Diameter growth of Brosimum guianenses in a tropical forest after logging in Moju-PA

Abstract

This study aimed to evaluate the Brosimum guianenses (Aubl) Huber behavior in relation to different gap sizes from selective logging carried out in the Experimental Station of Embrapa Amazonia Oriental, in the city of Moju-Pará. Nine gaps had been selected from selective logging, classified as small (200-400 m2 ), medium (401-600 m2 ) and large gaps (>600 m2 ). Around each gap 10 × 50 m transects were installed in the magnetic directions North, South, East and West. Each transect was divided in five plots 10m side, numbered from 1 to 5 from the gap border inside forest, where all individuals with DBH ≥ 5 cm had been measured. The individuals of B. guianenses had presented an average diameter growth of 0.18 cm year -1  in twelve years of monitoring, but this did not modify the decreasing and discontinous standard of the diameter distribution of the species. The results had not evidenced a direct relation between gap size and growth during the monitoring. However, the gap size, the cardinal directions and the period of time had significant influence in diameter growth of the species, being the biggest value (0.30 cm ano -1 ) verified in the large gaps and in the directions East and West, during the three first years after logging, but, throughout the study, this superiority only was showed in the East direction, with the growth in the West direction being surpassed by the growth in the South direction. These results allow to characterize B. guianenses as a species with intermediate light demand.