Variações das propriedades de madeiras tropicais estocadas por diferentes períodos em área de mineração de bauxita na Amazônia.

Abstract

Vegetable suppression as a stage of mining activity generates a significant amount of suppressed wood logs for the excavation activity. These feats are commonly stacked in open-air storage yards in the areas of the project and are exposed as more varied weather conditions, which favor the degradation process. In this way, this work aimed to characterize possible changes in the anatomical structure, variations in density and color in wood stocked with different periods in the mining area. Thus, samples were colleted from the logs of Jacaranda copaia, Astronium lecointei, Caryocar villosum and Protium altissimum, placed in storage yards, categorized between 0 to 8 years of storage. From each species, three replicates (logs) were collected per year of stacking, totalizing 54 samples with different diameters. All analyzes were performed using the heartwood portion. Following the methodology traditionally used in studies of wood anatomy, variations in the cellular dimensions of the anatomical structures, were observed, however these changes do not follow a pattern of increase or decrease in relation to the storage time. In the analysis of the basic density of the woods, variations over the sampling time were founded, being directly proportional in Caryocar villosum and Jacaranda copaia. Their solubility, both in hot and cold water, alternated according to the storage time, being directly proportional in Jacaranda copaia. The color of the wood of all species tended to darken with time of exposure in storage yards, with the species Astronium lecointei being the one that showed the greatest variation in color over time.