Impacts of recent anthropogenic changes on peatland carbon dynamics

泥炭地的重要性 * 泥炭地是湿地中最具代表性的一组。它们的总面积估计超过4亿平方公里，占地球表面的3-4%。超过90%的泥炭地位于北方半球（北方和亚北极）的温带和寒带，那里凉爽和潮湿的条件有利于降低有机物分解的速率。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，有助于保持水的数量和质量。它们在气候调节中也发挥着重要作用，因为它们构成了重要的碳汇，储存了地球土壤中超过40%的碳。国际组织最近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年）的主要声明之一是，陆地碳汇的减少是未来气候变化的主要风险之一。 ** 在大气碳循环中的作用 * 目前对最近变暖引起的土壤碳变化的方向或幅度没有共识。随着地表温度的上升，最近的一些研究模拟了碳向大气的净损失，而另一些研究则表明生物生产力的上升，因此更多的碳吸收与更长的生长季节有关。考虑到加拿大东部泥炭地的自然和受损状况，并遵循为魁北克省可持续发展、环境和气候变化防治部编写的关于魁北克省泥炭地碳储存量的综合报告，拟议的五年计划的目标是记录最近（比较了不同生物气候区土壤有机碳的动态，并对自然和人为压力引起的变化进行了分析。人类活动导致的碳储量和碳积累的变化（例如。排放量）将与可能抵消人为温室气体排放影响的生物量生产力的潜在增加进行比较。

Importance of peatlands***Peatlands 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 cycle***There 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.