Crescimento e morfometria de Bertholletia excelsa Bonpl. 20 anos após o plantio: efeito do espaço vital de crescimento

Abstract

Spacing or density of planting (here called vital growth space) is one of the main factors affecting the growth and production of forest plantations. The Brazilian nut tree (Bertholletia excelsa Bonpl.) Is a native species of recognized socioeconomic and ecological value and has been widely used in different planting systems. However, the effects of living space on B. excelsa production plantings were still poorly investigated. In the present study, the objective was to verify the effects of living space (EV) by analyzing information on survival, growth and morphometry of B. excelsa in planting production. For this purpose, an experimental study with six vital growth spaces (12 m2, 16 m2, 20 m2, 25 m2, 30 m2 and 36 m2) was analyzed after 20 years of planting. The main variables analyzed were: survival, breast height diameter (DBH), total height, aerial biomass production, commercial stem volume, crown projection area, length (L) and crown diameter (DC) , foliar area (AF), specific leaf area (AFE) and morphometric indexes, degree of slenderness (GE), crown ratio (PC), coverage index (IA), salinity index ). Survival rates were greater than 70% at all spacings. The variation of the living space influenced the growth in DBH, biomass, volume, canopy characteristics and GE, PC and IA indices, but was not related to growth in height and IS and FC indices. The AFE varied significantly between the different sections of the canopy and decreased with the increase of EV Approximately 80% of the individual aerial biomass was partitioned to the stems in the different vital spaces. The results demonstrate that after 20 years of planting B. excelsa has growth and morphometry patterns differentiated in response to the variation in the living space.