Composition and Bioavailability of Dissolved Organic Nitrogen in Atmospheric Deposition (EGB)

9807621 Seitzinger陆地和水生生态系统的显著变化是由于大气沉积中人为氮（N）增加的结果。 据预测，在未来20年内，氮沉降量将增加两倍以上。 迄今为止，大多数关于大气沉积氮的数量、来源和影响的研究都只考虑无机氮。 然而，雨水中相当大一部分的N是以有机N的形式存在的，并且几乎不知道大部分有机N的化学组成、来源或生态系统效应。 拟议的研究将：（1）研究了大气沉降中溶解有机氮（DOM）的化学组成特征：（2）研究了美国东北部一个相对扰动点大气沉降中DOM的化学组成特征;（三）确定春季雨水中有多少总DOM可供沿海浮游生物群落生物利用，并提供潜在变化的见解（4）开始确定具有生物可利用性的DOM化合物类别的化学组成，从而有助于接收生态系统的生态变化。该方法将提供总氮（有机氮和无机氮）和各种形式的有机氮在降水中的质量平衡。 化学特性研究将与生态研究相结合。 这项研究将产生所需的信息，以帮助了解污染物和天然氮大气化合物在美国东北部的大陆途径。此外，通过将生物利用度研究与降水氮负荷和组成相联系，大气处理的氮化合物将与敏感的生态系统相关。该项目将为罗格斯大学道格拉斯学院的本科生提供研究机会。 本科生在本研究计划的整合将为学生和研究人员提供一个框架，共同探索人类活动/土地利用，大气地球化学过程和水生生态系统中的地球化学过程之间的重要联系。9807621 Seitzinger在陆地和水生生态系统的显着变化正在发生的结果增加人为氮（N）在大气沉积。 据预测，在未来20年内，氮沉降量将增加两倍以上。 迄今为止，大多数关于大气沉积氮的数量、来源和影响的研究都只考虑无机氮。 然而，雨水中相当大一部分的N是以有机N的形式存在的，并且几乎不知道大部分有机N的化学组成、来源或生态系统效应。 拟议的研究将：（1）研究了大气沉降中溶解有机氮（DOM）的化学组成特征：（2）研究了美国东北部一个相对扰动点大气沉降中DOM的化学组成特征;（三）确定春季雨水中有多少总DOM可供沿海浮游生物群落生物利用，并提供潜在变化的见解（4）开始确定具有生物可利用性的DOM化合物类别的化学组成，从而有助于接收生态系统的生态变化。该方法将提供总氮（有机氮和无机氮）和各种形式的有机氮在降水中的质量平衡。 化学特性研究将与生态研究相结合。 这项研究将产生所需的信息，以帮助了解污染物和天然氮大气化合物在美国东北部的大陆途径。此外，通过将生物利用度研究与降水氮负荷和组成相联系，大气处理的氮化合物将与敏感的生态系统相关。该项目将为罗格斯大学道格拉斯学院的本科生提供研究机会。 本科生在本研究计划的整合将为学生和研究人员提供一个框架，共同探索人类活动/土地利用，大气地球化学过程和水生生态系统中的地球化学过程之间的重要联系。

9807621SeitzingerMarked changes in both terrestrial and aquatic ecosystems are occurring as a result of increased anthropogenic nitrogen (N) in atmospheric deposition. N deposition is predicted to increase over twofold in the next 20 years. To date, most studies of the magnitude, sources and effects of atmospherically deposited N have only considered inorganic-N. However, a considerable portion of N in rainwater is in the form of organic-N, and almost nothing is known of the chemical composition, sources or ecosystem effects of the bulk of that organic-N. The proposed studies will: (1) develop to characterize the chemical composition of dissolved organic nitrogen (DOM) in atmospheric deposition; (2) characterize the chemical compositon of DOM in atmospheric deposition at a relatively perturbed site in the Northeastern U.S. over an annual cycle; (3) determine how much of the total DOM in the rainwater in spring is biologically available to coastal plankton communities and provide insight into potential changes in plankton production and community composition; and (4) begin to characterize the chemical composition of the DOM compound classes that are bio-available and thus contributing to ecological changes in receiving ecosystems. The approach will provide a mass balance of total N (organic-N and inorganic-N) and of the various forms of organic N in precipitation. The chemical characterization studies will be integrated with ecological studies. This study will generate information needed to help understand the continental pathways of pollutant and natural N atmospheric compounds in the Northeastern U.S.. Moreover, by linking the bioavailability studies with precipitation N loading and composition, atmospherically processed N compounds will be related to sensitive ecosystems. The project will provide research opportunities for undergraduates to Rutgers University Douglass College. Integration of undergraduate students in this research program will provide the framework for students and researchers to explore together important linkages among human activities/land use, atmospheric geochemical processes, and biogeochemical processes in aquatic ecosystems.9807621SeitzingerMarked changes in both terrestrial and aquatic ecosystems are occurring as a result of increased anthropogenic nitrogen (N) in atmospheric deposition. N deposition is predicted to increase over twofold in the next 20 years. To date, most studies of the magnitude, sources and effects of atmospherically deposited N have only considered inorganic-N. However, a considerable portion of N in rainwater is in the form of organic-N, and almost nothing is known of the chemical composition, sources or ecosystem effects of the bulk of that organic-N. The proposed studies will: (1) develop to characterize the chemical composition of dissolved organic nitrogen (DOM) in atmospheric deposition; (2) characterize the chemical compositon of DOM in atmospheric deposition at a relatively perturbed site in the Northeastern U.S. over an annual cycle; (3) determine how much of the total DOM in the rainwater in spring is biologically available to coastal plankton communities and provide insight into potential changes in plankton production and community composition; and (4) begin to characterize the chemical composition of the DOM compound classes that are bio-available and thus contributing to ecological changes in receiving ecosystems. The approach will provide a mass balance of total N (organic-N and inorganic-N) and of the various forms of organic N in precipitation. The chemical characterization studies will be integrated with ecological studies. This study will generate information needed to help understand the continental pathways of pollutant and natural N atmospheric compounds in the Northeastern U.S.. Moreover, by linking the bioavailability studies with precipitation N loading and composition, atmospherically processed N compounds will be related to sensitive ecosystems. The project will provide research opportunities for undergraduates to Rutgers University Douglass College. Integration of undergraduate students in this research program will provide the framework for students and researchers to explore together important linkages among human activities/land use, atmospheric geochemical processes, and biogeochemical processes in aquatic ecosystems.