Crescimento de Árvores de Bertholletia Excelsa Bonpl em Plantio Florestal na Amazônia Central

Abstract

Bertholletia excelsa Bonpl is a species with timber potential that is well accepted by the consumer market and performs well in reforestation and recovery of degraded areas. Research that evaluates the growth of the species and how it responds to different temperature and rainfall conditions is considered important for management and silvicultural activities. Stable isotopes are tools that can be used to understand the behavior of plants throughout their lives. Determining trunk growth by means of ring and stable isotope analysis provides information on the environmental conditions available during tree growth and on the factors that influence growth. In order to obtain more information on the growth of the species, the aim of this study was to investigate the growth and effect of variations in temperature and rainfall on trees of Bertholletia excelsa Bonpl in a forest plantation in Central Amazonia. The research was carried out at Fazenda Aruanã, located on the AM 010 highway at km 215, in the municipality of Itacoatiara. The cutting area covers 12.45 ha, where 33,000 seedlings were planted in 1999 at a spacing of 2.5 x 1.5. Thirty trees in five different diametric classes were randomly selected according to the criteria of straight stem and good phytosanitary conditions. 1.30m height discs (DBH) were obtained from all the trees. After marking and measuring the growth rings in 4 radii, the rings were synchronized and standardized using the COFECHA and ARSTRAN programs, respectively. 27 trees were used for diameter and height growth analysis and 15 trees were used to take samples from the growth rings for stable carbon isotope analysis. The results obtained in this study indicate that the growth of Bertholletia excelsa Bonpl trees shows a different growth pattern and that the plantation has not yet reached its maximum production potential, making it necessary to carry out management practices aimed at removing individuals with smaller diameters. In addition, variations in temperature and rainfall alone were unable to determine the increment and isotopic composition of these trees. In general, the species performed well, strengthening its potential for use in reforestation areas. Monitoring from the initial planting period is recommended to help with management practices and decision making.