The Legacy of Human Cadaver Decomposition on Soil Biological Structure and Function

As cadavers decompose, they release nutrient-rich fluids into the underlying soil, which can have significant impacts on associated microbial and arthropod community structure and function. How these changes alter soil biogeochemical cycles is relatively unknown and may prove useful in the identification of carrion decomposition islands that have long lasting, focal ecological effects. This study investigated the spatial (0 to 5 m from human cadavers) and temporal (3 to 732 days) soil bacterial community structure and function, and soil arthropod community structure associated with human cadaver decomposition. We observed strong evidence of a predictable response to cadaver decomposition that varies over space in soil bacterial and arthropod community structure, and carbon (C) mineralization and microbial substrate utilization patterns. Bacterial community composition and function also exhibited temporal relationships; whereas arthropod community composition did not. The starting cadaver mass and cumulative precipitation explained bacterial abundance and microbial activity more effectively than accumulated degree days. Furthermore, microbial communities were sensitive to the introduction of vertebrate carrion as they diverged from baseline levels and did not recover for approximately two years. These data are valuable for understanding ecosystem function surrounding carrion decomposition islands and can be applicable to environmental bio-monitoring and forensic sciences.