Growth Variation of Heartwood and Sapwood of Teak( Tectona grandis) Plantations at Different Ages

【Objective】 The growth and variation characteristics of heartwood and sapwood,ring number of heartwood,and height of heartwood in different-aged teak( Tectona grandis) plantations in Daqing mountain of Guangxi were investigated,so as to provide scientific basis and basic data for understanding the developmental characteristics of heartwood,predicting heartwood quantity and efficiently cultivating high-quality and large-diameter teak target trees in this region.【Method】 Average trees from 10,18,31 and 41-year-old teak plantations in Daqing mountain of Guangxi province were selected to analyze variation of heartwood and sapwood among orientations and among individual trees using variance analysis,and the regression model between amount of heartwood and sapwood,cross-sectional diameter,and total number of annual rings were fitted by curve estimation method to study the growth variation of teak heartwood and sapwood.【Result】The heartwood radius of teak trees was the largest in the north direction,while the sapwoo