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Volumetric yield analysis is critical to optimizing performance in the timber industry. In the Amazon and in the Amapá state, this information is still little known and scarce, and therefore this study was developed to obtain and analyze the volumetric yield coefficient of ten commercial tree species and to test the variation by diameter class. We collect data of volumetric yield from for ten commercial species. For each species, the yields in different diameter classes were analyzed, as well as the yield difference between the species. The overall yield obtained for the sawmills (43.95%) and the yield of each species are within the established standards for operations in the industry according to the legal requirements. There were no differences (p ≥ 0.05) in diameter classes for species with the exception of Dinizia excelsa and Handroanthus albus. However, there was no linear increase (p ≥ 0.05) between the diameter and yield of lumber for all species. The species Dinizia excelsa, Hymenolobium petraeum, Ocotea rubra and Vochysia guianensis show a significant difference in yield for the other species due to the higher obtained values, however, they are statistically similar when compared to each other.

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Areas of cerrado (Brazilian savanna) in the Amazon have been poorly studied from the perspective of fire impacts on environmental sustainability, especially with regard to disturbances to soil and vegetation structure. This study aimed to analyze the influence of edaphic variables and fire together on the composition and structure of tree and shrub vegetation of three cerrado remnants in the Amazon. Eight plots were systematically installed in burned and unburned environments in each remnant. Data were submitted to floristic diversity, similarity, and diametric and altimetric structural assessments. Phytosociological parameters were obtained and submitted to Principal Component Analysis (PCA) and Canonical Correspondence Analysis (CCA). A total of 808 individuals (34 species, 30 genera, and 21 families) were recorded. The CCA indicated that the distribution of species is influenced by edaphic factors, as confirmed by the strong direct correlation of tree and shrub species with the reduced nutrition and high acidity of the soils common in the analyzed remnants. Our results support the hypothesis that fire plays a relevant role in structuring vegetation since it contributed to good indicators of soil properties and caused changes in the composition of woody species.