The objective of this work was to evaluate the use of Landsat 8/OLI images to differentiate the age and estimate the total volume of Pinus elliottii, in order to determine the applicability of these data in the planning and management of forest activity. Fifty-three sampling units were installed, and dendrometric variables of 9-and-10-year-old P. elliottii commercial stands were measured. The digital numbers of the image were converted into surface reflectance and, subsequently, vegetation indices were determined. Red and near-infrared reflectance values were used to differentiate the ages of the stands. Regression analysis of the spectral variables was used to estimate the total volume. Increase in age caused an addition in reflectance in the near-infrared band and a decrease in the red band. The general equation for estimating the total volume for P.elliottii had an R2adj of 0.67 with a Syx of 31.46 m3 ha-1. Therefore, the spectral data with medium spatial resolution from the Landsat 8/OLI satellite can be used to distinguish the growth stages of the stands and can, thus, be used in the planning and proper management of forest activity on a spatial and temporal scale.

The uncontrolled expansion of human activities may lead to a reduction in vegetation cover, an increase in erosion processes and soil sealing. The aim of this study is to examine forest cover using the Weights of evidence method based on land use maps between the years of 1996 and 2011 in the micro-region of the Campanha Ocidental located in the state of Rio Grande do Sul (Brazil). The spatial database was constructed in SPRING software (version 5.2.1) based on LANDSAT 5 images, which were georeferenced and classified. Geophysical and socioeconomic variables were included in the database for further analysis in Dinamica EGO software (version 2.2.8). In order to parameterize the probabilistic model for the analysis of the dynamics of forest cover change, we calculated the percentage of class change through transition matrices; calculated the intervals for discretization of continuous variables; calculated the weights of evidence (W+); analyzed the correlation between the weights of the input variables for all transitions; simulated future scenarios and; validated the simulated final map based on the historical map. This model was adequate for understanding the variables that most contribute to forest cover change in the region. The results showed that the emergence of new forest areas was influenced by hypsometry, distance to sandy lands and per capita income, while deforestation by rural population and distance to the sandy lands.

The application of spectroradiometry techniques to the study of tree species allows the acquisition of information related to plant physiology and morphology, which can be used in conjunction with orbital images. However, it is known that when a leaf is extracted the senescence process is started, which is characterized by cell constituents degradation, loss of water and modifications of the foliar mesophyll structure. In this context, this study aimed to evaluate the influence of the collection time and storage form on the spectral response of ipê-amarelo leaves. Thus, 32 leaves were collected in distinct times (1h, 2h, 24h and 48h) and conditioned with(C) and without(S) thermal storage. The data were evaluated from the visual analysis of the spectral curves, derivative analysis and statistical analysis. The experiment was conducted in a Randomized block design and data were submitted to analysis of variance (ANOVA) and Tukey test (p = 0.05). Results indicated that thermal storage might delay the senescence process of the leaves. Both the collection time and the storage form affect the pattern of spectral behavior of the leaves of ipê-amarelo. The collection time has not shown significant differences between 1-2h. The largest differences were found between 2-24h after collection.

Os avanços tecnológicos e científicos da fotogrametria digital e o elevado número de dados extraídos por meio desta área de conhecimento, têm impulsionado o desenvolvimento de equipamentos e softwares de processamento. Justificando-se a necessidade da inclusão de plataformas educacionais para o ensino da fotogrametria digital no ensino técnico, atuando como facilitador do ensino e dando acesso à equipamentos e softwares, muitas vezes restritos pelos seus altos custos. Este artigo teve como objetivo avaliar a usabilidade da Plataforma Fotogramétrica Educacional E-Foto para o ensino da fotogrametria digital no ensino técnico. Os dados foram obtidos a partir da aplicação de um questionário online em uma turma de 14 alunos do curso Técnico em Geoprocessamento, a partir do qual realizou-se uma análise qualitativa e quantitativa. Para a análise quantitativa utilizou-se o método SUS - System Usability Scale, que possibilitou avaliar, através de uma métrica, que a Plataforma Fotogramétrica Educacional E-Foto atende as exigências de usabilidade de um software com este propósito. Além disso, verificou-se que o E-Foto atinge aos objetivos propostos de ensino, possui tutoriais de apoio que auxiliam a este propósito e que, desta forma, pode ser utilizado, como recurso metodológico adicional no ensino da disciplina de Fotogrametria Digital. Sobretudo, a análise qualitativa permitiu identificar oportunidades de melhorias do sistema, as quais contribuirão para sua melhor usabilidade.