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The quality of wood is related to its use and the set of chemical, physical, anatomical and mechanical properties that give them technological characteristics. The objective of this work was to analyze the extractives content, lignin content and pH of native forest woods, aiming to predict and/or improve their uses. The contents of cold and hot water soluble extractives, 1% NaOH and ethanol/toluene, lignin content and pH were quantified. From the means test it was verified the statistical differences between the species. It was concluded, therefore, that woods of native species can be indicated for the production of charcoal, for the manufacture of reconstituted wood products and for use in rural buildings. [ABSTRACT FROM AUTHOR]

From two natural bamboo stands dominated by the bamboo species guadua (Guadua angustifolia Kunth) located in sites with different ecological conditions, culms were assessed in order to elucidate possible changes in physical- mechanical properties and lignin content as well. Test pieces were collected from the two sites and were obtained from guadua culms with ages between 1 and 5 years. Among sites the values obtained of physical-mechanical properties and lignin content tend to increase with culms age; however, these changes were not always significantly different (p>0.05). Those culms from the warmer and drier site located at lower altitude showed on average values significantly (p<0.05) higher of the variables assessed. Considering the results obtained, culm maturity is an important factor influencing both physical-mechanical properties and lignin content, however ecological conditions determine larger differences in these variables to be considered for selecting bamboo culms when specific attributes are required by the market. [ABSTRACT FROM AUTHOR]