Visual Tree Assessment

(Mattheck and Breloer 1994)

Claus Mattheck introduced a biomechanically based system of Visual Tree Assessment (VTA), the basis of which is the identification of symptoms produced by a tree in reaction to a weak spot, or area of mechanical stress.

VTA is a non-invasive method of examining the health and structural condition of individual trees.

It has become the standard approach for surveying trees.  By visually examining a tree, an arboriculturalist can gather information on the condition of its roots, trunk, main branch structure, crown, buds and leaves to make an assessment  and draw conclusions about general condition, health and vitality.

It is a systematic approach, which directs the arboriculturalist through a procedure from biological and routine observations to analysis, using their understanding of failure criteria.

In any inspection regarding tree health or safety, an arboriculturalist will look for biological signs, such as undersized leaves, discoloured foliage, dead branches, large or numerous cankers and fungal fruiting bodies.  They will be able to recognize the significance of these observations by comparing them with the typical growth patterns and appearance of the tree involved.

They will also look at the tree for signs of structural weakness or for a change in growth patterns that may indicate defects.  If mechanical weakness is suspected, there may be a need for more investigation using specialist decay detection and measuring equipment.