Why are metapopulations so rare?
Why are metapopulations so rare?
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DOI：
10.1890/11-1814.1
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发表时间：
2012-08-01
期刊：
影响因子：
4.8
通讯作者：
Poethke, Hans Joachim
中科院分区：
文献类型：
--
作者：
Fronhofer, Emanuel A.;Kubisch, Alexander;Poethke, Hans Joachim
在引入大约40年后，元种群概念成为种群生态学的核心。当地人口及其动态可能因分散而耦合的观念，无疑对我们理解人口水平的过程具有重要意义。元种群描述了在灭绝和重新定居的动态平衡中，由（罕见的）分散事件联系在一起的一组亚种群。在已积累的大量文献中，“元人口”一词通常用于非常广泛的意义；大多数时候，它只是暗示了空间异质性。最近的一些评论已经解决了这个问题，并指出，尽管元人口概念很大，而且仍在不断流行，但只有很少的经验例子符合严格的经典元人口（CM）定义。为了理解理论和观察之间的差异，我们使用了一种基于个体的建模方法，该方法使我们能够精确定位CM结构出现所需的环境条件和生活史属性。我们发现，CM动力学被限制在空间结构化但完全占据的种群和全球灭绝种群之间边界的特定参数范围内。考虑到一般的生活史属性，我们的模拟表明，与（大型）脊椎动物相比，CMs更有可能发生在节肢动物物种中。由于特定类型的空间种群结构决定了保护概念，我们的研究结果对保护生物学具有重要意义。我们的模型表明，大多数空间结构的人口是泛型的、不完整的或大陆-岛屿型的，这使得增加连通性（如走廊）的努力值得怀疑。如果观察到真正的CM结构，这意味着焦点元种群处于灭绝的边缘，需要采取严厉的保护措施。
Roughly 40 years after its introduction, the metapopulation concept is central to population ecology. The notion that local populations and their dynamics may be coupled by dispersal is without any doubt of great importance for our understanding of population-level processes.A metapopulation describes a set of subpopulations linked by (rare) dispersal events in a dynamic equilibrium of extinctions and recolonizations. In the large body of literature that has accumulated, the term "metapopulation'' is often used in a very broad sense; most of the time it simply implies spatial heterogeneity. A number of reviews have recently addressed this problem and have pointed out that, despite the large and still growing popularity of the metapopulation concept, there are only very few empirical examples that conform with the strict classical metapopulation (CM) definition.In order to understand this discrepancy between theory and observation, we use an individual-based modeling approach that allows us to pinpoint the environmental conditions and the life-history attributes required for the emergence of a CM structure. We find that CM dynamics are restricted to a specific parameter range at the border between spatially structured but completely occupied and globally extinct populations. Considering general life-history attributes, our simulations suggest that CMs are more likely to occur in arthropod species than in (large) vertebrates.Since the specific type of spatial population structure determines conservation concepts, our findings have important implications for conservation biology. Our model suggests that most spatially structured populations are panmictic, patchy, or of mainland-island type, which makes efforts spent on increasing connectivity (e.g., corridors) questionable. If one does observe a true CM structure, this means that the focal metapopulation is on the brink of extinction and that drastic conservation measures are needed.