Outer Layer Of Bark Research Articles

Evaluation of Antioxidative Mechanisms In Vitro and Triterpenes Composition of Extracts from Silver Birch (Betula pendula Roth) and Black Birch (Betula obscura Kotula) Barks by FT-IR and HPLC-PDA.

Silver birch, Betula pendula Roth, is one of the most common trees in Europe. Due to its content of many biologically active substances, it has long been used in medicine and cosmetics, unlike the rare black birch, Betula obscura Kotula. The aim of the study was therefore to compare the antioxidant properties of extracts from the inner and outer bark layers of both birch trees towards the L929 line treated with acetaldehyde. Based on the lactate dehydrogenase test and the MTT test, 10 and 25% concentrations of extracts were selected for the antioxidant evaluation. All extracts at tested concentrations reduced the production of hydrogen peroxide, superoxide anion radical, and 25% extract decreased malonic aldehyde formation in acetaldehyde-treated cells. The chemical composition of bark extracts was accessed by IR and HPLC-PDA methods and surprisingly, revealed a high content of betulin and lupeol in the inner bark extract of B. obscura. Furthermore, IR analysis revealed differences in the chemical composition of the outer bark between black and silver birch extracts, indicating that black birch may be a valuable source of numerous biologically active substances. Further experiments are required to evaluate their potential against neuroinflammation, cancer, viral infections, as well as their usefulness in cosmetology.

FOSSILIZATION OF THE EOCENE “MONKEYHAIR” LATICIFER TREE FROM GEISELTAL, GERMANY: A DEEPER UNDERSTANDING USING MICRO-CT AND PYROLYSIS GC/MS

ABSTRACTAlthough the fibrous plant material called Affenhaar from the middle Eocene lignites of Geiseltal in Germany has been repeatedly studied for over 172 years, modern imaging and chemical analyses have enabled a deeper understanding of its chemical composition and preservation within the parent plant. Known in English as “monkeyhair,” the fibrous material represents a very rare case of fossil laticifers, the latex-bearing ducts of plants. Here we use high-resolution X-ray microcomputed tomography (micro-CT) for the first time to elucidate the anatomy of tissues and their differential degradation within the monkeyhair tree. Even in large, fairly intact stem axes, the center cylinder of secondary xylem inside the trunks or branches is completely absent, presumably due to diagenetic degradation. Nevertheless, there is a moderately well-preserved outer layer of bark and mats of excellently preserved laticifers in the extraxylary zone beneath the bark. Previous chemical analyses revealed that the latex in these laticifers was dominated by natural rubber (cis-1,4-polyisoprene), but also included various triterpenoids. These fossil laticifers also contained large amounts of organic sulfur, suggesting the rubber may have been naturally vulcanized. Pyrolysis GC/MS is also applied to the fossil laticifers for the first time to identify the organic sulfur constituents of this ancient latex. The chemical analysis yields 12 major sulfur compounds, mostly thiophenes, consistent with vulcanized rubber. The vulcanization of these laticifers most likely occurred during early diagenesis, before the degradation of the wood, at low temperatures, and may have been facilitated with other compounds that served as accelerators, activators, and fillers.

Fate of Antioxidative Compounds within Bark during Storage: A Case of Norway Spruce Logs.

Softwood bark is an important by-product of forest industry. Currently, bark is under-utilized and mainly directed for energy production, although it can be extracted with hot water to obtain compounds for value-added use. In Norway spruce (Picea abies [L.] Karst.) bark, condensed tannins and stilbene glycosides are among the compounds that comprise majority of the antioxidative extractives. For developing feasible production chain for softwood bark extractives, knowledge on raw material quality is critical. This study examined the fate of spruce bark tannins and stilbenes during storage treatment with two seasonal replications (i.e., during winter and summer). In the experiment, mature logs were harvested and stored outside. During six-month-storage periods, samples were periodically collected for chemical analysis from both inner and outer bark layers. Additionally, bark extractives were analyzed for antioxidative activities by FRAP, ORAC, and H2O2 scavenging assays. According to the results, stilbenes rapidly degraded during storage, whereas tannins were more stable: only 5–7% of the original stilbene amount and ca. 30–50% of the original amount of condensed tannins were found after 24-week-storage. Summer conditions led to the faster modification of bark chemistry than winter conditions. Changes in antioxidative activity were less pronounced than those of analyzed chemical compounds, indicating that the derivatives of the compounds contribute to the antioxidative activity. The results of the assays showed that, on average, ca. 27% of the original antioxidative capacity remained 24 weeks after the onset of the storage treatment, while a large variation (2–95% of the original capacity remaining) was found between assays, seasons, and bark layers. Inner bark preserved its activities longer than outer bark, and intact bark attached to timber is expected to maintain its activities longer than a debarked one. Thus, to ensure prolonged quality, no debarking before storage is suggested: outer bark protects the inner bark, and debarking enhances the degradation.

Hygroscopic properties of thin dead outer bark layers strongly influence stem diameter variations on short and long time scales in Scots pine (Pinus sylvestris L.)

Time series of stem diameter variations (SDVs) recorded by dendrometers are composed of two components: (i) irreversible radial stem growth and (ii) reversible stem shrinking and swelling caused by dynamics in water storage in elastic tissues outside the cambium. However, SDVs measured over dead outer bark (periderm) could also be affected by absorption and evaporation of water from remaining dead bark layers after smoothing the stem surface to properly mount dendrometers. Therefore, the focus of this study was to determine the influence of hygroscopicity of a thin dead outer bark layer on the reversible component of dendrometer records of Scots pine (Pinus sylvestris) under field conditions. To accomplish this, SDVs deduced from dendrometers mounted over dead outer bark were compared among living and dead saplings and mature trees. Results revealed that dead trees showed high synchronicity in reversible daily SDVs compared to living trees throughout several growing seasons (mean Pearson correlation coefficient (r) = 0.844 among saplings and r = 0.902 among mature trees, respectively; P<0.001). Furthermore, diurnal and long-term SDVs closely followed changes in relative air humidity (RH) in living and dead trees. A multiple linear regression analysis of environmental influence on SDVs in dead and living trees revealed that the most important predictor of daily SDVs was RH (relative importance 64 %). Hence, results indicate that dendrometers mounted over dead outer bark with a thickness of <4 mm record hygroscopic shrinking and swelling of the bark tissue, which can amplify fluctuations in whole-tree water status. To conclude, hygroscopic processes must be taken into account when extracting intra-annual radial growth, determining environmental drivers of SDVs, and evaluating changes in tree water status from SDVs recorded by dendrometers, which were mounted over even thin dead outer bark layers.

Microwave assisted preparation of efficient activated carbon from grapevine rhytidome for the removal of methyl violet from aqueous solution

Grapevine rhytidome (the outer layer of bark on trunk), as an abundant and low-cost precursor, was used to prepare granular activated carbon with high surface area for the removal of methyl violet from aqueous solution. Microwave heating source was used to reduce the treatment time and energy consumption. To optimize the preparation, the effects of the different parameters, such as phosphoric acid concentration, acid/precursor weight ratio, impregnation time, microwave power, radiation time, and oven heating time on the ability of the samples for removal of methyl violet were studied. The obtained activated carbon was characterized by N 2 adsorption/desorption, SAXS, TEM and SEM methods. The adsorption of methyl violet onto the activated carbon was studied from both equilibrium and kinetic point of view and the results were compared with the commercial granular activated carbon. The rate of adsorption onto the prepared activated carbon was faster than commercial activated carbon. Different kinetic models were used to analyze the experimental kinetic data. The obtained activated carbon showed higher adsorption capacity (more than twice) for the adsorption of methyl violet in comparison with the commercial one. The equilibrium data were analyzed using different isotherm models. Adsorption was found to be maximum in the pH range 7–9.

The behaviour of scribbly gum moth larvae Ogmograptis sp. Meyrick (Lepidoptera: Bucculatricidae) in the Australian Capital Territory

Abstract Scribbles, the damage caused by mining larvae of the moth Ogmograptis sp. (Bucculatricidae), are a common sight on the trunks of many Eucalyptus species in eastern Australia. They provide a record of larval behaviour that can be easily measured when the trees shed outer bark layers. Measurements were made of scribbles on three species of eucalypt (Eucalyptus racemosa ssp. rossii, E. pauciflora and E. delegatensis) in the Australian Capital Territory. Scribble density varied between tree species and study sites but was consistently higher on the southern and eastern aspects of tree trunks. Some characteristics of mining behaviour, such as initial mining direction, were found to be random, but others including mine length and number of direction changes follow distinct patterns but differ between eucalypt species. It is likely that there is more than one species of Ogmograptis Meyrick as currently described (O. scribula Meyrick, from E. pauciflora) and each eucalypt species may be host to a different species of Ogmograptis.

Composition and quality of harvest residues and soil organic matter under windrow residue management in young hoop pine plantations as revealed by solid-state [formula omitted] NMR spectroscopy

Solid-state 13 C nuclear magnetic resonance (NMR) with cross-polarisation (CP) and magic-angle-spinning (MAS) was used to: (a) examine the changes in carbon (C) composition of windrowed harvest residues during the first 3 years of hoop pine plantations in subtropical Australia; (b) assess the impacts of windrowed harvest residues on soil organic matter (SOM) composition and quality in the 0–10 cm soil layer. Harvest residues were collected from 0-, 1-, 2- and 3-year-old windrows of ca. 2.5 m width (15 m apart for 0-, 1- and 2-year-old sites and 10 m apart for 3-year-old site). Soils from the 0 to 10 cm soil layer were collected from the 1-, 2- and 3-year-old sites. The 13 C NMR spectra of the harvest residues indicated the presence of lignin in the hoop pine wood, foliage and newly incorporated organic matter (NIOM). Condensed tannin structures were found in the decay-resistant bark, small wood and foliage, but were absent in other residue components and SOM. The NMR spectra of small wood samples contained condensed tannin structures because the outer layer of bark was not removed. NIOM showed a shift from foliage-like structures (celluloses) to lignin-type structures, indicating an incorporation of woody residues from the decomposing harvest residues. Suberins were also present in the small wood, foliage and bark. The 13 C CP NMR spectra of SOM indicated that in areas where windrows were present, SOM did not show compositional changes. However, an increase in SOM quality under the windrows in the second year after their formation as characterised by the alkyl C/ O-alkyl C (A/ O-A) ratio was mainly due to inputs from the decomposition of the labile, readily available components of the windrowed harvest residues.

Twenty-five years of biomonitoring lead in the Frankfurt/Main area.

The present study is an example of the historical monitoring of heavy metals. The specific question it aims to explore is: to what extent has the lead content of selected organisms used for biomonitoring in Frankfurt/Main--one of the cities in Germany most heavily affected by automobile traffic--changed as a result of legislation on leaded gasoline? Data on the lead content of the moss species Bryum argenteum Hedw. from the years 1974, 1975 and 1978 and data on the lead content of the outer bark of the ash species Fraxinus excelsior L. from 1973 served as the basis for the repeated measurements. Remeasurement was successful in 76.5% (i.e. 124 trees at 26 growth sites). The study produced the following results: As was expected, the lead content of the short-term accumulator Bryum argenteum Hedw. was distinctly lowered with a decreasing particulate lead concentration. However, the reduction factor varied greatly between the different growth sites. On the other hand, the lead content measured in the outer bark layers of Fraxinus excelsior L. has risen markedly during the past two decades. Whereas in 1973 nearly all trees examined displayed very low concentrations of lead (< 38 ppm), only 9.5% were still in this category in 1997 and nearly 30% exhibited high or even unacceptable lead concentrations (< 150 ppm-->225 ppm). Various factors have to be taken into account to explain this increase. First of all, bark is a long-term accumulator for heavy metals like lead and its enrichment capacity could have increased as the surface becomes rougher over time. Furthermore, lead is most probably leached out of the bark to a lesser degree now than in the 1970s, owing to the reduced concentration of sulphuric acid in the rain. The dramatic growth of automobile traffic in the Frankfurt/Main area during the period covered by the study undoubtedly plays an important role as well.

Use of tree bark to monitor radionuclide pollution.

The outer surface bark of many trees is an excellent monitoring source of fallout radionuclides. The accumulation and retention of these pollutants is evident by the presence of /sup 106/Ru, /sup 125/Sb, /sup 144/Ce and /sup 155/Eu in the outer layer of bark from many trees surveyed during this study. The accumulation and retention of these and other radionuclides suggest that tree bark is an ecosystem monitoring resource that should be exploited for these and possible other environmental pollutants. Therefore, the emphasis of this study was a broad survey of the detectability of gamma-ray emitting radionuclides in and on tree bark rather than a narrow quantitative study.

A New Laboratory Method Used for Investigating the Uptake, Translocation and Metabolism of Bark Banded Morphactin by Trees

AbstractCut twigs of Monterey pine(Pinus radiata D.Don) were banded with a 14C labelled morphactin formulation and the lower half of the twig placed in a Scholander type pressure bomb. Water was pumped through the twig from a reservoir inside the bomb and exudate collected from the protruding end of the twig. Using this method it was possible to determine that the slowest step in the translocation of morphactin was the passage across the outer layer of bark. Subsequent passage through the twig was not affected by girdling the bark suggesting that morphactin was translocated upwards via the xylem. The 14C compound in the exudate from live twigs differed from morphactin and was tentatively identified as the carboxylic acid derivative of the morphactin ester.The cut twig system facilitated studies on the uptake, metabolism and translocation of morphactin and should prove useful for studying the uptake and fate of other chemicals considered for bark application to trees.

Botryosphaeria ribis . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Botryosphaeria ribis . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Ribis grossularia . Also on Aesculus, Aleurites, Amygdalus, Araucaria, Atriplex, Baccharis, Bridelia, Carica, Caryota, Citrus, Cryptomeria, Cupressus, Diospyros, Eucalyptus, Fuchsia, Godetia, Gossypium, Grevillea, Juglans, Laguncularia, Ligustrum, Liquidambar, Liriodendron, Magnolia, Malus, Mangifera, Manihot, Melia, Monstera, Olea, Pandanus, Persea, Pinus, Pistacia, Plumeria, Prunus, Psidium, Pyrus, Quercus, Rhodoleia, Rhododendron, Ricinus, Rosa, Salix, Sambucus, Sesamum, Solanum ?, Tilia, Ulmus, Vitis and also isolated from human nails. DISEASE: Plurivorous, particularly on trees, and also causing rots in fruit (3, 725; 4, 636; 6, 106; 9, 344; 13, 249; 14, 196). Amongst the hosts on which it has been described causing dieback and cankers on branches and stems are: avocado ( Persea americana ; 31, 132; 35, 495); elm ( Ulmus ; 29, 587); apple ( Malus pumila ; 4, 178, 614; 36, 104; 49, 3370); currant ( Ribes spp.); Japanese cedar ( Cryptomeria japonica ; 39, 508); lemon ( Citrus limon ; 12, 283); pine ( Pinus spp. ; 47, 344); Rhododendron (43, 2296); sweet gum ( Liquidambar styraciflua ; 37, 317); Tilia spp. (30, 129); tuna ( Aleurites fordii and A. montana ; 29, 339; 32, 524); willow ( Salix ; 18, 486; 33, 455). B. ribes can also cause staining on timber (16, 578). On apple large, watery, blister-like cankers occur and these can destroy the main branches; young shoots and spurs are killed. The stromata form beneath the outer bark layers. On willow the girdling cankers are circular, crateriform, becoming dry and cracked. In tung there is a dieback of the terminal shoots from which spread takes place and cankers develop on the larger branches, with longitudinal bark splitting. In pines the killing of branch tips may lead to copious resin exudates. The imperfect state has been described more often in the field. On fruit a rot may occur after picking; this has been described for apple, avocado and lemon. GEOGRAPHICAL DISTRIBUTION: Widespread in temperate and tropical regions. TRANSMISSION: No experimental studies seem to have been described.

Hypoxylon Punctulatum and its Conidial Stage on Dead Oak Trees and in Culture

Among the fungi that appear frequently on standing dead oak-wilt trees in West Virginia are several species of Hypoxylon. The most common species, judging from field observations and isolations from wood of dead oaks, is H. punctulatum (Berk. & Rav.) Cke., which produces its black, shining, effused stromata within the bark of trunks and branches. The stromata are exposed only after the outer layer of bark has been thrown off. Closely associated with the fertile stromata of H. punctulatum and arising from about the same bark region, one frequently finds the darkened remains of a conidial fungus in the cracks of the bark. Collections of younger stages showed abundant production of light gray globose heads of conidia, which resemble young heads of Aspergillus. Specimens of both natural material and pure cultures were examined by Dr. S. J. Hughes, who confirmed the identification of this fungus as belonging to the genus Basidiobotrys. Two unsolved problems relating to H. punctulatum have prompted the investigations reported herein. These were first, the method by which the bark covering of the stroma is thrown off and second, the possible relationship of the conidial fungus to H. punctulatum. This paper reports the results of these investigations.