Collaborative Research: MRA: A functional model of soil organic matter composition at continental scale

合作研究：MRA：大陆尺度土壤有机质组成的功能模型

• 批准号: 2307251
• 负责人: Steven Hall
• 金额: $ 32.39万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2307251&HistoricalAwards=false
• 关键词: Collaborative; Research; MRA; functional; model

Organic matter is a component of most soil that provides disproportionate and critical services to society. Soil organic matter influences fertility and plant growth, water quality and quantity, and global climate, due to its roles in storing carbon and nutrients and releasing them during decomposition. Predicting the distribution and functions of soil organic matter remains challenging despite more than a century of research on this topic. The ecosystem properties that influence soil organic matter vary tremendously over small and large spatial scales, and many previous studies have focused on a single soil type or geographic region. Scientists continue to debate the nature of soil organic matter and why it persists, given that microorganisms can inevitably decompose it over timescales of days to millennia. This project aims to reconcile previous debates regarding what soil organic matter consists of, and the physical, chemical, and biological factors that control its decomposition and capacity to supply nitrogen to plants. The study will combine a wealth of existing data with new samples and measurements from the National Ecological Observatory Network (NEON), a monitoring network including diverse sites across the U.S. Researchers will test a new quantitative framework to predict soil carbon and nitrogen cycling by incorporating multiple trade-offs in environmental characteristics at local to continental scales. The project will train graduate and undergraduate students, including those from underrepresented groups in science, and will develop soil-related curricula for a general educational audience. Many influential scientific concepts related to soil organic matter were developed within single ecosystem types and struggle to predict its distribution and dynamics at continental scale. The leaf economics spectrum showed that numerous aspects of plant diversity collapse along a fundamental axis of trait variation corresponding to fast vs. slow return on investment. However, the tremendous heterogeneity of soil and the lack of comprehensive and standardized data has stymied efforts to develop a similarly simple framework for predicting soil biogeochemical processes. This project will test whether variation in soil organic matter properties and cycling can be explained by three fundamental axes of ecosystem variation corresponding to fast and slow biogeochemical rates, each linked to interactions among climate, minerals, plants, microbes, and organic molecules, as supported by theory and preliminary data. Consideration of the composition of individual soil samples along each axis, and their joint influence on process rates, may help reconcile the importance of distinct mechanisms of organic matter persistence demonstrated in previous work, and thereby improve prediction of critical ecosystem functions that soil organic matter provides. To test this model, the researchers will collect new measurements of organic matter molecular composition, geochemistry and mineralogy, short- and long-term biogeochemical process rates, and microbial functional genes that leverage existing and ongoing data and sample collection from NEON sites. The project will include recruitment, education, and training of the future scientific, engineering, technical, and policy workforce and leadership needed to pursue basic research on regional to continental scale biology, as well as opportunities to engage a diverse community of learners and educators in regional to continental scale research and the use of NEON.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.

有机物是大多数土壤的组成部分，为社会提供了不成比例和关键的服务。土壤有机物会影响生育能力和植物生长，水质和数量以及全球气候，因为它在储存碳和养分中的作用并在分解过程中释放它们。尽管对该主题进行了一个多世纪的研究，但预测土壤有机物的分布和功能仍然具有挑战性。在小空间尺度上，影响土壤有机物的生态系统特性各不相同，许多先前的研究集中在单一的土壤类型或地理区域上。鉴于微生物不可避免地会在几天的时间表中，科学家继续辩论土壤有机物的性质及其为什么持续存在。该项目旨在调和先前关于土壤有机物组成的辩论，以及控制其分解和向植物提供氮的分解和能力的物理，化学和生物学因素。该研究将将大量现有数据与新样本和国家生态观测网络（NEON）的测量结合在一起，国家生态观测网络（NEON）是一个监测网络，包括美国研究人员的各种地点，将测试一个新的定量框架，以预测土壤碳和氮气环境，通过在当地的环境特征中纳入多个型号。该项目将培训毕业生和本科生，包括科学领域代表性不足的小组的研究生，并将为一般教育受众开发与土壤有关的课程。许多与土壤有机物有关的有影响力的科学概念都是在单一生态系统类型中开发的，并难以预测其在大陆规模上的分布和动态。叶子经济学频谱表明，植物多样性的许多方面沿着特质变异的基本轴崩溃，该轴对应于快速投资回报率。然而，土壤的巨大异质性以及缺乏全面和标准化的数据阻碍了开发一个类似简单的框架来预测土壤生物地球化学过程的同样简单框架。该项目将测试土壤有机物特性和循环的变化是否可以通过生态系统变化的三个基本轴对应于对应于快速和缓慢的生物地球化学速率，每种速率与气候，矿物质，植物，微生物和有机分子之间的相互作用有关，如理论和初步数据所支持。考虑沿每个轴的单个土壤样品的组成及其对过程速率的共同影响，可能有助于调和以前工作中证明的有机物持久性不同机制的重要性，从而改善了土壤有机物提供的关键生态系统功能的预测。为了测试该模型，研究人员将收集有机物分子组成，地球化学和矿物学，短期和长期生物地球化学过程速率以及微生物功能基因的新测量，这些基因利用了来自霓虹灯地点的现有数据以及持续的数据和样品收集的微生物功能。该项目将包括对未来科学，工程，技术，政策劳动力和领导力所需的招聘，教育以及培训，以便对大陆规模生物学区域的基础研究进行基础研究，以及参与区域性学习者和教育工作者的多元化社区与大陆规模研究的多元化社区的机会，以及NEON的使用以及NEON的使用。这些奖项反映了NSF的合法传统和良好的支持。 标准。