SITE INDEX CURVES FOR SITE QUALITY ASSESSMENT OF NAUCLEA DIDERRICHII MONOCULTURE PLANTATIONS IN OMO FOREST RESERVE, NIGERIA

0.542 . The proportional or guide curve method was adopted in constructing the sites curves, with the chosen model as the average guide curve. Based on this curve, the plantation was divided into five site quality classes, A to E, with class A representing the best site while class E, the poorest. Result showed that a 30-year-old Opepe plantation in the study area attained average dominant height of about 30, 26 and 22 m on site quality classes A, C and E respectively. The site index curve was used as a guide to recommend the time of first and subsequent thinning operations in Opepe plantations as well as suitable sites for future plantations.