Enhanced forest growth in combination with relatively high Nitrogen deposition may result in further pedologic and nutritional changes and an even greater destabilisation of forest ecosystems.

Climate change must be considered an ecological and socio-economic threat. We have to support any measures that are combating climate change. It is currently unknown which climate scenario will come true, and therefore very important to maintain the biological diversity of the forest ecosystems for a wide variety of possible development.

The national forest inventory of Switzerland is a large-scale assessment of the condition and changes in Swiss forests. Some of the most important advantages of the NFI are its permanence, the long-term and flexible inventory design, the high data-quality and the compatibility with the damage inventory.

Monitoring of forest health represents an important part of programmes assessing the actual and potential impact of air pollution and climate change on forests. The available information indicates that variation between years is high, indicating that long term time series will be required to identify trends in forest condition.

Two main effects on ectomycorrhizae can be distinguished: direct effects due to a change in the soil chemistry and indirect effects due to a change of the carbohydrate supply from the host trees to the roots.

Wood will have a great importance as renewable raw material. Forest devastation endangers the world's future wood supply. We need a long-term strategy for forestry and forest products industries to protect complete ecological life cycle.

The report summarizes scientific information about forest ecosystems and their relationship to climate change and air pollution, with special emphasis on forests in Europe, North America and China. The contributions reflect the current state of science, but also uncertainties and gaps in scientific knowledge.