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

ETBC：评估森林氮饱和状态的新工具——与质量无关的硝酸盐 D17O

• 批准号: 0910521
• 负责人: Emily Elliott
• 金额: $ 51.5万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0910521&HistoricalAwards=false
• 关键词: ETBC; new; tool; assessing; nitrogen

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.

ETBC：一种评估森林氮饱和状态的新工具？随着美国森林的不断老化，森林中硝酸盐的浸出可能成为地表水质量损害的一个越来越重要的因素。该项目建立了使用与质量无关的大气硝酸盐氧同位素示踪剂作为量化森林流域大气硝酸盐输出和评估缺乏长期水质数据的流域氮饱和状态的经验工具。研究目标包括：1)建立准确定量流域大气硝酸盐输出及相关氮饱和状态的新经验工具；2)流域内氮饱和系统土壤渗滤液中硝酸盐源空间异质性评价；3)幕式酸化暴雨过程中硝酸盐源对水流的高分辨率时间动态特征。这项研究有望提供无与伦比的能力，以比以前更高的空间分辨率评估慢性氮沉降的影响，改变我们对大气沉降、生态系统健康和水质之间相互作用的理解。此外，该项目将对森林管理策略如何影响大气N输出产生新的见解，对敏感系统的水质管理具有重要意义，并提高我们对大气N输出时空变化的过程级理解，对生态和水文建模社区具有重要意义。