Bosvitaliteitsinventaris 2022. Resultaten uit het bosvitaliteitsmeetnet (Level 1)

The Flemish forest vitality inventory indicates that just over a quarter of the trees in our monitoring network are damaged (26.5%). We consider a tree damaged when more than 25% of the leaves are missing. This damage can be in the form of leaf loss, but also by death of shoots, twigs or branches. In extreme cases, the entire tree dies.

In 2022, we inventoried 1486 trees in 78 network measurement sites. The species with the highest percentage of damaged trees were Quercus robur and Corsican pine with 35.7% and 39.3% damaged trees, respectively.

Almost all tree species showed deteriorating health conditions. Weather conditions in 2022 contrasted with those of 2021. Prolonged drought caused discolouration and early leaf loss. Storms caused branches to break off or trees to blow over. In Quercus robur, increased insect predation caused higher leaf loss rates.

Nitrogen deposition is a persistent problem and climate change is adding stress to nature. Mild winters and hot summers promote infestations by fungi and insects. Furthermore, careless management and unfavourable growing sites can adversely affect the health of trees. New invasive exotic species cause damage in a very short time, such as Hymenoscyphus fraxineus, a fungus that causes ash disease.