Sheep versus sea-lions? Quantifying human impacts on the carbon and greenhouse gas balance of peatlands in the Falkland Islands.

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The Falkland Islands are the largest of the UK's Overseas Territories, and hold some of the most carbon-rich soils on Earth. Peatlands cover almost half of the land area, and account for ~10% of the total peat area under UK jurisdiction. These peatlands developed over millenia in the absence of humans or herbivorous mammals. Since human settlement began 250 years ago, large-scale grazing and other land-use pressures have caused profound ecological changes. Around 80% of the Islands' distinctive 'tussac', a tall peat-forming grass which provides habitat and shelter for wildlife including penguins and sea-lions, has been lost to grazing, and peat erosion is widespread (Figure 1). However, we do not know whether Falkland peatlands continue to sequester carbon (thus contributing to climate change mitigation) or whether human activities have converted these vast carbon stores into GHG emission sources. Working with the Falkland-based South Atlantic Environment Research Institute (SAERI, CASE Partner, who are offering significant direct commercial support to the project; see Letter of Support) and the Natural History Museum (NHM) as a CENTA2 Level 1 partner, the studentship will offer a unique opportunity to advance scientific understanding of this exceptional, ecologically rich but poorly understood ecosystem. It will break new ground by making the first comprehensive measurements of greenhouse gas (GHG) fluxes from natural and degraded Falkland peatlands. Cutting-edge geochemical and microbiological analyses, and habitat characterisation and upscaling using Earth Observation data, will provide new mechanistic, landscape-scale understanding of the drivers of these fluxes. The results will enhance fundamental understanding of this important ecosystem, which is close to the edge of the 'climate envelope' for peat formation, and may therefore help to understand the wider vulnerability of global peatlands to land-use and climate change. The project will generate policy and public interest by quantifying the GHG emissions of the Falklands, support the UK and Falkland governments in meeting their climate change targets, and have direct practical application in the development of a Falkland carbon offsetting scheme. The involvement of members of the supervisory team in peatland research throughout the world will ensure that the project has global relevance and impact.