CAREER: Manganese biogeochemistry and impacts on carbon storage in plant-soil systems

职业：锰生物地球化学及其对植物-土壤系统碳储存的影响

• 批准号: 1749849
• 负责人: Elizabeth Herndon
• 金额: $ 48.72万
• 依托单位: Kent State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-06-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1749849&HistoricalAwards=false
• 关键词: CAREER; Manganese; biogeochemistry; impacts; carbon

Soils contain large quantities of organic matter that both improve soil health and regulate atmospheric carbon dioxide levels by storing carbon (C). Metals such as manganese (Mn) can influence how much organic C is stored in soils by impacting plant growth and by helping to either stabilize or degrade organic compounds in the soil. This research will explore how Mn cycling between soils and plants influences storage of organic C in terrestrial ecosystems. This project will also create a network of educational opportunities for graduate and undergraduate students as well as K-12 educators and students. The educational objectives are to improve science literacy, integrate research with education, and broaden participation in geosciences by distributing earth science activities to regional K-12 educators through the Cleveland Museum of Natural History (CMNH). This project will also provide training for multiple graduate and undergraduate students who will be integral participants in both the research and educational components of the project.Manganese is a biologically important and redox-active trace metal that may exert a poorly recognized control on carbon cycling in terrestrial ecosystems; however, the mechanisms by which Mn increases or decreases long-term carbon storage remains unclear. Although substantial research has been devoted to understanding how iron and aluminum oxides stabilize organic carbon, there is a scarcity of similar information regarding Mn oxides. Added to this knowledge gap are uncertainties related to how soil geochemistry regulates plant uptake of Mn, and how elevated foliar Mn impacts carbon loss and transformation during litter decomposition. The overarching hypothesis of this research is that vegetation regulates the geochemistry of manganese in terrestrial systems with secondary effects on organic carbon storage in soils. The implication of this hypothesis is that Mn is an unrecognized but significant regulator of the global C cycle. This research will integrate studies across multiple scales to explore three major components of manganese biogeochemistry and associated impacts on carbon cycling in the critical zone: (1) geochemical controls on rates of Mn cycling by forest vegetation; (2) influence of elevated foliar Mn on the quantity and chemical composition of organic C released during litter decomposition; (3) influence of Mn oxides on the storage or transformation of organic matter. Results will be integrated into a quantitative framework describing Mn-C interactions in plant-soil systems and lay the groundwork for future exploration of manganese biogeochemistry and coupled metal-organic interactions.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.

土壤含有大量的有机物质，既能改善土壤健康，又能通过储存碳(C)来调节大气中的二氧化碳水平。像锰这样的金属可以通过影响植物生长和帮助稳定或降解土壤中的有机化合物来影响土壤中有机碳的储存量。这项研究将探索土壤和植物之间的锰循环如何影响陆地生态系统中有机碳的储存。该项目还将为研究生和本科生以及K-12教育工作者和学生创造一个教育机会网络。教育目标是提高科学素养，将研究与教育结合起来，通过克利夫兰自然历史博物馆(CMNH)向地区K-12教育工作者分发地球科学活动，扩大对地球科学的参与。该项目还将为多名研究生和本科生提供培训，他们将成为该项目研究和教育部分的不可或缺的参与者。锰是一种具有生物重要性和氧化还原活性的痕量金属，它可能对陆地生态系统中的碳循环起到很不为人所知的控制作用；然而，锰增加或减少长期碳储存的机制尚不清楚。虽然已有大量研究致力于了解铁和铝氧化物如何稳定有机碳，但关于锰氧化物的类似信息很少。除了这一知识缺口，还有与土壤地球化学如何调节植物对锰的吸收有关的不确定性，以及叶片锰含量升高如何影响凋落物分解过程中的碳损失和转化。这项研究的主要假设是，植被调节陆地系统中锰的地球化学，并对土壤有机碳储量产生次要影响。这一假设的含义是，锰是全球碳循环的一个未被认识但意义重大的调节因子。这项研究将结合多个尺度的研究，探索临界区锰生物地球化学的三个主要组成部分及其对碳循环的影响：(1)森林植被对锰循环速率的地球化学控制；(2)叶面锰升高对凋落物分解释放的有机碳的数量和化学组成的影响；(3)锰氧化物对有机质储存或转化的影响。结果将被整合到描述植物-土壤系统中锰-碳相互作用的量化框架中，并为未来探索锰生物地球化学和金属-有机耦合作用奠定基础。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。