Diameter distribution of Vouacapoua americana Aublet in the Brazilian Amazon.

Vouacapoua americana Aublet was classified as endangered in 2013 and its extraction banned in 2014. Forest management allows conservation and sustainable production, but, for this, knowledge of diameter distribution is fundamental. This study aimed to characterize and analyze diameter distribution patterns of the species at different sites in the Brazilian Amazon. Data on trees with diameter ≥ 10 cm were acquired from continuous forest in permanent sample plots and preharvest forest inventories (PHFIs) of nine forest management areas. Absolute density, diameter distribution, and De Liocourt quotient (q) were calculated. Diameter distributions were fitted by a linearized Meyer type I distribution function, and the similarity between distributions was analyzed by the nonparametric Kruskal-Wallis test (H-test). The species showed high density (6.31 to 25.55 trees/ha). Mensrured diameters ranged from 10.00 to 127.32 cm. A decreasing behavior was observed in all diameter distributions, with few discontinuous distributions and mostly truncated distributions. The De Liocourt quotient (q) did not show constancy or proximity, with values ranging from 0.4 to 23.48. Diameter distributions did not differ by the Kruskal-Wallis test (H = 15.45, p = 0.3479). Diameter distributions fitted by the Meyer model resulted in an inverted ?J?-like curve. The diameter structure showed a high density of individuals, a decreasing distribution from smaller to larger diameter classes, a characteristic inverted ?J? pattern, and unbalanced diameter distributions.