The Hidden Half: Blanket Bog Microbial Communities across a Spectrum of Site and Management Conditions and Impacts on Peatland Carbon Cycling

Monitoring blanket bog condition and functions is critical in ensuring the ecosystem services they provide, especially as their environment becomes increasingly pressured. Microbial DNA-based monitoring tools allow the assessment of soil communities, but our knowledge of the microbial processes underpinning ecosystem service provision is limited. Specifically, (a) how microbial communities vary with management and climate, (b) how the microbial community is related to environmental variables, and (c) whether microbial community measurements can be used to predict water quality and carbon fluxes, including methane. Here, microbial community taxonomy and fungal community function was measured on UK blanket bog with different management, habitat, or restoration status using sequencing techniques, alongside a novel carbon partitioning mesocosm experiment. Water quality variables were measured alongside this experimental setup, along with a suite of environmental, chemical, and soil edaphic variables. Fungal, bacterial, and archaeal microbial communities changed with management and location. Microbial communities were highly variable but showed some categorisation based on climatic conditions. Communities subject to managed grouse moor burning were frequently different from every other habitat category. Concentrations of zinc, magnesium, and calcium were strongly associated with microbial community structure, alongside soil temperature, rainfall, and the abundance of Calluna vulgaris. Blanket bogs with a legacy of pollution contained specifically adapted microbial taxa. Grouse moor burning was linked to changes in fungal trophic groups, with potential consequences for water quality. Changes to the fungal and bacterial communities, alongside the abundance of sedges, were linked to changes in methane flux, and fungal community change was linked to soil respiration. The findings here indicate that ecosystem services can be linked to management and habitat status via microbial processes, but that our knowledge remains incomplete. This thesis provides the basis for further in-depth experiments and recommends focusing on a functional, rather than a taxonomy, based approach.