Método Bitterlich como ferramenta alternativa para estimar volume de madeira em áreas de Caatinga, sob manejo florestal sustentável

Abstract

The Caatinga biome has undergone significant degradation, generally caused by deforestation, due to the occupation of areas with agricultural activities, livestock farming and use of natural resources. One approach to avoid deforestation and ensure the maintenance of forest cover is to adopt sustainable forest management of this biome. One of the essential subsidies for developing a Sustainable Forest Management Plan is the forest inventory. Among the different inventory techniques, the most widely used is the fixed plot method. However, there are other inventory methodologies that are less costly, such as the Bitterlich method, but it has been little used in the biome to date. The objective of this study was to estimate the volumetric production of wood using the Bitterlich method to evaluate its efficiency in Caatinga areas. The study was carried out in the plots explored on the Quimporó and Estrela do Norte Farms, located in the municipality of Cruzeta, RN, in an area with a Sustainable Forest Management Plan. Two sampling methodologies were used: fixed plots and the Bitterlich method. The first considered 65 sampling units located in 7 plots on both farms. In the Bitterlich method, parallel transects were established with sampling points every 50 meters, totaling 74 points. A Bitterlich bar with a 1 cm opening and 50 cm length was used. The data were tabulated using Excel 2016 and Sisvar software. No differences were observed in the estimates of tree diversity between the two inventory methods. The fixed plot method estimated the average volume per hectare significantly higher than the Bitterlich method. Apparently, the latter underestimates the basal area and volume in areas of caatinga in the regeneration phase, although it presents good accuracy. Future research should test different length and opening parameters that may result in better estimates in this type of vegetation.