内和跨尺度的整体连通性具有极高的重要性。
