title: Assessment of ozone effects on nitrate export from Hubbard Brook Watershed 6.
abstract: The impact of the air pollution ozone on soil N dynamics and temporal and spatial patterns of streamflow nitrate flux at the Hubbard Brook Experimental Forest Watershed 6 during the 1964-1994 period was assessed using aggregated (one-cell) and spatially explicit (208-cell) versions of the SImple NItrogen Cycle (SINIC) model. Simulated ozone effects included reductions in stomatal conductance and plant N demand. Model uncertainty was evaluated using Monte Carlo simulations. Ambient ozone was estimated to cause an additional 0.042 gN/m2 per year of nitrate export, 12% of the mean annual streamflow nitrate flux. The 95% credible interval of this estimate was 0.002-0.083 gN/m2 per year, or 0.72-27.3% of the annual flux. The large uncertainty in this estimate suggests that it may be difficult to identify ozone effects on nitrate export utilizing long term data from a single site.
authors.affiliation: Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, NY 14853, USA. bohong@mailbox.syr.edu
authors.forename: Bongghi
authors.initials: B
authors.lastname: Hong
authors.forename: David A
authors.initials: DA
authors.lastname: Weinstein
authors.forename: Dennis P
authors.initials: DP
authors.lastname: Swaney
mesh_terms: D000393:Air Pollutants; D003198:Computer Simulation; D004784:Environmental Monitoring / Q000379:methods; D016468:Forestry; D005618:Fresh Water; D015233:Models, Statistical; D009518:New York; D009566:Nitrates; D010083:Oxidants, Photochemical; D010126:Ozone; D012989:Soil Pollutants; D013995:Time; D014872:Water Movements; D014874:Water Pollutants, Chemical
chemical_list: D000393:Air Pollutants; D009566:Nitrates; D010083:Oxidants, Photochemical; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D010126:Ozone