ABSTRACT In Brazil, all transport and storage of native forest products and by-products must be registered within the DOF (Document of Forestry Origin) system. This computerized platform exists to support control agencies in reducing the sale of forest products obtained illegally. However, this tool still shows only modest results in fulfilling its objectives, since gaps in the system allow illegal wood to be acquired and enter the system as legal wood. The objective of this study was to test whether the volumetric yield coefficient (CRV) of a sawmill on an industrial scale corresponds to the 35% established by Brazilian legislation. The focus was directed at a loophole that allows the accumulation of virtual credits in the DOF system by turning logs into lumber. For this purpose, we estimated the sawmill’s CRV and mean percentage yield of 19 commercial species used by a timber company in the Brazilian Amazon with a sample size of 90 logs. The estimated CRV was 24.6 ± 2.4, showing 9.9% uncertainty. The mean CRV differed highly significantly (p < 0.001) from that proposed by the DOF, with a 10.35% difference. Based on these results, the difference between the observed yield and that proposed by the legislation can generate the accumulation of virtual log credits. With this accumulation, managers encounter difficulties in acquiring new logging permits and, consequently, do not meet the actual demand for logs to the sawmill’s capacity.

RESUMO No Brasil, todo transporte e armazenamento de produtos e subprodutos florestais nativos deve ser registrado no sistema DOF (Documento de Origem Florestal). Essa plataforma informatizada existe para apoiar agências de controle na redução da venda de produtos florestais obtidos ilegalmente. No entanto, essa ferramenta ainda apresenta resultados modestos no cumprimento de seus objetivos, uma vez que lacunas no sistema permitem que madeira ilegal adquira caráter legal. O objetivo desse estudo foi testar se o coeficiente de rendimento volumétrico (CRV) de uma serraria em escala empresarial corresponde aos 35% estabelecidos pela legislação brasileira. O foco foi direcionado para uma brecha que permite o acúmulo de créditos virtuais no sistema DOF, por meio da transformação de toras em material serrado. Para tanto, estimamos o CRV da serraria e os rendimentos percentuais médios de 19 espécies comercializadas por uma empresa de base florestal na Amazônia brasileira, com um esforço amostral de 90 toras. O CRV estimado foi de 24,6 ± 2,4, mostrando incerteza de 9,9%. O CRV médio diferiu altamente significativamente (p < 0,001) do proposto pelo DOF, com uma diferença de 10,35%. Com base nesses resultados, a diferença entre o rendimento observado e o proposto pela legislação pode gerar um acúmulo de créditos em toras virtuais. Com esse acúmulo, os gestores enfrentam dificuldades para adquirir novas licenças de exploração e, consequentemente, não atendem à real demanda por toras da capacidade instalada de sua serraria.

Abstract This work aimed to evaluate the monthly growth rate of 100 trees spread in different diametric classes and ecological groups of a secondary forest in the municipality of Igarapé-Açu, Pará, Brazil. These were selected randomly from 30 permanent plots and classified into 5 diametrical classes and separated into two ecological groups: Pioneers and Non-Pioneers. The monthly periodic increment (MPI) in diameter was measured for 11 months by means of diametric bands using digital calipers. The MPI means were evaluated by an analysis of variance (ANOVA) and Tukey’s mean comparison test. Individuals from both ecological groups had similar increments in the DBH IV diameter class and different in the others. There were mean increments in the diametric classes that did not differ within the ecological groups. The trees analyzed differed in the diametric growth rate according to the diametric classes, ecological groups and the month of analysis.

ABSTRACT Buttresses and other natural structures modify the shape of stems in Amazonia and change the diameter at breast height (DBH) measured at 1.3 m at ground level. The lack of adequate measurement techniques affects negatively forest dynamics analyses and biomass estimating. The study evaluated an indirect method of measuring diameters in trees with DBH > 40 cm using principles of digital photogrammetry. The results obtained with two cameras (smartphone and Sony) were compared with direct measurements using diametric tape and a ladder. The technique is adequate to measure the diameters of trees with measurement point above 2 m of ground, with a confidence interval of ±1cm. The use of photogrammetry as a supplementary tool to the diametric tape (IC ± 0.24 cm) is recommended, helping to measure trees with diameter above the reach of the technician in forest inventories.

ABSTRACT The mechanical performance of soil stabilization using lime to improve forest roads was assessed. This study was conducted with lateritic soil (LVAd30) using lime content of 2% in the municipality of Niquelândia, Goiás state, Brazil. Geotechnical tests of soil characterization, compaction, and mechanical strength were performed applying different compaction efforts and curing periods. The results showed that lime content significantly changed the mechanical performance of natural soil, increasing its mechanical strength and load-carrying capacity. Compaction effort and curing time provided different responses in the unconfined compressive strength (UCS) and California Bearing Ratio (CBR) tests. The best UCS value (786.59 kPa) for the soil-lime mixture was achieved with modified compaction effort and curing time of 28 days. In the CBR test, soil-lime mixtures compacted at intermediate and modified efforts and cured for 28 days were considered for application as subbase material of flexible road pavements, being a promising alternative for use in layers of forest roads.

RESUMO O estudo teve como objetivo realizar a caracterização geotécnica e a classificação rodoviária para utilização apropriada de diferentes solos locais como materiais de construção de estradas florestais. O estudo foi realizado em áreas florestais no município de Niquelândia, Goiás, Brasil. Coletaram-se solos finos e granulares predominantes, denominados SL e HA, respectivamente. Os solos foram submetidos a ensaios geotécnicos apropriados para obras rodoviárias, identificando os grupos pertencentes de acordo com as metodologias de classificação TRB e MCT. Os resultados demonstram que o solo SL, com fração predominante de areia fina, possui baixa plasticidade e pertence aos grupos A-4(1) e LA', segundo TRB e MCT, respectivamente. A tensão suportada alcançou 385,10 kPa na maior energia de compactação. A capacidade de suporte foi maior na energia de compactação intermediária. Para o solo granular HA, a fração predominante foi de pedregulho fino e seu enquadramento no grupo TRB foi A-1-b. Segundo a metodologia MCT, o solo SL é material prioritário para base e subleito de estradas. O comportamento esperado para o solo SL é satisfatório como material empregado no subleito, e o HA, excelente, segundo a classificação TRB. A capacidade de suporte dos solos SL e HA indicam que devem ser empregados como reforço de subleito e base, respectivamente. Em estradas florestais, o solo SL pode ser empregado como subleito e HA como base ou revestimento primário.

ABSTRACT The study aimed to carry out geotechnical characterization and road classification for proper use of different local soils, as construction materials for forest roads. The study was performed in plantation forest areas in the municipality of Niquelândia, Goiás, Brazil. Predominant fine and course soils have been collected, which were called as SL and HA, respectively. Soil samples were submitted to appropriate geotechnical tests for road infrastructures, identifying the pertaining groups in accordance with the methodologies of TRB and MCT classifications. The results demonstrate that SL soil has predominant fraction of fine sand and low plasticity, classified as A-4(1) and LA' groups, in according to TRB and MCT classifications, respectively. The supported tension for this soil reached 385.10 kPa on highest energy of compacting. The highest support capacity was reached on intermediate energy of compacting. For HA soil, the predominant fraction was fine gravel and it has fitted into TRB group as A-1-b soil. According to MCT methodology, SL soil is a priority material for base and subgrade of roads. The expected behavior for SL soil was satisfactory as a useful material for subgrade, whereas HA soil was considered as excellent, both in according to TRB classification. The support capacity of SL and HA soils indicates they must be used as reinforcement of subgrade and base, respectively. For forest roads, SL soil is recommended for subgrade and HA for base or primary layer.

RESUMO O objetivo do trabalho foi utilizar as técnicas de geoprocessamento na aquisição, manipulação, espacialização e visualização de dados do padrão de qualidade de estradas florestais, e na confecção de mapas temáticos, com a identificação de pontos críticos para o transporte de madeira, servindo como subsídio para o desenvolvimento de um programa de manutenção preventivo e regular. Identificaram-se e avaliaram-se a integridade e as condições de operação de estradas florestais mediante levantamento contínuo de defeitos na superfície de rolamento e obtenção do ICRNP (índice de condição da rodovia não-pavimentada). A base de dados georreferenciada, a alocação das unidades amostra e a espacialização da rede viária foram obtidas com auxílio da imagem do satélite CBERS II, modelo de elevação do terreno SRTM, e GPS. A identificação e a avaliação das rodovias, por meio de levantamentos detalhados em campo, demonstraram as condições da superfície de rolamento das rodovias, gerando informações sobre os trechos mais críticos e a intensidade de cada defeito, apontando ainda ações e base de custos para manutenção das estradas florestais. As técnicas de geoprocessamento, GPS, sensoriamento remoto e SIG mostraram-se como eficientes ferramentas para a interpretação, qualificação e quantificação de fenômenos naturais da região de estudo e para auxílio na gerência de pavimentos das estradas florestais. O SIG integrou os dados referentes aos padrões de operação e manutenção das rodovias à base de dados georreferenciada, manipulando, espacializando e disponibilizando visualmente, por meio de mapas, as informações geradas.

ABSTRACT This purpose of this research was to apply geoprocessing techniques for data acquisition, preparation, georeference, and display for assessing quality standards of forest roads and mapping critical points of the timber transportation, which contribute to support the development of a pavement preventive and ordinary maintenance program. First, the road pavement integrity and condition were assessed by conducting a continuous survey on road defects and estimating the NPRCI (Non-Paved Road Condition Index). The georeferenced dataset, the sampling unit’s allocation, and the road network spatial location were conducted using satellite (CBERS-II) and SRTM imagery and GPS field data. The road identification and the assessment of pavement condition were based on a detailed field survey, which revealed the road pavement conditions and derived useful supporting information regarding the most critical parts of the forest road and its defect severity, also pointing out practical measures to fix them, estimating costs for the required road maintenance. The Geoprocessing techniques, GPS, remote sensing dataset, and GIS showed to be efficient tools for identifying, mapping, and quantifying this natural phenomenon in the region being studied and may support the definition of maintenance program of non-paved forest roads. Results showed that the GIS could integrate the dataset containing standards of forest road ordinary operation and maintenance to a geographic database, which subsequently allowed to georeference, manipulate, and display this information on thematic maps.