title: N2O emissions from streams in the Neuse river watershed, North Carolina.
abstract: 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.
authors.affiliation: Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina 29208, USA. cstow@sc.edu
authors.forename: Craig A
authors.initials: CA
authors.lastname: Stow
authors.forename: John T
authors.initials: JT
authors.lastname: Walker
authors.forename: Lynette
authors.initials: L
authors.lastname: Cardoch
authors.forename: Porche
authors.initials: P
authors.lastname: Spence
authors.forename: Chris
authors.initials: C
authors.lastname: Geron
mesh_terms: D000393:Air Pollutants; D004784:Environmental Monitoring; D016014:Linear Models; D015233:Models, Statistical; D009010:Monte Carlo Method; D009566:Nitrates / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D009585:Nitrogen Dioxide / Q000032:analysis*; D009657:North Carolina; D010100:Oxygen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D012044:Regression Analysis; D045483:Rivers; D013696:Temperature; D014872:Water Movements; D014873:Water Pollutants
chemical_list: D000393:Air Pollutants; D009566:Nitrates; D014873:Water Pollutants; D010758:Phosphorus; D009584:Nitrogen; D009585:Nitrogen Dioxide; D010100:Oxygen