Stow Craig A, Walker John T, Cardoch Lynette, Spence Porche, Geron Chris
Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina 29208, USA.
Environ Sci Technol. 2005 Sep 15;39(18):6999-7004. doi: 10.1021/es0500355.
We present N2O emission data from 11 sites in the Neuse River watershed. Emissions were measured using a static surface enclosure technique deployed on eight sites on the main river channel and three tributary sites. Ancillary data collected included dissolved oxygen, nitrate, total nitrogen, ammonium, dissolved organic carbon, total phosphorus, and temperature. Analysis using standard linear models, and classification and regression trees (CART), indicated nitrate to be the primary driving variable associated with N2O emission, although dissolved organic carbon concentration and water temperature were positively related with N2O emission as well. Relationships between nitrate concentration and N2O emission were consistent with those found in previous studies, although the data presented here represent the lower end of the range for both variables among published studies. Using our measured N2O emission rates along with literature values for the ratio of nitrogen gas to N2O produced during denitrification, we estimate N loss via denitrification in the Neuse River is approximately 17% of the annual N load delivered to the estuary.
我们展示了纽斯河流域11个地点的一氧化二氮排放数据。排放是通过在主河道的8个地点和3个支流地点采用静态地表封闭技术进行测量的。收集的辅助数据包括溶解氧、硝酸盐、总氮、铵、溶解有机碳、总磷和温度。使用标准线性模型以及分类与回归树（CART）进行分析表明，硝酸盐是与一氧化二氮排放相关的主要驱动变量，尽管溶解有机碳浓度和水温也与一氧化二氮排放呈正相关。硝酸盐浓度与一氧化二氮排放之间的关系与先前研究中发现的关系一致，尽管此处呈现的数据代表了已发表研究中这两个变量范围的下限。利用我们测量的一氧化二氮排放速率以及反硝化过程中产生的氮气与一氧化二氮比例的文献值，我们估计纽斯河通过反硝化作用造成的氮损失约占输送到河口的年氮负荷的17%。
