MODELING FOREST DYNAMICS - MOVING FROM DESCRIPTION TO EXPLANATION

Descriptive (statistical) models of forest growth cannot cope with changing environmental and management conditions. Since explanatory models attempt to capture the essential eco-physiological processes of forest growth, they are better-suited for the computation of forest dynamics under changing conditions, even when long-term empirical observations are not possible or feasible. Requirements of forest simulation models are analyzed, and essential processes of forest growth which must be represented in structurally valid models are discussed. Steps in obtaining valid but compact tree models for complex forest simulations are outlined, and recent software developments (object-oriented programming) are assessed with respect to their potential for forest simulation models.