GROWTH AND YIELD OF EVEN-AGED Cupressus lusitanica PLANTATIONS IN SOUTHERN BRAZIL

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

PRUNING Araucaria angustifolia FOR KNOT-FREE TIMBER PRODUCTION

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

GROWTH OF Pinus glabra IN SOUTHERN BRAZIL

Species of the genus Pinus are widely cultivated in Brazil, in the south of the country, mainly P. taeda and P. elliottii are responsible for suppling for diverse industrial segments. Although poorly studied, other species from the same region of natural distribution could also possibly present good growth potential. The aim of the present study was to evaluate the development of different dendrometric characteristics of provenances of P. glabra grown in the highlands of south Brazil during 24 years of growth. The values obtained for P. glabra in the studied region was compared with the ones from its natural distribution region and with data of P. taeda in south Brazil. By means of annual dendrometric measurements during almost the entire studied period, especially at age 24 years, the growth and productivity of the species was addressed. All studied provenances shown suitability to the evaluated edaphoclimatic conditions, with initial height growth above 1 m year-1 during the first 5 years. Productivities above 30 m3 ha-1 year-1 at age 24 years, as well as the production of dominant individuals with 30 cm of dbh at age 15 years can be expected. Therefore, the potential for commercial use of P. glabra in the highlands of south Brazil was proven, thus being an interesting alternative to the commonly used specie

INTENSIDADE ÓTIMA DE PODA EM Eucalyptus dunnii PARA A PRODUÇÃO DE MADEIRA LIVRE DE NÓS

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. 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

EFFECT OF SITE AND COMPETITION ON DIAMETER GROWTH OF Araucaria angustifolia

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 (Cdbh_before) and dominance status in relation to the neighboring trees (Call). 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: Paraná-pine; Forest Management; Silviculture; Timber Production

Determination of thinning optimum age and intensity in a Eucalyptus dunnii stand

Embora o uso tradicional para a madeira do gênero Eucalyptus no Brasil seja a obtenção de papel e energia, diversas espécies desse gênero são consideradas de grande potencial para a produção de painéis, compensados, lâminas e móveis. Para permitir um uso mais nobre da madeira desse gênero, o manejo tradicional precisa ser substituído por rotações maiores, com aplicação de desbastes e podas. O presente estudo teve como objetivo avaliar os efeitos de três diferentes intensidades de desbaste no crescimento em diâmetro, área basal e volume em um povoamento de Eucalyptus dunnii. Os tratamentos foram aplicados mantendo 16, 14 e 12 m² remanescentes por hectare, além da testemunha, realizados em dois diferentes momentos, 3° e 4° ano. A análise do povoamento ocorreu quando ele estava com sete anos de idade, decorridos quatro e três anos da realização do primeiro desbaste. Concluiu-se que o diâmetro médio é maior, quanto menor a área basal remanescente após o desbaste, e que a diferença entre os tratamentos tende a aumentar com o tempo. A redução da área basal para, pelo menos, 14 m²/ha, quando o povoamento possuir 20 m²/ha, é recuperada em termos de estoque volumétrico passados três anos da realização do desbaste.Eucalypts wood has been traditionally used for paper and energy production in Brazil. Recently several species of this genus have been serving other purposes, such as the production of panels, plywood, veneers and furniture. These more value-added wood products require different silvicultural systems, with longer rotation periods and the introduction of pruning and thinning treatments. This study aimed to evaluate the effects of three different thinning intensities on basal area and volume growth of Eucalyptus dunnii stands at two different ages. The thinning treatments were applied either at the third and or the fourth year. The experimental plots had average basal area of 20 m²/ha and 25 m²/ha at the age of 3 and 4, respectively. These forest stands were thinned to 16, 14 and 12 m²/ha of basal area. Volume and basal area growth were analysed at the age of 7 years. The results indicated that the experimental plots undergoing thinning treatments of 14 m²/ha at age 3 were able to equal their growing stock to those of the control treatments after three years

NATURAL DURABILITY OF Cupressus lusitanica, Cryptomeria japonica AND Pinus taeda WOODS IN FIELD TRIAL

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

DENDROECOLOGY OF A 25 YEARS OLD Cryptomeria japonica (L. F.) DON. STAND IN SOUTHERN BRAZIL

Cryptomeria japonica \ue9 origin\ue1ria da regi\ue3o temperada do Jap\ue3o onde \ue9 conhecida como \u2018sugi\u2019. No Brasil, o plantio da esp\ue9cie \ue9 recomendado em regi\uf5es altas e frias do sul do pa\ueds, onde possui boa adapta\ue7\ue3o \ue0s condi\ue7\uf5es edafoclim\ue1ticas. O objetivo do trabalho foi avaliar as correla\ue7\uf5es entre vari\ue1veis meteorol\uf3gicas e o crescimento de um povoamento de Cryptomeria japonica com 25 anos de idade. Para tal, foram coletados discos transversais de 30 diferentes \ue1rvores, compreendendo toda a amplitude de varia\ue7\ue3o diam\ue9trica. Ap\uf3s secos e lixados, os discos tiveram seus an\ue9is anuais de crescimento medidos e correlacionados com dados meteorol\uf3gicos, utilizando ferramentas de an\ue1lise dendrocronol\uf3gica. As s\ue9ries de crescimento apresentaram uma intercorrela\ue7\ue3o de 0,668. O crescimento radial da esp\ue9cie foi influenciado positivamente pela temperatura m\uednima do m\ueas de setembro e pela temperatura m\ue9dia do m\ueas de maio. N\ue3o houve correla\ue7\ue3o significativa do crescimento com a precipita\ue7\ue3o, embora tenham sido verificados picos de crescimento em anos mais chuvosos.Cryptomeria japonica is indigenous to the temperate region of Japan, where it is known as \u2018sugi\u2019. In Brazil, the plantation of this species is recommended for the highlands and cold regions in the southern, where it is well adapted to the edaphoclimatic conditions. The aim of the study was to evaluate the correlation between meteorological variables and growth of a 25 years old Cryptomeria japonica stand. Cross-sectional discs from 30 different trees were collected, within all diametric classes. After dried and sanded, annual rings were measured and correlated with meteorological data by dendrochronological analysis tools. The growth series showed an intercorrelation of 0.668. The radial growth of the species was positively influenced by the minimum temperature of September and by the medium temperature of May. There was no correlation between growth and precipitation, although peaks of growth were observed in years with high precipitation

MANEJO DA FLORESTA OMBRÓFILA MISTA A PARTIR DA DISTRIBUIÇÃO DIAMÉTRICA: UMA REVISÃO BIBLIOGRÁFICA

A diminuição expressiva da área de ocorrência da Floresta Ombrófila Mista (FOM) ocorreu principalmente devido à intensa exploração madeireira de espécies, como a Araucaria angustifolia. A avaliação dos fragmentos submetidos a distúrbios antrópicos de diferentes intensidades e natureza, identificou fortes diferenciações florísticas e estruturais na vegetação. O conhecimento das características estruturais, como a projeção da distribuição diamétrica no tempo, é de real importância para o manejo das florestas naturais, definindo intervenções que assegurem a sustentabilidade. Com o objetivo de apresentar formas de se obter a distribuição diamétrica, a presente revisão baseou-se em mais de 20 referências, após seleção do levantamento de publicações científicas. A elaboração dos resultados da pesquisa foi dividida em duas partes, mostrando inicialmente cada método e posteriormente seus respectivos resultados. No geral, fragmentos da FOM submetidos ao corte seletivo podem recuperar suas variáveis estruturais em poucas décadas. No entanto, nota-se que todos os parâmetros apresentam baixo incremento, podendo estar relacionado à falta de condução das florestas nativas ou exploração desordenada. Quanto a A. angustifolia, essa vem diminuindo sua participação na floresta, com a tendência de as folhosas aumentarem. Conclui-se que há diversos métodos para se obter a distribuição diamétrica de uma floresta, tendo a necessidade da continuação dos estudos para que no futuro seja possível a determinação de um ciclo de manejo sustentável que priorize a valorização dessa formação florestal e do bioma como um todo

ASPECTOS DENDROMÉTRICOS E SILVICULTURAIS DE UM POVOAMENTO DE Cunninghamia lanceolata NO SUL DO BRASIL

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