The rates of diameter increment and age-diameter relationship of Brachylaena huillensis O. Hoffm in semi-decidouos forests of central Kenya

Abstract

It is important to base yield regulations on recruitment of trees and their rates of growth to merchantable sizes. The present study investigated rates of growth of Brachylaena huillensis under its natural growing conditions. The rate~of diameter growth of B. huillensis is slow under natural conditions, ranging from 0·13 to 0·44 cm y - 1 with a mean of O·32 cm y - 1. Various possible factors contributing to the low rates of growth are suggested. The estimated growth rates over various diameter classes led to the construction of an age-diameter curve which indicated that, under natural conditions, a mean diameter of 40 cm dbh may be expected after 100 years, 45 cm after 130 years and 60 cm after about 175 years since regeneration.