Changes in Soil Microbial Activity Following Cadaver Decomposition During Spring and Summer Months in Southern Ontario

Abstract

Bodies are often disposed of clandestinely in environments allowing direct contact with soil yet the impact of cadaver decomposition on the surrounding environment remains generally poorly studied. The microbial load associated with a decomposing body is substantial and it is believed that decomposition has a notable impact on the surrounding soil microbiology. During 2011 and 2012 a study consisting of four experimental trials was undertaken at the University of Ontario Institute of Technology decomposition facility located in Southern Ontario. The study documented the decomposition of human analogues (pig carcasses) and the subsequent microbiological impacts on the soil within the decomposition islands created. Two trials were conducted per year, one in the spring and one in the summer to account for seasonal variations. For each trial, soil samples were collected from three experimental sites and three controls sites over a 3 month period. Sample analysis included soil pH, moisture and microbial activity using a fluorescein diacetate assay. Microbial activity levels between control and experimental samples were compared on each sampling day and overall for all trials. An increase in microbial activity was observed on multiple occasions during the Spring 2011, Summer 2011 and Spring 2012 trial. However, a decrease in microbial activity was observed during the Summer 2012 trial. Soil pH and soil moisture underwent similar fluctuations in control samples and experimental samples pointing to environmental conditions having a strong influence on both these soil parameters.