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Average wood density of 38-year-old Cariniana legalis (Mart.) Kuntze, a Brazilian native forest species, was found to increase with faster growth and lower stocking, while decreasing from pith to bark. A complete randomised block design was planted with five blocks. Ten trees were harvested in each of three spacing treatments. We hypothesised that the stand stemwood production would not significantly differ depending on tree spacing. However, tree growth would be higher in the wider spacing and wood density would be higher in the narrower spacing. The diameter growth of trees was higher at 3 m × 2.5 m than at 3 m × 2 m and 3 m × 1.5 m. Nevertheless, this higher individual tree growth at 3 m × 2.5 m did not compensate for the greater tree stock density at 3 m × 1.5 m with stand stemwood production at 38 years of 530 m3 ha−1 and 649 m3 ha−1, respectively. These results suggest that C. legalis, which can produce up to 17 m3 ha−1 y−1 of medium- to high-density timber – about 800 kg m−3 – is a promising native species for forest plantations in Brazil.Keywords: Brazilian native wood, management of tropical timber, X -ray densitometry

When 2 Mha of Amazonian forests are disturbed by selective logging each year, more than 90 Tg of carbon (C) is emitted to the atmosphere. Emissions are then counterbalanced by forest regrowth. With an original modelling approach, calibrated on a network of 133 permanent forest plots (175 ha total) across Amazonia, we link regional differences in climate, soil and initial biomass with survivors’ and recruits’ C fluxes to provide Amazon-wide predictions of post-logging C recovery. We show that net aboveground C recovery over 10 years is higher in the Guiana Shield and in the west (21 ±3 Mg C ha-1) than in the south (12 ±3 Mg C ha-1) where environmental stress is high (low rainfall, high seasonality). We highlight the key role of survivors in the forest regrowth and elaborate a comprehensive map of post-disturbance C recovery potential in Amazonia. DOI: http://dx.doi.org/10.7554/eLife.21394.001, eLife digest The Amazon rainforest in South America is the largest tropical forest in the world. Along with being home to a huge variety of plants and wildlife, rainforests also play an important role in storing an element called carbon, which is a core component of all life on Earth. Certain forms of carbon, such as the gas carbon dioxide, contribute to climate change so researchers want to understand what factors affect how much carbon is stored in rainforests. Trees and other plants absorb carbon dioxide from the atmosphere and then incorporate the carbon into carbohydrates and other biological molecules. The Amazon rainforest alone holds around 30% of the total carbon stored in land-based ecosystems. Humans selectively harvest certain species of tree that produce wood with commercial value from the Amazon rainforest. This “selective logging” results in the loss of stored carbon from the rainforest, but the loss can be compensated for in the medium to long term if the forest is left to regrow. New trees and trees that survived the logging grow to fill the gaps left by the felled trees. However, it is not clear how differences in the forest (for example, forest maturity), environmental factors (such as climate or soil) and the degree of the disturbance caused by the logging affect the ability of the forest ecosystem to recover the lost carbon. Piponiot et al. used computer modeling to analyze data from over a hundred different forest plots across the Amazon rainforest. The models show that the forest’s ability to recover carbon after selective logging greatly differs between regions. For example, the overall amount of carbon recovered in the first ten years is predicted to be higher in a region in the north known as the Guiana Shield than in the south of the Amazonian basin where the climate is less favorable. The findings of Piponiot et al. highlight the key role the trees that survive selective logging play in carbon recovery. The next step would be to couple this model to historical maps of logging to estimate how the areas of the rainforest that are managed by selective logging shape the overall carbon balance of the Amazon rainforest. DOI: http://dx.doi.org/10.7554/eLife.21394.002

In this paper we investigate the influence of extractives, lignin and holocellulose contents on performance index (PI) of seven woods used or tested for violin bows. Woods with higher values of this index (PI = √MOE/ρ, where MOE is modulus of elasticity and ρ is density) have a higher bending stiffness at a given mass, which can be related to bow wood quality. Extractive content was negatively correlated with PI in Caesalpinia echinata, Handroanthus sp. and Astronium lecointei. In C. echinata holocellulose was positively correlated with PI. These results need to be further explored with more samples and by testing additional wood properties. Although the chemical constituents could provide an indication of quality, it is not possible to establish appropriate woods for bows solely by examining their chemical constituents.

International audience; The aim of this study was to establish the relationship between the stiffness of scantlings, approaching structural size materials, and small specimens of 6-year-old Eucalyptus urophylla 9 grandis wood using a resonance technique. The correlation between the elastic modulus (E) of the scantlings in longitudinal vibration and small specimens in flexural vibration was r = 75 when comparing the scantling values with the averaged values of the specimens per scantling. However, when the E of each single specimen was compared with its respective scantling, the coefficient of correlation decreased to r = 0.64 in the longitudinal tests and r = 0.61 in the flexural tests. A roughly linear correlation (r = 0.59) between specific modulus and loss tangent was obtained for the small specimens of Eucalyptus. In short, the resonance technique rapidly provided a large, accurate data set of mechanical wood properties as required for high-throughput phenotyping in recent genetic studies.

Few studies have investigated the influence of environmental conditions on the within-tree variation in Eucalyptus wood traits. The genotype and environment effects and their interactions influence the wood properties. Their evaluations are crucial to estimate the genotype values and to select with efficiency. Thus, the aim of this study was to better understand the effect of ground slope and wind speed on the spatial variation of basic density (ρ), stiffness (MOE) and microfibril angle (MFA) of Eucalyptus wood. Wood discs cut along the trunk were sampled from one-hundred fifty 6-year-old Eucalyptus grandis × E. urophylla hybrids growing in three contrasting growing conditions influenced by ground slope and wind regime. Near infrared (NIR) calibrations previously developed for ρ, MOE and MFA were used to predict in our discs. 2-D plots presenting the spatial variation of predicted wood traits were compared. The higher the ground slope, the greater the magnitude of radial variation in ρ, principally in the medium zone of the trunk. The spatial variation of wood stiffness seems to be sensitive to two environmental conditions. The MFA radial decreases were more pronounced where the wind speed was higher. At the base and top of the trees, however, there was no significant effect of growing conditions on the radial variation of the wood properties considered here.

While attention on logging in the tropics has been increasing, studies on the long-term effects of silviculture on forest dynamics and ecology remain scare and spatially limited. Indeed, most of our knowledge on tropical forests arises from studies carried out in undisturbed tropical forests. This bias is problematic given that logged and disturbed tropical forests are now covering a larger area than the so-called primary forests. A new network of permanent sample plots in logged forests, the Tropical managed Forests Observatory (TmFO), aims to fill this gap by providing unprecedented opportunities to examine long-term data on the resilience of logged tropical forests at regional and global scales. TmFO currently includes 24 experimental sites distributed across three tropical regions, with a total of 490 permanent plots and 921 ha of forest inventories.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:02:16Z No. of bitstreams: 1 S0104-77602012000200003.pdf: 772946 bytes, checksum: 5de29e64fde56b96f9ccf0be955b98b9 (MD5) Made available in DSpace on 2013-08-22T19:02:16Z (GMT). No. of bitstreams: 1 S0104-77602012000200003.pdf: 772946 bytes, checksum: 5de29e64fde56b96f9ccf0be955b98b9 (MD5) Previous issue date: 2012-06-01 Made available in DSpace on 2013-09-30T20:03:04Z (GMT). No. of bitstreams: 2 S0104-77602012000200003.pdf: 772946 bytes, checksum: 5de29e64fde56b96f9ccf0be955b98b9 (MD5) S0104-77602012000200003.pdf.txt: 29161 bytes, checksum: a6323a64bf760402fbcd7c9b3004cfae (MD5) Previous issue date: 2012-06-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:16:09Z No. of bitstreams: 2 S0104-77602012000200003.pdf: 772946 bytes, checksum: 5de29e64fde56b96f9ccf0be955b98b9 (MD5) S0104-77602012000200003.pdf.txt: 29161 bytes, checksum: a6323a64bf760402fbcd7c9b3004cfae (MD5) Made available in DSpace on 2014-05-20T15:16:10Z (GMT). No. of bitstreams: 2 S0104-77602012000200003.pdf: 772946 bytes, checksum: 5de29e64fde56b96f9ccf0be955b98b9 (MD5) S0104-77602012000200003.pdf.txt: 29161 bytes, checksum: a6323a64bf760402fbcd7c9b3004cfae (MD5) Previous issue date: 2012-06-01 Objetivou-se, com esta pesquisa, avaliar a qualidade do corte florestal com motosserra, em propriedades rurais no sul do Espírito Santo, considerando aspectos da qualidade e a perda de madeira retida nas cepas. Foram lançadas parcelas de 250 m², onde foram feitas as observações após o corte com motosserra, avaliando-se a qualidade do corte nos seguintes aspectos: presença de espetos; danos por rachadura; cepas com faixa de ruptura fora do padrão; cepas sem o entalhe direcional e a altura da cepa remanescente, com vistas a mensurar a perda de madeira retida nas cepas. de acordo com os resultados, em média, houve presença de espetos em 21,9% das cepas, de rachaduras em 17,2%, de cepas fora do padrão em 44,6% e de cepas sem entalhe direcional em 34,5% das avaliações. Para verificar a influência da realização do entalhe direcional na altura das cepas, o teste-t, a 5% de probabilidade demonstrou que há contribuição para ocorrer maior altura de cepas, nos casos em que o corte foi feito sem o entalhe direcional. A quantidade de madeira retida nas cepas, acima do máximo recomendado, foi, em média, de 2,43 m³/ha, representando um prejuízo de R$ 172,53/ha. Foi verificada que a perda de madeira remanescente nas cepas de eucalipto foi maior nos locais onde, para a derrubada das árvores, não houve a realização do entalhe direcional. Os itens avaliados demonstraram qualidade irregular, indicando a necessidade de melhoria no corte com motosserras. This research evaluated the quality of forest harvest using chainsaw, in farms in the south of Espirito Santo state, Brazil, considering aspects of quality and loss of wood left in the strains. A total of 250 m² plots were launched to collect data of forest cut with chainsaw, for evaluating the quality of the cut related mto: presence of skewers; crack damage; strains burst range nonstandard; strains without the notch directional, and the remaining height of the strain, in order to measure the loss of wood held in the strains. The main results were: the spike was present in 21.9% of the strains, the cracks in 17.2% of the strains, non-standard strains in 44.6% of them and unnotched directional strains in 34.5% of the evaluations. To check the influence of the realization of the directional notch on the height of the strains t-test, at 5% probability, has shown that there is an increased contribution to height of the strains, where the cut was made without the directional notch. The amount of wood held in the strains above the recommended maximum was, on average, 2.43 m³.ha-1, representing a loss of R$ 172.53 ha-1. It was verified that the loss of timber remaining in eucalyptus strains was higher in places where, for the logging, there was not done the directional notch. The items evaluated showed uneven quality, indicating the need to improve cutting with chainsaw. Universidade Federal do Espírito Santo (UFES) Centro de Ciências Agrárias Doutorando em Produção Vegetal Departamento de Ciencias Florestais e da Madeira Professor Doutor em Ciências Florestais Engenheiro Florestal Universidade Federal de Uberlândia (UFU) Centro de Ciências Florestais e da Madeira Doutorando em Engenharia Florestal Universidade Federal de Mato Grosso Departamento de Engenharia Florestal Professor Doutorando em Engenharia Florestal Fibria Celulose S.A. Engenheiro Florestal Analista de Operações Florestais Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Agronômicas Departamento de Ciências Florestais Universidade Estadual Paulista Júlio de Mesquita Filho Faculdade de Ciências Agronômicas Departamento de Ciências Florestais

Tese (professor titular) - Universidade Federal do Paraná, Setor de Ciências Agrárias, Departamento de Ciências Florestais, Concurso Público de Provas e Títulos para o provimento de Cargo de Magistério Superior Inclui referências: p. 75-77 Resumo: Para a produção de madeira de qualidade de Pinus taeda, é necessário realizar o corte dos galhos, denominado poda. A poda deve ser feita no momento adequado para que seja possível a produção do maior volume possível de madeira sem nós. Este momento depende do desenvolvimento das árvores jovens. Com o objetivo de avaliar a reação de árvores de P.taeda a diferentes regimes de poda, foram instalados dois experimentos, um no município de Campo Belo do Sul (SC) e outro em Pinhais (PR), em povoamentos jovens de P.taeda. Nestes experimentos foram testadas diferentes alturas de podas, em épocas distintas. A medição do crescimento em altura e diâmetro das árvores mostrou efeito pequeno sobre o crescimento em altura, e muito grande sobre o crescimento em diâmetro. Como consequência, a produção de volume fica bastante afetada pela poda. As características das copas mais importantes a serem observadas nas podas são a manutenção de uma copa verde de no mínimo 2 a 3 m de comprimento, equivalentes a no mínimo 50 % da altura da árvore, com diâmetro do tronco na base da copa verde de no mínimo 5 a 6 cm, e no mínimo 15 a 20 galhos dispostos em 6 verticilos, com uma somatória de área transversal de 3000 mm². A poda é uma operação que tem custo reduzido, variando de R$ 0,02 a R$ 0,15 por segmento podado. Este custo depende principalmente do custo da mão-de-obra e do rendimento da operação em termos de árvores podadas/operário/dia. O custo da poda por hectare depende do número de árvores podadas, com a ressalva de que as árvores não podadas não podem ser concorrentes com as podadas. A poda deve portanto ser realizada em conjunto com um regime de desbastes adequado, visando eliminar as árvores sem qualidade e concorrentes. O custo da poda capitalizado a 6 % ao ano, permite uma relação benefício/custo de até 33,5 aos 19 anos de idade, dependendo do regime de desbastes. Sugere-se um regime de podas para Pinus taeda no Sul do Brasil. Abstract: For production of high quality Pinus taeda lumber it is necessary to prune the trees. Pruning should be done at the right moment, to allow maximum wood production without knots. This moment depend on the growth of the young trees. Two experiments were installed to test reactions of P.taeda to different pruning regimes. One in Campo Belo do Sul (SC) and the other in Pinhais (PR). Main treatments were different pruning heights at different ages. Measurement of height and diameter growth showed little influence of pruning on height growth, but very high on diameter growth. As a consequence, volume production is highly influenced by pruning regimes. During pruning, a 2 to 3 m live crown should be maintained, equivalent to at least 50 % of tree height, with a stem diameter at crown base of at least 5 to 6 cm. Live crown should have not less than 6 branch whorls, with 15 to 20 branches, and a sum of branch cross section area of 3000 mm². Pruning is a low cost operation, costing R$ 0,02 to R$ 0,15 per tree and pruned section. Costs are influenced basically by wages for workers and their productivity in terms of pruned trees per day. Cost per hectare of planted area depends on stand density and thinning regime. Trees not pruned should be removed from the stand, due to their competition with the pruned trees. Pruning costs capitalized at 6 % annual interest allow a benefit/costs ratio of up to 33,5 at age 19 years, depending on the thinning regime. A pruning regime is suggested for Pinus taeda plantations in Southern Brazil.