Dissertation Research: Effects of Increasing Nitrogen Inputs on Microbial Immobilization, Soil Nitrogen Retention, and Denitrification in an Aggrading Forest Ecosystem

由于农工活动的无意排放，美国几个地区的氮沉降有所增加。 该项目旨在调查温带森林中氮输入的三个重要命运：微生物固定化，掺入缓慢分解的土壤有机质和反硝化气体排放。 这些汇保留氮输入的能力可能决定森林生态系统的可持续性，并可能影响全球变暖和水生生态系统的健康。 例如，随着氮输入的增加，反硝化作用的增加可能导致一氧化二氮（一种强效温室气体）排放量的增加。 该项目将调查土壤通过生物（微生物）和非生物（物理化学）机制保持氮的能力，以及反硝化作用对环境条件变化和微生物生物多样性变化的反应。 这项研究的结果将是至关重要的，以预测森林生态系统的反应，增加氮沉降。

Nitrogen deposition has increased in several regions in the United States due to inadvertent emissions from agro-industrial activities. This project is designed to investigate three important fates for nitrogen inputs in temperate forests: microbial immobilization, incorporation into slowly decomposing soil organic matter, and denitrification gas emissions. The ability of these sinks to retain nitrogen inputs may determine the sustainability of forest ecosystems and may affect global warming and aquatic ecosystem health. For example, as nitrogen inputs increase, increased denitrification may result in increased emissions of nitrous oxide, a potent greenhouse gas. This project will investigate the ability of soils to retain nitrogen through biotic (microbial) and abiotic (physiochemical) mechanisms, and the response of denitrification to changes in environmental conditions and changes in microbial biodiversity. The results of this study will be critical to predicting the response of forest ecosystems to increasing nitrogen deposition.