Tachigali vulgaris em plantios homogêneos na Amazônia: parâmetros de crescimento, madeira e carvão vegetal para fins energéticos.

Abstract

The native tree species Tachigali vulgaris has potential for charcoal and firewood production and may be a forestry biomass to support the production from the Eucalyptus species energy plantations. The aim of this research was to evaluate whether different planting spacing, forking and age affect the growth and quality of T. vulgaris wood and charcoal for energy purposes. The study was carried out in a trial of about 6 ha, performed by Embrapa Amazônia Oriental, at the company Jari Celulose S/A, Monte Dourado District, Almeirim municipality, Pará. The experiment was performed in a randomized complete block design, in a split plot scheme, consisting of 3 blocks and 6 spacings. Growth and wood and charcoal quality parameters has been evaluated. The ANOVA found no significant effect of planting spacing on growth, at 8 and 9 years-old, with a range of 168.23 m3 ha-1 and 195.37 m3 ha-1, for the volume with bark, and of 73.04 t ha-1 and 92.19 t ha-1, for the dry wood mass. The wood basic density, at 7 years-old, has changed as function of the spacing (0.443 to 0.529 g cm-3, among the spacings), and of the forking (0.478 g cm-3 and 0.515 g cm-3 to the forked and not forked trees, respectively). Otherwise, at 8.5 years-old, it has been reported effect only of forking, with a range of 0.523 g cm-3 to 0.537 g cm-3 to the forked and not forked trees, respectively. The apparent density at 12% of moisture, analyzed by X-rays densitometry, has been affected only by age with an average of 0.699 g cm-3. The planting spacing and forking had no effect on heartwood/sapwood ratio, on the immediate and elemental chemical composition and on the heating value, with averages of 80.51%, 0.33%, 19.07%, 2.2%, 50.9%, 6.1%, 40.48%, 20.51 MJ/kg and 19.26 MJ/kg, respectively, to VM, Az, FC, N, C, H, O, HHV and LHV. The planting spacing and forking affect the charcoal apparent density and wood specific consumption, being produced, in the forked stems, charcoal of lower density (0.316 g cm-3) and higher wood specific consumption (6.04 m3 of wood/1 ton of charcoal). The carbonization yields in charcoal, pyroligneous liquid and noncondensable gases, immediate chemical composition, heating value, productivity in charcoal mass and annual mean increment in charcoal had not been affect by plating spacing. The findings of this thesis highlight the adoption of wider plating spacing in order to increase the growth, productivity and wood basic density, with no changes on the other wood and charcoal parameters. Therefore, further researches should be evaluating the causes of forking in T. vulgaris trees.