Managing Peatlands as Carbon Stores

将泥炭地作为碳库进行管理

• 批准号: NE/H018751/1
• 负责人: Pippa Chapman
• 金额: $ 8.83万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Training Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FH018751%2F1
• 关键词: Managing; Peatlands; Carbon; Stores

Peatlands comprise a large accumulation of terrestrial organic matter, fixed from the atmosphere by photosynthesis, and are, therefore, important carbon stores. However, many peatlands in the UK have suffered from disturbance, including drainage, agricultural improvement, peat cutting, afforestation, burning, and increased atmospheric nutrient deposition. Such disturbance has altered peatland carbon cycling processes and has led to increased release of the soil carbon stock to the atmosphere. Therefore, protection and restoration of these degraded peatlands is being pursued by national and regional agencies in order to conserve existing carbon stocks (to help mitigate climate change), and to protect wildlife habitats and landscapes. Restoration usually involves blocking of drainage ditches to raise the water table and hence encourage waterlogged conditions that will enable peat to form again. It is believed that restoration reduces carbon losses both to the atmosphere and the aqueous environment. However, it may lead to an increase in methane (CH4) emissions, at least in the short term, which is a more potent greenhouse gas than carbon dioxide (CO2). Increases in CH4 emissions may reduce or even outweigh carbon savings associated with peatland restoration, when the carbon balance of a peatland is expressed in terms of global warming potential (GWP). Although there is some evidence that restored peatlands emit much less CO2 than degraded peatlands, there is considerable uncertainty over whether or not restored peatlands become carbon sinks in GWP terms because they are thought to emit more CH4. In addition, aqueous fluxes of carbon from peatlands are rarely, if ever, considered as part of the peatland carbon budget. Quantification of aqueous carbon loss, in addition to gaseous carbon losses, from peatlands is, therefore, critical in determining carbon budgets for sites, and in understanding the potential of restoration to reduce carbon losses and green house gas (GHG) flux. This project will address this knowledge gap by investigating how restoration affects the carbon sink function of ombrotrophic bogs. The research will take place at Thorne and Hatfield Moors, where existing restoration schemes, monitoring programmes, data sets, and management and academic help from Natural England are available. In particular the research will (i) investigate the impact of (a) water table height, (b) sedges and (c) time since restoration on CH4 emissions and GWP and (ii) elucidate the processes and factors that account for the high rates of CH4 emitted from blocked drainage ditches. The project will deliver new insights into how restoration practices influence the carbon budget and GWP of peatlands and the results will be used to improve UK and international policy and guidelines on peatland restoration and management for climate mitigation. It will provide an excellent package for student training, incorporating elements of field and laboratory work, enabling the development of a broad technical skills base, and peatland management. The inter-disciplinary nature of this project will provide the student with skills that will be of great value to their future scientific career. The fieldwork will build on an existing soil and soil water monitoring programme installed as part of a previous PhD project supervised by Chapman. Therefore, we are confident that the project is suitable for PhD study and that our expectations of the student are appropriate. Chapman and Baird have an excellent track record of PhD supervision and project completion, with students going on to successful post-PhD careers. The partnership between Leeds and the CASE partner, Natural England, will provide strength and depth across the inter-disciplinary topics of the project, in particular, peatland ecology, hydrology, soil science, carbon cycling and peatland management.

泥炭地包括大量积累的陆地有机物质，通过光合作用从大气中固定下来，因此是重要的碳储存。然而，英国的许多泥炭地都遭受了干扰，包括排水，农业改良，泥炭切割，植树造林，燃烧和增加大气养分沉积。这种干扰改变了泥炭地的碳循环过程，导致土壤碳储存向大气的释放增加。因此，国家和区域机构正在努力保护和恢复这些退化的泥炭地，以保护现有的碳储存（帮助缓解气候变化），并保护野生动物栖息地和景观。恢复通常包括堵塞排水沟，以提高地下水位，从而促进积水条件，使泥炭再次形成。据信，恢复减少了向大气和水环境的碳损失。然而，它可能导致甲烷（CH4）排放量的增加，至少在短期内是这样，甲烷是一种比二氧化碳（CO2）更强的温室气体。当泥炭地的碳平衡以全球升温潜能值表示时，甲烷排放量的增加可能会减少甚至超过与泥炭地恢复相关的碳节省。虽然有一些证据表明，恢复的泥炭地排放的CO2比退化的泥炭地少得多，但就全球升温潜能值而言，恢复的泥炭地是否成为碳汇存在很大的不确定性，因为它们被认为排放更多的CH4。此外，从泥炭地的碳水通量很少，如果有的话，被认为是泥炭地碳预算的一部分。因此，量化泥炭地的水溶性碳损失以及气态碳损失，对于确定碳预算以及了解恢复以减少碳损失和绿色温室气体（GHG）通量的潜力至关重要。该项目将通过调查恢复如何影响湿地沼泽的碳汇功能来解决这一知识差距。这项研究将在索恩和哈特菲尔德沼泽地进行，那里现有的恢复计划，监测计划，数据集，以及来自自然英格兰的管理和学术帮助。特别是，研究将（一）调查（a）地下水位高度、（B）莎草和（c）恢复后的时间对甲烷排放量和全球升温潜能值的影响，（二）阐明堵塞的排水沟排放甲烷的过程和因素。该项目将提供关于恢复实践如何影响泥炭地碳预算和GWP的新见解，其结果将用于改善英国和国际泥炭地恢复和管理的政策和指导方针，以减缓气候变化。它将为学生培训提供一个很好的一揽子计划，包括实地和实验室工作的要素，使广泛的技术技能基础和泥炭地管理的发展成为可能。该项目的跨学科性质将为学生提供对他们未来的科学生涯具有重要价值的技能。该实地工作将建立在现有的土壤和土壤水监测方案安装的一部分，以前的博士项目监督查普曼。因此，我们相信该项目适合博士研究，我们对学生的期望是适当的。查普曼和贝尔德有博士监督和项目完成的良好记录，与学生继续成功的博士后的职业生涯。利兹与CASE合作伙伴Natural England之间的合作关系将为该项目的跨学科主题提供力量和深度，特别是泥炭地生态学，水文学，土壤科学，碳循环和泥炭地管理。