Bauer Barbara, Vos Matthijs, Klauschies Toni, Gaedke Ursula
Department of Ecology and Ecosystem Modeling, Institute for Biochemistry and Biology, University of Potsdam, Am Neuen Palais 10, D-14469 Potsdam, Germany.
Am Nat. 2014 Mar;183(3):394-409. doi: 10.1086/674906. Epub 2014 Feb 5.
The concept that diversity promotes reliability of ecosystem function depends on the pattern that community-level biomass shows lower temporal variability than species-level biomasses. However, this pattern is not universal, as it relies on compensatory or independent species dynamics. When in contrast within-trophic level synchronization occurs, variability of community biomass will approach population-level variability. Current knowledge fails to integrate how species richness, functional distance between species, and the relative importance of predation and competition combine to drive synchronization at different trophic levels. Here we clarify these mechanisms. Intense competition promotes compensatory dynamics in prey, but predators may at the same time increasingly synchronize, under increasing species richness and functional similarity. In contrast, predators and prey both show perfect synchronization under strong top-down control, which is promoted by a combination of low functional distance and high net growth potential of predators. Under such conditions, community-level biomass variability peaks, with major negative consequences for reliability of ecosystem function.
群落水平的生物量比物种水平的生物量表现出更低的时间变异性。然而，这种模式并非普遍存在，因为它依赖于补偿性或独立性的物种动态。相反，当营养级内同步发生时，群落生物量的变异性将接近种群水平的变异性。目前的知识未能整合物种丰富度、物种间功能距离以及捕食和竞争的相对重要性如何结合起来驱动不同营养级的同步。在这里，我们阐明了这些机制。激烈的竞争促进了猎物的补偿动态，但在物种丰富度和功能相似性增加的情况下，捕食者可能同时越来越同步。相反，在强大的自上而下控制下，捕食者和猎物都表现出完美的同步，这是由捕食者低功能距离和高净生长潜力的组合所促进的。在这种情况下，群落水平的生物量变异性达到峰值，对生态系统功能的可靠性产生重大负面影响。
