Collaborative Research: LTREB Renewal: Soil Warming and Forest Ecosystem Feedbacks to the Climate System

合作研究：LTREB更新：土壤变暖和森林生态系统对气候系统的反馈

• 批准号: 1949958
• 负责人: Serita Frey
• 金额: $ 29.9万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1949958&HistoricalAwards=false
• 关键词: Collaborative; Research; LTREB; Renewal; Soil

Soils are the largest repository of carbon (as organic matter) in the terrestrial biosphere. If this stored soil carbon is transferred to the atmosphere by a warming-induced acceleration of organic matter decomposition, it will result in a self-reinforcing (positive) feedback to the global environment. Despite the potential importance of this soil feedback, there is incomplete understanding of the mechanisms that affect the temperature response of organic matter decomposition. This project is quantifying the soil and ecosystem-level responses to nearly three decades of experimental soil warming and documenting the magnitude of soil carbon feedback to global environmental processes. Extensive training of undergraduates, graduate students and postdoctoral researchers will be another feature of this project. Data analysis from the study will also be incorporated into courses taught by the project leaders, and will be used to refine terrestrial ecosystem model projections.This project is investigating the mechanisms underlying feedback from forest ecosystems to the climate system resulting from more than two decades of in situ soil warming. Specifically, we are quantifying the biogeochemical and microbial responses to chronic soil warming, with an emphasis on soil organic matter (SOM) dynamics. This research is testing the hypothesis that long-term warming causes cycles of SOM decay punctuated by periods of structural and functional changes in the soil microbial community. Three ongoing warming experiments at the Harvard Forest Long-term Ecological Research (LTER) site have experienced 5 degrees C above ambient soil temperatures for 13, 16 and 28 years. Together, these sites represent a dynamic time-series based on a common perturbation in a single ecosystem type. Research activities to complete the decadal plan of this LTREB project are organized around four targeted research questions which are being addressed through (1) continuation of core data measurements; (2) temperature manipulations both in situ and under laboratory conditions to examine the underlying mechanistic basis for the observed pattern of temporal non-linearity in the soil respiration response to long-term warming; (3) measurements of SOM chemistry and microbial community dynamics to determine if long-term warming enables and accelerates decay of recalcitrant soil carbon due to a fundamental shift in the structure and/or function of the microbial community; (4) measurements of N mineralization and above-ground carbon storage to determine if long-term warming will continue to accelerate the N cycle and stimulate carbon storage in trees; and (5) data integration activities, including cross-site data syntheses and microbial trait-based and ecosystem modeling efforts.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.

土壤是陆地生物圈中碳（作为有机物）的最大仓库。如果将这种储存的土壤碳通过变暖引起的有机物分解加速转移到大气中，则将导致对全球环境的自我强化（积极）反馈。尽管这种土壤反馈具有潜在的重要性，但对影响有机物分解温度响应的机制有不完全理解。该项目正在量化土壤和生态系统水平的响应，以对近三十年的实验土壤变暖，并记录土壤碳反馈对全球环境过程的大小。对本科生和博士后研究人员的广泛培训将是该项目的另一个特征。 该研究的数据分析还将纳入项目领导者教授的课程中，并将用于完善陆地生态系统模型预测。该项目正在研究森林生态系统对气候系统的反馈基础的机制，该机制是由二十多年来的原位土壤变暖造成的。具体而言，我们正在量化对慢性土壤变暖的生物地球化学和微生物反应，重点是土壤有机物（SOM）动力学。这项研究正在检验以下假设：长期变暖会导致SOM衰减的循环，该衰减受土壤微生物群落的结构和功能变化时期的刺激。哈佛森林长期生态研究（LTER）部位正在进行的三个正在进行的变暖实验在13、16和28年的环境土壤温度高出5度。这些站点共同代表了基于单个生态系统类型中常见的扰动的动态时间序列。完成该LTREB项目的decadal计划的研究活动围绕四个有针对性的研究问题组织，这些问题正在通过（1）继续核心数据测量； （2）在原位和实验室条件下进行温度操作，以检查土壤呼吸反应对长期变暖的暂时性非线性模式的基本机理基础； （3）测量SOM化学和微生物群落动力学，以确定长期变暖是否可以使顽固的土壤碳的衰减导致微生物群落的结构和/或功能的根本变化，使顽固的土壤碳的衰减; （4）测量N矿化和地上碳储存的测量，以确定长期变暖是否会继续加速N周期并刺激树木中的碳储存； （5）数据集成活动，包括跨站点数据合成和基于微生物性状的和生态系统建模工作。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的评估评估来支持的。

项目成果

Soil aggregate-mediated microbial responses to long-term warming

• DOI: 10.1016/j.soilbio.2020.108055
• 发表时间: 2021
• 期刊: Soil Biology & Biochemistry
• 影响因子: 9.7
• 作者: Xiao‐Jun Allen Liu;G. Pold;L. Domeignoz-Horta;K. Geyer;H. Caris;Hannah Nicolson;K. Kemner;S. Frey;J. Melillo;Kristen M. DeAngelis

Chronic Warming and Nitrogen-Addition Alter Soil Organic Matter Molecular Composition Distinctly in Tandem Compared to Individual Stressors

• DOI: 10.1021/acsearthspacechem.2c00380
• 发表时间: 2023-02
• 期刊: ACS Earth and Space Chemistry
• 影响因子: 3.4
• 作者: I. Stoica;Maryam Tabatabaei Anaraki;Tom Muratore;M. Knorr;S. Frey;M. Simpson