Biomass production and characteristics of short rotation plantations of clones of Gmelina arborea in three spacings

摘要

The first attempts to establish energy crops in the tropical region using short rotation species are premised on the utilization of clones for wood production. Therefore, the present study is aimed at examining the growth aspects (survival, diameter and tree height), leaf architecture (leaf area index [LAI], number and angle of the branches and sylleptic branches), biomass production, as well as biomass flow at the age of 24 months of two clones of Gmelina arborea in short rotation crops within three spacings (1.0x1.0 m, 0.75x0.75 m and 1.0x0.5 m). The results showed an increment with age, as the diameter increased from 3.00 cm at six months to 8.0 cm at 24 months, whereas the total height increased from 2.00 m at six months to 10.00 m at 24 months. Clone survival varied from 20 to 60 %, whereas the LAI, branch angle and sylleptic branches increased with age. The differences between clones appeared after 12 months. Biomass production was similar between clones, from 6 ton/ha at six months to 67 ton/ha at 24 months, with clone 2 showing greater biomass flow than clone 1. On the basis of biomass production results and the development of diameter as well as height, clone 1 is recommended for spacing 1.0x1.0 m and clone 2 for spacings 0.75x0.75 m and 1.0x0.5 m.