NSFDEB-NERC: Mycorrhizal drivers of soil organic matter formation and decomposition

NSFDEB-NERC：土壤有机质形成和分解的菌根驱动因素

• 批准号: 1743237
• 负责人: Francesca Cotrufo
• 金额: $ 49.94万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-15 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1743237&HistoricalAwards=false
• 关键词: NSFDEB; NERC; Mycorrhizal; drivers; soil

Changes in land cover, such as the transition from grassland to forest, or vice-versa, have become a common occurrence. Changes in soil microorganisms, such as fungi associated with plant root structures, can accompany these vegetation changes. Because the formation and decomposition of soil organic matter is determined by plant-microbe-soil interactions, the land-cover change may result in a change in the accrual, storage and physical protection of soil organic matter. This US-UK collaborative project, using state-of-the-art methods, will investigate how grasslands and forests, with their different types of symbiotic root fungi, transform plant residue inputs and soil organic matter. Experiments will determine whether the transition from grassland to forests enhances or degrades soils. Additionally, the research will create new computational tools to model soils to better predict carbon and nitrogen dynamics after land cover change. This research will help managers identify sustainable land management decisions through more accurate forecasting of future terrestrial carbon cycling. In addition to international collaboration, this project will provide mentoring for post-doctoral scientists and undergraduate students. This research will (1) determine the mechanisms by which temperate grasses and coniferous trees in interaction with their associated mycorrhizae affect soil organic matter formation and decomposition; (2) integrate this mechanistic understanding in a new process based model; and (3) use existing chronosequences of land use change from grassland to forest to independently verify model projections of long-term changes in ecosystem C stores. The project consists in an integrated set of greenhouse, field and modelling studies, with different components carried out in the US and UK. Continuous 13C isotope-labeling of plant and mycorrhizal biomass will be used to accurately trace the fate of root exudates and mycorrhizal products as they form particulate or dissolved organic matter, and then stabilize via physical occlusion or mineral bonding. In the field, the effects of different mycorrhizal types on the decomposition of 13C-labeled grass and tree residues, CO2 production, and soil organic matter formation will be determined. Bayesian inference will be used to parameterize the new model using the experimental data, and model projections will be evaluated using data on carbon stock changes collected from a grassland-forest transition chronosequences. The degree of soil organic matter stabilization by physical occlusion or mineral-association will be used to evaluate the process-model based findings and inform on the reliability of the new model as a policy tool for C cycling projections and ecosystem management.

土地覆被的变化，例如从草原到森林的过渡，或相反的过渡，已成为司空见惯的现象。土壤微生物的变化，如与植物根系结构相关的真菌，可以伴随着这些植被的变化。由于土壤有机质的形成和分解是由植物-微生物-土壤相互作用决定的，土地覆被变化可能导致土壤有机质的积累、储存和物理保护的变化。这项美英合作项目将采用最先进的方法，研究草原和森林如何利用不同类型的共生根真菌转化植物残留物和土壤有机质。 实验将确定从草地到森林的过渡是增强还是退化土壤。此外，该研究将创建新的计算工具来模拟土壤，以更好地预测土地覆盖变化后的碳和氮动态。这项研究将有助于管理人员通过更准确地预测未来陆地碳循环来确定可持续的土地管理决策。除了国际合作外，该项目还将为博士后科学家和本科生提供指导。本研究将（1）确定温带草和针叶树与其相关的真菌相互作用影响土壤有机质形成和分解的机制;（2）将这种机制的理解整合到一个新的基于过程的模型中;（3）使用现有的土地利用从草地到森林的变化时序，独立验证生态系统碳储量长期变化的模型预测。该项目包括一套综合的温室，实地和模拟研究，不同的组成部分在美国和英国进行。植物和菌根生物量的连续13 C同位素标记将用于准确追踪根分泌物和菌根产物的命运，因为它们形成颗粒或溶解的有机物，然后通过物理封闭或矿物结合来稳定。 在现场，不同类型的菌根对13 C标记的草和树的残留物，CO2的生产，和土壤有机质的形成分解的影响将被确定。贝叶斯推断将用于使用实验数据的新模型的参数化，模型预测将使用从草地-森林过渡时序收集的碳储存变化数据进行评估。物理闭塞或矿物协会的土壤有机质稳定的程度将被用来评估过程模型为基础的调查结果，并告知新模型的可靠性，作为碳循环预测和生态系统管理的政策工具。

项目成果

Unifying soil organic matter formation and persistence frameworks: the MEMS model

• DOI: 10.5194/bg-16-1225-2019
• 发表时间: 2018-10
• 期刊: Biogeosciences
• 影响因子: 4.9
• 作者: Andy D. Robertson;K. Paustian;S. Ogle;M. Wallenstein;E. Lugato;M. F. Cotrufo

Simulating measurable ecosystem carbon and nitrogen dynamics with the mechanistically defined MEMS 2.0 model

• DOI: 10.5194/bg-18-3147-2021
• 发表时间: 2021-05
• 期刊: Biogeosciences
• 影响因子: 4.9
• 作者: Yao Zhang;J. Lavallee;A. Robertson;Rebecca Even;S. Ogle;K. Paustian;M. Cotrufo

Soil carbon storage informed by particulate and mineral-associated organic matter

• DOI: 10.1038/s41561-019-0484-6
• 发表时间: 2019-12-01
• 期刊: NATURE GEOSCIENCE
• 影响因子: 18.3
• 作者: Cotrufo, M. Francesca;Ranalli, Maria Giovanna;Lugato, Emanuele
• 通讯作者: Lugato, Emanuele