Silvicultural aspects of Brazil nut (Bertholletia excelsa) in agroforestry systems in Central Amazonia

Abstract

This study evaluated the development of Brasil nut (Bertholletia excelsa) in agroforestry systems established on non-flooding plateaus in Central Amazonia. Three multi-strata agroforestry systems established in 1992 in degraded pastures, located at the Experiment Station of Embrapa Amazonia Ocidental, BR-174 highway, km 54, Manaus, Amazonas, were evaluated. The area had been intensively managed as pasture for six years, then abandoned for four years, and reopened with traditional slash and burn practices to plant the agroforestry systems. Species development was evaluated with measurements of survival rate, trunk diameter at breast height (DBH), total tree height, crown diameter, canopy proportion, degree of slenderness, prominence index, inclusion index and crown shape. At 12 years of age, the trees had a mean total height of 20.9 m and DBH of 37.9 cm, with an annual mean increment of 1.74 m and 3.16 cm, respectively. Mean survival was 78%, with mortality due windstorms and lightening. These observations confirm the suitability of this species to help rehabilitate degraded areas and be included in agroforestry systems.