Production of Small Size Fuelwood from the Thining of Eucalyptus camaldulensis Dehnh. Plantation

Abstract

                The study on production of small size fuelwood from thining of Eucalyptus camaldulensis Dehnh. plantation was conducted at Ratchaburi Forest Experiment Station, Amphoe Muang, Ratchaburi Province, from June 1984 to June 1985 by selecting sample plots of 3 – year – old E. camaldulensis plantation with 1 x 1, 1 x 2 and 2 x 2 m spacing using 4, 4 and 2 replications respectively. The diameter at 1.30 m from the ground level of each tree was measured. Trees in two out of four plots of 1 x 1 and 1 x 2 m spacing were thinned in alternate rows so the spacing of the tree become 1 x 2 and 2 x 2 m respectively. The diameter at ground level ( D_o ), at 1.30 m from ground level ( D ) and total height ( H ) of the sprouts were recorded after 4, 8 and 12 months of the thinning . Tree biomass was estimated before thinning and 1 year after thinning by allometric relation with D²H as independent variable Sprout biomass (4, 8 and 12 months after thinning ) was estimated by allometric relation with D²H as independent variable. Tree biomass increment of each plot was analysed, whereas biomass of the thinned trees was calculated. Small size fuelwood production from thinning and from coppice, the duration which biomass of the sprout and the unthinned tree would equal that of the thinned, the suitable stump size which can produce good coppice, percentage of survival sprout and the income from production of small size fuelwood after the third and fourth year were studied.

                The results of the study showed that the biomass of 3 an d4 year – old E. camaldulensis in the 1x2 m control plot was the greatest followed by those in the 1x1 and 2x2 m control plot respectively. The increment of thinned plots in 1 x1 and 1 x 2 m was higher than that of the control. The increment of plot under thinning alternative I ( 1 x 1→1 x 2 m ) was higher than that of plot under thinning alternative II (1 x 1→2 x 2 m ). Larger stumps produced better coppice than smalled ones. The growth rate of the sprout in the plots under thinning alternative I and II showed no difference after 4 months of thinning but after 8 and 12 months the growth rate of plot under thinning alternative I was higher. The survival percentage of the erect sprout in plot under thinning alternative I was higher than that of plot under thinning alternative II but the creeping sprout of the two plots would dieback after 4 months. After thinning, sprouts and remaining trees in the plot under thinning alternative I produced biomass more rapidly than those in the plot under thinning alternative II.

                 Procution of small size fuelwood from thinning after 3 years old in the plots under thinning alternative I and II were 165,579 and 11,724 bundle/hectare, of equal to the income of 2,652.63 an d1875.81 baht/rai. After the fourth year, production of plots under thinning alternative I and II were 40,859 and 25,020 bundle/hectare or equal to the income of 6,537.44 and 4,003.21 baht/rai by excluding the operational expenses.