Showing papers on "Bark published in 2015"
TL;DR: It is hypothesize that fire is a key factor selecting for a thick bark, and thus, at the global scale, a significant proportion of the variability in bark thickness is explained by the variability of fire regimes.
Abstract: Summary 1. Bark is a vital and very visible part of woody plants, yet only recently has bark characteristics started to be considered as key traits structuring communities and biomes. Bark thickness is very variable among woody plants, and I hypothesize that fire is a key factor selecting for a thick bark, and thus, at the global scale, a significant proportion of the variability in bark thickness is explained by the variability in fire regimes. Previous research has focused on the importance of bark thickness mainly in surface-fire regimes; here I generalize this idea and present a conceptual framework to explain how the different drivers that affect fire intensity have shaped bark thickness, in conjunction with other plant traits. 2. I first review methods used to study bark thickness and then provide examples of bark thickness patterns from a wide range of ecosystems subject to different fire regimes (understorey fires, grass-fuelled surface fires, grass-fuelled crown fires and infrequent fires). 3. There are some fire regimes that select for thick barks, while some only in the base of the trunk (e.g. understorey fires), others select for a thick bark on the whole plant (e.g. grassfuelled crown fires). There are also fire regimes in which allocating resources to a thick bark is not adaptive (e.g. woody-fulled crown fires). 4. Fire regime can explain a large proportion of the variability of bark thickness at the global scale, and thus, this trait varies across ecosystems in a predictable manner; however, the current paucity of data limits a fully accurate analysis.
241 citations
TL;DR: In this article, the authors used colorimetric methods to determine the total phenolic, total flavonoids, and various in vitro antioxidant activities (DPPH, ABTS and FRAP) of methanolic extract.
238 citations
TL;DR: Results indicate that an important quantity of bioactive compounds can be extracted from spruce wood bark by ultrasound assisted extraction technology.
178 citations
TL;DR: The most promising species for a bark tannin extraction was found to be larch, while the least encouraging results were detected in pine, and a better knowledge of the interaction between the various extracted compounds is deemed an important matter for investigation.
93 citations
TL;DR: In this paper, a state-of-the-art review is compiled carrying out a comprehensive literature search on the biosorption of heavy metals in solution onto different tree species, including a characterization of bark structure and chemistry.
Abstract: Tree bark is among the widely available and low-cost sorbents for metal adsorption in aqueous environments. A state-of-the-art review is compiled carrying out a comprehensive literature search on the biosorption of heavy metals in solution onto different bark species, including a characterization of bark structure and chemistry. The results indicate that biosorption has been gaining importance for bark valorization purposes. Promising heavy metal uptake values have already been attained using different bark species. These values are comparable to those obtained with commercial activated carbons. Bark has a cost advantage over activated carbon and can be used without any pretreatment. Thus, bark offers a green alternative to remove heavy metals from industrial waters. A brief survey of the chemical composition and structure of different bark species is presented. Suggestions are made to improve screening of bark species for specific heavy metal ions sorption.
90 citations
TL;DR: In this paper, a study was conducted to determine the phytochemical content, antibacterial activity, and antioxidant activity of leaves, bark and pods of Acacia nilotica and the results indicated that all parts of the plant, but especially leaves, were effective in inhibiting the growth of antibiotic resistant strains of Escherichia coli and Salmonella species.
81 citations
TL;DR: Variation in wood carbon (C) and nitrogen (N) concentrations in 17 temperate tree species across five woody tissue types was examined, suggesting that intraspecific variation in C across tissue types is less important than intersp...
Abstract: Quantifying variation in the wood chemical traits of trees is critical for parameterizing forest biogeochemical budgets and models. Available data on wood chemical traits are based largely on samples taken from main stems; few studies have evaluated how wood chemical traits vary among major woody tissue types. We examined variation in wood carbon (C) and nitrogen (N) concentrations in 17 temperate tree species across five woody tissue types: sapwood, heartwood, small branches, coarse roots, and bark; analyses were corrected for losses of volatile C. Both C and N varied significantly among tissue types, but differences were driven mainly by high C and N in bark, a pattern observed for nearly all species. Among nonbark tissue types, bivariate correlations among sapwood, heartwood, small branches, and coarse roots were highly significant and positive for wood C (r = 0.88–0.98) and N (r = 0.66–0.95) concentrations. We suggest that intraspecific variation in C across tissue types is less important than intersp...
59 citations
TL;DR: Belowground N transfer from Acacia to Eucalyptus trees in the field during the first few days after labeling may provide a significant amount of the nitrogen requirements of trees close to N-fixing trees in mixed forests.
Abstract: The short-term belowground transfer of nitrogen from nitrogen-fixing trees to companion trees has never been studied in the field A 15N pulse-labeling study was conducted in a mixed plantation of Acacia mangium and Eucalyptus grandis at the peak of leaf area, 26 months after planting 15N–NO3− was injected into the stem of one big Acacia tree in three plots 15N was traced over 2 months in the labeled Acacia tree as well as in neighboring Eucalyptus trees For both species, young leaves were sampled, as well as fine roots and the rhizosphere at a distance of 075 m and 225 m from the labeled tree The 15N atom% was also determined in the wood, bark, branches and total foliage of the 3 labeled Acacia trees and 9 Eucalyptus trees, 60 days after labeling Most of the leaves, fine roots and rhizosphere samples of both species were 15N enriched from 5 days after labeling The δ15N values were higher at a distance of 075 m than at 225 m in Acacia roots, but were similar at both distances in Eucalyptus roots and the rhizospheres The wood and bark of Eucalyptus trees sampled at a distance of 62 m from the labeled Acacia trees were 15N enriched This shows belowground N transfer from Acacia to Eucalyptus trees in the field during the first few days after labeling This facilitation process may provide a significant amount of the nitrogen requirements of trees close to N-fixing trees in mixed forests
58 citations
01 Jan 2015
54 citations
TL;DR: The results indicate that relative bark thickness is likely the primary bark trait affecting fire-induced topkill and influencing the distribution of species along the pocosin-to-savanna gradient.
Abstract: The probability of stem survival after fire is strongly influenced by energy allocation to bark because bark thickness affects heat transfer during fire. Greater relative investment in inner bark versus outer bark should also enhance survival because of greater moisture content of inner bark. We measured stem diameter, bark thickness, and habitat preference of five species typical of long-leaf pine savannas, and six species characteristic of adjacent wetlands (pocosins), and calculated relative bark thickness, the inner bark proportion, radial growth, and bark accumulation of each species. We hypothesized that savanna species have thicker bark and greater relative investment in inner bark than pocosin species, because fires occur more frequently in savannas than pocosins. As hypothesized, savanna species have relatively thicker bark than pocosin species. Relative bark thickness and the rate of bark accumulation were correlated with the mean location of a species along the pocosin-to-savanna gradient. However, the inner bark proportion did not differ between savanna and pocosin species. Our results indicate that relative bark thickness is likely the primary bark trait affecting fire-induced topkill and influencing the distribution of species along the pocosin-to-savanna gradient.
52 citations
TL;DR: The results suggest that pine mortality can be attributed to an intense drought stress level that caused xylem cavitation, and indicate that hydraulic failure and carbon starvation are likely interrelated, which makes separating both mechanisms very difficult.
Abstract: Key message
Pine mortality was related to water stress, which caused xylem cavitation. Hydraulic failure and carbon starvation are likely interrelated, and bark beetles attacks did not seem to be directly involved.
TL;DR: The outerbark of Pseudotsuga menziesii was chemically analyzed after selective fractioning into different particles sizes as mentioned in this paper, and the results showed that the fine fraction was enriched in extractives and polysaccharides as well as in inorganics, and impoverished in suberin.
TL;DR: A series of amine-sulfonate functionalized ionic liquids (ASF-ILs) were synthesized, characterized, and evaluated for the dissolution of model biopolymers.
TL;DR: Sapwood, heartwood and bark of 70-year-old teak trees from an unmanaged stand in East Timor were characterized by pyrolysis (Py-GC-MS/FID) as discussed by the authors.
Abstract: Sapwood, heartwood and bark of 70-year-old teak trees from an unmanaged stand in East Timor were characterized by pyrolysis (Py–GC–MS/FID). Sapwood and heartwood from teak presented a high lignin content (35.4 and 37.3 % of extractive-free wood) and similar composition. Teak wood is characterized by a GS type of lignin (56.0 % of G-units, 42.2 % of S-units and 1.8 % of H-units in extractive-free wood), with an S/G ratio of 0.8. The major lignin-derived compounds were 4-vinylsyringol (6.6 %), coniferyl alcohol (trans) (4.5 %), coniferaldehyde (2.0 %), 4-vinylguaiacol (1.6 %) and 4-methylguaiacol (1.6 %). Extractive-free teak bark presented 28.0 % of lignin, characterized by a GS type, with 53.3 % G-units, 42.1 % S-units and 4.6 % H-units, with S/G ratio of 0.8. The high lignin content and a composition with predominance of G-units may contribute to the durability and mechanical resistance of teakwood.
TL;DR: This study determined the ability of four major fungal symbionts of the spruce bark beetle Ips typographus to produce beetle aggregation pheromones and provides new insight into the possible ecological roles of fungal Symbionts in bark beetle systems and may deepen the understanding of species interactions and coevolution in these important biological systems.
Abstract: Tree-killing bark beetles depend on aggregation pheromones to mass-attack their host trees and overwhelm their resistance. The beetles are always associated with phytopathogenic ophiostomatoid fungi that probably assist in breaking down tree resistance, but little is known about if or how much these fungal symbionts contribute to the beetles’ aggregation behavior. In this study, we determined the ability of four major fungal symbionts of the spruce bark beetle Ips typographus to produce beetle aggregation pheromones. The fungi were incubated on Norway spruce Picea abies bark, malt agar, or malt agar amended with 0.5 % 13C glucose. Volatiles present in the headspace of each fungus were analyzed for 7 days after incubation using a SPME autosampler coupled to a GC/MS. Two Grosmannia species (G. penicillata and G. europhioides) produced large amounts of 2-methyl-3-buten-2-ol (MB), the major component in the beetles’ aggregation pheromone blend, when growing on spruce bark or malt agar. Grosmannia europhioides also incorporated 13C glucose into MB, demonstrating that the fungi can synthesize MB de novo using glucose as a carbon source. This is the first clear evidence that fungal symbionts of bark beetles can produce components in the aggregation pheromone blend of their beetle vectors. This provides new insight into the possible ecological roles of fungal symbionts in bark beetle systems and may deepen our understanding of species interactions and coevolution in these important biological systems.
Journal Article•
TL;DR: In this paper, the GC-MS analysis of the ethanol extract of P. alatum has been carried out and 13 phytochemical constituents from leaf and eleven phytochemicals from bark have been identified by comparing the chromatogram, peak value of the unknown compound with entries in NIST database.
Abstract: Pleiospermium alatum (Wall. ex Wight & Arn.) Swingle is one of the medicinally important plants belonging to the family Rutaceae, commonly known as Malai Naarthai. The present study deals with the GC-MS analysis of ethanol extract of the above mentioned plant. Thirteen phytochemical constituents from leaf and eleven phytochemical constituents from bark have been identified by comparing the chromatogram, peak value of the unknown compound with entries in NIST database. The prevalent compounds viz., Squalene (13.57%), Lupeol (8.81%), 9,12-Octadecadienoic acid (Z,Z)- (8.36%), n-Hexadecanoic acid (6.11%), ethyl ester, Phytol (5.13%) and Hexadecanoic acid (0.93%) are found in leaf. In bark the prevalent phytochemical constituents are 9,12-Octadecadienoic acid (Z,Z)- (18.81%), All-trans-Squalene (17.55%), n-Hexadecanoic acid (12.61%),Oleic acid (5.88%) and 9-Hexadecanoic acid (2.15%) in bark. These results indicate the ethanol extract of leaf and stem bark of P. alatum possess potent antioxidant, anti-inflammatory, anticancer, antitumour, antiarthritic, cancer preventive, antibacterial effects so that it can be recommended as a plant of phytopharmaceutical importance.
TL;DR: It is found that S. paradoxus can grow well on sterile medium made from oak bark, but that its growth is strongly suppressed when the other members of the community are present, and that its success depends on the much more abundant microbial species surrounding it.
Abstract: The natural history of the model yeast Saccharomyces cerevisiae is poorly understood and confounded by domestication. In nature, S. cerevisiae and its undomesticated relative S. paradoxus are usually found on the bark of oak trees, a habitat very different from wine or other human fermentations. It is unclear whether the oak trees are really the primary habitat for wild yeast, or whether this apparent association is due to biased sampling. We use culturing and high-throughput environmental sequencing to show that S. paradoxus is a very rare member of the oak bark microbial community. We find that S. paradoxus can grow well on sterile medium made from oak bark, but that its growth is strongly suppressed when the other members of the community are present. We purified a set of twelve common fungal and bacterial species from the oak bark community and tested how each affected the growth of S. paradoxus in direct competition on oak bark medium at summer and winter temperatures, identifying both positive and negative interactions. One Pseudomonas species produces a diffusible toxin that suppresses S. paradoxus as effectively as either the whole set of twelve species together or the complete community present in nonsterilized oak medium. Conversely, one of the twelve species, Mucilaginibacter sp., had the opposite effect and promoted S. paradoxus growth at low temperatures. We conclude that, in its natural oak tree habitat, S. paradoxus is a rare species whose success depends on the much more abundant microbial species surrounding it.
TL;DR: Despite generally higher RE content in young shoots, the overall removal of RE was higher in older wood classes due to higher biomass yield, and longer rotations seem to be more effective when phytoextraction strategy is considered.
Abstract: Fast-growing clones of Salix and Populus have been studied for remediation of soils contaminated by risk elements (RE) using short-rotation coppice plantations. Our aim was to assess biomass yield and distributions of elements in wood and bark of highly productive willow (S1—[Salix schwerinii × Salix viminalis] × S. viminalis, S2—Salix × smithiana clone S-218) and poplar (P1–Populus maximowiczii × Populus nigra, P2—P. nigra) clones with respect to aging. The field experiment was established in April 2008 on moderately Cd-, Pb- and Zn- contaminated soil. Shoots were harvested after four seasons (February 2012) and separated into annual classes of wood and bark. All tested clones grew on contaminated soils, with highest biomass production and lowest mortality exhibited by P1 and S2. Concentrations of elements, with exception of Ca and Pb, decreased with age and were higher in bark than in wood. The Salix clones were characterised by higher removal of Cd, Mn and Zn compared to the Populus clones. Despite generally higher RE content in young shoots, partly due to lower wood/bark ratios and higher RE concentrations in bark, the overall removal of RE was higher in older wood classes due to higher biomass yield. Thus, longer rotations seem to be more effective when phytoextraction strategy is considered. Of the four selected clones, S1 exhibited the best removal of Cd and Zn and is a good candidate for phytoextraction.
TL;DR: Compared bark accumulation in five co-occurring hardwood species within a longleaf pine ecosystem in the mountains of northeastern Alabama, USA, it was found that, while average wood diameter did not differ across species, significant differences occurred in the ratio of bark to wood.
Abstract: Fire affects numerous aspects of plant growth and anatomy, particularly in those species adapted to persist in fire-prone environments. A key aspect of tree survival is rapid accumulation of protective bark within fire return intervals. We compared bark accumulation in five co-occurring hardwood species within a longleaf pine (Pinus palustris) ecosystem in the mountains of northeastern Alabama, USA. Sampled species included blackjack oak (Quercus marilandica), sand hickory (Carya pallida), common persimmon (Diospyros virginiana), rock chestnut oak (Quercus montana), and red maple (Acer rubrum). Using bark thickness and inside bark diameter measurements taken at 20-cm intervals along the main stem of saplings (average age 4–5 years) we found that, while average wood diameter did not differ across species, significant differences occurred in the ratio of bark to wood. Bark comprised over half (bark:wood = 0.55) of the basal diameter of blackjack oak, which was 3×, 4×, and 6× greater than the bark:wood ratio...
TL;DR: It seems that the ecology of twig bark can be generalized to main stem bark, but not for functions depending on the amount of bark, such as protection, storage, or photosynthesis.
Abstract: Although produced by meristems that are continuous along the stem length, marked differences in bark morphology and in microenvironment would suggest that main stem and twig bark might differ ecologically. Here, we examined: (1) how closely associated main stem and twig bark traits were, (2) how these associations varied across sites, and (3) used these associations to infer functional and ecological differences between twig and main stem bark. We measured density, water content, photosynthesis presence/absence, total, outer, inner, and relative thicknesses of main stem and twig bark from 85 species of angiosperms from six sites of contrasting precipitation, temperature, and fire regimes. Density and water content did not differ between main stems and twigs across species and sites. Species with thicker twig bark had disproportionately thicker main stem bark in most sites, but the slope and degree of association varied. Disproportionately thicker main stem bark for a given twig bark thickness in most fire-prone sites suggested stem protection near the ground. The savanna had the opposite trend, suggesting that selection also favors twig protection in these fire-prone habitats. A weak main stem-twig bark thickness association was observed in non fire-prone sites. The near-ubiquity of photosynthesis in twigs highlighted its likely ecological importance; variation in this activity was predicted by outer bark thickness in main stems. It seems that the ecology of twig bark can be generalized to main stem bark, but not for functions depending on the amount of bark, such as protection, storage, or photosynthesis.
TL;DR: In this article, the phytochemical contents of the leaves, stem bark and root of Jatropha curcas (J.curcas) in four solvent extracts and their proximate and mineral compositions were analyzed.
Abstract: Objective To analyse the phytochemical contents of leaf, stem bark and root of Jatropha curcas (J. curcas) in four solvent extracts and their proximate and mineral compositions. Methods Standard analytical procedures were used for the determination of phytochemicals, proximate and mineral compositions of the leaf, stem bark and root extracts of J. curcas. Results Results of the analysis showed the presence of polyphenols, flavonoids, alkaloids, cardiac glycosides, coumarins, saponins, terpenoids, steroids, triterpenoid saponins, carotenoids, phlobatannins and tannins in the leaf, stem bark and root of all the solvent extracts. Flavonoids were present in the highest amount in the ethyl acetate extracts of the leaf (7.35% ± 0.02%), stem bark (4.12% ± 0.01%) and root (3.35% ± 0.02%) followed by polyphenols in the methanol extracts of leaf (4.62% ± 0.02%), stem bark (2.77% ± 0.05%) and root (2.49% ± 0.02%). Poly-acetylated compounds were absent in all the solvent extracts of the leaf, stem bark and root. However, some anti-nutritional agents such as oxalates, phytates and cyanates were present in all the solvent extracts of the leaf, stem bark and root except the ethyl acetate. Phytates were high in the aqueous solvent of the leaf (6.12% ± 0.00%) but low in the stem bark (1.00% ± 0.05%) and root (0.89% ± 0.03%). Proximate composition showed appreciable amounts of total carbohydrate (36.33% ± 0.72%), crude protein (26.00% ± 0.47%) and reducing sugars (5.87% ± 0.14%) in the leaf, while crude fat was more in the stem bark (16.70% ± 0.30%). There was corresponding substantial energy in the leaf [(1514.77 ± 20.87) kJ/100 g] and stem bark [(907.00 ± 8.52) kJ/100 g]. Moisture and ash contents of the leaf, stem bark and root were within acceptable limits for the use in drugs formulation. The mineral composition showed substantial amounts of important elements such as Fe, Ca, Na, Mg and Zn. Others were P, K and Se. Conclusions The outcome of this study suggests that the leaf, stem bark and root of J. curcas have very good medicinal potentials, meet the standard requirements for drug formulation and serve as good sources of energy and nutrients except for the presence of some anti-nutritional elements predominant in the leaf.
TL;DR: Results suggest that K. coriacea, a Brazilian plant, provide initial evidence of a new and alternative source of substances with medicinal interest, as well as showing the strongest antimicrobial activity against the anaerobic bacteria Prevotella nigrescens.
Abstract: Many essential oils (EOs) of different plant species possess interesting antimicrobial effects on buccal microorganisms and cytotoxic properties. EOs of Kielmeyera coriacea Mart. & Zucc. were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The EO from leaves is rich in sesquiterpenes hydrocarbons and oxygenated sesquiterpenes. The three major compounds identified were germacrene-D (24.2%), (E)-caryophyllene (15.5%), and bicyclogermacrene (11.6%). The inner bark EO is composed mainly of sesquiterpenes hydrocarbons and the major components are alpha-copaene (14.9%) and alpha-(E)-bergamotene (13.0%). The outer bark EO is composed mainly of oxygenated sesquiterpenes and long-chain alkanes, and the major components are alpha-eudesmol (4.2%) and nonacosane (5.8%). The wood EO is mainly composed of long-chain alkanes and fatty acids, and the major components are nonacosane (9.7%) and palmitic acid (16.2%). The inner bark EO showed the strongest antimicrobial activity against the anaerobic bacteria Prevotella nigrescens (minimum inhibitory concentration-MIC of 50 µg mL−1). The outer bark and wood EOs showed MICs of 100 µg mL−1 for all aerobic microorganisms tested. The EOs presented low toxicity to Vero cells. These results suggest that K. coriacea, a Brazilian plant, provide initial evidence of a new and alternative source of substances with medicinal interest.
TL;DR: In this paper, a study of spruce tannins reactivity for rigid foam formulations was conducted, where rigid and homo- geneous foams were produced from purified tannics containing at least 80% of polyflavonoid condensed tannin.
TL;DR: The results confirmed the feasibility of U. tomentosa as a suitable raw material for obtaining phenolic- and alkaloid-rich extracts of potential interest.
Abstract: The phenolic composition of extracts from Uncaria tomentosa L. from different regions of Costa Rica was studied using advanced analytical techniques such as UPLC/TQ-ESI-MS and (13)C-NMR. Samples from leaves, stems, bark and wood (n = 22) were subjected to extraction to obtain phenolic and alkaloid extracts, separately. Comparatively, higher values of total phenolic content were observed for leaves, stems and bark (225-494 gallic acid equivalents/g) than for wood extracts (40-167 gallic acid equivalents/g). A total of 32 non-flavonoid and flavonoid compounds were identified in the phenolic extracts: hydroxybenzoic acids (benzoic, salicylic, 4-hydroxybenzoic, prochatechuic, gallic, syringic and vanillic acids), hydroxycinnamic acids (p-coumaric, caffeic, ferulic and isoferulic acids), flavan-3-ols monomers [(+)-catechin and (-)-epicatechin)], procyanidin dimers (B1, B2, B3, B4, B5, B7 and two other of unknown structure) and trimers (C1, T2 and one of unknown structure), flavalignans (four unknown structures pertaining to the cinchonain family) and propelargonidin dimers (four unknown structures, reported for the first time in U. tomentosa). Additionally, alkaloid extracts obtained from the plant residue after phenolic extraction exhibited a content of tetracyclic and pentacyclic alkaloids ranging between 95 and 275 mg/100 g of dry material for bark extracts, and between 30 and 704 mg/100 g for leaves extracts. In addition, a minor alkaloid was isolated and characterized, namely 18,19-dehydrocorynoxinoic acid. Our results confirmed the feasibility of U. tomentosa as a suitable raw material for obtaining phenolic- and alkaloid-rich extracts of potential interest.
TL;DR: The aim of this study is to investigate some biological effects of Cola nitida's bark after phytochemical screening and extractions, which revealed the presence of various potent phytochemicals.
Abstract: Kola nut is chewed in many West African cultures and is used ceremonially. The aim of this study is to investigate some biological effects of Cola nitida's bark after phytochemical screening. The bark was collected, dried, and then powdered for the phytochemical screening and extractions. Ethanol and ethyl acetate extracts of C. nitida were used in this study. The antibacterial activity was tested on ten reference strains and 28 meat isolated Staphylococcus strains by disc diffusion method. The antifungal activity of three fungal strains was determined on the Potato-Dextrose Agar medium mixed with the appropriate extract. The antioxidant activity was determined by DPPH and ABTS methods. Our data revealed the presence of various potent phytochemicals. For the reference and meat isolated strains, the inhibitory diameter zone was from 17.5 ± 0.7 mm (C. albicans) to 9.5 ± 0.7 mm (P. vulgaris). The MIC ranged from 0.312 mg/mL to 5.000 mg/mL and the MBC from 0.625 mg/mL to >20 mg/mL. The highest antifungal activity was observed with F. verticillioides and the lowest one with P. citrinum. The two extracts have an excellent reducing free radical activity. The killing effect of A. salina larvae was perceptible at 1.04 mg/mL. The purified extracts of Cola nitida's bark can be used to hold meat products and also like phytomedicine.
TL;DR: From the in vitro experiment, the methanol extracts of Callistemon viminalis bark were effective against the growth of F. culmorum and A. tenuissima, as well as some contamination by other microorganisms, except for the wood treated with the meethanol extract of M. pomifera bark.
Abstract: Natural compounds from certain timber trees are highly valued and recommended to protect wood and wood products against mold fungi This study highlighted the use of some natural extracts and Paraloid B-72 against the growth of two mold fungi, namely Alternaria tenuissima and Fusarium culmorum From the in vitro experiment, the methanol extracts of Callistemon viminalis bark were effective against the growth of F culmorum, as were Magnolia grandiflora leaves against A tenuissima Environmental scanning electron microscopy (ESEM) and electron dispersive X-ray spectroscopy (EDX) analysis of treated Acacia saligna wood with the two fungi and Paraloid B-72 demonstrated the clear hyphal growth of F culmorum and A tenuissima and changes in elemental chemical composition After three months, no fungal growth on the wood surface treated with the methanol extract of M pomifera bark was found After three months of treating wood with Paraloid B-72 at 5% and 10%, the mold growth was visible Almost all of the wood treated with methanol extracts showed growth of the A tenuissima hypha, as well as some contamination by other microorganisms, except for the wood treated with the methanol extract of M pomifera bark
TL;DR: It was significantly more difficult to hydrolyse spruce bark to monomeric sugars than wood chips, and Bark had an adverse effect on the whole bioconversion process due to its lower enzymatic hydrolyzability.
Abstract: Bark and bark-containing forest residues have the potential for utilization as raw material for lignocellulosic ethanol production due to their abundance and low cost. However, the different physical properties and chemical composition of bark compared to the conventionally used wood chips may influence the spruce-to-ethanol bioconversion process. This study assesses the impact of bark on the overall bioconversion in two process configurations, separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF), utilizing steam-pretreated spruce bark and wood mixtures. Mixtures of different proportions of spruce bark and wood chips were subjected to SO2-catalyzed steam pretreatment at 210°C for five minutes, which has been shown to be effective for the pretreatment of spruce wood chips. The final ethanol concentration was the highest without bark and decreased significantly with increasing proportions of bark in both process configurations. However, this decrease cannot be attributed solely to the lower availability of the carbohydrates in mixtures containing bark, as the ethanol yield also decreased, from 85 to 59% in SSF and from 84 to 51% in SHF, as the mass fraction of bark was increased from 0 to 100%. The results show that it was significantly more difficult to hydrolyse spruce bark to monomeric sugars than wood chips. Bark had an adverse effect on the whole bioconversion process due to its lower enzymatic hydrolyzability. On the other hand, bark inclusion had no detrimental effect on the fermentability of steam-pretreated spruce wood and bark mixtures. It was also observed that lower amounts of inhibitory degradation products were formed during the steam pretreatment of spruce bark than during the steam pretreatment of wood chips.
TL;DR: In this paper, the anatomical characteristics of Eucalyptus grandis wood and the transition age between the juvenile and mature woods were evaluated by fiber length measurement from the pith to the bark.
Abstract: The present study is aimed at evaluating the anatomical characteristics of Eucalyptus grandis wood and the transition age between the juvenile and mature woods. Four trees of 23-year-old E. grandis were used. The juvenile, transition and mature wood zones were found by fiber length measurement from the pith to the bark. Samples were taken from juvenile wood, transition wood and mature wood and the anatomical properties of the wood were determined. The results showed that: (1) the fiber length, cell wall thickness, slenderness ratio, cell wall fraction and tangential vessel diameter increase from pith to bark; (2) fibers, axial parenchyma, ray parenchyma cells and vessels are equally distributed from pith to bark; (3) the transition zone between juvenile and mature wood occurs between the age of 8 and 13 years.
TL;DR: A large number of ambrosia beetles, bark beetles, and other weevils are attracted to stressed walnut trees in Indiana and Missouri, and several of these species have the potential to introduce walnut canker pathogens during colonization.
Abstract: Thousand cankers disease (TCD) is a new disease of black walnut (Juglans nigra L.) in the eastern United States. The disease is caused by the interaction of the aggressive bark beetle Pityophthorus juglandis Blackman and the canker-forming fungus, Geosmithia morbida M. Kolarik, E. Freeland, C. Utley & Tisserat, carried by the beetle. Other insects also colonize TCD-symptomatic trees and may also carry pathogens. A trap tree survey was conducted in Indiana and Missouri to characterize the assemblage of ambrosia beetles, bark beetles, and other weevils attracted to the main stems and crowns of stressed black walnut. More than 100 trees were girdled and treated with glyphosate (Riverdale Razor Pro, Burr Ridge, Illinois) at 27 locations. Nearly 17,000 insects were collected from logs harvested from girdled walnut trees. These insects represented 15 ambrosia beetle, four bark beetle, and seven other weevil species. The most abundant species included Xyleborinus saxeseni Ratzburg, Xylosandrus crassiusculus Motschulsky, Xylosandrus germanus Blandford, Xyleborus affinis Eichhoff, and Stenomimus pallidus Boheman. These species differed in their association with the stems or crowns of stressed trees. Multiple species of insects were collected from individual trees and likely colonized tissues near each other. At least three of the abundant species found (S. pallidus, X. crassiusculus, and X. germanus) are known to carry propagules of canker-causing fungi of black walnut. In summary, a large number of ambrosia beetles, bark beetles, and other weevils are attracted to stressed walnut trees in Indiana and Missouri. Several of these species have the potential to introduce walnut canker pathogens during colonization.