Total organic carbon (TOC) analyzer for characterizing carbon, mercury, and microbial dynamics across peatland and forest ecosystems

总有机碳 (TOC) 分析仪，用于表征泥炭地和森林生态系统中的碳、汞和微生物动态

• 批准号: 344991-2007
• 负责人: Basiliko, Nathan
• 金额: $ 2.22万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments - Category 1 (<$150,000)
• 财政年份: 2006
• 资助国家: 加拿大
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=325822
• 关键词: Total; organic; carbon; TOC; analyzer

The patterned forest and peatland boreal and sub-boreal regions of Canada are exceptionally important because they store vast amounts of atmospheric carbon dioxide as organic matter in soils that otherwise would contribute to global warming, contain a large volume of the world's potable freshwater, and support forestry and peat natural resource industries. Links between soil carbon (C), greenhouse gas dynamics, ecosystem management, and water quality are inextricable in these ecosystems. Slow, incomplete decomposition of recalcitrant plant material by soil microorganisms, particularly under flooded or wet conditions, results in the production of dissolved organic carbon (DOC) that represents significant and often unaccounted C losses from ecosystems and serve as a biogeochemical link between peatland, upland, and aquatic systems throughout catchments. Methylmercury (MeHg) is an important pollutant in these ecosystems with environmental and human health consequences. In anaerobic wetland soils and aquatic environments where DOC production is greatest, Hg is methlyated through anaerobic microbial activity. Recent evidence has suggested that DOC is an important vector for transporting Hg to specific locations of methylation and binding with DOC may further increase bioavailability. It is becoming clear that in order to understand transport and biomagnification of Hg, we must characterize DOC dynamics throughout watersheds. We are requesting funds for a total organic C analyzer for DOC characterization that will allow us to measure rates of soil decomposition processes, C transfer across northern Canadian forest and wetland ecosystems that are important for Hg transport, and C substrate bioavailability to, and biomass of, soil microbial communities that are responsible for mineralization of organic matter and release of greenhouse gasses from these ecosystems.

加拿大北部和亚北部地区的花纹森林和泥炭地格外重要，因为它们将大量大气二氧化碳作为有机物质储存在土壤中，否则将导致全球变暖，蕴藏着世界上大量的饮用水淡水，并支持林业和泥炭自然资源产业。在这些生态系统中，土壤碳(C)、温室气体动态、生态系统管理和水质之间的联系是密不可分的。土壤微生物对顽固植物材料的缓慢、不完全分解，特别是在洪水或潮湿条件下，会导致溶解有机碳(DOC)的产生，这代表着生态系统中大量且往往无法解释的碳损失，并在整个集水区的泥炭地、高地和水生系统之间起着生物地球化学联系。甲基汞(MeHg)是这些生态系统中的一种重要污染物，对环境和人类健康造成影响。在DOC产生量最大的厌氧湿地土壤和水生环境中，汞通过厌氧微生物活动进行甲基化。最近的证据表明，DOC是将汞运输到特定甲基化位置的重要载体，与DOC结合可能进一步提高生物利用度。越来越清楚的是，为了了解汞的运输和生物放大作用，我们必须表征整个流域的DOC动态。我们正在申请用于DOC表征的总有机碳分析仪的资金，该分析仪将使我们能够测量土壤分解过程的速率、加拿大北部森林和湿地生态系统中对汞运输至关重要的C转移，以及负责有机质矿化和这些生态系统温室气体排放的土壤微生物群落的C底物生物有效性和生物量。