Tree nutrition is increasingly imbalanced in European forests

Atmospheric deposition gradually increased the availability of nitrogen (N) in forest ecosystems but availability of other elements such as phosphorus (P) remains at the same level. Foliar N/P ratios present a useful tool to assess the effects of these changes to forest trees.

Foliar nutrient data from the ICP Forests intensive monitoring sites across Europe show an increase in sites with N/P ratios above limit values since the 1990s. Currently, 30% of the reviewed sites show imbalances in foliar N/P ratios. The detected nutrient imbalances may affect the ability of forests to mitigate and adapt to climate change.