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International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests 

Chair: Mr. Marco Ferretti
Head of Programme Co-ordinating Centre: Mr. Kai Schwärzel

The International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) was launched in 1985 in response to wide public and political concern over extensive forest damage that had been observed in Europe in the beginning of the 1980s. The objectives of ICP Forests are to monitor the effects of anthropogenic (in particular air pollution) and natural stress factors on the condition and development of forest ecosystems across Europe and beyond, and to contribute to a better understanding of cause-effect relationships in forest ecosystem functioning.

Since 1986, ICP Forests has conducted an annual transnational survey of forest tree crown condition and tree damage causes, until 2006 in close cooperation with the European Commission (EC). This annual large-scale Level I monitoring is conducted on a uniform 16 km x 16 km transnational grid of sample plots across Europe. Together with soil and foliar analyses on parts of the Level I plots, the Level I monitoring documents the development of forest condition at the transnational rather than the national scale. In 2019, around 110,000 sample trees on more than 5,850 sample plots were assessed across Europe.

In 1994, an additional network for intensive forest monitoring (Level II) was established on more than 620 permanent observation plots across Europe (as at 2018) in order to contribute to a better understanding of the effects of air pollution and other factors on forest ecosystems. The intensive Level II forest monitoring includes the assessment of crown condition and damage causes, the chemical composition of foliage and soils, tree growth, biodiversity, atmospheric deposition, ambient air quality (incl. ozone concentrations and symptoms), phenology, and meteorological variables. The data from the Level I and Level II monitoring are stored and maintained at the Programme Coordinating Centre of ICP Forests and available upon request.

The programme is planned and coordinated by a Task Force under the leadership of Germany, with its Programme Coordinating Centre located at the Thünen Institute of Forest Ecosystems in Eberswalde, Germany. There are currently 42 countries participating in ICP Forests.
The revised mandate for ICP Forests can be found in EB decision 2019/16.
Further information is available from the Programme Centre.

Reports of ICP Forests

Report of ICP Forests, 2023

Report of ICP Forests, 2022

Report of ICP Forests, 2021

Report of ICP Forests, 2020

Report of ICP Forests, 2019