Plagas exóticas de importância en Eucalyptus en Brasil.

2008

Performance and quality of wood in a clone of Eucalyptus in monoculture and silvipastoral system.

Este trabalho foi desenvolvido com o objetivo de avaliar e comparar o desempenho e as variações na qualidade da madeirade árvores de eucalipto implantadas em sistema silvipastoril e em monocultivo. Os dados foram coletados em 13 árvores amostras aos 36 meses de idade, selecionadas em função do intervalo de confiança da média dos diâmetros a altura do peito (DAP), e da posição das árvores na faixa de plantio no sistema silvipastoril, com face de exposição sul, norte e central. Foram avaliadas as variáveis DAP, altura total e altura comercial, volume e conicidade do tronco, densidade básica e deslocamento da medula. Concluiu-se que no sistema silvipastoril as árvores apresentaram maior DAP, menor altura total e maior conicidade do tronco que no monocultivo. O DAP não diferiu em relação à posição na faixa de plantio, porém as árvores com face de exposição norte foram mais baixas e cônicas. A densidade básica e o deslocamento da medula não foram influenciados pelo sistema de cultivo.

Variação longitudinal do poder calorífico de clones de Eucalyptus sp.

2016

Influence of nitrogen sources on the enzymatic activity and grown by Lentinula edodes in biomass Eucalyptus benthamii.

Lignocelulose é o componente mais abundante do meio ambiente e recurso orgânico renovável no solo. Alguns fungos filamentosos têm desenvolvido a habilidade de degradar e utilizar celulose, hemicelulose e lignina como fonte de energia. O objetivo deste trabalho foi analisar o efeito de três fontes de nitrogênio (sulfato de amônio, nitrato de potássio e farelo de soja) na atividade enzimática de Lentinula edodes EF 50 utilizando como substrato serragem de E. benthamii. Foi aplicado um planejamento experimental de mistura com três repetições no ponto central constituído de sete tratamentos (T) de iguais concentrações em nitrogênio de sulfato de amônia, nitrato de potássio e farinha de soja cozida. Foram determinadas a atividade enzimática da avicelase, carboximetilcelulase, β-glicosidase, xilanases e manganês peroxidase. Foram avaliados o teor de umidade, pH, atividade de água (aw) e análise qualitativa do crescimento micelial em 8 tempos de cultivo. Os resultados mostraram efeito negativo na produção das enzimas nos tratamentos com máxima concentração de sulfato de amônia e nitrato de potássio. Os tratamentos com farinha de soja cozida expressaram maiores atividades enzimáticas, nos tempos de 3, 6 e 9 dias de cultivo exceto na atividade do manganês peroxidase. A maior produção foi observada no tratamento com sulfato de amônia e farinha de soja cozida (83.86 UI.L?1) em 20 dias de cultivo.

Modelagem de biomassa por unidade de área em plantações de Eucalyptus no Estado de Minas Gerais.

Este trabalho teve como objetivo estimar a quantidade de biomassa seca em plantios de Eucalyptus no estado de Minas Gerais, a partir de resultados de 244 parcelas de inventário florestal, considerando variações de qualidade do sítio, área basal e idade entre 2 e 8 anos. Foi estabelecida a classificação de sítio, com ajuste de equação utilizando os dados de idade e altura dominante. A biomassa total por hectare foi calculada multiplicando-se o volume por hectare pela densidade da madeira de Eucalyptus grandis e por um fator de expansão de biomassa. Avaliando-se a correlação entre biomassa total por hectare e variáveis ambientais e dendrométricas, verificou-se que a área basal e o índice de sítio foram as duas variáveis do povoamento de correlação mais alta, 0,93 e 0,64, respectivamente. Doze modelos foram ajustados para representar a quantidade de biomassa total por hectare tendo como variáveis independentes a área basal, o índice de sítio e a idade, bem como combinações entre estas. O modelo que apresentou melhor ajuste e precisão foi: Bs = exp[−6,7518 + 0,9567 × ln(G) + 0,0388 × ln?(G) + 4,0732 × ln(IS) − 0,4799 × ln?(IS)] × 1,0020, com R²ajustado de 0,955 e Syx% de 5,29%, e indicou valores de estoque de biomassa entre 39,7 e 174,9 Mg.ha-1, para área basal entre 8,9 e 27,9 m2.ha-1. A aplicação do modelo ajustado, com as variáveis índice de sitio e área basal por hectare, pode estimar de maneira prática e precisa a biomassa total por hectare, por utilizar variáveis de simples obtenção e por ter sido gerada a partir de um conjunto de dados com pouca variabilidade atribuída ao material genético.

Thermal tool for evaluation of essential oils of Eucalyptus spp susceptible and resistant to Glycaspis brimblecombei attack.

Eucalyptus spp genus is economically important to different industry fields. There are pests that damage the development of eucalypts and Glycaspis brimblecombei, a sap-sucking insect, is one of them. Studies about this insect attack to the eucalypts showed preferences. This work aim was to compare the preferences of the insect with thermoanalytical characteristics of different eucalypts (susceptible, less susceptible and resistant to Glycaspis brimblecombei) essential oils. The leaves of six species of Eucalyptus were crushed and the essential oil was extracted using Clevenger apparatus. The Shimadzu DTG-60H was used to analyze the samples. The results showed that the samples from more susceptible eucalypts had total mass loss at about 124ºC to 156ºC, lower than samples from more resistant eucalypts (from 168ºC to 175ºC). Furthermore, the study suggests that the susceptibility or the resistance of eucalypts to the pest may be related to their essential oil composition and concentration of monoterpenes and sesquiterpenes.

Soil carbon and nitrogen in pasture soil reforested with eucalyptus and guachapele.

Apesar de os teores de matéria orgânica serem normalmente baixos em solos arenosos, ela é responsável por quase a totalidade da CTC, armazenamento de água e disponibilidade de nutrientes desses solos. A avaliação de sistemas de exploração florestais alternativos, com vistas em incrementar a acumulação de C e N, devem ser incentivados. Este estudo compara plantios puros e mistos de Eucalyptus grandis e Pseudosamanea guachapele, leguminosa fixadora de N2, em relação os estoques de C e N do solo. Os plantios foram realizados em áreas anteriormente manejadas com Panicum maximum num Planossolo, que, por pelo menos dez anos, não recebeu qualquer fertilizante. Para estimar o C e o N estocado, foram retiradas amostras das camadas de 0-2,5; 2,5-5,0; 5,0-7,5; 7,5-10,0; 10,0-20,0 e 20,0-40,0 cm tanto nos plantios puros e mistos, quanto na área de pasto. A técnica da abundância natural do 13C foi utilizada na estimativa do C originado das árvores nos 10 cm superficiais. Os estoques de C e N, no plantio misto atingiu valores de 23,83 e 1,74 Mg ha-1, respectivamente. Nos puros, de guachapele e eucalipto, e no pasto os estoques de C estimados foram de 14,20; 17,19 e 24,24 Mg ha-1, respectivamente. Para os mesmos tratamentos, os estoques de N foram estimados em 0,83; 0,99 e 1,71 Mg ha-1, respectivamente. Mais de 40 % do C do solo sob o plantio misto foram estimados como sendo derivados das árvores, enquanto nos plantios puros de eucalipto e guachapele, a contribuição do C das árvores ficou em 19 e 27 %, respectivamente. Esses resultados evidenciam que a presença da leguminosa no plantio consorciado aumenta os estoques de C e N do solo.

Biological nitrogen fixation and nutrient release from litter of the guachapele leguminous tree under pure and mixed plantation with eucalyptus.

A Pseudosamanea guachapele (guachapele), leguminosa arbórea fixadora de nitrogênio, é uma alternativa para plantios florestais mistos nos trópicos. Como são escassas as informações sobre a espécie em plantios mistos de eucalipto em condições edafoclimáticas brasileiras, foi conduzido um experimento no qual objetivou-se avaliar a contribuição da fixação biológica de nitrogênio para a guachapele e a velocidade de decomposição e de liberação de nutrientes de folhas senescentes de eucalipto e guachapele (oriundas dos plantios puros e consorciado). A porcentagem de N derivado da atmosfera (% Ndfa) foi estimada comparando-se a abundância natural de 15N ( 15N, ) nos tecidos da guachapele com a observada nos tecidos do Eucalyptus grandis, espécie não fixadora, ambas com sete anos de idade. A constante de decomposição (k) e a meia-vida (t1/2) de serapilheira foram estimadas utilizando-se o modelo exponencial aplicado aos dados oriundos de coletas de litterbags. A estimativa da %Ndfa para guachapele, em condições de plantio puro, variou de 17 a 36%, enquanto que, em condições de plantio consorciado, foi de 35 a 60 %. A concentração de N nas folhas senescentes estava positivamente relacionada com a taxa de decomposição, sendo essa decrescente da guachapele para o eucalipto. A t1/2 dos resíduos diferiu significativamente (p < 0.05), sendo de 148, 185 e 218 dias para as folhas de guachapele, mistura das duas espécies e eucalipto, respectivamente. A liberação dos nutrientes (principalmente N, K e Mg) das folhas seguiu a mesma ordem da t1/2 devido à qualidade inicial das mesmas. Os resultados indicam que a guachapele pode beneficiar o plantio misto pela adição de N e por meio da intensificação da decomposição da serapilheira.

Evaluation of the throughfall and stemflow nutrient contents in mixed and pure plantations of Acacia mangium, Pseudosamenea guachapele and Eucalyptus grandis.

A interceptação da chuva pela copa das florestas tem grande relevância no ciclo biogeoquímico de nutrientes nos solos de baixa fertilidade sob florestas nativas e plantadas. Entretanto, pouco se sabe sobre as modificações na qualidade dessa água e no balanço hidrológico após a interceptação pela copa do eucalipto sob condições de plantios puros e mistos com leguminosas, no Brasil. Amostras de água de chuva (RF), de precipitação interna (TF) e de escoamento pelo tronco (SF), foram coletadas e analisadas quimicamente em plantios puros de mangium (espécie fixadora de nitrogênio atmosférico - EFN), guachapele (EFN) e eucalipto (espécie não fixadora de nitrogênio - ENFN) e consorciados com guachapele e eucalipto, em Seropédica, Rio de Janeiro. Nove coletores de escoamento pelo tronco (colocados em árvores), nove pluviômetros posicionados ao acaso nos plantios e três fora da influência deles foram utilizados no monitoramento durante 5,5 meses. A mangium direcionou 33,4% do total precipitado para o seu tronco. Uma estimativa baseada na correção da média anual precipitada na área (1.213 mm) indicou uma contribuição no aporte de nutrientes (kg ha-1) de 8,42; 0,95; 19,04; 6,74; 4,72; e 8,71 kg ha-1 dos elementos N-NH4+, P, K+, Ca+2, Mg+2 and Na+, respectivamente. A precipitação interna participou com a maior parte da contribuição, em comparação com o escoamento pelo tronco. Os maiores aportes de N-NH4+ (15,03 kg ha-1) e K+ (179,43 kg ha-1) foram observados sob as copas de guachapele em plantio puro. Elevada quantidade de Na+ denota influencia do mar próximo à área experimental. A mangium foi a espécie adaptada à competição por água. Comparativamente ao plantio puro de eucalipto, o plantio misto intensificou a lixiviação de N, Ca e Mg da copa, enquanto o de K e o P aportaram em menores quantidades nesse plantio.

Examining the cause of high inbreeding depression: analysis of whole-genome sequence data in 28 selfed progeny of Eucalyptus grandis.

2016

A pilot study on the effect of indoor particle sources on indoor particle concentration in residential houses

Characterization of indoor particle sources from 14 residential houses in Brisbane, Australia, was performed. The approximation of PM2.5 and the submicrometre particle number concentrations were measured simultaneously for more than 48 h in the kitchen of all the houses by using a photometer (DustTrak) and a condensation particle counter (CPC), respectively. From the real time indoor particle concentration data and a diary of indoor activities, the indoor particle sources were identified. The study found that among the indoor activities recorded in this study, frying, grilling, stove use, toasting, cooking pizza, smoking, candle vaporizing eucalyptus oil and fan heater use, could elevate the indoor particle number concentration levels by more than five times. The indoor approximation of PM2.5 concentrations could be close to 90 times, 30 times and three times higher than the background levels during grilling, frying and smoking, respectively.

Particle number and mass emission factors from combustion of wood samples collected from Queensland forest

Knowledge of particle emission characteristics associated with forest fires and in general, biomass burning, is becoming increasingly important due to the impact of these emissions on human health. Of particular importance is developing a better understanding of the size distribution of particles generated from forest combustion under different environmental conditions, as well as provision of emission factors for different particle size ranges. This study was aimed at quantifying particle emission factors from four types of wood found in South East Queensland forests: Spotted Gum (Corymbia citriodora), Red Gum (Eucalypt tereticornis), Blood Gum (Eucalypt intermedia), and Iron bark (Eucalypt decorticans); under controlled laboratory conditions. The experimental set up included a modified commercial stove connected to a dilution system designed for the conditions of the study. Measurements of particle number size distribution and concentration resulting from the burning of woods with a relatively homogenous moisture content (in the range of 15 to 26 %) and for different rates of burning were performed using a TSI Scanning Mobility Particle Sizer (SMPS) in the size range from 10 to 600 nm and a TSI Dust Trak for PM2.5. The results of the study in terms of the relationship between particle number size distribution and different condition of burning for different species show that particle number emission factors and PM2.5 mass emission factors depend on the type of wood and the burning rate; fast burning or slow burning. The average particle number emission factors for fast burning conditions are in the range of 3.3 x 1015 to 5.7 x 1015 particles/kg, and for PM2.5 are in the range of 139 to 217 mg/kg.

Host searching behaviour of Diachasmimorpha kraussii (Fullaway) (Hymenoptera: Braconidae: Opiinae), a polyphagous parasitoid of Dacinae fruit flies (Diptera: Tephritidae)

Diachasmimorpha kraussii (Hymenoptera: Braconidae: Opiinae) is a koinobiont larval parasitoid of dacine fruit flies of the genus Bactrocera (Diptera: Tephritidae) in its native range (Australia, Papua New Guinea, Solomon Islands). The wasp is a potentially important control agent for pest fruit flies, having been considered for both classical and inundative biological control releases. I investigated the host searching, selection and utilisation mechanisms of the wasp against native host flies within its native range (Australia). Such studies are rare in opiine research where the majority of studies, because of the applied nature of the research, have been carried out using host flies and environments which are novel to the wasps. Diachasmimorpha kraussii oviposited equally into maggots of four fruit fly species, all of which coexist with the wasp in its native range (Australia), when tested in a choice trial using a uniform artificial diet media. While eggs laid into Bactrocera tryoni and B. jarvisi developed successfully through to adult wasps, eggs laid into B. cucumis and B. cacuminata were encapsulated. These results suggest that direct larval cues are not an important element in host selection by D. kraussii. Further exploring how D. kraussii locates suitable host larvae, I investigated the role of plant cues in host searching and selection. This was examined in a laboratory choice trial using uninfested fruit or fruit infested with either B. tryoni or B. jarvisi maggots. The results showed a consistent preference ranking among infested fruits by the wasp, with guava and peach most preferred, but with no response to uninfested fruits. Thus, it appears the wasp uses chemical cues emitted in response to fruit fly larval infestation for host location, but does not use cues from uninfested fruits. To further tease apart the role of (i) suitable and non-suitable maggots, (ii) infested and uninfested fruits of different plant species, and (iii) adult flies, in wasp host location and selection, I carried out a series of behavioural tests where I manipulated these attributes in a field cage. These trials confirmed that D. kraussii did not respond to cues in uninfested fruits, that there were consistent preferences by the wasps for different maggot infested fruits, that fruit preference did not vary depending on whether the maggots were physiologically suitable or not suitable for wasp offspring development, and finally, that adult flies appear to play a secondary role as indicators of larval infestation. To investigate wasp behaviour in an unrestrained environment, I concurrently observed diurnal foraging behaviours of both the wasp and one of its host fly in a small nectarine orchard. Wasp behaviour, both spatially and temporally, was not correlated with adult fruit fly behaviour or abundance. This study reinforced the point that infested fruit seems to be the primary cue used by foraging wasps. Wasp and fly feeding and mating was not observed in the orchard, implying these activities are occurring elsewhere. It is highly unlikely that these behaviours were happening within the orchard during the night as both insects are diurnal. As the final component of investigating host location, I carried out a habitat preference study for the wasp at the landscape scale. Using infested sentinel fruits, I tested the parasitism rate of B. tryoni in eucalyptus sclerophyll forest, rainforest and suburbia in South East Queensland. Although, rainforest is the likely endemic habitat of both B. tryoni and D. kraussii, B. tryoni abundance is significantly greater in suburban environments followed by eucalyptus sclerophyll forest. Parasitism rate was found to be higher in suburbia than in the eucalyptus sclerophyll forest, while no parasitism was recorded in the rainforest. This result suggests that wasps orient within the landscape towards areas of high host density and are not restricted by habitat types. Results from the different experiments suggest that host searching, selection and utilisation behaviour of D. kraussii are strongly influenced by cues associated with fruit fly larval feeding. Cues from uninfested fruits, the host larvae themselves, and the adult host flies play minimal roles. The discussion focuses on the fit of D. kraussii to Vinson’s classical parasitoid host location model and the implications of results for biological control, including recommendations for host and plant preference screening protocols and release regimes.

A study into the permeability and compressibility of Australian bagasse pulp

This is an experimental study into the permeability and compressibility properties of bagasse pulp pads. Three experimental rigs were custom-built for this project. The experimental work is complemented by modelling work. Both the steady-state and dynamic behaviour of pulp pads are evaluated in the experimental and modelling components of this project. Bagasse, the fibrous residue that remains after sugar is extracted from sugarcane, is normally burnt in Australia to generate steam and electricity for the sugar factory. A study into bagasse pulp was motivated by the possibility of making highly value-added pulp products from bagasse for the financial benefit of sugarcane millers and growers. The bagasse pulp and paper industry is a multibillion dollar industry (1). Bagasse pulp could replace eucalypt pulp which is more widely used in the local production of paper products. An opportunity exists for replacing the large quantity of mainly generic paper products imported to Australia. This includes 949,000 tonnes of generic photocopier papers (2). The use of bagasse pulp for paper manufacture is the main application area of interest for this study. Bagasse contains a large quantity of short parenchyma cells called ‘pith’. Around 30% of the shortest fibres are removed from bagasse prior to pulping. Despite the ‘depithing’ operations in conventional bagasse pulp mills, a large amount of pith remains in the pulp. Amongst Australian paper producers there is a perception that the high quantity of short fibres in bagasse pulp leads to poor filtration behaviour at the wet-end of a paper machine. Bagasse pulp’s poor filtration behaviour reduces paper production rates and consequently revenue when compared to paper production using locally made eucalypt pulp. Pulp filtration can be characterised by two interacting factors; permeability and compressibility. Surprisingly, there has previously been very little rigorous investigation into neither bagasse pulp permeability nor compressibility. Only freeness testing of bagasse pulp has been published in the open literature. As a result, this study has focussed on a detailed investigation of the filtration properties of bagasse pulp pads. As part of this investigation, this study investigated three options for improving the permeability and compressibility properties of Australian bagasse pulp pads. Two options for further pre-treating depithed bagasse prior to pulping were considered. Firstly, bagasse was fractionated based on size. Two bagasse fractions were produced, ‘coarse’ and ‘medium’ bagasse fractions. Secondly, bagasse was collected after being processed on two types of juice extraction technology, i.e. from a sugar mill and from a sugar diffuser. Finally one method of post-treating the bagasse pulp was investigated. The effects of chemical additives, which are known to improve freeness, were also assessed for their effect on pulp pad permeability and compressibility. Pre-treated Australian bagasse pulp samples were compared with several benchmark pulp samples. A sample of commonly used kraft Eucalyptus globulus pulp was obtained. A sample of depithed Argentinean bagasse, which is used for commercial paper production, was also obtained. A sample of Australian bagasse which was depithed as per typical factory operations was also produced for benchmarking purposes. The steady-state pulp pad permeability and compressibility parameters were determined experimentally using two purpose-built experimental rigs. In reality, steady-state conditions do not exist on a paper machine. The permeability changes as the sheet compresses over time. Hence, a dynamic model was developed which uses the experimentally determined steady-state permeability and compressibility parameters as inputs. The filtration model was developed with a view to designing pulp processing equipment that is suitable specifically for bagasse pulp. The predicted results of the dynamic model were compared to experimental data. The effectiveness of a polymeric and microparticle chemical additives for improving the retention of short fibres and increasing the drainage rate of a bagasse pulp slurry was determined in a third purpose-built rig; a modified Dynamic Drainage Jar (DDJ). These chemical additives were then used in the making of a pulp pad, and their effect on the steady-state and dynamic permeability and compressibility of bagasse pulp pads was determined. The most important finding from this investigation was that Australian bagasse pulp was produced with higher permeability than eucalypt pulp, despite a higher overall content of short fibres. It is thought this research outcome could enable Australian paper producers to switch from eucalypt pulp to bagasse pulp without sacrificing paper machine productivity. It is thought that two factors contributed to the high permeability of the bagasse pulp pad. Firstly, thicker cell walls of the bagasse pulp fibres resulted in high fibre stiffness. Secondly, the bagasse pulp had a large proportion of fibres longer than 1.3 mm. These attributes helped to reinforce the pulp pad matrix. The steady-state permeability and compressibility parameters for the eucalypt pulp were consistent with those found by previous workers. It was also found that Australian pulp derived from the ‘coarse’ bagasse fraction had higher steady-state permeability than the ‘medium’ fraction. However, there was no difference between bagasse pulp originating from a diffuser or a mill. The bagasse pre-treatment options investigated in this study were not found to affect the steady-state compressibility parameters of a pulp pad. The dynamic filtration model was found to give predictions that were in good agreement with experimental data for pads made from samples of pretreated bagasse pulp, provided at least some pith was removed prior to pulping. Applying vacuum to a pulp slurry in the modified DDJ dramatically reduced the drainage time. At any level of vacuum, bagasse pulp benefitted from chemical additives as quantified by reduced drainage time and increased retention of short fibres. Using the modified DDJ, it was observed that under specific conditions, a benchmark depithed bagasse pulp drained more rapidly than the ‘coarse’ bagasse pulp. In steady-state permeability and compressibility experiments, the addition of chemical additives improved the pad permeability and compressibility of a benchmark bagasse pulp with a high quantity of short fibres. Importantly, this effect was not observed for the ‘coarse’ bagasse pulp. However, dynamic filtration experiments showed that there was also a small observable improvement in filtration for the ‘medium’ bagasse pulp. The mechanism of bagasse pulp pad consolidation appears to be by fibre realignment. Chemical additives assist to lubricate the consolidation process. This study was complemented by pulp physical and chemical property testing and a microscopy study. In addition to its high pulp pad permeability, ‘coarse’ bagasse pulp often (but not always) had superior physical properties than a benchmark depithed bagasse pulp.

Natural enemies of Paropsis atomaria Olivier (Coleoptera: Chrysomelidae) in south-eastern Queensland eucalypt plantations

Abstract A field survey for natural enemies of Paropsis atomaria was conducted at two south-eastern Queensland Eucalyptus cloeziana plantation sites during 2004–2005. Primary egg and larval parasitoids and associated hyperparasitoids were identified to genus or species, and parasitism rates were determined throughout the season. Predators were identified to family level but their impact was not quantified. P. atomaria adults were also examined as potential hosts for parasitic mites and nematodes. An undescribed species of Neopolycystus (Pteromalidae) was the major primary egg parasitoid species reared from egg batches, parasitising half of all egg batches collected. Three hyperparasitoid species (Baeoanusia albifunicle (Encyrtidae), Neblatticida sp. (Encyrtidae) and Aphaneromella sp. (Platygasteridae) were present, representing around one-quarter to one-third of all emergent wasps; this is the first host association record for Neopolycystus–B. albifunicle. In contrast to populations of P. atomaria from the Australian Capital Territory, primary larval parasitism was very low, around 1%, and attributable only to the tachinid flies Anagonia sp. and Paropsivora sp. However, the presence of the sit-and-wait larval hyperparasitoid, Perilampus sp. (Perilampidae) was high, emerging from around 17% of tachinid pupae, with planidia infesting a further 40% of unparasitised hosts. Three species of podapolipid mites parasitised sexually mature P. atomaria adults, while no nematodes were found in this study. Spiders were the most common predators and their abundance was positively correlated with P. atomaria adult and egg numbers. Although natural enemy species composition was identical between our two study sites, significant differences in abundance and frequency were found between sites