Testing a conceptual model of the terrestrial nitrogen cycle including rapid stabilization of nitrogen in soil

人类活动使每年输入生物圈的活性氮增加了一倍，对水和空气质量产生了重大影响。最近的研究表明，大多数无机氮迅速转化为有机形式，并有效地保留在土壤中几十年。该提案将测量森林、城市和农业生态系统稳定土壤有机质中氮的保持率和数量。这项研究是由一个概念模型的氮循环，明确包括一个稳定的有机池及其动态。该提案集中于三个问题：稳定土壤有机质中氮的保留率和数量是多少？微生物途径在稳定氮形成中的相对贡献是什么？有机氮形态的分子结构是什么？结果将被整合到高中课程的参与者在体验式学习和高中科学教学的专业知识，链接到学习的环境和生态，在该州最新的学习标准宾夕法尼亚州的标准。来自代表性不足群体的本科生将使用既定的计划招募。这项工作还将把来自生态学、化学和教育等不同领域的三名初级科学家联系起来。

Human activities have doubled annual reactive nitrogen inputs to the biosphere with major implications for water and air quality. Recent studies show that most inorganic nitrogen is rapidly converted to organic form and efficiently retained in soils for decades. This proposal will measure the rate and magnitude of nitrogen retention in stable soil organic matter of forest, urban, and agricultural ecosystems. The research is guided by a conceptual model for the nitrogen cycle that explicitly includes a stable organic pool and its dynamics. The proposal focuses on three questions: What are the rate and magnitude of nitrogen retention in stable soil organic matter? What is the relative contribution of the microbial pathway in stable nitrogen formation? What are the molecular structures of the organic nitrogen forms?Results will be integrated into high school curricula by a participant with expertise in experiential learning and high school science instruction, linking to Pennsylvania State Standards of Learning for the Environment and Ecology, the newest learning standards in the state. Undergraduate students from underrepresented groups will be recruited using established programs. The work will also link three junior level scientists from diverse fields of ecology, chemistry and education.