Impact of peat mining and restoration on methane turnover potential and methane-cycling microorganisms in a northern bog

authored by
Max Reumer, Monika Harnisz, Hyo Jung Lee, Andreas Reim, Oliver Grunert, Anuliina Putkinen, Hannu Fritze, Paul L.E. Bodelier, Adrian Ho
Abstract

Ombrotrophic peatlands are a recognized global carbon reservoir. Without restoration and peat regrowth, harvested peatlands are dramatically altered, impairing their carbon sink function, with consequences for methane turnover. Previous studies determined the impact of commercial mining on the physicochemical properties of peat and the effects on methane turnover. However, the response of the underlying microbial communities catalyzing methane production and oxidation have so far received little attention. We hypothesize that with the return of Sphagnum spp. postharvest, methane turnover potential and the corresponding microbial communities will converge in a natural and restored peatland. To address our hypothesis, we determined the potential methane production and oxidation rates in natural (as a reference), actively mined, abandoned, and restored peatlands over two consecutive years. In all sites, the methanogenic and methanotrophic population sizes were enumerated using quantitative PCR (qPCR) assays targeting the mcrA and pmoA genes, respectively. Shifts in the community composition were determined using Illumina MiSeq sequencing of the mcrA gene and a pmoA-based terminal restriction fragment length polymorphism (t-RFLP) analysis, complemented by cloning and sequence analysis of the mmoX gene. Peat mining adversely affected methane turnover potential, but the rates recovered in the restored site. The recovery in potential activity was reflected in the methanogenic and methanotrophic abundances. However, the microbial community composition was altered, being more pronounced for the methanotrophs. Overall, we observed a lag between the recovery of the methanogenic/ methanotrophic activity and the return of the corresponding microbial communities, suggesting that a longer duration (> 15 years) is needed to reverse mining-induced effects on the methane-cycling microbial communities.

External Organisation(s)
Netherlands Institute of Ecology
University of Warmia and Mazury
Kunsan National University
Max Planck Institute for Terrestrial Microbiology (MPIterMic)
Ghent University
Natural Resources Institute Finland (Luke)
Type
Article
Journal
Applied and Environmental Microbiology
Volume
84
ISSN
0099-2240
Publication date
01.02.2018
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Biotechnology, Food Science, Applied Microbiology and Biotechnology, Ecology
Sustainable Development Goals
SDG 15 - Life on Land
Electronic version(s)
http://hdl.handle.net/20.500.11755/6225299b-89a8-4172-b520-4b990e4addf9 (Access: Open)
https://doi.org/10.1128/AEM.02218-17 (Access: Open)
http://europepmc.org/articles/pmc5772240 (Access: Open)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5772240 (Access: Open)