Ferretti M, Calderisi M, Marchetto A, Waldner P, Thimonier A, Jonard M, Cools N, Rautio P, Clarke N, Hansen K, Merilä P, Potocic N (2015) Variables related to nitrogen deposition improve defoliation models for European forests. Annals of Forest Science, 72 (7): 897-906. [10.1007/s13595-014-0445-6]


Nitrogen deposition;Defoliation;ICP Forests;Europe


Context;Nitrogen (N) deposition has increased in the northern hemisphere because of anthropogenic-related emission of N compounds. Increased N availability may have an adverse impact on forest sustainability.;Aims;This study aims to test the importance of throughfall N (Nthr) deposition in explaining the variability of the frequency of trees with defoliation >25 % (F 25), an indicator of forest condition.;Methods;A pan-European data set (71 plots) with enhanced quality control was considered. The additive effect of Nthr-related predictors (identified conceptually and by rank correlation) in explaining F 25 was investigated by partial least square regression in comparison with a reference model based on site, stand, management and climate data. Reported damage to foliage, Nthr deposition, foliar N ratios and mineral top-soil variables were added stepwise to the reference model.;Results;N-related variables improved defoliation models. Higher Nthr deposition led to higher F 25 for beech and Norway spruce, while the effect was opposite for Scots pine. Higher foliar N ratios led to higher F 25 for all species.;Conclusion;Nthr deposition, damage to foliage, foliar N/P, N/Ca, N/Mg, N/K, top-soil pH, C/N and exchangeable base cation resulted important factors (although with possible diverse effect) in explaining the variability of F 25 among plots.

LWF Classification

Network: LWF, Sites: Beatenberg;Bettlachstock;Lausanne;Othmarsingen, Category: ISI,