Does Sediment Storage Set the Pace of the Terrestrial Organic Carbon Cycle?

沉积物储存是否决定了陆地有机碳循环的步伐？

• 批准号: 2017106
• 负责人: Mark Torres
• 金额: $ 41.38万
• 依托单位: William Marsh Rice University
• 依托单位国家: 美国
• 项目类别: Continuing 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=2017106&HistoricalAwards=false
• 关键词: Does; Sediment; Storage; Set; Pace

The amount of carbon present in soils is larger than the amount of carbon dioxide in the atmosphere. This means changes in soil carbon storage can affect the climate. Soil carbon also affects the fertility of agricultural soil, and can influence local water quality. Given such significant implications on human and environmental wellbeing, this proposal seeks to enhance understanding of soil carbon storage. Research will focus on the role of rivers, which control the amount of time soil remains on landscapes before being eroded and which, through flooding, influence where new soil is formed. Rivers can also influence the chemical conditions in soil that affect soil carbon. Work will take place in a watershed containing only volcanic rocks to avoid the “fossil” carbon present in other rock types. Key outcomes include a new predictive model for soil carbon, the training of a graduate student and two elementary school teachers in biogeochemistry, and the development of bilingual educational materials for elementary school students. The biogeochemical mechanisms thought to stabilize terrestrial organic carbon (OC) all evolve over similar (millennial) timescales to the duration over which soil and sediment are stored on landscapes. Consequently, a holistic view of the terrestrial OC cycle that leverages knowledge of the storage processes has the potential improve predictions and reveal novel dynamics, but requires new data and quantitative models for validation and application. This work aims to address these specific knowledge gaps by testing 3 hypotheses related to the coupling between soil, sediment, and OC storage: (1) the age distribution of OC inherits its shape from the fluvial processes that regulate storage times, (2) storage processes influence the loci and biogeochemical mechanisms(s) of OC preservation via fluvial controls on grain size sorting and hydrology, and (3) post-glacial landscape evolution increases the size of the terrestrial OC reservoir via an increase in landscape soil and sediment storage. These hypotheses will be evaluated using estimates of sediment storage from remote-sensing and surveying, radionuclide-based determinations of sediment and OC storage times, as well as elemental, molecular, and isotopic constraints on the biogeochemical mechanisms of OC preservation.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.

土壤中的碳含量大于大气中的二氧化碳含量，这意味着土壤碳储存的变化也会影响农业土壤的肥力，并影响当地的水质。该提案旨在加强对土壤碳储存的了解，研究重点是河流的作用，河流控制土壤在被侵蚀之前保留在景观上的时间，并通过洪水影响新的土壤。土壤的形成也会影响化学物质。影响土壤碳的土壤条件将在仅含有火山岩的流域进行，以避免其他岩石类型中存在的“化石”碳。主要成果包括新的土壤碳预测模型、研究生培训和两名小学生物地球化学教师，以及为小学生开发双语教材。被认为稳定陆地有机碳（OC）的生物地球化学机制都在与土壤持续时间相似的（千年）时间尺度上演变。通过对沉积物和沉积物储存在景观中的研究，利用储存过程知识的陆地有机碳循环的整体视图有可能改善预测并揭示新的动态，但需要新的数据和定量模型进行验证和应用。通过测试与土壤、沉积物和 OC 储存之间的耦合相关的 3 个假设来解决这些具体的知识差距：(1) OC 的年龄分布从调节储存时间的河流过程继承其形状，(2) 储存过程影响位点和通过河流对颗粒大小分选和水文的控制来保存有机碳的生物地球化学机制，以及（3）冰川后景观演化通过景观土壤和沉积物储存的增加增加了陆地有机碳库的规模。将对这些假设进行评估。利用遥感和测量对沉积物储存量的估计，基于放射性核素的沉积物和有机碳储存时间的测定，以及对沉积物生物地球化学机制的元素、分子和同位素限制OC 保存。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力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

Competition or collaboration: Clay formation sets the relationship between silicate weathering and organic carbon burial in soil

竞争还是合作：粘土的形成决定了硅酸盐风化与土壤中有机碳埋藏之间的关系

• DOI: 10.1016/j.epsl.2024.118584
• 发表时间: 2024-02
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: Ramos, Evan J.;Larsen, William J.;Hou, Yi;Muñoz, Sebastian;Kemeny, Preston Cosslett;Scheingross, Joel S.;Repasch, Marisa N.;Hovius, Niels;Sachse, Dirk;Ibarra, Daniel E.;et al
• 通讯作者: et al

Autogenic Signals in the Sedimentary Record of Organic Carbon Preservation

有机碳保存沉积记录中的自生信号

• DOI: 10.1029/2021gl097654
• 发表时间: 2022-05
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Hou, Yi;Torres, Mark A.
• 通讯作者: Torres, Mark A.

The Hydrochemical Signature of Incongruent Weathering in Iceland

冰岛不一致风化的水化学特征

• DOI: 10.1029/2021jf006450
• 发表时间: 2021-09-29
• 期刊: Journal of Geophysical Research: Earth Surface
• 作者: T. Cole;M. Torres;P. Kemeny
• 通讯作者: P. Kemeny