"Subsurface methane dynamics of fens: Biogeochemical controls on production, peat free-phase gas content and efflux"

“沼泽地下甲烷动态：对生产、泥炭游离相气体含量和流出的生物地球化学控制”

• 批准号: 342020-2012
• 负责人: Strack, Maria
• 金额: $ 0.35万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=549575
• 关键词: Subsurface; methane; dynamics; fens; Biogeochemical

Peatlands are important ecosystems in Canada, covering approximately 12% of the country's landmass. These ecosystems play an important role in the global carbon cycle, accounting for up to one third of global soil carbon stock and up to 10% of atmospheric emissions of the greenhouse gas methane (CH4). Despite this important role, spatial and temporal patterns of CH4 fluxes from peatlands are still fairly poorly described, likely because of the contribution of ebullition (release of bubbles) to total CH4 flux. If ebullition is important, this also suggests that bubbles (free-phase gas; FPG) are present within peat soil. Research over the past decade has indicated the presence and importance of FPG in Sphagnum-dominated peatlands; however, very little is known about FPG in more mineral rich peatlands and the relative importance of ebullition to total CH4 flux from these ecosystems. These mineral rich peatlands, fens, have a different vegetation community, and hence soil structure, suggesting that the rate of CH4 production, transport and trapping of FPG may be very different than Sphagnum-dominated peatlands. The proposed research program aims to address this gap in knowledge by 1) determining the stock of CH4 dissolved, and as FPG in several fen peatlands, 2) describing the spatial and temporal variation in the size of this stock, 3) evaluating the importance of ebullition to the total CH4 flux from these fens, and 4) evaluating potential controls on CH4 stock and ebullition.

泥炭地是加拿大重要的生态系统，约占全国陆地面积的12%。这些生态系统在全球碳循环中发挥着重要作用，占全球土壤碳储量的三分之一，占温室气体甲烷（CH 4）大气排放量的10%。尽管这一重要的作用，从泥炭地的CH 4通量的空间和时间模式仍然是相当差的描述，可能是因为沸腾（释放气泡）的贡献，总CH 4通量。如果沸腾是重要的，这也表明气泡（自由相气体; FPG）存在于泥炭土中。在过去的十年中的研究表明，在泥炭藓为主的泥炭地FPG的存在和重要性，但是，很少有人知道FPG在更多的矿物质丰富的泥炭地和沸腾的相对重要性，从这些生态系统的总CH 4通量。这些矿物质丰富的泥炭地，沼泽，有不同的植被群落，因此土壤结构，这表明甲烷的生产，运输和捕获的FPG的速率可能是非常不同的泥炭地为主。拟议的研究计划旨在解决这一知识的差距，1）确定股票的CH 4溶解，并作为FPG在几个沼泽泥炭地，2）描述的空间和时间变化的大小，这个股票，3）评估沸腾的重要性，从这些沼泽的总CH 4通量，和4）评估潜在的控制CH 4股票和沸腾。