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.

大约一半的碳从陆地到溪流，河流和湖泊移动的碳被以二氧化碳而丢失到大气中。来自土地的碳主要是通过微生物呼吸和暴露于阳光的。这两个过程都发生在阳光地表水中，但对它们如何相互作用以产生二氧化碳而知之甚少。 例如，先前的研究表明，阳光暴露可以增加或减少微生物呼吸。此外，关于微生物群落的组成如何影响微生物呼吸，鲜为人知。 了解微生物和阳光如何相互作用在北极中尤为重要，在北极，融化的多年冻土土壤将从土地到水中释放大量碳。促进我们对这种碳流失到大气的理解对于理解全球碳循环至关重要。 该项目利用了微生物基因组学和碳化学的最新进展，以提高对北极淡水中碳循环的了解。这项研究还将吸引高中教师和学生参与科学发现和应用。 PIS还计划通过该项目为大学生提供研究机会。确定对溶解有机碳（DOC）耦合的光生物转换为CO2的控制措施对于理解北极北水域内陆水域的二氧化碳驱动器到大气的驱动因素至关重要。为了获得这种理解，该项目将使用实验回答三个问题：（Q1）如何由DOC化学控制微生物代谢？ 这个问题将通过微生物群落与从表面土壤中浸出的DOC和从两个主要北极景观的深层土壤中浸出的DOC进行回答。 DOC转换为CO2的微生物途径将通过测量微生物基因丰度和这些基因的表达来鉴定，以及在通过质谱识别的孵育期间消耗和生产的DOC的分子公式； （Q2）DOC暴露于Sunlight如何改变Microbes将DOC转换为CO2的方式？ 这个问题将通过将浸出的土壤文档暴露在阳光下来回答； （Q3）微生物群落的长期适应如何影响DOC转换为CO2？ 在孵化过程中，将通过测量微生物丰度，呼吸，生产和社区组成（物种）来回答这个问题。对这些过程的详细理解至关重要，因为将永久冻土土壤碳转换为CO2有可能产生积极而加速的反馈大气二氧化碳水平并导致的环境变化。该奖项反映了NSF的法定任务，并认为通过使用基金会的知识和更广泛的影响来通过评估来审查CRITERIA，并被视为值得通过评估的支持。

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.

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.

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.