The objective of this study was to evaluate the accuracy of the Criterion RD 1000® optical dendrometer in a crop-livestock-forest integration system for measuring total volume and sections with bark of eucalyptus trees. Selected trees were felled, having their actual strict volumes obtained. The Smalian method was used for destructive Non-destructive scaling was using carried out using criterion. Bartlett's test for total volume (p-value 0.5125) and diameter along the stem (p-value 0.1891) was found to be homogeneous. There were no statistical differences between the total volumes obtained by the destructive method compared to the non-destructive and the average form factor. The diameters along the bole obtained by the destructive scaling were the same as those obtained by the non-destructive scaling. For the volume by sections of the bole, it was verified that only in the sections closest to the top and considering the volume up to the top, there was difference with the actual volume. However it corresponded to a small proportion of the total volume (9%). Measurements obtained with the Criterion RD 1000® showed no trend, providing efficient measurements for both diameter and volume along the bole.

Objetivou-se verificar a operacionalidade de aplicativos de smartphones comparando-os com hipsômetro tradicional de comprovada eficiência na mensuração de altura total de árvores em fragmento florestal. O Hipsômetro Vertex IV® foi utilizado como medida real da altura total, diante da impossibilidade da obtenção da variável de forma direta. Foram selecionadas aletoriamente 90 árvores, distribuídas igualmente em três classes de altura: 1 (9,0-15,9 m); 2 (16,0-22,9 m); e 3 (> 23,0 m). Para estimar a altura total foram utilizados os aplicativos para smartphones com sistema operacional Android: Two Point Height (T.P.H); Measure Height (M.H); Smart Measure (S.M) e Hypsometer (HR). Todos aplicativos, por resultar em alturas médias estatisticamente iguais a média obtida com o Vertex®, podem ser indicados para a mensuração de árvores nas diferentes classes de altura. A análise residual e estatísticas Viés (V), Média das Diferenças Absolutas (MD), Desvio Padrão das Diferenças (DPD) e Erro Quadrático Médio (RMSE) indicaram que o Hypsometer apresentou menor tendência nas estimativas, distribuição de resíduos mais homogênea, além de resultar em menor erro médio. A atualização dos aplicativos, a resolução do acelerômetro e os cuidados na medida foram determinantes para o desempenho dos aplicativos como alternativa viável para a mensuração de árvores em relação ao custo e eficiência.Palavras-chave: vertex, acelerômetro, custo. OPERATIONALITY OF SMARTPHONE APPLICATIONS FOR MEASURING TREE HEIGHT IN THE CERRADO-AMAZON ECOTONE REGION ABSTRACT: The objective verify the operability of smartphone applications comparing them with traditional hypsometer of proven efficiency in the measurement of total height of trees in forest fragment. The Vertex IV® Hypsometer was used as a real measure of total height, due to the impossibility of obtaining the variable directly. 90 trees were randomly selected, distributed equally in three height classes: 1 (9.0-15.9 m); 2 (16.0-22.9 m); and 3 (> 23.0 m). To estimate total height, the following applications (Apps) were used for smartphones with Android operating system: Two Point Height (T.P.H); Measure Height (M.H); Smart Measure (S.M) and Hypsometer (HR). All tested applications, as they result in average heights statistically equal to the average obtained with the Vertex®, can be indicated for the measurement of trees in the different height classes. The Bias (V), Mean of Absolute Differences (MD), Standard Deviation of Differences (DPD) and Mean Square Error (RMSE) statistics indicated, considering all applications, that the Hypsometer presented a less tendentious and more homogeneous distribution of residues, besides a smaller average error. Upgrading applications, accelerometer resolution, and tailored care were key determinants of application performance as a viable alternative for tree measurement in terms of cost and efficiency.Keywords: vertex, acelerometer, cost.

ResumoO presente trabalho teve como objetivo avaliar o desempenho de diferentes funções de densidade probabilísticas (FDP) na caracterização da estrutura diamétrica de um povoamento híbrido de Eucalytpus urophylla x Eucalyptus grandis de doze anos, no município de Tangará da Serra, Mato Grosso. Foram mensurados os diâmetros à altura do peito dos indivíduos amostrados e agrupados em seis classes, com amplitude de 4,5 cm. Foram calculadas as estatísticas descritivas e verificado o comportamento da variável diâmetro à altura do peito DAP). Para avaliar a distribuição diamétrica dessa espécie foram ajustadas funções densidade de probabilidade: Normal, Log-Normal, Weibull-2P, Gamma e Weibull-3P. A qualidade dos ajustes foi verificada através do teste de aderência de Kolmogorov-Smirnov e Critério de Informação de Akaike (AIC). A função que melhor estimou a distribuição diamétrica foi a Weibull-3P, com menor valor para o teste de aderência de Kolmogorov-Smirnov e menor AIC.

The forest monitoring after exploration activities is an important tool for forest management, helping to plan the use of forest resources. This research aimed to evaluate the impacts on tree vegetation after one year of the end of forest harvesting in concession area in the Jamari National Forest, RO. The vegetation was evaluated before and after the exploitation in an Annual Production Unit (APU) with cutting rate of 14.14 m³ ha-1. In total, seven permanent plots of 0.5 ha were divided and randomly distributed, where all individuals with diameter at breast height (DBH) ≥ 10 cm were evaluated. Impact evaluation was based on two criteria, the diversity and structure of vegetation (phytosociological, parametric, diametric, and internal). There was a reduction of 2% in plant density and loss of two species. The volumetric supply decreased in the classes above 80 cm of DBH and the diametric structure maintained the largest supply of plants in the lower classes. The exploration activities collaborated in 3.57% to increase the mortality rate, besides causing slight and severe damages in 15 ind.ha-1. The quality of the stem was predominantly straight (82.36%). The damage observed is within the expected limits for areas with low cut rates and subjected to reduced impact exploration techniques. We suggest the continuous monitoring in the medium- and long- term in order to describe the patterns of regeneration and growth of species, mainly logging, projecting the future supply of cutting.Keywords: Management in natural forests; Forest dynamics; Forest concession.

Mapping Brazil nut trees in the Amazon is essential for indicating its distribution patterns within different ecosystems, while also being useful to estimate the species productive potential. This study aimed to evaluate the spatial distribution of Brazil nut trees in Flona do Jamari – RO, considering its environmental and topographic conditions. A census was performed for all individual trees sized ≥ 35 cm in diameter at 1.30 m breast height (DBH) above the ground of six Annual Production Units (APU) in Forest Management Unit III (FMU-III), a 11,011.2 ha area of Flona do Jamari, RO. DBH and geographic location (GPS) were collected for each tree. Structure and diameter distribution were evaluated by abundance, density, dominance, and frequency. The Morisita index was used to identify the spatial distribution pattern. The environment was defined by the local relative height found along the drainage network, by the digital model Height Above the Nearest Drainage (HAND). Most trees were among DBH intermediate classes (60 to 140 cm), and only a few were young trees (DBH < 50 cm). Brazil nut trees present a random spatial distribution and a predominant distribution pattern of 'terra-firme (solid ground)'. Such information on the species structural, spatial, and ecological patterns serve as key elements for further studies on production potential.