Collaborative Research: Permafrost climate feedbacks: How interactions among plants, microbes, and minerals affect biogeochemical projections in a changing Arctic

合作研究：永久冻土气候反馈：植物、微生物和矿物质之间的相互作用如何影响不断变化的北极的生物地球化学预测

• 批准号: 2031072
• 负责人: Caitlin Hicks Pries
• 金额: $ 32.08万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2031072&HistoricalAwards=false
• 关键词: Collaborative; Research; Permafrost; climate; feedbacks

The Arctic is warming at a rate faster than elsewhere on Earth, resulting in changes to Arctic ecosystems that may affect global climate. Permafrost is ground that remains frozen for at least two consecutive years. It occurs under approximately one fourth of the northern hemisphere's land surface and contain as much carbon as the entire atmosphere. Permafrost thaw leads to changes in the dominant vegetation and makes the carbon stored in the permafrost soil vulnerable to decomposition, but existing measurements and models disagree about the implications of these changes for the global carbon cycle. This research project investigates how processes mediated by microbes, minerals, and their interactions with vegetation affect the vulnerability of carbon in permafrost soils. The researchers are carrying out laboratory and growth chamber studies to investigate microbial communities and the transformations of carbon with permafrost thaw. They are incorporating the results of those studies into Earth system models to understand feedbacks to the climate system. This research is addressing critical knowledge gaps about how carbon stored in frozen permafrost will affect the Earth's carbon cycle, which is information urgently needed to inform climate change adaptation and mitigation strategies.This project is addressing the question: how will feedbacks between plants and soils (specifically minerals and microbes) affect arctic soil carbon balance in response to global change? Using state-of-the-science tools, such as microbial sequencing and stable isotope tracing, the researchers are carrying out (1) laboratory incubations to determine how soil microbial communities and mineralogy affect the fate of plant exudates and the vulnerability of native soil organic matter in thawed permafrost, and (2) plant-soil growth chamber mesocosms to trace belowground plant deposits into permafrost soils under ambient and elevated CO2. These findings are being used to develop and evaluate a microbial-enabled model that can handle the complexity of plant-microbe-mineral feedbacks. This soil model is being integrated into the Community Land Model (CLM) to predict the impact of permafrost thaw on the arctic carbon budget. This research enables better long-term projections of permafrost-climate feedbacks. The project is training the next generation of interdisciplinary Arctic scholars well-versed in scales ranging from microbial genes to global elemental cycles through PhD assistantships, postdoctoral research, and undergraduate laboratory education. In addition, the project provides training for up to 50 early career researchers on the theory and practice of land modeling, with a special focus on Arctic systems.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.

北极变暖的速度比地球上其他地方更快，导致北极生态系统发生变化，可能影响全球气候。永久冻土是指至少连续两年保持冻结状态的地面。它位于北方大约四分之一的陆地表面之下，所含碳量相当于整个大气层。 多年冻土融化导致主要植被的变化，使储存在多年冻土中的碳容易分解，但现有的测量和模型不同意这些变化对全球碳循环的影响。 该研究项目调查了微生物，矿物质及其与植被的相互作用如何影响永久冻土中碳的脆弱性。 研究人员正在进行实验室和生长室研究，以调查微生物群落和碳随冻土融化的转化。他们正在将这些研究的结果纳入地球系统模型，以了解对气候系统的反馈。这项研究正在解决关于冻结的永久冻土中储存的碳如何影响地球碳循环的关键知识空白，这是为气候变化适应和减缓战略提供信息所迫切需要的信息。该项目正在解决的问题是：植物和土壤（特别是矿物和微生物）之间的反馈如何影响北极土壤碳平衡以应对全球变化？使用最先进的科学工具，如微生物测序和稳定同位素示踪，研究人员正在进行（1）实验室培养，以确定土壤微生物群落和矿物学如何影响植物分泌物的命运和融化的永久冻土中原生土壤有机质的脆弱性，（2）植物-土壤生长室中生态系统，在环境和高浓度CO2条件下追踪地下植物沉积物进入冻土。这些发现正在被用于开发和评估一种微生物激活的模型，该模型可以处理植物-微生物-矿物质反馈的复杂性。该土壤模型正在被整合到社区土地模型（CLM）中，以预测永久冻土融化对北极碳收支的影响。这项研究能够更好地长期预测永冻气候反馈。该项目正在通过博士助教、博士后研究和本科实验室教育，培养下一代精通从微生物基因到全球元素循环等尺度的跨学科北极学者。此外，该项目还为多达50名早期职业研究人员提供陆地建模理论和实践方面的培训，特别关注北极系统。该奖项反映了NSF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。