Green Weight, Taper & Volume Equations for Loblolly Pine in Oklahoma, USA

Abstract

Data from 158 loblolly pine (Pinus taeda L.) trees located in industrial plantations in the Ouachita Mountains of southeastern Oklahoma, USA were collected and used to develop taper, merchantable volume and merchantable green weight equations. These plantations are located near the north-west extreme but outside of the natural range of loblolly pine. Oklahoma loblolly pine was compared to predictions from previously published equations for loblolly pine’s native range in order to evaluate whether differences for taper, volume and green weight characteristics existed between these populations. This study indicates that Oklahoma loblolly pine has less merchantable green weight and volume for a given dbh, total height and merchantability limit than predicted by some well-known models. Diameter for a given height was also different. Since differences were observed the exponential merchantable diameter ratio equation, a new merchantable height based model and a new taper equation, which was derived from the merchantable height based model, were selected from among several well-known models for prediction of merchantable green weights and volumes. This work provides equations that have good predictive ability for trees across a wide range of conditions present in this region of Oklahoma, and which should work well in neighboring areas in the Ouachita Mountain region.