Work Report of the Institute for World Forestry 2011/1
The study presents results of the 2010 forest health and vitality survey carried out on the representative net of Level I plots of ICP Forests and the FutMon project. The survey was based on over 7 500 plots and 145 000 trees in 33 participating countries, including 26 EU member states. It was thus the most comprehensive survey that has ever been carried out on the Level I network. Defoliation results show slightly higher mean defoliation for broadleaves as compared to the conifers assessed. Deciduous temperate oaks had the highest mean defoliation (24.8%), followed by the south European tree species groups. Picea abies and Pinus sylvestris showed lowest mean defoliation with 17.0% and 17.4% respectively. The Mediterranean coast in southern France and northern Spain was a hot spot with specifically high defoliation in several species groups. Over the last five years, temporal defoliation trends show some recuperation for evergreen oaks and a continuously increasing defoliation of Pinus sylvestris. For the other species/-goups there is no pronounced trend in the most recent years. After the heat and drought in central Europe in 2003 defoliation clearly increased for most tree species. This points to the value of the data as basis of an early warning system for tree health under changing environmental conditons. For the first time, forest damage assessments were evaluated based on newly introduced assessments that had started in 2005. In 2010, damage causes were assessed with harmonized methods on 6 413 plots in 32 different countries across Europe. Insects and fungi were the most widespread agents occurring on 27% and 15% of the trees within the survey. The occurrence of these factors shows clear regional trends like plots with high insect occurrence in north-eastern Spain, Italy or Hungary or high occurrence of trees with fungal infestations in Estonia.