The interaction induced response next to changes in activity and community composition provide a comprehensive understanding of the resilience of the microorganisms after peat mining
Ombrotrophic peatlands are a recognized global carbon reservoir and peat remains and will be the most important constituent in horticulture. Without restoration and peat regrowth, harvested peatlands are dramatically altered, impairing their carbon sink function, with consequences for methane turnover. This study determined the response of the underlying microbial communities catalyzing methane production and oxidation. 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. We determined the potential methane production and oxidation rates in natural, actively mined, abandoned, and restored peatlands over two consecutive years. In all sites, the methanogenic and methanotrophic population sizes were enumerated using quantitative PCR assays targeting the mcrA and pmoA genes, respectively. Peat mining adversely affected methane turnover potential, but the rates recovered in the restored site. In addition, little is known of the response and recovery of the methanotrophic interactome to disturbances. In a follow-up study, we determined the recovery of the methanotrophic interactome as inferred by a co-occurrence network analysis comparing a pristine and restored peatland. We coupled a DNA-based stable isotope probing (SIP) approach using [13C]CH4 to a co-occurrence network analysis derived from the 13C-enriched 16S rRNA gene sequences to relate the response in methanotrophic activity to the structuring of the interaction network. Bacterial community composition was distinct in both peatlands. Likewise, the methanotrophic interactome was profoundly altered in the restored peatland. Structuring of the interaction network after peat mining resulted in the loss of complexity and modularity, indicating a less connected and efficient network, which may have consequences in the event of recurring/future disturbances. Therefore, determining the response of the methane-driven interaction network, in addition to relating methanotrophic activity to community composition/abundances, provided a more comprehensive understanding of the resilience of the methanotrophs.
Grunert, O., Kaupper, T., Harnisz, M., Horn, M.A. and Ho, A. (2021). The interaction induced response next to changes in activity and community composition provide a comprehensive understanding of the resilience of the microorganisms after peat mining. Acta Hortic. 1317, 359-368
Sphagnum, methanogenesis, methane oxidation, nitrogen fixation, land-use change, nifH