Blanket peatland carbon dynamics: palaeoenvironmental contributions to the land use debate

Blanket peatlands are the most efficient UK terrestrial habitat for carbon storage and their protection is essential to meet greenhouse gas reduction targets. ‘Carbon conscious’ management seeks to manage the ecosystem specifically to maintain or enhance future carbon sequestration. Uncertainty over the impact of land use on blanket peatland carbon sequestration hampers attempts to manage the ecosystem in a sustainable manner. This thesis addresses both the poor understanding of the relationship between land use and carbon accumulation and the lack of palaeoenvironmental records which assess the integrity of Welsh blanket peatlands.A suite of dating techniques are used to reconstruct carbon accumulation rates across a range of peatlands. Data are combined with plant macrofossil results to offer insight into how land use has affected peatland development. Reported results emphasize that management cannot be considered a constant, linear forcing on blanket peatland development. An alternative method for examining the impacts of land management is presented, namely focussing on the cumulative expression of land management as manifested in vegetation records. Results suggest Sphagnum-dominated sites exhibit the most favourable conditions for carbon accumulation and the expansion of Molinia caerulea should be of concern to a carbon conscious peatland manager. Future directions for research are also discussed in light of the demonstrated fixation of the land use debate on comparatively recent anthropogenic impacts (i.e. post-AD 1850)