Modeling Number of Trees per Hectare Dynamics for Uneven-Aged, Mixed-Species Stands Using the Copula Approach

For the monitoring and management of forest resources, main index is stand volume, which determined on basis tree diameter, height, number trees per hectare three-dimensional distribution. The development in dynamic driven by random phenomena. In this study, potentially available area, height are described mixed-effect parameters Gompertz-type diffusion process. A normal copula function used to connect a distribution its one-dimensional margins. newly developed model was illustrated using empirical data from 53 permanent experimental plots (measured for seven cycles), were characterized as follows: pine forests (Pinus sylvestris), 63.8%; spruce (Picea abies), 30.2%; silver birch (Betula pendula Roth Betula pubescens Ehrh.), 5.8%; others, 0.2%. An analysis diameter growth, including current mean increments inflection points, presented. models change with age presented probabilistic density functions solutions stochastic differential equations function. dynamics visualized graphically, goodness fit evaluated standard statistical measures.