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，拥有地球上一些最富含碳的土壤。泥炭地覆盖了几乎一半的土地面积，约占英国管辖范围内泥炭总面积的10%。在没有人类或食草哺乳动物的情况下，这些泥炭地经过了数千年的发展。自250年前人类开始定居以来，大规模放牧和其他土地利用压力导致了深刻的生态变化。该群岛约80%的独特‘tussac’，一种高大的泥炭形成草，为包括企鹅和海狮在内的野生动物提供栖息地和庇护所，已因放牧而丧失，泥炭侵蚀很普遍(图1)。然而，我们不知道福克兰泥炭地是否继续封存碳(从而有助于减缓气候变化)，也不知道人类活动是否将这些巨大的碳库转化为温室气体排放源。与位于福克兰的南大西洋环境研究所(SAERI，CASE合作伙伴)和自然历史博物馆(NHM)作为CENTA2一级合作伙伴合作，该项目将提供一个独特的机会，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理解。它将首次对自然和退化的福克兰泥炭地的温室气体(GHG)通量进行全面测量，从而开辟新的天地。尖端的地球化学和微生物学分析，以及利用地球观测数据确定栖息地特征和扩大规模，将提供对这些通量驱动因素的新的机械和景观规模的理解。研究结果将加强对这一重要生态系统的基本了解，该生态系统接近泥炭形成的“气候包络”的边缘，因此可能有助于理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引起政策和公众的兴趣，支持英国和福克兰政府实现其气候变化目标，并在制定福克兰碳抵消计划方面具有直接的实际应用。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。

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.