Eucalyptus Viminalis Research Articles

Protonophoric and uncoupling activity of royleanones from Salvia officinalis and euvimals from Eucalyptus viminalis.

The mechanism of action of quinones from the roots of Salvia officinalis L. (royleanones) and terpenoid phenolaldehydes from the leaves of Eucalyptus viminalis Labill. (euvimals) was studied. Royleanones and euvimals displayed marked protonophoric activity on artificial bilayer lipid membranes in vitro, and exerted an uncoupling action on oxidative phosphorylation in isolated rat liver mitochondria. The results suggest that biological membranes are the primary targets of royleanones and euvimals, and the protonophoric activity may contribute to the cytotoxicity and antimicrobial properties of these compounds.

Conversion of the Nitrate Nitrogen and Nitrogen Dioxide to Nitrous Oxides in Plants

AbstractTobacco and wheat are known to emit nitrous oxide (N2O). Provided that N2O is a greenhouse gas about 300 times worse than carbon dioxide in its potential for global warming, it is an intriguing and important subject, whether this activity is commonly present in other plants. In this study, 17 plant taxa that had been cultured aseptically were fed with15N‐labelled nitrate for one week (feeding period). The plant taxa were then transferred to a medium with non‐labelled nitrate in gas‐sealed pots and cultured for another week (emission period). The amount of labelled N2O emitted from the plants during the emission period was determined. This value reflects only a part of the capability of plants to convert nitrate to N2O, because the amount of N2O determined here does not correspond to the total N2O emission from plants, but to only an15N‐labelled N2O fraction emitted during the emission period from nitrate taken up into the plants during the feeding period. It was discovered that all of the 17 plant taxa analysed, except forEucalyptus viminalis,showed emission of15N2O. The emission ranged from 0.45 ± 0.20 ng N2O/g fresh weight (kenaf) to − 0.012 ± 0.12 ng N2O/g fresh weight (Eucalyptus viminalis). This activity of converting nitrate to N2O is obviously common in plants with some exceptions. There was more than a 58‐fold variation between the highest (Hibiscus cannabinus) and the second lowest (Nicotiana tabacum) capability to convert nitrate to N2O among the 17 plant taxa. The present result indicates that the potential of plants to convert nitrate to N2O highly varies among the plant species as in the case of the assimilation of nitrogen dioxide (N2O) where more than a 600‐fold variation was observed among 217 plant taxa. A negative correlation was obtained for N2O emission and NO2assimilation (r= 0.72).This is the first report where there was a competitive interaction between the assimilation and dissimilation activities in plants. It was also found that wild type and transgenic tobacco are able to convert NO2to N2O when they were fumigated with15N‐labelled NO2. However since the N2O emission values observed in this study were approximately three orders of magnitude smaller than those observed with wheat leaves, the evaluation of the environmental significance of the N2O emission by plants must await quantitative analysis using the present system to figure out the full N2O emission capability of plants.

Assimilation of Nitrogen Dioxide in Selected Plant Taxa

AbstractThe production of a novel “nitrogen‐dioxide‐philic plant” that can grow with NO2 as the sole nitrogen source was investigated as a possible solution to pollution. 217 plant taxa were screened for the assimilation of NO2, among them 50 wild herbaceous plants collected from roadsides, 60 cultivated herbaceous plants and 107 cultivated woody plants. It was discovered that the NO2‐derived reduced nitrogen [μg N/mg dry weight] differed by a factor of 657 between the highest (Eucalyptus viminalis, 6.57) and lowest (Tillandsia ionantha and T. caputmedusae, 0.01) level in the 217 taxa. The capability of plants to assimilate NO2 was also found to change in a family‐dependent manner. Compositae, Myrtaceae, Salicaceae and Solanaceae had taxa with high NO2 assimilation capability, while none of the Gramineae, Theaceae and Rosaceae plants examined showed high NO2 assimilation capability. The 217 taxa included two species of the Solanaceae family (tobacco and petunia), both of which showed a high NO2 assimilation and their reduced nitrogen derived from NO2 was the third and twenty‐sixth highest. This suggested that the Solanaceae family includes plants of high NO2 assimilation.Therefore, in this study eight taxa of the Solanaceae family and four taxa of other families were investigated for NO2 assimilation in the same manner as reported previously by the fumigation of plants with 15N‐labelled NO2 followed by the mass spectroscopic analysis based upon the reduced nitrogen derived from NO2. The eight taxa Solanaceae included tobacco (Nicotiana tabacum) and petunia (Petunia X hybrida), ground cherry (Physalis alkekengi var. franchetii), tomato (Lycopersicon esculentum), datura (Datura innoxia), potato vine (Solanum jasminoides), red pepper (Capsicum annuum) and green pepper (Capsicum annuum var. grossum SENDTN.). The four taxa included two ivy cultivars (Hedera helix “Pittsburgh” and Hedera helix “Wonder”), an evergreen creeper (Ficus thunbergii) and kenaf (Hibiscus cannabinus).Among the twelve taxa, kenaf, tobacco and ground cherry showed the highest, second and third highest values, respectively, of reduced nitrogen derived from NO2 in plants, which reflects the capability to assimilate NO2‐nitrogen. The quantitative significance of these findings is discussed in relation to the reduction of nitrogenous pollution by the atmospheric NO2 pollution.

Effects of substrates composed of biosolids on the production of Eucalyptus viminalis, Schinus terebinthifolius and Mimosa scabrella seedlings and on the nutritional status of Schinus terebinthifolius seedlings

Six substrates made up with heated and composted anaerobic biosolid were tested for the production of Eucalyptus viminalis, Schinus terebinthifolius and Mimosa scabrella forest seedlings in a nursery in Southern Brazil. The produced seedlings were statistically evaluated in relation to height, stem diameter, height/stem diameter ratio, aerial and root dry biomass, survival, and also for nutritional status on S. terebinthifolius seedlings. As a function of their high pH, heated biosolids turned out to be viable only in low composition percentages. Composted biosolids turned out to be sufficiently suitable in percentages between 30% and 60% of the substratum--whose Mn and Zn concentrations relate the nutrient contents in theseedlings -with use viability up to 100% in substratum composition.

New gall‐inducing species of ormocerine pteromalid (Hymenoptera: Pteromalidae: Ormocerinae) described from New Zealand

Abstract Nambouria xanthops Berry and Withers, a new species of ormocerine pteromalid reared from galls on Eucalyptus nicholii Maiden and Blakely, Eucalyptus glaucescens Maiden and Blakely, Eucalyptus cinerea F. Muell. ex Benth. and Eucalyptus viminalis Labill. (Myrtaceae), is described from New Zealand. Nambouria xanthops is presumed to be introduced accidentally from Australia. The placement of this new species in the genus Nambouria Boucek is discussed.

A barren part of the main?: the vegetation of Hunter Island, Fleurieu Group, Bass Strait

Hunter Island, visited over millennia by Aboriginal people and settled in the nineteenth century by sealers and later by a succession of grazing lessees, has preserved in its vegetation pattern the effects of a long history of firing and clearing. The vegetation also reflects the substrate and topographic features of the island with a major dichotomy between the heaths and scrub on the highly acid quartzites that underlie most of the island, and woodlands and grasslands on the highly alkaline sands that are rafted onto its western part. Eucalyptus viminalis occurs on alkaline sands on Hunter Island, in contrast to the absence of the species on calcareous coastal sands in the rest of its range in southeastern Australia. Heathlands make up 380/0 and scrub 37% of the island. Other vegetation types recorded are swamp forests, button grass moorland, exotic and native grasslands, Eucalyptus viminalis woodland, wetlands, mutton-bird rookery vegetation and lichen-fields. The flora has strong affinities with the northwestern coast of the Tasmanian mainland and a weaker affinity with Three Hummock Island, which is a granite island rather than a quartzite one. A Bassian floristic element occurs on the alkaline substrates; however, it is not as strong as that in the island flora of eastern Bass Strait. The flora and vegetation have components that are significant for nature conservation such as remnant Eucalyptus viminalisstands on the sands. The species ofconservation significance include rare and threatened species: Pterostylis cucullata, Calochilus herbaceous, Cyrtostylis robusta, Parietaria debilis, Ranunculus amphitrichus and Cotula vulgaris var. australasica.

Insect damage in Eucalyptus: A review of plantations in Chile

AbstractChile has more than 330 000 ha of eucalypt plantations, predominantly in the eighth to the tenth region (approximately 34 to 41°S). Eucalyptus globulus ssp. globulus is the principal eucalypt planted, but Eucalyptus nitens, Eucalyptus camaldulensis, Eucalyptus delegatensis and Eucalyptus viminalis are also grown. There are four main insect pests that have been detected attacking these eucalypts in Chile: the defoliator Gonipterus scutellatus, the bark borers Phoracantha semipunctata and Phoracantha recurva and the native wood borer Chilecomadia valdiviana. More recently, Thyrinteina arnobia and Ctenarytaina eucalypti have been detected. Gonipterus scutellatus and P. recurva have been discovered in Chile within the last 2 years and it is hoped they may still be eliminated using a combination of biological control and chemical control of local populations. Phoracantha recurva and P. semipunctata are not considered a problem because attack only occurs in areas of water deficit, away from current eucalypt plantations. Chilecomadia valdiviana can damage plantations of E. nitens but rarely attacks other eucalypts.◊Chilecomadia valdiviana may cause future problems through further host shifts. Thyrinteina arnobia has only been detected during quarantine surveillance in the port of Valparaiso. Ctenarytaina eucalypti, recently detected in August 1999, had an initial limited distribution in the first region. However, since then, this insect has expanded its distribution south up to the tenth region. None of the insects recorded on eucalypts in Chile to date currently presents a threat to the eucalypt industry. It is also essential that additional resources are made available for their continued monitoring and control, particularly given that the 44% of plantations are held by small to medium property owners that would otherwise be unable to control a serious outbreak because of economic restrictions.

The plasma membrane strength of the root-tip cells and root phenolic compounds are correiated with Al tolerance in several common woody plants

Ten species including one cultivar of common woody plants, i.e., Picea abies Karst. (Norway spruce), Gleditsia triacanthos L. (honey locust), Robinia pseudoacacia L. (black locust), Populus tremuloides Michx. (quaking aspen), Eucalyptus viminalis Labill. (eucalyptus), Cryptomeria japonica (Japanese cedar), Camellia sinensis L., cv. Yabukita (tea), Rhus succedanea L. (sumac), Pinus densiflora (Japanese red pine), and Pinus thunbergii Parl., cv. Sanshu (Sanshu black pine), and 2 species of marker crop plants, i.e., Oryza sativa L., cv. Sasanishiki (rice) and Hordeum vulgare L., cv. Manriki (barley), were cultured for 38 d at pH 4.3 in full nutrient solutions under three different stress conditions; 1) high AI, low P and low pH (combined stress), 2) low P and low pH, and 3) control. Soluble ionic Al and P concentrations in the media were maintained at almost 55 and 7 µM, respectively. P. thunbergii cv. Sanshu, C. sinensis, G. triacanthos, R. pseudoacacia, P. abies, and C. japonica were more tolerant to the combined stress than Oryza sativa known to be one of the most tolerant crop plants. Al tolerance obtained after the short-term stress for 24 h in CaCl2 solution at pH 4.7 was positively correlated with that obtained after the long-term combined stress, suggesting that a short-term screening technique can be used for the estimation of tolerance in acid soils. Under the combined stress conditions, low P stress was not expressed in any plant parts, Al stress was expressed primarily in roots and low pH stress was highly expressed in shoots. The roots of the AI-tolerant plants contained a significantly lower amount of Al with a higher K accumulation ratio. The plasma membrane strength (PMS), corresponding to the intactness of the PM permeability of root-tip cells during the re-elongation period without Al after temporary treatment with AI, was correlated with Al tolerance. Positive correlation between low pH tolerance and Al tolerance at pH 4.7 without H+ toxicity in both short-term experiments suggested that the PM of the root-tip cells was a common target for both stresses. Al tolerance of woody plants was positively correlated with the concentration of soluble phenolic compounds in roots irrespective of the treatment, but not with exuded phenolic compounds. In contrast to acidic conditions, in vitro binding affinity to Al ions at pH 7.0 was significantly higher at equimolar concentrations of quercetin, catechin, and chlorogenic acid but lower in the case of rutin, citric, oxalic, and malic acids. To our knowledge, this is the first report in which phenolic compounds in roots were quantitatively related to Al tolerance in woody plants. It was eventually suggested that AI-tolerant woody plants constitutively adopted a dual strategy involving a superior PMS and a higher amount of root phenolic compounds which can bind strongly with and detoxify Al ions in the cytoplasm.

A simple landscape‐scale test of a spatially explicit population model: patch occupancy in fragmented south‐eastern Australian forests

The results of a landscape‐scale test of ALEX, a widely used metapopulation model for Population Viability Analysis (PVA), are described. ALEX was used to predict patch occupancy by the laughing kookkaburra and the sacred kingfisher in patches of eucalypt forest in south‐eastern Australia. These predictions were compared to field surveys to determine the accuracy of the model. Predictions also were compared to a “naïve” null model assuming no fragmentation effects. The naïve null model significantly over‐predicted the number of eucalypt patches occupied by the sacred kingfisher, but the observed patch occupancy was not significantly different from that predicted using ALEX. ALEX produced a better fit to the field data than the naïve null model for the number of patches occupied by the laughing kookaburra. Nevertheless, ALEX still significantly over‐predicted the number of occupied patches, particularly remnants dominated by certain forest types – ribbon gum and narrow‐leaved peppermint. The predictions remained significantly different from observations, even when the habitat quality of these patches was reduced to zero. Changing the rate of dispersal improved overall predicted patch occupancy, but occupancy rates for the different forest types remained significantly different from the field observations. The lack of congruence between field data and model predictions could have arisen because the laughing kookaburra may move between an array of patches to access spatially separated food and nesting resources in response to fragmentation. Alternatively, inter‐specific competition may be heightened in a fragmented habitat. These types of responses to fragmentation are not incorporated as part of traditionally applied metapopulation models. Assessments of predictions from PVA models are rare but important because they can reveal the types of species for which forecasts are accurate and those for which they are not. This can assist the collection of additional empirical data to identify important factors affecting population dynamics.

Polyphenols from Eucalyptus consideniana and Eucalyptus viminalis

From the leaves of Eucalyptus consideniana and E. viminalis, known hydrolysable tannins, galloyl esters and ellagitannins, were isolated. Flavonol glycosides were also isolated from the leaves of E. consideniana. The spectral data of the dimeric ellagitannin, oenothein B (1), are reported.

Identifying performance indicators of the effects of forest management on ground-active arthropod biodiversity using hierarchical partitioning and partial canonical correspondence analysis

Biodiversity conservation in Australian native hardwood production forest is a central aim of sustainable forest management. However, the effects of timber extraction and fuel-reduction burning on the biodiversity of forest invertebrates are poorly understood. In this study, we use hierarchical partitioning and partial canonical correspondence analysis to examine the independent effects of these management practices on the richness and composition of ground-active ant and beetle assemblages. The study makes use of survey data from two types of production forest widespread in north-east New South Wales, New England Blackbutt ( Eucalyptus campanulata, R. Baker and H.G. Smith) and Messmate/Forest Ribbon Gum ( E. obliqua, L’Hér and E. nobilis, L. Johnson and K. Hill). Pitfall-trapped ants, and beetles from the families Carabidae, Scarabaeidae and Pselaphidae, were sorted to morphospecies and these survey data, together with habitat data, were used to explore two questions: (1) how much variation in the richness and composition of the arthropod assemblages at survey sites could be accounted for (independently) by logging and fire history? and (2) were other habitat variables better able to (independently) account for variation in arthropod richness and composition? Answers to these questions were used to identify potential performance indicators of the effects of forest management practices on ground-active arthropod biodiversity. Our analyses found that in New England Blackbutt forest sites, where selective logging was at low intensity, logging history explained little variation in arthropod richness or composition. By contrast, a strong influence of fire history and correlated habitat variables was evident. Fire history also explained significant variation in Messmate/Forest Ribbon Gum forest, but in this forest type, where logging intensity was higher, the influence of logging history was also apparent. This study finds support for the use of measures of ant richness, percent cover of sub-canopy (5–15 m above ground level) and ground-layer characteristics (litter depth, % cover of litter and bare ground) as performance indicators, because these attributes are relatively easy to measure, are affected by forest management, and are indicative of the effects of forest management on ground-active arthropod biodiversity.

Cavity sizes and types in Australian eucalypts from wet and dry forest types–a simple of rule of thumb for estimating size and number of cavities

We describe the relationships between the number, size and type of cavities in six species of eucalypt trees from southern New South Wales (south-eastern Australia) and tree diameter, tree height, tree species and other measures. The eucalypt species studied were:-Narrow-leaved Peppermint ( Eucalyptus radiata), Mountain Swamp Gum ( Eucalyptus camphora), Mountain Gum ( Eucalyptus dalrympleana), Red Stringybark ( Eucalyptus macrorhyncha), Ribbon Gum ( Eucalyptus viminalis), and, Broad-leaved Peppermint ( Eucalyptus dives). E. radiata and E. macrorhyncha supported almost twice the proportion of branch-end hollows than cavities assigned to other categories. Cavities in the main trunk were the predominant hollow class in E. viminalis and E. dalrympleana. Large diameter trees were characterised by more branch-end hollows, whereas main trunk cavities were typically the most prevalent cavity type in smaller diameter stems. We identified a simple, general rule that highlights the relationships between cavities and readily measured tree attributes. Our data show that, in general, both the number of cavities and cavity size were directly proportional to tree diameter, but inversely proportional to the square root of tree height. This proportionality changed between different tree species. E. dives and E. viminalis supported, on average, larger cavities than other species, whereas the cavities in E. macrorhyncha were smaller than the other taxa sampled. This simple general relationship may make it possible to make rapid crude estimates of cavity abundance across large areas of forest by measuring simple tree attributes such as tree diameter and tree height.

Effects on growth and comparison of root tissue colonization patterns of Eucalyptus viminalis by pathogenic and nonpathogenic strains of Fusarium oxysporum.

Soilborne pathogens, especially Fusarium oxysporum, are responsible for damping-off and root necrosis in Eucalyptus nurseries. New technologies are increasingly considering strategies for plant disease control other than chemical fungicides. Among these, natural fungal antagonists, which are colonizers of the root cortex, are potential biocontrol agents. An in vitro system was used: (1) to test the pathogenic effects of F. oxysporum strain Foeu1 which was recovered from a forest nursery soil; (2) to explore the potential of the nonpathogenic F. oxysporum strain Fo47, which is known for its efficiency in biological control, to suppress damping-off of Eucalyptus seedlings; (3) to compare the patterns of root colonization and host response to invasion by the two Fusarium strains inoculated separately in a time-course study. Root inoculation of E. viminalis with F. oxysporum strain Foeu1 caused damping-off in young seedlings in vitro, whilst disease symptoms were not visible in plants inoculated with F. oxysporum strain Fo47 or when both strains (Foeu1 + Fo47) were inoculated simultaneously. Each strain showed similarities in patterns of root tissue colonization, and in the processes of root penetration and initial colonization. Differential effects on root tissue were observed with fungal development within the cortex: ingress of strain Foeu1 was accompanied by severe host-cell alterations whilst no tissue damage occurred with development of strain Fo47.

Effects of variable-intensity logging and the influence of habitat variables on the distribution of the Greater Glider Petauroides volans in montane forest, southeastern New South Wales

Populations of arboreal marsupials were assessed in forests before and after logging at different levels of logging intensity to determine the sensitivity of these species to habitat disturbance. The logging treatments imposed were unlogged controls and two intensities of integrated logging for sawlogs and woodchips. The mean basal area of trees retained in logged blocks ranged from 83% to 35% of pre-logging levels. The objective of the study was to develop better methods for managing arboreal marsupials within the wood production forests of southeastern New South Wales. Seven species of arboreal marsupials were recorded during the study, but the Greater Glider Petauroides volans was the only species recorded in sufficient numbers for analysis (86% of all records). No significant differences were observed between the treatments in counts of the Greater Glider before and after logging. However, given the observed trend and an a priori expectation of a decline in numbers of this species following intensive logging, a one-tailed statistical test was applied which resulted in a significant difference at P = 0.08 for the contrast between the unlogged controls and the most intensively logged treatment. The existence of a threshold in logging intensity within the range of 21 % to 39% retention of tree basal area, below which numbers of the Greater Glider suffer a marked decline, was inferred on the basis of comparisons with the results of other studies. Factors other than logging were important in determining the distribution of the Greater Glider. Elevation, in particular, was a significant environmental variable, with Greater Gliders more likely to occur in forests above 845 m a.s.1. The presence and absence of particular tree species also influenced the distribution of the Greater Glider. Forests containing Manna Gum E. viminalis and Mountain Gum E. dalrympleana were highly preferred compared to forests with a high proportion of E. obliqua. The presence of E. cypellocarpa appeared to improve the quality of habitat for the Greater Glider in forests dominated by E. obliqua. This study has shown that Greater Glider populations can be maintained at or near pre-logging levels when at least 40% of the original tree basal area is retained thoughout logged areas and when the usual practice of retaining unlogged forest in riparian strips is applied.

Comparison of the susceptibility of two hardwood species, Mimosa scabrella Benth and Eucalyptus viminalis labill, to steam explosion and enzymatic hydrolysis

Steam explosion of two hardwood species was carried out with and without addition of sulfuric acid (H2SO4 0.5%, p/v) as a pretreatment catalyst. In general, wood chips of Eucalyptus viminalis Labill were shown to be more amenable to pretreatment than chips derived from bolds of Mimosa scabrella Benth (bracatinga). This was apparent from all pretreatment parameters tested including the overall recovery yields of pretreated fractions, carbohydrates (pentoses and hexoses) recovered as water-solubles, yield of dehydration by-products and lignin susceptibility to acid hydrolysis. There was no evidence for complete deacetylation of both wood species during pretreatment and lignin appeared to undergo extensive acid hydrolysis at higher pretreatment severities. Steam treatment at 205ºC for 5 min without addition of an acid catalyst was shown to be uncapable of removing the hemicellulose component from bracatinga chips, as determined by chemical analysis of the steam-treated water-insoluble fractions. Nearly 30% of the hemicellulose (xylan) found in bracatinga remained unhydrolysed after pretreatment, whereas more than 90% of this component could be removed from eucalypt chips under the same pretreatment conditions. Likewise, pretreatment of eucalypt chips resulted in a more extensive solubilization of glucans (cellulose) by acid hydrolysis. Addition of dilute H2SO4 as a pretreatment catalyst generally increased the recovery yield of fermentable sugars in the water-soluble fractions and this effect was more pronounced for the pretreatment of bracatinga chips. Steam-treated substrates produced from bracatinga were also less accessible to enzymatic hydrolysis than those produced from eucalypt chips, regardless of the use of an acid catalyst.

The effects of willow and eucalypt leaves on feeding preference and growth of some Australian aquatic macroinvertebrates

AbstractThe effect of leaf species (willow, Salix fragilis L., and white gum, Eucalyptus viminalis Labill.) and leaf state (senescent or green) on the feeding selectivity and growth rates of three species of macroinvertebrate Notalina sp. Mosely (Trichoptera: Leptoceridae), Koorrnonga sp. Campbell and Suter (Ephemeroptera: Leptophlebiidae) and Physastra gibbosa (Gould) (Mollusca: Planorbidae) were tested in the laboratory. All three species of macroinvertebrate selected green willow most strongly over the other leaf types (senescent willow, green eucalypt and senescent eucalypt). Growth rates of P. gibbosa and Notalina sp. were significantly greater on green willow than on the other leaf types. We were unable to measure the growth of Koorrnonga sp. Invertebrates had access to softer internal tissues of leaf material during preference trials, therefore we do not think that leaf structure was the main influence on selection between these materials. Green willow material may have been a better food source because of the noticeably thicker biofilm that it supported, and this material may also retain higher levels of nutrients than abscissed leaves. We speculate that willow leaves may provide a preferred source of food but will be available for less time than native eucalypt detritus.

Nest Site Selection and Breeding Success in Large Australian Honeyeaters: Are There Benefits from Being Different?

SummaryRed Wattlebird Anthochaera carunculata (n = 97) and Noisy Friarbird Philemon corniculatus (n = 229) nests were monitored over eight breeding seasons in eucalypt woodland in northern New South Wales. Red Wattlebirds nested in Eucalyptus viminalis and E. bridgesiana more frequently than expected from their relative abundance at the site. Noisy Friarbirds avoided stringybarks (E. caliginosa) but selected other eucalypts disproportionately. Nest success was similar in the two species (33% in Red Wattlebirds and 38% in Noisy Friarbirds), despite Friarbird nests being placed further horizontally from the base of the nest tree and being more conspicuous. The similar success may be because Noisy Friarbird nests are more inaccessible to mammalian predators and Red Wattlebird nests are less conspicuous to avian predators. In addition, Noisy Friarbirds tend to be more aggressive to avian predators than Red Wattlebirds, which may allow them to benefit from nests that have a good view of their surroundings. Neither species showed a relationship between nest success and nest height, horizontal distance from the base of the tree, nest tree height and trunk diameter or nest conspicuousness. Noisy Friarbird nests in E. blakelyi, although chosen most frequently, were less successful than those in other tree species and nests around mean height were less often successful than those higher or lower. The difference in nest locations between the species and diversity of nest sites chosen within each species could reduce the chance of a nest predator developing search images for specific nest locations. The suggestion that Noisy Friarbird nests in less common locations are more likely to be successful supports this hypothesis. Nests at the edge of the habitat patch and near tracks used by humans did not differ in their success rate from nests in the centre of the patch or away from tracks.

Characterization of residual lignin after SO(2)-catalyzed steam explosion and enzymatic hydrolysis of Eucalyptus viminalis wood chips.

The lignin component found in both water insoluble (WI) and water and alkali insoluble (WIA) fractions derived from SO(2)-impregnated steam-exploded eucalyptus chips (SEE) was isolated and characterized. Dioxane lignins with a sugar content lower than 2% (w/w) were obtained after each material was treated with commercial cellulases. The C9 formulas of both SEE-WI and SEE-WIA dioxane lignins were C(9)H(6.83)N(0.04)O(2.24)(OCH(3))(1.21)(OH(aro))(0.56)(OH(ali))(0. 77) and C(9)H(8.65)N(0.29)O(1.97)(OCH(3))(0.90)(OH(aro))(0. 46)(OH(ali))(1.02), respectively. The weight-average molecular weight (M(w)) of the SEE-WI lignin corresponded to 3.85 kDa, whereas the SEE-WIA lignin had an M(w) of 3.66 kDa for the same polydispersity of 2.4. The SEE-WIA lignin was shown to be more thermally stable than the SEE-WI lignin, requiring temperatures in the range of 520 degrees C for complete degradation. FTIR and (1)H NMR analyses of both untreated and peracetylated lignin fractions showed that (a) the alkali insoluble lignin contained a relatively higher degree of substitution in aromatic rings per C9 unit and that (b) alkaline extraction removed lignin fragments containing appreciable amounts of phenolic hydroxyl groups.

Secagem de madeira serrada de<i> Eucalyptus viminalis</i>.

Neste estudo foi avaliado um programa de secagem para madeira de Eucalyptus viminalis de 25,0 mm de espessura, de duas árvores previamente aneladas (antes da derrubada) e na confecção dos torretes) e posteriormente vaporizadas. O programa de secagem constou de três diferentes fases de vaporização, sendo uma inicial de duas horas, para acelerar o processo de secagem, uma vaporização intermediária de quatro horas, para recuperação do colapso e uma vaporização final de uma hora, para diminuir o gradiente de umidade e as tensões de secagem, todas realizadas a 100ºC. Os bons resultados obtidos com o programa de secagem aplicado permitiu um aproveitamento de 72% da madeira (livre de defeitos). Estes resultados positivos podem ser atribuídos à aplicação de um programa de secagem gradual, às diferentes vaporizações a que a madeira foi submetida, como também ao fato de ter-se aplicado a técnica de anelamento e vaporização.

More than a 600‐fold variation in nitrogen dioxide assimilation among 217 plant taxa

Assimilation of nitrogen dioxide in response to fumigation with 15N‐labelled nitrogen dioxide was studied in 217 plant taxa. The taxa included 50 wild herbaceous plants collected from roadsides (42 genera, 15 families), 60 cultivated herbaceous plants (55 genera, 30 families) and 107 cultivated woody plants (74 genera, 45 families). Two parameters, the ‘NO2‐N content’, or NO2‐derived reduced nitrogen content in fumigated plant leaves (mg N g–1 dry weight), and the ‘NO2‐utilization index’, or percentage of the NO2‐derived reduced nitrogen in the total reduced nitrogen, were determined. The NO2‐N content differed 657‐fold between the highest (Eucalyptus viminalis; 6·57) and lowest (Tillandsia ionantha and T. caput‐medusae; 0·01) values in the 217 taxa; 62‐fold in a family (Theaceae) and 26‐fold in a species (Solidago altissima). Nine species had NO2‐utilization indices greater than 10%, of which Magnolia kobus, Eucalyptus viminalis, Populus nigra, Nicotiana tabacum and Erechtites hieracifolia had NO2‐N contents > 4·9. These plants can be considered ‘NO2‐philic’ because in them NO2‐nitrogen has an important function(s). The Compositae and Myrtaceae had high values for both parameters, whereas the monocots and gymnosperms had low ones. These findings suggest that the metabolic pathway of NO2‐nitrogen differs among plant species. The information presented here will be useful for creating a novel vegetation technology to reduce the atmospheric concentration of nitrogen dioxide.