VOLUME EQUATIONS AND THEIR VALIDATION FOR IRRIGATED PLANTATIONS OF <em>EUCALYPTUS</em> <em>CAMALDULENSIS</em> IN THE HOT DESERT OF INDIA

Abstract

Six volume equations using diameter or combining diameter with height as predictors, were compared on the basis of fit and validation statistics using data collected from Eucalyptus camaldulensis stands in Indira Gandhi Nahar Pariyojana (IGNP) area of Rajasthan State in India. An equation that fits very well to a data set may not necessarily be the best when applied to another data set collected from the same population. The contrasting results obtained between model fitting and validation emphasise the need for model validation as an important step in the model construction process. The combined variable equation produced the best volume estimates and hence has been recommended for use in estimating total wood volume of E. camaldulensis in the study area.