Processing and fluxes of DOM in peat-pools and lochans

泥炭地是英国最大的碳库，但由于土地管理不善，它们在很大程度上已经退化。再加上预测的极端天气事件(如干旱和野火)可能性的增加，意味着我们现在有大量的碳库，很容易通过向大气释放二氧化碳/甲烷或侵蚀并作为溶解有机碳(DOC)输送到水生连续体中而损失。河流网络只是将陆地衍生的溶解有机物质(DOM)输送到海洋的模式现在已经被彻底摒弃，河流和湖泊现在被认为是DOC分解和CO2/CH4向大气排放的生物地球化学热点。泥炭池和泥炭湖是DOM通过集水区进行水生加工的关键区域，但人们对DOM流入和流出这些系统或其内部分解背后的驱动因素知之甚少。这一博士学位将解决这一知识鸿沟，旨在加深我们对泥炭衍生DOM进入水生系统时的生物地球化学处理的理解。此外，量化光化学反应和生物化学降解在泥炭池处理DOM过程中的相对重要性将有助于我们理解它们如何应对干旱和野火等预计的环境压力增加。最后，将苏格兰北部泥炭池的这些速率和过程与环境联系起来，将开始扩大我们的知识，使我们了解这些水生系统对泥炭衍生的DOM退化的初始阶段有多么重要。

Peatlands are the UKs largest carbon store, yet they have been largely degraded by poor land management. Combined with predicted increased likelihood of extreme weather events (e.g. droughts and wildfire) means that we now have a large pool of carbon vulnerable to loss through release of CO2/CH4 to the atmosphere, or erosion and transport as Dissolved Organic Carbon (DOC) into the aquatic continuum. The paradigm that fluvial networks simply transport terrestrial derived Dissolved Organic Matter (DOM) to the ocean is now firmly dismissed, with rivers and lakes now recognised as biogeochemical hotspots for the breakdown of DOC and the outgassing of CO2/CH4 to the atmosphere. Peat-pools and lochans are key zones for the aquatic processing of DOM in its journey through the catchment, yet little is known about DOM fluxes into and out of these systems or the drivers behind decomposition within them. This PhD will address this knowledge gap, aiming to further our understanding of biogeochemical processing of peat-derived DOM as it enters the aquatic systems. Furthermore, quantifying the relative importance of photochemical reactions and biochemical degradation in the processing of DOM in peat-pools will aid our understanding of how they may respond to predicted increases of environmental stress such as drought and wildfires. Lastly, contextualising these rates and processes in the peat-pools of northern Scotland will begin to expand our knowledge of how important these aquatic systems are for the initial stages in degradation of peat-derived DOM.