Desenvolvimento de um modelo para manejo sustentado do Cerrado

Abstract

A phytosociological survey of trees and shrubs as well as a soil survey were accomplished in a continuous area of cerrado, property of Empresa Mannesmamm Florestal Ltda, located at 17o02’S and 45o50’W, at 575m of altitude, municipality of Brasilândia, at the northeast of Minas Gerais state. The region’s climate is Köppen’s Aw type. The preliminary surveys were aimed at detecting possible strata for the implementation of sustainable management options, utilizing Meyer’s concepts of balanced forest. The phytosociological survey utilized the point-centred quarter method with points located in 42 transects, totalizing 1404 points with a distance of 50m among themselves. A total of 5616 individuals were sampled, distributed in 41 families, 75 genera and 97 species. For the characterization of the existent soils, a semi-detailed survey of the soil types was carried out and the following types were found: Cambisol, Red-yellow Ferralsol and Dark Red Ferralsol. Once specified the soils, it was made a stratification of the whole area, totalizing 10 strata, which were: Cambisol, four repetitions of Red-yellow Ferrasol and five repetitions of Dark Red Ferrasol. The resulting data of the phytosociological survey associated to those coming from the chemical and granulometric analyses from all ten strata, allowed carrying multivariate analyses through PCA (Principal Components Analysis), DCA (Detendring Correspondence Analysis) and CCA (Canonical Correspondence Analyses). These analysis indicated little variation for the vegetation, without any significant difference among the ten strata. Therefore, it was implanted three blocks totalizing 30 ha (200 x 500m each), including 10 treatments of 100 x 100m, in an area of Dark Red Ferrasol where the vegetation was more homogeneous. In each treatment it was delimited a plot of 1800 m2 (30 x 60m). Therefore, for all 30 plots all specified individuals were measured. From the collected data it was possible to accomplish management plans, based on Meyer’s concept of balanced forest. The plans were generated by a computer program named SISNAT. A restriction was determined that only the species that showed relative density larger or equal to 1% would be included on the management proposals. Even so, for each proposal the pattern of spacial distribuition was determined for all species present.