Grant: Discovery Grants Program - Individual

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.