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Types of damage

Abiotic damages

Weather related damages

Damages caused by bad weather.

Damages caused by pollution

Damages caused by a polluting agent (physical or chemical).

Biotic damages


Some wild animals cause damage to trees.


Bacteria are single-celled organims with no true nucleus. They have a single chromosome. There are few pathogenic bacteria that attack trees.


The majority of species described on this site can be found in the section on fungi. Given the large number of species covered, you will have an extra step to go through before you reach the technical fact sheet.


Some plants can cause damage to other plants by encircling and smothering them or by parasitizing them.

Types of damage


Foliar disease characterized by necrotic areas (dead, brown tissue) .


Lesion on the inner live bark of trees that causes a change in colour, bark sagging, and sometimes mortality in affected branches or small trees. Callus formation often occurs on the trunks.

Damage caused by animal


Softening, loss of density and discoloration of wood caused by decomposition.

Root rot

Decomposition of root tissue that can hinder the flow of sap, girdle trees at the root collar and promote windthrow (tree overthrown by the wind).


Disease that often gives rise to orange-coloured pustules, causing leaf drop, witches' broom or cankers.

Witches' broom

Excessive growth of twigs from a single point on a branch. The twigs are erect and compact. Needles are often deformed or of an abnormal colour.

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