title: Ecologically implausible carbon response?
abstract: Magnani et al. present a very strong correlation between mean lifetime net ecosystem production (NEP, defined as the net rate of carbon (C) accumulation in ecosystems) and wet nitrogen (N) deposition. For their data in the range 4.9-9.8 kg N ha(-1) yr(-1), on which the correlation largely depends, the response is approximately 725 kg C per kg N in wet deposition. According to the authors, the maximum N wet deposition level of 9.8 kg N ha(-1) yr(-1) is equivalent to a total deposition of 15 kg N ha(-1 )yr(-1), implying a net sequestration near 470 kg C per kg N of total deposition. We question the ecological plausibility of the relationship and show, from a multi-factor analysis of European forest measurements, how interactions with site productivity and environment imply a much smaller NEP response to N deposition.
authors.affiliation: Alterra, Wageningen University and Research Centre, PO Box 47, 6700 AA Wageningen, The Netherlands. wim.devries@wur.nl
authors.forename: Wim
authors.initials: W
authors.lastname: de Vries
authors.forename: Svein
authors.initials: S
authors.lastname: Solberg
authors.forename: Matthias
authors.initials: M
authors.lastname: Dobbertin
authors.forename: Hubert
authors.initials: H
authors.lastname: Sterba
authors.forename: Daniel
authors.initials: D
authors.lastname: Laubhahn
authors.forename: Gert Jan
authors.initials: GJ
authors.lastname: Reinds
authors.forename: Gert-Jan
authors.initials: GJ
authors.lastname: Nabuurs
authors.forename: Per
authors.initials: P
authors.lastname: Gundersen
authors.forename: Mark A
authors.initials: MA
authors.lastname: Sutton
mesh_terms: D002244:Carbon / Q000378:metabolism*; D004463:Ecology; D017753:Ecosystem; D005060:Europe; D009584:Nitrogen / Q000378:metabolism; D014197:Trees / Q000378:metabolism
chemical_list: D002244:Carbon; D009584:Nitrogen