629 resultados para Eucalyptus urophylla


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Individual data of basic density and volume of wood, pulp kappa number, soluble lignin, cost of pulping process as well as gravimetric gross yield of pulping process were used from 64 trees of Eucalyptus grandis W. Hill ex Maiden from a commercial population at Lençóis Paulista, SP. The Eucalyptus grandis's seeds were originally from a Seed Production Area (SPA) of Duratex S/A at Botucatu, SP. Obtained data were quantified considering objective of maximization no-bleaching pulp and volume and mass wood restriction, mass of residual and soluble lignin, planted area and pulping process cost. it has also been aimed a selection method for matrix trees through mathematical programming techniques. Obtained strategy maximized the economical result, selected matrix trees and followed all limits of technological and organizing productivities imposed by the company. It also aimed the production of no-bleaching pulp within the planned time.

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The buttonweed (Spermacoce latifolia) is becoming a plant among the most current infesting eucalypts plantation in State of São Paulo due to the continual use of same herbicides and control methods. Owing this, this work aimed to evaluate the effects of periods of company and control of S. Iatifolia on the initial growth of Eucalyptus grandis, planted in winter and summer. Only one seedling of Eucalyptus was planted in amianthus cement box and submitted for crescent periods of company and control of S. Iatifolia (0, 20, 60 and 80 days in competition or not). The densities of plants of S. Iatifolia were 4 and 16 plants per m 2 (under winner and summer conditions). The experimental period was 100 days after the planting (DAP). The experimental design for both experiments was the completely randomized blocks (CRB) with ten treatments and four replicates. The results of plant high, stem diameter, dries weights and leaf area showed that the before interference period (BIP), whole period of prevention for interference (WPPI) and critical period of prevention for interference (CPPI) were 40, 60, and 60 DAR, respectively, under winner conditions. Under summer conditions, the WPPI and CPPI were 20, 80 and 20 to 80 DAR.

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Phylogenetio relationships between Eucalyptus species, subgenus Symphyomyrtus (sections Adnataria, Exsertaria, Maldenaria, and Transversaria), and Corymbia species (sections Politaria and Ocharia) were established based on the sequence of Internal transcribed rDNA spacers (ITS1 and ITS2). The species analyzed were obtained from a collection kept in Brazil. Fragments obtained using primers ITS1 and ITS2 were sequenced and part of the sequence of ITS1 and ITS2 and the complete sequence of 5.8S rDNA were used in the analysis. ITSs and 5.8S rDNA sequences from E. globulus ssp. globulus and A. bakeri (Genus Angophora) were downloaded from the Genbank database and included in the analysis. Psidlum guajava was the selected outgroup used. The sequence alignment and a Neighbor-joining tree were obtained using Clustal X. Few variations were detected in the 5.8S rDNA sequences obtained, occurring mainly between Eucalyptus and Corymbia, thus defining these genera. Variations in ITS sequences occurred in all investigated species. Phylogenetic analysis showed a clear separation between the genera Corymbia and Eucalyptus. A bakeri was more closely related to species belonging to genus Corymbia. Regarding the subgenus Symphyomyrtus (Genus Eucalyptus), only species from section Maidenaria grouped together according to their common section. This could have been caused by the removal of natural reproductive barriers when these species were introduced In Brazil, with a consequent Increase in the rate of interspecific crossings and Introgression events.

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This study evaluate the native species naturally regenerating in Eucalyptus saligna stand understory. This stand is located at Itatinga Experimental Station, of the Forest Sciences Department (ESALQ/USP). The experimental area encompasses two sites separated from each other around 250 m, differing 30 m in altitude. These two sites are different mainly in land slope and soil fertility and soil hydric retention capacity. Eight permanent plots of 625 m2 in each site were randomly sampled. The woody species Individuals with height equal or bigger than 1,5 m and the Eucalyptus saligna coppicings were surveyed in each plot. A total of 107 species were Identified and 7 species were common to both sites, distributed into 72 genera and 34 families. Based upon the results It is possible to conclude that the Eucalyptus saligna trees do not preclude the natural regeneration of the native species in the stand understory, however the floristic structure of the community is also influenced by edaphic factors and vicinity of seed sources.

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Some 255 birds were recorded between 1982-2001 in and near a 2314-ha Horto of old eucalyptus plantations with native understory and a lake, near Rio Claro, in central São Paulo, Brazil. This is close to the 263 recorded in and around a ten-times smaller nearby 230-ha woodlot of semideciduous forest. Different species were 44, for a total of 307 in both areas. One hundred and fifty nonvagrant forest and border species were recorded in 1982-86, a number close to the 152 in the small native woodlot. With dry years and logging of plots in 1985-93, 21 of the 150 species were lost, 42 species decreased in numbers, 49 were stable, 19 increased (15 being border species), and 5 entered (one of dry forest and 4 of borders), so 129 species remained in 1996-2001 compared to 133 in the native woodlot. Open-area birds were 33, versus 50 in better-checked grassy swales in sugar cane near the natural woodlot, for a total of 53. Several species, like some border ones, did not enter the open but isolated and mowed interior lake area, or took years to do so. Water and marsh birds were 46 versus 40 in smaller creeks and ponds near the natural woodlot (total, 55) but many were migrants or infrequent visitors using distant areas, and perhaps should be counted as 0.1-0.9 local species rather than 1 species. Use of this more accurate method would reduce waterbird totals by 14 species in the Horto and by 11 around the native woodlot. I also recommend longer censusing at the edges in large woodlots or many edge species will be recorded only in small fragments of habitat. Several species increased and others decreased with occasional cat-tail and water-lily cleanups at the lake. A forested corridor between the Horto and natural woodlot is recommended, with old eucalyptus left to provide flowers for hummingbirds.

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The alkalophilic Bacillus circulans D1 was isolated from decayed wood. It produced high levels of extracellular cellulase-free xylanase. The enzyme was thermally stable up to 60°C, with an optimal hydrolysis temperature of 70°C. It was stable over a wide pH range (5.5-10.5), with an optimum pH at 5.5 and 80% of its activity at pH 9.0. This cellulase-free xylanase preparation was used to biobleach kraft pulp. Enzymatic treatment of kraft pulp decreased chlorine dioxide use by 23 and 37% to obtain the same kappa number (κ number) and brightness, respectively. Separation on Sephadex G-50 isolated three fractions with xylanase activity with distinct molecular weights.

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Territorial behavior in hummingbirds minimizes competition through aggressive interactions, resulting in a dominance hierarchy among species and individuals. Interactions among seven hummingbird species visiting flowering eucalyptus in the Floresta Estadual near Rio Claro, São Paulo, in southeastern Brazil, were studied. Dominance was determined by weight and size with the largest species being the most dominant. Time spent in defense and the number of aggressive interactions were greater than recorded in literature, perhaps due to the relatively greater density of hummingbirds in the study area. Daily activity patterns differed among dominant and subordinate species, but were not correlated with either the quantity of available nectar or with nectar sugar concentration.

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A field trial was conduced in Piratininga, São Paulo State, Brazil, from August to 1991 to May 1999, aiming to study the effects of weed interference on the productivity of Eucalyptus grandis W. Hill Ex Maiden. The experimental design was complete randomized blocks with four replications. The treatments consisted of different extensions and times of the weed free period. The weed free periods were divided in two groups. In the first one, the weed free period were from the Eucalyptus planting to 28, 56, 112, 140, 168, 224, 278 and 360 days. In the second group the weed free period began at 0, 28, 56, 112, 140, 168, 224 and 278 days after the planting and finished at 364 days. The main weeds were Brachiaria decumbens and Brachiaria brizantha. The eucalypt plants were strong susceptive at weed interference at 12 months after planting, it was showing PAI of 12 and 6 days, when to consider 2 and 5% reduction on height. Although, to assure crop productivity at Piratininga it was necessary to maintain a weed free period of to 364 and 365 days after planting (PTPI) at 12 months, 194 and 166 days after planting at 24 months, 188 and 130 days after planting at 36 months, 88 and 54 days after planting at 48 months and 155 and 133 days after planting at 78 months, when to consider 2 an 5% reduction on heigth. But, if when to consider the DAP, the PTPI was 242 and 200 days after planting at 24 months, 208 and 153 days after planting at 36 months, 224 and 150 days after planting at 48 months and 134 and 119 days after planting at 78 months. Although when to consider the wood volume it was necessary to keep the weed free from the planting to 153 and 142 days at 36 months after planting, 99 and 91 days at 48 months after planting and 92 and 72 days at 78 months after planting (crop). However, in area to suggest the recuperation the eucalypt plants at weed Interference.

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In order to verify the effect of Panicum maximum plant density on the initial growth of Eucalyptus grandis plants, one assay was conducted under semi-controlled conditions of soil fertility and humidity. Dark red Latossol, collected from the arable layer, was used as substrate in 50 liters amianthus cement boxes. One seedling of Eucalyptus was planted in each box. Fifteen days later, seedlings of P. maximum were transplanted on the same box. The treatments consisted of 0, 4, 8, 12, 16 and 20 plants of P. maximum per m 2. The experimental design was the complete randomized design, with six treatments and eight replicates for P. maximum. One hundred and ten and 190 days after transplanting, Eucalyptus plants grown among P. maximum showed an average reduction of 30.80 and 46.55% stem diameter, 25.10 and 22.50 plant high, 40.18 and 31.29% stem dry weight, 61.32 and 54.06% branch dry weight, 53.72 and 51.82% root dry weight, 44.62 and 38.50% leaf dry weight, 22.51 and 23.16 branch number, 20.72 and 19.97% leaf number, and 33.88 and 17.05% leaf area, respectively.

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It had been studied the dimensional variations Pinus caribæa var. hondurensis and Eucalyptus grandiswood, emphasizing the axial, radial, tangential and volumetric shrinkage. The results had shown that the volumetric shrinkage of Pinus and Eucalyptus varied according to an exponential curve, R V=R Vmaxe -ku. The total or maximum volumetric shrinkage showed a linear behavior with the specific gravity on basis of ovendry mass and volume and the same behavior as respect of the specific gravity, where the adjusted equations were, respectively: R vmax = 3,01 + 19,15,oo e R vmax = 1,96 + 24,28,ob. It was also verified that the tangential shrinkage was 1,3 times greater than the radial one and 9,0 times greater than the axial one.

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E grandis seedlings of Bofete progeny, cultivated in nurseries of Eucatex Florestal, were collected at ages of 55, 69, 83, and 97 days, separated into leaves, stem, and roots. The seedlings were then placed in identified paper bags, and oven-dried until weight became constant. They were then weighed and chemically analyzed for the determinate of dry matter production, concentrations and accumulation of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn in the several seedling ages. The distribution of total dry matter weight complied with the following descending order: leaf > stem > roots. Conversely to expectations, the highest concentrations of nutrients occurred in leaves for N and Mn only. Seedling hardened process resulted in N and S deficiency. The sequence of macronutrient concentration in seedlings at the time of shipment was the following: leaf > root > stem for N; root = stem > leaf for P; leaf = root = stem for K; stem > root > leaf for Ca; root > leaf > stem for Mg and S. All macronutrient concentrations in organs decreased with age, except for Ca. Concentrations of Cu, Fe, and Zn in all seedling specimens decreased with age. The sequence of micronutrient concentrations in seedling specimens at the time of shipment was the following: root >stem = leaf for B; root > stem > leaf for Cu and Fe; root > leaf > stem for Zn, and leaf > stem > root for Mn. At the time of shipment, at 97 days of age, K was the most extracted macronutrient of all, followed in a descending order by Ca, N, Mg, P, and e S. At the end of the seedling production rotation, Mn was the most extracted micronutrient, followed by Fe, Zn, Cu, and B.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The juvenile wood has peculiar characteristics from the anatomical structure and physical-mechanical properties, considering these aspects the knowledge of the wood is essential for wood adequate utilization. The aim of this work was to determinate the zone of juvenile wood of pith-bark direction in Eucalyptus citriodora. The juvenile and mature wood zones were determined across fiber length measurement in various height in the tree stem. Results showed that juvenile wood zone occurs approximately up to the 45 at 55 mm from the pith.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)