Unveiling the Secrets of Peatlands for Climate Change Mtigation

苏格兰泥炭地(即沼泽地、沼泽地和沼泽地)覆盖了全国约20%的土地，土壤中储存了大约1.6亿吨碳，因此，在全新世时间尺度上代表着温室气体收支的一个重要组成部分(Froll king等人，2006年)。泥炭地在水质和供水方面也发挥着重要作用，拥有一系列独特的物种，提供娱乐空间，并保存过去环境和人类活动的记录(Bain等人，2011年)。然而，据估计，超过80%的苏格兰泥炭地正在退化(苏格兰土壤，2022)。未退化的泥炭地积累土壤有机质，并作为大气二氧化碳的汇生态系统，因为在淹水土壤条件下没有好氧分解和相关的二氧化碳排放(Dise，2009)。然而，由于土壤水分动态、氧化还原潜力、基质材料的可用性以及对水文和植被的人为改变，受管理的泥炭地(例如，排水和耕种或绿化)的温室气体排放在空间和时间水平上都表现出高度的变异性(Schrier-Uijl等人，2010年；Abdalla等人，2014；Abdalla等人，2016)。人们担心，退化的泥炭地可能通过从土壤中释放二氧化碳而显著加剧人为气候变化(Hooijer等人，2010年)。这一担忧目前正在推动苏格兰和世界各地保护和恢复泥炭地的广泛努力。一方面，恢复退化的泥炭地可以将它们重新连接到它们的集水区，从而减少二氧化碳排放，增加碳储存(Horsburgh等人，2022)。另一方面，与最初的管理前的CH4排放相比，通过重新润湿恢复的CH4排放增加了46%(Abdalla等人，2016年)。然而，恢复对温室气体净排放量(即温室气体排放量和碳储存之间的平衡)的影响仍然不清楚。该项目将使用实验数据、过程建模和荟萃分析，通过调查温室气体排放和碳储存来评估温室气体净排放量，以填补这一知识空白。此外，将温室气体排放归因于人为和自然驱动因素是一个巨大的挑战，是成功评估泥炭地减排潜力的先决条件。据我们所知，到目前为止，退化或恢复的苏格兰泥炭地对基线下的温室气体净排放量和气候变化的影响尚未完全量化/绘制，也没有建立潜在的恢复技术模型。这项研究将实现以下目标：1)创建苏格兰泥炭地年度温室气体净排放量基线地图；2)创建气候变化下泥炭地年度温室气体净排放量地图；3)绘制和调查排水/恢复对温室气体净排放量的影响；以及4)调查苏格兰泥炭地温室气体排放对人为和自然驱动因素的敏感性。

The Scottish peatlands (i.e. mires, fen and bog) cover about 20% of the country, storing approximately 1600 million tonnes of carbon in the soils, and therefore, represent an essential component of GHG budget at the Holocene time scale (Frolking et al., 2006). Peatlands also play important roles in water quality and supply, host a range of unique species, provide spaces for recreation and preserve a record of past environments and human activity (Bain et al., 2011). However, it is estimated that over 80% of the Scottish peatlands are degraded (Scotland soils, 2022). Un-degraded peatlands accumulate soil organic matter and act as a sink ecosystem for atmospheric CO2 due to the absence of aerobic decomposition and associated CO2 emissions under waterlogged soil conditions (Dise, 2009). Nevertheless, managed peatlands (e.g. drained and cultivated or afforested) show a high variability in GHG emissions at both spatial and temporal levels due to active systems in soil moisture dynamics, redox potential, availability of substrate materials and man-made alterations to hydrology and vegetation (Schrier-Uijl et al., 2010; Abdalla et al., 2014; Abdalla et al., 2016). There is a concern that degraded peatlands may significantly exacerbate anthropogenic climate change through release of CO2 from soils (Hooijer et al, 2010). This concern is currently motivating extensive attempts to conserve and restore peatlands in Scotland and around the world. On one hand, restoring degraded peatlands can reconnect them to their catchments and thereby, decreases CO2 emissions and increases carbon storage (Horsburgh et al., 2022). On the other hand, restoration by rewetting increases CH4 emissions (which has a higher radiative forcing than CO2) by 46% compared to the original pre-management CH4 emissions (Abdalla et al., 2016). However, it is still not clear how restoration affects net GHG emissions (i.e. balance between GHG emissions and carbon storage). This project will use experimental data, process modelling and meta-analyses to assess net GHG emissions by investigating both GHG emissions and carbon storage to fill this gap in knowledge. Further, the attribution of GHG emissions to anthropogenic and natural drivers is a great challenge, and is a prerequisite to successfully assess the potential to reduce the emissions from peatlands.To the best of our knowledge, until this date, the impact of degraded or restored Scottish peatlands on net GHG emissions under baseline and climate change are not fully quantified/ mapped, nor potential restoration techniques modelled. This study will achieve the following objectives:1) Create maps of baseline annual net GHG emissions from the Scottish peatlands; 2) Create maps of annual net GHG emissions from peatlands under climate change; 3) Map and investigate the impacts of drainage/ restoration on net GHG emissions; and 4) Investigate sensitivity of GHG emissions from the Scottish's peatlands to anthropogenic and natural drivers.