Desenvolvimento e avaliação de pulverizador florestal com detecção eletrônica de plantas daninhas e aplicação em doses variáveis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Tissue culture of forest trees: Clonal multiplication of Eucalyptus grandis L

Axillary shoot proliferation was obtained using explants of Eucalyptus grandis L. juvenile and mature stages on a defined medium. Murashige and Skoog medium (MS) supplemented with benzyladenine (BA), naphthalene acetic acid (NAA) and additional thiamine. Excised shoots were induced to root on a sequence of three media: (1) White's medium containing indoleacetic acid (IAA), NAA and indole butyric acid; (IBA), (2) half-strength MS medium with charcoal and (3) half-strength MS liquid medium. The two types of explants differed in rooting response, with juvenile-derived shoots giving 60% rooting and adult-derived ones only 35%. Thus, the factors limiting cloning of selected trees in vitro are determined to be those controlling rooting of shoots in E. grandis.

Growth and species interactions of Eucalyptus pellita in a mixed and monoculture plantation in the humid tropics of north Queensland

This study investigated whether mixed-species designs can increase the growth of a tropical eucalypt when compared to monocultures. Monocultures of Eucalyptus pellita (E) and Acacia peregrina (A) and mixtures in various proportions (75E:25A, 50E:50A, 25E:75A) were planted in a replacement series design on the Atherton Tablelands of north Queensland, Australia. High mortality in the establishment phase due to repeated damage by tropical cyclones altered the trial design. Effects of experimental designs on tree growth were estimated using a linear mixed-effects model with restricted maximum likelihood analysis (REML). Volume growth of individual eucalypt trees were positively affected by the presence of acacia trees at age 5 years and this effect generally increased with time up to age 10 years. However, the stand volume and basal area increased with increasing proportions of E. pellita, due to its larger individual tree size. Conventional analysis did not offer convincing support for mixed-species designs. Preliminary individual-based modelling using a modified Hegyi competition index offered a solution and an equation that indicates acacias have positive ecological interactions (facilitation or competitive reduction) and definitely do not cause competition like a eucalypt. These results suggest that significantly increased in growth rates could be achieved with mixed-species designs. This statistical methodology could enable a better understanding of species interactions in similarly altered experiments, or undesigned mixed-species plantations.

Evaluation of the kinetics of xylose formation from dilute sulfuric acid hydrolysis of forest residues of Eucalyptus grandis

Dilute acid hydrolysis studies were performed on forest residues of Eucalyptus grandis, in a cylindrical reactor of stainless steel. The kinetics of this hydrolysis reaction was investigated employing 0.65% sulfuric acid, a residue/acid solution ratio of 1/9 (w/w), temperatures of 130, 140, 150, and 160 degrees C, and reaction times in the range 20-100 min. The results showed that, under the optimized conditions of acid hydrolysis employed in this study, the variables temperature and reaction time had a strong influence on hemicellulose removal and a small influence on the degree of lignin and cellulose removal. The highest xylose extraction yield was 87.6% attained at 160 degrees C, after 70 min reaction time, simultaneously with the formation of decomposition products, namely 2.8% acetic acid, 0.6% furfural, and 0.06% 5-hydroxymethylfurfural. A similar xylose extraction yield (82.8%) was observed at 150 degrees C after 100 min, with the formation of 3.2% acetic acid, 1.0% furfural, and 0.07% 5-hydroxymethylfurfural. The kinetic parameters determined at 130, 140, 150, and 160 degrees C for degradation of xylan present in the hemicellulose of the eucalyptus forest residue during the formation of xylose were the first-order reaction rate constants (k) for each temperature, 1.22 x 10(-4), 2.12 x 10(-4), 5.43 x 10(-4), and 9.05 x 10(-4) s(-1), respectively, and an activation energy (E-a) of 101.3 kJ mol(-1).

Quality of wood and pulp from a clone of Eucalyptus grandis planted at three locations

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

Native and exotic pests of Eucalyptus: A worldwide perspective.

Eucalyptus species, native to Australia, Indonesia, the Philippines, and New Guinea, are the most widely planted hardwood timber species in the world. The trees, moved around the globe as seeds, escaped the diverse community of herbivores found in their native range. However, a number of herbivore species from the native range of eucalypts have invaded many Eucalyptus-growing regions in North America, Europe, Africa, Asia, and South America in the last 30 years. In addition, there have been shifts of native species, particularly in Africa, Asia, and South America, onto Eucalyptus. There are risks that these species as well as generalist herbivores from other parts of the world will invade Australia and threaten the trees in their native range. The risk to Eucalyptus plantations in Australia is further compounded by planting commercially important species outside their endemic range and shifting of local herbivore populations onto new host trees. Understanding the mechanisms underlying host specificity of Australian insects can provide insight into patterns of host range expansion of both native and exotic insects.

Rainfall infiltration and soil hydrological characteristics below ancient forest, planted forest, and grassland in a temperate northern climate

How rainfall infiltration rate and soil hydrological characteristics develop over time under forests of different ages in temperate regions is poorly understood. In this study, infiltration rate and soil hydrological characteristics were investigated under forests of different ages and under grassland. Soil hydraulic characteristics were measured at different scales under a 250 year old grazed grassland (GL), a six (6 yr) and 48 (48 yr) year old Scots pine (Pinus sylvestris) plantation, remnant 300 year old individual Scots pines (OT) and a 4000 year old Caledonian Forest (AF). In-situ field saturated hydraulic conductivity (Kfs) was measured and visible root:soil area was estimated from soil pits. Macroporosity, pore structure, and macropore connectivity were estimated from X-ray tomography of soil cores, and from water-release characteristics. At all scales the median values for Kfs, root fraction, macro-porosity and connectivity values tended to AF > OT > 48 yr > GL > 6 yr, indicating that infiltration rates and water storage increased with forest age. The remnant Caledonian Forest had a huge range of Kfs (12 to > 4922 mm h-1), with maximum Kfs values 7 to 15 times larger than 48-year-old Scots pine plantation, suggesting that undisturbed old forests, with high rainfall and minimal evapotranspiration in winter, may act as important areas for water storage and sinks for storm rainfall to infiltrate and transport to deeper soil layers via preferential flow. The importance of the development of soil hydrological characteristics under different aged forests is discussed.

Fluxes of CO(2) above a plantation of Eucalyptus in southeast Brazil

Eddy-covariance measurements of net ecosystem exchange of CO(2) (NEE) and estimates of gross ecosystem productivity (GEP) and ecosystem respiration (R(E)) were obtained in a 2-4 year old Eucalyptus plantation during two years with very different winter rainfall In the first (drier) year the annual NEE GEP and RE were lower than the sums in the second (normal) year and conversely the total respiratory costs of assimilated carbon were higher in the dry year than in the normal year Although the net primary production (NPP) in the first year was 23% lower than that of the second year the decrease in the carbon use efficiency (CUE = NPP/GEP) was 11% and autotrophic respiration utilized more resources in the first dry year than in the second normal year The time variations in NEE were followed by NPP because in these young Eucalyptus plantations NEE is very largely dominated by NPP and heterotrophic respiration plays only a relatively minor role During the dry season a pronounced hysteresis was observed in the relationship between NEE and photosynthetically active radiation and NEE fluxes were inversely proportional to humidity saturation deficit values greater than 0 8 kPa Nighttime fluxes of CO(2) during calm conditions when the friction velocity (u) was below the threshold (0 25 ms(-1)) were estimated based on a Q(10) temperature-dependence relationship adjusted separately for different classes of soil moisture content which regulated the temperature sensitivity of ecosystem respiration (C) 2010 Elsevier B V All rights reserved

Selection of fungi for accelerated decay in stumps of Eucalyptus spp.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

RAPD analysis of genetic variability in a multiprovenance base population of Eucalyptus grandis hill ex maiden

Este estudo visou avaliar a variabilidade e distância genética dentro de uma população-base de melhoramento genético de Eucalyptus grandis. A avaliação da variabilidade genética tem como objetivos principais analisar a base genética da população-base e montar um banco de dados marcadores moleculares da população em análise. Essa população é formada por 327 indivíduos, principalmente das procedências de Coff's Harbour, Atherton e Rio Claro. Devido à heterozigosidade natural dessa população, ela pode ser dividida em diversas subpopulações, de acordo com a latitude e longitude de origem; e dentro de subpopulações, em função do grau de melhoramento genético já realizado do material analisado no Brasil. Isso permitiu avaliar quanto da variabilidade detectada dentro da população-base foi devido a esses fatores: procedência e grau de melhoramento. A aplicação da técnica RAPD permitiu avaliar 70 locos polimórficos, que foram analisados utilizando-se o coeficiente de Jaccard, o que resultou em matrizes de similaridade genética entre os indivíduos. Os dados de similaridade genética posteriormente foram submetidos à análise estatística. Osdados indicaram que a população-base apresenta ampla base genética, com média de similaridade genética de 0,328. O subgrupo denominado Região 3, composto por material selvagem da macrorregião de Atherton, juntamente com material de APS da macrorregião de Coff's Harbour, foi um dos que mais contribuíram para a ampla base genética da população-base. Foi possível detectar diferença estatística entre as populações selvagens das procedências de Atherton e Coff's Harbour, assim como entre essas procedências e a de Rio Claro.

Seasonal and spatial species richness variation of dung beetle (Coleoptera, Scarabaeidae s. str.) in the Atlantic Forest of southeastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estimation of outcrossing rate in a breeding population of Eucalyptus urophylla with dominant RAPD and AFLP markers

Eucalyptus breeding is typically conducted by selection in open-pollinated progenies. As mating is controlled only on the female side of the cross, knowledge of outcrossing versus selling rates is essential for maintaining adequate levels of genetic variability for continuous gains. Outcrossing rate in an open-pollinated breeding population of Eucalyptus urophylla was estimated by two PCR-based dominant marker technologies, RAPD and AFLP, using 11 open-pollinated progeny arrays of 24 individuals. Estimated outcrossing rates indicate predominant outcrossing and suggest maintenance of adequate genetic variability within families. The multilcous outcrossing rate (t(m)) estimated from RAPD markers (0.93 +/- 0.027), although in the same range, was higher (alpha > 0.01) than the estimate based on AFLP (0.89 +/- 0.033). Both estimates were of similar magnitude to those estimated for natural populations using isozymes. The estimated Wright's fixation index was lower than expected based on t, possibly resulting from selection against selfed seedlings when sampling plants for the study. An empirical analysis suggests that 18 is the minimum number of dominant marker loci necessary to achieve robust estimates of t,. This study demonstrates the usefulness of dominant markers, both RAPD and AFLP, for estimating the outcrossing rate in breeding and natural populations of forest trees. We anticipate an increasing use of such PCR-based technologies in mating-system studies, in view of their high throughput and universality of the reagents, particularly for species where isozyme systems have not yet been optimized.

Estimating hardness of eucalyptus wood with a portable hardness tester

More than 80% of the 29600 km of the Brazilian railroad mesh employs wooden sleepers. The problem of hard availability of native wood for this purpose leads to the alternative use of reforestation species to produce sleepers. Considering the great difficulty to, in field condition, evaluate characteristics that are of major importance to define its suitability to sleeper production the Research Group on Forest Products from FCA/UNESP - Brazil had developed equipment for field evaluation of hardness in wood - Portable Hardness Tester. This paper reports the functional validation tests, performed with different species of Eucalyptus. Results revealed the equipment great functionality, easy-to-use characteristics and applicability to Eucalyptus wood. Moderate to strong relationships between laboratory and validated values of hardness were found. The best validation model was obtained using the data provided by the experimental dispositive 3 (R2=0.74 and SSE= 7.71 kJ/m2) while the experimental dispositive 1 gave the worse validation (R2=0.55 and SSE= 13.46 kJ/m2).

Biomass yield and calorific value of six clonal stands of Eucalyptus urophylla S. T. Blake cultivated in Northeastern Brazil

A demanda mundial por energia limpa e sustentável tem aumentado nos últimos anos. Uma das alternativas é a biomassa, incluindo os plantios florestais, com destaque, no Brasil, para o gênero Eucalyptus spp., que, atualmente, possui diversos clones selecionados para a produção de energia. Em razão da diferença na adaptação dos clones aos diferentes ambientes, há necessidade de estudos específicos para avaliar a produção de energia para determinada região. Objetivou-se, neste estudo, determinar dentre seis clones de Eucalyptus urophylla S. T. Blake analisados, aqueles com maior potencial para a produção de biomassa e energia para a região Centro Sul do Maranhão (Grajaú). Os clones foram avaliados com 41 meses de idade, plantados em espaçamento de 4 x 3 m, e distribuídos em delineamento inteiramente casualizado, com cinco repetições. Cada parcela experimental era composta por 100 árvores. Foram determinadas a produção e a alocação de biomassa de cada parte da árvore e o poder calorífico de casca e do lenho. Dos seis clones estudados, dois se destacaram tanto na produção de biomassa, quanto para a geração de energia, sendo superiores em até 27 % em comparação com o clone de menor rendimento.

Substrates and controlled-release fertilizations on the quality of eucalyptus cuttings

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