ETBC: A new tool for assessing nitrogen saturation status in forests- Mass-independent D17O of nitrate

ETBC：一种评估森林氮饱和状态的新工具？ 硝酸盐的质量无关氧同位素Emily M.埃利奥特，首席研究员爱丁堡大学项目摘要随着美国森林的不断老化，森林中的硝酸盐淋失可能成为地表水质量损害的一个越来越重要的因素。 该项目建立了一个质量无关的氧同位素示踪剂的大气硝酸盐的经验工具，量化出口的大气硝酸盐从森林流域和评估缺乏长期水质数据的流域的氮饱和状态。 研究的目标包括以下几个方面：1）开发一种新的经验工具，用于准确地量化流域的大气硝酸盐输出和相关的氮饱和状态; 2）在氮饱和系统中，土壤水渗滤液中硝酸盐源的空间异质性的流域内评估;和3）在情景酸化暴雨流期间，硝酸盐源到流水的高分辨率时间动态特性。 这项研究预计将提供一个无与伦比的能力，以更高的空间分辨率比以前可能的慢性氮沉降的影响进行评估，改变我们对大气沉积，生态系统健康和水质之间的相互作用的理解。 此外，该项目将产生新的见解，森林管理策略如何影响大气氮输出，对敏感系统的水质管理具有重要意义，并提高我们对大气氮输出时空变化的过程水平理解，对生态和水文建模社区具有重要意义。

ETBC: A new tool for assessing nitrogen saturation status in forests? Mass-independent oxygen isotopes of nitrateEmily M. Elliott, Principal InvestigatorUniversity of PittsburghPROJECT ABSTRACTAs U.S. forests continue to age, nitrate leaching from forests could become an increasingly important contributor to surface water quality impairment. This project establishes the use of a mass-independent oxygen isotope tracer of atmospheric nitrate as an empirical tool for quantifying export of atmospheric nitrate from forested watersheds and for assessing the nitrogen saturation status of watersheds lacking long-term water quality data. The objectives of research include the following: 1) development of a new empirical tool for accurately quantifying atmospheric nitrate export from watersheds and associated N saturation status; 2) an intra-watershed assessment of spatial heterogeneity of nitrate sources in soil water leachate in a N saturated system; and 3) a characterization of high resolution temporal dynamics of nitrate sources to streamwater during episodic acidification stormflows. This research is expected to provide an unparalleled ability to assess the impacts of chronic N deposition at a much higher spatial resolution than previously possible, transforming our understanding of the interactions between atmospheric deposition, ecosystem health and water quality. Additionally, the project will generate new insight into how forest management strategies can influence atmospheric N export with important implications for managing water quality in sensitive systems and improve our process-level understanding of spatial and temporal variations in atmospheric N export with important implications for the ecological and hydrological modeling communities.