Breaking down the permafrost carbon feedback enigma: characterizing the composition and lability of dissolved organic carbon (DOC) according to size fractions

破解永久冻土碳反馈之谜：根据尺寸分数表征溶解有机碳（DOC）的组成和稳定性

• 批准号: RTI-2018-00417
• 负责人: Lafreniere, Melissa
• 金额: $ 6.83万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=642268
• 关键词: Breaking; down; permafrost; carbon; feedback

We are requesting funding to acquire three integral components of a system to quantify the size distribution and elemental composition of dissolved organic matter (DOM) in Arctic watersheds. Permafrost soils represent a large store of soil organic matter (SOM), which represents a potential source of atmospheric carbon (CO2 and CH4) that could result in a positive feedback on climate warming if this organic matter is subject to decomposition. Climate warming is increasing the physical disturbance and thaw of permafrost, which is exposing previously buried and frozen pools of SOM, leading to mobilization and transport of this source of organic carbon as DOM in Arctic watersheds. It is well known that the bioavailability and toxicity of many metals and contaminants, and the biodegradability of DOM is related to its size. Yet very little is known about the distribution, composition or reactivity of different size fractions of DOM across the Canadian Arctic. This lack of knowledge is a critical gap, that limits our ability to assess the potential impact of permafrost degradation on both the permafrost carbon feedback and contaminant transport in permafrost watersheds.

我们要求资金以获取系统的三个积分组件，以量化北极流域中溶解有机物（DOM）的尺寸分布和元素组成。多年冻土土壤代表了大量的土壤有机物（SOM），它代表了大气碳（CO2和CH4）的潜在来源，如果这种有机物是分解的，则可能导致对气候变暖的积极反馈。气候变暖正在增加多年冻土的身体障碍和融化，后者正在暴露先前埋葬和冷冻的SOM池，从而导致这种有机碳作为DOM作为北极流域中的DOM的动员和运输。众所周知，许多金属和污染物的生物利用度和毒性以及DOM的生物降解性与其大小有关。然而，关于DOM在加拿大北极地区不同大小的分数的分布，组成或反应性知之甚少。缺乏知识是一个关键的差距，它限制了我们评估多年冻土碳反馈和多年冻土流域污染物转运的潜在影响的能力。