Chemical composition changes in eucalyptus and pinus woods submitted to heat treatment

This study investigated the influence of heat treatment on the chemical composition of Eucalyptus saligna and Pinus caribaea var. hondurensis woods to understand its role in wood processing. E. saligna and P. caribaea var. hondurensis woods were treated in a laboratorial electric furnace at 120, 140, 160 and 180 degrees C to induce their heat treatment. The chemical composition of the resulting products and those from original wood were determined by gas chromatography. Eucalyptus and Pinus showed a significant reduction in arabinose, manose, galactose and xylose contents when submitted to increasing temperatures. No significant alteration in glucose content was observed. Lignin content, however, increased during the heat process. There was a significant reduction in extractive content for Eucalyptus. On the other hand, a slight increase in extractive content has been determined for the Pinus wood. and that only for the highest temperature. These different behaviors can be explained by differences in chemical constituents between softwoods and hardwoods. The results obtained in this study provide important information for future research and utilization of thermally modified wood. (c) 2008 Elsevier Ltd. All rights reserved.

Effects of moist chilling and solid matrix priming on germination of loblolly pine (Pinus taeda L.) seeds

Loblolly pine ( Pinus taeda L.) seeds from sources with a mild climate under maritime influence (North Carolina) required shorter moist chilling to achieve maximum germination vigor than seeds from sources with a harsher continental climate (Oklahoma). Solid matrix priming (SMP) for 6 d achieved as much as 60 d of moist chilling to improve rapidity, synchrony and completeness of germination for three of the four families studied. SMP after moist chilling increased the rapidity, synchrony and completeness of germination. The benefit of SMP was greatest for non-stratified seeds and the benefit decreased with length of moist chilling. In general, delaying planting for one week after SMP had minor effects on germination when seeds were kept in the SMP matrix at 4 degreesC. Delayed planting after SMP can increase germination rapidity and synchrony of seeds that have received long moist chilling and reduce the benefit of SMP in non-moist-chilled seeds.

Airborne Pinus pollen in the atmosphere of Brisbane, Australia and relationships with meteorological parameters

Relationships between weather parameters andairborne pollen loads of Pinus inBrisbane, Australia have been investigated overthe five-year period, June 1994–May 1999.Pinus pollen accounts for 4.5% of the annualairborne pollen load in Brisbane where thePinus season is confined to the winter months,July–early September. During the samplingperiod loads of 11–>100 grains m3 wererecorded on 24 days and 1–10 grains m3 on204 days. The onset and peak dates wereconsistent across each season, whereas the enddates varied. The onset of the Pinuspollen season coincided with the coolestaverage monthly temperatures (< 22°C),lowest rainfall (< 7mm), and four weeks afterdaily minimum temperatures fell to 5–9°Cin late autumn. Correlations obtained betweendaily airborne Pinus pollen counts andtemperature/rainfall parameters show thatdensities of airborne Pinus pollen arenegatively correlated with maximum temperature(p < 0.0001), minimum temperature (p < 0.0001)and rainfall (p < 0.05) during the mainpollination period. The mean duration of eachpollen season was 52 days; longer seasons wereshown to be directly related to lower averageseasonal maximum temperatures (r2 = 0.85,p = 0.025). These results signify that maximumand minimum temperatures are the majorparameters that influence the onset andduration of the Pinus pollen season inthe environs of Brisbane. Respiratory allergyis an important health issue in Brisbane,Australia, but it remains unknown whether ornot airborne Pinus pollen is acontributing factor.

Expression analysis of four Pinus radiata male cone promoters in the heterologous host Arabidopsis

Four male cone-specific promoters were isolated from the genome of Pinus radiata D. Don, fused to the beta-glucuronidase (GUS) reporter gene and analysed in the heterologous host Arabidopsis thaliana (L.) Heynh. The temporal and spatial activities of the promoters PrCHS1, PrLTP2, PrMC2 and PrMALE1 during seven anther developmental stages are described in detail. The two promoters PrMC2 and PrMALE1 confer an identical GUS expression pattern on Arabidopsis anthers. DNA sequence analysis of the PrMC2 and PrMALE1 promoters revealed an 88% sequence identity over 276 bp and divergence further upstream (

Fitorremediação de solo contaminado com picloram por capim-pé-de-galinha-gigante (Eleusine coracana)

O longo efeito residual do herbicida picloram no solo aumenta o risco de lixiviação e de fitotoxicidade em culturas sucedâneas; sua presença no solo pode ser abreviada com o uso da fitorremediação. O objetivo deste trabalho foi avaliar a influência da densidade populacional de capim-pé-de-galinha-gigante (Eleusine coracana) sobre a fitorremediação de solo contaminado com o herbicida picloram. O experimento foi realizado em casa de vegetação localizada no município de Rio Verde-GO, no período de setembro de 2006 a fevereiro de 2007. Os tratamentos foram compostos pela combinação entre quatro densidades populacionais da espécie vegetal Eleusine coracana (capim-pé-de-galinha-gigante) (0, 7, 14 e 21 plantas por vaso, correspondendo a 0, 172, 344 e 516 plantas m-2, respectivamente) e três doses do picloram (0, 80 e 160 g ha-1 - aplicadas diretamente nos vasos, simulando níveis de contaminação do solo). Após o cultivo da espécie vegetal fitorremediadora no substrato por 100 dias, efetuou-se, no próprio vaso, a semeadura da soja (Glycine max L.), espécie utilizada como bioindicadora da presença do picloram. A espécie Eleusine coracana mostrou ter capacidade de remediar solos contaminados com o herbicida picloram. A partir de 172 plantas m-2, aumentos na densidade populacional da espécie fitorremediadora não proporcionaram redução de carryover do herbicida picloram sobre a cultura da soja semeada em sucessão.

Characterization of the volatile fraction emitted by phloems of four pinus species by solid-phase microextraction and gas chromatography–mass spectrometry

Pine forests constitute some of the most important renewable resources supplying timber, paper and chemical industries, among other functions. Characterization of the volatiles emitted by different Pinus species has proven to be an important tool to decode the process of host tree selection by herbivore insects, some of which cause serious economic damage to pines. Variations in the relative composition of the bouquet of semiochemicals are responsible for the outcome of different biological processes, such as mate finding, egg-laying site recognition and host selection. The volatiles present in phloem samples of four pine species, P. halepensis, P. sylvestris, P. pinaster and P. pinea, were identified and characterized with the aim of finding possible host-plant attractants for native pests, such as the bark beetle Tomicus piniperda. The volatile compounds emitted by phloem samples of pines were extracted by headspace solid-phase micro extraction, using a 2 cm 50/30 mm divinylbenzene/carboxen/polydimethylsiloxane table flex solid-phase microextraction fiber and its contents analyzed by high-resolution gas chromatography, using flame ionization and a non polar and chiral column phases. The components of the volatile fraction emitted by the phloem samples were identified by mass spectrometry using time-of-flight and quadrupole mass analyzers. The estimated relative composition was used to perform a discriminant analysis among pine species, by means of cluster and principal component analysis. It can be concluded that it is possible to discriminate pine species based on the monoterpenes emissions of phloem samples.

Insignificant impact of prescribed fire on surface soil in a Pinus pinaster plantation, northern Portugal

Following a prescribed fire in a Pinus pinaster forest site located in the north-west Portugal, monitoring of any changes in selected soil characteristics and soil hydrology was undertaken to assess the effects of burning on the following: pH, electrical conductivity, water content, organic carbon and porosity. Thirty plots were established on a regular grid. At each sample plot before and after the fire, samples were collected (disturbed samples from depths of 0-1cm and 1-5cm; undisturbed core samples from 0-5cm). The results indicate that there was no measurable impact on the properties of the soil following this carefully conducted prescribed fire. The fire only affected the litter layer, as intended. Confirmation of this minimal impact on the soil was provided by regrowth of grasses and herbs already occurring two months after the fire. The implication is, therefore, that provided this wildfire-risk reduction strategy is carried out under existing strict guidelines, any impact on soil quality will be minimal.

Effects of prescribed fire on surface soil in a Pinus pinaster plantation, northern Portugal

In order to decrease the risk of severe wildfire, prescribed fire has recently been adopted in Portugal and elsewhere in the Mediterranean as a major tool for reducing the fuel load instead of manual or mechanical removal of vegetation. There has been some research into its impact on soils in shrublands and grasslands, but to date little research has been conducted in forested areas in the region. As a result, the impact of prescribed fire on the physico-chemical soil characteristics of forest soils has been assumed to be minimal, but this has not been demonstrated. In this study, we present the results of a monitoring campaign of a detailed pre- and post-prescribed fire assessment of soil properties in a long-unburnt P. pinaster plantation, NW Portugal. The soil characteristics examined were pH, total porosity, bulk density, moisture content, organic matter content and litter/ash quantity. The results show that there was no significant impact on the measured soil properties, the only effect being confined to minor changes in the upper 1 cm of soil. We conclude that provided the fire is carried out according to strict guidelines in P. pinaster forest, a minimal impact on soil properties can be expected.

Characterization of Pinus spp. needles by gas chromatography and mass spectrometry: Application to plant-insect interactions

Dissertação apresentada para obtenção do Grau de Doutor em Ciências do Ambiente pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecn

Effects of prescribed fire on surface soil in a Pinus pinaster plantation, northern Portugal

In order to decrease the risk of severe wildfire, prescribed fire has recently been adopted in Portugal and elsewhere in the Mediterranean as a major tool for reducing the fuel load instead of manual or mechanical removal of vegetation. There has been some research into its impact on soils in shrublands and grasslands, but to date little research has been conducted in forested areas in the region. As a result, the impact of prescribed fire on the physico-chemical soil characteristics of forest soils has been assumed to be minimal, but this has not been demonstrated. In this study, we present the results of a monitoring campaign of a detailed pre- and post-prescribed fire assessment of soil properties in a long-unburnt P. pinaster plantation, NW Portugal. The soil characteristics examined were pH, total porosity, bulk density, moisture content, organic matter content and litter/ash quantity. The results show that there was no significant impact on the measured soil properties, the only effect being confined to minor changes in the upper 1 cm of soil. We conclude that provided the fire is carried out according to strict guidelines in P. pinaster forest, a minimal impact on soil properties can be expected.

Laparoscopia em Tumor Quístico Gigante do Ovário na Adolescência. A Propósito de um Caso Clínico

A eficácia e segurança da cirurgia laparoscópica na resolução dos tumores quísticos benignos do ovário tem sido demonstrada por inúmeros estudos. As dimensões do tumor quístico do ovário foi, até há algum tempo atrás, factor limitante na opção cirúrgica: se superior a 10 cm a laparotomia era a indicação. Actualmente, a cirurgia laparoscópica está associada a muitas vantagens: redução da hemorragia operatória, menos complicações pós-operatórias, menor tempo de hospitalização, mais rápida recuperação e melhor resultado estético. Os autores descrevem o caso de uma adolescente de 15 anos de idade, com um tumor quístico gigante do ovário (mais de 30 cm), ocupando todos os quadrantes do abdómen, e que foi tratado laparoscopicamente com sucesso após punção/drenagem aspirativa sob controle ecográfico. Conclusão: Com uma criteriosa selecção dos doentes, a laparoscopia cirúrgica é segura em doentes com quistos benignos gigantes do ovário.