Potencial de crescimento inicial de espécies florestais nativas em plantio puro

Abstract

The study of native species with potential for use in pure plantations, aiming a production of wood, is very important to know about information about administration and illustrations. The objective of this work was to evaluate the growth of 14 native Brazilian forest species, pointing out their potential for use in pure plantations and, through SAS® Statistical Software, to generate mathematical models that represent the growth of the three best species as a function of time. The study area contains 16 native forest species of seminal origin, planted in plots with 36 plants per species, with 6 columns and 6 lines spaced 3m (line) x 2m (plant). Fourteen species were evaluated: Açoita-cavalo, Angico vermelho, Canafístula, Canjerana, Cabreúva, Caroba, Grápia, Guajuvira, Ipê- oxo, Louro-pardo, Marmeleiro, Pau-marfim, Peroba e Timbaúva. The evaluations were carried out at 2, 7, 12, 24, 43 and 72 months of age from the implementation of the experiment and the qualitative variables evaluated were stem tortuosity and plant vigor. The quantitative variables measured in the field were: lap diameter (DC), diameter at breast height (DAP), total height (H) and two cup diameters (Dcopa) equidistant 90 ° from each other, later used to calculate the area of cup (AC). Mean monthly increment (Imm) was calculated for the variables DC, DAP, H and AC. About the experimental design, all trees of each species were analyzed each plant being considered a sample unit. The different species were compared by the Duncan averages comparison test (1% probability), for DAP, H and AC, in order to know which species presented the highest growth. The mathematical modeling for growth in H and AC of the three best species was calculated by SAS® University Edition statistical software. After adjusting the equations, the covariance analysis was performed to verify the influence of the variables vigor and tortuosity of the plants on growth in H and AC as a function of age. Açoita-cavalo presented the highest mean DC at 24 months (14.13 cm). For DAP, H and AC the three species that presented the best averages were Canafístula, Canjerana and Angico-vermelho. For these, the equations that best estimate the growth were the radical, logarithmic, quadratic equations and the nonlinear model of Richards. Regarding the influence of the qualitative variables, the covariance test showed the need to adjust the equations for different levels of tree vigor and stem tortuosity. Canafístula, Canjerana and Angico-vermelho were the species that showed the greatest growth. Cabreúva, Caroba and Peroba presented lower growth. The qualitative variables influence the growth curve of the plants. The modeling of growth for the Canafístula, Canjerana and Angico-vermelho resulted in equations with good parameters to be used in the estimation of the growth of the species.