This project will adopt a range of multidisciplinary techniques to establish the composition, activity and drivers of greenhouse gas cycling microbiota within diffusion and ebullition CH4 release peat target sites, at damaged peat sites, and at peat restoration project sites in Scotland.
1) Greenhouse gas flux measurements:
In-situ measurements of greenhouse gas flux at a range of diffusion, ebullition, damaged and restored target sites in Scotland will be performed by constructing and deploying a network of CH4 and CO2 sensors. These will provide key information on the overall carbon budgets of each target site.
2) Greenhouse gas composition and redox potential profiles:
Gas diffusion probes and pore water sampling will be performed to determine the spatial variability of CH4 and CO2 concentrations down depth profiles and at different diffusion, ebullition, damaged and restored target sites. The redox potential of each of these sites will additionally be measured to profile the potential for biogeochemical activity.
3) Microbial composition and functional potential profiles:
Community profiles of both total and active microbiota will be profiled using rRNA gene amplicon sequencing. Profiles will be compared along depth transects and between different sites, and they will be correlated to physicochemical measurements to consider the environmental drivers of community form and function. Quantification of genes essential for methane oxidation (e.g. pmoA and mmoX) and methanogenesis (e.g. mcrA) will be profiled as indicators of the spatial variability of carbon cycling activity.
4) Link carbon cycling activity to microbiota:
To directly link microbial greenhouse gas production and cycling to individual organisms, stable isotope probing will be performed on aerobic and anaerobic microcosms using peat depth profiles from each target site. Active methanogens and methanotrophs will be isolated using 13C-labelled 13CH4 and 13CO2, and they will be profiled using 16S rRNA gene sequencing.
5) Impact analysis:
The potential impact of peatland damage to the microbial ecology of these systems will be considered though comparative statistical analyses of healthy and damaged systems. Microbial composition, abundance and activity will be considered alongside measured physicochemical conditions. The effectiveness of peatland restoration projects to restore the microbial ecology to its presumed original state will be considered and reported on through healthy, damaged and restored site comparisons.