Behavior of Sterculia pruriens (Aubl.) Schum. Sterculiaceae (axixá), in a managed tropical forest, Moju - PA

Abstract

This study aims to evaluate the diameter growth of the Sterculia pruriens (Aublet) Schumann - Sterculiaceae (axixá) population, after selective logging. The study was carried out in the Embrapa Amazônia Oriental Experimental Station in the Moju municipality, State of Pará - Brazil, situated between the coordinates 02° 07' 30" and 2° 12' 06" of South Latitude and 48° 46' 57" and 48° 48' 30" of West Longitude. In each of nine selected gaps, 10m × 50m strips were installed, starting from the gap boarder into the forest interior, in North, South, East and West directions. Each strip was divided into 10m square plots, numbered from 1 to 5, constituting sampling level II. We analyzed the species diameter distribution with an amplitude of more or equal to 5cm dbh, up to the maximum value of 66,8cm which was that measured in the beginning of the monitoring. In the study area, we found high density of Sterculia pruriens individuals immediately and three years after the forest exploitation. In the end of the study, we observed a 9.8% increase in density for individuals above 5cm dbh. The diameter growth for the species in three years of monitoring was 0.27cm. Although low, it is increasing, because of the canopy opening. The diameter distribution analysis shows that the opening was beneficial for the diameter increment of the species, increasing the number of individuals in five of the eight diameter classes analyzed; however, it remains a decreasing distribution.