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

福克兰群岛是英国最大的海外领土，拥有地球上碳含量最高的土壤。泥炭地覆盖了几乎一半的土地面积，占英国管辖范围内泥炭总面积的10%。这些泥炭地在没有人类或食草哺乳动物的情况下发展了数千年。自250年前人类开始定居以来，大规模放牧和其他土地使用压力已经造成了深刻的生态变化。岛上约80%的独特的“tussac”，一种高大的泥炭形成的草，为包括企鹅和海狮在内的野生动物提供栖息地和庇护所，已经失去了放牧，泥炭侵蚀很普遍（图1）。然而，我们不知道福克兰群岛的泥炭地是否继续固碳（从而有助于减缓气候变化），或者人类活动是否已将这些巨大的碳储存转化为温室气体排放源。与位于福克兰群岛的南大西洋环境研究所（SAERI，CASE合作伙伴，他们为该项目提供了重要的直接商业支持;见支持信）和自然历史博物馆（NHM）作为CENTA 2 1级合作伙伴，该奖学金将提供一个独特的机会，以促进对这个特殊的，生态丰富但知之甚少的生态系统的科学认识。它将开创新局面，首次全面测量福克兰群岛天然和退化泥炭地的温室气体通量。尖端的地球化学和微生物分析，以及生境特征和使用地球观测数据的升级，将提供新的机制，这些通量的驱动因素的小规模的理解。研究结果将增强对这一重要生态系统的基本认识，这一生态系统接近泥炭形成的“气候包络线”边缘，因此可能有助于了解全球泥炭地对土地利用和气候变化的更广泛的脆弱性。该项目将通过量化福克兰群岛的温室气体排放量来产生政策和公众利益，支持联合王国和福克兰群岛政府实现其气候变化目标，并直接实际应用于制定福克兰群岛碳抵消计划。监督小组成员参与世界各地的泥炭地研究将确保该项目具有全球相关性和影响力。

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.