Crescimento e produtividade da Mimosa tenuiflora (Willd.) Poir. (jurema-preta) em plantios homogêneos aos 7 anos de idade

Abstract

Due to the socioeconomic relevance of firewood and charcoal for the Northeast region, investments in research and generation of information on the silviculture of suitable species are necessary to meet the regional energy needs. Thus, this work aimed to evaluate the growth and determine the productivity of jurema-preta (Mimosa tenuiflora) in homogeneous plantations at 7 years of age located in Macaíba-RN. The experimental planting evaluated in this study was divided into two plots with different planting spacings: Plot 1 (2 m x 2 m) and Plot 2 (3 m x 3 m). Planting growth was evaluated by measuring the variables dendrometric DAP (diameter at 1.30 m from the ground), DNB (diameter at the base) and total height. The inclusion criterion for the individuals to be evaluated was DAP ≥ 2.0 cm. The mean values of DNB found for the jurema-preta, at 7 years of age, in Plots 1 and 2 were, respectively, 5.9 and 7.8 cm. The variable DAP had an average of 3.6 cm in the 2 m x 2 m planting spacing and an average of 3.8 cm in the 3 m x 3 m planting spacing. The height of the individuals presented an average of 4.0 cm and 3.8 cm, for Plots 1 and 2. The estimated productivity was 159.13 st/ha and 139.65 st/ha for Plot 1 and 2, respectively . The planting, at 7 years of age, presented productivity superior to the stock of wood from native vegetation of the Caatinga, showing the potential of this species for the region. The data suggest that the Average Annual Increment (MAI) of Plot 2 (3 x 3 m) is approaching its maximum point at 7 years of age, which defines the technical cutting age. In Plot 1 (2 x 2 m), the cutting age has already occurred.