THE SCHUTZ INDEX OF INTERINDIVIDUAL COMPE TITION

Schutz index is a distance-dependant competition index that evaluates the tree growth by taking into account both the horizontal (distance b etween crown radii) and vertical competition (height difference). Rela tive to most of the distance-dependant indices, Schutz index considers crown radius instead of diameter at breast height. Two black spruce s tands of regular and irregular structure are chosen to analyze the beh aviour and the performance of the index. Relative to Arney and Monseru d-Ek indices that also use crown radius, Schutz index satisfyingly est imates basal area and volume increments. The horizontal component of t he index, however, is not indispensable for estimating height incremen t. Because of its particular formulation, Schutz index is highly conve nient for determining competitor trees in forest.