Forest ecosystem condition

Major pressures affect the forest and their ecosystems. The European member states record the following forest health indicators in a harmonised way: tree crown condition, soil condition and foliar nutrient content.

Foliar nutrient condition


Tree crown condition, %

Defoliation is defined as needle/leaf loss in the assessable crown as compared to a reference tree. Defoliation is observed regardless of the cause of foliage loss.

Trees are moderately to severely defoliated when defoliation exceeds 25%.


Main disturbances on forest ecosystems

The main disturbances on forests comprise forest fires, diseases, insects and storms.

Forest area affected by fires, k ha

The occurrences of forest fires have varied over the last 20 years with high occurrences in 2000 and 2007


Forest area affected by pathogens, k ha

Between 5 to 10 000 ha of forests are affected by diseases every year.


Forest area affected by insects, k ha

Insect damage has decreased since 2010 but still amount to more than 40 000 ha each year


Forest area affected by severe weather, k ha


Forest fragmentation

Forest fragmentation is breaking large, contiguous forested areas into smaller forest patches, separated by roads, agriculture, utility corridors or other anthropological developments.

Fragmentation is one of many factors that threaten forest health and vitality. Large and intact forest ecosystems are essential to maintaining a good forest condition and biodiversity. Increased fragmentation means that the forest area in the largest patch sizes will decrease and that the small size classes will increase.

Share of different forest patch sizes in 2018, % of total forest cover