HYPSOMETRIC EQUATIONS FOR KHAYA SENEGALENSIS (DESR.) A. JUSS

Abstract

Height is important to understand the behavior of a species over time and to assess the quality of the area for timber production which can be measured or estimated. Hypsometric models allow estimating height from tree diameter, reducing forest inventory costs. This research aimed to adjust a hypsometric model for Khaya senegalensis (Desr.) A. Juss., contributing to the study of the species in Brazil. Data were collected in a 9.8 ha stand, located at Rancho São Lucas in the municipality of Lajeado Novo-MA. Thirty-seven permanent circular plots with an area of ​​800 m² were installed and all diameters and heights of individuals in each plot were measured, totaling 721 individuals. Six hypsometric models were selected and adjusted by linear regression. The best equation was selected using the Adjusted Coefficient of Determination (R2adj.), Standard Error of Estimate (Syx%), Adjusted Standard Error of Estimate (SyxAdj.), Mean Percentage Deviation (MDP), F-test, graphical analysis of residuals and weighted value of statistical parameters. The Trorey model ( H=-0.21461+0.98413 (DBH)+-0.02748 (DBH)^2+ε ) and Prodan (H=(DBH)^2/(1.316862+0.769434(DBH)+0.057553(DBH)^2 )) were chosen because they presented the best statistical parameters.