Testing the applicability of the facilitation model of community succession in terrestrial heterotrophic communities

在陆地生态系统中，分解是一个连续的过程，主要由昆虫随时间顺序聚集的行动引起，这种现象被称为异养演替。各种分解底物，如动物身体、粪便、枯木、水果和真菌，都有异养演替的记录。与自养演替(即由植物等自养生物主导的时间演替)不同，异养演替发生在相对较小的资源斑块上，只有在资源本身完全耗尽之前才可用。目前，人们对异养演替的动态知之甚少。Connell和Slatyer(1977)所描述的群落演替促进模型，被许多人认为是对异养演替背后的主要原因机制的准确解释，该模型植根于植物和海洋研究，并已广泛应用于异养系统。然而，促进模型并没有受益于分解生态学文献中的任何经验支持，初步工作表明，它不能解释在异养背景下获得的一些结果。这项研究的目标是(I)研究利用各种分解底物的昆虫群落如何对启动演替的自然、大规模干扰作出反应，(Ii)确定调节分解底物的景观环境和人为干扰如何影响异养演替，(Iii)根据物种谱系和形态确定可用于预测资源斑块上昆虫物种发生的特征，以及(Iv)验证促进模型在不同异养系统中的适用性。如果群落演替的促进模式最终被拒绝，这项工作可能会导致范式转变，对分解生态学的所有领域都会产生影响。我也希望这个项目为法医昆虫学中死亡时间间隔估计的综合方法的发展奠定基础。

In terrestrial ecosystems, decomposition is a continuous process caused primarily by the action of insects assembling sequentially over time, a phenomenon referred to as heterotrophic succession. Heterotrophic succession has been documented for a variety of decomposing substrates such as animal carcasses, dung, deadwood, fruits, and fungi. In contrast with autotrophic succession (i.e., temporal succession dominated by autotrophic organisms such as plants), heterotrophic succession occurs on relatively small resource patches that are only available until the resource itself becomes completely exhausted. Currently, very little is known about the dynamics governing heterotrophic succession. The facilitation model of community succession as described by Connell and Slatyer (1977), believed by many to be an accurate explanation of the main causal mechanism behind heterotrophic succession, finds root in plant and marine research and has been liberally carried over to heterotrophic systems. However, the facilitation model has not benefited from any empirical support in the decomposition ecology literature and preliminary work suggests that it cannot explain some of the results obtained in a heterotrophic context. The objectives of this research program are (i) to examine how the insect community that exploits a variety of decomposing substrates responds to natural, large-scale disturbances initiating succession, (ii) to determine how landscape context and anthropogenic disturbances regulating the decomposing substrate affect heterotrophic succession, (iii) to identify traits in terms of species lineage and morphology that can be used to predict insect species occurrence at the resource patch, and (iv) to verify the applicability of the facilitation model in different heterotrophic systems. Should the facilitation model of community succession end up being rejected, this work could lead to a paradigm shift, with consequences for all fields of decomposition ecology. I also expect this program to lay the groundwork for the development of integrated approaches of postmortem interval estimation in forensic entomology.