Carbon–nitrogen interactions in European forests and semi-natural vegetation – Part 2: Untangling climatic, edaphic, management and nitrogen deposition effects on carbon sequestration potentials

作者：Christophe R. Flechard, Marcel van Oijen, David Cameron, W. de Vries, Andreas Ibrom, Nina C. Buchmann, Nancy B. Dise, Ivan August Janssens, Johan Neirynck, Leonardo Montagnani, Andrej Varlagin, Denis Loustau, Arnaud Legout, Klaudia Ziemblińska, Marc Aubinet, Mika Aurela, Bogdan Heronim Chojnicki, Julia Drewer, Werner Eugster, André‐Jean Francez, Radosław Juszczak, Barbara Kitzler, Werner L. Kutsch, Annalea Lohila, Bernard Longdoz, Gioṙgio Matteucci, Virginie Moreaux, A. Neftel, Janusz Olejnik, María José Sanz, Jan Siemens, Timo Vesala, Caroline Vincke, Eiko Nemitz, Sophie Zechmeister‐Boltenstern, Klaus Butterbach‐Bahl, Ute Skiba, Mark A. Sutton · 发表于：Biogeosciences · 年份：2020 · DOI：10.5194/bg-17-1621-2020 · 被引用次数：37 · 研究领域：Plant Water Relations and Carbon Dynamics、Plant responses to elevated CO2、Forest ecology and management

The effects of atmospheric nitrogen deposition ( N dep ) on carbon (C) sequestration in forests have often been assessed by relating differences in productivity to spatial variations of N dep across a large geographic domain. These correlations generally suffer from covariation of other confounding variables related to climate and other growth-limiting factors, as well as large uncertainties in total (dry + wet) reactive nitrogen ( N r ) deposition. We propose a methodology for untangling the effects of N dep from those of meteorological variables, soil water retention capacity and stand age, using a mechanistic forest growth model in combination with eddy covariance CO 2 exchange fluxes from a Europe-wide network of 22 forest flux towers. Total N r deposition rates were estimated from local measurements as far as possible. The forest data were compared with data from natural or semi-natural, non-woody vegetation sites. The response of forest net ecosystem productivity to nitrogen deposition (dNEP ∕ d N dep ) was estimated after accounting for the effects on gross primary productivity (GPP) of the co-correlates by means of a meta-modelling standardization procedure, which resulted in a reduction by a factor of about 2 of the uncorrected, apparent dGPP ∕ d N dep value. This model-enhanced analysis of the C and N dep flux observations at the scale of the European network suggests a mean overall dNEP ∕ d N dep response of forest lifetime C sequestration to N dep of the order of ...