Evaluation of the quality of wood from naturally fallen trees in the central Amazon

The objective of this study was to assess the quality and potential of wood from naturally fallen trees in the forest for product development and to provide subsidies for the use of raw material. The inventory of fallen trees was carried out along the road from the Experimental Station of Tropical Silviculture of the National Institute for Research in the Amazon (EEST / INPA) - Nucleus ZF-2, at km 23 of the ZF-2 road that starts to the left of km 50 of Highway BR-174 (Manaus-Boa Vista).  Only trees that had fall characteristics due to natural factors, that is, that had exposed roots, were considered for the inventory. It was also stipulated as a requirement for measurement the diameter class of trees of 25 cm ≤ DBH ≤ 45 cm. From each naturally fallen tree, the diameters (largest and smallest) and their length were measured. 5cm thick discs were removed from the trees to obtain samples for scientific identification of the wood and determination of physical properties. Based on the inventory, it was identified that many of the trees naturally fallen in the forest are in good conditions of use, considering their woody material and their volume. The Alexa grandiflora species presented the highest volume with 2,788 m³ for a single tree, followed by the species Ormósia sp. with 2,287 m³ and Protium tenuifolium Engl with a volume of 1,269 m³. Regarding the health of the inventoried trees, all from the species Byrsonima crispaJuss. had no sign of degradation, followed by the species Croton lanjouwensis and Ingá sp. The most frequent class was medium density with 9 species with a variation of 0.47g/cm3 to 0.62g /cm3. Eperua schomburgkiana Benth was the most dense with 0.78g /cm3.The levels of degradation found and the intrinsic characteristics of the species did not compromise the possibilities of using this wooden product, and can represent an excellent opportunity for economic return, contributing to minimize the pressures exerted around the living forest