Over the last 30 years ICP Forests has developed into one of the world's largest biomonitoring networks. Its results provide information on forest condition, air pollution, climate change, and biodiversity.

The objectives of the Programme are

1. to provide a periodic overview on the spatial and temporal variation of forest condition in relation to anthropogenic and natural stress factors (in particular air pollution) by means of European-wide and national large-scale representative monitoring on a systematic network (Level I);
   
   
2. to gain a better understanding of the cause-effect relationships between the condition of forest ecosystems and anthropogenic as well as natural stress factors (in particular air pollution) by means of intensive monitoring on a number of selected permanent observation plots spread over Europe and to study the development of important forest ecosystems in Europe (Level II).