Peat carbon in the Earth system through time

加拿大拥有世界上很大一部分湿地。这些生态系统在全新世和更新世时期积累了大量的泥炭形式的碳库，也是数千年来甲烷的重要自然来源，甲烷是一种强有力的温室气体。因此，加拿大的湿地以复杂的方式影响全球碳循环，预计这种影响将随着气候变暖而改变。我的研究计划的首要目标是调查泥炭形成的湿地在全球碳气候系统中的作用，从而为加拿大提供关键的新信息，以应对缓解当前和未来气候变化的挑战。拟议的研究计划解决了湿地古生物地学中的一系列未决问题。第一个问题涉及温带湿地碳库的规模和重要性。就总的碳储量而言，高纬度和热带地区的泥炭地是最大的，而且量化得相对较好。由于人类活动的影响，温带湿地已经严重退化，由于湿地被转变为农业、城市或工业用地，造成了面积上的巨大损失。因此，这项研究将使用尖端的建模技术来预测在人类影响之前温带地区可能存在的古湿地。利用现有的和新的人工景观中残留湿地的现场数据，泥炭深度和碳含量的估计将与模拟的面积范围相结合，以产生对温带湿地碳库规模的第一次估计。第二个目标与“埋藏”池中泥炭碳的量化有关。虽然冰川侵蚀阻止了可追溯到更新世的古老泥炭地中广泛存在的泥炭碳，但在安大略省遥远的北部，由于独特的地理环境，3万年前的泥炭地被保存在冰川沉积之下。利用测年技术以及宏观和微观化石指标的研究，这项研究计划试图确定泥炭碳在那个时期积累的方式和原因。最后，这个项目试图调查后冰川时期安大略省火环和邻近的哈德逊湾低地泥炭地的净碳平衡。将从这些地区采集泥炭岩芯，用于分析隐形阿米巴(对地下水位深度敏感的微生物)和新的分子指示器，这些指示器将被整合，以确定随时间变化的气候和生态演替的碳吸收和释放速率。这些地区拥有广阔的泥炭地，可能会受到未来发展的影响。通过由学员开展的一系列项目，这项研究将为确定我们的湿地在全球碳循环和气候系统中的重要性提供关键信息。

Canada is home to a large portion of the world's wetlands. These ecosystems have accumulated vast pools of carbon in the form of peat over the Holocene and Pleistocene Epochs, and have also been important natural sources of methane, a potent greenhouse gas, for many thousands of years. Thus, Canada's wetlands affect the global carbon cycle in complex ways, and this is predicted to change with climate warming. The overarching goal of my research program is to investigate the role of peat-forming wetlands in the global carbon-climate system, thus providing Canada with critical new information to face the challenge of mitigating present and future climate change. The proposed research program addresses a series of open questions in wetland paleo-biogeoscience. The first concerns the size and importance of the temperate zone wetland carbon pool. Peatlands in high latitude and tropical regions are the largest in terms of overall carbon storage and are relatively well quantified. Temperate zone wetlands have been severely degraded by human impact, with massive losses in areal extent as wetlands have been converted to agricultural, urban or industrial land uses. Thus, this research will use cutting edge modelling techniques to predict where paleo-wetlands would have existed in temperate zone regions prior to human impact. Using available and new field data from remnant wetlands in anthropogenic landscapes, estimates for peat depth and carbon content will be combined with modelled areal extents to produce the first estimates of the size of the temperate wetland carbon pool. The second objective relates to the quantification of peat carbon in “buried” pools. While glacial erosion has prevented the persistence of widespread peat carbon from ancient peatlands dating to the Pleistocene, there are locations in Ontario's Far North where peatlands >30,000 years old are preserved underneath glacial deposits, owing to unique geographic settings. Using dating techniques, and the study of macro- and micro-fossil indicators, this research program seeks to determine how and why peat carbon accumulated at those times. Finally, this program seeks to investigate net carbon balance over the post-glacial period in peatlands of Ontario's Ring of Fire and adjacent Hudson Bay Lowlands. Peat cores will be collected from these regions for analysis of testate amoebae (micro-organisms sensitive to water table depth) and novel molecular indicators which will be integrated to determine rates of carbon uptake and release over time in response to shifting climates and ecological succession. These are regions with extensive peatlands which may be subject to future development. Through a series of projects to be carried out by student trainees, this research will provide critical information for determining the importance of our wetlands in global carbon cycling and in the climate system.