Juliana Marchesan

Caracterização espectral de plantios florestais com imagens Landsat 8/OLI para planejamento e manejo florestal

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 nearinfrared 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.

Comportamento espectral de espécies utilizadas em arborização urbana

The aim of this research was to characterize and measure the spectral behavior of six tree species grown at the Federal University of Santa Maria/RS. The studied species were Eucalyptus sp., Ficus benjamina , Inga marginata , Schinus terebinthifolius , Psidium cattleyanum and Handroanthus chrysotrichus . Were randomly collected seven healthy leaves for each specie, andanalyzed with FieldSpec3 Spectroradiometer, in the wavelength range from 350 to 2.500 nm. Were calculated 61 vegetation indices based on the mean average reflectances. Was applied a principal component analysis based on array x species matrice. The differences between the spectral behavior of the species were tested with a variance analysis (Tukey) by each spectral band of the Worldview 2 satellite sensor. The statistical analyses were performed with R software. Hierarchical clustering analysis was performed with PC-ORD 6.0 taking into account the Euclidean distance as measure of dissimilarity. To obtain and process spectral data were used ASD ViewSpecPro 4.05 and SAMS 3.2 softwares. The first component comprehended 90.94% of the variance for the dataset. The lowest ratio between the group and the average differences per specie was in the Red band. The Coastal, Blue, Green, Yellow and Red bands obtained similar behaviors, with differences in the species F. benjamina (except Greens band), I. marginata (Green and Yellow), and P. cattleyanum (Green). The Red Edge band presented no distinction between species. Reflectance differences were more visible in the Near Infrared 1 and 2 bands. Optimized Vegetation Index 1 and Simple Ratio 8 were the most effective indices to study the species.

ANÁLISE MULTITEMPORAL DA DINÂMICA DA COBERTURA E USO DA TERRA NO MUNICÍPIO DE CAÇAPAVA DO SUL-RS POR MEIO DE IMAGENS LANDSAT

This study aims to analyze the evolution of the use and land cover and forest dynamics mainly in the city of Cacapava do Sul in the period 1991-2011. Held digital supervised classification using the maximum likelihood algorithm. The thematic classes were chosen: Planted Forest, Native Forest, Field, Bare Soil, Water and Crops of Winter. Analyzing the classes within these years, we can say that there has been significant change in the class Planted Forest which increased by over 50% in 2011 compared to 1991, however, its area does not correspond to 1% of the municipality. The class with the highest expansion was the Bare Soil, for the period 1991-2011 grew 117.40 km² 58% in the period 1991 to 2011. Classes Native Forest and Field, have coverage of 90% and other uses, distributed in the remaining 10% of the municipal area.