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

人类活动使生物圈的年度活性氮输入翻了一番，对水和空气质量产生了重大影响。最近的研究表明，大多数无机氮被迅速转化为有机形态，并有效地保留在土壤中数十年。这项建议将测量森林、城市和农业生态系统稳定土壤有机质中氮素的滞留速度和幅度。这项研究是在氮循环概念模型的指导下进行的，该模型明确包括一个稳定的有机库及其动态。该提案集中于三个问题：稳定土壤有机质中氮素的滞留速度和幅度是多少？微生物途径在稳定氮素形成中的相对贡献是什么？有机氮的分子结构是什么？结果将由一位在体验式学习和高中科学教学方面有专长的参与者整合到高中课程中，并与宾夕法尼亚州环境与生态学习标准(宾夕法尼亚州环境与生态学习标准)相联系，这是该州最新的学习标准。来自代表人数不足的群体的本科生将使用现有的计划进行招生。这项工作还将把来自生态、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.