Dissertation Research: Disentangling temperature controls on turnover of old, nitrogen-rich soil organic matter

论文研究：解开温度对旧富氮土壤有机质周转的控制

• 批准号: 1310821
• 负责人: Richard Conant
• 金额: $ 1.93万
• 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: 2013
• 资助国家: 美国
• 起止时间: 2013-05-15 至 2016-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1310821&HistoricalAwards=false
• 关键词: Dissertation; Research; Disentangling; temperature; controls

Soil organic matter is the largest land reservoir of carbon and nitrogen, the two major building blocks of all life on earth. Warmer temperatures may accelerate the breakdown of soil organic matter by microorganisms, causing major shifts in the dynamics of carbon and nitrogen. Among other impacts, the transformation of soil organic carbon into carbon dioxide in the atmosphere could intensify climate change. But warming will accelerate soil organic matter breakdown only if microbes have access to it. Stabilization of organic matter in soils by minerals is the dominant control on the availability of soil organic matter to microbes and so is the key to understanding how soil carbon and nitrogen will respond to warming. The approach proposed here uses a simple, realistic soil incubation experiment involving plant material labeled with isotopes to reveal the effects of warming. This experiment improves upon previous work by enabling tight control over carbon inputs and other driving variables (temperature, moisture, etc.), while using real plant material and soils. The results will improve our ability to predict future climate change and advance our understanding of the global carbon and nitrogen cycles. Throughout this study, the results will be disseminated through the mentoring of undergraduate students and presentations made at scientific meetings. The investigators will work with the Academic Advancement Center at Colorado State University, to recruit a low-income, first-generation and disabled student into a new program for undergraduate research. This student will take part in a series of workshops designed to improve scientific literacy and critical thinking and will be involved in every aspect of this project. At the culmination of this work, results will be presented at the 6th International Workshop on Soil and Sedimentary Organic Matter Stabilization and Destabilization and at the Colorado Front Range Student Ecology Symposium. By attending meetings designed for different audiences, the results will be made broadly available and integrated into research in multiple fields.

土壤有机物是碳和氮的最大土地储层，这是地球上所有生命的两个主要基础。较高的温度可能会加速微生物的土壤有机物的分解，从而导致碳和氮动力学的重大变化。除其他影响外，在大气中，土壤有机碳转化为二氧化碳可能会加剧气候变化。但是，只有在微生物可以使用它的情况下，变暖才能加速土壤有机物的分解。通过矿物质对土壤中有机物的稳定是对土壤有机物对微生物的可用性的主要控制，因此了解土壤碳和氮将如何对变暖做出反应的关键。这里提出的方法使用了一个简单，逼真的土壤孵化实验，该实验涉及带有同位素标记的植物材料来揭示变暖的作用。该实验可以通过对碳输入和其他驾驶变量（温度，水分等）进行严格控制，同时使用真实的植物材料和土壤，从而改善了以前的工作。结果将提高我们预测未来气候变化并提高我们对全球碳和氮气周期的理解的能力。在整个研究中，通过指导本科生和科学会议上的演讲来传播结果。调查人员将与科罗拉多州立大学的学术进步中心合作，招募低收入，第一代和残疾学生参加新的本科研究计划。该学生将参加一系列旨在提高科学素养和批判性思维的研讨会，并将参与该项目的各个方面。在这项工作的高潮中，结果将在第六届国际土壤和沉积有机物稳定和不稳定的国际研讨会上介绍，以及在科罗拉多州前范围的学生生态研讨会。通过参加为不同受众设计的会议，将在多个领域中广泛提供结果并将其集成到研究中。