Florística, fitossociologia e corte seletivo pelo método BDq em uma área de caatinga, Município de São José de Espinharas - PB

Abstract

In the semiarid region of northeastern Brazil , the exploitation of timber forest products in the Caatinga has been wrongly held by those who live there , which is used primarily geared to the extraction of firewood , charcoal production , stakes , posts and forage. To try to minimize these damages caused to this vegetation, the practice of sustainable forest management should be used. This study aimed to develop activities related to the analysis of the floristic composition and phytosociological method using selective cutting BDq in an area with caatiga vegetation. This study was conducted in Laranjeiras Farm, São José de Espinharas - Paraíba. We conducted a forest inventory using systematic sampling, in which 40 sampling units of fixed area of 400 m2 were measured. In these units, we measured all live and still standing dead individuals by measuring the circumference at the base , 0.30 m above the ground ( CNB0 30 ) and total height, having a s minimum level of inclusion individuals that presented C A P > 6 cm and height £ 1.30 m. We simulated three alternative management method based on BDq : reduction of 40 %, 50% and 60% of the basal area. 1,746 individuals belonging to 10 families, 20 genera and 20 species were sampled. The most representative families in number of species were Fabaceae-mimosoideae , Fabaceae-caesalpinioideae and Euphorbiaceae. T h e high mortality of trees in the area was due to the long period of drought that affected the Northeast during the data collection. The basal area was found to be 9,977 m2 ha"1, the mean estimated volume was 29.29 m3.ha~1 ; the pre - established values of the remaining basal area, maximum diameter and constant "q", simulated cutting of trees in all diameter classes in all treatments, except those who had a deficit in the number of trees with greater intensity in the smaller diameter classes. An economic evaluation is required to recommend the use of the method for BDq caatinga biome.