title: Nitrogen saturation induced during winter by experimental NH4NO3 addition to a forested catchment.
abstract: To investigate the potential risk of 'nitrogen saturation' in Scandinavian boreal forests, the authors are experimentally adding 30-50 kg N ha(-1) year(-1) as NH4NO3 in precipitation to an entire 0.52-ha 80-year-old spruce forested catchment at Gårdsjön, near Gothenburg on the Swedish west coast. NO3 concentrations in runoff increased from 0 to about 7 microeq liter(-1) (maximum pulse of 43 microeq liter(-1)). The increase occurred in winter; during the April-October growing season, NO3 concentrations were very low. The speed of the response suggests that these forests are already close to saturation.
authors.affiliation: Swedish Environmental Research Institute (IVL), Department of Ecology and Environmental Research, Box 47086,40258 Gothenburg, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Hultberg
authors.forename: N B
authors.initials: NB
authors.lastname: Dise
authors.forename: R F
authors.initials: RF
authors.lastname: Wright
authors.forename: I
authors.initials: I
authors.lastname: Andersson
authors.forename: U
authors.initials: U
authors.lastname: Nyström