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
CHART UNDER CONSTRUCTION
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 occurrence of forest fires has increased in the last 10 yearss.
Forest area affected by pathogens, k ha
Most forest disease in the Netherlands is caused by Ash dieback: Chalara fraxinea. It has been recorded on Ash since 2010 yet only in recent years the amount of damage it has become obvious. In 2016 the disease is estimated to have damaged 80% of the entire Ash population. Predictions say this number will grow to 90-95% in the near future.
Deforestation is defined as the permanent conversion of forest land to agriculture, grassland, wetland and urban areas. Deforestation covers forest areas where the impacts of disturbance, over-utilisation or changing environmental conditions affect the forest to an extent that it cannot sustain a canopy cover larger than 10 percent.
Deforestation, k ha
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