OPUS: MCS - Developing a mechanistic understanding of decomposition of organic matter in frozen soil

在冬季，土壤微生物可以保持活跃，即使在冻结的土壤中也是如此。已有研究表明，土壤微生物可以在越冬期间继续生存和发挥作用。这些微生物的活动对生态系统的碳和养分循环可能很重要。但是，目前还不清楚微生物在冬天在冻土中做了什么。这个项目将通过开发一个模型来了解冻土带土壤中的微生物活动，从而促进对冬季过程的理解。该项目还将为职业生涯中期的科学家提供在生态系统建模方面获得新研究能力的机会。该项目建立在北极碳循环实地研究的丰富历史基础上。该项目将通过与本科生研究计划的整合，产生重大的教育影响，从而加强科学界。该项目将探索驱动土壤呼吸季节性模式的机制。中心目标是了解冬季呼吸对温度和植被变化的反应。该项目将支持开发一个结合了冷季过程的强大的机械模型。关键是将植物、土壤和微生物中的碳和养分循环联系起来。该模型将以现有的资源获取和分配模型为基础。这项新工作将在基质可用性和冻融动力学之间增加新的联系。该模型将为冻土带生态系统开发。但这一结果将与任何季节性冻结的生态系统相关。该项目将加深对生态系统过程的理解，这些过程可能是季节性分离的，但具有很强的植物-微生物联系。该项目将解决生态系统生态学中有关冬季资源获取、分配和养分循环的基本问题。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。

During the winter season, soil microbes can remain active, even in frozen soils. It has been shown that soil microbes can continue to live and function over the winter. The activities of these microbes can be important for ecosystem carbon and nutrient cycling. But, it is not known exactly what microbes are doing in frozen soils over the winter. This project will advance understanding of winter processes by developing a model to understand microbial activity in frozen tundra soils. This project will also provide a mid-career scientist with an opportunity to gain new research capabilities in ecosystem modeling. The project builds on a rich history of field studies of carbon cycling in the Arctic. The project will have substantial educational impact, through integration with an undergraduate research program, thereby strengthening the scientific community.This project will explore the mechanisms that drive seasonal patterns of soil respiration. The central goal is to understand the response of winter respiration to changes in temperature and vegetation. The project will support development of a robust mechanistic model that incorporates cold season processes. The key is to link carbon and nutrient cycling in plants, soils, and microbes. The model will be based on an existing resource acquisition and allocation model. The new work will add new connections between substrate availability and freeze-thaw dynamics. The model will be developed for tundra ecosystems. But the results will be relevant to any seasonally-frozen ecosystem. This project will deepen understanding of ecosystem processes that may be seasonally disconnected but have strong plant-microbial linkages. This project will address fundamental questions in ecosystem ecology about resource acquisition, allocation, and nutrient cycling during the winter.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.