Critérios para o manejo florestal de Scleronema micranthum Ducke (Malvaceae) em uma floresta de terra firme da Amazônia Central

Abstract

The study of annual growth rings allows the development of models that define the growth pattern of the species, establishing the management criteria as cutting cycle and minimum cutting diameter. The objective of this study was to establish growth models in diameter and volume of Scleronema micranthum Ducke, indicating the criteria of Forest Management for this species, using dendrochronology studies. Ten trees of Scleronema micranthum were selected and one disk of each individual was removed from the base of the log. The discs were dried at room temperature and sanded with sandpaper of different granulometries (36 to 1200 g/cm²), allowing visualization, marking, counting and measurement of growth rings. Growth ring width measurement was performed using image analysis software, Image Pro-Plus. For each sample, four spokes were measured in the spinal-bark direction. To verify the synchronization of the width of the annual growth rings and generate a timeline for each tree, the TSAP-Win software was used. The age of the trees was determined by the direct counting of the growth rings present in the wood of the trees. For the growth modeling study, the GOL (Growth Oriented Logging) management model was used. The species Scleronema micranthum has very distinct annual growth rings, delimited by bands of marginal parenchyma and presence of fibrous zone in latewood. The species presented age ranging from 124 to 155 years and mean increment in diameter of 0.41cm.year-1. The species reached the maximum current increase in volume in the average age of 139 years. The specific minimum cut diameter recommended for Scleronema micranthum is 52.9 cm with a cut cycle of 26.27 years. The results indicate that the management criteria, cutting cycle and minimum cutting diameter, provided by current legislation, do not guarantee the sustainability of the species.