Responses of forest ecosystems in Europe to decreasing nitrogen deposition - Chapter 13

Cambridge

2024

227-245

Sonderdruck

13215S

40004533

Tree crown condition provides an aggregated measure of tree vitality. Studies evaluating spatial and temporal patterns of crown condition based on long-term monitoring data come to different conclusions regarding the relative importance and direction of the effect of N deposition. To our knowledge, no large-scale response to decreasing N deposition has been reported. N deposition can have both a positive (fertilizing) effect on tree vitality (crown condition) but also contribute to a range of adverse effects. We assume that the high complexity and spatio-temporal variability of these mechanisms is partly causing the difficulty to detect signals of decreasing N deposition in tree vitality. In addition, factors like site, stand age, drought, and frost can have strong effects on vitality independent of N deposition (e.g., Eickenscheidt et al., 2016; Klap et al., 2000).