Levantamento fitossociológico e estimativa de biomassa aérea de uma área de caatinga com uso de equações alométricas e geotecnologias.

Abstract

The domain of the Caatinga biome covers a considerable area of the Brazilian territory. The predominant vegetation is Caatinga vegetation, rich in endemic species with peculiar characteristics of adaptation to climatic conditions, playing an important ecological, economic and social role. The vegetation has been altered for a long time by human actions, replacing the vegetation cover for several economic purposes. Therefore, the objective of this study was to carry out a phytosociological survey of the shrubtree vegetation and estimate the woody biomass of a fragment of Caatinga located in the city of São José de Espinharas, Paraíba using an allometric equation and Remote Sensing. To meet the objectives, a forest inventory was carried out, in which 20 plots of 20m x 20m (400 m²) were installed and georeferenced, totaling a sampled area of 0.8 ha, where all individuals with a CAP greater than 6 cm were measured. . In the study area, 1,145 individuals were sampled, whose most representative families were Fabaceae and Euphorbiaceae, a data similar to other studies in similar areas. The species that stood out with the greatest importance were Poincianella pyramidalis, Mimosa tenuiflora, Aspidosperma pyrifolium, Croton blanchetianus and Combretum leprosum. In the quantification of biomass generated by vegetation indices (NDVI, STVI1, STVI2, STVI3 STVI4) and allometric equations, it was found that the indices used showed a high correlation with the data, with the highest values being of the determination coefficient and the lowest residual standard deviation, for the STVI4 and STVI1 indices, the one with the highest determination coefficient value and residual standard deviation being considered the best model, the model generated by the STVI4 with R²= 0.75 and residual standard deviation equal to 4.77 t/ha. The results showed that this index can be used in areas of Caatinga, requiring further studies to collaborate with the results achieved.