Comparative study of the growth form of Tectona grandis (Linn.) plantations planted with four different spacing at Mae-Moh, Lampang

Results of the study are summarized as follows : 1. For all spacings the correlation between diameter at breast height(DBH) and total height(H), crown branching height(HB) and crown length(CL) are hyperbolic, while the correlation between the total height(H) and crown diameter(CD), crown length(CL), crown branching height(HB) and DBH are exponential; slenderness (H/D ratio) and crown sectional area/basal area at breast height (CSA/BA) were found to decrease with the increasing of DBH. 2. Total aboveground biomass and stem volume of Tectona grandis (Linn.) plantation planted with 2x2 m x m spacing was found to be largest being approximately 61.54 ton/ha and 196.12 cubic meter/ha 3x3, 4x4 and 6x6 mxm spacing plantations were found to be next to the former plantation in the magnitude of above ground biomass and stem volume being 23.95 ton/ha and 37.90 cubic meter/ha; 13.75 ton/ha and 22.80 cubic meter/ha; 2.53 ton/ha and 4.43 cubic meter/ha respectively. Stem and branch biomass were found to be large in the order; 2x2 3x3 4x4 4x4 6x6 m x m spacing stands respectively. 3. Stand density was found to be large in the order; 2x2 3x3 4x4 6x6 m x m spacing stands respectively. Mean DBH was found to be large in the order; 4x4 3x3 2x2 6x6 m x m spacing stands respectively. Mean total height was found to be large in the order; 2x2 3x3 4x4 6x6 m x m spacing stands respectively. Mean Basal area was found to be large in the order; 4x4 2x2 3x3 6x6 m x m spacing stands respectively. Mean crown branching height was found to be large in the order; 2x2 3x3 4x4 6x6 m x m spacing stands respectively. Mean crown diameter was found to be large in the order; 4x4 3x3 and 6x6 2x2 m x m spacing stands respectively. Mean crown length was found to be large in the order: 2x2 3x3 4x4 6x6 m x m spacing stands respectively.