Collaborative Research: Coupled biological and photochemical degradation of dissolved organic carbon in the Arctic

合作研究：北极溶解有机碳的生物和光化学耦合降解

• 批准号: 1753731
• 负责人: George Kling
• 金额: $ 60.62万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1753731&HistoricalAwards=false
• 关键词: Collaborative; Research; Coupled; biological; photochemical

About half of the carbon that moves from land to streams, rivers, and lakes is lost to the atmosphere as carbon dioxide. Carbon from land is converted to CO2 mainly by microbial respiration and exposure to sunlight. Both processes happen in sunlit surface waters, but little is known about how they interact to produce CO2. For instance, previous research has shown that sunlight exposure can either increase or decrease microbial respiration. In addition, there is little known about how composition of microbial communities may influence microbial respiration. Understanding how microbes and sunlight interact is particularly important in the Arctic where thawing permafrost soils will release large amounts of carbon from land to water. Advancing our understanding of loss of this carbon to the atmosphere is critical to understanding the global carbon cycle. This project takes advantage of recent advances in microbial genomics and carbon chemistry to improve understanding of carbon cycling in Arctic freshwaters. This research will also engage high school teachers and students in scientific discovery and application. The PIs also plan to provide undergraduates with research opportunities through this project.Determining the controls on coupled photo-bio conversion of dissolved organic carbon (DOC) to CO2 is essential for understanding the drivers of CO2 fluxes to the atmosphere from inland waters in the Arctic. To gain this understanding, this project will use experiments to answer three questions: (Q1) How is microbial metabolism controlled by DOC chemistry? This question will be answered with incubations of microbial communities with DOC leached from surface soils and deeper permafrost soils from two dominant arctic landscapes. Microbial pathways of DOC conversion to CO2 will be identified by measuring microbial gene abundance and the expression of those genes, and molecular formulas of DOC that are consumed and produced during incubations identified by mass spectrometry; (Q2) How does DOC exposure to sunlight alter how microbes convert DOC to CO2? This question will be answered by exposing leached soil DOC to sunlight; (Q3) How does the longer-term adaptation of microbial communities affect the rate of DOC conversion to CO2? This question will be answered by measuring microbial abundance, respiration, production, and community composition (species) during the incubations. A detailed understanding of these processes is critical because conversion of permafrost soil carbon to CO2 has the potential to create a positive and accelerating feedback to atmospheric CO2 levels and resulting environmental changes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

大约一半从陆地进入溪流、河流和湖泊的碳以二氧化碳的形式散失在大气中。来自土地的碳主要通过微生物呼吸和阳光照射转化为二氧化碳。这两种过程都发生在阳光照射的地表水中，但人们对它们如何相互作用产生二氧化碳知之甚少。例如，先前的研究表明，阳光照射可以增加或减少微生物呼吸。此外，微生物群落的组成如何影响微生物呼吸作用还知之甚少。了解微生物和阳光如何相互作用在北极尤为重要，因为北极的永久冻土融化会将大量的碳从陆地释放到水中。推进我们对大气中碳流失的理解对于理解全球碳循环至关重要。该项目利用微生物基因组学和碳化学的最新进展来提高对北极淡水中碳循环的理解。这项研究还将吸引高中教师和学生参与科学发现和应用。pi还计划通过该项目为本科生提供研究机会。确定溶解有机碳（DOC）耦合光生物转化为二氧化碳的控制对于了解北极内陆水域向大气输送二氧化碳的驱动因素至关重要。为了了解这一点，本项目将通过实验来回答三个问题：（Q1）微生物代谢是如何被DOC化学控制的？这个问题将通过从两个主要的北极景观的表层土壤和深层永久冻土土壤中浸出DOC的微生物群落的孵育来回答。通过测量微生物基因丰度和基因表达来确定DOC转化为CO2的微生物途径，并通过质谱法确定培养过程中消耗和产生的DOC的分子式；（Q2） DOC暴露在阳光下如何改变微生物将DOC转化为二氧化碳的方式？这个问题的答案是将浸出的土壤DOC暴露在阳光下；（Q3）微生物群落的长期适应如何影响DOC转化为CO2的速率？这个问题将通过在孵育过程中测量微生物丰度、呼吸、产量和群落组成（物种）来回答。对这些过程的详细了解是至关重要的，因为永久冻土土壤碳向二氧化碳的转化有可能对大气二氧化碳水平产生积极和加速的反馈，从而导致环境变化。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Active Layer Groundwater Flow: The Interrelated Effects of Stratigraphy, Thaw, and Topography

• DOI: 10.1029/2018wr024636
• 发表时间: 2019-08
• 期刊: Water Resources Research
• 影响因子: 5.4
• 作者: Michael T. O'Connor;M. Cardenas;B. Neilson;K. Nicholaides;G. Kling

Empirical Models for Predicting Water and Heat Flow Properties of Permafrost Soils

• DOI: 10.1029/2020gl087646
• 发表时间: 2020-06
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: M. O'Connor;M. Cardenas;S. Ferencz;Yue Wu;B. Neilson;Jingyi Chen;G. Kling

Understanding the effects of climate change via disturbance on pristine arctic lakes—multitrophic level response and recovery to a 12‐yr, low‐level fertilization experiment

通过干扰了解气候变化对原始北极湖泊的影响——12 年低水平施肥实验的多营养水平响应和恢复

• DOI: 10.1002/lno.11893
• 发表时间: 2021
• 期刊: Limnology and Oceanography
• 影响因子: 4.5
• 作者: Budy, Phaedra;Pennock, Casey A.;Giblin, Anne E.;Luecke, Chris;White, Daniel L.;Kling, George W.
• 通讯作者: Kling, George W.

A distributed analysis of lateral inflows in an Alaskan Arctic watershed underlain by continuous permafrost

连续多年冻土下的阿拉斯加北极流域横向流入的分布式分析

• DOI: 10.1002/hyp.13611
• 发表时间: 2019
• 期刊: Hydrological Processes
• 影响因子: 3.2
• 作者: King, Tyler V.;Neilson, Bethany T.;Overbeck, Levi D.;Kane, Douglas L.
• 通讯作者: Kane, Douglas L.

Interannual, summer, and diel variability of CH 4 and CO 2 effluxes from Toolik Lake, Alaska, during the ice-free periods 2010–2015

2010 年至 2015 年无冰期阿拉斯加 Toolik 湖 CH 4 和 CO 2 流出量的年际、夏季和昼夜变化

• DOI: 10.1039/d0em00125b
• 发表时间: 2020
• 期刊: Environmental Science: Processes & Impacts
• 作者: Eugster, Werner;DelSontro, Tonya;Shaver, Gaius R.;Kling, George W.
• 通讯作者: Kling, George W.