U.S. flag

An official website of the United States government, Department of Justice.

Transient Hypoxia Drives Soil Microbial Community Dynamics and Biogeochemistry During Human Decomposition

NCJ Number
309735
Journal
FEMS Microbiology Ecology Volume: 100 Issue: 10 Dated: 2024
Date Published
2024
Length
25 pages
Annotation

This paper discusses the research methodology and findings from two separate, year-long human decomposition trials, one starting in spring, the second in winter, integrating bacterial and fungal community structure and abundances with soil physicochemistry and biogeochemistry, with the goal being to identify key drivers of microbial community change.

Abstract

Human decomposition in terrestrial ecosystems is a dynamic process creating localized hot spots of soil microbial activity. Longer-term (beyond a few months) impacts on decomposer microbial communities are poorly characterized and do not typically connect microbial communities to biogeochemistry, limiting our understanding of decomposer communities and their functions. The authors performed separate year-long human decomposition trials, one starting in spring, another in winter, integrating bacterial and fungal community structure and abundances with soil physicochemistry and biogeochemistry to identify key drivers of microbial community change. In both trials, soil acidification, elevated microbial respiration, and reduced soil oxygen concentrations occurred. Changes in soil oxygen concentrations were the primary driver of microbial succession and nitrogen transformation patterns, while fungal community diversity and abundance was related to soil pH. Relative abundance of facultative anaerobic taxa (Firmicutes and Saccharomycetes) increased during the period of reduced soil oxygen. The magnitude and timing of the decomposition responses were amplified during the spring trial relative to the winter, even when corrected for thermal inputs (accumulated degree days). Further, soil chemical parameters, microbial community structure, and fungal gene abundances remained altered at the end of 1 year, suggesting longer-term impacts on soil ecosystems beyond the initial pulse of decomposition products. (Published Abstract Provided)

Date Published: January 1, 2024