MODELING EARLY DEVELOPMENT OF A PLANTED PINE STAND - AN APPLICATION OF OBJECT-ORIENTED PROGRAMMING

This paper describes a model of early development in planted stands of Scots pine (Pinus sylvestris L.) which are composed of seedlings, sprouts (birch), and grass. Development of the stand is controlled by competition for light. The simulations showed that a stand in an early phase of succession is very sensitive to the initial amount of grass present. A small increase in the biomass of grass caused a clear decrease in the densities of pine and birch during the first years after planting. Calculations indicated that pine requires more than a 1.5-m advantage in height to be able to compete successfully with sprouts (birch) in height growth. The model was constructed using object-oriented programming (OOP). The robust framework offered by object-oriented programming is well-suited for constructing simulation models. Comparison of OOP with conventional programming languages showed OOP to be more effective and elastic in modelling than conventional programming languages are.