USO DE IMAGENS LANDSAT-7 ETM+ PARA O MAPEAMENTO DE PLANTAÇÕES DE Eucalyptus NA REGIÃO NORTE DE MINAS GERAIS

O presente trabalho foi realizado em uma área de plantios de Eucalyptus de propriedade da Acesita Energética Ltda. Os plantios estão localizados nos municípios de Turmalina, Minas Novas, Veredinha e Capelinha, em Minas Gerais. O estudo teve como objetivo avaliar a viabilidade técnica da adoção de imagens Landsat-7 ETM+ para o mapeamento dos talhões de eucalipto. Foram empregadas duas metodologias de digitalização, em mesa e em tela. Duzentos e cinqüenta e quatro talhões foram digitalizados e a área de cada talhão foi calculada e comparada com os valores tomados como referência, fornecidos pela empresa. Como principais resultados citam-se: na digitalização em mesa, 43,30% dos talhões apresentaram erros na faixa de 0 a 5% e 64,95% na faixa de 0 a 10%, enquanto que na digitalização em tela os valores encontrados foram, respectivamente, 48,43% e 70,48%; não se aconselha o mapeamento de divisas com essa metodologia, uma vez que elas requerem maior exatidão; levantamentos expeditos ou de reconhecimento podem ser realizados com qualquer uma das metodologias. Use of orbital images for mapping Eucalyptus forest plantations in the north region of Minas Gerais state, Brazil Abstract The present work was carried out in an eucalypt stand area, belonging to the Acesita Energética Ltda. The stands are located in the municipalities of Turmalina, Minas Nova, Veredinha and Capelinha, Minas Gerais State, Brazil. The objective of this study was to evaluate the technical suitability of adoption of Landsat TM-7+ data for mapping Eucalyptus stands. Two digitalization methodologies were used, on digitizing tablet and screen. A total of 254 stands were digitalized and the area of each stand was calculated and compared with values taken as reference, provided by the Acesita Ltda. The main results were: on the tablet digitalization, 43.30% of the stands presented errors in the range of 0 to 5% and 64.95% in the range of 0 to 10%, while on the screen digitalization the values found were, respectively, 48.43% and 70.48%. It is not recommended to map limits with this methodology since they require a greater accuracy; expedite or recognizing surveys can be carried out with either methodology

Determinação da aptidão florestal de uma microbacia por meio de um sistema de informações geográficas

O objetivo deste trabalho foi determinar a aptidão florestal de uso direto da microbacia do ribeirão São Bartolomeu, localizada cm Viçosa, Estado de Minas Gerais. Os dados básicos usados neste estudo foram os mapas de hidrografia, declividade, solos, rede viária, uso e cobertura da terra, booleano das nascentes e booleano dos corpos d'água. Para determinar a aptidão, primeiro definiram-se os critérios com base em revisão de literatura e consulta a especialistas. Em seguida, estes critérios foram transformados em mapas de critérios (restrições e fatores), por meio de um sistema de informações geográficas. Os mapas de restrições utilizados foram os de: áreas a serem recuperadas, áreas de preservação permanente e florestas. Qs mapas de fatores foram padronizados e ponderados poor especialistas da área florestal, gerando-se, via SIG, os mapas padronizados com seus respectivos pesos. Em seguida, utilizando-se o módulo de suporte à decisão do SIG IDRISI, foi aplicada a técnica de avaliação de critérios múltiplos, nomeada de média ponderada ordenada, dando origem ao mapa final de aptidão, com seis classes de aptidão denominadas inapta, muito baixa, baixa, regular, boa e muito boa. Pelos resultados verifica-se que 110,60 ha (2,19%) apresentam aptidão boa, 1.245,00 ha (24,62%) regular, 1,70 ha (0,03%) baixa e 3700,10 ha (73,16%) inapta. Não houve a presença das classes muito boa e muito baixa. Somando-se as classes ótima, boa e regular, obteve-se uma área de 1.355,60 ha, que representa 26,81% da microbacia. Neste sentido, a microbacia do ribeirão São Bartolomeu apresentou potencialidade média para a atividade forestal de uso direto.The objective of this work was to determine forest land aptness of direct use in the São Bartolomeu watershed, located in Viçosa, MG. The basic data used in this study were hydrography, slope, soil, road network, land use/cover, nascent of water boolean and water noolean maps. To determine optness the criteria were first defined based on literature review and specialist consultation. These criteria were changed into criteria maps (restriction and factors) to be used via the Geographical Information System (GIS). The used restriction maps were: areas to be recovered, permanent preservation areas and forest. The factor maps were standardized and weighted by the forest specialists, obtaining the standardized factor maps with its weights via GIS. Using the support decision module from the IDRISI GIS, the technique of multiple criteria evaluation Ordered Weighted Average was applied to generate the final map with the following six aptness classes: inapt, very low, low, regular, good and very good. The results indicated that 110,60 ha (2.19%) ranked good, 1,245.00 ha (24.62%) regular, 1,70 ha (0.03%) low and 3,700.10 ha (73.16%), inapt. Very low and very good aptness classes were not present in the results. The sum of the very good, good and regular classes yielded an area of 1,355.60 ha, which represents 26.81% of the watershed. Thus, the 850 Bartolomeo watershed presented an average potential for direct forest use

Uso de imagens do satélite ALOS para estimativa do volume de madeira em plantações de Eucaliptos

The availability of orbital data has brought new perspectives to both academic and corporative sectors solving demands in forestry science. The main objective of this work was to evaluate the potential of radar data for estimating the timber volume in Eucalyptus spp stands. For this, the correlations between spectral data and timber volume were performed following the use of Multiple Linear regression models as the descriptors of the relationships established. Images were obtained from radar sensors PALSAR (Phased Array type L-band Synthetic Aperture Radar) aboard the ALOS satellite in areas of eucalyptus production located in Vale do Rio Doce - State of Minas Gerais, Brazil, belonging to CENIBRA. Trees between 4 and 8 years old were selected for the study. The results pointed out that the volume from the stands ware correlated with the biomass index BMI (-65%) and total power Pt (-69). The final results pointed out that the volume variable was better explanied by the regression with the combination of Pt and BMI index. The correlation coefficient showed a median value of 0.49. The results achieved in this study support the hypothesis that data coming from PALSAR, sensors can be used to quantify volume variable in eucalyptus plantations.Pages: 8170-817

APPLYING CLASSICAL FOREST REGULATION METHODS TO SMALLHOLDINGS WITH COOPERATIVE CONSTRAINTS

This study aims to assess the cooperative regulation process of forestry producers in comparison to the traditional individual regulation of properties. Twenty (20) forest properties are studied as examples of the development of three forest regulation scenarios: 1) individual regulation, 2) group regulation, and 3) cooperative regulation. The Net Present Value (NPV) of each of the scenarios is optimized according to mathematical programming models and compared to a baseline scenario without forest regulation. According to the proposed cooperative regulation, properties had a proportion factor for annual net revenue distribution calculated from results of the baseline scenario. By comparing the NPV maximization results from scenarios 1 and 3 with the non-regulation scenario, the cost for individual regulation is on average 25%, while being only 11% for cooperative regulation, that is, a 14% reduction in property regulation costs. Additionally, cooperative regulation had the advantage of dividing properties into fewer areas when compared to individual regulation

Tree species community spatial structure in a terra firme Amazon forest, Brazil

All trees with diameter at breast height dbh >= 10.0 cm were stem-mapped in a "terra firme" tropical rainforest in the Brazilian Amazon, at the EMBRAPA Experimental Site, Manaus, Brazil. Specifically, the relationships of tree species with soil properties were determined by using canonical correspondence analyses based on nine soil variables and 68 tree species. From the canonical correspondence analyses, the species were grouped into two groups: one where species occur mainly in sandy sites, presenting low organic matter content; and another one where species occur mainly in dry and clayey sites. Hence, we used Ripley's K function to analyze the distribution of species in 32 plots ranging from 2,500 m(2) to 20,000 m(2) to determine whether each group presents some spatial aggregation as a soil variations result. Significant spatial aggregation for the two groups was found only at over 10,000 m(2) sampling units, particularly for those species found in clayey soils and drier environments, where the sampling units investigated seemed to meet the species requirements. Soil variables, mediated by topographic positions had influenced species spatial aggregation, mainly in an intermediate to large distances varied range (>= 20 m). Based on our findings, we conclude that environmental heterogeneity and 10,000 m(2) minimum sample unit sizes should be considered in forest dynamic studies in order to understand the spatial processes structuring the "terra firme" tropical rainforest in Brazilian Amazon.Fueron mapeados los árboles con diámetro a la altura del pecho ≥ 10,0 cm en un bosque tropical lluvioso “terra firme” de la amazonía brasileña, en el Sitio Experimental de EMBRAPA, Manaus, Brasil. Las relaciones de 68 especies arbóreas con las propiedades del suelo fueron determinadas mediante análisis de correspondencia canónica sobre la base de nueve variables del suelo. En este análisis, las especies fueron agrupadas en dos grupos: uno, donde estas crecen principalmente en arena, con suelos de bajo contenido de materia orgánica, y otro, con especies que se desarrollan principalmente en suelos secos y arcillosos. La función K de Ripley fue utilizada para analizar la distribución de las especies en 32 parcelas de 2.500 hasta 20.000 m2 , con el fin de determinar si cada grupo presenta cierto grado de agregación espacial como resultado de variaciones del suelo. Una agregación espacial significativa para los dos grupos solo se encontró en unidades de muestreo > 10.000 m2 , en particular, para especies en suelos arcillosos y ambientes más secos, en los que las unidades de muestreo parecían cumplir con los requisitos de las especies. Variables del suelo, mediadas por la posición topográfica, influyeron la agregación espacial de especies, principalmente en la gama de distancias intermedia a grande (≥ 20 m). Según los resultados, se concluye que la heterogeneidad ambiental y tamaños de unidades de muestreo de por lo menos 10.000 m2 se deben considerar en los estudios de dinámica de bosques con el fin de entender los procesos espaciales que estructuran la selva tropical “terra firme” en la amazonía brasileña

Inclusion and effect of spatial characteristics on models of forest regulation

The objective of this study was to propose alternative ways of including environmental constraints on models of forest regulation. The propose were minimization of the variations of the distances between the management units with harvest intervention and the unit where production is delivered; maximization of the net present value (NPV), with the application of allowed variation in distance (of 5, 10, 15 and 20 %) between the management units with harvest intervention the unit where production is delivered; maximizing the distance between management units with assistance from harvesting; minimization of the variation of the distance between the management units with harvest interventions; maximization of the net present value (NPV), with the application of allowed variation in distance (of 5, 10, 15 and 20 %) among the management units with harvest intervention. The models were evaluated economically by the net present value (NPV) and environmentally by a harvest area index (IAC). The proposed formulations were environmentally better than the classical formulation (Model I)

Sistema de otto-codificação modificado para endereçamento de redes hidrográficas An improved stream network addressing system: the modified pfafstetter coding scheme

Há, no âmbito do gerenciamento de recursos hídricos, uma carência por sistemas de aplicação global que referenciem, indiquem e identifiquem, de forma única e eficiente, a organização espacial das bacias hidrográficas e respectivas redes de drenagem. Neste trabalho, propôs-se uma modificação no sistema de endereçamento originalmente concebido por Otto Pfafstetter. A nova metodologia utiliza tão-somente as redes de drenagem no formato vetorial e considera, em vez da área das bacias, o comprimento dos seus cursos d'água para codificá-los. Essa estratégia elimina o elevado ônus associado à obtenção de dados de altimetria e à derivação dos respectivos modelos digitais de elevação, imprescindíveis à correta determinação das áreas de contribuição das bacias hidrográficas. Adicionalmente, elimina-se o esforço computacional das operações baseadas em localização espacial, uma vez que agora é possível realizá-las exclusivamente por atributos. Com base nessa metodologia, desenvolveu-se o aplicativo Otto-Sys, utilizando a linguagem de programação AML, nativa do sistema de informações geográficas Arc/INFO workstation. Para exemplificar os resultados da otto-codificação por comprimento dos cursos d'água, apresentou-se um estudo de caso utilizando a rede de drenagem do rio Caeté, afluente do rio Iaco, pertencente à bacia do rio Purus, no Estado do Amazonas. O detalhamento dessa hidrografia vetorial implicou cinco níveis de codificação. Tendo-se codificado toda a rede hidrográfica, qualquer sistema de informações geográficas, mesmo aqueles que não dispõem de recursos específicos para análises e navegação em redes, poderá oferecer serviços de navegação topológica, organização, estruturação, endereçamento e gerenciamento dessas bases de dados. Desse modo, o acesso em tempo real a tais procedimentos poderá ser perfeitamente estendido a qualquer dispositivo capaz de acessar os sistemas web.<br>This paper presents a new numbering system based on the Pfafstetter codification scheme developed for stream networks. Its main advantage is the use of the segments' length instead of the catchments' areas for establishing the Pfafstetter code, therefore eliminating the need for elevation data. This methodology was then implemented in a software named Otto-Sys, developed for Arc/INFO workstation in AML. In order to present the results of this new approach, a case study was carried out for the stream network of the Caeté River, a tributary of Iaco River, belonging to the Amazon River basin. The details of such a digital hydrographic dataset led to 5 level-deep codes. Each codification level is stored as a new column of the attribute table and the corresponding level dictates the number of digits of the code. Once this codification scheme has been established, network-tracing tasks can be performed in any geographic information system using only attribute queries. This strategy speeds up such processes enabling them to be extended to real-time web-based devices

Regulation of even-aged forest with constraint of age classes per compartment

The objective of this study was to present the formulation of alternative models of regulation of the forest, with the inclusion of environmental and social characteristics for the management of the landscape. The models were constructed for a model farm, with an area of active planting of 3491 ha, divided into 135 management units. The regulation models were formulated as type I model, including integrity constraints for the management units. We use meta-heuristic genetic algorithm for solving the models. The alternative proposals were formulated: (i) the formulation of a classical model of regulation, (ii) application of adjacency constraints, and (iii) the restriction of age classes per compartment. The models were evaluated economically by the net present value (NPV) and environmentally by the Crop Area Index (CAI). The application of the technique of genetic algorithm is efficient for solving the constructed models with socio-economic and environmental constraints. The imposition of restrictions adjacency reduced overall NPV by about 8%, and the restriction of age classes per compartment was equal to 5% when this was required in seventh year. The imposition of adjacent and compartment restrictions showed an improvement in environmental quality of the regulatory model demonstrated by the CAI