Criterion 2: Maintenance of forest ecosystem health and vitality

• Generally, the condition of European forests is deteriorating, with increasing mean defoliation of the six most frequent tree species particularly obvious on 18.9% of the plots. • Pests, diseases, wildlife (especially browsing by large ungulates) and grazing by domestic animals, fires and weather extremes such as storms were reported as important causes of damage. The frequency and intensity of storms is increasing over time. A geographical shift in disturbances is also observed. However, the report does not include the most recent developments in forest damage resulting from drought, storms, and barkbeetle outbreaks indicated by some countries after the reporting year of 2015. • Forests in Europe are still exposed to excessive levels of nitrogen deposition and tropospheric ozone – the latter being reported for the first time in the SoEF. Trends over recent decades, however, indicate a reduction in both, reflecting efforts in clean-air policies. • Soil condition revealed distinct North-South gradients in several attributes, most pronounced for soil organic carbon, carbon-to-nitrogen ratio, and soil pH. An apparent increase in total nitrogen was detected between 2009/2012 and 2015 in most of the countries. • Maintenance of forest health and vitality is of high importance in national forest-related policies, as well as in establishing a system of risk prediction and prevention. The implementation of various forest fire prevention activities are the main achievements. The major challenges comprise the necessity to face the increasing risk of damage by harmful organisms and extreme weather events, mass dying of trees and whole stands, and the unclear adaptive potential of tree species to climate change