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 uses the reactive nature of tree growth to identify mechanical or biological changes, or weaknesses in its structure and physiological condition. A tree is a self-optimising mechanical structure, a generating system which reacts to mechanical and physiological stresses by growing more vigorously to re-inforce weak areas, while depriving less stressed parts. This is described by Claus Mattheck as the axiom of uniform stress. An understanding of the axiom of uniform stress allows an arborist to make informed judgements about the condition of a tree.