Biogeochemistry and ecohydrology of northern peatlands

加拿大和其他196个缔约方在《联合国气候变化框架公约》（UNFCC）巴黎第21次缔约方会议（COP 21）上承诺，将温室气体排放限制在与工业化前全球气温相比不超过2摄氏度的水平。这意味着大气中温室气体的增加不能超过约450至500 ppm的二氧化碳当量，2016年是二氧化碳浓度超过400 ppm的第一年！与cop21的大多数其他缔约方不同，加拿大在其活的植被和土壤中含有世界上不成比例的陆地碳。这对我们如何管理我们的碳景观有着巨大的影响，减少化石燃料的排放仅仅被土地利用变化或无意的生物圈反馈所取代是没有意义的。我的研究项目集中在加拿大和世界泥炭地最高密度的碳生态系统。***北部泥炭地占世界陆地面积的6%（约占加拿大的12%），含有500至700亿吨碳（加拿大泥炭地为150亿吨碳），每年排放40至50亿吨甲烷（占全球排放量的10%，占自然来源的20%）。然而，我们对泥炭地的认识以及泥炭地对环境变化的反应比几乎所有其他主要生态系统都要差得多。这是令人不安的，因为泥炭地已经被确定为生态系统，如果受到干扰，可能会导致地球系统的临界点。泥炭地是独特的，因为它们的结构和功能受到水文反馈的强烈调节。因此，它们是复杂的生态系统，它们对外部压力源的变化表现出一系列的弹性，但也可能发生灾难性的变化，超出其稳定的极限。我的研究项目的目标是了解泥炭地的复杂性，这样我们就可以预测对环境变化的敏感性。我的短期目标是进一步探索跨尺度的水文和生态系统过程和模式之间的反馈，因为它们是泥炭地稳定性的一个新兴特性；研究由于远距离运输和土地利用变化以及气候变化而投入增加的营养物如何影响其碳循环和与大气的碳交换；提高我们模拟泥炭地生物地球化学过程的能力。***我将通过实证研究和理论研究相结合来实现我的目标，并应用知识的进步来提高我们预测未来环境变化对泥炭地的影响的能力，以及泥炭地变化对地球系统的影响。通过这个研究项目，我将在生物地球化学和生态水文学交叉的生物地球科学领域培养几名本科生、一名硕士和五名博士。他们将学习成为独立的科学家，为他们在学术界、政府和/或私营部门的研究事业做准备。

Canada, along with 196 other parties, committed at the United National Framework Convention of Climate Change (UNFCC) Paris' 21st Conference of Parties (COP 21) to limit greenhouse gas emissions (GHGs) to levels that would achieve no more than 2oC increase from pre-industrial global temperature. This means the increase in GHGs in the atmosphere cannot exceed ~450 to 500 ppm CO2 equivalents 2016 is the first year that CO2 concentrations will exceeded 400 ppm! Unlike most of the other parties to COP 21, Canada contains a disproportionate amount of the world's terrestrial carbon in its living vegetation and soils. This has huge implications for how we manage our carbon landscape it makes no sense to reduce fossil fuel emissions to have them only replaced by emissions from land-use change or inadvertent biospheric feedbacks. My research program focusses on the highest density carbon ecosystem in Canada and the world peatlands. *** Northern peatlands cover ~ 6% of the world's land area (~12% of Canada), contain somewhere between 500 and 700 Gt C (150 Gt C in Canadian peatlands), and annually emit 40 to 50 Tg of methane (10% of global emissions and > 20% of natural sources). Yet our outstanding of peatlands and how they might respond to environmental change is much poorer than almost all other major ecosystems. This is troubling as peatlands have been identified as ecosystems that, if disturbed, could be contribute to tipping points in the Earth System. Peatlands are unique because their structure and function is strongly regulated by hydrological feedbacks. Hence, they are complex ecosystems they show a range of resilience to changes in external stressors but can change catastrophically beyond their limits of stability. *** My research program's objectives are to understand the complexity of peatlands so we can project the sensitivity to environmental change. My short-term objectives are to further explore the feedbacks between the hydrology and ecosystem processes and patterns across scales because they are an emergent property of peatland's stability; to examine how nutrients whose input is increasing due to long range transport and land-use change, along with climate change, influence their carbon cycle and carbon exchanges with the atmosphere; and to improve our ability to simulate peatlands biogeochemical processes. *** I will attain my objectives through a combination of empirical and theoretical studies and apply the advances in knowledge to improving our ability to project the consequences of future environmental change on peatlands, and the consequences of changes in peatlands on the earth system. Through this research program I will train several undergraduates, a M.Sc. and five PhDs in the interdisciplinary biogeosciences of biogeochemistry and ecohydrology. They will learn to become independent scientists preparing them for research careers in the academia, government and/or the private sector.