Collaborative Research: BoCP-Design: US-South Africa: Turning CO2 to stone: the ecosystem service of the oxalate-carbonate pathway and its sensitivity to land use change

合作研究：BoCP-设计：美国-南非：将二氧化碳转化为石头：草酸盐-碳酸盐途径的生态系统服务及其对土地利用变化的敏感性

• 批准号: 2224994
• 负责人: Daniel Breecker
• 金额: $ 15.02万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2224994&HistoricalAwards=false
• 关键词: Collaborative; Research; BoCP; Design; US

Mitigation of global warming requires a complete understanding of carbon exchange between the atmosphere and the land. Near-surface terrestrial carbon storage typically focuses on above-ground plants and organic carbon in soils, even though these forms of carbon are relatively unstable. Calcium carbonate (CaCO3) is a mineral that is regularly overlooked as a long-term and stable carbon store in soils. In dry environments where plants are rich in calcium oxalate, certain bacteria and fungi can decompose the calcium oxalate in dead plant material, which can lead to the formation of CaCO3. This oxalate-carbonate pathway (OCP) provides a natural and potentially rapid way to sequester atmospheric CO2-carbon as solid CaCO3. This project will investigate how loss of biodiversity through land-use change and agricultural practices may reduce the amount of carbon that is transformed into CaCO3. The project will develop an international team of ecologists, soil scientists, and geochemists through a series of fieldtrips, graduate student exchanges, and work packages that uses a multidisciplinary approach to understanding the importance and resilience of OCP ecosystems within the Greater Cape Floristic Region of South Africa. The project aims to develop a toolset that can ultimately be applied to investigate other candidate ecosystems worldwide. Many such ecosystems are being converted to agriculture but are only marginally productive. Knowledge generated from this project will be shared with land users to inform decisions on land conversion, the potential valuation of carbon, and how this could be applied to improve monetary yields.This project will investigate how the loss of functional biodiversity limits sequestration of carbon by the OCP in two important ways: 1) removal of native, calcium-oxalate rich vegetation (through farming and/or overgrazing) and physical disruption of giant termite mounds (through deep tillage) limits the supply of calcium-oxalate to the soil, and 2) loss of soil microbial diversity limits the breakdown of available calcium-oxalate. The interdisciplinary project will use eDNA-based functional biodiversity methods to identify the soil microbial assemblage that is the cornerstone of the proposed carbon sequestration pathway and how it changes upon disturbance; monitor the soil pore space apparent respiratory quotient (ratio of CO2 produced to O2 consumed) to spatially and temporally resolve the OCP non-destructively in soils; use stable Ca isotopes to trace the movement of calcium through plants and soils to help evaluate the time-integrated importance of the OCP; and develop a method for near and mid-infrared spectroscopy to measure Ca oxalate and calcite concentration that does not rely on prior dissolutions or precipitation.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.

缓解全球变暖需要完全了解大气与土地之间的碳交换。近地表地面碳储存通常集中在地上植物和土壤中的有机碳上，即使这些形式的碳相对不稳定。碳酸钙（CACO3）是一种矿物质，经常被视为土壤中的长期且稳定的碳存储。在植物富含草酸钙的干燥环境中，某些细菌和真菌可以在死植物材料中分解草酸钙，从而导致CACO3的形成。该草酸盐碳酸盐途径（OCP）提供了一种自然而潜在的快速方法，将大气二氧化碳作为固体CACO3提供了隔离。该项目将通过土地利用变化和农业实践来调查生物多样性损失如何减少转化为CACO3的碳量。该项目将通过一系列实地考察，研究生交流以及使用多学科方法来理解南非大开普敦花店内OCP生态系统的重要性和韧性的一系列实地考察，研究生交流和工作套餐的国际团队。该项目旨在开发一种最终可以应用于全球其他候选生态系统的工具集。许多这样的生态系统正在转化为农业，但仅略有生产力。该项目产生的知识将与土地用户共享，以告知有关土地转化的决定，潜在的碳估值以及如何应用于提高货币产量的应用。该项目将调查功能性生物多样性的丧失如何以两种重要方式限制OCP隔离碳的隔离方式：1：1）通过，通过菌根且富含植被（或过度刺激）的植物（或过度刺激）（）杂物（）深耕作）将钙 - 氧盐的供应限制在土壤中，2）土壤微生物多样性的丧失限制了可用钙 - 氧甲酸盐的分解。跨学科项目将使用基于EDNA的功能生物多样性方法来识别所提出的碳固隔途径的基石及其在干扰时如何变化的土壤微生物组合。监测土壤孔隙空间明显的呼吸商（二氧化碳与O2消耗的二氧化碳比率），以空间和时间在土壤中无损地解决OCP；使用稳定的Ca同位素追踪钙通过植物和土壤的运动，以帮助评估OCP的时间融合的重要性；并开发一种不依赖于先前溶解或降水的近红外光谱法测量的近红外光谱法和方解石浓度。该奖项反映了NSF的法定任务，并认为值得通过基金会的智力优点和更广泛的影响审查标准通过评估来获得支持。

项目成果

Oxalate and oxalotrophy: an environmental perspective

草酸盐和草酸营养不良：环境视角

• DOI: 10.1093/sumbio/qvad004
• 发表时间: 2024
• 期刊: Sustainable Microbiology
• 作者: Cowan, Don A.;Babenko, Darya;Bird, Ryan;Botha, Alf;Breecker, Daniel O.;Clarke, Cathy E.;Francis, Michele L.;Gallagher, Tim;Lebre, Pedro H.;Nel, Teneille
• 通讯作者: Nel, Teneille