Showing papers on "Bark published in 2006"

Exogenous application of methyl jasmonate elicits defenses in Norway spruce (Picea abies) and reduces host colonization by the bark beetle Ips typographus.

Abstract: The terpenoid and phenolic constituents of conifers have been implicated in protecting trees from infestation by bark beetles and phytopathogenic fungi, but it has been difficult to prove these defensive roles under natural conditions. We used methyl jasmonate, a well-known inducer of plant defense responses, to manipulate the biochemistry and anatomy of mature Picea abies (Norway spruce) trees and to test their resistance to attack by Ips typographus (the spruce bark beetle). Bark sections of P. abies treated with methyl jasmonate had significantly less I. typographus colonization than bark sections in the controls and exhibited shorter parental galleries and fewer eggs had been deposited. The numbers of beetles that emerged and mean dry weight per beetle were also significantly lower in methyl jasmonate-treated bark. In addition, fewer beetles were attracted to conspecifics tunneling in methyl jasmonate-treated bark. Stem sections of P. abies treated with methyl jasmonate had an increased number of traumatic resin ducts and a higher concentration of terpenes than untreated sections, whereas the concentration of soluble phenolics did not differ between treatments. The increased amount of terpenoid resin present in methyl jasmonate-treated bark could be directly responsible for the observed decrease in I. typographus colonization and reproduction.

Antibacterial Effect of Edible Plant Extract on Escherichia coli 0157:H7

Abstract: Sixteen preparation of the ethanol and aqueous extracts of four edible plants, Entada africana (bark),Terminalia avicennoides (bark),Mitragyna stipulosa (bark) Lannae acida (stem bark) were screened for their inhibitory effects on ten strains of E coli 0157:H7 (EHEC) using the agar diffusion method. It was shown that ethanol extracts of Entanda africana inhibited all the ten strains used, some extracts showed variable antibacterial activities while some others could not cause any inhibition. The minimum inhibitory concentration (MIC) of the potent extracts ranged from 1.56mg/ml to 50.00mg/ml while the minimum bacteriocidal concentration (MBC) was between 6.25mg/ml to 25.00mg/ml. Pytochemical screening of the extracts revealed that all contained saponin. Some showed presence of tannins and glycosides while alkaloid was not detected in all samples.

Identification of an antimicrobial entity from the cyanobacterium Fischerella sp. isolated from bark of Azadirachta indica (Neem) tree

Abstract: The active principle in a methanolic extract of the laboratory-grown cyanobacterium, Fischerella sp. isolated from Neem (Azadirachta indica) tree bark was active against Mycobacterium tuberculosis, Enterobacter aerogenes, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhi, Escherichia coli as well as three multi-drug resistant E. coli strains in in vitro assays. Based on MS, UV, IR 1H NMR analyses the active principle is proposed to be hapalindole T having the empirical formula C21H23N2ClSO and a molecular weight of 386 with the melting point range 179–182 °C. The estimated production of Hapalindole T from the cyanobacterium is 1.25 mg g−1 lyophilized biomass. It is suggested that cyanobacteria colonizing specialized niches such as tree bark could be an antibacterial drug resource.

Probability of Bark Stripping Damage by Red Deer (Cervus elaphus) in Austria

Abstract: Bark stripping by red deer (Cervus elaphus) causes considerable damage to Austrian forests, however, the incidence of bark stripping was never examined from large scale survey data. In this manuscript we present a logistic regression model for bark stripping damage (static model) and a model for recent (5-year period) bark stripping damage to previously undamaged trees (dynamic model) developed from Austrian National Forest Inventory data. Both models showed bark stripping damage to be most frequent in core red deer habitat areas and less frequent in less suitable habitat. Damage was concentrated at elevations of 400–1200 m and in alluvial forests (only static model). Norway spruce (Picea abies), European ash (Fraxinus excelsior), Sweet chestnut (Castanea sativa) and Sorbus spp. had 11–12 times more injuries than all the other species. Red deer preferred the smallest trees with a breast height diameter of 5 cm for bark stripping and damage probability decreased rapidly for trees with a breast height diameter greater than 25 cm. Our static model showed a maximum of bark stripping damage in stands with a mean height of 20 m. In the dynamic model the probability for bark stripping damage decreased with decreasing mean height. Also, in the static model the probability for bark stripping damage increased with increasing spruce proportion and with increasing stand density whereas in the dynamic model the proportion of previous bark stripping damage was a good predictor. Goodness of fit and discrimination of both models were good. In combination with forest growth models, the bark stripping models can be used to predict the risk of damage associated with different forest and habitat management options.

Phenolic Glycosides With Antioxidant Activity From the Stem Bark of Populus Davidiana

Abstract: Phytochemical study on the EtOAc-soluble fraction of the stem bark of Populus davidiana resulted in the isolation of 10 phenolic glycosides (1−10), which were identified on the basis of physicochemical and spectroscopic analyses. Among these, three new compounds, populosides A−C (1−3), were determined to be 2-coumaroylmethyl-4-hydroxyphenyl-β-d-glucopyranoside, 2-coumaroylmethylphenyl-β-d-glucopyranoside, and 2-feruoylmethylphenyl-β-d-glucopyranoside, respectively. Compounds 1−10 were tested for their radical scavenging activity against an azo radical, ABTS•+. Of these, populosides A−C (1−3), populoside (4), grandidentatin (8), salireposide (9), and coumaroyl-β-d-glucoside (10) exhibited antioxidant activity in this assay.

Antifeedants in the Feces of the Pine Weevil Hylobius abietis : Identification and Biological Activity

Abstract: Egg-laying females of the pine weevil, Hylobius abietis (L.), regularly deposit feces adjacent to each egg. Egg cavities are gnawed in the bark of roots of recently dead conifer trees. After egg deposition, the cavity is sealed by feces and a plug of bark fragments. Root bark containing egg cavities with feces is avoided as food by pine weevils, which indicates the presence of natural antifeedants. Here we present the first results of the isolation and chemical analyses of antifeedant compounds in the feces of H. abietis. In feeding bioassays, methanol extracts of the feces revealed strong antifeedant properties. Methanol extracts were fractionated by medium-pressure liquid chromatography and the antifeedant effects were mainly found in the fractions of highest polarity. Volatile compounds in the active fractions were identified by gas chromatography-mass spectrometry (GC-MS) and the nonvolatile compounds were characterized by pyrolysis-GC-MS. Based on mass spectra, a number of compounds with various chemical structures were selected to be tested for their antifeedant properties. Antifeedant effects were found among compounds apparently originating from lignin: e.g., a methylanisol, guaiacol, veratrol, dihydroxybenzenes, and dihydroconiferyl alcohol. A weak effect by fatty acid derivatives was found. The types of naturally occurring antifeedant compounds identified in this study may become useful for the protection of planted conifer seedlings against damage by H. abietis.

Antiplasmodial flavonoids from Erythrina sacleuxii.

Abstract: The acetone extracts of the root bark and stem bark of Erythrina sacleuxii showed antiplasmodial activities against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum. Chromatographic separation of the acetone extract of the root bark afforded a new isoflavone, 7-hydroxy-4'-methoxy-3'-prenylisoflavone (trivial name 5-deoxy-3'-prenylbiochanin A) along with known isoflavonoids as the antiplasmodial principles. Flavonoids and isoflavonoids isolated from the stem bark of E. sacleuxii were also tested and showed antiplasmodial activities. The structures were determined on the basis of spectroscopic evidence.

Estimation of U.S. Bark Generation and Implications for Horticultural Industries

Abstract: The historical, current, and projected supply of bark was evaluated. Since the 1980s more than 95 percent of the U.S. bark supply has been utilized in some way. Industrial fuel consumes the largest share of the market for bark, absorbing about 83 percent of softwood bark and 66 to 71 percent of hardwood bark. Current market share of bark for horticulture use (categorized in the miscellaneous group), is about 15 percent of softwood bark supply and about 30 percent of hardwood bark supply. In recent years, domestic timber harvest has been relatively stable or has slightly decreased. During the same time period, there has been an increasing demand for bark as an energy resource. Based on historical data, linear models were fitted between U.S. timber harvest and bark generation at the regional level. With those fitted models, projected bark generation was estimated based on the timber harvest data of the fifth Renewable Resources Planning Act (RPA) timber assessment. It is estimated that only a minor...

In Vivo Antioxidant Activity of Procyanidin-Rich Extracts from Grape Seed and Pine (Pinus Maritima) Bark in Rats

Abstract: Background: In vitro evidence exists for the potential antioxidant benefits of procyanidin-rich extracts, but in vivo studies are scarce. We have evaluated the effects of selected procyanidin-rich ...

Interactions between calcium and copper or cadmium in Norway spruce

Abstract: The accumulation of calcium (Ca), copper (Cu) and cadmium (Cd) in roots and stem of Norway spruce (Picea abies [L.] Karst) was examined. Two-year-old Norway spruce seedlings were treated with elevated concentrations of Ca, Cd or Cu, or as combinations of Ca with Cu or Cd in nutrient solutions for three months. The stem was divided into bark, wood formed during the treatment period (new wood), and wood formed before the treatment period (old wood). The accumulation of the metals in stem and roots increased with addition of the respective metal into nutrient solution. Addition of Cu decreased the accumulation of Ca in roots and wood, and Ca addition decreased the accumulation of Cu in the new wood. By adding Ca in combination with Cu the accumulation of Cu in the stem was decreased even more by Ca and the negative effect of Cu on the Ca content in the stem was diminished. Addition of Cd decreased the accumulation of Ca in wood, especially the old wood, and Ca addition decreased the accumulation of Cd in roots, bark and new wood. By adding Ca in combination with Cd the Ca content was reduced in the bark, instead of in the old wood.

Characterization of the photosynthetic apparatus in cortical bark chlorenchyma of Scots pine

Abstract: Winter-induced inhibition of photosynthesis in Scots pine (Pinus sylvestris L.) needles is accompanied by a 65% reduction of the maximum photochemical efficiency of photosystem II (PSII), measured as F v/F m, but relatively stable photosystem I (PSI) activity. In contrast, the photochemical efficiency of PSII in bark chlorenchyma of Scots pine twigs was shown to be well preserved, while PSI capacity was severely decreased. Low-temperature (77 K) chlorophyll fluorescence measurements also revealed lower relative fluorescence intensity emitted from PSI in bark chlorenchyma compared to needles regardless of the growing season. Nondenaturating SDS-PAGE analysis of the chlorophyll–protein complexes also revealed much lower abundance of LHCI and the CPI band related to light harvesting and the core complex of PSI, respectively, in bark chlorenchyma. These changes were associated with a 38% reduction in the total amount of chlorophyll in the bark chlorenchyma relative to winter needles, but the Chl a/b ratio and carotenoid composition were similar in the two tissues. As distinct from winter pine needles exhibiting ATP/ADP ratio of 11.3, the total adenylate content in winter bark chlorenchyma was 2.5-fold higher and the estimated ATP/ADP ratio was 20.7. The photochemical efficiency of PSII in needles attached to the twig recovered significantly faster (28–30 h) then in detached needles. Fluorescence quenching analysis revealed a high reduction state of Q A and the PQ-pool in the green bark tissue. The role of bark chlorenchyma and its photochemical performance during the recovery of photosynthesis from winter stress in Scots pine is discussed.

Antioxidant potential of six pine species.

Abstract: The aim of the study was to evaluate the antioxidant efficacy of extracts obtained from six Pinus species (P. pinea, P. brutia, P. radiata, P. halepensis, P. attenuata, P. nigra) growing in natural forests in Southern Greece. Specimens of fresh, dry needles and pine bark were extracted and fractionated with a variety of organic solvents and the efficient concentration and their radical scavenging activity was evaluated by the Co(II)/EDTA induced luminol plateau chemiluminescence assay.

Monoterpene chemodiversity of ponderosa pine in relation to herbivory and bark beetle colonization

Abstract: Ponderosa pine, Pinus ponderosa Laws. (Pinaceae), forests in Arizona have suffered from a nine-year period of drought and bark beetle, Ips lecontei Swaine (Coleoptera: Scolytidae), outbreaks. Abiotic and biotic stress in ponderosa pine results in the induced synthesis of certain monoterpenes that may in turn affect bark beetle behavior and survival. In this study, we investigate whether induced monoterpene production could result in a different monoterpene composition that remains stored in the needles or the trunk resin of the tree. Needle and resin samples in addition to trunk cores were collected from ponderosa pines at three locations in Arizona. Ungulate browsing induced a significant increase in limonene (P=0.010) and in chemodiversity (P=0.009), a measure of the evenness of distribution among the monoterpenes present in needles. We compared the level of ‘stress’ of the trees by measuring the thickness of annual rings in living trees and those that were killed by bark beetles. Where drought occurred, the spacing of annual rings from the last 10 years of trees killed by bark beetles was significantly smaller (P=0.020) compared to living trees. There was no difference in the monoterpene composition between the core sections of closest spacing of annual rings (stressed years) compared to the sections of widest spacing, which indicates that monoterpenes are distributed evenly throughout the extended resin system. In the area where the degree of drought was less overall, none of the individual monoterpenes present in the resin was related to bark beetle killed trees. However, about half the living pines had resin in which one of the major monoterpenes (α-pinene, Δ3-carene, and limonene) was absent, and these trees had a lower monoterpene chemodiversity compared to trees killed by bark beetles. Trees with these three major monoterpenes, corresponding to the average relative proportion in living pines at that location, may sustain higher selection and colonization by bark beetles.

Anthropogenic fire and bark thickness in coastal and island pine populations from Alta and Baja California

Abstract: Aim Native American fire use influenced bark thickness of coastal and island Monterey pine (Pinus radiata D. Don) and bishop pine (Pinus muricata D. Don) populations. Methods Basal bark thickness and d.b.h. were measured in two common-garden pine plantations that included all five native Monterey pine populations and nine of 10 native bishop pine populations. One-factor analysis of covariance was used to determine if significant differences in bark thickness existed between island and coastal populations. Results Bark thickness was measured on 228 Monterey and 42 bishop pines. Bark thickness in coastal and island Monterey pine populations was significantly different. Bark thickness in coastal and island bishop pine populations was not significantly different. Main conclusions Basal bark was thick in populations where there was a history of Native American burning. Basal bark was thin in two island populations where Native Americans have been absent or distant from the pine populations. While other influences no doubt affect the evolution of lower-bole bark thickness, it appears that frequent anthropogenic fires may be a powerful selection force.

Comparação de equações volumétricas ajustadas com dados de cubagem e análise de tronco.

Abstract: This work aimed at comparing volume estimates with bark, obtained with equations originated from data of the stem measurements with bark and stem analysis without bark, respectively. The base of information for the development of this study was obtained in forest of Pinus taeda L. in the municipal district of Ponte Alta do Norte, Santa Catarina, being composed by two hundred and forty trees measured with bark in different ages, which were selected aleatorily and distributed by diameter class. Another source of data was obtained with the stem analysis without bark of thirty sample trees, distributed among averages and dominant. Mathematical models were tested for each source of data, in order to select the one of better adjustment and precision, with base in the selection criterion of the Score Pondered Value of the Statistical Parameters (VP). The result of VP revealed the equation of Schumacher-Hall as the most appropriated one in the estimate of the volume for the respective sources of data. The comparison between the estimates of volume of the adjusted models starting from data of the stem measurements with bark and of the stem analysis without bark was accomplished with the test Qui-square, which demonstrated that there area no significant differences to be significant difference among the them allowing to affirm that it is possible to obtain the volume with bark starting from an equation generated with volume data without bark, obtained through the stem analysis.

Volatile constituents from flowers, leaves, bark and wood of Prunus mahaleb L.

Abstract: Volatile constituents from air-dried flowers, leaves, stem-bark and wood of Prunus mahaleb L. (Rosaceae) were isolated by steam-distillation and analysed using GC and GC–MS; 130 components were identified. Aliphatic hydrocarbons, alcohols, carbonyls, fatty acids, terpenes, C13-norisoprenoids and phenylpropane derivatives were detected. Coumarin was identified as the main component of the bark volatiles (34.1%). Hexadecanoic acid was the main component in the wood (46.0%), and was also present in the leaves (17.8%) and bark (9.3%). n-Alkanes, heneicosane (22.1%) and octacosane (13.0%) were identified as the main components in the flowers, while eicosane was detected in the wood (12.9%). Phytol was identified in the leaves (5.1%). Dodecanoic, tetradecanoic and linoleic acids were present in all samples among the major components. The contents of volatile compounds were 340.0 mg/kg (flowers), 64.6 mg/kg (leaves), 41.0 mg/kg (bark) and 6.6 mg/kg (wood). Copyright © 2005 John Wiley & Sons, Ltd.

Secondary Metabolites from the Wood Bark of Durio zibethinus and Durio kutejensis

Abstract: Phytochemical exploration of a wood bark extract from Durio zibethinus afforded two new triterpenoids, namely, methyl 27-O-trans-caffeoylcylicodiscate (1) and methyl 27-O-cis-caffeoylcylicodiscate (2), a new phenolic, 1,2-diarylpropane-3- ol (3), and seven known compounds, fraxidin, eucryphin, boehmenan, threo-carolignan E, (-)-(3R, 4S)-4-hydroxymellein, methyl protocatechuate, and (+)-(R)-de-O-methyllasiodiplodin (4). In addition, chemical analysis of a wood bark extract from Durio kutejensis yielded the new triterpenes 3 beta-O-trans-caffeoyl-2R-hydroxyolean-12-en-28-oic acid (5) and 3 beta-trans-caffeoyl-2R-hydroxytaraxest-12-en-28-oic acid (6) together with four known compounds, maslinic acid, arjunolic acid, 2,6-dimethoxy-p-benzoquinone, and fraxidin. The structures of all compounds were determined on the basis of spectroscopic data.