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 effects of anthropogenic (in particular air pollution) and natural stress factors on the condition and development of forest ecosystems in Europe, and to contribute to a better understanding of cause-effect relationships in forest ecosystem functioning in various parts of Europe.
Since 1986, ICP Forests has conducted an annual transnational survey of forest condition in Europe, from 1991 in close cooperation with the European Commission (EC). This transnational survey aims to document the development of forest condition at the European level rather than at the national scale. This is accomplished by means of annual large-scale monitoring of tree vitality (6,000 sample plots with about 130,000 sample trees) and a number of site parameters on a uniform 16 km x 16 km transnational grid of sample plots (known as "level I" monitoring). In addition to tree vitality surveys, soil and foliar analyses are performed on parts of these level I plots. In order to contribute to a better understanding of air pollution and other factors which may influence forest ecosystems, a programme for intensive and continuous monitoring of forest ecosystems (level II) has been implemented. For this purpose, 860 permanent observation plots for intensive monitoring of forest ecosystems have been established across Europe. The intensive monitoring includes the assessment of crown condition, increment and chemical composition of foliage and soils on all plots. The data from the level II intensive monitoring plots are currently stored and maintained at the Programme Coordinating Centre.
The programme is planned and coordinated by a Task Force under the leadership of Germany, with the cooperation of a Programme Coordinating Centre (at the Federal Research Centre for Forestry and Forest Products, in Hamburg, Germany). There are currently 42 countries participating in the work.
Further information is available from the Programme Centre.