Predicting Individual Tree Heights In Gmelina arborea (Roxb) Plantations Of Ukpon River Forest Reserve, Cross River State, Nigeria

Abstract

Gmelina arborea plantations were established in Nigeria mainly to provide raw materials for pulp and papermaking. The species is now being converted for timber production as a result of the failure of the mills to utilize them. Sound planning for the utilization of this resource requires availability of adequate growth and yield information. Tree Height estimates were made based on data collection from 140 trees in the 21 – 35 year-old G. arborea plantations in Ukpon River Forest Reserve, Cross River State, Nigeria. The selected equation involved a logarithmic (transformed) height model with stands age, total number of trees per hectare, site index and diameter ay breast height (dbh) as predictor variables. Paired ‘t\' statistics (0.25 at p < 0.05) and an estimated bias of 0.9% indicate that the selected tree height model can be adequately used for predicting tree height in G. arborea plantations of Ukpon River Forest Reserve.

Keywords: Tree height model, Timber production, Ukpon River Forest Reserve.

Journal of Agriculture, Forestry and the Social Sciences Vol. 4 (2) 2006: pp. 107-108