Search

Considering the economic importance of the Pinus species in Brazil, especially in the southern region, this study was carried out to fill some gaps and assist in the production processes of this species. The specific objective was to evaluate the influence of different growing space regimes in experimental plantations of Pinus taeda L., aged 35 years, without thinning, located in the state of Santa Catarina. Diameter at breast height (DBH) and total height data were collected, and the Gamma and Weibull (3P) probability density functions (PDF) were used to describe the structure of the diameter and height variables, respectively. Then multivariate analysis and discriminant functions were applied to identify the correlation of these variables. For qualitative variables, tree health was assessed in three classifications: 1 - Healthy, with no apparent damage; 2 - Initial stage of deterioration by pests and/or diseases; and 3 - Advanced stage of deterioration by pests and/or diseases. The trunk quality variable was also evaluated in three classifications: 1 - Trunk without apparent defects; 2 - Slightly crooked trunk, however cylindrical and devoid of considerable ramifications; and 3 - Trunk with strong tortuosity or bifurcation. The results showed that growing space directly affected the average diameter. Stands with greater space per tree maximized the variables when considering height and DBH together. Stands with less growing space, on the other hand, favored better trunk quality, and the dominant individuals in height had superior health and trunk quality compared to the others.

The Weibull function, a continuous probability distribution, is widely used for diameter distribution modelling, in which parameter estimation performance is affected by stand attributes and fitting methods. The Weibull cumulative distribution function is nonlinear, and classical fitting methods may provide a not optimal solution. Invoking the use of artificial intelligence by metaheuristics is reasonable for this optimisation task. Therefore, aimed and compared (1) the metaheuristics genetic algorithm and simulated annealing performance over the moment and percentile methods; (2) the hybrid strategy merging the metaheuristics tested and the percentile method and, (3) the metaheuristics fitness functions under basal area and density errors. A long-term experiment in a Pinus taeda stand subjected to crown thinning was used. According to our findings, all methods have a similar performance, independent of the thinning regimes and age. The pattern of the estimated parameters tends to be acceptable, as b increases over time and c increases after thinning. Overall, our findings suggest that methods based on metaheuristics have a higher precision than classical methods for estimating Weibull parameters. According to the classification test, the methods that involved simulated annealing stood out. The hybrid method involving this metaheuristic also stood out, with accurate estimates. Classical methods showed the poorest performance, and we therefore suggest the use of simulated annealing due to its faster processing time and high-quality solution.

Análises econômicas de projetos florestais são tradicionalmente baseadas em indicadores financeiros – obtidos a partir da construção de fluxos de caixa descontados. Nesse contexto, merece destaque a ‘teoria da renda do Solo – trS’, também chamada de valor esperado da terra – VET. Em contraposição a esta, surgiu a ‘teoria da renda da Floresta – trF’. Foi objetivo do presente estudo apresentar a trF como complemento à trS no contexto de plantações de Pinus taeda no sul do Brasil. A abordagem apresentada pela trF permite avaliar a gestão do ativo florestal por uma outra perspectiva, dando maior ênfase à capacidade do ativo em gerar riqueza de forma sustentável. Conclui-se que a trF é uma abordagem interessante e complementar à trS. De acordo com a trF, plantios de Pinus taeda regulados ou próximos à regulação, com o objetivo de maximizar o retorno econômico de forma sustentada, devem considerar ciclos de produção >30 anos. O manejo multiprodutos apresenta resultado econômico duas vezes superior ao pulpwood, independentemente da duração do ciclo de produção (16-30 anos). O emprego da trF de forma complementar às análises tradicionais, com fluxos de caixa descontados, reforçam a viabilidade de estratégias de manejo multiprodutos com ciclos de produção mais longos que os comumente utilizados.

Purpose: The role of soil biotic and abiotic factors in crucial ecosystem services such as primary production, organic matter dynamics, nutrient cycling, and soil biota community structure in the Araucaria ecosystem remains poorly quantified. We aimed to understand how the site quality affects the development of organic horizons, root growth, soil chemical properties, and the entire soil biota community in even aged and monospecific Araucaria angustifolia plantations. Methods: We collected soil monoliths to describe layers of organic matter and the complex soil food web into these layers. We determined soil pH, soil moisture, total nitrogen, available P, and total organic carbon into each layer (litter, F-layer, H-layer, and A horizon), the biomass of fine roots, the community structure of soil biota, arbuscular mycorrhizal fungi, and nematodes, as well as the microbial biomass carbon. Results: In the high-quality site, there was significantly higher organic matter formation, nutrient cycling (N and P), root growth, soil moisture, soil biota diversity, arbuscular mycorrhizal fungi, nematodes, and microbial activity evaluated by the microbial biomass carbon compared to the low-quality site. Conclusions: High-quality sites promote the development of organic horizons, root growth on superficial layers that provide plant nutrient release, the A horizon nutrient contents, and the entire soil biota community in monospecific Araucaria angustifolia plantations located on humid subtropical Cambisols. This creates a positive plant-soil feedback that maintains soil quality and increases primary production, nutrient cycling, and habitat and food for the soil food web.

Purpose The role of soil biotic and abiotic factors in crucial ecosystem services such as primary production, organic matter dynamics, nutrient cycling, and soil biota community structure in the Araucaria ecosystem remains poorly quantified. We aimed to quantify the role of site quality on the development of organic horizons, root growth, soil chemical properties, and the entire soil biota community in even-aged and monospecific Araucaria angustifolia plantations. Methods We collected and dissected soil monoliths to describe layers of organic matter and the complex soil food web into these layers. We determined soil pH, soil moisture, total nitrogen, available P, and total organic carbon into each layer (litter, F-layer, H-layer, and A horizon), the biomass of fine roots, the community structure of soil biota, arbuscular mycorrhizal fungi, and nematodes, as well as the microbial biomass carbon. Results In the high-productivity site, there was significantly higher organic matter formation, nutrient cycling (N and P), root growth, soil moisture, soil biota diversity, arbuscular mycorrhizal fungi, nematodes, and microbial activity evaluated by the microbial biomass carbon compared to the low-productivity site. Conclusions High-productivity sites promote the development of organic horizons, root growth on superficial layers that provide plant nutrient release, the A horizon nutrient contents, and the entire soil biota community in monospecific Araucaria angustifolia plantations located on humid subtropical Cambisols. This creates a positive plant-soil feedback that maintains soil quality and increases primary production, nutrient cycling, and habitat and food for the soil food web.

Pine plantations are an important wood source in Brazil, with Pinus taeda being most frequently planted. Most pinewood is directed to the paper and pulp industry, but there is an increasing demand for wood for solid end-uses, requiring large stems from longer rotations which can be obtained using P. taeda as the canopy in two-aged stands. We evaluated radial growth and wood density at different stem heights of P. taeda in the highlands of Southern Brazil over a production period of 36 years and subjected to shelterwood harvest. Cross-sectional disks were obtained from 15 trees in different stem heights; 10 were used for growth analyses and 5 for growth and density analyses. We used disk images and X-ray techniques for growth and density analyses, respectively. Samples were analyzed for ring (width and density), earlywood, and latewood (width, density, and proportion). Ring width varied between 0.4 and 1.7 cm, with the widest rings in the first years (3–5 years.) of growth. Ring density increased with age, with higher densities on the lower stem portions. Mature wood started to be formed from the 16th ring onwards. Shelterwood harvest affected both ring width and density, but the effects on ring width lasted for at least 5 years, while the effects on wood density were short-lasting. Mature P. taeda trees increased their size after the shelterwood harvest without compromising their wood density. Longer production periods of P. taeda as retained trees in the canopy of two-aged stands provide high-quality wood for structural purposes.

Background: We analyzed if C. lusitanica can be planted in a shelterwood system with P. taeda as the shelter stratum. The study was conducted in a 13-yr-old C. lusitanica stand under P. taeda canopy in Southern Brazil. Samples of these trees were measured in terms of diameter at breast height (DBH), total height, individual volume, and crown projection area. The species´ growing space efficiency (GSE) was also analyzed. A 10-meters distance criterion from P. taeda trees was applied to check their influence on C. lusitanica growth behavior through correlation. Results: The 36-yr-old P. taeda trees showed expressive means in the dendrometric variables, compatible with its age (mean DBH of 58 cm, total height 30 m, individual volume of 3.7 m³, and crown projection area of 128 m²). There was a statistically significant effect (p>0.05) of P. taeda cover on C. lusitanica diameter (mean of ~13 cm). Although not significant, an effect of P. taeda canopy was also observed on C. lusitanica height. The two species summed a basal area of 36.5 m² ha-1 and a crown projection area of 34,209.2 m² ha-1. A tendency of increasing GSE with increasing diameter was observed for both species. Conclusion: These results show that a shelterwood with C. lusitanica under P. taeda is possible, but further investigations with longer production cycles and with silvicultural treatments (i.e. thinnings and shelter removal) should be conducted for a better understanding of shelterwood systems with these species in southern Brazil in terms of growth performance and soil use sustainability.

Although A. angustifolia is currently economically unimportant, the worldwide trend of conservation through the sustainable use of natural resources together with an intense discussion of governmental regulations and the recent results of genetic breeding started in the 1970s are delivering promising perspectives for a new wave of plantations. This study aimed to determine optimal pruning strategies by evaluating the diameter and height growth of young A. angustifolia trees as affected by different pruning intensities. Pruning quality in terms of occlusion and defect-core size were also investigated. At the age of 6 years, the pruning experiment was started by conducting six different pruning intensities, named after the number of whorls left after pruning (0, 2, 4, 6, and 8), as well as unpruned (U) trees as a control. From the results obtained in the present study, it was concluded that pruning intensity had a significant negative effect on the growth of young A. angustifolia trees. Diameter was more affected than height growth. Pruning young A. angustifolia trees for knotty-free timber production must be conducted keeping 8 whorls after the intervention if no negative effect in current annual increment in diameter is to be observed when compared to unpruned trees. A defect core of 15 cm seems to be a feasible target for the species regarding optimal pruning intensity to avoid losses in diameter growth. This is strongly dependent on a fast occlusion process, which, in turn, is a result of a careful pruning technique.

Loblolly pine is widely planted in southern Brazil. Despite its major relevance for the forestry sector, knowledge about its radial growth at different height levels is scarce—it is unprecedented for trees subjected to crown thinning. The following questions were answered: (1) how many competitors should be removed to favour the radial growth of potential crop trees? and (2) how long does it take to detect enhanced growth rates along the stem and how long do the effects last? The research design included four thinning treatments where competitor trees were removed in different intensities starting at age 5 years. At age 30 years, 20 trees from each thinning treatment were selected, of which cross-sectional discs were taken at 1.3 m, 25, 50 and 75% of commercial height. The removal of one competitor tree per potential crop tree is not sufficient to increase radial growth immediately after thinning—two competitors need to be removed. Growth responses were detected immediately at the tree base (1.3 m), but took ~ 3 and ~ 8 years to be detectable at 25% (~ 8 m) and 50% (~ 15 m) of commercial height. Positive influences on growth rate following thinning take longer to be detectable upwards in the stem than at the trees base. However, once present, enhanced growth rates last longer at higher levels than at the tree base.

Plantation forestry in southern Brazil demands additional timber species to a higher market differentiation by providing high quality timber and exploitation of market niches. Cupressus lusitanica has long been recognized for this purpose but, until now, it was not properly region-wide quantified in terms of growth and yield. The present study delivers the lacking quantitative approach, which may encourage the commercial use of the species. With this study it was aimed at collecting and processing quantitative data from all known C. lusitanica stands in southern Brazil. Inventories were carried out (60 ha, 6-39 years of age) in order to model the development of dominant height (h100), basal area, volume and dominant diameter (d100). Dominant height was the basis for site quality evaluation, delivering site index curves, which, together with the commercial volume of the stands, allowed yield modelling. A wide amplitude of dominant height growth was detected (10-30 m at 20 years), indicating a great site quality variation. At age of 20 years, commercial volumes of 110 and 620 m³ ha-1 were observed for site indexes of 14 and 26, respectively, equivalent to a maximum of 6-31 m³ ha-1 year-1 at ages between 16-18 years. Results demonstrated in a robust manner that C. lusitanica has a high potential for cultivation in southern Brazil. Thus, offering the opportunity of market differentiation by promoting market niches whose demands timber for special solid end-uses.

Araucaria angustifolia (Bertol.) Kuntze is a native tree species of major importance in southern Brazil. It is a regional symbol due to its iconic shape and stature in the landscape; its wood was once economically important and its seeds are an important source of food for the fauna and are presently used in regional cuisine. Despite its importance and apparent abundance, the species is facing extinction mainly as a result of unregulated exploitation and deforestation. This study catalogued the remaining individuals in order to add to the body of knowledge available on A. angustifolia, a species that has become rare across its historic range. The circumference at breast height (1.30 m), the total height, and the tree volume were measured (3,529 araucarias). We catalogued trees with a large diameter measuring them in loco over three years involving a journey of more than 6,800 km. The volumes of these old trees are very large, ranging from 38.2 m3 to 106.6 m3. The largest A. angustifolia individual is located in the state of Santa Catarina and measures 3.25 m in diameter. The giant araucarias with > 2.00 m in diameter are rare and only 13 individuals could be found in southern Brazil; a priority action at the governmental level is to recognize and preserve these monumental trees and together with a need for a public policy of drawing up specific inventories of large trees.

The objective of this study was to evaluate how the fertilizer composition, type and application method contribute to the initial growth of Pinus taeda applied at planting. Seedlings from an open-pollinated seed orchard of Pinus taeda were planted on a Humic Dystrudepts soil containing 15 treatments of fertilizer application at planting. Basal diameter (immediately above ground – about 5 cm) and total height were measured on all live plants after six, 12 and 42 months. The basal diameter at six and 12 months ranged from 0.49 to 0.63 cm and 1.64 to 2.15 cm, respectively. The height at six and 12 months ranged from 0.49 to 0.64 m and 0.77 to 1.01 m, respectively, indicating that fertilizing improved this characteristics in ~30%. Fertilizer composition, type and application method contributed to the first year of growth of Pinus taeda. Nevertheless, fertilization response disappeared after 42 months.

Approximately 1.6 million hectares of southern Brazil are cultivated with pines, and mainly with the loblolly pine (Pinus taeda L.). More than one third of the stands belong to independent log producers, whose aim is to maximize their economic results. In this study, a thinning experiment was evaluated over a production period of 30 years. The stands evaluated were submitted to three different crown thinning intensities, with an unthinned stand used as a control. The aim of the study was to evaluate economic criteria regarding realistic discount rates and production periods varying between 16-30 years. For the circumstances that were evaluated, 'extreme' and early release from competition of pruned loblolly pine trees lead to the best economic performance (land expectation value = ~36,000 US$ ha-1, i = 3% yr-1). Stands subjected to crown thinnings, independently of intensity, produced three times the economic output of unthinned and unpruned stands. Although the optimal harvest ages, according to the internal rate of return, are between 18-22 years for thinned and unthinned stands, from a long-term perspective (land expectation value) and for the current relationship between log price and size, the optimal economic performance requires that production periods are extended (to 24-26 years) from those currently practised in southern Brazil (15-20 years). RESUMO Aproximadamente 1,6 milhões de hectares são cultivados com Pinus no sul do Brasil, principalmente com Pinus taeda L. Mais de um terço dos povoamentos pertencem a produtores de toras independentes, cujos objetivos são maximizar os resultados econômicos. Neste estudo, um experimento de desbastes foi avaliado durante um período de produção de 30 anos. Os povoamentos avaliados foram submetidos a três diferentes intensidades de desbaste 'por copas', também denominado de 'pelo alto', mantendo uma testemunha não desbastada. Objetivou-se avaliar indicadores econômicos considerando taxas de desconto realistas e períodos de produção entre 16-30 anos. Para as circunstâncias estudadas, a liberação 'extrema' e precoce de competição de árvores podadas de P. taeda alcançou o melhor resultado econômico (valor esperado da terra = ~36.000 US$ ha-1, i = 3% ano-1). Povoamentos submetidos a desbastes por copas, independente da intensidade, produziram resultado econômico três vezes maior do que povoamentos sem desbastes e não podados. Embora a idade ótima de corte raso de acordo com a taxa interna de retorno (TIR) seja 18-22 anos para povoamentos desbastados ou não, a partir de uma perspectiva de longo prazo (valor esperado da terra) e para a atual relação preço-dimensão da tora, resultados ótimos econômicos indicam haver necessidade de prolongar os períodos de produção (24-26 anos) em comparação com a atual prática no sul do Brasil (15-20 anos).

The purpose of this study was to evaluate the natural durability of Cupressus lusitanica , Cryptomeria japonica and Pinus taeda woods subjected to a rotting field trial, through mass loss and deterioration index. The trial was conducted in an open field in the city of Curitibanos, State of Santa Catarina, Brazil, for a 24-month period, with evaluations carried out every 6 months. For developing the study, we used the woods of Cupressus lusitanica (16 years) , Cryptomeria japonica (16 years) and Pinus taeda (juvenile=15 years and mature wood>30 years) species, from which test specimens were made with the dimensions of 2.5 x 5.0 x 50.0 cm in thickness, width and length, respectively, following the standards suggested by IUFRO. After 24 months of exposure to the rotting field the woods of C. japonica and C. lusitanica species showed a deterioration index that reflected an evident but moderate attack of fungi and termites, while the woods of P. taeda (juvenile) and P. taeda (mature) showed deterioration index that reflected an intense rotting and intense attack of termites. Regarding the mass loss the woods of C. japonica and C. lusitanica were classified as highly resistant, while P. taeda (juvenile) was considered resistant and P. taeda (mature) was considered moderately resistant. In general, the woods of C. lusitanica and C. japonica showed greater natural durability when used in contact with the soil.

Species of the genus Eucalyptus managed for sawlogs in fast-growing plantations show high potential for substitution for valuable native hardwoods. To obtain high quality wood, technical pruning is necessary. The objective of the study is to analyse the development of the branches for the first and second pruning lifts and to quantify the biomass of the pruned branches. For the study two stands of Eucalyptus grandis were selected (age 18 and 36 months) for evaluating a pruning lift from 0 to 3 m and 3 to 6 m. The average branch diameter and length were 18 mm and 2.1 m in the younger stand and 21 mm and 2.3 m in the older one. The relation between branch diameter and branch length could be expressed in a linear model (R² = 0.8). In both stands a higher proportion of branches were already dead. The oven-dry biomass of the pruned branches was 2.2 ton.ha-1 in the first pruning lift and 1.2 ton.ha-1 in the second. The results showed that branch development in wide spaced and early thinned eucalypt plantations is in line with the objective of high quality wood production. Pruning should take place before 18 month to avoid dead branches. The oven-dry branch biomass cut in the two pruning lifts shows a low volume making a commercial utilization difficult.

Sequoia is a fast-growing, long-living species, producing durable timber. The aim of this study was to test different methods for the vegetative rescue of Sequoia sempervirens trees over 40 years old, made at different periods of the year, and, later, testing the rooting of individualized cuttings in planned arrays. Twenty-four individual sequoias were rescued, applying girdling and semi-girdling at three different heights (-10, 0, and 30 cm). The first collection was made 90 days after application of the treatments, being repeated at 150, 240, and 360 days. The percentage of budding trees and the number of shoots per array were registered. In all collections, shoots produced cuttings, which were placed for rooting in mini-tunnels. Cutting survival (%), rooting (%), and number of roots were registered, per array, and per collection. The species vegetative rescue proved to be efficient for the production of shoots for stem cuttings, especially with girdling at 30 cm and semi-girdling at -10 cm. However, it is difficult to define the best method, mainly because of the genetic effect among stock plants. The rooting of cuttings, of recovered material, presented good results (average >65%), also with great differences among stock plants. The potential for rooting of cuttings varied according to different planting periods, with high rooting rates in all seasons, especially in summer. Sequoia sempervirens shows the potential for vegetative rescue and cloning by rooting of cuttings, and this may lead to new studies, with a view towards fixing clones. RESUMO Sequoia é uma espécie de rápido crescimento, longeva e de madeira durável. O objetivo do estudo foi testar diferentes métodos de resgate vegetativo em árvores adultas de Sequoia sempervirens, realizados em distintas épocas do ano e posterior enraizamento de estacas individualizadas por planta matriz. Resgataram-se 24 indivíduos de sequoia, aplicando-se anelamento e semianelamento em três diferentes alturas (-10, 0 e 30 cm). A primeira coleta foi efetuada 90 dias após aplicação dos tratamentos, sendo repetida aos 150, 240 e 360 dias. Contabilizou-se a porcentagem de árvores com brotações e o número de brotações por matriz. Em todas as coletas as brotações originaram estacas que foram colocadas para enraizar em estufim. No enraizamento das estacas analisou-se a sobrevivência (%), enraizamento (%) e número de raízes por matriz por coleta. O resgate vegetativo da espécie mostrou-se eficiente na produção de brotações para a estaquia, destacando-se o anelamento a 30 cm e o semianelamento a -10 cm. Entretanto, há dificuldade em definir qual o melhor método, principalmente em função do efeito genético entre matrizes. O enraizamento de estacas do material resgatado apresentou bons resultados (média >65%), também com grande diferença entre as matrizes. Diferentes épocas de estaquia alteraram o potencial de enraizamento, contudo, com altos índices de enraizamento em todas as estações do ano, principalmente no verão. Sequoia sempervirens apresenta potencial de resgate vegetativo e clonagem por estaquia, sendo possível conduzir novos trabalhos com vistas a fixação de clones.

Pinus taeda plantations are an important economic activity in southern Brazil, where edaphoclimatic conditions are optimal. Understanding how meteorological conditions influence tree growth is important in such a favorable environment for reaching high growth rates and for predicting tree growth responses to climate change. The study was designed to evaluate the influence of meteorological variables on 30 years of radial growth of P. taeda trees subjected to different crown thinning intensities in southern Brazil. In total, 9280 measurements of ring width and age were evaluated. Residual chronologies were obtained according to standard dendrochronology techniques. Correlation was calculated between chronologies and meteorological variables, and thus the direction and magnitude of the relationship between meteorology and growth was addressed. Results indicated that, accounting for the whole year, meteorological conditions show no particular influence on the radial growth of Pinus taeda trees in the studied region. The exception was the vapor pressure deficit, with a significant and negative correlation with the radial growth of trees at all thinning intensities. When considering seasons, several consistent correlations were detected. Rainfall during winter, previously or at the end of the growing season, was positively correlated with the radial growth of trees at all thinning intensities. A consistent negative correlation between minimum and maximum temperature during winter and the radial growth of trees shows that P. taeda in southern Brazil, regardless of thinning intensity, benefit from colder winters in general and, particularly, from colder days during winter. Although temperature increases in the highlands of southern Brazil, as a result of global warming, may not render the cultivation of P. taeda unfeasible, they may restrict or shift the region of optimum growth as well as require changes in the genetic material. Results also suggest that high-intensity thinning may increase the influence of temperature on growth pattern of the stands.

Although the historical interest in using the wood of Araucaria angustifolia , it is still little known concerning the factors that affect the growth. A broader understanding in this context might contribute to the development of appropriate management systems, thus increasing the productivity of plantations and, consequently, the interest in commercially using this species. The present study was based on monospecific populations established in different site conditions (Site Indices between 18-24) where individuals (n=654) were submitted to different competition levels. With the aid of multiple regression techniques, the factors that significantly affected the accumulated growth in diameter of the trees after 20 years of intervention were determined. For the set formed by all trees, 77% of the growth variation can be explained by three factors: site, the proportion of tree diameter at breast height ( dbh ) of the object tree for analysis in relation to the average dbh of the population before performing the clearings (C dbh _before ) and dominance status in relation to the neighboring trees (C all ). The significance of the competition level before the clearing shows that late clearings have limited effects on tree growth. It is concluded that individuals are benefited for having a dominant position in relation to the neighboring trees, reaching diameters 50% larger at the end of the production cycle. Clearings that favour selected trees by removing direct competitors seem to be an interesting management strategy for the species. Keywords: Parana-pine; Forest Management; Silviculture; Timber Production.

Embora a madeira de Cedrela fissilis Vell. seja de grande interesse comercial, seu uso e limitado em funcao da escassez de informacoes quanto a silvicultura da especie. O objetivo deste trabalho foi avaliar o crescimento e a correlacao deste com variaveis climaticas em seis municipios na divisa dos estados do Parana e Santa Catarina. Amostras radiais do lenho foram coletadas de 42 individuos. Apos secas e lixadas, os aneis de crescimento foram marcados, mensurados e avaliados. O incremento medio em diâmetro foi de 1,1 cm ano -1 . Considerando um diâmetro de corte de 40 cm, estimam-se rotacoes de 30 a 36 anos para a especie. De 42 individuos amostrados foi possivel codatar 28 series de crescimento, apresentando uma intercorrelacao de 0,551. A correlacao de Pearson entre as variaveis climaticas e o crescimento radial C. fissilis nao apresentou resultados significativos para a maioria das variaveis. Contudo, a umidade relativa do ar em dezembro foi significativa e inversamente proporcional ao crescimento radial.

A busca por maior produtividade, menores ciclos de producao e, consequentemente, maior desempenho economico tem levado empresas e proprietarios rurais do Planalto Sul do Brasil a investir em plantacoes de Eucalyptus em detrimento de Pinus . A determinacao da produtividade e do desempenho economico de povoamentos florestais e fator basico para o planejamento e otimizacao do manejo destes. Nesse contexto, o presente estudo foi realizado com o intuito de avaliar o crescimento e o desempenho economico de plantios de Eucalyptus dunnii em diferentes sitios no Planalto Sul do Brasil. Foram utilizados dados de inventario florestal continuo, totalizando 128 unidades amostrais e 10.903 pares de dados dap x h dom . Foram obtidas tres classes de sitio com alturas dominantes assim distribuidas na idade indice de 10 anos: Classe I: 34 a 39 m; Classe II: 29 a 33,9 m; Classe III: 24 a 28,9 m. Povoamentos com d 200 de 30 cm podem ser obtidos ja aos 9 anos de idade em sitios altamente produtivos. Entretanto, demoram de 3 a 5 anos a mais para serem obtidos em sitios menos produtivos. A taxa interna de retorno (TIR) de sitios altamente produtivos e duas vezes maior que em sitios de menor produtividade. Valor presente liquido (VPL) e valor esperado da terra (VET), no sitio de alta produtividade, sao 14 vezes superiores aos observados nos piores sitios. Conclui-se nao so quee mais rentavel produzir E. dunnii em sitios mais produtivos, mas tambem que o cultivo de E. dunnii pode nao ser viavel em sitios pouco produtivos. Palavras-chave: Manejo Florestal; Eucalipto; Manejo para Multiprodutos. Abstract Growth and economic performance of Eucalyptus dunnii at different sites on the Highlands of Southern Brazil. The search for greater productivities, shorter production cycles and thus higher economic performances have led companies and landowners on the Highlands of Southern Brazil to invest in Eucalyptus plantations rather than Pinus . Determining the productivity and economic performance of forest stands is a key factor for their planning and management. In this context, the present study was carried out aiming to evaluate de growth and economic performance of Eucalyptus dunnii in different sites on the Highlands of Southern Brazil. Data from continuous forest inventory were regarded with a total of128 sample plots and 10.903 dbh x h dom paired values. Three site classes were obtained with dominant heights at index age of 10 years as the following: Class I: 34 to 39 m; Class II: 29 to 33,9 m; Class III: 24 to 28,9 m. Stands of d 200 of 30 cm can be obtained since the age of 9 years-old on sites of high productivity, while it takes from 3 to 5 years on sites of lower productivity. The internal rate of return (IRR) on sites of high productivity is twice as high as the ones verified on sites with lower productivity. Net present values (NPV) and land expectation values (LEV) on sites of high productivity are 14 times higher than the ones observed on the worst sites. It was concluded that it is not only more profitable to grow E. dunnii on sites of high productivity, but also that there might be no viability at all of its cultivation on low productivity sites. Keywords: Forest Management; Eucalypt; Multiproducts Management.

A silvicultura de Cunninghamia lanceolata em sua região de origem é amplamente difundida, em função do bom desenvolvimento e da qualidade da madeira para usos industriais diversificados. No Brasil, a espécie é considerada de grande potencial. O presente estudo teve como objetivo levantar aspectos dendrométricos e silviculturais de um povoamento puro de C. lanceolata, com 21 anos de idade e o ajuste de modelos hipsométricos, de volume individual e de afilamento. Confirmou-se o potencial silvicultural de C. lanceolata para a região de planalto do Sul do Brasil. A espécie apresenta crescimento inicial lento, demorando cerca de quatro anos para o seu pleno estabelecimento. Entretanto, o incremento médio anual em volume é satisfatório (28,1 m³ ha-1 ano-1), mesmo em condições de elevada competição (65,3 m² ha-1). Mediante os testes realizados, os melhores ajustes foram obtidos para as equações de Trorey, Schumacher-Hall e Hradetzky, para estimar a altura total, volume individual e afilamento, respectivamente.

In the construction sector, wood is facing competition with other materials such as concrete, steel or plastics. Therefore, there is a need for more efficiency in the forest–wood chain by improving silvicutural management and wood processing technologies. The objective of the study is to analyse the influence of log diameter and quality to recovery rate, veneer quality and economic benefit. The trees used in the study came from a 30-year-old Pinus taeda L. thinning trial in Southern Brazil. In total, 57 logs (20.7 to 67.0 cm) were peeled following the standard industrial processing methods of the plywood mill. Average recovery rate was 54 % ranging from 35 to 72.6 %, with a linear trend (R 2 = 0.48) of increasing recovery with an increment on the log small-end diameter. Results show that the gap between theoretically possible and real recovery was lower in the logs with bigger diameters, indicating their higher efficiency in industrial processing. Moreover, the economic analysis detected that the current prices for log assortments reflect only the industrial potential of low-quality pruned logs. An optimised pruning strategy would result in higher industrial efficiency, which would allow higher log prices. The results indicate that the recovery rate of bigger logs is higher in terms of volume of peeled veneer. The quality and therefore the value obtained from each log were negatively influenced by inadequate pruning strategies. Management of pines for higher value utilisation requires optimized thinning and pruning strategies in order to meet high growth rates and proportionally bigger dimensions of clear wood.

Eucalytpus dunnii é uma espécie subtropical e tem seu cultivo indicado para regiões onde há ocorrência de geadas. Apesar de ser atualmente utilizada para a produção de papel, carvão e chapas, o uso sólido da madeira para fins mais nobres é conhecido, desde que práticas silviculturais como podas e desbastes sejam consideradas. O presente estudo teve como objetivo analisar o crescimento de indivíduos dominantes de E. dunnii submetidos a diferentes intensidades de poda. Foram testadas quatro diferentes intensidades de poda, mantendo uma copa remanescente de 100, 80, 50 e 20% da altura total de árvores dominantes. Foi utilizado um delineamento inteiramente casualizado com 10 indivíduos por tratamento. Passados 20 meses da realização da poda, a manutenção de até 50% da copa foi suficiente para manter um crescimento em diâmetro considerado normal. Mais importante que a proporção de copa remanescente, é o comprimento absoluto das mesmas. Conclui-se que são necessários, no mínimo, 4 m de copa remanescente para que as árvores mantenham um incremento periódico anual acima de 4 cm (média anual durante o período de 17 a 37 meses). Ao ultrapassar este limite, perdas na ordem de 50% do incremento em diâmetro são esperadas.AbstractOptimum pruning intensity in Eucalytpus dunnii for clear wood producing. Eucalyptus dunnii is a subtropical species, indicated for areas where frosts occur. Besides its current utilization for paper, coal and boards production, the potential for nobler solid-uses are recognized, provided that silvicultural practices such as pruning and thinning are regarded. The objective of this study was to analyze the growth of dominant E. dunnii trees subjected to four different pruning intensities: 100, 80, 50 and 20% of the total tree height of remained canopy. Experimental design was fully randomized, with 10 replications per treatment. After 20 months of pruning, maintaining 50% of canopy was sufficient to allow a normal diameter growth. More important than the proportion, was the absolute length of remained canopy. It was concluded that it is necessary to keep, at least, 4 m of remained canopy in order to maintain a periodic annual increment over 4 cm (average during the 17-37 months period). When this threshold is exceeded, lost in the order of 50% in diameter increment are expected.Keywords: Forest Management; Multiple-uses.

Cryptomeria japonica e originaria da regiao temperada do Japao, onde e amplamente plantada em funcao da alta durabilidade e trabalhabilidade da madeira. O objetivo do presente trabalho foi avaliar o desempenho de procedencias japonesas de C. japonica , implantadas em 1980 na Estacao Experimental da Universidade Federal do Parana, municipio de Rio Negro, Parana. Realizou-se levantamento dendrometrico em setembro de 2011, o qual serviu de base para as analises estatisticas e geneticas. A produtividade observada aos 31 anos variou de 9,3 m³.ha -1 .ano -1 na testemunha (Camanducaia), ate 22,2 m³.ha -1 .ano -1 na procedencia Miyagi. A partir dos resultados, foram propostas estrategias de melhoramento genetico para a criacao de uma Area de Producao de Sementes (APS) e um Pomar Clonal de Sementes (PCS), bem como a selecao de individuos superiores para reproducao assexuada. Para tal, considerou-se uma intensidade de selecao que mantivesse ao maximo a variabilidade genetica entre procedencias, mas explorasse a variacao dentro de cada procedencia. As sementes produzidas terao um ganho no crescimento diametrico estimado em 9,2% para a APS (curto prazo) e de 14% para o PCS (medio prazo). Abstract A proposal for the existing germplasm of Cryptomeria japonica (L.F.) Don. at the Experimental Station of Rio Negro, PR, aiming at the production of genetic improved seeds. Cryptomeria japonica is indigenous to the temperate region of Japan where it is widely planted, due to its wood quality, high durability and workability. The aim of this study was to evaluate the performance of Japanese provenances of C. japonica , established in 1980 at Experimental Station of Parana Federal University, municipality of Rio Negro, Parana State. Dendrometric measurements were carried out in September 2011, which was the basis for statistical and genetic analysis. The productivity at age 31 years ranged from 9.3 m³.ha -1 .year -1 (control), up to 22.2 m³.ha -1 .year -1 (Miyagi). A breeding strategy was proposed based on a seed production area (SPA) and on a clonal seed orchard (CSO). Moreover superior individuals for vegetative reproduction were also selected. The selection intensity was suggested considering the maintenance of expressive genetic variability among provenances, but exploring the variation within each provenance. The estimated genetic gain for diameter growth was 9.2% for the SPA (short term) and 14% for the CSO (medium term). Keywords : Forest breeding; seed production area; clonal seed orchard.