Impacts of recent anthropogenic changes on peatland carbon dynamics

泥炭地的重要性泥炭地是最广泛的一类湿地。据估计，它们的总面积超过4亿平方公里，占地球表面的3-4%。超过90%的泥炭地位于北半球(北半球和亚北极)的温带和寒带，那里凉爽潮湿的条件有利于有机物分解速度的降低。泥炭地为社会提供重要的生态系统服务。它们在全球水文循环中发挥着重要作用，有助于维持水量和水质。它们还在气候调节中发挥着重要作用，因为它们构成了重要的碳汇，储存了地球上土壤总碳的40%。国际组织最近已经认识到泥炭地生态系统在气候衰减中的作用，最近在罗马举行的全球土壤有机碳研讨会(2017)的主要声明之一是，陆地碳汇的减少是未来气候变化的关键风险之一。在大气碳循环中的作用目前，对于最近气候变暖导致的土壤碳变化的方向和程度还没有达成共识。随着地表温度的上升，最近的一些研究模拟了大气中碳的净损失，而另一些研究则表明，生物生产力的提高，因此更多的碳吸收与较长的生长季节有关。考虑到加拿大东部泥炭地的自然和破坏条件，并在为魁北克省可持续发展研究组织、魁北克环境与气候变化研究中心编制的关于量化魁北克省泥炭地碳储量的综合报告之后，拟议的五年计划的目标是记录这些不同生物气候区土壤有机碳动态的最新比较，并区分自然和人为压力造成的变化。人类活动引起的碳储量和碳积累的变化(例如将与生物质生产率的潜在增长进行比较，后者可能抵消人为温室气体排放的影响。

Importance of peatlandsPeatlands are the most widespead group of wetlands. Their total extent has been estimated to more than 400 million km2 which represents 3-4% of the earth's surface. More than 90% of peatlands are located in the temperate and cold belt in the Northern Hemisphere (boreal and subarctic) where cool and moist conditions favor decreased rate of organic matter decomposition. Peatlands provide important ecosystem services to society. They play an important role in the global hydrological cycle helping maintain both water quantity and quality. They also play a significant role in climate regulation as they constitute important carbon sinks by storing > 40% of the total carbon in soils over the planet. International organizations have recently recognized the role of peatland ecosystems in climate attenuation and one of the major statement from the recent Global Symposium on Soil Organic Carbon in Rome (2017) has been that reduction of terrestrial carbon sink represents one of the key risk for future climate change. Role in the atmospheric carbon cycleThere is currently no consensus on the direction or magnitude of the recent warming-induced changes on soil carbon. With rising surface temperatures, some recent studies have simulated a net loss of carbon to the atmosphere while some others suggest a rise of biological productivity, hence more carbon uptake linked with longer growing-seasons. Taking into account the natural and damaged conditions of peatlands in eastern Canada and following a synthesis produced for the Ministère du Développement Durable, de l'Environnement et de la Lutte contre les Changements Climatiques (MDDELCC), Québec on the quantification of peatlands carbon stocks in the Quebec province, the objectives of the proposed five years program aim to document the recent (comparison of soil organic carbon dynamics in these different bioclimatic regions and distangle the changes due to natural and anthropogenic pressures. Changes in carbon stocks and carbon accumulation due to human activities (ex. drainage) will be compared with the potential increase in biomass productivity that could potentially offset the impact of anthropogenic greenhouse gas emissions.