General q-exponential Model for Tree Height, Volume and Stem Profile

Abstract

Two new q-exponential height and q-exponential segmented taper models were developed using qexponential function. Four height models, six stem volume models, and three taper models were compared to the observed values of height, stem volume and diameter outside bark. The performance statistics of the height, volume and taper equations included four fit statistics: mean bias, mean absolute bias, mean percentage of absolute bias and a coefficient of determination. Data used in this study came from stem analysis on 1925 pine trees. Results show that the q-exponential models were superior to the other used models in predicting height, volume and diameter outside bark. The results are implemented in the symbolic computational language MAPLE.