Volume Modeling of Individual Trees Using Stochastic Differential Equations and Trivariate Copula

Abstract

A system of stochastic differential equations and trivariate copula density function were used to develop outside-bark stem volume model for Scots pine (Pinus Sylvestris) trees in Lithuania. After fitting the transition probability density functions to outside bark diameter at breast height, total tree height, and total stem volume, a trivariate normal copula distribution model was constructed. Predictions from the volume equation calculated during this research were compared to q-exponential volume equation. The results are implemented in the symbolic computational language MAPLE