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Sample records for birch betula pendula

  1. Inter- and intra-specific variation in stem phloem phenolics of paper birch (Betula papyrifera) and European white birch (Betula pendula).

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    Muilenburg, V L; Phelan, P L; Bonello, P; Herms, D A

    2011-11-01

    Outbreaks of bronze birch borer (BBB) (Agrilus anxius), a wood-boring beetle endemic to North America, have been associated with widespread mortality of birch (Betula spp.). There is substantial inter- and intra-specific variation in birch resistance to BBB. Species endemic to North America, such as paper birch (B. papyrifera), have coevolved with BBB and are more resistant than European and Asian birch species, such as European white birch (B. pendula), which lack an evolutionary history with BBB. Borer larvae feed on stem phloem tissue. Therefore, in search of potential resistance mechanisms against BBB, we compared the constitutive phenolic profile of stem phloem tissue of paper birch with that of European white birch. We also analyzed intraspecific variation in phenolic composition among clones and/or half-siblings of both species. Three phenolics (coumaroylquinic acid, betuloside pentoside A, and a diarylheptanoid hexoside) were detected only in paper birch, and concentrations of six other phenolics were significantly higher in paper birch. These differences may contribute to the high resistance of paper birch to BBB relative to European white birch. There was significant intraspecific variation in four of 17 phenolics found in paper birch and in five of 14 found in European white birch, but clones and half-siblings within each species could not be distinguished by phenolic composition using multivariate analysis.

  2. Direct Emission of Methyvinylketone from Birch (\\textit{betula pendula})

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    Folkers, A.; Koppmann, R.; Wildt, J.

    2002-12-01

    Volatile organic compounds (VOCs) are of central importance for the chemistry of the troposphere. They have a significant impact on photochemical processes that lead to the formation of ozone and other photooxidants in the planetary boundary layer. With estimated global emission rates of 520 Tg yr {-1} [Guenther \\textit{et al.} 1995], biogenic emissions of short chained oxygenated VOCs (SOVOCs) like methanol, ethanol, acetaldehyde, and acetone cannot be neglected for atmospheric chemistry. In addition to the direct emission by plants SOVOCs are produced by chemical reactions of VOCs in the atmosphere. For some SOVOCs such as methanol, acetone, or leaf alcohols it is known that they have a large biogenic source strength. Other SOVOCs are believed to be only produced by atmospheric processes. For example methacrolein, and methylvinylketone (MVK) are believed to be exclusively produced during atmospheric isoprene oxidation. Thus, up to now the only known source of MVK in the atmosphere is the oxidation of VOCs like isoprene. We analysed SOVOC emissions from different plant species under well defined conditions in our plant chambers and determined the temperature- and light intensity dependence of their emission rates. During these measurements we also observed a direct MVK emission from birch. The emission rates exhibit a temperature and light intensity dependence. Artificial MVK formation was excluded by a series of experiments. Due to the direct emission of MVK probably also from other plant species than birch, measurements of ambient concentrations of this compound have to be carefully investigated. The fact that there may be a primary source for MVK has to be considered in model calculations concerning the photochemistry and the concentrations of OH radicals in the lower troposphere. \\begin{thebibliography}{} \\bibitem[Guenther \\textit{et al.} 1995]{Guenther1995} Guenther, A., Hewitt, C. N., Erickson, D., Fall, R., Geron, C., Graedel, T., Harley, P., Klinger, L

  3. Functional characterization of CCR in birch (Betula platyphylla × Betula pendula) through overexpression and suppression analysis.

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    Zhang, Wenbo; Wei, Rui; Chen, Su; Jiang, Jing; Li, Huiyu; Huang, Haijiao; Yang, Guang; Wang, Shuo; Wei, Hairong; Liu, Guifeng

    2015-06-01

    We cloned a Cinnamoyl-CoA Reductase gene (BpCCR1) from an apical meristem and first internode of Betula platyphylla and characterized its functions in lignin biosynthesis, wood formation and tree growth through transgenic approaches. We generated overexpression and suppression transgenic lines and analyzed them in comparison with the wild-type in terms of lignin content, anatomical characteristics, height and biomass. We found that BpCCR1 overexpression could increase lignin content up to 14.6%, and its underexpression decreased lignin content by 6.3%. Surprisingly, modification of BpCCR1 expression led to conspicuous changes in wood characteristics, including xylem vessel number and arrangement, and secondary wall thickness. The growth of transgenic trees in terms of height was also significantly influenced by the modification of BpCCR1 genes. We discuss the functions of BpCCR1 in the context of a phylogenetic tree built with CCR genes from multiple species.

  4. Hormesis and Paradoxical Effects of Drooping Birch (Betula pendula Roth Parameters Under Motor Traffic Pollution

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    Elena A. Erofeeva

    2015-06-01

    Full Text Available Various plant indexes are used or recommended for bioindication. However, the nonmonotonic dose–response dependences (hormesis and paradoxical effects of these indexes are insufficiently explored upon exposure to pollution. We studied the dependences of these Betula pendula indexes on the intensity of motor traffic pollution. Regression analysis did not reveal any dependence of chlorophyll and carotenoid content on traffic intensity (in 2008 and 2010-2013. Lipid peroxidation rate had different versions of paradoxical effects in 2008 and 2010 to 2012 and increased in comparison with control under an increase in pollution level in 2013. In 2010 to 2012, all dose–response dependences for total protein and thiol group content were biphasic and multiphasic paradoxical effects. In 2013, an increase in traffic intensity induced a linear reduction in protein content and an increase in thiol group level in comparison with the control. In most cases, the studied phenological indexes and seed production decreased monotonically in comparison with the control following an increase in traffic intensity. Only in 2010 and 2013, share of fallen leaves had hormesis and paradoxical effect accordingly. Fluctuating asymmetry had a paradoxical effect and hormesis in 2008 and 2012, accordingly, and increased in comparison with the control under an increase in the level of pollution in 2010 to 2011.

  5. Hormesis and Paradoxical Effects of Drooping Birch (Betula pendula Roth) Parameters Under Motor Traffic Pollution.

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    Erofeeva, Elena A

    2015-01-01

    Various plant indexes are used or recommended for bioindication. However, the nonmonotonic dose-response dependences (hormesis and paradoxical effects) of these indexes are insufficiently explored upon exposure to pollution. We studied the dependences of these Betula pendula indexes on the intensity of motor traffic pollution. Regression analysis did not reveal any dependence of chlorophyll and carotenoid content on traffic intensity (in 2008 and 2010-2013). Lipid peroxidation rate had different versions of paradoxical effects in 2008 and 2010 to 2012 and increased in comparison with control under an increase in pollution level in 2013. In 2010 to 2012, all dose-response dependences for total protein and thiol group content were biphasic and multiphasic paradoxical effects. In 2013, an increase in traffic intensity induced a linear reduction in protein content and an increase in thiol group level in comparison with the control. In most cases, the studied phenological indexes and seed production decreased monotonically in comparison with the control following an increase in traffic intensity. Only in 2010 and 2013, share of fallen leaves had hormesis and paradoxical effect accordingly. Fluctuating asymmetry had a paradoxical effect and hormesis in 2008 and 2012, accordingly, and increased in comparison with the control under an increase in the level of pollution in 2010 to 2011.

  6. Elevated air humidity affects hydraulic traits and tree size but not biomass allocation in young silver birches (Betula pendula

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    Arne eSellin

    2015-10-01

    Full Text Available As changes in air temperature, precipitation, and air humidity are expected in the coming decades, studies on the impact of these environmental shifts on plant growth and functioning are of major importance. Greatly understudied aspects of climate change include consequences of increasing air humidity on forest ecosystems, predicted for high latitudes. The main objective of this study was to find a link between hydraulic acclimation and shifts in trees’ resource allocation in silver birch (Betula pendula Roth in response to elevated air relative humidity (RH. A second question was whether the changes in hydraulic architecture depend on tree size. Two years of application of increased RH decreased the biomass accumulation in birch saplings, but the biomass partitioning among aboveground parts (leaves, branches, and stems remained unaffected. Increased stem Huber values (xylem cross-sectional area to leaf area ratio observed in trees under elevated RH did not entail changes in the ratio of non-photosynthetic to photosynthetic tissues. The reduction of stem-wood density is attributable to diminished mechanical load imposed on the stem, since humidified trees had relatively shorter crowns. Growing under higher RH caused hydraulic conductance of the root system (KR to increase, while KR (expressed per unit leaf area decreased and leaf hydraulic conductance increased with tree size. Saplings of silver birch acclimate to increasing air humidity by adjusting plant morphology (live crown length, slenderness, specific leaf area, and fine-root traits and wood density rather than biomass distribution among aboveground organs. The treatment had a significant effect on several hydraulic properties of the trees, while the shifts were largely associated with changes in tree size but not in biomass allocation.

  7. Phylogeny of chitinases and its implications for estimating horizontal gene transfer from chitinase-transgenic silver birch (Betula pendula).

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    Lohtander, Katileena; Pasonen, Hanna-Leena; Aalto, Markku K; Palva, Tapio; Pappinen, Ari; Rikkinen, Jouko

    2008-01-01

    Chitinases are hydrolytic enzymes that have been employed in biotechnology in attempts to increase plants' resistance against fungal pathogens. Genetically modified plants have given rise to concerns of the spreading of transgenes into the environment through vertical or horizontal gene transfer (HGT). In this study, chitinase-like sequences from silver birch (Betula pendula) EST-libraries were identified and their phylogenetic relationships to other chitinases were studied. Phylogenetic analyses were used to estimate the frequency of historical gene transfer events of chitinase genes between plants and other organisms, and the usefulness of phylogenetic analyses as a source of information for the risk assessment of transgenic silver birch carrying a sugar beet chitinase IV gene was evaluated. Thirteen partial chitinase-like sequences, with an approximate length of 600 bp, were obtained from the EST-libraries. The sequences belonged to five chitinase classes. Some bacterial chitinases from Streptomyces and Burkholderia, as well as a chitinase from an oomycete, Phytophthora infestans, grouped together with the class IV chitinases of plants, supporting the hypothesis that some class IV chitinases in bacteria have evolved from eukaryotic chitinases via horizontal gene transfer. According to our analyses, HGT of a chitinase IV gene from eukaryotes to bacteria has presumably occurred only once. Based on this, the likelihood for the HGT of chitinase IV gene from transgenic birch to other organisms is extremely low. However, as risk is a function of both the likelihood and consequences of an event, the effects of rare HGT event(s) will finally determine the level of the risk.

  8. Effects of long-term, elevated ultraviolet-B radiation on phytochemicals in the bark of silver birch (Betula pendula).

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    Tegelberg, Riitta; Aphalo, Pedro J; Julkunen-Tiitto, Riitta

    2002-12-01

    Long-term outdoor experiments were conducted to investigate the effects of elevated ultraviolet-B (UV-B, 280-320 nm) radiation on secondary metabolites (phenolics and terpenoids) and the main soluble sugars (sucrose, raffinose and glucose) in the bark of silver birch (Betula pendula Roth) saplings. Saplings were exposed to a constant 50% increase in erythemal UV irradiance (UV-B(CIE); based on the CIE (International Commission on Illumination) erythemal action spectrum) and a small increase in UV-A radiation (320-400 nm) for three growing seasons in an irradiation field in central Finland. Two control groups were used: saplings exposed to ambient radiation and saplings exposed to slightly increased UV-A radiation. Concentrations of sucrose, raffinose and glucose in bark were higher in UV-treated saplings than in saplings grown in ambient radiation, indicating that stem carbohydrate metabolism was changed by long-term elevated UV radiation. Saplings in the elevated UV-A + UV-B radiation treatment and the UV-A radiation control treatment had significantly increased concentrations of certain UV-absorbing phenolics, such as salidroside, 3,4'-dihydroxypropiophenone-3-glucoside, (+)-catechin and (-)-epicatechin compared with saplings in ambient radiation. In contrast, the radiation treatments had no effect on the non-UV-B-absorbing terpenoids, papyriferic acid and deacetylpapyriferic acid. We conclude that plant parts, in addition to leaves, accumulate specific phenolic UV-filters in response to UV radiation exposure.

  9. Field performance of chitinase transgenic silver birches (Betula pendula): resistance to fungal diseases.

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    Pasonen, H-L; Seppänen, S-K; Degefu, Y; Rytkönen, A; von Weissenberg, K; Pappinen, A

    2004-08-01

    A field trial of 15 transgenic birch lines expressing a sugar beet chitinase IV gene and the corresponding controls was established in southern Finland to study the effects of the level of sugar beet chitinase IV expression on birch resistance to fungal diseases. The symptoms caused by natural infections of two fungal pathogens, Pyrenopeziza betulicola (leaf spot disease) and Melampsoridium betulinum (birch rust), were analysed in the field during a period of 3 years. The lines that had shown a high level of sugar beet chitinase IV mRNA accumulation in the greenhouse also showed high sugar beet chitinase IV expression after 3 years in the field. The level of sugar beet chitinase IV expression did not significantly improve the resistance of transgenic birches to leaf spot disease. Instead, some transgenic lines were significantly more susceptible to leaf spot than the controls. The level of sugar beet chitinase IV expression did have an improving effect on most parameters of birch rust; the groups of lines showing high or intermediate transgene expression were more resistant to birch rust than those showing low expression. This result indicates that the tested transformation may provide a tool for increasing the resistance of silver birch to birch rust.

  10. Modelling of the spring phenological phases of the Silver birch Betula pendula and Bird cherry Padus racemosa in Baltic region

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    Kalvāns, Andis; Kalvāne, Gunta; Bitāne, Māra; Cepīte-Frišfelde, Daiga; Sīle, Tija; Seņņikovs, Juris

    2014-05-01

    The air temperature is the strongest driving factor of the plant development during spring time in moderate climate conditions. However other factors such as the air temperature during the dormancy period and light conditions can play a role as well. The full potential of the recent and historical phenological observation data can be utilised by modelling tools. We have calibrated seven phenological models described in scientific literature to calculate the likely dates leaf unfolding and start of flowering of the Silver birch Betula pendula and bird cherry Padus racemosa (Kalvāns at al, accepted). Phenological observations are derived from voluntary observation network for period 1960-2009 in Latvia. The number of used observations for each phase range from 149 to 172. Air temperature data measured in meteorological stations closest to the corresponding phenological observation sites are obtained from Latvian Environment, Geology and Meteorology Centre. We used 33 random data subsamples for model calibration to produce a range of model coefficients enabling the estimation of the phenological model uncertainty. It is found that the best reproduction of the observational data are obtained using a simple linear degree day model considering daily minimum and maximum temperature and more complex sigmoidal model honouring the need for low temperatures for dormancy release (UniChill, Chuine, 2000). The median calibration base temperature in the degree day model for the silver birch leaf unfolding is 5.6°C and for start of the flowering 6.7°C; for the bird cherry the corresponding base temperatures are 3.2°C and 3.4°C. The calibrated models and air temperature archive data derived from the Danish Meteorological Institute is used to simulate the respective phase onset in the Estonia, Latvia and Lithuania in 2009. Significant regional differences between modelled phase onset times are observed. There is a wide regional variation of the model uncertainty as well

  11. Long-term development of experimental mixtures of Scots pine (Pinus sylvestris L. and silver birch (Betula pendula Roth. in northern Britain

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    Bill Mason

    2016-07-01

    Full Text Available The Caledonian pinewoods of northern Scotland are a priority conservation habitat in Europe which are dominated by Scots pine (Pinus sylvestris, but varying proportions of a number of broadleaved species such as silver birch (Betula pendula can occur in these forests. Better understanding of the dynamics of mixed Scots pine-birch stands would be helpful in informing current initiatives to restore and increase the area of the pinewood ecosystem. Some evidence is provided by two experiments established in the 1960s which compared plots of pure Scots pine and pure birch with two treatments where the two species were mixed in 3:1 and 1:1 ratios. Some fifty years later, Scots pine was the more vigorous of the two species in these experiments, being both taller and significantly larger in diameter. The highest basal area was generally found in the pure Scots pine plots and the values in the mixed plots tended to be intermediate between those of the two component species. Examination of the growth in the mixed plots showed a slight, but non-significant, tendency towards overyielding. This appeared to be due to Scots pine growth being better than predicted, while that of birch was slightly less than predicted. These results suggest that in these mixtures, which are composed of two light demanding species, the main mechanism driving long-term performance is competition for light and there is little evidence of any complementary effect. These results suggest that any strategy seeking to increase the long-term representation of broadleaves such as birch in the Caledonian pinewoods will need to create discrete blocks that are large enough to withstand the competitive pressures exerted by the pine.

  12. Density and composition of an insect population in a field trial of chitinase transgenic and wild-type silver birch (Betula pendula) clones.

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    Vihervuori, Liisa; Pasonen, Hanna-Leena; Lyytikäinen-Saarenmaa, Päivi

    2008-12-01

    Fifteen silver birch (Betula pendula Roth) lines carrying a sugar beet chitinase IV gene and eight wild-type birch clones were grown in a field trial. The composition and density of the insect population and the leaf damage caused by insects were monitored and compared between transgenic and wild-type trees. The most abundant insect group in all trees was aphids, and the variation in total insect densities was mainly explained by the variation in aphid densities. Insect densities were generally higher in the transgenic than in the control trees, indicating that the expression of the sugar beet chitinase IV gene had an influence on the suitability of birch leaves to aphids. The level of leaf damage was higher among transgenic than among control trees. Chewing damage was the most common type of leaf damage in all trees. The number of different damage types was higher among the wild-type clones than among the transgenic lines or their controls. The results indicate that the chitinase transgenic trees are more susceptible to aphids and suffer higher levels of leaf damage than the control trees. In the composition of the damage types, the control trees were more similar to the transgenic than to other wild-type trees, indicating that the composition was mostly linked to the genotype of the tree and not to the expression of the transgene. This study provides important information on the ecological interactions of chitinase transgenic trees in the field trial. No clear harmful effects of transgenic chitinase on the biodiversity of insect population were detected.

  13. Effects of long-term elevated ultraviolet-B radiation on phytochemicals in the bark of silver birch (Betula pendula)

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    Tegelberg, R.; Julkunen-Tiitto, R. [Joensuu Univ., Dept. of Biology, Joensuu (Finland); Aphalo, P. J. [Joensuu Univ., Faculty of Forestry, Joensuu (Finland)

    2002-12-01

    The effects of long-term ultraviolet-B radiation on the concentrations of secondary metabolites such as phenolics and terpenoids in the bark of silver birch saplings were studied. The effects of ultraviolet-B on the concentrations of the main soluble sugars such as sucrose, raffinose, and glucose in silver birch stem were also investigated, given that they are involved in the transpiration and allocation of assimilated carbon, and UV-B-induced changes may affect tree growth. Concentrations of sucrose, raffinose and glucose in bark were found to be higher in UV-treated saplings than in saplings grown in ambient radiation, indicating that stem carbohydrate metabolism was changed by long-term exposure to elevated UV radiation. Saplings in elevated UV-A + UV-B radiation treatment and UV-A radiation control treatment had shown significantly increased concentrations of certain UV-absorbing phenolics compared with saplings in ambient radiation. No effect of radiation treatment was observed on non-UV-B-absorbing terpenoids. These observations led to the conclusion that plant parts accumulate specific phenolic UV-filters in response to UV radiation exposure. The accumulation of sugars in the stems of silver birch saplings in response to UV radiation is believed to affect tree growth, possibly because of a reduction of alpha-cellulose content and consequent reduction in cell wall production. 36 refs., 1 tab., 2 figs.

  14. Quantification of overnight movement of birch (Betula pendula branches and foliage with short interval terrestrial laser scanning

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    Eetu ePuttonen

    2016-02-01

    Full Text Available The goal of the study was to determine circadian movements of silver birch (Petula Bendula branches and foliage detected with terrestrial laser scanning (TLS. The study consisted of two geographically separate experiments conducted in Finland and in Austria. Both experiments were carried out at the same time of the year and under similar outdoor conditions. Experiments consisted of 14 (Finland and 77 (Austria individual laser scans taken between sunset and sunrise. The resulting point clouds were used in creating a time series of branch movements. In the Finnish data, the vertical movement of the whole tree crown was monitored due to low volumetric point density. In the Austrian data, movements of manually selected representative points on branches were monitored. The movements were monitored from dusk until morning hours in order to avoid daytime wind effects. The results indicated that height deciles of the Finnish birch crown had vertical movements between -10.0 and 5.0 cm compared to the situation at sunset. In the Austrian data, the maximum detected representative point movement was 10.0 cm. The temporal development of the movements followed a highly similar pattern in both experiments, with the maximum movements occurring about an hour and a half before (Austria or around (Finland sunrise. The results demonstrate the potential of terrestrial laser scanning measurements in support of chronobiology.

  15. Cultivable actinomycetes from rhizosphere of birch (Betula pendula) growing on a coal mine dump in Silets, Ukraine.

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    Ostash, Bohdan; Gren, Tetiana; Hrubskyy, Yaroslav; Tistechok, Stepan; Beshley, Stepan; Baranov, Volodymyr; Fedorenko, Victor

    2014-08-01

    Five actinomycete strains were isolated from the rhizosphere of birch, one of a few native tree forms capable of thriving on the upper level of a coal mine dump near the village of Silets (Lvivska region, Ukraine). No such strains were isolated from surrounding gangue, or from nearby grass Calamagrostis epigeios. Using 16S rDNA sequencing and analysis of cell wall aminoacids, four of these strains were shown to belong to genus Streptomyces and one to be Amycolatopsis. The isolates were able to produce siderophores and antibacterial compounds. In comparison to the reference strain Streptomyces coelicolor M145, certain rhizospheric isolates displayed somewhat increased survival in the presence of copper, iron(III), or chromium(VI) salts. The Amycolatopsis isolate was also shown to accumulate significant quantities of heavy metals from waste extracts. Possible roles of the described strains in coal mine dump ecology are discussed.

  16. Interspecific variation in resistance of Asian, European, and North American birches (Betula spp.) to bronze birch borer (Coleoptera: Buprestidae).

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    Nielsen, David G; Muilenburg, Vanessa L; Herms, Daniel A

    2011-06-01

    Bronze birch borer (Agrilus anxius Gory) is the key pest of birches (Betula spp.) in North America, several of which have been recommended for ornamental landscapes based on anecdotal reports of borer resistance that had not been confirmed experimentally. In a 20-yr common garden experiment initiated in 1979 in Ohio, North American birch species, including paper birch (Betula papyrifera Marshall), 'Whitespire' gray birch (Betula populifolia Marshall), and river birch (Betula nigra L.), were much more resistant to bronze birch borer than species indigenous to Europe and Asia, including European white birch (Betula pendula Roth), downy birch (Betula pubescens Ehrh.), monarch birch (Betula maximowicziana Regel), and Szechuan white birch (Betula szechuanica Jansson). Within 8 yr of planting, every European white, downy, and Szechuan birch had been colonized and killed, although 100% of monarch birch had been colonized and 88% of these plants were killed after nine years. Conversely, 97% of river birch, 76% of paper birch, and 73% Whitespire gray birch were alive 20 yr after planting, and river birch showed no evidence of colonization. This pattern is consistent with biogeographic theory of plant defense: North American birch species that share a coevolutionary history with bronze birch borer were much more resistant than naïve hosts endemic to Europe and Asia, possibly by virtue of evolution of targeted defenses. This information suggests that if bronze birch borer were introduced to Europe or Asia, it could threaten its hosts there on a continental scale. This study also exposed limitations of anecdotal observation as evidence of host plant resistance.

  17. Accumulative response of Scots pine (Pinus sylvestris L.) and silver birch (Betula pendula Roth) to heavy metals enhanced by Pb-Zn ore mining and processing plants: Explicitly spatial considerations of ordinary kriging based on a GIS approach.

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    Pająk, Marek; Halecki, Wiktor; Gąsiorek, Michał

    2017-02-01

    Plants have an accumulative response to heavy metals present in soils or deposited from airborne sources of emissions. Therefore, their tissues are very often used in studies of heavy metal contamination originating from different sources as a bioindicator of environmental pollution. This research was undertaken to examine accumulation capacities of Pb, Zn, Cd, Cu and Cr in washed and unwashed needles of Scots pine (Pinus sylvestris L.) and leaves of silver birch (Betula pendula Roth) growing in a contaminated area. We collected needles of Scots pine and leaves of silver birch in an area around a sedimentation pond and metallurgic plant processing Pb and Zn ores near Olkusz, Poland. Concentrations of heavy metals, which have been linked with exposure to emissions, were determined from foliar samples collected at 33 sites. These sites were established at various distances (0.5-3.6 km) from the pond and metallurgic plant so as to identify the predominant accumulative response of plants. Spatial gradients for Pb and Zn were calculated using an ordinary kriging interpolation algorithm. A spatial pattern was identified by a GIS method to visualize maps over the Pb-Zn ore mining area. The accumulation of Zn (R(2) = 0.74, p < 0.05) and Pb (R(2) = 0.85, p < 0.01) in plant tissues correlated with soil concentrations. This tendency was not found in the case of Cu, Cd and Cr.

  18. Survival and growth for pubescent birch, pendula birch and common alder growing on farmland areas; Oeverlevnad och tillvaext hos glasbjoerk, vaartbjoerk och klibbal planterade paa aakermark

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    Johansson, Tord

    2000-07-01

    Pendula birches (Betula pendula Roth) and pubescent birches (Betula pubescens Ehrh.) were planted on former farmland. Before planting, the ground was harrowed or the ground was sprayed with terbuthylazine. Tree shelters were used as protection against weeds, voles and wild habitat. Birches treated with terbuthylazine showed the lowest survival. Birches growing in tree shelters were tallest and those growing on spots treated with terbuthylazine were smallest. The diameter at 0.1 m did not differ in a statistically significant way between the treatments. In another experiment with different herbicides, common alder (Alnus glutinosa (L.) Gaertn.) and pendula birch (Betula pendula Roth) were planted on former farmland that had been treated with glyphosate, terbuthylazine and propyzamide or after ground had been harrowed or not treated. In the study on herbicide-treated plants, birch had the highest plant survival. Mostly, species treated with glyphosate were thicker than species treated in other ways. Both species appeared sensitive to terbuthylazine, but not to glyphosate. Birch was not sensitive for propyzamide in opposite to alder. Some practical recommendations concerning afforestation of former farmland, especially weeding, are given.

  19. Betula pendula: A Promising Candidate for Phytoremediation of TCE in Northern Climates.

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    Lewis, Jeffrey; Qvarfort, Ulf; Sjöström, Jan

    2015-01-01

    Betula pendula (Silver birch) trees growing on two contaminated sites were evaluated to assess their capacity to phytoscreen and phytoremediate chlorinated aliphatic compounds and heavy metals. Both locations are industrially-contaminated properties in central Sweden. The first was the site of a trichloroethylene (TCE) spill in the 1980s while the second was polluted with heavy metals by burning industrial wastes. In both cases, sap and sapwood from Silver birch trees were collected and analyzed for either chlorinated aliphatic compounds or heavy metals. These results were compared to analyses of the surface soil, vadose zone pore air and groundwater. Silver birch demonstrated the potential to phytoscreen and possibly phytoremediate TCE and related compounds, but it did not demonstrate the ability to effectively phytoextract heavy metals when compared with hyperaccumulator plants. The capacity of Silver birch to phytoremediate TCE appears comparable to tree species that have been employed in field-scale TCE phytoremediation efforts, such as Populus spp. and Eucalyptus sideroxylon rosea.

  20. Nitrate reductase activity in some subarctic species and UV influence in the foliage of Betula pendula Roth. seedlings.

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    Krywult, Marek; Turunen, Minna; Sutinen, Marja-Liisa; Derome, Kirsti; Norokorpi, Yrjö

    2002-02-04

    Nitrate reductase (NR) activity was studied in the foliage of five subarctic species: mature trees of European white birch (Betula pubescens Erch. S.S.), Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L. Karst), Ericaceous shrub bilberry (Vaccinium myrtillus L.), naturally growing in a forest, and seed-grown silver birch (Betula pendula Roth.) seedlings in an ultraviolet (UV) exclusion field experiment at the Pallas-Ounastunturi National Park in Finnish Lapland (68 degrees N). Mean NR activity ranged from 0 in bilberry to 1477 (S.D. = 277.7) and 1910 (S.D. = 785.4) nmol g(-1) DW h(-1) in mature trees of European white birch and silver birch seedlings, respectively. Significant differences due to UV exclosure treatments were determined for the NR activity of silver birch seedlings (F = 3.62, P= 0.025*) after three growing seasons (191 days) of UV exclusion. The ambient and control silver birch seedlings had or tended to have higher NR activity than those grown under UV exclusion. No relationship was found between the foliage NR activity and total nitrogen content, which ranged from 0.61 to 1.35% per seedling. The present study suggests large differences in NR activity between the species and the induction of NR activity in silver birch seedlings due to ambient UV radiation.

  1. Foliar fungi of Betula pendula: impact of tree species mixtures and assessment methods

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    Nguyen, Diem; Boberg, Johanna; Cleary, Michelle; Bruelheide, Helge; Hönig, Lydia; Koricheva, Julia; Stenlid, Jan

    2017-02-01

    Foliar fungi of silver birch (Betula pendula) in an experimental Finnish forest were investigated across a gradient of tree species richness using molecular high-throughput sequencing and visual macroscopic assessment. We hypothesized that the molecular approach detects more fungal taxa than visual assessment, and that there is a relationship among the most common fungal taxa detected by both techniques. Furthermore, we hypothesized that the fungal community composition, diversity, and distribution patterns are affected by changes in tree diversity. Sequencing revealed greater diversity of fungi on birch leaves than the visual assessment method. One species showed a linear relationship between the methods. Species-specific variation in fungal community composition could be partially explained by tree diversity, though overall fungal diversity was not affected by tree diversity. Analysis of specific fungal taxa indicated tree diversity effects at the local neighbourhood scale, where the proportion of birch among neighbouring trees varied, but not at the plot scale. In conclusion, both methods may be used to determine tree diversity effects on the foliar fungal community. However, high-throughput sequencing provided higher resolution of the fungal community, while the visual macroscopic assessment detected functionally active fungal species.

  2. Titanium dioxide (TiO2) fine particle capture and BVOC emissions of Betula pendula and Betula pubescens at different wind speeds

    Science.gov (United States)

    Räsänen, Janne V.; Leskinen, Jari T. T.; Holopainen, Toini; Joutsensaari, Jorma; Pasanen, Pertti; Kivimäenpää, Minna

    2017-03-01

    Trees are known to affect air quality by capturing a remarkable amount of particles from the atmosphere. However, the significance of trees in removing very fine particles (diameter less than 0.5 μm) is not well understood. We determined particle capture efficiency (Cp) of two birch species: Betula pendula and Betula pubescens by using inert titanium dioxide fine particles (TiO2, geometric mean diameter 0.270 μm) at three wind speeds (1, 3 and 6 ms-1) in a wind tunnel. Capture efficiencies were determined by measuring densities of TiO2 particles on leaf surfaces by scanning electron microscopy. In addition, the particle intake into an inner structure of leaves was studied by transmission electron microscopy. The effects of fine particle exposure and wind speed on emission rates of biogenic volatile organic compounds (BVOCs) were measured. Particles were captured (Cp) equally efficiently on foliage of B. pendula (0.0026 ± 0.0005) % and B. pubescens (0.0025 ± 0.0006) %. Increasing wind speed significantly decreased Cp. Increasing wind speed increased deposition velocity (Vg) on B. pendula but not on B. pubescens. Particles were deposited more efficiently on the underside of B. pendula leaves, whereas deposition was similar on the upper and under sides of B. pubescens leaves. TiO2 particles were found inside three of five B. pendula leaves exposed to particles at a wind speed of 1 ms-1 indicating that particles can penetrate into the plant structure. Emission rates of several mono-, homo- and sesquiterpenes were highest at a wind speed of 3 ms-1 in B. pendula. In B. pubescens, emission rates of a few monoterpenes and nonanal decreased linearly with wind speed, but emission rates of sesquiterpenes were lowest at 3 ms-1 and increased at 6 ms-1. Emission rates of a few green leaf volatile compounds increased with increasing wind speed in both species. The results of this study suggest that the surface structure of trees is less important for capturing particles with

  3. Ultraviolet-B-induced flavonoid accumulation in Betula pendula leaves is dependent upon nitrate reductase-mediated nitric oxide signaling.

    Science.gov (United States)

    Zhang, Ming; Dong, Ju-Fang; Jin, Hai-Hong; Sun, Li-Na; Xu, Mao-Jun

    2011-08-01

    Nitric oxide (NO) is an important signaling molecule involved in many physiological processes in plants. Nitric oxide generation and flavonoid accumulation are two early reactions of plants to ultraviolet-B (UV-B) irradiation. However, the source of UV-B-triggered NO generation and the role of NO in UV-B-induced flavonoid accumulation are not fully understood. In order to evaluate the origin of UV-B-triggered NO generation, we examined the responses of nitrate reductase (NR) activity and the expression levels of NIA1 and NIA2 genes in leaves of Betula pendula Roth (silver birch) seedlings to UV-B irradiation. The data show that UV-B irradiation stimulates NR activity and induces up-regulation of NIA1 but does not affect NIA2 expression during UV-B-triggered NO generation. Pretreatment of the leaves with NR inhibitors tungstate (TUN) and glutamine (Gln) abolishes not only UV-B-triggered NR activities but also UV-B-induced NO generation. Furthermore, application of TUN and Gln suppresses UV-B-induced flavonoid production in the leaves and the suppression of NR inhibitors on UV-B-induced flavonoid production can be reversed by NO via its donor sodium nitroprusside. Together, the data indicate that NIA1 in the leaves of silver birch seedlings is sensitive to UV-B and the UV-B-induced up-regulation of NIA1 may lead to enhancement of NR activity. Furthermore, our results demonstrate that NR is involved in UV-B-triggered NO generation and NR-mediated NO generation is essential for UV-B-induced flavonoid accumulation in silver birch leaves.

  4. Ultrastructural changes in chloroplasts of mesophyll cells of chlorotic and prematurely yellowed leaves of Betula pendula Rothr

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    Krystyna Przybył

    2011-04-01

    Full Text Available The ultrastructure of chloroplasts was studied in mesophyll cells of the leaves of silver birch (Betula pendula showing interveinal chlorosis or premature yellowing, in comparison with leaves without symptoms or exhibiting symptoms of natural senescence. The leaves were collected between May 26 to June 7 and additionally in the September 10-12 from the upper part of the crown, from increments of the past four years. No major difference in ultrastructure of chloroplasts was found between spongy and palisade mesophyll cells. The following senescencerelated changes were observed in chloroplasts of prematurely yellowed leaves and showing inteveinal chlorosis: reduced chloroplast size, degeneration of the membrane systems of thylakoids and increased electron density of plastoglobuli. The most electron dark globules (lipid droplets were found together with starch grains in cells of spongy mesophyll of leaves showing interveinal chlorosis. Abnormal, spherical and rounded chloroplasts with electron-dark inside of thylakoids or the electron-dark stroma between thylakoids were found only in yellowed and chlorotic leaves in spring.

  5. Temporal variation in epidermal flavonoids due to altered solar UV radiation is moderated by the leaf position in Betula pendula.

    Science.gov (United States)

    Morales, Luis O; Tegelberg, Riitta; Brosché, Mikael; Lindfors, Anders; Siipola, Sari; Aphalo, Pedro J

    2011-11-01

    The physiological mechanisms controlling plant responses to dynamic changes in ambient solar ultraviolet (UV) radiation are not fully understood: this information is important to further comprehend plant adaptation to their natural habitats. We used the fluorimeter Dualex to estimate in vivo the epidermal flavonoid contents by measuring epidermal UV absorbance (A(375) ) in Betula pendula Roth (silver birch) leaves of different ages under altered UV. Seedlings were grown in a greenhouse for 15 days without UV and transferred outdoors under three UV treatments (UV-0, UV-A and UV-A+B) created by three types of plastic film. After 7 and 13 days, Dualex measurements were taken at adaxial and abaxial epidermis of the first three leaves (L1, L2 and L3) of the seedlings. After 14 days, some of the seedlings were reciprocally swapped amongst the treatments to study the accumulation of epidermal flavonoids in the youngest unfolded leaves (L3) during leaf expansion under changing solar UV environments. A(375) of the leaves responded differently to the UV treatment depending on their position. UV-B increased the A(375) in the leaves independently of leaf position. L3 quickly adjusted A(375) in their epidermis according to the UV they received and these adjustments were affected by previous UV exposure. The initial absence of UV-A+B or UV-A, followed by exposure to UV-A+B, particularly enhanced leaf A(375) . Silver birch leaves modulate their protective pigments in response to changes in the UV environment during their expansion, and their previous UV exposure history affects the epidermal-absorbance achieved during later UV exposure.

  6. The influence of hybridization on epidermal properties of birch species and the consequences for palaeoclimatic interpretations

    NARCIS (Netherlands)

    Wagner, F.; Kürschner, W.M.; Neuvonen, S.; Visscher, H.

    2000-01-01

    The Fennoscandian birch population primarily consists of Betula nana, B. pendula and B. pubescens ssp. czerepanovii, the Mountain birch. Frequent hybridization between the Mountain birch and B. nana generates a wide range of genotypic and phenotypic plasticity in the subarctic birch zone of Fennosca

  7. CHANGES OF CUTICLE SURFACE LIPIDS OF POPULUS ITALICA AND BETULA PENDULA CAUSED BY POLLUTION

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    Zubrovskaya O. M.

    2014-08-01

    Full Text Available Arboreal plants intensively accumulate heavy metals, resulting in a corresponding revocation level of physiological processes. The lipid components operate an important role in the formation of plant resistance. Therefore, it was very important to determine the characteristics of lipid peroxidation flow in leaves of arboreal plants, and changes in the composition of cuticle surface lipids at different levels of heavy metal accumulation. Research objects were Populus italica (Du Roi Moench and Betula pendula Roth. of second age group, growing on the industrial site РJSC ‘Kryvyi Rig Factory of minium’ (with strong contamination and in the arboretum of Kryvyi Rig Botanic Garden, National Academy of Science of Ukraine (conventional control. Leaves were taken from the middle of the crown southwest exposure in phase of leaf full separation and 5-10 day of phase finishing point of their growth. It was shown that P. italica maximally accumulated zinc, content of which was increased in the phase of leaf full separation and on 5-10 day of phase of leaf growth finishing point relative to the control to 12,6 and 23 times respectively. The accumulation level of heavy metals was typically less significant for assimilation organs of B. pendula compared to P. italica. Thus, the content of zinc and lead in the leaves during the study increased only in 2 times towards control. The leaves of B. pendula, unlike P. italica, more intensively accumulated cadmium in the phase of leaf full separation and on 5-10 day of phase finishing point of their growth (it was 6 and 15 times higher relative to control respectively. It was obviously connected to the fact that the surface texture of poplar leaves may cause intense sticking of dust particles containing heavy metals and penetration into the leaves. The effect of heavy metals in both phases of leaf morphogenesis caused an increase in lipid peroxidation by 40-52% for P. italica and almost by 3 times for B. pendula

  8. CHANGES OF CUTICLE SURFACE LIPIDS OF POPULUS ITALICA AND BETULA PENDULA CAUSED BY POLLUTION

    Directory of Open Access Journals (Sweden)

    O. M. Zubrovskaya

    2014-08-01

    Full Text Available Arboreal plants intensively accumulate heavy metals, resulting in a corresponding revocation level of physiological processes. The lipid components operate an important role in the formation of plant resistance. Therefore, it was very important to determine the characteristics of lipid peroxidation flow in leaves of arboreal plants, and changes in the composition of cuticle surface lipids at different levels of heavy metal accumulation. Research objects were Populus italica (Du Roi Moench and Betula pendula Roth. of second age group, growing on the industrial site РJSC ‘Kryvyi Rig Factory of minium’ (with strong contamination and in the arboretum of Kryvyi Rig Botanic Garden, National Academy of Science of Ukraine (conventional control. Leaves were taken from the middle of the crown southwest exposure in phase of leaf full separation and 5-10 day of phase finishing point of their growth. It was shown that P. italica maximally accumulated zinc, content of which was increased in the phase of leaf full separation and on 5-10 day of phase of leaf growth finishing point relative to the control to 12,6 and 23 times respectively. The accumulation level of heavy metals was typically less significant for assimilation organs of B. pendula compared to P. italica. Thus, the content of zinc and lead in the leaves during the study increased only in 2 times towards control. The leaves of B. pendula, unlike P. italica, more intensively accumulated cadmium in the phase of leaf full separation and on 5-10 day of phase finishing point of their growth (it was 6 and 15 times higher relative to control respectively. It was obviously connected to the fact that the surface texture of poplar leaves may cause intense sticking of dust particles containing heavy metals and penetration into the leaves. The effect of heavy metals in both phases of leaf morphogenesis caused an increase in lipid peroxidation by 40-52% for P. italica and almost by 3 times for B. pendula

  9. Evolutionary dynamics of birch (Betula aetnensis Rafin coppices on the Mount Etna (Sicily

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    Bagnato S

    2014-04-01

    Full Text Available Evolutionary dynamics of birch (Betula aetnensis Rafin coppices on the Mount Etna (Sicily. The aim of this paper is to evaluate the dynamics of Etna birch stands (Betula aetnensis Rafin following the cessation of silvicultural activities in the Etna Regional Park (Sicily. We investigated forest structure, natural regeneration, vegetation and deadwood in different forest types. Our findings highlighted three different dynamics for birch populations: stable birch stands in the high mountain area which might represent an edapho-climax forest; progressive dynamic birch stands in the intermediate mountain area, showing a gradual depletion of birch and a concomitant replacement with monospecific stands (calabrian pine, beech, oaks or mixed ones (with birch; pure birch stands (typical that tend to be regressive - especially under stressful conditions - and to be replaced by xerophilous grasslands. Following the cessation of coppicing and with stand ageing, the stumps transformation into more homogeneous stand structures have been increasing. Within the context of protected areas the restoration of coppice selection system (with appropriate adaptations could help to maintain the traditional forest landscape, acting as a silvicultural technique with low environmental and landscape impact.

  10. Effects of solar UV-A and UV-B radiation on gene expression and phenolic accumulation in Betula pendula leaves.

    Science.gov (United States)

    Morales, Luis O; Tegelberg, Riitta; Brosché, Mikael; Keinänen, Markku; Lindfors, Anders; Aphalo, Pedro J

    2010-07-01

    Ultraviolet (UV) radiation is an important environmental factor for plant communities; however, plant responses to solar UV are not fully understood. Here, we report differential effects of solar UV-A and UV-B radiation on the expression of flavonoid pathway genes and phenolic accumulation in leaves of Betula pendula Roth (silver birch) seedlings grown outdoors. Plants were exposed for 30 days to six UV treatments created using three types of plastic film. Epidermal flavonoids measured in vivo decreased when UV-B was excluded. In addition, the concentrations of six flavonoids determined by high-performance liquid chromatography-mass spectrometry declined linearly with UV-B exclusion, and transcripts of PAL and HYH measured by quantitative real-time polymerase chain reaction were expressed at lower levels. UV-A linearly regulated the accumulation of quercetin-3-galactoside and quercetin-3-arabinopyranoside and had a quadratic effect on HYH expression. Furthermore, there were strong positive correlations between PAL expression and accumulation of four flavonols under the UV treatments. Our findings in silver birch contribute to a more detailed understanding of plant responses to solar UV radiation at both molecular and metabolite levels.

  11. Fluctuation of birch (Betula L. pollen seasons in Poland

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    Małgorzata Puc

    2015-12-01

    Full Text Available Birch pollen grains are one of the most important groups of atmospheric biological particles that induce allergic processes. The fluctuation pattern of birch pollen seasons in selected cities of Poland is presented. Measurements were performed by the volumetric method (Burkard and Lanzoni 2000 pollen samplers. The distributions of the data were not normal (Shapiro–Wilk test and statistical error risk was estimated at a significance level of α = 0.05. Pollen season was defined as the period in which 95% of the annual total catch occurred. The linear trend for the selected features of the pollen season, skewness, kurtosis and coefficient of variation (V% were also analyzed. During the 12–14 years of study, the beginnings of birch pollen seasons were observed 7–14 days earlier, the ends were noted 5–10 days earlier, and the days with maximum values occurred 7–14 days earlier compared to the long-term data. The left-skewed distribution of the pollen season starts in most sampling sites confirms the short-lasting occurrence of pollen in the air. The threat of birch pollen allergens was high during the pollen seasons. If vegetation is highly diverse, flowering and pollen release are extended in time, spread over different weeks and occur at different times of the day. Flowering time and pollen release are affected by insolation, convection currents, wind, and turbulence. Therefore, pollen seasons are characterized by great inter-annual variability.

  12. Birch pollen allergy: molecular characterization and hypoallergenic products

    NARCIS (Netherlands)

    Schenk, M.F.

    2008-01-01

    Allergic diseases, such as hay fever and food allergy, affect a substantial part of the population in westernized countries. Pollen of the European white birch (Betula pendula) is a considerable cause of hay fever (seasonal allergic rhinitis) in northern and central Europe. The major birch pollen al

  13. Wood anatomical analysis of Alnus incana and Betula pendula injured by a debris-flow event.

    Science.gov (United States)

    Arbellay, Estelle; Stoffel, Markus; Bollschweiler, Michelle

    2010-10-01

    Vessel chronologies in ring-porous species have been successfully employed in the past to extract the climate signal from tree rings. Environmental signals recorded in vessels of ring-porous species have also been used in previous studies to reconstruct discrete events of drought, flooding and insect defoliation. However, very little is known about the ability of diffuse-porous species to record environmental signals in their xylem cells. Moreover, time series of wood anatomical features have only rarely been used to reconstruct former geomorphic events. This study was therefore undertaken to characterize the wood anatomical response of diffuse-porous Alnus incana (L.) Moench and Betula pendula Roth to debris-flow-induced wounding. Tree microscopic response to wounding was assessed through the analysis of wood anatomical differences between injured rings formed in the debris-flow event year and uninjured rings formed in the previous year. The two ring types were examined close and opposite to the injury in order to determine whether wound effects on xylem cells decrease with increasing tangential distance from the injury. Image analysis was used to measure vessel parameters as well as fiber and parenchyma cell (FPC) parameters. The results of this study indicate that injured rings are characterized by smaller vessels as compared with uninjured rings. By contrast, FPC parameters were not found to significantly differ between injured and uninjured rings. Vessel and FPC parameters mainly remained constant with increasing tangential distance from the injury, except for a higher proportion of vessel lumen area opposite to the injury within A. incana. This study highlights the existence of anatomical tree-ring signatures-in the form of smaller vessels-related to past debris-flow activity and addresses a new methodological approach to date injuries inflicted on trees by geomorphic processes.

  14. Climate change effect on Betula (birch) and Quercus (oak) pollen seasons in the United States

    Science.gov (United States)

    Zhang, Yong; Bielory, Leonard; Georgopoulos, Panos G.

    2014-07-01

    Climatic change is expected to affect the spatiotemporal patterns of airborne allergenic pollen, which has been found to act synergistically with common air pollutants, such as ozone, to cause allergic airway disease (AAD). Observed airborne pollen data from six stations from 1994 to 2011 at Fargo (North Dakota), College Station (Texas), Omaha (Nebraska), Pleasanton (California), Cherry Hill and Newark (New Jersey) in the US were studied to examine climate change effects on trends of annual mean and peak value of daily concentrations, annual production, season start, and season length of Betula (birch) and Quercus (oak) pollen. The growing degree hour (GDH) model was used to establish a relationship between start/end dates and differential temperature sums using observed hourly temperatures from surrounding meteorology stations. Optimum GDH models were then combined with meteorological information from the Weather Research and Forecasting (WRF) model, and land use land coverage data from the Biogenic Emissions Land use Database, version 3.1 (BELD3.1), to simulate start dates and season lengths of birch and oak pollen for both past and future years across the contiguous US (CONUS). For most of the studied stations, comparison of mean pollen indices between the periods of 1994-2000 and 2001-2011 showed that birch and oak trees were observed to flower 1-2 weeks earlier; annual mean and peak value of daily pollen concentrations tended to increase by 13.6 %-248 %. The observed pollen season lengths varied for birch and for oak across the different monitoring stations. Optimum initial date, base temperature, and threshold GDH for start date was found to be 1 March, 8 °C, and 1,879 h, respectively, for birch; 1 March, 5 °C, and 4,760 h, respectively, for oak. Simulation results indicated that responses of birch and oak pollen seasons to climate change are expected to vary for different regions.

  15. Climate change effect on Betula (birch) and Quercus (oak) pollen seasons in the United States.

    Science.gov (United States)

    Zhang, Yong; Bielory, Leonard; Georgopoulos, Panos G

    2014-07-01

    Climatic change is expected to affect the spatiotemporal patterns of airborne allergenic pollen, which has been found to act synergistically with common air pollutants, such as ozone, to cause allergic airway disease (AAD). Observed airborne pollen data from six stations from 1994 to 2011 at Fargo (North Dakota), College Station (Texas), Omaha (Nebraska), Pleasanton (California), Cherry Hill and Newark (New Jersey) in the US were studied to examine climate change effects on trends of annual mean and peak value of daily concentrations, annual production, season start, and season length of Betula (birch) and Quercus (oak) pollen. The growing degree hour (GDH) model was used to establish a relationship between start/end dates and differential temperature sums using observed hourly temperatures from surrounding meteorology stations. Optimum GDH models were then combined with meteorological information from the Weather Research and Forecasting (WRF) model, and land use land coverage data from the Biogenic Emissions Land use Database, version 3.1 (BELD3.1), to simulate start dates and season lengths of birch and oak pollen for both past and future years across the contiguous US (CONUS). For most of the studied stations, comparison of mean pollen indices between the periods of 1994-2000 and 2001-2011 showed that birch and oak trees were observed to flower 1-2 weeks earlier; annual mean and peak value of daily pollen concentrations tended to increase by 13.6%-248%. The observed pollen season lengths varied for birch and for oak across the different monitoring stations. Optimum initial date, base temperature, and threshold GDH for start date was found to be 1 March, 8 °C, and 1,879 h, respectively, for birch; 1 March, 5 °C, and 4,760 h, respectively, for oak. Simulation results indicated that responses of birch and oak pollen seasons to climate change are expected to vary for different regions.

  16. Genome sequence of dwarf birch (Betula nana) and cross-species RAD markers.

    Science.gov (United States)

    Wang, Nian; Thomson, Marian; Bodles, William J A; Crawford, Robert M M; Hunt, Harriet V; Featherstone, Alan Watson; Pellicer, Jaume; Buggs, Richard J A

    2013-06-01

    New sequencing technologies allow development of genome-wide markers for any genus of ecological interest, including plant genera such as Betula (birch) that have previously proved difficult to study due to widespread polyploidy and hybridization. We present a de novo reference genome sequence assembly, from 66× short read coverage, of Betula nana (dwarf birch) - a diploid that is the keystone woody species of subarctic scrub communities but of conservation concern in Britain. We also present 100 bp PstI RAD markers for B. nana and closely related Betula tree species. Assembly of RAD markers in 15 individuals by alignment to the reference B. nana genome yielded 44-86k RAD loci per individual, whereas de novo RAD assembly yielded 64-121k loci per individual. Of the loci assembled by the de novo method, 3k homologous loci were found in all 15 individuals studied, and 35k in 10 or more individuals. Matching of RAD loci to RAD locus catalogues from the B. nana individual used for the reference genome showed similar numbers of matches from both methods of RAD locus assembly but indicated that the de novo RAD assembly method may overassemble some paralogous loci. In 12 individuals hetero-specific to B. nana 37-47k RAD loci matched a catalogue of RAD loci from the B. nana individual used for the reference genome, whereas 44-60k RAD loci aligned to the B. nana reference genome itself. We present a preliminary study of allele sharing among species, demonstrating the utility of the data for introgression studies and for the identification of species-specific alleles.

  17. Identification of SSR loci in Betula luminifera using birch EST data

    Institute of Scientific and Technical Information of China (English)

    LU Yong-quan; LI Hai-ying; JIA Qing; HUANG Hua-hong; TONG Zai-kang

    2011-01-01

    Expressed sequence tags (ESTs) are generated from single-pass sequencing of randomly picked cDNA clones and can be used for development of simple sequence repeat (SSR) markers or microsatellites.However,EST databases have been developed for only a small number of species.This paper provides a case study of the utility of freely available birch EST reources for the development of markers necessary for the genetic analysis of Betula luminifera.Based on birch EST data,primers for 80 EST-SSR candidate loci were developed and tested in birch.Of these,59 EST-SSR loci yielded single,stable and clear PCR products.We then tested the utility of those 59 markers in B.luminifera.The results showed 28 (47.6%) yielded stable and clear PCR products for at least one B.luminifera genotype.In addition,this study describes a rapid and inexpensive alternative for the development of SSRs in species with scarce available sequence data.

  18. Flavonoids in the leaves of polish species of the genus Betula L. L The flavonoids of B. pendula Roth. and B. obscura Kot. leaves

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    Lucyna Pawłowska

    2014-01-01

    Full Text Available Betula pendula Roth. leaves were found to contain, beside the flavonoids detected earlier by other researchers, isorhamnetin 3-galactoside, acacetin 7-glucoside, and perhaps scutellarein 7-glycoside and quercetin 3-glycoside-7,4'-dimethyl ether. The investigated specimens of this species can be divided into two groups on the basis of the presence or absence in them of 6-methoxykaempferide. Group I was characterized by larger leaf-blades containing this compound, whereas it was absent in group II with smaller leaves. The composition of the leaf flavonoids of B. obscura Kot. samples was identical with that of the specimens of the above-mentioned small leaved B. pendula.

  19. Development of SSR Markers and Genetic Diversity in White Birch (Betula platyphylla.

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    Wei Hao

    Full Text Available In order to study genetic diversity of white birch (Betula platyphylla, 544 primer pairs were designed based on the genome-wide Solexa sequences. Among them, 215 primer pairs showed polymorphism between five genotypes and 111 primer pairs that presented clear visible bands in genotyping 41 white birch plants that were collected from 6 different geographical regions. A total of 717 alleles were obtained at 111 loci with a range of 2 to 12 alleles per locus. The results of statistic analysis showed that polymorphic frequency of the alleles ranged from 17% to 100% with a mean of 55.85%; polymorphism information content (PIC of the loci was from 0.09 to 0.58 with a mean of 0.30; and gene diversity between the tested genotypes was from 0.01 to 0.66 with a mean of 0.36. The results also indicated that major allele frequency ranged from 0.39 to 1.00 with an mean of 0.75; expected heterozygosity from 0.22 to 0.54 with a mean of 0.46; observed heterozygosity from 0.02 to 0.95 with a mean of 0.26; Nei's index from 0.21 to 0.54 with a mean of 0.46; and Shannon's Information from 0.26 to 0.87 with a mean of 0.66. The 41 white birch genotypes at the 111 selected SSR loci showed low to moderate similarity (0.025-0.610, indicating complicated genetic diversity among the white birch collections. The UPGMA-based clustering analysis of the allelic constitution of 41 white birch genotypes at 111 SSR loci suggested that the six different geographical regions can be further separated into four clusters at a similarity coefficient of 0.22. Genotypes from Huanren and Liangshui provenances were grouped into Cluster I, genotypes from Xiaobeihu and Qingyuan provenances into Cluster II, genotypes from Finland provenance into Cluster III, and genotypes from Maoershan into Cluster IV. The information provided in this study could help for genetic improvement and germplasm conservation, evaluation and utilization in white birch tree breeding program.

  20. Nickel and Copper Toxicity and Plant Response Mechanisms in White Birch (Betula papyrifera).

    Science.gov (United States)

    Theriault, Gabriel; Nkongolo, Kabwe

    2016-08-01

    Nickel (Ni) and copper (Cu) are the most prevalent metals found in the soils in the Greater Sudbury Region (Canada) because of smelting emissions. The main objectives of the present study were to (1) determine the toxicity of nickel (Ni) and copper (Cu) at different doses in Betula papyrifera (white birch), (2) Characterize nickel resistance mechanism, and (3) assess segregating patterns for Ni and Cu resistance in B. papyrifera populations. This study revealed that B. papyrifera is resistant to Ni and Cu concentrations equivalent to the levels reported in metal-contaminated stands in the GSR. Resistant genotypes (RG) accumulate Ni in roots but not in leaves. Moderately susceptible (MSG) and susceptible genotypes (SG) show a high level of Ni translocation to leaves. Gene expression analysis showed differential regulation of genes in RG compared to MSG and SG. Analysis of segregation patterns suggests that resistance to Ni and Cu is controlled by single recessive genes.

  1. Morphology of Betula pendula var. carelica bark at the pre-reproductive stage

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    Nadezhda N. Nikolaeva

    2014-04-01

    Full Text Available Changes in bark morphology at the pre-reproductive stage of Karelian birch are for the first time considered in connection with the type of trunk surface. The bark surface in Karelian birch changes with age from smooth to fissured. At the pre-reproductive stage Karelian birch has smooth bark with different types of exfoliation of the phellem surface layers, and tubercular specimens feature locally fissured bark on muffs at the very onset of their formation, as well as early rhytidome formation. Morphology of the bark tissues complex is a reflection of direction and intensity of the internal processes of the plant.

  2. Effect of air pollutant NO₂ on Betula pendula, Ostrya carpinifolia and Carpinus betulus pollen fertility and human allergenicity.

    Science.gov (United States)

    Cuinica, Lázaro G; Abreu, Ilda; Esteves da Silva, Joaquim

    2014-03-01

    Pollen of Betula pendula, Ostrya carpinifolia and Carpinus betulus was exposed in vitro to two levels of NO2 (about 0.034 and 0.067 ppm) - both below current atmospheric hour-limit value acceptable for human health protection in Europe (0.11 ppm for NO2). Experiments were performed under artificial solar light with temperature and relative humidity continuously monitored. The viability, germination and total soluble proteins of all the pollen samples exposed to NO2 decreased significantly when compared with the non-exposed. The polypeptide profiles of all the pollen samples showed bands between 15 and 70 kDa and the exposure to NO2 did not produce any detectable changes in these profiles. However, the immunodetection assays indicated higher IgE recognition by patient sera sensitized to the pollen extracts from all exposed samples in comparison to the non-exposed samples. The common reactive bands to the three pollen samples correspond to 58 and 17 kDa proteins.

  3. Effect of birch (Betula spp.) and associated rhizoidal bacteria on the degradation of soil polyaromatic hydrocarbons, PAH-induced changes in birch proteome and bacterial community

    Energy Technology Data Exchange (ETDEWEB)

    Tervahauta, Arja I. [Department of Biosciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio (Finland)], E-mail: arja.tervahauta@uku.fi; Fortelius, Carola [EVTEK University of Applied Sciences, Vantaa (Finland); Tuomainen, Marjo [Department of Biosciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio (Finland); Akerman, Marja-Leena [EVTEK University of Applied Sciences, Vantaa (Finland); Rantalainen, Kimmo [Department of Biosciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio (Finland); Sipilae, Timo [Department of Biological and Environmental Sciences, University of Helsinki (Finland); Lehesranta, Satu J.; Koistinen, Kaisa M.; Kaerenlampi, Sirpa [Department of Biosciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio (Finland); Yrjaelae, Kim [Department of Biological and Environmental Sciences, University of Helsinki (Finland)

    2009-01-15

    Two birch clones originating from metal-contaminated sites were exposed for 3 months to soils (sand-peat ratio 1:1 or 4:1) spiked with a mixture of polyaromatic hydrocarbons (PAHs; anthracene, fluoranthene, phenanthrene, pyrene). PAH degradation differed between the two birch clones and also by the soil type. The statistically most significant elimination (p {<=} 0.01), i.e. 88% of total PAHs, was observed in the more sandy soil planted with birch, the clearest positive effect being found with Betula pubescens clone on phenanthrene. PAHs and soil composition had rather small effects on birch protein complement. Three proteins with clonal differences were identified: ferritin-like protein, auxin-induced protein and peroxidase. Differences in planted and non-planted soils were detected in bacterial communities by 16S rRNA T-RFLP, and the overall bacterial community structures were diverse. Even though both represent complex systems, trees and rhizoidal microbes in combination can provide interesting possibilities for bioremediation of PAH-polluted soils. - Birch can enhance degradation of PAH compounds in the rhizosphere.

  4. Leaf traits and photosynthetic responses of Betula pendula saplings to a range of ground-level ozone concentrations at a range of nitrogen loads.

    Science.gov (United States)

    Harmens, Harry; Hayes, Felicity; Sharps, Katrina; Mills, Gina; Calatayud, Vicent

    2017-04-01

    Ground-level ozone (O3) concentrations and atmospheric nitrogen (N) deposition rates have increased strongly since the 1950s. Rising ground-level O3 concentrations and atmospheric N deposition both affect plant physiology and growth, however, impacts have often been studied in isolation rather than in combination. In addition, studies are often limited to a control treatment and one or two elevated levels of ozone and/or nitrogen supply. In the current study, three-year old Betula pendula saplings were exposed to seven different O3 profiles (24h mean O3 concentration of 36-68ppb in 2013, with peaks up to an average of 105ppb) in precision-controlled hemispherical glasshouses (solardomes) and four different N loads (10, 30, 50 or 70kgNha(-1)y(-1)) in 2012 and 2013. Here we report on the effects of enhanced O3 concentrations and N load on leaf traits and gas exchange in leaves of varying age and developmental stage in 2013. The response of leaf traits to O3 (but not N) vary with leaf developmental stage. For example, elevated O3 did not affect the chlorophyll content of the youngest fully expanded leaf, but it reduced the chlorophyll content and photosynthetic parameters in aging leaves, relatively more so later than earlier in the growing season. Elevated O3 enhanced the N content of senesced leaves prior to leaf fall, potentially affecting subsequent N cycling in the soil. Enhanced N generally stimulated the chlorophyll content and photosynthetic capacity. Whilst elevated O3 reduced the light-saturated rate of photosynthesis (Asat) in aging leaves, it did not affect stomatal conductance (gs). This suggests that photosynthesis and gs are not closely coupled at elevated O3 under-light saturating conditions. We did not observe any interactions between O3 and N regarding photosynthetic parameters (Vc,max, Jmax, Asat), chlorophyll content, gs, N content in senesced leaves and leaf number. Hence, the sensitivity of these leaf traits to O3 in young silver birch trees is

  5. Aluminum uptake and migration from the soil compartment into Betula pendula for two different environments: a polluted and environmentally protected area of Poland.

    Science.gov (United States)

    Frankowski, Marcin

    2016-01-01

    This paper presents the impact of soil contamination on aluminum (Al) concentrations in plant parts of Betula pendula and a possible way of migration and transformation of Al in the soil-root-stem-twig-leaf system. A new procedure of Al fractionation based on extraction in water phase was applied to obtain and measure the most available forms of Al in soils and B. pendula samples. In addition, total Al content was determined in biological samples and pseudo total Al content in soil samples collected under plant saplings, using atomic absorption spectrometry with flame atomization. A number of relations concerning the occurrence of Al and Ca in soils and plant parts of B. pendula (tap roots, lateral roots, stem, twigs, and leaves) were observed. Based on the research findings, the mechanism of Al migration from soil to the leaves of B. pendula can be presented. It was found that aluminum uptake may be limited in roots by high calcium concentration. The application of a new procedure based on the simple sequential extraction of water-soluble fractions (the most available and exchangeable fractions of Al) can be used as an effective tool for the estimation of aluminum toxicity in soils and plants.

  6. Change in ATP-binding cassette B1/19, glutamine synthetase and alcohol dehydrogenase gene expression during root elongation in Betula pendula Roth and Alnus glutinosa L. Gaertn in response to leachate and leonardite humic substances.

    Science.gov (United States)

    Tahiri, Abdelghani; Delporte, Fabienne; Muhovski, Yordan; Ongena, Marc; Thonart, Philippe; Druart, Philippe

    2016-01-01

    Humic substances (HS) are complex and heterogeneous compounds of humified organic matter resulting from the chemical and microbiological decomposition of organic residues. HS have a positive effect on plant growth and development by improving soil structure and fertility. They have long been recognized as plant growth-promoting substances, particularly with regard to influencing nutrient uptake, root growth and architecture. The biochemical and molecular mechanisms through which HS influence plant physiology are not well understood. This study evaluated the bioactivity of landfill leachate and leonardite HS on alder (Alnus glutinosa L. Gaertn) and birch (Betula pendula Roth) during root elongation in vitro. Changes in root development were studied in relation to auxin, carbon and nitrogen metabolisms, as well as to the stress adaptive response. The cDNA fragments of putative genes encoding two ATP-binding cassette (ABC) transporters (ABCB1 and ABCB19) belonging to the B subfamily of plant ABC auxin transporters were cloned and sequenced. Molecular data indicate that HS and their humic acid (HA) fractions induce root growth by influencing polar auxin transport (PAT), as illustrated by the modulation of the ABCB transporter transcript levels (ABCB1 and ABCB19). There were also changes in alcohol dehydrogenase (ADH) and glutamine synthetase (GS) gene transcript levels in response to HS exposure. These findings confirmed that humic matter affects plant growth and development through various metabolic pathways, including hormonal, carbon and nitrogen metabolisms and stress response or signalization.

  7. Seven different genes encode a diverse mixture of isoforms of Bet v 1, the major birch pollen allergen

    NARCIS (Netherlands)

    Schenk, M.F.; Gilissen, L.J.W.J.; Esselink, G.D.; Smulders, M.J.M.

    2006-01-01

    Background: Pollen of the European white birch (Betula pendula, syn. B. verrucosa) is an important cause of hay fever. The main allergen is Bet v 1, member of the pathogenesis-related class 10 (PR-10) multigene family. To establish the number of PR-10/Bet v 1 genes and the isoform diversity within a

  8. REE, Uranium (U) and Thorium (Th) contents in Betula pendula leaf growing around Komsomolsk gold concentration plant tailing (Kemerovo region, Western Siberia, Russia)

    Science.gov (United States)

    Yusupov, D. V.; Karpenko, Yu A.

    2016-09-01

    The article deals with the research findings of peculiarities of REE, Uranium and Thorium distribution in the territory surrounding the tailing of former Komsomolsk gold concentration plant according to the data from Betula pendula leaf testing. In the leaf element composition the slight deficiency of MREE and substantial excess of HREE are presented. In the nearest impacted area around the tailing, La, Yb, U and Th content, and Th/U ratio are lower than in the distant buffer area. It is shown, that value of Th/U ratio and REE can be an indicator for geochemical transformations of technogenic landscapes in mining districts. The results of the research can be used for biomonitoring of the territory around the tailing.

  9. Overexpression of a MADS-box gene from birch (Betula platyphylla promotes flowering and enhances chloroplast development in transgenic tobacco.

    Directory of Open Access Journals (Sweden)

    Guan-Zheng Qu

    Full Text Available In this study, a MADS-box gene (BpMADS, which is an ortholog of AP1 from Arabidopsis, was isolated from birch (Betula platyphylla. Transgenic Arabidopsis containing a BpMADS promoter::GUS construct was produced, which exhibited strong GUS staining in sepal tissues. Ectopic expression of BpMADS significantly enhanced the flowering of tobacco (35S::BpMADS. In addition, the chloroplasts of transgenic tobacco exhibited much higher growth and division rates, as well rates of photosynthesis, than wild-type. A grafting experiment demonstrated that the flowering time of the scion was not affected by stock that overexpressed BpMADS. In addition, the overexpression of BpMADS resulted in the upregulation of some flowering-related genes in tobacco.

  10. Proteomic profiling of birch (Betula verrucosa) pollen extracts from different origins.

    Science.gov (United States)

    Erler, Anja; Hawranek, Thomas; Krückemeier, Leif; Asam, Claudia; Egger, Matthias; Ferreira, Fátima; Briza, Peter

    2011-04-01

    Pollen of the European white birch is a major source of spring pollinosis in Europe. Pollen-allergy diagnosis and treatment by specific immunotherapy commonly rely on extracts of natural origin. To gain insight into the protein content and its variability, we evaluated the profile of allergenic and non-allergenic proteins in extracts of pollen from different origins by MS-based proteomics. Aqueous extracts prepared from commercially available Swedish birch pollen, pollen collected from Austrian trees and a commercial skin prick extract were analyzed by 1-DE, 2-DE, immunoblotting and mass spectrometry, resulting in a complete inventory of extractable, disease-relevant pollen proteins. A main focus of this study was on the isoform distribution of Bet v 1, the major allergen of birch pollen. Using a combination of intact mass determination and peptide sequencing, five isoforms (a, b, d, f and j) were unequivocally identified in Swedish and Austrian birch pollen extracts, while the skin prick extract contained only isoforms a, b and d. Using the same methods as for Bet v 1, divergencies in the sequence of birch profilin (Bet v 2), a plant panallergen, were solved. The molecular characterization of pollen extracts is relevant for standardization and development of new reagents for specific immunotherapy.

  11. Impacts of Elevated Atmospheric CO2 and O3 on Paper Birch (Betula papyrifera: Reproductive Fitness

    Directory of Open Access Journals (Sweden)

    Joseph N. T. Darbah

    2007-01-01

    Full Text Available Atmospheric CO2 and tropospheric O3 are rising in many regions of the world. Little is known about how these two commonly co-occurring gases will affect reproductive fitness of important forest tree species. Here, we report on the long-term effects of CO3 and O3 for paper birch seedlings exposed for nearly their entire life history at the Aspen FACE (Free Air Carbon Dioxide Enrichment site in Rhinelander, WI. Elevated CO2 increased both male and female flower production, while elevated O3 increased female flower production compared to trees in control rings. Interestingly, very little flowering has yet occurred in combined treatment. Elevated CO2 had significant positive effect on birch catkin size, weight, and germination success rate (elevated CO2 increased germination rate of birch by 110% compared to ambient CO2 concentrations, decreased seedling mortality by 73%, increased seed weight by 17%, increased root length by 59%, and root-to-shoot ratio was significantly decreased, all at 3 weeks after germination, while the opposite was true of elevated O3 (elevated O3 decreased the germination rate of birch by 62%, decreased seed weight by 25%, and increased root length by 15%. Under elevated CO2, plant dry mass increased by 9 and 78% at the end of 3 and 14 weeks, respectively. Also, the root and shoot lengths, as well as the biomass of the seedlings, were increased for seeds produced under elevated CO2, while the reverse was true for seedlings from seeds produced under the elevated O3. Similar trends in treatment differences were observed in seed characteristics, germination, and seedling development for seeds collected in both 2004 and 2005. Our results suggest that elevated CO2 and O3 can dramatically affect flowering, seed production, and seed quality of paper birch, affecting reproductive fitness of this species.

  12. Unravelling the distinct crystallinity and thermal properties of suberin compounds from Quercus suber and Betula pendula outer barks.

    Science.gov (United States)

    Sousa, Andreia F; Gandini, Alessandro; Caetano, Ana; Maria, Teresa M R; Freire, Carmen S R; Neto, Carlos Pascoal; Silvestre, Armando J D

    2016-12-01

    The main purpose of this study was to investigate the potential of suberin (a naturally occurring aromatic-aliphatic polyester ubiquitous to the vegetable realm) as a renewable source of chemicals and, in particular, to assess their physical properties. A comparison between cork and birch suberin fragments obtained by conventional depolymerisation processes (hydrolysis or methanolysis) is provided, focusing essentially on their thermal and crystallinity properties. It was found that suberin fragments obtained by the hydrolysis depolymerisation of birch had a high degree of crystallinity, as indicated by their thermal analysis and corroborated by the corresponding XRD diffractions, as opposed to hydrolysis-depolymerised cork suberin counterparts, which were essentially amorphous.

  13. The Effects of Surface Roughness on Adhesion Strength of Coated Ash (Fraxinus excelsior L. and Birch (Betula L. Wood

    Directory of Open Access Journals (Sweden)

    Justina VITOSYTĖ

    2012-12-01

    Full Text Available For the evaluation of surface roughness impact on adhesion properties, the samples of dried ash (Fraxinus excelsior L. and birch (Betula L. wood were used. Before wood finishing, the surfaces of the samples were sanded. In order to get different surface roughness the abrasive material of P80, P120, P150, P180, P220 and P240 grit was used. The parameters of surface roughness Ra, Rz and Rmax were measured in three directions: along the wood grain, across the grain and in the angle of 45º. Comparison of the results showed the non-linear dependency of roughness parameters. Afterwards the wood surface was coated with three different acrylic-polyurethane coating systems (1 layer of varnish without primer, 1 layer of primer and 1 layer of varnish, and 1 layer of primer and 2 layers of varnish. The adhesion strength was assessed using the pull-off method. Also the nature of the fracture was evaluated. It was determined that the peculiarities of surface roughness, coating system type and wood species signally results the values of the adhesion strength.DOI: http://dx.doi.org/10.5755/j01.ms.18.4.3094

  14. Supercritical fluid extraction of amino acids from birch (Betula pendula Roth) leaves and their liquid chromatographic determination with fluorimetric detection.

    Science.gov (United States)

    Klejdus, Borivoj; Lojková, Lea; Kula, Emanuel; Buchta, Ivan; Hrdlicka, Petr; Kubán, Vlastimil

    2008-05-01

    A method for supercritical fluid extraction (SFE) of amino acids was adapted and optimal experimental conditions were selected for a matrix consisting of dry leaves. The matrix-dependent SFE method uses a mixture of MeOH-H(2)O-acetonitrile (10:10:1 v/v/v) as a modifier (0.5 mL in situ, 300 muL on-line) at 70 degrees C and 40 MPa and no HCl is needed as an entrainer. The amino acids were quantified using high-performance liquid chromatography with fluorimetric detection (HPLC/FLD) after gradient elution on Zorbax Eclipse AAA columns (4.6x150 mm, 3.5 mum) with aqueous Na(2)HPO(4 )buffer of pH 7.8 and ACN-MeOH-water as a mobile phase. In comparison with Soxhlet extraction, SFE gave higher recovery and selectivity, but it required longer extraction time (90 min) and it was more labor-intensive (clean-up step after the pre-concentration). Both methods should be used separately or in combination according to the matrix, number of samples, and levels of ballast compounds.

  15. N2 fixation and cycling in Alnus glutinosa, Betula pendula and Fagus sylvatica woodland exposed to free air CO2 enrichment.

    Science.gov (United States)

    Millett, Jonathan; Godbold, Douglas; Smith, Andrew R; Grant, Helen

    2012-06-01

    We measured the effect of elevated atmospheric CO(2) on atmospheric nitrogen (N(2)) fixation in the tree species Alnus glutinosa growing in monoculture or in mixture with the non-N(2)-fixing tree species Betula pendula and Fagus sylvatica. We addressed the hypotheses that (1) N(2) fixation in A. glutinosa will increase in response to increased atmospheric CO(2) concentrations, when growing in monoculture, (2) the impact of elevated CO(2) on N(2) fixation in A. glutinosa is the same in mixture and in monoculture and (3) the impacts of elevated CO(2) on N cycling will be evident by a decrease in leaf δ(15)N and by the soil-leaf enrichment factor (EF), and that these impacts will not differ between mixed and single species stands. Trees were grown in a forest plantation on former agricultural fields for four growing seasons, after which the trees were on average 3.8 m tall and canopy closure had occurred. Atmospheric CO(2) concentrations were maintained at either ambient or elevated (by 200 ppm) concentrations using a free-air CO(2) enrichment (FACE) system. Leaf δ(15)N was measured and used to estimate the amount (N(dfa)) and proportion (%N(dfa)) of N derived from atmospheric fixation. On average, 62% of the N in A. glutinosa leaves was from fixation. The %N(dfa) and N(dfa) for A. glutinosa trees in monoculture did not increase under elevated CO(2), despite higher growth rates. However, N(2) fixation did increase for trees growing in mixture, despite the absence of significant growth stimulation. There was evidence that fixed N(2) was transferred from A. glutinosa to F. sylvatica and B. pendula, but no evidence that this affected their CO(2) response. The results of this study show that N(2) fixation in A. glutinosa may be higher in a future elevated CO(2) world, but that this effect will only occur where the trees are growing in mixed species stands.

  16. Birch (Betula spp.) wood biochar is a potential soil amendment to reduce glyphosate leaching in agricultural soils.

    Science.gov (United States)

    Hagner, Marleena; Hallman, Sanna; Jauhiainen, Lauri; Kemppainen, Riitta; Rämö, Sari; Tiilikkala, Kari; Setälä, Heikki

    2015-12-01

    Glyphosate (N-(phosphonomethyl) glycine), a commonly used herbicide in agriculture can leach to deeper soil layers and settle in surface- and ground waters. To mitigate the leaching of pesticides and nutrients, biochar has been suggested as a potential soil amendment due to its ability to sorb both organic and inorganic substances. However, the efficiency of biochar in retaining agro-chemicals in the soil is likely to vary with feedstock material and pyrolysis conditions. A greenhouse pot experiment, mimicking a crop rotation cycle of three plant genera, was established to study the effects of pyrolysis temperature on the ability of birch (Betula sp.) wood originated biochar to reduce the leaching of (i) glyphosate, (ii) its primary degradation product AMPA and (iii) phosphorus from the soil. The biochar types used were produced at three different temperatures: 300 °C (BC300), 375 °C (BC375) and 475 °C (BC475). Compared to the control treatment without biochar, the leaching of glyphosate was reduced by 81%, 74% and 58% in BC300, BC375 and BC475 treated soils, respectively. The respective values for AMPA were 46%, 39% and 23%. Biochar had no significant effect on the retention of water-soluble phosphorus in the soil. Our results corroborate earlier findings on pesticides, suggesting that biochar amendment to the soil is a promising way to reduce also the leaching of glyphosate. Importantly, the ability of biochar to adsorb agro-chemicals depends on the temperature at which feedstock is pyrolysed.

  17. Contrasting short-term performance of mountain birch (Betula pubescens ssp. czerepanovii) treeline along a latitudinal continentality-maritimity gradient in the southern Swedish Scandes

    OpenAIRE

    2012-01-01

    Positional treeline shift is a fundamental aspect and indicator of high-mountain vegetation response to climate change. This study analyses treeline performance during the period 2005/2007 -2010/2011 in the Swedish Scandes. Focus is on mountain birch (Betula pubescens ssp. czerepanovii) along a regional climatic maritimity-continentality gradient. Treeline upshift by 3.0 yr-1 in the maritime part differed significantly from retreat by 0.4 m yr-1 in the continental part of the transect. This d...

  18. Contrasting short-term performance of mountain birch (Betula pubescens ssp. czerepanovii treeline along a latitudinal continentality-maritimity gradient in the southern Swedish Scandes

    Directory of Open Access Journals (Sweden)

    Lisa Öberg

    2012-01-01

    Full Text Available Positional treeline shift is a fundamental aspect and indicator of high-mountain vegetation response to climate change. This study analyses treeline performance during the period 2005/2007 -2010/2011 in the Swedish Scandes. Focus is on mountain birch (Betula pubescens ssp. czerepanovii along a regional climatic maritimity-continentality gradient. Treeline upshift by 3.0 yr-1 in the maritime part differed significantly from retreat by 0.4 m yr-1 in the continental part of the transect. This discrepancy is discussed in terms of differential warming-induced snow cover phenology patterns and their influence on soil moisture conditions. In the continental area, earlier and more complete melting of prior relatively rare late-lying snow patches, even high above the treeline, has progressed to a state when melt water irrigation ceases. As a consequence, soil drought sets back the vigor of existing birches and precludes sexual regeneration and upslope advance of the treeline. In the maritime area, extensive and deep snow packs still exist above the treeline and constrain its position, although some release is taking place in the current warm climate. Thereby, the birch treeline expands upslope as the alpine snow patches shrink, but continue to provide sufficient melt water throughout the summer. Treeline rise appears to have been based primarily on seed regeneration over the past few decades. This is a novelty, since prior (1915-2007 treeline advance was accomplished mainly by in situ shifts in growth form of relict krummholz birches, in some cases millennial-old, prevailing above the treeline. By the snow phenology mechanism, birch can benefit from climate warming in the maritime region, which contrasts with the situation in the continental region. This discrepancy should be accounted for in projective models. In a hypothetical case of sustained warming, the subalpine birch forest belt may expand less extensively than often assumed, although advance may

  19. Ecological role of reindeer summer browsing in the mountain birch (Betula pubescens ssp. czerepanovii) forests: effects on plant defense, litter decomposition, and soil nutrient cycling.

    Science.gov (United States)

    Stark, Sari; Julkunen-Tiitto, Riitta; Kumpula, Jouko

    2007-03-01

    Mammalian herbivores commonly alter the concentrations of secondary compounds in plants and, by this mechanism, have indirect effects on litter decomposition and soil carbon and nutrient cycling. In northernmost Fennoscandia, the subarctic mountain birch (Betula pubescens ssp. czerepanovii) forests are important pasture for the semidomestic reindeer (Rangifer tarandus). In the summer ranges, mountain birches are intensively browsed, whereas in the winter ranges, reindeer feed on ground lichens, and the mountain birches remain intact. We analyzed the effect of summer browsing on the concentrations of secondary substances, litter decomposition, and soil nutrient pools in areas that had been separated as summer or winter ranges for at least 20 years, and we predicted that summer browsing may reduce levels of secondary compounds in the mountain birch and, by this mechanism, have an indirect effect on the decomposition of mountain birch leaf litter and soil nutrient cycling. The effect of browsing on the concentration of secondary substances in the mountain birch leaves varied between different years and management districts, but in some cases, the concentration of condensed tannins was lower in the summer than in the winter ranges. In a reciprocal litter decomposition trial, both litter origin and emplacement significantly affected the litter decomposition rate. Decomposition rates were faster for the litter originating from and placed into the summer range. Soil inorganic nitrogen (N) concentrations were higher in the summer than in the winter ranges, which indicates that reindeer summer browsing may enhance the soil nutrient cycling. There was a tight inverse relationship between soil N and foliar tannin concentrations in the winter range but not in the summer range. This suggests that in these strongly nutrient-limited ecosystems, soil N availability regulates the patterns of resource allocation to condensed tannins in the absence but not in the presence of browsing.

  20. Protein-lipid composition of silver birch (Betula verrucosa pollen and its antioxidant activity depending on habitat

    Directory of Open Access Journals (Sweden)

    T. Shevtsova

    2013-12-01

    Full Text Available Pollen has various effects on the human body. In order to study and compare the biological activity of the mature pollen grains of Betula verrucosa Ehrh. we investigated the protein-lipid composition and total antioxidant activity (TAA of 10 samples from different habitats in the territory of Ukraine and the Slovak Republic. The collection sites are near highways and apartment blocks, as well as a nature reserve, forest and botanical garden. The protein content was determined by the Kjeldahl method. A chromatographic analysis of fatty acids from lipids was performed using a “Cvet 500” gas chromatograph, equipped with a flame-ionization detector in the isothermal mode. The bioactivity of aqueous, ethanol and methanol extracts of pollen grains was evaluated by the DPPH free radical scavenging method (2,2-diphenyl-1-picrylhydrazyl by means spectrophotometry in vitro. The protein content of the pollen of B. verrucosa ranged from 17.9% to 25.6%, depending on the habitat. Unsaturated fatty acids were found in higher amounts than saturated fatty acids. The profile of fatty acids indicates a higher content of palmitic (33.9%, oleic (29.5% and linoleic (27.8% acids and a low content of arachidonic (0.4% and pentadecanoic (0.8% acids. We also established that silver birch pollen is characterized by high antioxidant activity. The measured value of TAA for aqueous pollen extracts was within 74.8–85.5%. For the ethanol extracts it was quantified within 60.3–95.0% and for the methanol extracts – 46.1–92.6%. The Tukey test was used to determine the differences between the means at a level of P < 0.05. A strong correlation coefficient (0.70 was defined between the protein content and the TAA of aqueous extracts. In general, the Ukrainian and Slovak samples of pollen differ in the fatty acid composition of lipids and aqueous and ethanol TAA extracts. Pollen of B. verrucosa should be used for diagnostic, therapeutic and prophylactic purposes as close

  1. Processing of pine (Pinus sylvestris and birch (Betula pubescens leaf material in a small river system in the northern Cairngorms, Scotland

    Directory of Open Access Journals (Sweden)

    P. Collen

    2004-01-01

    Full Text Available Processing rates, and macroinvertebrate colonisation, of pine needles and birch leaves were studied at eight sites on the river Nethy, a small river system in the Cairngorm region of north-eastern Scotland. Throughout this river system, processing rates were slow for pine (k values 0.0015-0.0034 day-1 and medium to fast for birch (k values 0.0085-0.0331 day-1. Plecopteran shredders dominated both pine and birch leaf packs during the early part of the experiment while chironomids were more important in the latter stages. It is suggested that the slow processing rate of pine needles could adversely affect the productivity of streams, particularly where needles provide the major allochthonous energy source and retentive features are limited. Forest managers should consider this when creating new pinewoods in treeless areas as it will take many years for the trees to reach a size at which they can effectively contribute retentive features, in the form of woody debris, to streams. Keywords: leaf processing, pine needles, shredders, Pinus sylvestris, Betula pubescens, Scotland.

  2. Effects of decadal exposure to interacting elevated CO{sub 2} and/or O{sub 3} on paper birch (Betula papyrifera) reproduction

    Energy Technology Data Exchange (ETDEWEB)

    Darbah, Joseph N.T. [Michigan Technological University, Houghton, MI (United States)], E-mail: jndarbah@mtu.edu; Kubiske, Mark E.; Nelson, Neil [USDA Forest Service, Northern Research Station, Rhinelander, WI (United States); Oksanen, Elina [University of Joensuu, Kuopio (Finland); Vapaavuori, Elina [Finnish Forest Research Institute, Suonenjoki (Finland); Karnosky, David F. [Michigan Technological University, Houghton, MI (United States)

    2008-10-15

    We studied the effects of long-term exposure (nine years) of birch (Betula papyrifera) trees to elevated CO{sub 2} and/or O{sub 3} on reproduction and seedling development at the Aspen FACE (Free-Air Carbon Dioxide Enrichment) site in Rhinelander, WI. We found that elevated CO{sub 2} increased both the number of trees that flowered and the quantity of flowers (260% increase in male flower production), increased seed weight, germination rate, and seedling vigor. Elevated O{sub 3} also increased flowering but decreased seed weight and germination rate. In the combination treatment (elevated CO{sub 2} + O{sub 3}) seed weight is decreased (20% reduction) while germination rate was unaffected. The evidence from this study indicates that elevated CO{sub 2} may have a largely positive impact on forest tree reproduction and regeneration while elevated O{sub 3} will likely have a negative impact. - In this study, we found that elevated CO{sub 2} enhances and elevated O{sub 3} decreases birch reproduction and early seedling growth.

  3. Gene expression responses of paper birch (Betula papyrifera) to elevated CO{sub 2} and O{sub 3} during leaf maturation and senescence

    Energy Technology Data Exchange (ETDEWEB)

    Kontunen-Soppela, Sari, E-mail: sari.kontunen-soppela@joensuu.f [Finnish Forest Research Institute, Suonenjoki Unit, Juntintie 154, FI-77600 Suonenjoki (Finland); University of Joensuu, Faculty of Biosciences, FI-80101 Joensuu (Finland); Parviainen, Juha [University of Kuopio, Department of Environmental Sciences, FI-70211 Kuopio (Finland); Ruhanen, Hanna [Finnish Forest Research Institute, Suonenjoki Unit, Juntintie 154, FI-77600 Suonenjoki (Finland); Brosche, Mikael [University of Helsinki, Faculty of Biosciences, Department of Biological and Environmental Sciences, FI-00014 Helsinki (Finland); Keinaenen, Markku [University of Joensuu, Faculty of Biosciences, FI-80101 Joensuu (Finland); Thakur, Ramesh C. [School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931 (United States); Kolehmainen, Mikko [University of Kuopio, Department of Environmental Sciences, FI-70211 Kuopio (Finland); Kangasjaervi, Jaakko [University of Helsinki, Faculty of Biosciences, Department of Biological and Environmental Sciences, FI-00014 Helsinki (Finland); Oksanen, Elina [University of Joensuu, Faculty of Biosciences, FI-80101 Joensuu (Finland); Karnosky, David F. [School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931 (United States); Vapaavuori, Elina [Finnish Forest Research Institute, Suonenjoki Unit, Juntintie 154, FI-77600 Suonenjoki (Finland)

    2010-04-15

    Gene expression responses of paper birch (Betula papyrifera) leaves to elevated concentrations of CO{sub 2} and O{sub 3} were studied with microarray analyses from three time points during the summer of 2004 at Aspen FACE. Microarray data were analyzed with clustering techniques, self-organizing maps, K-means clustering and Sammon's mappings, to detect similar gene expression patterns within sampling times and treatments. Most of the alterations in gene expression were caused by O{sub 3}, alone or in combination with CO{sub 2}. O{sub 3} induced defensive reactions to oxidative stress and earlier leaf senescence, seen as decreased expression of photosynthesis- and carbon fixation-related genes, and increased expression of senescence-associated genes. The effects of elevated CO{sub 2} reflected surplus of carbon that was directed to synthesis of secondary compounds. The combined CO{sub 2} + O{sub 3} treatment resulted in differential gene expression than with individual gas treatments or in changes similar to O{sub 3} treatment, indicating that CO{sub 2} cannot totally alleviate the harmful effects of O{sub 3}. - Clustering analysis of birch leaf gene expression data reveals differential responses to O{sub 3} and CO{sub 2}.

  4. Analysis of three types of triterpenoids in tetraploid white birches (Betula platyphylla Suk.) and selection of plus trees

    Institute of Scientific and Technical Information of China (English)

    Sui Wang; Hui Zhao; Jing Jiang; Guifeng Liu; Chuanping Yang

    2015-01-01

    Betulin, oleanolic acid, and betulinic acid are naturally occurring pentacyclic triterpenoids that have significant medicinal value. Considerable amounts of these triterpenoids are available in the outer bark of white birch. In this study, we used ultrasound-assisted extraction (UAE) to extract triterpenoids from birch bark rapidly and with high efficiency. Using high performance liquid chro-matography (HPLC), three types of triterpenoids were separated and detected. We examined the differences among triterpenoids extracted from diploid versus tetra-ploid white birch. Then, we used factor analysis to screen out tetraploid white birches with comprehensively excel-lent performance. The results indicate that the optimum conditions for extraction include the use of ethanol as an extraction solvent, a solid-to-liquid ratio of 0.1 g/10 ml, ultrasonic power set at 100 W, a temperature of 60 ?C and an extraction time of 15 min. A reversed-phase C18 col-umn (4.6 mm 9 250 mm 9 5 lm) with a column tem-perature of 30 ?C and the mobile phase composed of A (acetonitrile) and B (0.1% aqueous phosphoric acid, v/v) at a flow rate of 0.5 ml/min were used, and the detection wavelength was 195 nm. No significant difference was observed between diploid and tetraploid white birch in terms of the content of three types of triterpenoids (at a confidence level of 0.05). As triterpenoid content, height, and DBH (diameter at breast height) are strongly interre-lated, we used factor analysis to evaluate all individuals, and we screened out six plus trees with excellent com-prehensive characters.

  5. Recent invasion of the mountain birch Betula pubescens ssp. tortuosa above the treeline due to climate change: genetic and ecological study in northern Sweden

    OpenAIRE

    Truong, C.; Palmé, A. E.; Felber, François

    2008-01-01

    Mountain birch, Betula pubescens ssp. tortuosa, forms the treeline in northern Sweden. A recent shift in the range of the species associated with an elevation of the treeline is commonly attributed to climate warming. Using microsatellite markers, we explored the genetic structure of populations along an altitudinal gradient close to the treeline. Low genetic differentiation was found between populations, whereas high genetic diversity was maintained within populations. High level of gene flo...

  6. Birch Stands Growth Increase in Western Siberia

    Science.gov (United States)

    Kharuk, Viacheslav I.; Kuzmichev, Valeriy V.; Im, Sergey T.; Ranson, Kenneth J.

    2014-01-01

    Birch (Betula pendula Roth) growth within the Western Siberia forest-steppe was analyzed based on long-term (1897-2006) inventory data (height, diameter at breast height [dbh], and stand volume). Analysis of biometry parameters showed increased growth at the beginning of twenty-first century compared to similar stands (stands age = 40-60 years) at the end of nineteenth century. Mean height, dbh, and stem volume increased from 14 to 20 m, from 16 to 22 cm, and from approx. 63 to approx. 220 cu m/ha, respectively. Significant correlations were found between the stands mean height, dbh, and volume on the one hand, and vegetation period length (r(sub s) = 0.71 to 0.74), atmospheric CO2 concentration (r(sub s) = 0.71 to 0.76), and drought index (Standardized Precipitation-Evapotranspiration Index, r(sub s) = -0.33 to -0.51) on the other hand. The results obtained have revealed apparent climate-induced impacts (e.g. increase of vegetation period length and birch habitat drying due to drought increase) on the stands growth. Along with this, a high correlation of birch biometric parameters and [CO2] in ambient air indicated an effect of CO2 fertilization. Meanwhile, further drought increase may switch birch stand growth into decline and greater mortality as has already been observed within the Trans-Baikal forest-steppe ecotone.

  7. Four novel cellulose synthase (CESA) genes from Birch (Betula platyphylla Suk.) involved in primary and secondary cell Wall biosynthesis.

    Science.gov (United States)

    Liu, Xuemei; Wang, Qiuyu; Chen, Pengfei; Song, Funan; Guan, Minxiao; Jin, Lihua; Wang, Yucheng; Yang, Chuanping

    2012-09-25

    Cellulose synthase (CESA), which is an essential catalyst for the generation of plant cell wall biomass, is mainly encoded by the CesA gene family that contains ten or more members. In this study; four full-length cDNAs encoding CESA were isolated from Betula platyphylla Suk., which is an important timber species, using RT-PCR combined with the RACE method and were named as BplCesA3, -4, -7 and -8. These deduced CESAs contained the same typical domains and regions as their Arabidopsis homologs. The cDNA lengths differed among these four genes, as did the locations of the various protein domains inferred from the deduced amino acid sequences, which shared amino acid sequence identities ranging from only 63.8% to 70.5%. Real-time RT-PCR showed that all four BplCesAs were expressed at different levels in diverse tissues. Results indicated that BplCESA8 might be involved in secondary cell wall biosynthesis and floral development. BplCESA3 appeared in a unique expression pattern and was possibly involved in primary cell wall biosynthesis and seed development; it might also be related to the homogalacturonan synthesis. BplCESA7 and BplCESA4 may be related to the formation of a cellulose synthase complex and participate mainly in secondary cell wall biosynthesis. The extremely low expression abundance of the four BplCESAs in mature pollen suggested very little involvement of them in mature pollen formation in Betula. The distinct expression pattern of the four BplCesAs suggested they might participate in developments of various tissues and that they are possibly controlled by distinct mechanisms in Betula.

  8. Recent invasion of the mountain birch Betula pubescens ssp. tortuosa above the treeline due to climate change: genetic and ecological study in northern Sweden.

    Science.gov (United States)

    Truong, C; Palmé, A E; Felber, F

    2007-01-01

    Mountain birch, Betula pubescens ssp. tortuosa, forms the treeline in northern Sweden. A recent shift in the range of the species associated with an elevation of the treeline is commonly attributed to climate warming. Using microsatellite markers, we explored the genetic structure of populations along an altitudinal gradient close to the treeline. Low genetic differentiation was found between populations, whereas high genetic diversity was maintained within populations. High level of gene flow compensated for possible losses of genetic diversity at higher elevations and dissipated the founding effect of newly established populations above the treeline. Spatial autocorrelation analysis showed low spatial genetic structure within populations because of extensive gene flow. At the treeline, significant genetic structure within the juvenile age class at small distances did not persist in the adult age class, indicating recent expansion of young recruits due to the warming of the climate. Finally, seedling performance above the treeline was positively correlated with parameters related to temperature. These data confirm the high migration potential of the species in response to fluctuating environmental conditions and indicate that it is now invading higher altitudes due to the recent warming of the climate.

  9. A Preliminary Pharmacokinetic Study of Betulin, the Main Pentacyclic Triterpene from Extract of Outer Bark of Birch (Betulae alba cortex

    Directory of Open Access Journals (Sweden)

    Melanie N. Laszczyk

    2008-12-01

    Full Text Available During the last two decades triterpenes have attracted attention because of their pharmacological potential. Triterpene extract (TE from outer bark of birch consisting mainly of betulin is able to form an oleogel which was successfully tested in the treatment of actinic keratosis. Some aspects of TE in vitro pharmacology are already known. Now we show preliminary pharmacokinetics of betulin and results of a subchronic toxicity study of TE in rats and dogs. Because of poor aqueous solubility of the TE-triterpenes (< 0.1 μg/mL respectively, for pharmacokinetic studies it was suspended in sesame oil (rats, i.p. and PEG 400 / 0.9 % NaCl (dogs, s.c.. I.p. administered, betulin, the main component of TE, shows time dependency over a period of 4 h and reaches a dose-independent serum level of 0.13 μg/mL. Dose dependency was observed with s.c. administration. At 300 mg/kg a maximum plasma concentration of 0.33 μg/mL betulin was detected after 28 daily applications. The subchronic toxicity study showed no toxicity of TE in rats (i.p. and dogs (s.c.. In conclusion, triterpene extract from birch bark is safe, its betulin is bioavailable and in addition to published triterpene biological activities TE provides high potential for further pharmaceutical and pharmacological research.

  10. How does solar ultraviolet-B radiation improve drought tolerance of silver birch (Betula pendula Roth.) seedlings?

    Science.gov (United States)

    Robson, T Matthew; Hartikainen, Saara M; Aphalo, Pedro J

    2015-05-01

    We hypothesized that solar ultraviolet (UV) radiation would protect silver birch seedlings from the detrimental effects of water stress through a coordinated suite of trait responses, including morphological acclimation, improved control of water loss through gas exchange and hydraulic sufficiency. To better understand how this synergetic interaction works, plants were grown in an experiment under nine treatment combinations attenuating ultraviolet-A and ultraviolet-B (UVB) from solar radiation together with differential watering to create water-deficit conditions. In seedlings under water deficit, UV attenuation reduced height growth, leaf production and leaf length compared with seedlings receiving the full spectrum of solar radiation, whereas the growth and morphology of well-watered seedlings was largely unaffected by UV attenuation. There was an interactive effect of the treatment combination on water relations, which was more apparent as a change in the water potential at which leaves wilted or plants died than through differences in gas exchange. This suggests that changes occur in the cell wall elastic modulus or accumulation of osmolites in cells under UVB. Overall, the strong negative effects of water deficit are partially ameliorated by solar UV radiation, whereas well-watered silver birch seedlings are slightly disadvantaged by the solar UV radiation they receive.

  11. Simultaneous determination of inorganic and organic ions in plant parts of Betula pendula from two different types of ecosystems (Wielkopolski National Park and Chemical Plant in Luboń, Poland).

    Science.gov (United States)

    Frankowski, Marcin

    2016-06-01

    The results of inorganic and organic anion concentrations in samples of soils and plant parts of Betula pendula (tap roots, lateral roots, stem, twigs, leaves), in the bioavailable fraction, are presented in this study. An ion chromatography method was applied for the first time in the simultaneous determination of inorganic and organic anions, as an effective tool for qualitative and quantitative analysis of samples with different matrix. A linear gradient elution with potassium hydroxide allowed for the separation of both inorganic and organic ions such as: F(-), CH3COO(-), HCOO(-), Cl(-), NO2 (-), Br(-) and NO3 (-), SO4 (2-), CH2(COO)2 (2-), C2O4 (2-), PO4 (3-) and C3H5O(COO)3 (3-). The samples of soils and plant parts of B. pendula from the area of the Wielkopolski National Park (WNP) and the Chemical Plant in Luboń (LU; protected vs. contaminated area) were selected for the study. The obtained results indicated that such inorganic ions as: F(-), Cl(-), NO3 (-) and PO4 (3-) are quite easily transported from soil to leaves. In contrast, the mechanism of migration could not be clearly defined for SO4 (2-) because the ion was retained in roots of many of the analysed samples. Significantly higher bioavailability of inorganic ions was observed for samples collected from the area of the WNP. Phosphates were the only ions which showed no variation in their concentrations between the two sampling sites, both for soils and plant parts of B. pendula. None of the organic anions was detected in soil samples. The acetate, formate, malonate, oxalate and citrate ions were detected in all leaf samples. The statistical analysis allowed the author to determine the mechanism of ion migration and accumulation in leaves and, additionally, determine the variation in the occurrence of inorganic and organic ions depending on the sampling site (WNP vs. LU). The results of the statistical analysis were confirmed by the bioacumulation (BF) and translocation (TF) factors.

  12. Phenolic compounds in ectomycorrhizal interaction of lignin modified silver birch

    Directory of Open Access Journals (Sweden)

    Chiang Vincent L

    2009-09-01

    Full Text Available Abstract Background The monolignol biosynthetic pathway interconnects with the biosynthesis of other secondary phenolic metabolites, such as cinnamic acid derivatives, flavonoids and condensed tannins. The objective of this study is to evaluate whether genetic modification of the monolignol pathway in silver birch (Betula pendula Roth. would alter the metabolism of these phenolic compounds and how such alterations, if exist, would affect the ectomycorrhizal symbiosis. Results Silver birch lines expressing quaking aspen (Populus tremuloides L. caffeate/5-hydroxyferulate O-methyltransferase (PtCOMT under the 35S cauliflower mosaic virus (CaMV promoter showed a reduction in the relative expression of a putative silver birch COMT (BpCOMT gene and, consequently, a decrease in the lignin syringyl/guaiacyl composition ratio. Alterations were also detected in concentrations of certain phenolic compounds. All PtCOMT silver birch lines produced normal ectomycorrhizas with the ectomycorrhizal fungus Paxillus involutus (Batsch: Fr., and the formation of symbiosis enhanced the growth of the transgenic plants. Conclusion The down-regulation of BpCOMT in the 35S-PtCOMT lines caused a reduction in the syringyl/guaiacyl ratio of lignin, but no significant effect was seen in the composition or quantity of phenolic compounds that would have been caused by the expression of PtCOMT under the 35S or UbB1 promoter. Moreover, the detected alterations in the composition of lignin and secondary phenolic compounds had no effect on the interaction between silver birch and P. involutus.

  13. Comparison of throughfall and soil solution chemistry between a high-density Corsican pine stand and a naturally regenerated silver birch stand.

    Science.gov (United States)

    De Schrijver, A; Nachtergale, L; Staelens, J; Luyssaert, S; De Keersmaeker, L

    2004-09-01

    In Flanders, critical loads for acidification and eutrophication are exceeded in the majority of the forest stands, and many previously nitrogen limited forest ecosystems have become nitrogen saturated. The present study investigates whether a naturally regenerated stand of silver birch (Betula pendula Roth) contributes less to the acidification and eutrophication of the forest soil than a high-density plantation of Corsican pine (Pinus nigra ssp. laricio Maire). Throughfall deposition of inorganic nitrogen was about 3.5 times higher in the Corsican pine stand than in the birch stand. Potassium throughfall deposition was significantly higher under birch due to higher canopy leaching. Magnesium throughfall deposition was significantly higher under the pine canopy due to higher dry deposition. The lower nitrogen throughfall deposition in the birch stand was reflected in a 60% lower nitrate percolation at 1m depth compared with pine. Nitrate soil percolation is linked to losses of aluminium and base cations.

  14. A Novel R2R3-MYB Transcription Factor BpMYB106 of Birch (Betula platyphylla) Confers Increased Photosynthesis and Growth Rate through Up-regulating Photosynthetic Gene Expression.

    Science.gov (United States)

    Zhou, Chenguang; Li, Chenghao

    2016-01-01

    We isolated a R2R3-MYB transcription factor BpMYB106, which regulates photosynthesis in birch (Betula platyphylla Suk.). BpMYB106 mainly expresses in the leaf and shoot tip of birch, and its protein is localized in the nucleus. We further fused isolated a 1588 bp promoter of BpMYB106 and analyzed it by PLACE, which showed some cis-acting elements related to photosynthesis. BpMYB106 promoter β-glucuronidase (GUS) reporter fusion studies gene, the result, showed the GUS reporter gene in transgenic birch with BpMYB106 promoter showed strong activities in shoot tip, cotyledon margins, and mature leaf trichomes. The overexpression of BpMYB106 in birch resulted in significantly increased trichome density, net photosynthetic rate, and growth rate as compared with the wild-type birch. RNA-Seq profiling revealed the upregulation of several photosynthesis-related genes in the photosynthesis and oxidative phosphorylation pathways in the leaves of transgenic plants. Yeast one-hybrid analysis, coupled with transient assay in tobacco, revealed that BpMYB106 binds a MYB binding site MYB2 in differentially expressed gene promoters. Thus, BpMYB106 may directly activate the expression of a range of photosynthesis related genes through interacting with the MYB2 element in their promoters. Our study demonstrating the overexpression of BpMYB106-a R2R3-MYB transcription factor-upregulates the genes of the photosynthesis and oxidative phosphorylation pathways to improve photosynthesis.

  15. Seasonal dynamics of saproxylic beetles (Coleoptera occurring in decaying birch (Betula spp. wood in the Kampinos National Park

    Directory of Open Access Journals (Sweden)

    Sawoniewicz Michał

    2015-09-01

    Full Text Available The aim of the study was to identify the seasonal changes in the number of saproxylic beetles connected with birch in the Kampinos National Park. The research was conducted for 12 consecutive months in research areas representing 10 different site types. The beetles were collected from wood using photoeclectors. The largest number of species was collected in April and the lowest in January. An increase in number occurred during spring and summer months for species associated only with rotting wood, fructifications of tree fungi, the subcortical environment and hollows. In the same period the number of species not associated or potentially associated with decaying trees and wood decreased. During winter months, the differences in the number of trapped specimens were the smallest. The proportion of zoophagous species amongst the collected specimen increased in autumn and winter. The share of saprophagous species was the highest during the summer-autumn period and the share of mycetophages (jointly with myxomycophages was the highest during spring and summer. We distinguished two separate groups of Coleoptera with the first one (‘summer group’ including species trapped during late-spring and summer months, while the second one (‘winter group’ includes species found in autumn, winter and early-spring months. In the ‘summer group’, an average of 55.8 species was trapped each month with 331.2 specimen of Coleoptera, while in the ʻwinter group’ an average of 56.1 species with 228.4 Coleoptera specimen were caught.

  16. Breeding increases the efficacy of Chondrostereum purpureum in the sprout control of birch.

    Directory of Open Access Journals (Sweden)

    Leena Hamberg

    Full Text Available We tested whether the pairing of selected isolates could be used to increase the efficiency of a decay fungus Chondrostereum purpureum (Pers. Ex Fr. Pouzar to control hardwood sprouting in Finland. We paired C. purpureum strains efficient in sprout control or highly active in laccase production, and tested the efficacy of their progeny in spout control experiments. This procedure resulted in a strain with an efficacy superior to that of the parental strains. The mortality of birch (Betula pendula Roth. and B. pubescens Ehrh. 1 cm in stump diameter was 78%, 56% and 9% for the best progeny, the best parental strain and the control, respectively. Mortality was only slightly higher for B. pendula than for B. pubescens but no significant differences were found between the number or maximum height of stump sprouts. Our results showed that cross breeding of this decay fungus is a good alternative in attempts to produce efficient biocontrol agents against hardwood sprouting.

  17. Influence of Nitrogen Availability on Growth of Two Transgenic Birch Species Carrying the Pine GS1a Gene

    Directory of Open Access Journals (Sweden)

    Vadim G. Lebedev

    2017-01-01

    Full Text Available An alternative way to increase plant productivity through the use of nitrogen fertilizers is to improve the efficiency of nitrogen utilization via genetic engineering. The effects of overexpression of pine glutamine synthetase (GS gene and nitrogen availability on growth and leaf pigment levels of two Betula species were studied. Untransformed and transgenic plants of downy birch (B. pubescens and silver birch (B. pendula were grown under open-air conditions at three nitrogen regimes (0, 1, or 10 mM for one growing season. The transfer of the GS1a gene led to a significant increase in the height of only two transgenic lines of nine B. pubescens, but three of five B. pendula transgenic lines were higher than the controls. In general, nitrogen supply reduced the positive effect of the GS gene on the growth of transgenic birch plants. No differences in leaf pigment levels between control and transgenic plants were found. Nitrogen fertilization increased leaf chlorophyll content in untransformed plants but its effect on most of the transgenic lines was insignificant. The results suggest that birch plants carrying the GS gene use nitrogen more efficiently, especially when growing in nitrogen deficient soil. Transgenic lines were less responsive to nitrogen supply in comparison to wild-type plants.

  18. Influence of Nitrogen Availability on Growth of Two Transgenic Birch Species Carrying the Pine GS1a Gene

    Science.gov (United States)

    Lebedev, Vadim G.; Kovalenko, Nina P.; Shestibratov, Konstantin A.

    2017-01-01

    An alternative way to increase plant productivity through the use of nitrogen fertilizers is to improve the efficiency of nitrogen utilization via genetic engineering. The effects of overexpression of pine glutamine synthetase (GS) gene and nitrogen availability on growth and leaf pigment levels of two Betula species were studied. Untransformed and transgenic plants of downy birch (B. pubescens) and silver birch (B. pendula) were grown under open-air conditions at three nitrogen regimes (0, 1, or 10 mM) for one growing season. The transfer of the GS1a gene led to a significant increase in the height of only two transgenic lines of nine B. pubescens, but three of five B. pendula transgenic lines were higher than the controls. In general, nitrogen supply reduced the positive effect of the GS gene on the growth of transgenic birch plants. No differences in leaf pigment levels between control and transgenic plants were found. Nitrogen fertilization increased leaf chlorophyll content in untransformed plants but its effect on most of the transgenic lines was insignificant. The results suggest that birch plants carrying the GS gene use nitrogen more efficiently, especially when growing in nitrogen deficient soil. Transgenic lines were less responsive to nitrogen supply in comparison to wild-type plants. PMID:28067821

  19. Seven different genes encode a diverse mixture of isoforms of Bet v 1, the major birch pollen allergen

    Directory of Open Access Journals (Sweden)

    Gilissen Ludovicus JWJ

    2006-07-01

    Full Text Available Abstract Background Pollen of the European white birch (Betula pendula, syn. B. verrucosa is an important cause of hay fever. The main allergen is Bet v 1, member of the pathogenesis-related class 10 (PR-10 multigene family. To establish the number of PR-10/Bet v 1 genes and the isoform diversity within a single tree, PCR amplification, cloning and sequencing of PR-10 genes was performed on two diploid B. pendula cultivars and one interspecific tetraploid Betula hybrid. Sequences were attributed to putative genes based on sequence identity and intron length. Information on transcription was derived by comparison with homologous cDNA sequences available in GenBank/EMBL/DDJB. PCR-cloning of multigene families is accompanied by a high risk for the occurrence of PCR recombination artifacts. We screened for and excluded these artifacts, and also detected putative artifact sequences among database sequences. Results Forty-four different PR-10 sequences were recovered from B. pendula and assigned to thirteen putative genes. Sequence homology suggests that three genes were transcribed in somatic tissue and seven genes in pollen. The transcription of three other genes remains unknown. In total, fourteen different Bet v 1-type isoforms were identified in the three cultivars, of which nine isoforms were entirely new. Isoforms with high and low IgE-reactivity are encoded by different genes and one birch pollen grain has the genetic background to produce a mixture of isoforms with varying IgE-reactivity. Allergen diversity is even higher in the interspecific tetraploid hybrid, consistent with the presence of two genomes. Conclusion Isoforms of the major birch allergen Bet v 1 are encoded by multiple genes, and we propose to name them accordingly. The present characterization of the Bet v 1 genes provides a framework for the screening of specific Bet v 1 genes among other B. pendula cultivars or Betula species, and for future breeding for trees with a reduced

  20. Footprint areas of pollen from alder (Alnus and birch (Betula in the UK (Worcester and Poland (Wrocław during 2005–2014

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    Carsten Ambelas Skjøth

    2015-12-01

    Full Text Available In this study we analyzed daily pollen concentrations of Alnus spp. and Betula spp. from Worcester, UK and Wrocław, Poland. We analyzed seasonality, annual pollen index and footprint areas for the observed pollen concentrations by using the trajectory model hybrid single particle Lagrangian integrated trajectory (HYSPLIT. We examined 10 years of data during the period 2005–2014 and found substantial differences in the seasonality, pollen indices and footprint areas. For both genera, concentrations in Wrocław are in general much higher, the seasons are shorter and therefore more intense than in Worcester. The reasons appear to be related to the differences in overall climate between the two sites and more abundant sources in Poland than in England. The footprint areas suggest that the source of the pollen grains are mainly local trees but appear to be augmented by remote sources, in particular for Betula spp. but only to a small degree for Alnus spp. For Betula spp., both sites appear to get contributions from areas in Germany, the Netherlands and Belgium, while known Betula spp. rich regions in Russia, Belarus and Scandinavia had a very limited impact on the pollen concentrations in Worcester and Wrocław. Substantial and systematic variations in pollen indices are seen for Betula spp. in Wrocław with high values every second year while a similar pattern is not observed for Worcester. This pattern was not reproduced for Alnus spp.

  1. Effects of root medium pH on root water transport and apoplastic pH in red-osier dogwood (Cornus sericea) and paper birch (Betula papyrifera) seedlings.

    Science.gov (United States)

    Zhang, W; Zwiazek, J J

    2016-11-01

    Soil pH is a major factor affecting plant growth. Plant responses to pH conditions widely vary between different species of plants. However, the exact mechanisms of high pH tolerance of plants are largely unknown. In the present study, we compared the pH responses of paper birch (Betula papyrifera) seedlings, a relatively sensitive species to high soil pH, with red-osier dogwood (Cornus sericea), reported to be relatively tolerant of high pH conditions. We examined the hypotheses that tolerance of plants to high root zone pH is linked to effective control of root apoplastic pH to facilitate nutrient and water transport processes In the study, we exposed paper birch and red-osier dogwood seedlings for six weeks to pH 5, 7 and 9 under controlled-environment conditions in hydroponic culture. Then, we measured biomass, gas exchange, root hydraulic conductivity, ferric chelate reductase (FCR) activity, xylem sap pH and the relative abundance of major elements in leaf protoplasts and apoplasts. The study sheds new light on the rarely studied high pH tolerance mechanisms in plants. We found that compared with paper birch, red-osier dogwood showed greater growth, higher gas exchange, and maintained higher root hydraulic conductivity as well as lower xylem sap pH under high pH conditions. The results suggest that the relatively high pH tolerance of dogwood is associated with greater water uptake ability and maintenance of low apoplastic pH. These traits may have a significant impact on the uptake of Fe and Mn by leaf cells.

  2. Study of the betulin enriched birch bark extracts effects on human carcinoma cells and ear inflammation

    Directory of Open Access Journals (Sweden)

    Dehelean Cristina A

    2012-11-01

    Full Text Available Abstract Background Pentacyclic triterpenes, mainly betulin and betulinic acid, are valuable anticancer agents found in the bark of birch tree. This study evaluates birch bark extracts for the active principles composition. Results New improved extraction methods were applied on the bark of Betula pendula in order to reach the maximum content in active principles. Extracts were analyzed by HPLC-MS, Raman, SERS and 13C NMR spectroscopy which revealed a very high yield of betulin (over 90%. Growth inhibiting effects were measured in vitro on four malignant human cell lines: A431 (skin epidermoid carcinoma, A2780 (ovarian carcinoma, HeLa (cervix adenocarcinoma and MCF7 (breast adenocarcinoma, by means of MTT assay. All of the prepared bark extracts exerted a pronounced antiproliferative effect against human cancer cell lines. In vivo studies involved the anti-inflammatory effect of birch extracts on TPA-induced model of inflammation in mice. Conclusions The research revealed the efficacy of the extraction procedures as well as the antiproliferative and anti-inflammatory effects of birch extracts.

  3. Ecological and phytopathological status of birch stands on the territory of Krasnoyarsk group of districts

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    A. I. Tatarintsev

    2015-04-01

    Full Text Available According to inspection data, the health and vital status of birch (Betula pendula Roth. stands in Krasnoyarsk group of lands (southern part of Central Siberia were estimated (established as satisfactory in general; about half of birch stands near urbanized areas were weakened. The condition of stands decreased significantly with increased recreation use, the effect of technogenic pollution was negligible. The most valuable (important representatives of pathogenic biota identified on birch trees were infestations of necrotic cancer and rot diseases. In birch stands the bacterial dropsy was found to be widespread (agent of infection – Erwinia multivora Scz.-Parf, occurrence of the disease ranged from a single ill tree up to 10–38 % of the stands. The birch stands in taiga areas were affected to a greater extent than in forest-steppe; there were high yield class stands on moist soils. Prevalence of bacteriosis rose with increasing stand age and density and not dependent on recreation use level. Trees with dropsy are dead in fact or potentially. In taiga birch forests the infection and rot of roots was caused by honey agaric (Armillaria mellea sensu lato, that lead to single or, rarely, group tree drying and the fungus usually eliminated already weakened trees. Wood biomass was destroyed by complex of aphyllophorous Hymenomycetes, their hemiparasitic species caused stem rots that decreased stand marketability and also resulted in rot-realated wind-break accumulation. Occurrence of rot was significantly higher in second growth birch stands, possibly above 20 %; the relationship between rot prevalence and forest assessment was not revealed.

  4. Processing of pine (Pinus sylvestris) and birch (Betula pubescens) leaf material in a small river system in the northern Cairngorms, Scotland

    Science.gov (United States)

    Collen, P.; Keay, E. J.; Morrison, B. R. S.

    Processing rates, and macroinvertebrate colonisation, of pine needles and birch leaves were studied at eight sites on the river Nethy, a small river system in the Cairngorm region of north-eastern Scotland. Throughout this river system, processing rates were slow for pine (k values 0.0015-0.0034 day-1) and medium to fast for birch (k values 0.0085-0.0331 day-1). Plecopteran shredders dominated both pine and birch leaf packs during the early part of the experiment while chironomids were more important in the latter stages. It is suggested that the slow processing rate of pine needles could adversely affect the productivity of streams, particularly where needles provide the major allochthonous energy source and retentive features are limited. Forest managers should consider this when creating new pinewoods in treeless areas as it will take many years for the trees to reach a size at which they can effectively contribute retentive features, in the form of woody debris, to streams.

  5. Soil Chemical and Microbial Properties in a Mixed Stand of Spruce and Birch in the Ore Mountains (Germany—A Case Study

    Directory of Open Access Journals (Sweden)

    Karoline Schua

    2015-06-01

    Full Text Available A major argument for incorporating deciduous tree species in coniferous forest stands is their role in the amelioration and stabilisation of biogeochemical cycles. Current forest management strategies in central Europe aim to increase the area of mixed stands. In order to formulate statements about the ecological effects of mixtures, studies at the stand level are necessary. In a mixed stand of Norway spruce (Picea abies (L. Karst. and silver birch (Betula pendula Roth in the Ore Mountains (Saxony, Germany, the effects of these two tree species on chemical and microbial parameters in the topsoil were studied at one site in the form of a case study. Samples were taken from the O layer and A horizon in areas of the stand influenced by either birch, spruce or a mixture of birch and spruce. The microbial biomass, basal respiration, metabolic quotient, pH-value and the C and N contents and stocks were analysed in the horizons Of, Oh and A. Significantly higher contents of microbial N were observed in the Of and Oh horizons in the birch and in the spruce-birch strata than in the stratum containing only spruce. The same was found with respect to pH-values in the Of horizon and basal respiration in the Oh horizon. Compared to the spruce stratum, in the birch and spruce-birch strata, significantly lower values were found for the contents of organic C and total N in the A horizon. The findings of the case study indicated that single birch trees have significant effects on the chemical and microbial topsoil properties in spruce-dominated stands. Therefore, the admixture of birch in spruce stands may distinctly affect nutrient cycling and may also be relevant for soil carbon sequestration. Further studies of these functional aspects are recommended.

  6. Genetic diversity of F1 and F2 interspecific hybrids between dwarf birch (Betula nana L.) and Himalayan birch (B. utilis var. jacquemontii (Spach) Winkl. 'Doorenbos') using RAPD-PCR markers and ploidy analysis.

    Science.gov (United States)

    Czernicka, Małgorzata; Pławiak, Jarosław; Muras, Piotr

    2014-01-01

    Crosses between Betula nana and B. utilis 'Doorenbos' were undertaken in order to obtain interspecific hybrids which could be characterized by wide spreading stems, strong branching habit, decorative clear white bark and an interesting shape of purple leaves. The research purpose was to examine genetic diversity of the 16 F1 and F2 putative progenies by using the RAPD-PCR method and the ploidy analysis. A total of 242 RAPD markers were scored with 24 primers and 220 (90.9%) polymorphic bands were found. In the NJ dendrogram, cluster I consisted of the female parent--B. nana and 12 hybrids and cluster II grouped the male parent--B. utilis 'Doorenbos' with 4 hybrids (F2/2, F1/8, F1/7 and F2/1). The 2-D scaling by PCoA was in agreement with the similarity index, i.e. two hybrids (F1/8, F2/2) grouped with the male parent while others with female parent. Classification of the hybrid plants by chromosome counting demonstrated that 13 hybrids were confirmed with accurate chromosome counts as being diploid (2n=2x=28) and 3 plants (F1/7, F1/8, F2/2) as triploid with 42 chromosomes.

  7. Growth of Scots Pine and Silver Birch Seedlings on Different Nursery Container Media

    Directory of Open Access Journals (Sweden)

    Fahrettin TILKI

    2014-12-01

    Full Text Available Peat has been the most common growing medium in tree nurseries, either alone or as a component of growing media mixes. However, as a result of increasing costs and decreasing amount of peat, seedling-growers are seeking more local growing medium components. In this study, container seedlings of Scots pine (Pinus sylvestris L. and silver birch (Betula pendula Roth were grown in pure peat and peat mixtures containing perlite and zeolite.  Physical parameters (height, shoot diameter, root dry weight, shoot dry weight, total dry weight were measured along with several morphological parameters (sturdiness quotient, height/diameter, shoot/root ratio. The zeolite additive in peat changed some media properties, and significant relation was established between some morphological attributes of seedlings and some medium properties in both species. On average, the seedlings grew best in pure peat, but zeolite additions to peat did not affect some morphological parameters negatively. The results suggest that zeolite has potential to be used as a component of peat based growing medium mixtures, and addition of zeolite to peat container medium in proportions of 10% by volume in Scots pine and up to 20% in silver birch was shown to be a feasible material for growing Scots pine and silver birch seedlings.

  8. Host species and strain combination determine growth reduction of spruce and birch seedlings colonized by root-associated dark septate endophytes.

    Science.gov (United States)

    Reininger, Vanessa; Grünig, Christoph R; Sieber, Thomas N

    2012-04-01

    Interactions of Betula pendula and Picea abies with dark septate endophytes of the Phialocephala fortinii-Acephala applanata species complex (PAC) were studied. PAC are ubiquitous fungal root symbionts of many woody plant species but their ecological role is largely unknown. Sterile birch and spruce seedlings in monoculture and mixed culture were exposed to four PAC strains, added either singularly or paired in all possible combinations at 18°C and 23°C. Plant and fungal biomass was determined after 4 months. The most significant factors were strain and host combination. One of the strains significantly reduced biomass gain of spruce but not of birch. Plant biomass was negatively correlated with total endophytic fungal biomass in half of the strain - plant combinations. Endophytic PAC biomass was four times higher in spruce (≈ 40 mg g(-1) drw) than in birch (≈ 10 mg g(-1) drw). Competition between strains was strain-dependent with some strains significantly reducing colonization density of other strains, and, thus, attenuating adverse effects of 'pathogenic' strains on plant growth in some strain - plant combinations. Biomass gain of spruce but not of birch was significantly reduced at higher temperature. In conclusion, host, fungal genotype, colonization density and presence of a competing PAC strain were the main determining factors for plant growth.

  9. Features of secondary birch young stands in low mountain Pokuttya (Ukrainian Carpathian mts.

    Directory of Open Access Journals (Sweden)

    S. Y. Milevskaya

    2015-06-01

    Full Text Available Forest landscapes of the region during the last 3–5 centuries undergone the profound anthropogenic transformation. Secondary young stands occupy 25% of the total forest area. The problem of derivatives is particularly relevant for the modern forest typology in the Carpathian region. It requires the reflection in its dynamic trends shaping the stands, especially mixed young stands. The aim of our study consisted in getting the knowledge of the structural features of the secondary phytocoenosis of birch young stands in this area.The object of the study was age class I saplings growing in the mountainous part of Pokuttya, particularly in the basin of the Lutshka River. The conceptual basis of our study is the modern dynamic vision that every forest type is a consecutive series of forest plant communities within each type of homogeneous growing conditions. We apply methods of ecological-floristic research of the Brown-Blanke school in the interpretation of the Polish school phytosociology. However we also take into account both syntaxonomy generalizations of the Ukrainian scientists. The actual material comprises the original geobotanical studies with fixation of the vast majority of species in plant communities. Mainly the species having diagnostic value to separate syntaxons were taken into account in the analytical processing. Young forest stands (with the height of 8–12 m and crown cover of 70% together form the trees Betula pendula and B. pubescens. Fairly numerous admixture is formed by trees Alnus incana; besides, there are Fagus sylvatica, Populus tremula, Quercus robur, Padus avium. For dominants, they can be called “grey-alder birch blackberry sedge bracken fern” – Betula pendula+Alnus incana–Rubus caesius–Carex brizoides+Pteridium aquilinum. It is rich in floristic composition of the plant communities. They contain at least 12 species of trees, 3 species of shrubs, 4 species of bushes and 89 species of herbs. Diagnostic

  10. Leaf surface lipophilic compounds as one of the factors of silver birch chemical defense against larvae of gypsy moth.

    Directory of Open Access Journals (Sweden)

    Vyacheslav V Martemyanov

    Full Text Available Plant chemical defense against herbivores is a complex process which involves a number of secondary compounds. It is known that the concentration of leaf surface lipophilic compounds (SLCs, particularly those of flavonoid aglycones are increased with the defoliation treatment of silver birch Betula pendula. In this study we investigated how the alteration of SLCs concentration in the food affects the fitness and innate immunity of the gypsy moth Lymantria dispar. We found that a low SLCs concentrations in consumed leaves led to a rapid larval development and increased females' pupae weight (= fecundity compared to larvae fed with leaves with high SLCs content. Inversely, increasing the compounds concentration in an artificial diet produced the reverse effects: decreases in both larval weight and larval survival. Low SLCs concentrations in tree leaves differently affected larval innate immunity parameters. For both sexes, total hemocytes count in the hemolymph increased, while the activity of plasma phenoloxidase decreased when larvae consume leaves with reduced content of SLCs. Our results clearly demonstrate that the concentration of SLCs in silver birch leaves affects not only gypsy moth fitness but also their innate immune status which might alter the potential resistance of insects against infections and/or parasitoids.

  11. Phenolic compounds and expression of 4CL genes in silver birch clones and Pt4CL1a lines.

    Science.gov (United States)

    Sutela, Suvi; Hahl, Terhi; Tiimonen, Heidi; Aronen, Tuija; Ylioja, Tiina; Laakso, Tapio; Saranpää, Pekka; Chiang, Vincent; Julkunen-Tiitto, Riitta; Häggman, Hely

    2014-01-01

    A small multigene family encodes 4-coumarate:CoA ligases (4CLs) catalyzing the CoA ligation of hydroxycinnamic acids, a branch point step directing metabolites to a flavonoid or monolignol pathway. In the present study, we examined the effect of antisense Populus tremuloides 4CL (Pt4CL1) to the lignin and soluble phenolic compound composition of silver birch (Betula pendula) Pt4CL1a lines in comparison with non-transgenic silver birch clones. The endogenous expression of silver birch 4CL genes was recorded in the stems and leaves and also in leaves that were mechanically injured. In one of the transgenic Pt4CL1a lines, the ratio of syringyl (S) and guaiacyl (G) lignin units was increased. Moreover, the transcript levels of putative silver birch 4CL gene (Bp4CL1) were reduced and contents of cinnamic acid derivatives altered. In the other two Pt4CL1a lines changes were detected in the level of individual phenolic compounds. However, considerable variation was found in the transcript levels of silver birch 4CLs as well as in the concentration of phenolic compounds among the transgenic lines and non-transgenic clones. Wounding induced the expression of Bp4CL1 and Bp4CL2 in leaves in all clones and transgenic lines, whereas the transcript levels of Bp4CL3 and Bp4CL4 remained unchanged. Moreover, minor changes were detected in the concentrations of phenolic compounds caused by wounding. As an overall trend the wounding decreased the flavonoid content in silver birches and increased the content of soluble condensed tannins. The results indicate that by reducing the Bp4CL1 transcript levels lignin composition could be modified. However, the alterations found among the Pt4CL1a lines and the non-transgenic clones were within the natural variation of silver birches, as shown in the present study by the clonal differences in the transcripts levels of 4CL genes, soluble phenolic compounds and condensed tannins.

  12. Phenolic compounds and expression of 4CL genes in silver birch clones and Pt4CL1a lines.

    Directory of Open Access Journals (Sweden)

    Suvi Sutela

    Full Text Available A small multigene family encodes 4-coumarate:CoA ligases (4CLs catalyzing the CoA ligation of hydroxycinnamic acids, a branch point step directing metabolites to a flavonoid or monolignol pathway. In the present study, we examined the effect of antisense Populus tremuloides 4CL (Pt4CL1 to the lignin and soluble phenolic compound composition of silver birch (Betula pendula Pt4CL1a lines in comparison with non-transgenic silver birch clones. The endogenous expression of silver birch 4CL genes was recorded in the stems and leaves and also in leaves that were mechanically injured. In one of the transgenic Pt4CL1a lines, the ratio of syringyl (S and guaiacyl (G lignin units was increased. Moreover, the transcript levels of putative silver birch 4CL gene (Bp4CL1 were reduced and contents of cinnamic acid derivatives altered. In the other two Pt4CL1a lines changes were detected in the level of individual phenolic compounds. However, considerable variation was found in the transcript levels of silver birch 4CLs as well as in the concentration of phenolic compounds among the transgenic lines and non-transgenic clones. Wounding induced the expression of Bp4CL1 and Bp4CL2 in leaves in all clones and transgenic lines, whereas the transcript levels of Bp4CL3 and Bp4CL4 remained unchanged. Moreover, minor changes were detected in the concentrations of phenolic compounds caused by wounding. As an overall trend the wounding decreased the flavonoid content in silver birches and increased the content of soluble condensed tannins. The results indicate that by reducing the Bp4CL1 transcript levels lignin composition could be modified. However, the alterations found among the Pt4CL1a lines and the non-transgenic clones were within the natural variation of silver birches, as shown in the present study by the clonal differences in the transcripts levels of 4CL genes, soluble phenolic compounds and condensed tannins.

  13. Quantification of C uptake in subarctic birch forest after setback by an extreme insect outbreak

    DEFF Research Database (Denmark)

    Heliasz, Michal; Johansson, Torbjörn; Lindroth, Anders

    2011-01-01

    The carbon dynamics of northern natural ecosystems contribute significantly to the global carbon balance. Periodic disturbances to these dynamics include insect herbivory. Larvae of autumn and winter moths (Epirrita autumnata and Operophtera brumata) defoliate mountain birch (Betula pubescens) fo...

  14. Artificially decreased vapour pressure deficit in field conditions modifies foliar metabolite profiles in birch and aspen.

    Science.gov (United States)

    Lihavainen, Jenna; Keinänen, Markku; Keski-Saari, Sarita; Kontunen-Soppela, Sari; Sõber, Anu; Oksanen, Elina

    2016-07-01

    Relative air humidity (RH) is expected to increase in northern Europe due to climate change. Increasing RH reduces the difference of water vapour pressure deficit (VPD) between the leaf and the atmosphere, and affects the gas exchange of plants. Little is known about the effects of decreased VPD on plant metabolism, especially under field conditions. This study was conducted to determine the effects of artificially decreased VPD on silver birch (Betula pendula Roth.) and hybrid aspen (Populus tremula L.×P. tremuloides Michx.) foliar metabolite and nutrient profiles in a unique free air humidity manipulation (FAHM) field experiment during the fourth season of humidity manipulation, in 2011. Long-term exposure to decreased VPD modified nutrient homeostasis in tree leaves, as demonstrated by a lower N concentration and N:P ratio in aspen leaves, and higher Na concentration and lower K:Na ratio in the leaves of both species in decreased VPD than in ambient VPD. Decreased VPD caused a shift in foliar metabolite profiles of both species, affecting primary and secondary metabolites. Metabolic adjustment to decreased VPD included elevated levels of starch and heptulose sugars, sorbitol, hemiterpenoid and phenolic glycosides, and α-tocopherol. High levels of carbon reserves, phenolic compounds, and antioxidants under decreased VPD may modify plant resistance to environmental stresses emerging under changing climate.

  15. Evaluation and differentiation of the Betulaceae birch bark species and their bioactive triterpene content using analytical FT-vibrational spectroscopy and GC-MS

    Directory of Open Access Journals (Sweden)

    Cîntă-Pînzaru Simona

    2012-07-01

    Full Text Available Abstract Background Aiming to obtain the highest triterpene content in the extraction products, nine bark samples from the forest abundant flora of Apuseni Mountains, Romania were Raman spectroscopically evaluated. Three different natural extracts from Betula pendula Roth birch bark have been obtained and characterized using Fourier transform vibrational spectra. Results This study shows that principal components of the birch tree extract can be rapidly recognized and differentiated based on their vibrational fingerprint band shape and intensity. The vibrational spectroscopy results are supported by the GC-MS data. Based on IR and Raman analysis, one can conclude that all the extracts, independent on the solvent(s used, revealed dominant betulin species, followed by lupeol. Conclusions Since Raman measurements could also be performed on fresh plant material, we demonstrated the possibility to apply the present results for the prediction of the highest triterpene content in bark species, for the selection of harvesting time or individual genotypes directly in the field, with appropriate portable Raman equipment.

  16. Stomatal regulation, structural acclimation and metabolic shift towards defensive compounds reduce O3 load in birch under chronic O3 stress

    Science.gov (United States)

    Oksanen, E.; Riikonen, J.; Kontunen-Soppela, S.; Maenpaa, M.; Rousi, M.

    2009-12-01

    Northern forests are encountering new threats due to continuously increasing load of oxidative stress, e.g. due to rising tropospheric O3 levels, and simultaneous climate warming, which is more intense in northern latitudes as compared to global means. The proportion of silver birch (Betula pendula) in Finnish forests is expected to increase with climate warming. Unfortunately, we have growing evidence that the vitality and the carbon sink strength of birch trees are weakened under chronic O3 stress. In this study we investigated the effects of slightly elevated O3 concentration (1.3 x the ambient), temperature (T) and their combination on the antioxidant defense, gas exchange and leaf growth of Betula pendula saplings (clone 12) growing in open-field conditions over two growing seasons. The plants were measured for SLA (specific leaf area), total leaf area, net photosynthesis (Pn), stomatal conductance (gs), maximum rate of carboxylation (Vc,max), maximum rate of electron transport (Jmax), relative stomatal limitation to photosynthesis (ls), dark respiration (Rd), apoplastic concentrations of AA (ascorbic acid), DHA (dehydroascobate) and total ascorbate, the redox state of apoplastic ascorbate, and total antioxidant capacity. Elevated O3 enhanced the total antioxidant capacity in the apoplast in the first year of the experiment at the ambient T. However, during the second year of the experiment, the saplings responded to elevated O3 level by closing the stomata and by developing leaves with a lower leaf area per mass, rather than by accumulating ascorbate in the apoplast. O3 did not affect the total leaf area, whereas Pn was slightly and gs significantly reduced in the second year. Elevated T enhanced the total leaf area, Pn and Vc,max, redox state of ascorbate and total antioxidant capacity in the apoplast. The effects of T and O3 on total leaf area and net photosynthesis were counteractive. We were not able to detect significant differences in Rd between the

  17. Assessment of UV biological spectral weighting functions for phenolic metabolites and growth responses in silver birch seedlings.

    Science.gov (United States)

    Kotilainen, Titta; Venäläinen, Tuulia; Tegelberg, Riitta; Lindfors, Anders; Julkunen-Tiitto, Riitta; Sutinen, Sirkka; O'Hara, Robert B; Aphalo, Pedro J

    2009-01-01

    In research concerning stratospheric ozone depletion, action spectra are used as biological spectral weighting functions (BSWFs) for describing the effects of UV radiation on plant responses. Our aim was to evaluate the appropriateness of six frequently used BSWFs that differ in effectiveness with increasing wavelength. The evaluation of action spectra was based on calculating the effective UV radiation doses according to 1-2) two formulations of the generalized plant action spectrum, 3) a spectrum for ultraviolet induced erythema in human skin, 4) a spectrum for the accumulation of a flavonol in Mesembryanthemum crystallinum, 5) a spectrum for DNA damage in alfalfa seedlings and 6) the plant growth action spectrum. We monitored effects of UV radiation on the concentration of individual UV absorbing metabolites and chlorophyll concentrations in leaves and growth responses of silver birch (Betula pendula) seedlings. Experiments were conducted outdoors using plastic films attenuating different parts of the UV spectrum. Chlorophyll concentrations and growth were not affected by the UV treatments. The response to UV radiation varied between and within groups of phenolics. In general, the observed responses of phenolic groups and individual flavonoids were best predicted by action spectra extending into the UV-A region with moderate effectiveness.

  18. Effects of sugar beet chitinase IV on root-associated fungal community of transgenic silver birch in a field trial.

    Science.gov (United States)

    Pasonen, Hanna-Leena; Lu, Jinrong; Niskanen, Anna-Maija; Seppänen, Sanna-Kaisa; Rytkönen, Anna; Raunio, Janne; Pappinen, Ari; Kasanen, Risto; Timonen, Sari

    2009-10-01

    Heterogenous chitinases have been introduced in many plant species with the aim to increase the resistance of plants to fungal diseases. We studied the effects of the heterologous expression of sugar beet chitinase IV on the intensity of ectomycorrhizal (ECM) colonization and the structure of fungal communities in the field trial of 15 transgenic and 8 wild-type silver birch (Betula pendula Roth) genotypes. Fungal sequences were separated in denaturing gradient gel electrophoresis and identified by sequencing the ITS1 region to reveal the operational taxonomic units. ECM colonization was less intense in 7 out of 15 transgenic lines than in the corresponding non-transgenic control plants, but the slight decrease in overall ECM colonization in transgenic lines could not be related to sugar beet chitinase IV expression or total endochitinase activity. One transgenic line showing fairly weak sugar beet chitinase IV expression without significantly increased total endochitinase activity differed significantly from the non-transgenic controls in the structure of fungal community. Five sequences belonging to three different fungal genera (Hebeloma, Inocybe, Laccaria) were indicative of wild-type genotypes, and one sequence (Lactarius) indicated one transgenic line. In cluster analysis, the non-transgenic control grouped together with the transgenic lines indicating that genotype was a more important factor determining the structure of fungal communities than the transgenic status of the plants. With the tested birch lines, no clear evidence for the effect of the heterologous expression of sugar beet chitinase IV on ECM colonization or the structure of fungal community was found.

  19. BVOC responses to realistic nitrogen fertilization and ozone exposure in silver birch.

    Science.gov (United States)

    Carriero, G; Brunetti, C; Fares, S; Hayes, F; Hoshika, Y; Mills, G; Tattini, M; Paoletti, E

    2016-06-01

    Emission of BVOC (Biogenic Volatile Organic Compounds) from plant leaves in response to ozone exposure (O3) and nitrogen (N) fertilization is poorly understood. For the first time, BVOC emissions were explored in a forest tree species (silver birch, Betula pendula) exposed for two years to realistic levels of O3 (35, 48 and 69 ppb as daylight average) and N (10, 30 and 70 kg ha(-1) yr(-1), applied weekly to the soil as ammonium nitrate). The main BVOCs emitted were: α-pinene, β-pinene, limonene, ocimene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) and hexanal. Ozone exposure increased BVOC emission and reduced total leaf area. The effect on emission was stronger when a short-term O3 metric (concentrations at the time of sampling) rather than a long-term one (AOT40) was used. The effect of O3 on total leaf area was not able to compensate for the stimulation of emission, so that responses to O3 at leaf and whole-plant level were similar. Nitrogen fertilization increased total leaf area, decreased α-pinene and β-pinene emission, and increased ocimene, hexanal and DMNT emission. The increase of leaf area changed the significance of the emission response to N fertilization for most compounds. Nitrogen fertilization mitigated the effects of O3 exposure on total leaf area, while the combined effects of O3 exposure and N fertilization on BVOC emission were additive and not synergistic. In conclusion, O3 exposure and N fertilization have the potential to affect global BVOC via direct effects on plant emission rates and changes in leaf area.

  20. A review of bronze birch borer (Coleoptera: Buprestidae) life history, ecology, and management.

    Science.gov (United States)

    Muilenburg, Vanessa L; Herms, Daniel A

    2012-12-01

    Bronze birch borer (Agrilus anxius Gory) (Coleoptera: Buprestidae), a specialist wood-borer endemic to North America, is prone to periodic outbreaks that have caused widespread mortality of birch (Betula spp.) in boreal and north temperate forests. It is also the key pest of birch in ornamental landscapes. Amenity plantings have extended the distribution of birch in North America, for which we report an updated map. Life history and phenology also are summarized. Larvae feed primarily on phloem tissue of stems and branches, which can girdle and kill trees. Stressors such as drought, elevated temperature, and defoliation predispose trees to bronze birch borer colonization and trigger outbreaks, which implicates the availability of suitable host material in the bottom-up regulation of populations. Stress imposed by climate change may increase the frequency of outbreaks and alter the distribution of birch. Bronze birch borer has a diverse array of natural enemies, but their role in top-down population regulation has not been studied. There is substantial interspecific variation in resistance to this insect. North American species share a coevolutionary history with bronze birch borer and are much more resistant than Eurasian species, which are evolutionarily naïve. Potential resistance mechanisms are reviewed. The high susceptibility of Eurasian birch species and climatic similarities of North America and Eurasia create high risk of widespread birch mortality in Eurasia if the borer was inadvertently introduced. Bronze birch borer can be managed in amenity plantings through selection of resistant birch species, plant health care practices, and insecticides.

  1. Synchronous states of slowly rotating pendula

    Energy Technology Data Exchange (ETDEWEB)

    Kapitaniak, Marcin [Division of Dynamics, Technical University of Lodz, Stefanowskiego 1/15, 90-924 Lodz (Poland); Centre for Applied Dynamics Research, School of Engineering, University of Aberdeen, AB24 3UE Aberdeen, Scotland (United Kingdom); Czolczynski, Krzysztof; Perlikowski, Przemysław; Stefanski, Andrzej [Division of Dynamics, Technical University of Lodz, Stefanowskiego 1/15, 90-924 Lodz (Poland); Kapitaniak, Tomasz, E-mail: tomasz.kapitaniak@p.lodz.pl [Division of Dynamics, Technical University of Lodz, Stefanowskiego 1/15, 90-924 Lodz (Poland)

    2014-08-01

    Coupled systems that contain rotating elements are typical in physical, biological and engineering applications and for years have been the subject of intensive studies. One problem of scientific interest, which among others occurs in such systems is the phenomenon of synchronization of different rotating parts. Despite different initial conditions, after a sufficiently long transient, the rotating parts move in the same way — complete synchronization, or a permanent constant shift is established between their displacements, i.e., the angles of rotation — phase synchronization. Synchronization occurs due to dependence of the periods of rotating elements motion and the displacement of the base on which these elements are mounted. We review the studies on the synchronization of rotating pendula and compare them with the results obtained for oscillating pendula. As an example we consider the dynamics of the system consisting of n pendula mounted on the movable beam. The pendula are excited by the external torques which are inversely proportional to the angular velocities of the pendula. As the result of such excitation each pendulum rotates around its axis of rotation. It has been assumed that all pendula rotate in the same direction or in the opposite directions. We consider the case of slowly rotating pendula and estimate the influence of the gravity on their motion. We classify the synchronous states of the identical pendula and observe how the parameters mismatch can influence them. We give evidence that synchronous states are robust as they exist in the wide range of system parameters and can be observed in a simple experiment.

  2. Interfacial instabilities and Kapitsa pendula

    Science.gov (United States)

    Krieger, Madison

    2015-11-01

    Determining the critera for onset and amplitude growth of instabilities is one of the central problems of fluid mechanics. We develop a parallel between the Kapitsa effect, in which a pendulum subject to high-frequency low-amplitude vibrations becomes stable in the inverted position, and interfaces separating fluids of different density. It has long been known that such interfaces can be stabilized by vibrations, even when the denser fluid is on top. We demonstrate that the stability diagram for these fluid interfaces is identical to the stability diagram for an appopriate Kapitsa pendulum. We expand the robust, ``dictionary''-type relationship between Kapitsa pendula and interfacial instabilities by considering the classical Rayleigh-Taylor, Kelvin-Helmholtz and Plateau instabilities, as well as less-canonical examples ranging in scale from the micron to the width of a galaxy.

  3. Environ: E00796 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available E00796 Birch Medicinal herb Quercetin [CPD:C00389], Kaempferol [CPD:C05903], Salicy...late, Tannin, Ascorbate [CPD:C00072] Betula pendula [TAX:3505] Betulaceae Birch leaves Medicinal herbs [BR:br08322] Dicot plants: rosids Betulaceae (birch famly) E00796 Birch ...

  4. Extraction of betulin from bark of Betula platyphylla by supercritical carbon dioxide extraction

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-hong; YU Tao; WANG Yang

    2003-01-01

    Betulin, which is a medicinal pentacyclic triterpene, is abundant in the bark of white birch (Betula platyphlly). The bark of birch was collected at Tayuan Forest Farm of Jiagedaqi, Heilongjiang Province in September 2000. Supercritical fluid extraction (SFE) that is a new separation technology has been used for the processing pharmaceutical and natural products. In this paper, the extraction of betulin from the bark of birch by supercritical CO2 extraction was studied. The authors investigated and analyzed a few parameters such as modifier dosage, extraction pressure and extraction temperature. The optimal extraction conditions showed that the modifier dosage used for per gram bark powder was 1.5 mL, the extraction pressure was at 20 Mpa, and the extraction temperature was at 55 ℃. The velocity of flow of liquid CO2 was at 10 kg/h. The pressure and temperature in separation vessel were at 5.5 Mpa and 50 ℃, respectively.

  5. Genetic relationship of interspecies for eight birch species

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Genetic relationships of eight species of genus Betula were evaluatedusing ISSR marks. A total of 236 loci were generated from 17 ISSR primers. Perce ntage of polymorphic bands (PPB) varied from 5.93 to 19.92. The highest and the lowest level of genetic differentiation were detected in B. Ovalifolia and B. Ma ximowicziana Regel respectively. In these eight species, genetic diversity of bi rch (HT) was 24.38 %, and the genetic variation (GST ) interspecies was accounti ng for 79.36% of total genetic variation. According to the cluster results of ge netic distance, the eight species were classified into three groups as B. Davur ica, B. Ovalifolia, B. Platyphylla and B. Pendula for one group;B. Schmidtii, B . Costata and B. Ermanii Cham. Var. Communis for one group, and B. Maximowiczian a Regel for another group. The result of cluster is consistent with traditional morphological classification.

  6. The role of summer precipitation and summer temperature in establishment and growth of dwarf shrub Betula nana in northeast Siberian tundra

    DEFF Research Database (Denmark)

    Li, Bingxi; Heijmans, Monique M P D; Berendse, Frank;

    2016-01-01

    It is widely believed that deciduous tundra-shrub dominance is increasing in the pan-Arctic region, mainly due to rising temperature. We sampled dwarf birch (Betula nana L.) at a northeastern Siberian tundra site and used dendrochronological methods to explore the relationship between climatic...

  7. The role of summer precipitation and summer temperature in establishment and growth of dwarf shrub Betula nana in northeast Siberian tundra

    NARCIS (Netherlands)

    Bingxi Li,; Heijmans, M.M.P.D.; Berendse, F.; Blok, D.; Maximov, T.; Sass-Klaassen, U.G.W.

    2016-01-01

    It is widely believed that deciduous tundrashrub
    dominance is increasing in the pan-Arctic region,
    mainly due to rising temperature. We sampled dwarf birch
    (Betula
    nana L.) at a northeastern Siberian tundra site and
    used dendrochronological methods to explore the relationship
    bet

  8. Allocation of carbon to growth and secondary metabolites in birch seedlings under UV-B radiation and CO{sub 2} exposure

    Energy Technology Data Exchange (ETDEWEB)

    Lavola, A.; Julkunen-Tiitto, R. [Univ. of Joensuu, Dept. of Biology, Joensuu (Finland); Rosa, T.M. de la [Univ. of Joensuu, Faculty of Forestry, Joensuu (Finland)

    2000-07-01

    In plants, the allocation of carbon to secondary metabolites has been shown to be determined by both the availability of resources (e.g., CO{sub 2} concentration) and by specific stress factors (e.g., ultraviolet [UV]-radiation). It has been suggested that, in combination, CO{sub 2} and UV-B radiation may differentially affect plant growth and morphogenic parameters, and elevated CO{sub 2} may ameliorate the effects of UV-B radiation, In the present work, the effects of increased atmospheric CO{sub 2} concentration and UV-B radiation on growth and the accumulation of different types of secondary metabolites were studied in silver birch (Betula pendula Roth). Seedlings were exposed to 350 and 700 {mu} mol mol{sup -1} of CO{sub 2} in a greenhouse. At both CO{sub 2} levels, additional UV-B was either present (8.16 kJ m{sup -2} day{sup -1} of biologically effective UV-B irradiance) or absent. The time course of accumulation of individual secondary compounds and the shifts in allocation of carbon between biomass and the secondary metabolites (phenolic acids, flavonoids, condensed tannins) were studied during a 1-month-long exposure. Additionally, the activities of enzymes (L-phenylalanine ammonia-lyase [PAL], EC 4.3.1.5; peroxidase, EC 1.11.1.7; polyphenol oxidase, EC 1.10.3.1) were determined for leaves. UV-B radiation significantly increased biomass, PAL activity, and the accumulation of phenolic acids and flavonoids in seedlings. Elevated CO{sub 2} concentration increased the activities of all the enzymes studied and the accumulation of condensed tannins in leaves, especially with UV-B radiation. Because the observed UV-B induction of flavonoids was smaller under a high CO{sub 2} concentration, it was suggested that the excess of carbon in the atmosphere may moderate the effect of UV-B by increasing the metabolic activity of leaves (high enzyme activities) and by changing the allocation of internal carbon between different primary and secondary metabolites in the

  9. Changes in flowering of birch in the Czech Republic in recent 25 years (1991–2015 in connection with meteorological variables

    Directory of Open Access Journals (Sweden)

    Lenka Hajkova

    2015-12-01

    Full Text Available The paper presents the results of long-term phenological observations of silver birch (Betula pendula during the years 1991–2015 across the phenological network of the Czech Hydrometeorological Institute (CHMI – Český hydrometeorologický ústav. The data assembled over this period were used for identification of timing of generative phenophases associated with pollen release into the air: inflorescence emergence 10%, beginning of flowering 10%, beginning of flowering 50%, beginning of flowering 100%, and end of flowering. The stations are situated at altitudes from 155 m (Doksany to 1102 m (Modrava. The average timing of beginning of flowering 10% was 8th April (Lednice = lowland station and 14th May (Modrava = mountain station; the average timing of beginning of flowering 50% was 12th April (Lednice and 20th May (Modrava; the average timing of beginning of flowering 100% was 18th April (Lednice and 22nd May (Modrava, and the average timing of end of flowering was 26th April (Lednice and 28th May (Modrava. The totals of effective temperatures above 5°C (TS5 and sums of daily precipitation were used as a bio-climatological criterion for assessment of the dependence of phenological phases on meteorological variables. The average sums of TS5 and the average sums of daily precipitation total were as follows: 61.0–80.8°C, 82.8–327.4 mm (inflorescence emergence; 105.2–106.4°C, 85.9–365.2 mm (beginning of flowering 10%; 124.8–130.8°C, 89.8–385.9 mm (beginning of flowering 50%; 144.7–158.6°C, 95.2–390.7 mm (beginning of flowering 100%; and 181.6–223.8°C, 104.7–427.4 mm (end of flowering. Synoptic situations occurring during interphase intervals were obtained – the most often found synoptic situations were B (stationary trough over Central Europe, Bp (east travelling trough, NEa (northeast anticyclonic situation, Sa (south anticyclonic situation and SWc2 (southwest cyclonic situation moving northeast to eastwards. The

  10. Winter Birch Trees

    Science.gov (United States)

    Sweeney, Debra; Rounds, Judy

    2011-01-01

    Trees are great inspiration for artists. Many art teachers find themselves inspired and maybe somewhat obsessed with the natural beauty and elegance of the lofty tree, and how it changes through the seasons. One such tree that grows in several regions and always looks magnificent, regardless of the time of year, is the birch. In this article, the…

  11. Cadmium accumulation and its effect on the in vitro growth of woody fleabane and mycorrhized white birch

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, R.; Bertrand, A.; Casares, A. [Departamento de Biologia de Organismos y Sistemas, Oviedo University, Catedratico Rodrigo Uria s/n, 33071 Oviedo (Spain); Garcia, R. [Departamento de Quimica Fisica y Analitica, Oviedo University, Julian Claveria s/n, 33071 Oviedo (Spain); Gonzalez, A. [Departamento de Biologia de Organismos y Sistemas, Oviedo University, Catedratico Rodrigo Uria s/n, 33071 Oviedo (Spain)], E-mail: aidag@uniovi.es; Tames, R.S. [Departamento de Biologia de Organismos y Sistemas, Oviedo University, Catedratico Rodrigo Uria s/n, 33071 Oviedo (Spain)

    2008-04-15

    The effect of Cd on woody fleabane (Dittrichia viscosa (L.) Greuter) and white birch (Betula celtiberica Rothm. and Vasc.) was examined. Woody fleabane and white birch were grown in vitro in Murashige, T., Skoog, F., [1962. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant. 15, 473-479] (MS) plus Cd (10 mg Cd kg{sup -1}) and except for root length in white birch, plant development was inhibited when Cd was added. Cd accumulation in above-ground tissues showed differences among clones, reaching 1300 and 463 mg Cd kg{sup -1} dry wt. in selected clones of woody fleabane and white birch, respectively. Tolerance of Paxillus filamentosus (Scop) Fr. to Cd was also examined before mycorrhization. Plants of mycorrhized white birch grown in the presence of Cd had a better development and accumulated more Cd in their shoots than the non-mycorrhized ones. The use of selected clones of woody fleabane and the mycorrhization of white birch enhance extraction efficiency from contaminated soils in phytoremediation programs. - The high accumulation of Cd observed in selected clones of Dittrichia viscosa and mycorrhized Betula celtiberica grown in vitro implies a potential application for phytoextraction.

  12. Interfacial fluid instabilities and Kapitsa pendula

    CERN Document Server

    Krieger, Madison Ski

    2015-01-01

    The onset and development of instabilities is one of the central problems in fluid mechanics. Here we develop a connection between instabilities of free fluid interfaces and inverted pendula. When acted upon solely by the gravitational force, the inverted pendulum is unstable. This position can be stabilised by the Kapitsa phenomenon, in which high-frequency low-amplitude vertical vibrations of the base creates a fictitious force which opposes the gravitational force. By transforming the dynamical equations governing a fluid interface into an appropriate pendulum, we demonstrate how stability can be induced in fluid systems by properly tuned vibrations. We construct a "dictionary"-type relationship between various pendula and the classical Rayleigh-Taylor, Kelvin-Helmholtz, Rayleigh-Plateau and the self-gravitational instabilities. This makes several results in control theory and dynamical systems directly applicable to the study of "tunable" fluid instabilities, where the critical wavelength depends on the e...

  13. Effect of different steam explosion conditions on methane potential and enzymatic saccharification of birch.

    Science.gov (United States)

    Vivekanand, Vivekanand; Olsen, Elisabeth F; Eijsink, Vincent G H; Horn, Svein J

    2013-01-01

    Birch (Betula pubescens) was steam exploded at 13 different conditions with temperatures ranging from 170 to 230 °C and residence times ranging from 5 to 15 min. Increasing severity in the pretreatment led to degradation of xylan and formation of pseudo-lignin. The effect of the pretreatments was evaluated by running enzymatic saccharification and anaerobic digestion followed by analysis of sugar and methane yields, respectively. Enzymatically released glucose increased with pretreatment severity up to 220 °C for 10 min and levels of solubilized glucose reached 97% of the theoretical maximum. The highest methane yield (369 mL gVS(-1)) was obtained at a severity factor of 4.5 and this yield was 1.8 times higher than the yield from untreated birch. Enzymatic glucose yields and methane yields were generally correlated. The results indicate that steam-exploded birch can be effectively converted to either glucose or methane.

  14. Shotgun Bisulfite Sequencing of the Betula platyphylla Genome Reveals the Tree’s DNA Methylation Patterning

    Directory of Open Access Journals (Sweden)

    Chang Su

    2014-12-01

    Full Text Available DNA methylation plays a critical role in the regulation of gene expression. Most studies of DNA methylation have been performed in herbaceous plants, and little is known about the methylation patterns in tree genomes. In the present study, we generated a map of methylated cytosines at single base pair resolution for Betula platyphylla (white birch by bisulfite sequencing combined with transcriptomics to analyze DNA methylation and its effects on gene expression. We obtained a detailed view of the function of DNA methylation sequence composition and distribution in the genome of B. platyphylla. There are 34,460 genes in the whole genome of birch, and 31,297 genes are methylated. Conservatively, we estimated that 14.29% of genomic cytosines are methylcytosines in birch. Among the methylation sites, the CHH context accounts for 48.86%, and is the largest proportion. Combined transcriptome and methylation analysis showed that the genes with moderate methylation levels had higher expression levels than genes with high and low methylation. In addition, methylated genes are highly enriched for the GO subcategories of binding activities, catalytic activities, cellular processes, response to stimulus and cell death, suggesting that methylation mediates these pathways in birch trees.

  15. Biomass and nutrient cycle in fertilized and unfertilized pine, mixed birch and pine and spruce stands on a drained mire.

    OpenAIRE

    Finér, Leena

    1989-01-01

    Biomass, biomass increment and nutrient cycling were studied in (1) a Scots pine (Pinus sylvestris) stand, (2) a Norway spruce (Picea abies) stand and (3) a mixed birch (Betula pubescens)/pine stand on a drained mire at Ilomantsi, eastern Finland in 1979-85. In addition, the effect of NPK and micronutrient fertilizer treatment was studied. Above-ground and root measurements were taken. These data formed the basis of stand biomass and nutrient cycle simulations of fertilized and unfertilized s...

  16. COMPREHENSIVE CHARACTERISTIC OF PINE AND BIRCH SPECIES WITH DIFFERENT SCHEME OF COMBINATION Сравнительная характеристика сосново-березовых культур с различной схемой смешения

    Directory of Open Access Journals (Sweden)

    Shamiryan K. G.

    2012-09-01

    Full Text Available The article presents the characteristics of condition and growth of Pinus sylvestris and Betula Pendula in their cohabitation in poor sand soils (A2 in the condition of some forest enterprises of Voronezh region; the most effective way of combination of this species is revealed

  17. The smallest chimera state for coupled pendula

    Science.gov (United States)

    Wojewoda, Jerzy; Czolczynski, Krzysztof; Maistrenko, Yuri; Kapitaniak, Tomasz

    2016-01-01

    Chimera states in the systems of coupled identical oscillators are spatiotemporal patterns in which different groups of oscillators can exhibit coexisting synchronous and incoherent behaviors despite homogeneous coupling. Although these states are typically observed in large ensembles of oscillators, recently it has been suggested that chimera states may occur in the systems with small numbers of oscillators. Here, considering three coupled pendula showing chaotic behavior, we find the pattern of the smallest chimera state, which is characterized by the coexistence of two synchronized and one incoherent oscillator. We show that this chimera state can be observed in simple experiments with mechanical oscillators, which are controlled by elementary dynamical equations derived from Newton’s laws. Our finding suggests that chimera states are observable in small networks relevant to various real-world systems. PMID:27713483

  18. The smallest chimera state for coupled pendula

    Science.gov (United States)

    Wojewoda, Jerzy; Czolczynski, Krzysztof; Maistrenko, Yuri; Kapitaniak, Tomasz

    2016-10-01

    Chimera states in the systems of coupled identical oscillators are spatiotemporal patterns in which different groups of oscillators can exhibit coexisting synchronous and incoherent behaviors despite homogeneous coupling. Although these states are typically observed in large ensembles of oscillators, recently it has been suggested that chimera states may occur in the systems with small numbers of oscillators. Here, considering three coupled pendula showing chaotic behavior, we find the pattern of the smallest chimera state, which is characterized by the coexistence of two synchronized and one incoherent oscillator. We show that this chimera state can be observed in simple experiments with mechanical oscillators, which are controlled by elementary dynamical equations derived from Newton’s laws. Our finding suggests that chimera states are observable in small networks relevant to various real-world systems.

  19. Carbon and Nitrogen Transformations in Surface Soils Under Ermans Birch and Dark Coniferous Forests

    Institute of Scientific and Technical Information of China (English)

    DENG Xiao-Wen; HAN Shi-Jie; HU Yan-Ling; ZHOU Yu-Mei

    2009-01-01

    Soil samples were taken from an Ermans birch (Betula ermanii)-dark coniferous forest (Picea jezoensis and Abies nephrolepis) ecotone growing on volcanic ejecta in the northern slopc of Changbai Mountains of Northeast China,to compare soil carbon (C) and nitrogen (N) transformations in the two forests.The soil type is Umbri-Gelic Cambosols in Chinese Soil Taxonomy.Soil samples were incubated aerobically at 20 ℃ and field capacity of 700 g kg-1 over a period of 27 weeks.The amount of soil microbial biomass and net N mineralization were higher in the Ermans birch than the dark coniferous forest (P<0.05),whereas the cumulative C mineralization (as CO2 emission) in the dark coniferous forest exceeded that in the Ermans birch (P<0.05).Release of the cumulative dissolved organic C and dissolved organic N were greater in the Ermans birch than the dark coniferous forest (P<0.05).The results suggested that differences of forest types could result in considerable change in soil C and N transformations.

  20. The prospects for the survival of the population of a boreal relict species, Betula humilis Schrk., in a small isolated peat bog in the Łęczna - Włodawa Lakeland

    Directory of Open Access Journals (Sweden)

    Magdalena Pogorzelec

    2012-12-01

    Full Text Available An attempt was made to identify the major risks to the population of Betula humilis Schrk. existing in a small isolated transitional peat bog near Lake Bikcze, in the Łęczna-Włodawa Lakeland. The biometric features of 40 Betula humilis individuals were measured as well as the growth of shoots, flowering and fruiting were observed. Habitat conditions were characterized by making measurements of selected abiotic and biocenotic environmental factors. The obtained results allowed us to identify two main threats to the proper functioning of the study population. The first one is the possible loss of genetic identity of the species as a result of probable ongoing introgression by the potential crossing of Betula humilis with other species of the genus Betula, which are numerous in the flora of the studied area. Another threat is a change in habitat conditions (mainly light and water conditions, which is due to the accelerated secondary succession manifested by the expansion of common species such as Salix cinerea, Betula pendula, and Phragmites australis.

  1. Multi-headed chimera states in coupled pendula

    Science.gov (United States)

    Jaros, P.; Borkowski, L.; Witkowski, B.; Czolczynski, K.; Kapitaniak, T.

    2015-07-01

    We discuss the occurrence of the chimera states in the network of coupled, excited by the clock's mechanisms pendula. We find the patterns of multi-headed chimera states in which pendula clustered in different heads behave differently (oscillate with different frequencies) and create different types of synchronous states (complete or phase synchronization). The mathematical model of the network shows that the observed chimera states are controlled by elementary dynamical equations derived from the Newton's laws that are ubiquitous in many physical and engineering systems.

  2. Efficacy of recombinant birch pollen vaccine for the treatment of birch-allergic rhinoconjunctivitis

    DEFF Research Database (Denmark)

    Pauli, Gabrielle; Larsen, Tina H; Rak, Sabina

    2008-01-01

    BACKGROUND: Recombinant DNA technology has the potential to produce allergen-specific immunotherapy vaccines with defined composition. OBJECTIVE: To evaluate the effectiveness of a new recombinant birch pollen allergen vaccine in patients with birch pollen allergy. METHODS: A multicenter......, randomized, double-blind, placebo-controlled trial was undertaken to compare the following 3 vaccines in 134 adults with birch pollen allergy: recombinant birch pollen allergen vaccine (rBet v 1a), licensed birch pollen extract, natural purified birch pollen allergen (nBet v 1), and placebo. Patients...

  3. Fruit wall anatomical structure of the genus Betula section Lenta (Betulaceae

    Directory of Open Access Journals (Sweden)

    Olga V. Yatsenko

    2014-04-01

    Full Text Available The fruits of the Lentae are referred to lower syncarpous nuts. Unlike most birches, the three-lobed scales in section Lentae stay attached to the axis for a long time. The fruit wall is differentiated into epicarp (derivative of outer tissues of inferior ovary, the tissues of receptacular origin and the pericarp itself (mesocarp and the endocarp derivating from the ovary wall. The epicarp consists of two zones: epidermis and subepidermal zone. Two-four layers of larger sclerenchymatous cells represent the mesocarp. Several layers of parenchymatous cells, which are squeezed and partly obliterated by fruit maturity, compose endocarp. The morphogenetic type of fruit of the genus Betula section Lentae is the pyrenarium of the Olea-type.

  4. Spin-orbit coupling in a hexagonal ring of pendula

    CERN Document Server

    Salerno, Grazia; Ozawa, Tomoki; Price, Hannah M; Taxis, Ludovic; Pugno, Nicola M; Carusotto, Iacopo

    2016-01-01

    We consider the mechanical motion of a system of six macroscopic pendula which are connected with springs and arranged in a hexagonal geometry. When the springs are pre-tensioned, the coupling between neighbouring pendula along the longitudinal (L) and the transverse (T) directions are different: identifying the motion along the L and T directions as a spin-like degree of freedom, we theoretically and experimentally verify that the pre-tensioned springs result in a tunable spin-orbit coupling. We elucidate the structure of such a spin-orbit coupling in the extended two-dimensional honeycomb lattice, making connections to physics of graphene. The experimental frequencies and the oscillation patterns of the eigenmodes for the hexagonal ring of pendula are extracted from a spectral analysis of the motion of the pendula in response to an external excitation and are found to be in good agreement with our theoretical predictions. We anticipate that extending this classical analogue of quantum mechanical spin-orbit ...

  5. Icelandic Birch Polyploids—The Case of a Perfect Fit in Genome Size

    Directory of Open Access Journals (Sweden)

    K. Anamthawat-Jónsson

    2010-01-01

    Full Text Available Two birch species coexist in Iceland, dwarf birch Betula nana and tree birch B. pubescens. Both species are variable morphologically, which has been shown to be due to introgressive hybridization via interspecific hybrids. The aim of this study was to examine if the introgression could be related to genome size. We characterized 42 plants from Bifröst woodland morphologically and cytogenetically. The population consisted of diploid B. nana (38%, tetraploid B. pubescens (55%, and triploid hybrids (7%. Genome size was measured from 12 plants, using Feulgen DNA image densitometry (FDM on spring leaf buds and flow cytometry (FCM with dormant winter twigs. The use of winter twigs for FCM is novel. The average 1C-values for diploid, triploid, and tetraploid plants were 448, 666, and 882 Mbp, respectively. Monoploid genome sizes were found to be statistically constant among ploidy levels. This stability is in contrast to the different taxonomic positions of the di- and tetraploids and also contrasts with the frequent occurrence of genome downsizing in polyploids.

  6. Assessing the Potential Stem Growth and Quality of Yellow Birch Prior to Restoration: A Case Study in Eastern Canada

    Directory of Open Access Journals (Sweden)

    Alexis Achim

    2013-09-01

    Full Text Available Past silvicultural treatments have resulted in the high-grading mixed temperate forests of Québec, Canada. Despite recognition of this issue, the low occurrence of yellow birch (Betula alleghaniensis Britton within current stands raises questions about the potential of the species to grow and eventually constitute a high-quality forest resource. The objective of this study was to assess this potential using tree characteristics, forest structure and additional site and climatic conditions as predictors. A total of 145 trees were sampled in two areas located in the same bioclimatic zone. Lower-Saguenay-Charlevoix was chosen as an area where a restoration plan could be implemented, whereas Portneuf was selected as a reference. We used nonlinear mixed models to investigate which environmental factors are likely to influence the radial growth and stem quality of yellow birch sample trees. Our results suggest that topographic and climatic conditions, as well as the competitive environment of the trees, are important factors to consider in the evaluation of yellow birch production. Despite the limited occurrence of yellow birch, the potential for growth and quality was high in the Lower-Saguenay-Charlevoix area. For equivalent topographic, climatic, and competitive environment conditions, there was no significant difference in either radial growth or stem quality with Portneuf. We suggest that the economic interest of producing high quality timber should be used to justify the implementation of a restoration strategy in the Lower-Saguenay-Charlevoix area.

  7. Comprehensive transcriptome analysis of developing xylem responding to artificial bending and gravitational stimuli in Betula platyphylla.

    Directory of Open Access Journals (Sweden)

    Chao Wang

    Full Text Available Betula platyphylla Suk (birch is a fast-growing woody species that is important in pulp industries and the biofuels. However, as an important pulp species, few studies had been performed on its wood formation. In the present study, we investigated the molecular responses of birch xylem to artificial bending and gravitational stimuli. After trunks of birch trees were subjected to bending for 8 weeks, the cellulose content was significantly greater in tension wood (TW than in opposite wood (OW or normal wood (NW, whereas the lignin content in TW was significantly lower than that in OW and NW. In addition, TW grew more rapidly than OW and generated TW-specific fibers with an additional G-layer. Three transcriptome libraries were constructed from TW, OW and NW of B. platyphylla, respectively, after the plants were subjected to artificial bending. Overall, 80,909 nonredundant unigenes with a mean size of 768 nt were assembled. Expression profiles were generated, and 9,684 genes were found to be significantly differentially expressed among the TW, OW and NW libraries. These included genes involved in secondary cell wall structure, wood composition, and cellulose or lignin biosynthesis. Our study showed that during TW formation, genes involved in cellulose synthesis were induced, while the expression of lignin synthesis-related genes decreased, resulting in increased cellulose content and decreased lignin levels in TW. In addition, fasciclin-like arabinogalactan proteins play important role in TW formation. These findings may provide important insights into wood formation at the molecular level.

  8. Exogenous GA3 Application Enhances Xylem Development and Induces the Expression of Secondary Wall Biosynthesis Related Genes in Betula platyphylla

    Directory of Open Access Journals (Sweden)

    Huiyan Guo

    2015-09-01

    Full Text Available Gibberellin (GA is a key signal molecule inducing differentiation of tracheary elements, fibers, and xylogenesis. However the molecular mechanisms underlying the effect of GA on xylem elongation and secondary wall development in tree species remain to be determined. In this study, Betula platyphylla (birch seeds were treated with 300 ppm GA3 and/or 300 ppm paclobutrazol (PAC, seed germination was recorded, and transverse sections of hypocotyls were stained with toluidine blue; the two-month-old seedlings were treated with 50 μM GA3 and/or 50 μM PAC, transverse sections of seedling stems were stained using phloroglucinol–HCl, and secondary wall biosynthesis related genes expression was analyzed by real-time quantitative PCR. Results indicated that germination percentage, energy and time of seeds, hypocotyl height and seedling fresh weight were enhanced by GA3, and reduced by PAC; the xylem development was wider in GA3-treated plants than in the control; the expression of NAC and MYB transcription factors, CESA, PAL, and GA oxidase was up-regulated during GA3 treatment, suggesting their role in GA3-induced xylem development in the birch. Our results suggest that GA3 induces the expression of secondary wall biosynthesis related genes to trigger xylogenesis in the birch plants.

  9. Global chaos synchronization of coupled parametrically excited pendula

    Indian Academy of Sciences (India)

    O I Olusola; U E Vincent; A N Njah

    2009-12-01

    In this paper, we study the synchronization behaviour of two linearly coupled parametrically excited chaotic pendula. The stability of the synchronized state is examined using Lyapunov stability theory and linear matrix inequality (LMI); and some sufficient criteria for global asymptotic synchronization are derived from which an estimated critical coupling is determined. Numerical solutions are presented to verify the theoretical analysis. We also examined the transition to stable synchronous state and show that this corresponds to a boundary crisis of the chaotic attractor.

  10. 转基因白桦杂种T1代的生长发育及AP1基因的遗传分析%Growth and developmental analysis of T1 generation from BpAP1 transgenic birch

    Institute of Scientific and Technical Information of China (English)

    王朔; 黄海娇; 杨光; 姜静; 刘桂丰

    2016-01-01

    Woody plants are characterized by long developing period and high heterozygosity. It is important to shorten the life cycle of trees in tree breeding. APETALA1 (AP1) is a member of MADS-box gene family involved in flower development in plants. Overexpression of AP1 genes induces early flowering in transgenic plants. In order to investigate the genetic stability and regularity of foreign BpAP1 gene in BpAP1 transgenic birch, we generated T1 generation seedlings using three 35S BpAP1 transgenic plants and one wild-type plant as male parents, and three wild-type birch, Betula platyphylla í Betula pendula, as female parents. The growth, development and flowering characteristics of the T1 generation seedlings were analyzed. The results indicated that the foreign BpAP1 slightly influenced the pollen vitality of transgenic plants. About 36% -58% of T1 generation inherited the foreign BpAP1 gene from their parents. Chi-square test of BpAP1 gene segregation ratios revealed that BpAP1 was inherited in accordance with Mendelian inheritance. T1 generation seedlings carrying BpAP1 gene inherited the characteristics of early flowering and dwarfism from their male parent. The average heights of 1-and 2-year-old T1 generation seedlings carrying BpAP1 gene were significantly shorter than the progeny from hybridization of wild-type birch with the percentages of 44. 19% and 18. 92%, respectively. The phenotypes of T1 generation birch carrying foreign BpAP1 gene were quite different from the ones that were lack of foreign BpAP1 gene. According to the different phenotypes, we can infer whether the T1 generation seedlings carry BpAP1 gene or not. Our study proved that the exogenous AP1 gene can be stably inherited by sexual reproduction, and the acquired transgenic birch lines exhibited accelerated flowering time and a shortened juvenile phase, indicating that it can be used as parent materials for genetic studies on birch traits.%本文以3株野生型白桦为母本、3株35S

  11. Coupled Inverted Pendula Model of Competition and Cooperation

    Science.gov (United States)

    Yoshida, Katsutoshi; Ohta, Hiroki

    A coupled inverted pendula model of competition and cooperation is proposed to develop a purely mechanical implementation comparable to the Lotka-Volterra competition model. It is shown numerically that the proposed model can produce the four stable equilibriums analogous to ecological coexistence, two states of dominance, and scramble. The authors also propose two types of open-loop strategies to switch the equilibriums. The proposed strategies can be associated with an attack and a counter attack of agents through a metaphor of martial arts.

  12. Reproductive strategies and seeds behavior of Betula platyphylla Suk. population

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    By the methods of morphological anatomy and investigation in the sample fields, the main studies were carried out such as morphological anatomy of reproductive organs, birch population's reproductive ages, reproductive allotment value and seed behavior. The relationship between birch population and their surroundings was studied. The results showed that birch's flower organs and its seeds were suitable well for spreading by wind. The seeds by wind can fly far away in a short time. The quantity of seed spreading greatly varied with different communities. Birch's reproduction age can be changed in different ecological surroundings. The reproductive allotment value of birch was obviously different at different reproductive stages. In the mesic habitat, birch can grow well. The lowest reproductive age of them was 12, average age 15. In most cases the age of branches to bearing fruits was more than 18. The order of reproductive allotment values was as follows: a flowering phase > flower bud phase > fruit phase.

  13. Genetic Relationships among Prunus mume var. pendula Using AFLP Markers

    Institute of Scientific and Technical Information of China (English)

    Ming Jun; Zhang Qixiang; Ru Guangxin; Mao Qingshan; Yan Xiaolan; Lan Yanping

    2003-01-01

    Genetic relationships among Prunus mume var. pendula were studied by using AFLP markers. 18 accessions representing 14 cultivars ofPrunus murne var. pendula were selected from the germplasm collection at the Research Center of China Mci Flower. Seven Mse I-EcoR I AFLP primer combinations revealed 450 legible bands, and 269 of which were polymorphic markers. A similarity matrix was prepared using the simple matching coefficient of similarity and Nei's (72) distance coefficient. A UPGMA dendrogram demonstrated the genetic relationships of the cultivars. The information given by AFLP markers was basically consistent with the morphological classification and the evolutionary history of the morphotypes, and roughly supported the new revised classification system for Chinese Mci Cultivars. But there were still several exceptions: 1) the 'Guhong Chuizhi' inserted between the 'Tiaoxue Chuizhi' and the 'Danfen Chuizhi'; 2) the 'Wufu Chuizhi' kept off the Pink Pendant Form, and the 'Moshan Chuizhi' was removed from Viridiflora Pendant Form; 3) the 'Danbi Chuizhi' and the 'Shuangbi Chuizhi' of Viridiflora Pendant Form got together well but fell within the Pink Pendant Form.

  14. Rainfall redistribution of a virgin Pinus koraiensis forest and secondary Betula platyphylla forest in Northeast China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A virgin Pinus koraiensis forest in the Xiao-xing'an Mountains was selected to study its rainfall redistribution effect via 97 rainfall occurrences during a growing season.The following results were obtained:1) The canopy interception of the P.koraiensis virgin forest amounted to 98168 mm during a growing season (May to September),which was 19.6 per cent of the total rainfall and 1.3 times that of a secondary Betula platyphylla forest.Compared with other forest types in China (11.4%-36.5%),the ratio of the canopy interception in the virgin pine forest was at a medium level.2) The throughfall of the virgin pine forest was 395.77 mm,which accounted for 78.7% of total precipitation,and the stem-flow was 8.78 mm,accounting for 1.74% of total precipitation.Compared with the secondary birch forest,the virgin pine forest had lower throughfall but higher stem-flow.3) Cubic regression equations (p < 0.01)which describe the relation between throughfall,stem-flow and canopy interception in the virgin pine forest and rainfall in an open field were fitted.A linear regression equation (p < 0.01) was found to be a better fit for the relationship between throughfall of the secondary birch forest and rainfall outside the forest.Factors affecting throughfall and stem-flow were analyzed,with results providing a good reference to the study of rainfall redistribution in coniferous and broadleaved mixed forests.

  15. Chaos suppression and desynchronization phenomena in periodically coupled pendula subjected to localized heterogeneous forces

    Energy Technology Data Exchange (ETDEWEB)

    Chacon, R. [Departamento de Fisica Aplicada, Escuela de Ingenierias Industriales, Universidad de Extremadura, Apartado Postal 382, E-06071 Badajoz (Spain)], E-mail: rchacon@unex.es; Martinez, P.J. [Departamento de Fisica Aplicada, E.U.I.T.I., Universidad de Zaragoza, Spain and Instituto de Ciencia de Materiales de Aragon, CSIC-Universidad de Zaragoza, E-50009 Zaragoza (Spain); Martinez, J.A. [Departamento de Ingenieria Electrica, Electronica y Automatica, E.P.S., Universidad de Castilla-La Mancha, E-02071 Albacete (Spain); Lenci, S. [Dipartimento di Architettura, Costruzioni e Strutture, Universita Politecnica delle Marche, via Brecce Bianche, 60131 Ancona (Italy)

    2009-11-30

    The suppressory effects of localized heterogeneous periodic pulses on the chaotic behaviour of sinusoidally coupled nonlinear pendula are studied. We assume that when the pendula are driven synchronously, i.e., all driving pulses have the same waveform, the chains display chaotic dynamics. It is shown that decreasing the impulse transmitted by the pulses of a minimal number of pendula results in regularization with the whole array exhibiting frequency synchronization over a wide range of coupling periods. These findings demonstrate that decreasing the impulse transmitted by localized external forces can tame chaos and lead to frequency-locked states in networks of periodically coupled dissipative systems.

  16. [Oral allergy syndrome among patients with birch pollinosis in Sapporo].

    Science.gov (United States)

    Yamamoto, Tetsuo; Asakura, Kohji; Shirasaki, Hideaki; Himi, Tetsuo; Ogasawara, Hideki; Narita, Shin-Ichirou; Kataura, Akikatsu

    2004-04-01

    We evaluated the relationships between oral and pharyngeal hypersensitivity to fruits and vegetables (oral allergy syndrome) and birch pollinosis in 2003 in Sapporo. 1. Of 153 patients with birch pollinosis (seasonal nasal or ocular symptom and CAP positive [birch pollen CAP score 2 or more]), 65 patients (42%) have episode of oral allergy syndrome (OAS). And that rate in 2003 was higher than in 1992 and was equal to in 1998. 2. Among birch pollinosis patients, the higher the CAP score of birch pollen, the higher the prevalences of OAS were found to be. 3. Among birch pollinosis patients, female have OAS much more than male. 4. Among birch pollinosis patients in 1998, patients who visited to ENT clinic for medical consultation of birch pollinosis in March and April have OAS much more than patients who visited in May and June.

  17. ANTIBIOTIC RESISTANCE OF ESCHERICHIA COLI ISOLATED FROM UKRAINIAN BETULA VERRUCOSA EHRH. POLLEN AFTER MICROBIOLOGICAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Tetiana Shevtsova

    2013-08-01

    Full Text Available Seven samples of silver birch pollen from different habitat of Ukraine were investigated in order to estimate their contamination with the Enterobacteriaceae family, anaerobic bacteria and fungi. Also resistance of 108 strains of Escherichia coli isolated from seven samples of Ukrainian Betula verrucosa Ehrh. pollen against 5 antibiotics: ampicillin, chloramphenicol, meropenem, ceftriaxone and ofloxacin were determined. Disc diffusion method was used for antibiotic suceptibility testing according to EUCAST 2012. It is established the concentrations of enterobacteria ranged from 0.00 to 4.16 log cfu/g, of anaerobic bacteria – 2.48 to 4.90 log cfu/g and concentration of fungi ranged from 2.48 to 4.14 log cfu/g. Degree of pollen contamination is different depending on the habitats. The resistance of E. coli isolates was determined against ampicillin, chloramphenicol, meropenem and ofloxacin. But intermediate resistance in the 33.3% of E. coli isolates and susceptibility in the 8.3% to ceftriaxone was found out. Antibiotic resistance was evaluated for all samples of pollen in whole.

  18. Experimental multistable states for small network of coupled pendula

    Science.gov (United States)

    Dudkowski, Dawid; Grabski, Juliusz; Wojewoda, Jerzy; Perlikowski, Przemyslaw; Maistrenko, Yuri; Kapitaniak, Tomasz

    2016-07-01

    Chimera states are dynamical patterns emerging in populations of coupled identical oscillators where different groups of oscillators exhibit coexisting synchronous and incoherent behaviors despite homogeneous coupling. Although these states are typically observed in the large ensembles of oscillators, recently it has been shown that so-called weak chimera states may occur in the systems with small numbers of oscillators. Here, we show that similar multistable states demonstrating partial frequency synchronization, can be observed in simple experiments with identical mechanical oscillators, namely pendula. The mathematical model of our experiment shows that the observed multistable states are controlled by elementary dynamical equations, derived from Newton’s laws that are ubiquitous in many physical and engineering systems. Our finding suggests that multistable chimera-like states are observable in small networks relevant to various real-world systems.

  19. Parkia pendula lectin as histochemistry marker for meningothelial tumour

    Directory of Open Access Journals (Sweden)

    EIC Beltrão

    2009-06-01

    Full Text Available Lectins have been intensively used in histochemical techniques for cell surface characterization. These proteins are involved in several biological processes and their use as histochemical markers have been evaluated since they can indicate differences in cell surfaces. Parkia pendula lectin (PpeL was evaluated as histochemical marker for meningothelial meningioma biopsies. Tissue slices were incubated with PpeL conjugated to horseradish peroxidase (PpeL-HRP and Concanavalin A-HRP (ConA-HPR and the binding visualized with diaminobenzidine and hydrogen peroxide. The lectin-tissue binding was inhibited with D-glucose. PpeL showed to be a useful tool for the characterization of meningothelial tumour and clinico-pathological diagnosis.

  20. Twelve Elastic Constants of Betula platyphylla Suk.

    Institute of Scientific and Technical Information of China (English)

    Wang Liyu; Lu Zhenyou

    2004-01-01

    Wood elastic constants are needed to describe the elastic behaviors of wood and be taken as an important design parameter for wood-based composite materials and structural materials. This paper clarified the relationships between compliance coefficients and engineering elastic constants combined with orthotropic properties of wood, and twelve elastic constants of Betula platyphylla Suk. were measured by electrical strain gauges. Spreading the adhesive quantity cannot be excessive or too little when the strain flakes were glued. If excessive, the glue layer was too thick which would influence the strain flakes' performance, and if too little, glues plastered were not firm, which could not accurately transmit the strain. Wood as an orthotropic material, its modulus of elasticity and poisson's ratios are related by two formulas:μij /Ei =μji /Ej and μij 0.95) between the reciprocal of elastic modulus MOE-1 and the square of the ratio of depth to length (h/l)2, which indicate that shear modulus values measured were reliable by three point bending experiment.

  1. A phytosociological study on Betula Platyphylla forests in Daxing’an Mountains of China

    Institute of Scientific and Technical Information of China (English)

    杨永富; 侯丽君; 魏占才; 宋关玲

    2000-01-01

    For the first time in this paper the forests of Betula platyphylla in Daxing’an Mountains are subdivided by phytosociological methods. Three community types of B. platyphylla forest have been differentiated, e.g., Rhododendron dahuricum-Betula platyphylla community, Corylus heterophylla-Betula platyphylla community and Artemisia stolonifera-Betula platyphylla community. The distributed elevation, stand height, differential species, major composition species of tree layer, shrub layer and herb layer for each community were detail described

  2. Quantitative DNA Analyses for Airborne Birch Pollen.

    Directory of Open Access Journals (Sweden)

    Isabell Müller-Germann

    Full Text Available Birch trees produce large amounts of highly allergenic pollen grains that are distributed by wind and impact human health by causing seasonal hay fever, pollen-related asthma, and other allergic diseases. Traditionally, pollen forecasts are based on conventional microscopic counting techniques that are labor-intensive and limited in the reliable identification of species. Molecular biological techniques provide an alternative approach that is less labor-intensive and enables identification of any species by its genetic fingerprint. A particularly promising method is quantitative Real-Time polymerase chain reaction (qPCR, which can be used to determine the number of DNA copies and thus pollen grains in air filter samples. During the birch pollination season in 2010 in Mainz, Germany, we collected air filter samples of fine (<3 μm and coarse air particulate matter. These were analyzed by qPCR using two different primer pairs: one for a single-copy gene (BP8 and the other for a multi-copy gene (ITS. The BP8 gene was better suitable for reliable qPCR results, and the qPCR results obtained for coarse particulate matter were well correlated with the birch pollen forecasting results of the regional air quality model COSMO-ART. As expected due to the size of birch pollen grains (~23 μm, the concentration of DNA in fine particulate matter was lower than in the coarse particle fraction. For the ITS region the factor was 64, while for the single-copy gene BP8 only 51. The possible presence of so-called sub-pollen particles in the fine particle fraction is, however, interesting even in low concentrations. These particles are known to be highly allergenic, reach deep into airways and cause often severe health problems. In conclusion, the results of this exploratory study open up the possibility of predicting and quantifying the pollen concentration in the atmosphere more precisely in the future.

  3. Quantitative DNA Analyses for Airborne Birch Pollen.

    Science.gov (United States)

    Müller-Germann, Isabell; Vogel, Bernhard; Vogel, Heike; Pauling, Andreas; Fröhlich-Nowoisky, Janine; Pöschl, Ulrich; Després, Viviane R

    2015-01-01

    Birch trees produce large amounts of highly allergenic pollen grains that are distributed by wind and impact human health by causing seasonal hay fever, pollen-related asthma, and other allergic diseases. Traditionally, pollen forecasts are based on conventional microscopic counting techniques that are labor-intensive and limited in the reliable identification of species. Molecular biological techniques provide an alternative approach that is less labor-intensive and enables identification of any species by its genetic fingerprint. A particularly promising method is quantitative Real-Time polymerase chain reaction (qPCR), which can be used to determine the number of DNA copies and thus pollen grains in air filter samples. During the birch pollination season in 2010 in Mainz, Germany, we collected air filter samples of fine (<3 μm) and coarse air particulate matter. These were analyzed by qPCR using two different primer pairs: one for a single-copy gene (BP8) and the other for a multi-copy gene (ITS). The BP8 gene was better suitable for reliable qPCR results, and the qPCR results obtained for coarse particulate matter were well correlated with the birch pollen forecasting results of the regional air quality model COSMO-ART. As expected due to the size of birch pollen grains (~23 μm), the concentration of DNA in fine particulate matter was lower than in the coarse particle fraction. For the ITS region the factor was 64, while for the single-copy gene BP8 only 51. The possible presence of so-called sub-pollen particles in the fine particle fraction is, however, interesting even in low concentrations. These particles are known to be highly allergenic, reach deep into airways and cause often severe health problems. In conclusion, the results of this exploratory study open up the possibility of predicting and quantifying the pollen concentration in the atmosphere more precisely in the future.

  4. Three New Clerodane Diterpenes from Polyalthia longifolia var. pendula

    Directory of Open Access Journals (Sweden)

    Tung-Ho Wu

    2014-02-01

    Full Text Available Three new clerodane diterpenes, (4→2-abeo-cleroda-2,13E-dien-2,14-dioic acid (1, (4→2-abeo-2,13-diformyl-cleroda-2,13E-dien-14-oic acid (2, and 16(R&S- methoxycleroda-4(18,13-dien-15,16-olide (3, were isolated from the unripe fruit of Polyalthia longifolia var. pendula (Annonaceae together with five known compounds (4–8. The structures of all isolates were determined by spectroscopic analysis. The anti-inflammatory activity of the isolates was evaluated by testing their inhibitory effect on NO production in LPS-stimulated RAW 264.7 macrophages. Among the isolated compounds, 16-hydroxycleroda-3,13-dien-15,16-olide (6 and 16-oxocleroda-3,13-dien-15-oic acid (7 showed promising NO inhibitory activity at 10 µg/mL, with 81.1% and 86.3%, inhibition, respectively.

  5. Genome-scale transcriptome analysis in response to nitric oxide in birch cells: implications of the triterpene biosynthetic pathway.

    Directory of Open Access Journals (Sweden)

    Fansuo Zeng

    Full Text Available Evidence supporting nitric oxide (NO as a mediator of plant biochemistry continues to grow, but its functions at the molecular level remains poorly understood and, in some cases, controversial. To study the role of NO at the transcriptional level in Betula platyphylla cells, we conducted a genome-scale transcriptome analysis of these cells. The transcriptome of untreated birch cells and those treated by sodium nitroprusside (SNP were analyzed using the Solexa sequencing. Data were collected by sequencing cDNA libraries of birch cells, which had a long period to adapt to the suspension culture conditions before SNP-treated cells and untreated cells were sampled. Among the 34,100 UniGenes detected, BLASTX search revealed that 20,631 genes showed significant (E-values≤10-5 sequence similarity with proteins from the NR-database. Numerous expressed sequence tags (i.e., 1374 were identified as differentially expressed between the 12 h SNP-treated cells and control cells samples: 403 up-regulated and 971 down-regulated. From this, we specifically examined a core set of NO-related transcripts. The altered expression levels of several transcripts, as determined by transcriptome analysis, was confirmed by qRT-PCR. The results of transcriptome analysis, gene expression quantification, the content of triterpenoid and activities of defensive enzymes elucidated NO has a significant effect on many processes including triterpenoid production, carbohydrate metabolism and cell wall biosynthesis.

  6. The role of summer precipitation and summer temperature in establishment and growth of dwarf shrub Betula nana in northeast Siberian tundra

    DEFF Research Database (Denmark)

    Li, Bingxi; Heijmans, Monique M P D; Berendse, Frank;

    2016-01-01

    It is widely believed that deciduous tundra-shrub dominance is increasing in the pan-Arctic region, mainly due to rising temperature. We sampled dwarf birch (Betula nana L.) at a northeastern Siberian tundra site and used dendrochronological methods to explore the relationship between climatic...... variables and local shrub dominance. We found that establishment of shrub ramets was positively related to summer precipitation, which implies that the current high dominance of B. nana at our study site could be related to high summer precipitation in the period from 1960 to 1990. The results confirmed...... that early summer temperature is most influential to annual growth rates of B. nana. In addition, summer precipitation stimulated shrub growth in years with warm summers, suggesting that B. nana growth may be co-limited by summer moisture supply. The dual controlling role of temperature and summer...

  7. Large-Scale Variations in Lumber Value Recovery of Yellow Birch and Sugar Maple in Quebec, Canada.

    Directory of Open Access Journals (Sweden)

    Mariana Hassegawa

    Full Text Available Silvicultural restoration measures have been implemented in the northern hardwoods forests of southern Quebec, Canada, but their financial applicability is often hampered by the depleted state of the resource. To help identify sites most suited for the production of high quality timber, where the potential return on silvicultural investments should be the highest, this study assessed the impact of stand and site characteristics on timber quality in sugar maple (Acer saccharum Marsh. and yellow birch (Betula alleghaniensis Britt.. For this purpose, lumber value recovery (LVR, an estimate of the summed value of boards contained in a unit volume of round wood, was used as an indicator of timber quality. Predictions of LVR were made for yellow birch and sugar maple trees contained in a network of more than 22000 temporary sample plots across the Province. Next, stand-level variables were selected and models to predict LVR were built using the boosted regression trees method. Finally, the occurrence of spatial clusters was verified by a hotspot analysis. Results showed that in both species LVR was positively correlated with the stand age and structural diversity index, and negatively correlated with the number of merchantable stems. Yellow birch had higher LVR in areas with shallower soils, whereas sugar maple had higher LVR in regions with deeper soils. The hotspot analysis indicated that clusters of high and low LVR exist across the province for both species. Although it remains uncertain to what extent the variability of LVR may result from variations in past management practices or in inherent site quality, we argue that efforts to produce high quality timber should be prioritized in sites where LVR is predicted to be the highest.

  8. 欧洲白桦无性系苗期光合特性的比较%Studies on photosynthetic characteristics of Betula pendula×B.pendula var.carelica Sok

    Institute of Scientific and Technical Information of China (English)

    张军; 柴永江; 杨敏生

    2006-01-01

    对2种栽培条件下欧洲白桦优良无性系1/86、2/86和本地白桦的净光合速率、蒸腾速率及相关生理指标进行了测定.结果表明:在净光合速率方面,田间栽培和盆栽方式下的本地白桦明显高于1/86、2/86,而 1/86、2/86之间则没有明显差异;田间栽培下的3种白桦相应高于盆栽条件下的净光合速率.在蒸腾速率方面,田间栽培条件下的3个白桦品种之间没有明显差异;盆栽条件下的本地白桦显著高于1/86、2/86, 而1/86、2/86之间则没有差异;田间栽培下的1/86、2/86明显高于盆栽的蒸腾速率,而本地白桦在2种栽培方式下没有差异.

  9. Quantification of C uptake in subarctic birch forest after setback by an extreme insect outbreak

    Science.gov (United States)

    Heliasz, Michal; Johansson, Torbjörn; Lindroth, Anders; Mölder, Meelis; Mastepanov, Mikhail; Friborg, Thomas; Callaghan, Terry V.; Christensen, Torben R.

    2011-01-01

    The carbon dynamics of northern natural ecosystems contribute significantly to the global carbon balance. Periodic disturbances to these dynamics include insect herbivory. Larvae of autumn and winter moths (Epirrita autumnata and Operophtera brumata) defoliate mountain birch (Betula pubescens) forests in northern Scandinavia cyclically every 9-10 years and occasionally (50-150 years) extreme population densities can threaten ecosystem stability. Here we report impacts on C balance following a 2004 outbreak where a widespread area of Lake Torneträsk catchment was severely defoliated. We show that in the growing season of 2004 the forest was a much smaller net sink of C than in a reference year, most likely due to lower gross photosynthesis. Ecosystem respiration in 2004 was smaller and less sensitive to air temperature at nighttime relative to 2006. The difference in growing season uptake between an insect affected and non-affected year over the 316 km2 area is in the order of 29 × 103 tonnes C equal to a reduction of the sink strength by 89%.

  10. The Banyan and the Birch Tree

    DEFF Research Database (Denmark)

    Lorenzen, Mark; Taeube, Florian A.

    Theoretical and empirical research on entrepreneurial networks is largely outcome-oriented and little integrated with family firm research. In this paper, we draw on social network and entrepreneurship literatures in order to investigate how family businesses build and make use of a variety...... is higher than predictions in the theoretical literature and empirical findings in cross-country studies suggest. Moreover, we show that the ‘Indian' family is an institution that dominates embedded ties. The Banyan tree symbolizes this interconnectedness of the different branches of an Indian family...... compared to the plain structure of a birch tree describing Hollywood, where embedded ties can be different from familial ties....

  11. Effects of soil type, fertilization and drought on carbon allocation to root growth and partitioning between secondary metabolism and ectomycorrhizae of Betula papyrifera.

    Science.gov (United States)

    Kleczewski, Nathan M; Herms, Daniel A; Bonello, Pierluigi

    2010-07-01

    Paper birch (Betula papyrifera Marsh) seedlings were grown in a greenhouse in either subsoil or topsoil in factorial combination with two fertilization and drought regimes to investigate how different soil environments and nutrient availability drive belowground partitioning between growth, secondary metabolism and ectomycorrhizal (EM) associations, and impact drought tolerance of paper birch. Root and total seedling dry biomass, starch, soluble sugars, soluble phenolics, lignin and EM abundance were quantified. In unfertilized topsoil, total plant biomass and root biomass were approximately nine times higher than in unfertilized subsoil, but the root weight ratios did not differ between soils. Root soluble phenolics and lignin were higher in unfertilized subsoil than in unfertilized topsoil, whereas EM abundance was significantly higher in unfertilized topsoil than in unfertilized subsoil. In topsoil, fertilization decreased root biomass and EM abundance and increased root phenolics and lignin. In contrast, fertilization of subsoil increased root biomass but decreased root phenolics and lignin, while EM abundance was unaffected. In both soil types, fertilization reduced root weight ratios. Across soil types, EM abundance was negatively correlated with root soluble sugars, root phenolics and lignin, but this was driven mainly by the responses in the topsoil treatment. Our results show that soil fertility mediates carbon tradeoffs among defense, growth and EM associations.

  12. BIRCH: A user-oriented, locally-customizable, bioinformatics system

    Directory of Open Access Journals (Sweden)

    Fristensky Brian

    2007-02-01

    Full Text Available Abstract Background Molecular biologists need sophisticated analytical tools which often demand extensive computational resources. While finding, installing, and using these tools can be challenging, pipelining data from one program to the next is particularly awkward, especially when using web-based programs. At the same time, system administrators tasked with maintaining these tools do not always appreciate the needs of research biologists. Results BIRCH (Biological Research Computing Hierarchy is an organizational framework for delivering bioinformatics resources to a user group, scaling from a single lab to a large institution. The BIRCH core distribution includes many popular bioinformatics programs, unified within the GDE (Genetic Data Environment graphic interface. Of equal importance, BIRCH provides the system administrator with tools that simplify the job of managing a multiuser bioinformatics system across different platforms and operating systems. These include tools for integrating locally-installed programs and databases into BIRCH, and for customizing the local BIRCH system to meet the needs of the user base. BIRCH can also act as a front end to provide a unified view of already-existing collections of bioinformatics software. Documentation for the BIRCH and locally-added programs is merged in a hierarchical set of web pages. In addition to manual pages for individual programs, BIRCH tutorials employ step by step examples, with screen shots and sample files, to illustrate both the important theoretical and practical considerations behind complex analytical tasks. Conclusion BIRCH provides a versatile organizational framework for managing software and databases, and making these accessible to a user base. Because of its network-centric design, BIRCH makes it possible for any user to do any task from anywhere.

  13. 75 FR 51987 - Birch Power Company and Sorenson Engineering; Birch Power Company and Sorenson Leasing L.L.C...

    Science.gov (United States)

    2010-08-24

    ... Sorenson Leasing L.L.C.; Notice of Application for Transfer of License, and Soliciting Comments and Motions... (transferors) and Birch Power Company and Sorenson Leasing, L.L.C. (transferees) filed an application for..., Birch Power Company, Sorenson Engineering, and Sorenson Leasing L.L.C., 5203 South 11th East,...

  14. Molecular Ice Nucleation Activity of Birch Pollen

    Science.gov (United States)

    Felgitsch, Laura; Bichler, Magdalena; Häusler, Thomas; Weiss, Victor U.; Marchetti-Deschmann, Martina; Allmaier, Günter; Grothe, Hinrich

    2015-04-01

    Heterogeneous ice nucleation plays a major part in ecosystem and climate. Due to the triggering of ice cloud formation it influences the radiation balance of the earth, but also on the ground it can be found to be important in many processes of nature. So far the process of heterogeneous ice nucleation is not fully understood and many questions remain to be answered. Biological ice nucleation is hereby from great interest, because it shows the highest freezing temperatures. Several bacteria and fungi act as ice nuclei. A famous example is Pseudomonas syringae, a bacterium in commercial use (Snomax®), which increases the freezing from homogeneous freezing temperatures of approx. -40° C (for small volumes as in cloud droplets) to temperatures up to -2° C. In 2001 it was found that birch pollen can trigger ice nucleation (Diehl et al. 2001; Diehl et al. 2002). For a long time it was believed that this is due to macroscopic features of the pollen surface. Recent findings of Bernhard Pummer (2012) show a different picture. The ice nuclei are not attached on the pollen surface directly, but on surface material which can be easily washed off. This shows that not only the surface morphology, but also specific molecules or molecular structures are responsible for the ice nucleation activity of birch pollen. With various analytic methods we work on elucidating the structure of these molecules as well as the mechanism with which they trigger ice nucleation. To solve this we use various instrumental analytic techniques like Nuclear Magnetic Resonance spectroscopy (NMR), Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS), and Gas-phase Electrophoretic Mobility Molecular Analysis (GEMMA). Also standard techniques like various chromatographic separation techniques and solvent extraction are in use. We state here that this feature might be due to the aggregation of small molecules, with agglomerates showing a specific surface structure. Our results

  15. Multi-Nested Pendula: a new concept for vibration isolation and its application to gravitational wave detectors

    CERN Document Server

    Aguiar, Odylio D

    2013-01-01

    Adequate vibration isolation is of great importance for the design of any sensitive experiment measuring mechanical motions. The so-called multistage or multipole mechanical low pass filter is a common artifact used for the construction of highly effective vibration isolation. However, the problem with it is the vertical clearance needed inside the vacuum chambers for the construction of numerous, long pendulum stages necessary for effective horizontal vibration isolation. The purpose of this work is to introduce a new concept, called the multi-nested pendula concept, which solves this problem. The attenuation performance of an ideal multistage nested pendula filter is better than that of an ideal multistage common equal pendula filter by a factor of N^{N}, where N is the number of stages used, making this idea of a multi-nested pendula a very interesting one. The initial results (of stability and system resonances) measured for a prototype reinforce the viability of the practical implementation of such idea....

  16. Methods for estimating production and utilization of paper birch saplings

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Development of technique to estimate browse production and utilization. Developed a set of methods for estimating annual production and utilization of paper birch...

  17. Food allergy to apple and specific immunotherapy with birch pollen

    DEFF Research Database (Denmark)

    Hansen, Kirsten Skamstrup; Khinchi, Marianne Søndergaard; Skov, Per Stahl

    2004-01-01

    Conflicting results concerning the effect of specific pollen immunotherapy (SIT) on allergy to plant foods have been reported. The aim of this study was to investigate the effect of SIT using a birch pollen extract on food allergy with focus on allergy to apple. Seventy-four birch pollen......-allergic patients were included in a double-blind, double-dummy, and placebo-controlled comparison of sublingual-swallow (SLIT) and subcutaneous (SCIT) administration of a birch pollen extract. Sixty-nine percent of these patients reported allergy to apple. The clinical reactivity to apple was evaluated by open....... Therefore, oral allergy syndrome (OAS) to apple should not be considered as a main criterion for selecting patients for birch pollen immunotherapy at present....

  18. 16 Pollen Allergens Differ From Nonallergenic Pollen Proteins by Their Lower Extent of Evolutionary Conservation

    OpenAIRE

    Radauer, Christian; Guhslc, Eva; Bublin, Merima; Breiteneder, Heimo

    2012-01-01

    Background Pollen contains hundreds of different proteins. However, only a small fraction of them have been identified to be allergenic. We aimed to test the hypothesis that most pollen proteins are non-allergenic due to their high extent of sequence conservation among non-related species. Methods Data on the composition of pollen proteomes of birch (Betula pendula), pellitory (Parientaria judaica) and timothy grass (Phleum pratense) were obtained from the literature. Sequences were downloade...

  19. USSR Report, Chemistry.

    Science.gov (United States)

    2007-11-02

    determined photocolorimetrically using vanillin reagent, on ethanol extracts of bark which were cleaned up on polyamide. The highest catechin content...Jul 84) 39 Artificial Graphite, Production and Properties (A.’ D. Kokurin; ZHURNAL PRIKLADNOY KHIMII, No 9, Sep 84) 40 Step-Wise Extraction ...Birch Wood (L. K. Molotkov; KHIMIYA DREVESINY, No 5, Sep-Oct 84).... 109 Catechin Content of Birth (Betula Pendula Roth.) Bark in Relation to Climatic

  20. Quasiperiodically forced damped pendula and Schroedinger equations with quasiperiodic potentials - Implications of their equivalence

    Science.gov (United States)

    Bondeson, A.; Ott, E.; Antonsen, T. M., Jr.

    1985-01-01

    Certain first-order nonlinear ordinary differential equations exemplified by strongly damped, quasiperiodically driven pendula and Josephson junctions are isomorphic to Schroedinger equations with quasiperiodic potentials. The implications of this equivalence are discussed. In particular, it is shown that the transition to Anderson localization in the Schroedinger problem corresponds to the occurrence of a novel type of strange attractor in the pendulum problem. This transition should be experimentally observable in the frequency spectrum of the pendulum of Josephson junction.

  1. Leaf and canopy conductance in aspen and aspen-birch forests under free-air enrichment of carbon dioxide and ozone.

    Science.gov (United States)

    Uddling, Johan; Teclaw, Ronald M; Pregitzer, Kurt S; Ellsworth, David S

    2009-11-01

    Increasing concentrations of atmospheric carbon dioxide (CO2) and tropospheric ozone (O3) have the potential to affect tree physiology and structure, and hence forest feedbacks on climate. Here, we investigated how elevated concentrations of CO2 (+45%) and O3 (+35%), alone and in combination, affected conductance for mass transfer at the leaf and canopy levels in pure aspen (Populus tremuloides Michx.) and in mixed aspen and birch (Betula papyrifera Marsh.) forests in the free-air CO2-O3 enrichment experiment near Rhinelander, Wisconsin (Aspen FACE). The study was conducted during two growing seasons, when steady-state leaf area index (L) had been reached after > 6 years of exposure to CO2- and O3-enrichment treatments. Canopy conductance (g(c)) was estimated from stand sap flux, while leaf-level conductance of sun leaves in the upper canopy was derived by three different and independent methods: sap flux and L in combination with vertical canopy modelling, leaf 13C discrimination methodology in combination with photosynthesis modelling and leaf-level gas exchange. Regardless of the method used, the mean values of leaf-level conductance were higher in trees growing under elevated CO2 and/or O3 than in trees growing in control plots, causing a CO2 x O3 interaction that was statistically significant (P aspen and mixed aspen-birch communities. These results demonstrate that short-term primary stomatal closure responses to elevated CO2 and O3 were completely offset by long-term cumulative effects of these trace gases on tree and stand structure in determining canopy- and leaf-level conductance in pure aspen and mixed aspen-birch forests. Our results, together with the findings from other long-term FACE experiments with trees, suggest that model assumptions of large reductions in stomatal conductance under rising atmospheric CO2 are very uncertain for forests.

  2. Comparative analyses of plastid and AFLP data suggest different colonization history and asymmetric hybridization between Betula pubescens and B. nana.

    Science.gov (United States)

    Eidesen, Pernille Bronken; Alsos, Inger Greve; Brochmann, Christian

    2015-08-01

    Birches (Betula spp.) hybridize readily, confounding genetic signatures of refugial isolation and postglacial migration. We aimed to distinguish hybridization from range-shift processes in the two widespread and cold-adapted species B. nana and B. pubescens, previously shown to share a similarly east-west-structured variation in plastid DNA (pDNA). We sampled the two species throughout their ranges and included reference samples of five other Betula species and putative hybrids. We analysed 901 individual plants using mainly nuclear high-resolution markers (amplified fragment length polymorphisms; AFLPs); a subset of 64 plants was also sequenced for two pDNA regions. Whereas the pDNA variation as expected was largely shared between B. nana and B. pubescens, the two species were distinctly differentiated at AFLP loci. In B. nana, both the AFLP and pDNA results corroborated the former pDNA-based hypothesis that it expanded from at least two major refugia in Eurasia, one south of and one east of the North European ice sheets. In contrast, B. pubescens showed a striking lack of geographic structuring of its AFLP variation. We identified a weak but significant increase in nuclear (AFLP) gene flow from B. nana into B. pubescens with increasing latitude, suggesting hybridization has been most frequent at the postglacial expansion front of B. pubescens and that hybrids mainly backcrossed to B. pubescens. Incongruence between pDNA and AFLP variation in B. pubescens can be explained by efficient expansion from a single large refugium combined with leading-edge hybridization and plastid capture from B. nana during colonization of new territory already occupied by this more cold-tolerant species.

  3. [Short-term death dynamics of trees in natural secondary poplar-birch forest in Changbai Mountains of Northeast China].

    Science.gov (United States)

    Zhang, Zhao-Chen; Hao, Zhan-Qing; Ye, Ji; Lin, Fei; Yuan, Zuo-Qiang; Xing, Ding-Liang; Shi, Shuai; Wang, Xu-gao

    2013-02-01

    Taking the 5 hm2 sampling plot in the natural secondary poplar-birch forest in Changbai Mountains as test object, and based on the two census data in 2005 and 2010, an analysis was made on the main tree species composition and quantity, size class distribution of dead individuals, and regeneration characteristics of the main tree species in different habitat types of the plot in 2005-2010. In the five years, the species number of the individuals with DBH> or = 1 cm increased from 46 to 47, among which, 3 species were newly appeared, and 2 species were disappeared. The number of the individuals changed from 16509 to 15027, among which, 2150 individuals died, accounting for 13% of the whole individuals in 2005, and 668 individuals were newly increased. The basal area of the trees increased from 28.79 m2.m-2 to 30.55 m2.m-2, with that of 41 species increased while that of 6 species decreased. The decrease of the basal area of Betula platyphylla and Populus davidiana accounted for 72.3% of the total decrease. Small individuals had higher mortality, as compared with large ones, and the mortality of the individuals with DBHDBH. No difference was observed in the tree mortality among different habitat types, but the mortality of the individuals with different size classes showed greater variation.

  4. Variability of some morphological traits of one-year old red oak, black walnut, birch and wild pear seedlings in the nurseries of Jastrebac region

    Directory of Open Access Journals (Sweden)

    Krstić Milun

    2002-01-01

    Full Text Available Five morphological and quantitative characteristics of one-year old seedlings of Red oak (Quercus rubra L, Black walnut (Juglans nigra L, Wild pear (Pyrus pygrowser Borkh and Birch (Betula verrucosa Ehrh were studied. The seedlings were produced and cultivated in the controlled conditions of the nursery in the region of Jastrebac, by the classical method. Aboveground seedling height, root collar diameter, root length, number of secondary roots and the leaf assimilation area were analysed. Intraspecific and interspecific variability of morphological features of the above species were assessed by the comparative analysis and statistical methods The comparative analysis shows the great individual variability of seedlings, which can indicate their genetic potential, adaptation to environment conditions, further spontaneous selection and the development in natural conditions. This justifies the need of the quality assessment and the first selection already in the nursery, in order to ensure the quality planting material and to reduce the risk of afforestation failure One-year old birch seedlings have the lowest average height (18.8 cm. Black walnut and Wild pear seedlings are approximately twice as high, and Red oak about 2.5 times higher. At the same time Red oak seedlings have for about one-fourth greater height than Black walnut, and for one-third greater height than Wild pear. Wild pear seedlings attain the averagely twice larger root collar diameter than Birch (2.8 cm, Red oak seedlings about 2.5 times larger diameter, and Black walnut 3.5 times larger diameter. Black walnut has a larger root collar diameter than Red oak for about one third, and almost twice larger than Wild pear. Birch, Red oak and Wild pear have almost twice longer root (1.8-1.9 times, Black walnut about 2.25 times longer. The total assimilation area of a Birch seedling is averagely 89.0 cm2. Compared to birch, wild pear has approximately double assimilation area per tree, Red

  5. Multi-Year Leaf-Level Response to Sub-Ambient and Elevated Experimental CO2 in Betula nana.

    Science.gov (United States)

    Hincke, Alexandra J C; Broere, Tom; Kürschner, Wolfram M; Donders, Timme H; Wagner-Cremer, Friederike

    2016-01-01

    The strong link between stomatal frequency and CO2 in woody plants is key for understanding past CO2 dynamics, predicting future change, and evaluating the significant role of vegetation in the hydrological cycle. Experimental validation is required to evaluate the long-term adaptive leaf response of C3 plants to CO2 conditions; however, studies to date have only focused on short-term single-season experiments and may not capture (1) the full ontogeny of leaves to experimental CO2 exposure or (2) the true adjustment of structural stomatal properties to CO2, which we postulate is likely to occur over several growing seasons. We conducted controlled growth chamber experiments at 150 ppmv, 450 ppmv and 800 ppmv CO2 with woody C3 shrub Betula nana (dwarf birch) over two successive annual growing seasons and evaluated the structural stomatal response to atmospheric CO2 conditions. We find that while some adjustment of leaf morphological and stomatal parameters occurred in the first growing season where plants are exposed to experimental CO2 conditions, amplified adjustment of non-plastic stomatal properties such as stomatal conductance occurred in the second year of experimental CO2 exposure. We postulate that the species response limit to CO2 of B. nana may occur around 400-450 ppmv. Our findings strongly support the necessity for multi-annual experiments in C3 perennials in order to evaluate the effects of environmental conditions and provide a likely explanation of the contradictory results between historical and palaeobotanical records and experimental data.

  6. Birch Creek, Alaska, a wild and scenic river analysis: Preliminary draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Upper Birch Creek, Alaska possessed values which qualify it for inclusion in the National Wild and Scenic Rivers System. The upper Birch Creek and its immediate...

  7. The growth process of natural poplar-birch forests

    Institute of Scientific and Technical Information of China (English)

    LAN Shibo; LUO Xu; LUO Yuliang

    2006-01-01

    With a combination of permanent and temporary sample plots,we investigated the growth conditions of natural poplar-birch forests.The forests were divided into four site classes,using statistical and analytical techniques in a quantitative model,in descending order where site class I was the best.On this basis,the growth of natural poplar-birch forests in the different site classes was studied.The growth processes of height and diameter at breast height were divided into three stages:a fast growing period,a stable growing period and a slow growing period.Results of this study provide a theoretical basis for the directive cultivation of natural poplar-birch forests.

  8. Rhizofiltration of a Heavy metal (lead) containing wastewater using the wetland plant carex pendula

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Brijesh K. [Environmental Hydrogeology Group, Department of Earth Sciences, Faculty of Geosciences, University of Utrecht, Utrecht (Netherlands); Indian Institute of Technology Delhi, Department of Civil Engineering, New Delhi (India); Siebel, Maarten A.; Bruggen, Johan J.A. van [Department of Environmental Resources, UNESCO-IHE Institute for Water Education, Delft (Netherlands)

    2011-05-15

    Rhizofiltration is a subset technique of phytoremediation which refers to the approach of using plant biomass for removing contaminants, primarily toxic metals, from polluted water. The effective implementation of this in situ remediation technology requires experimental as well as conceptual insight of plant-water interactions that control the extraction of targeted metal from polluted water resources. Therefore, pot and simulation experiments are used in this study to investigate the rhizofiltration of a lead containing wastewater using plants of Carex pendula, a common wetland plant found in Europe. The metal contaminant extraction along with plant growth and water uptake rates from a wastewater having varying Pb concentration is studied experimentally for 2 wk. The temporal distribution of the metal concentration in the wastewater and the accumulated metal in different compartments of C. pendula at the end are analyzed using atomic absorption spectrometry. Parameters of the metal uptake kinetics are deduced experimentally for predicting the metal removal by root biomass. Further, mass balance equations coupled with the characterized metal uptake kinetics are used for simulating the metal partitioning from the wastewater to its accumulation in the plant biomass. The simulated metal content in wastewater and plant biomass is compared with the observed data showing a good agreement with the later. Results show that C. pendula accumulates considerable amounts of lead, particularly in root biomass, and can be considered for the cleanup of lead contaminated wastewaters in combination with proper biomass disposal alternatives. Also, the findings can be used for performing further non-hydroponics experiment to mimic the real wetland conditions more closely. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Molecular responses of plants to solar UV-B and UV-A radiation

    OpenAIRE

    Morales Suárez, Luis Orlando

    2014-01-01

    Plant responses to solar ultraviolet radiation (UV, 280-400 nm) were assessed at different molecular levels using Betula pendula Roth (silver birch) and Arabidopsis thaliana (Arabidopsis) as model species in outdoor experiments to assess the possibly interacting roles of the UV-B and UV-A wavebands in acclimation to sunlight. Solar UV-B (280-315 nm) and UV-A (315-400 nm) irradiance was attenuated with plastic films. Both solar UV-B and UV-A promoted the acclimation of silver birch and Arabido...

  10. A New Monoterpene Glucoside from the Leaves of Betula platyphylla Suk.

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new monoterpene glucoside, (2E,6Z)-2,6-dimethyl-8-b-D-glucosyloxy-2,6-octadien- oic acid, was isolated from the leaves of Betula platyphylla Suk. The structure was established by spectroscopic data.

  11. Nonlinear dynamics and synchronisation of pendula attached to a rotating hub

    Science.gov (United States)

    Warminski, J.; Szmit, Z.; Latalski, J.

    2014-04-01

    A model of a nonlinear system composed of a hub with attached two pendula rotating in a horizontal plane is studied in the paper. Each single pendulum, treated as a stiff and massless rod with a lumped mass, is connected to the hub by a flapping hinge. Nonlinear stiffness and viscous damping of the hinge is taken into consideration. The system is excited by an external torque generated by a DC motor which is considered as an ideal system with torque given by a harmonic function. For small oscillations the problem is linearised and then solved analytically. An influence of the structural parameters like mass of the hub and pendula length on natural end excited vibrations is presented. Large oscillations are studied by a continuation technique, directly from the original Ordinary Differential Equations of motion (ODE). The complete synchronisation, phase synchronisation, bifurcations and transition through resonances are analysed considering the influence of the mass of the hub. The existence of chaotic oscillations of the system and paths leading to chaos are demonstrated as well.

  12. Dehydrins in cold-acclimated apices of birch (Betula pubescens Ehr.) : production, localization and potential role in rescuing enzyme function during dehydration

    NARCIS (Netherlands)

    Rinne, P.L.H.; Kaikuranta, P.L.M.; Plas, van der L.H.W.; Schoot, van der C.

    1999-01-01

    Dehydrins accumulate in various plant tissues during dehydration. Their physiological role is not well understood, but it is commonly assumed that they assist cells in tolerating dehydration. Since in perennials the ability of the shoot apex to withstand dehydration is pivotal for survival through w

  13. Evaluation of sewage sludge impact on pine and birch development

    OpenAIRE

    Vaitkutė, Dovilė

    2009-01-01

    Sewage sludge could be used in forestry as enrichment of soil properties. It is also expected that sewage sludge which is rich in phosphorus, nitrogen and organic material can enhance the growth of tree seedlings in poor soils. Our study was performed in Taruskos experimental forest site in Panevezys region. The experimental site amended with industrial sewage sludge ten years ago was afforestated with birch and pine seedlings. The aim of our thesis is to evaluate the influence of sewage ...

  14. CO2 elevation improves photosynthetic performance in progressive warming environment in white birch seedlings [v1; ref status: indexed, http://f1000r.es/up

    Directory of Open Access Journals (Sweden)

    Shouren Zhang

    2013-01-01

    Full Text Available White birch (Betula paperifera Mash seedlings were exposed to progressively warming in greenhouses under ambient and elevated CO2 concentrations for 5 months to explore boreal tree species’ potential capacity to acclimate to global climate warming and CO2 elevation. In situ foliar gas exchange, in vivo carboxylation characteristics and chlorophyll fluorescence were measured at temperatures of 26oC and 37oC. Elevated CO2 significantly increased net photosynthetic rate (Pn at both measurement temperatures, and Pn at 37oC was higher than that at 26oC under elevated CO2. Stomatal conductance (gs was lower at 37oC than at 26oC, while transpiration rate (E was higher at 37oC than that at 26oC. Elevated CO2 significantly increased instantaneous water-use efficiency (WUE at both 26oC and 37oC, but WUE was markedly enhanced at 37oC under elevated CO2. The effect of temperature on maximal carboxylation rate (Vcmax, PAR-saturated electron transport rate (Jmax and triose phosphate utilization (TPU varied with CO2, and the Vcmax and Jmax were significantly higher at 37oC than at 26oC under elevated CO2. However, there were no significant interactive effects of CO2 and temperature on TPU. The actual photochemical efficiency of PSII (DF/ Fm’, total photosynthetic linear electron transport rate through PSII (JT and the partitioning of JT to carboxylation (Jc were higher at 37oC than at 26oC under elevated CO2. Elevated CO2 significantly suppressed the partitioning of JT to oxygenation (Jo/JT. The data suggest that the CO2 elevation and progressive warming greatly enhanced photosynthesis in white birch seedlings in an interactive fashion.

  15. Phenology and abundance in relation to climatic variation in a sub-arctic insect herbivore-mountain birch system.

    Science.gov (United States)

    Mjaaseth, Ragnhild R; Hagen, Snorre B; Yoccoz, Nigel G; Ims, Rolf A

    2005-08-01

    The two forest-defoliating geometrid moth species Operophtera brumata and Epirrita autumnata are known to exhibit different altitudinal distribution patterns in northern birch forests. One possible explanation for this is that altitudinal climatic variation differentially affects the performance of two species through mismatching larval and host plant phenology. We explored this hypothesis by investigating the relationship between larval phenology and leaf phenology of Betula pubescens, which is the main host plant of both moth species, along ten replicate altitudinal transects during two springs with contrasting climate in northern Norway. There was a distinct monotonous cline in host plant phenology with increasing altitude in both years of the study, but the development of the leaves were generally 14 days later in the first of the 2 years due to cold spring weather. We found that larval development of both species closely tracked host plant leaf phenology independent of altitude and year. However, at the time of sampling, E. autumnata was approximately one instar ahead of O. brumata at all altitudes, probably reflecting that E. autumnata has faster early instar growth than O. brumata. The abundance of O. brumata was lowest at the altitudinal forest-line, while E. autumnata was lowest near sea level. Our results do not indicate that the altitudinal distribution patterns of the two moth species is due to any phenological mismatch between larval and host plant phenology. We suggest rather that natural enemies at low altitudes limit larval survival and thus abundance of E. autumnata, while an early onset of winter at the forest limit reduces survival of late eclosing adults of O. brumata.

  16. ANALYSIS OF BIOLOGICAL GEOCHEMISTRY OF CHEMICAL ELEMENTS IN Betula ermanii FOREST IN CHANGBAI MOUNTAINS, CHINA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on catalogue of biology and geochemistry of chemical elements, content characteristics and variation law of the large nutrient elements, the needful trace elements, the uncertain needful elements, the non-needful elements and the toxic elements in Betula ermanii trees are analyzed. The result shows that the content of the large nutrient elements in Betula ermanii trees is higher than that of other kinds of element; the contents of all kinds of elements in foliage with vigorous metabolism are higher than those in other parts; the content variations of the large nutrient elements and the needful trace elements with similar chemical property, geochemical property and biological function in different parts of Betula ermanii trees show the similar laws; but the other three kinds of elements variations are without laws. It is indicated that the variation of the needful elements in the plant follows a certain law, they are in relative equilibrium under undisturbed condition.

  17. Description of the immature stages of Kuwanina betula Wu & Liu, with a discussion of its placement in the Acanthococcidae family group (Hemiptera: Coccoidea).

    Science.gov (United States)

    Wu, San-An; Nan, Nan

    2015-03-09

    The immature stages of Kuwanina betula Wu & Liu are described and illustrated. Based on morphological and molecular data (18S and 28S rDNA), it is argued that K. betula is closer to Pseudochermes Nitsche than to Kuwanina Cockerell in Fernald and so this species is transferred to Pseudochermes as P. betula (Wu & Liu) comb. nov..

  18. A new genus and species of gall midge (Diptera, Cecidomyiidae associated with Parkia pendula (Fabaceae, Mimosoideae Um novo gênero e espécie de mosquito galhador (Diptera: Cecidomyiidae associado com Parkia pendula (Fabaceae, Mimosoideae

    Directory of Open Access Journals (Sweden)

    Valéria Cid Maia

    2006-03-01

    Full Text Available Parkiamyia paraensis, a new genus and species of Cecidomyiidae that induces galls on Parkia pendula is described (larva, pupa, male,female and gall based on material from Pará (Brazil.Parkiamyia paraensis, um novo gênero e espécie de Cecidomyiidae é descrita (larva, pupa, macho e fêmea com base em material do Pará (Brasil.

  19. Dynamics of Betula ermanni population in subalpine vegetation in Changbai Mountain, Northeast China

    Institute of Scientific and Technical Information of China (English)

    Zou Chunjing; Han Shijie; Wang Xiaochun

    1999-01-01

    Betula ermanni population was divided into three groups: the upper population (2 000~2 200 m), the middle population (1 700~2000 m), and the down population (1 400~1 700 m) in Changbai Mountain. The dynamics of Betula ermanni populations in subalpine vegetation are studied and the population life table,fecundity schedule, survival curves, age structure, and fecundity curves were established. The results showed that the middle population is obviously the transition from the upper population to the down population.

  20. Magnetic Parkia pendula seed gum as matrix for Concanavalin A lectin immobilization and its application in affinity purification

    Directory of Open Access Journals (Sweden)

    MOACYR J.B.M. RÊGO

    2014-09-01

    Full Text Available The present work aimed to magnetize Parkia pendula seeds gum and use it as a matrix for Concanavalin A covalent immobilization. This composite was applied in affinity purification of glycoconjugates. Parkia pendula seeds were hydrated and the gum provenient from the supernatant was precipitated and washed with ethanol and dried. The gum was magnetized in co-precipitation using solutions of Fe+2 and Fe+3. Matrix activation was accomplished with NaIO4. Magnetized Parkia pendula seeds gum with covalently immobilized Concanavalin A was used as an affinity matrix for the recognition of bovine serum fetuin glycoprotein. Fetuin elution was carried out with a solution of glucose (300mM and evaluated through SDS-PAGE. The efficiency of lectin immobilization and fetuin purification were 63% and 14%, respectively. These results indicate that the composite produced is a promising magnetic polysaccharide matrix for lectins immobilization. Thus, such system can be applied for affinity purification allowing an easy recovery by magnetic field.

  1. Magnetic Parkia pendula seed gum as matrix for Concanavalin A lectin immobilization and its application in affinity purification.

    Science.gov (United States)

    Rêgo, Moacyr J B M; Almeida, Sinara M; Bezerra, Sérgio A; Carvalho Júnior, Luiz B; Beltrão, Eduardo I C

    2014-09-01

    The present work aimed to magnetize Parkia pendula seeds gum and use it as a matrix for Concanavalin A covalent immobilization. This composite was applied in affinity purification of glycoconjugates. Parkia pendula seeds were hydrated and the gum provenient from the supernatant was precipitated and washed with ethanol and dried. The gum was magnetized in co-precipitation using solutions of Fe+2 and Fe+3. Matrix activation was accomplished with NaIO4. Magnetized Parkia pendula seeds gum with covalently immobilized Concanavalin A was used as an affinity matrix for the recognition of bovine serum fetuin glycoprotein. Fetuin elution was carried out with a solution of glucose (300mM) and evaluated through SDS-PAGE. The efficiency of lectin immobilization and fetuin purification were 63% and 14%, respectively. These results indicate that the composite produced is a promising magnetic polysaccharide matrix for lectins immobilization. Thus, such system can be applied for affinity purification allowing an easy recovery by magnetic field.

  2. Specific probiotics alleviate allergic rhinitis during the birch pollen season

    Institute of Scientific and Technical Information of China (English)

    Arthur C Ouwehand; Merja Nermes; Maria Carmen Collado; Nina Rautonen; Seppo Salminen; Erika Isolauri

    2009-01-01

    AIM: To investigate whether birch pollen allergy symptoms are linked with gut microbiota changes and whether probiotics have an effect on these. METHODS: Forty seven children with confirmed birch pollen allergy were randomized to receive either a probiotic combination of Lactobacillus acidophilus ( L. acidophi lus) NCFMTM (ATCC 700396) and Bifidobacterium lactis ( B. lactis) Bl-04 (ATCC SD5219) or placebo in a double-blind manner for 4 mo, starting prior to onset of the birch pollen season. Symptoms were recorded in a diary. Blood samples were taken for analysis of cytokines and eosinophils. Fecal samples were analysed for microbiota components, calprotectin and IgA. Nasal swabs were taken for analysis of eosinophils.RESULTS: The pollen season induced a reduction in Bifidobacterium, Clostridium and Bacteroides which could not be prevented by the probiotic intervention. During the intervention, significantly higher numbers 106 bacteria/g feces ( P < 0.0001) were observed in the probiotic group compared to the placebo group. During May, there was a tendency for fewer subjects,(76.2% vs 95.2%, P = 0.078) to report runny nose,while during June, fewer subjects, 11.1% vs 33.3%,reported nasal blocking in the probiotics group ( P = 0.101). Concomitantly, fewer subjects in the probiotic group had infiltration of eosinophils in the nasal mucosa compared to the placebo group, 57.1%vs 95% ( P = 0.013). Eye symptoms tended to be slightly more frequent in the probiotic group, 12.5 d [interquartile range (IQR) 6-18] vs 7.5 d (IQR 0-11.5)( P = 0.066) during May. Fecal IgA was increased in the placebo group during the pollen season; this increase was prevented by the probiotics ( P = 0.028).CONCLUSION: Birch pollen allergy was shown to be associated with changes in fecal microbiota composition. The specific combination of probiotics used was shown to prevent the pollen-induced infiltration of eosinophils into the nasal mucosa, and indicated a trend for reduced nasal symptoms.

  3. 78 FR 15681 - Beaverhead-Deerlodge National Forest, Dillon Ranger District; Montana; Birch, Willow, Lost Project

    Science.gov (United States)

    2013-03-12

    ... Forest Service Beaverhead-Deerlodge National Forest, Dillon Ranger District; Montana; Birch, Willow, Lost... statement. SUMMARY: The Birch, Willow, Lost Project proposes to treat vegetation communities in the four sub.... FR 7476 (Lower Willow Creek) would have 1.7 miles Spot Reconstructed. FR 8200 (Willow Creek)...

  4. Impact of urbanization of the proteome of birch pollen and its chemotactic activity on human granulocytes

    NARCIS (Netherlands)

    Bryce, M.; Drews, O.; Schenk, M.F.; Menzel, A.; Estrella, N.; Weichenmeier, I.; Smulders, M.J.M.; Buters, J.; Ring, J.; Gorg, A.; Behrendt, H.; Traidl-Hoffmann, C.

    2010-01-01

    Background: Epidemiologic studies reveal a dramatic increase in allergies in the last decades. Air pollution is considered to be one of the factors responsible for this augmentation. The aim of this study was to analyze the impact of urbanization on birch pollen. The birch pollen proteome was invest

  5. PLATYPHYLLIN A, A NOVEL COUMARONE FROM THE LEAVES OF BETULA PLATYPHYLLA SUK.

    Institute of Scientific and Technical Information of China (English)

    SU-JUAN WANG; YUE-HU PEI; HUI-MING HUA

    2001-01-01

    A novel coumarone, platyphyllin A (1), was isolated from the leaves of Betula platyphylla Suk..The structure elucidation was accomplished by the analysis of spectroscopic data. Compound 1 was identified as a new coumarone skeleton, which was first isolated from plants.

  6. Comparative Carbon and Water Relations of Betula nana and Poa pratensis in West Greenland

    Science.gov (United States)

    Cahoon, S. M. P.; Sullivan, P. F.; Welker, J. M.; Post, E.

    2014-12-01

    The expansion of woody shrubs throughout much of the Arctic in recent decades is a common observation in response to climate change. However, we lack a complete understanding of how woody shrubs differ physiologically from neighboring species and how these differences may confer competitive advantages to woody shrubs as the climate continues to change. At a site in West Greenland, we combined detailed leaf physiological measurements with stable isotope analysis of plant leaf material, xylem water and soil water to elucidate the processes governing seasonal carbon (C) gain in the two dominant plant species at our study site: Betula nana and Poa pratensis. We hypothesized that cooler, drier soils beneath the Betula canopy would result in greater drought sensitivity during times of high atmospheric demand (i.e. greater water vapor pressure deficit; VPD), which would manifest in reduced leaf carbon isotope discrimination (Δ13C), reduced stomatal conductance (gs) and a negative relationship between leaf Δ13C and Δ18O in accordance with the dual-isotope conceptual model. Data collected over two consecutive growing seasons, however, revealed greater drought sensitivity in Poa, which displayed a dramatic reduction in Amax and gs during periods of high VPD, along with reduced leaf Δ13C. Additionally, leaf Δ13C and Δ18O were negatively correlated in Poa, suggesting strong stomatal influence on Δ13C. Conversely, we found no relationship between leaf Δ13C and Δ18O in Betula, indicating that seasonal variation in Δ13C may have been driven primarily by changes in photosynthesis. Our results suggest that, although Poa maintains greater average leaf-level photosynthesis, this species is more susceptible to drought than Betula. Meanwhile, it may be that Betula employs a strategy to avoid drought stress and maintain steady, yet conservative, C gain. This strategy may enable growth to continue during warm and dry conditions, conferring a competitive advantage for Betula in

  7. [A relationship between birch pollen counts and meteorological factors in Sapporo].

    Science.gov (United States)

    Shirasaki, Hideaki; Yamamoto, Tetsuo; Saikawa, Etsuko; Seki, Nobuhiko; Asakura, Kohji; Kataura, Akikatsu; Himi, Tetsuo

    2014-05-01

    Occurrence of airborne pollen in Sapporo has been studied for 19 years during the period between 1995 and 2013. There are wide year-to-year variations in the quantities of birch pollens. A simple linear regression with the least squares method was used for studying correlations between the annual quantities of birch pollens and the meteorological factors. A significant positive correlation was found between the hours of sunlight in June of the preceding year and the annual birch pollen concentrations with the correlation coefficient, R = 0.667. Also, we found the significant positive correlation between the hours of sunlight in March and the annual birch pollen concentrations with the correlation coefficient, R = 0.684. These results suggest that the atmospheric birch pollen counts can be predicted from meteorological factors.

  8. Shrub encroachment in Arctic tundra: Betula nana effects on above- and below-ground litter decomposition.

    Science.gov (United States)

    McLaren, Jennie R; Buckeridge, Kate M; van de Weg, Martine J; Shaver, Gaius R; Schimel, Joshua P; Gough, Laura

    2017-03-06

    Rapid arctic vegetation change as a result of global warming includes an increase in the cover and biomass of deciduous shrubs. Increases in shrub abundance will result in a proportional increase of shrub litter in the litter community, potentially affecting carbon turnover rates in arctic ecosystems. We investigated the effects of leaf and root litter of a deciduous shrub, Betula nana, on decomposition, by examining species-specific decomposition patterns, as well as effects of Betula litter on the decomposition of other species. We conducted a two-year decomposition experiment in moist acidic tundra in northern Alaska, where we decomposed three tundra species (Vaccinium vitis-idaea, Rhododendron palustre, and Eriophorum vaginatum) alone and in combination with Betula litter. Decomposition patterns for leaf and root litter were determined using three different measures of decomposition (mass loss, respiration, extracellular enzyme activity). We report faster decomposition of Betula leaf litter compared to other species, with support for species differences coming from all three measures of decomposition. Mixing effects were less consistent among the measures, with negative mixing effects shown only for mass loss. In contrast, there were few species differences or mixing effects for root decomposition. Overall, we attribute longer-term litter mass loss patterns in to patterns created by early decomposition processes in the first winter. We note numerous differences for species patterns between leaf and root decomposition, indicating that conclusions from leaf litter experiments should not be extrapolated to below-ground decomposition. The high decomposition rates of Betula leaf litter aboveground, and relatively similar decomposition rates of multiple species below, suggest a potential for increases in turnover in the fast-decomposing carbon pool of leaves and fine roots as the dominance of deciduous shrubs in the Arctic increases, but this outcome may be tempered

  9. A method to derive vegetation distribution maps for pollen dispersion models using birch as an example.

    Science.gov (United States)

    Pauling, A; Rotach, M W; Gehrig, R; Clot, B

    2012-09-01

    Detailed knowledge of the spatial distribution of sources is a crucial prerequisite for the application of pollen dispersion models such as, for example, COSMO-ART (COnsortium for Small-scale MOdeling-Aerosols and Reactive Trace gases). However, this input is not available for the allergy-relevant species such as hazel, alder, birch, grass or ragweed. Hence, plant distribution datasets need to be derived from suitable sources. We present an approach to produce such a dataset from existing sources using birch as an example. The basic idea is to construct a birch dataset using a region with good data coverage for calibration and then to extrapolate this relationship to a larger area by using land use classes. We use the Swiss forest inventory (1 km resolution) in combination with a 74-category land use dataset that covers the non-forested areas of Switzerland as well (resolution 100 m). Then we assign birch density categories of 0%, 0.1%, 0.5% and 2.5% to each of the 74 land use categories. The combination of this derived dataset with the birch distribution from the forest inventory yields a fairly accurate birch distribution encompassing entire Switzerland. The land use categories of the Global Land Cover 2000 (GLC2000; Global Land Cover 2000 database, 2003, European Commission, Joint Research Centre; resolution 1 km) are then calibrated with the Swiss dataset in order to derive a Europe-wide birch distribution dataset and aggregated onto the 7 km COSMO-ART grid. This procedure thus assumes that a certain GLC2000 land use category has the same birch density wherever it may occur in Europe. In order to reduce the strict application of this crucial assumption, the birch density distribution as obtained from the previous steps is weighted using the mean Seasonal Pollen Index (SPI; yearly sums of daily pollen concentrations). For future improvement, region-specific birch densities for the GLC2000 categories could be integrated into the mapping procedure.

  10. Geochemistry of the Birch Creek Drainage Basin, Idaho

    Science.gov (United States)

    Swanson, Shawn A.; Rosentreter, Jeffrey J.; Bartholomay, Roy C.; Knobel, LeRoy L.

    2003-01-01

    The U.S. Survey and Idaho State University, in cooperation with the U.S. Department of Energy, are conducting studies to describe the chemical character of ground water that moves as underflow from drainage basins into the eastern Snake River Plain aquifer (ESRPA) system at and near the Idaho National Engineering and Environmental Laboratory (INEEL) and the effects of these recharge waters on the geochemistry of the ESRPA system. Each of these recharge waters has a hydrochemical character related to geochemical processes, especially water-rock interactions, that occur during migration to the ESRPA. Results of these studies will benefit ongoing and planned geochemical modeling of the ESRPA at the INEEL by providing model input on the hydrochemical character of water from each drainage basin. During 2000, water samples were collected from five wells and one surface-water site in the Birch Creek drainage basin and analyzed for selected inorganic constituents, nutrients, dissolved organic carbon, tritium, measurements of gross alpha and beta radioactivity, and stable isotopes. Four duplicate samples also were collected for quality assurance. Results, which include analyses of samples previously collected from four other sites, in the basin, show that most water from the Birch Creek drainage basin has a calcium-magnesium bicarbonate character. The Birch Creek Valley can be divided roughly into three hydrologic areas. In the northern part, ground water is forced to the surface by a basalt barrier and the sampling sites were either surface water or shallow wells. Water chemistry in this area was characterized by simple evaporation models, simple calcite-carbon dioxide models, or complex models involving carbonate and silicate minerals. The central part of the valley is filled by sedimentary material and the sampling sites were wells that are deeper than those in the northern part. Water chemistry in this area was characterized by simple calcite-dolomite-carbon dioxide

  11. ALKALINE PRETREATMENT OF SPRUCE AND BIRCH TO IMPROVE BIOETHANOL AND BIOGAS PRODUCTION

    Directory of Open Access Journals (Sweden)

    Azam Jeihanipour

    2010-05-01

    Full Text Available Alkaline pretreatment with NaOH under mild operating conditions was used to improve ethanol and biogas production from softwood spruce and hardwood birch. The pretreatments were carried out at different temperatures between minus 15 and 100ºC with 7.0% w/w NaOH solution for 2 h. The pretreated materials were then enzymatically hydrolyzed and subsequently fermented to ethanol or anaerobically digested to biogas. In general, the pretreatment was more successful for both ethanol and biogas production from the hardwood birch than the softwood spruce. The pretreatment resulted in significant reduction of hemicellulose and the crystallinity of cellulose, which might be responsible for improved enzymatic hydrolyses of birch from 6.9% to 82.3% and spruce from 14.1% to 35.7%. These results were obtained with pretreatment at 100°C for birch and 5°C for spruce. Subsequently, the best ethanol yield obtained was 0.08 g/g of the spruce while pretreated at 100°C, and 0.17 g/g of the birch treated at 100°C. On the other hand, digestion of untreated birch and spruce resulted in methane yields of 250 and 30 l/kg VS of the wood species, respectively. The pretreatment of the wood species at the best conditions for enzymatic hydrolysis resulted in 83% and 74% improvement in methane production from birch and spruce.

  12. The human eosinophil proteome. Changes induced by birch pollen allergy.

    Science.gov (United States)

    Woschnagg, Charlotte; Forsberg, Jens; Engström, Ake; Odreman, Federico; Venge, Per; Garcia, Rodolfo C

    2009-06-01

    Proteins from human eosinophils were separated bidimensionally and identified by mass spectrometry (336 spots/bands, 98 different proteins). Of these, 24.7% belonged to the cytoskeleton/migration group. Highly basic proteins (11.3%) were concentrated in the granule-containing cell fraction. We detected novel hyperacidic forms of cofilin-1, profilin-1 and adenylyl cyclase-associated protein, and hyperbasic forms of eosinophil-derived neurotoxin/eosinophil protein X and major basic protein homologue. We also found evidence of the triglycosylation of the heavy chain of eosinophil peroxidase. In addition, through comparative 2D image analysis, spot quantification and MS, it was found that hsc70, actin-capping protein and hyperacidic forms of eosinophil peroxidase heavy chain are overexpressed in cells from birch pollen allergic subjects, at the peak of a season. The link between these findings and an increased cellular antigen-presenting capacity and motility are discussed.

  13. Clerodane type diterpene as a novel antifungal agent from Polyalthia longifolia var. pendula.

    Science.gov (United States)

    Bhattacharya, Asish K; Chand, Hemender R; John, Jyothis; Deshpande, Mukund V

    2015-04-13

    Bioactivity-guided chemical examination of methanolic extract of leaves of Polyalthia longifolia var. pendula led to the isolation of the active constituent, a diterpene 1 which was identified as 16α-hydroxycleroda-3,13(14)Z-dien-15,16-olide on the basis of its spectral data. Among the tested strains, diterpene 1 was found to exhibit antifungal activities having MIC90 values of 50.3, 100.6 and 201.2 μM against Candida albicans NCIM3557, Cryptococcus neoformans NCIM3542 (human pathogens) and Neurospora crassa NCIM870 (saprophyte), respectively. Initial, structure-activity-relationship (SAR) data generated by synthesizing some derivatives revealed that the double bond between C3-C4 and the free hydroxyl group at C16 are crucial for the antifungal activity of the diterpene 1. The mode of action of 1 in C. albicans is due to compromised cell membrane permeability and also probably due to disruption of cell wall structures. The red blood cell haemolysis of all the compounds (1-4) did not show any significant haemolysis and was found to be less than 15% for all the compounds when tested at highest concentration, i.e. 1200 μM. Interestingly, all the tested compounds inhibited Y-H transition in dimorphic C. albicans NCIM3557 at much lower concentration than their MIC90 values. Determination of ROS generation by diterpene 1 using DCFH-DA and DHR123 (dihydrorhodamine) staining of C. albicans NCIM3557 indicated production of intracellular ROS as a mechanism of antifungal activity.

  14. The effect of meteorological factors on airborne Betula pollen concentrations in Lublin (Poland).

    Science.gov (United States)

    Piotrowska, Krystyna; Kubik-Komar, Agnieszka

    2012-12-01

    The present study investigated the pattern of the birch atmospheric pollen seasons in Lublin in the period 2001-2010. Pollen monitoring was conducted using a Lanzoni VPPS 2000 sampler. The atmospheric pollen seasons were determined with the 98% method. Regression analysis was used to determine correlations between meteorological conditions and the pattern of the birch pollen season. On average, the birch pollen season started on 12 April, ended on 13 May, and lasted 32 days. The peak value and the Seasonal Pollen Index showed the greatest variation in particular years. All the seasons were right-skewed. During the study years, a trend was found towards earlier occurrence of the seasonal peak. Regression equations were developed for the following parameters of the atmospheric pollen season: start, duration, peak value and average pollen concentration during the season. The obtained model fit was at a level of 64-81%. Statistical analysis shows that minimum temperature of February and March and total rainfall in June in the year preceding pollen release have the greatest effect on the birch atmospheric pollen season in Lublin. Low temperatures in February promote the occurrence of high pollen concentrations.

  15. Characterization of Hardwood Soda-AQ Lignins Precipitated from Black Liquor through Selective Acidification

    OpenAIRE

    Kumar, Hemanathan; Alén, Raimo; Sahoo, Gokarneswar

    2016-01-01

    In the development of integrated biorefinery process alternatives to produce value-added by-products, various black liquors from sulfur-free pulping processes offer potential feedstocks for recovering their main chemical constituents, lignin and aliphatic carboxylic acids. In this study, lignin fractions were obtained from silver birch (Betula pendula) soda-anthraquinone black liquor by carbonation (pH to about 8.5) or by acidification (pH to about 2) with H2SO4 after carbonation or directly....

  16. Daily home measurements of exhaled nitric oxide in asthmatic children during natural birch pollen exposure

    DEFF Research Database (Denmark)

    Vahlkvist, Signe; Sinding, Marianne; Skamstrup, Kirsten;

    2006-01-01

    the feasibility, repeatability, accuracy, sensitivity, and biologic plausibility of new handheld equipment for FENO measurements. We studied day-to-day home measurements of FENO during the birch pollen season in children with allergy to birch pollen and a history of mild asthma and rhinoconjunctivitis during......BACKGROUND: Fractional exhaled nitric oxide (FENO) is a sensitive marker of eosinophilic airway inflammation in asthma. Available methods have restricted measurements to the clinic, giving only a snapshot of the disease, which by nature is highly variable. OBJECTIVES: We sought to investigate...... this season, as well as in nonatopic children. METHODS: Eleven children with mild asthma and allergy to birch pollen, performed daily home measurements of FENO for 6 weeks before and during the birch pollen season by using a handheld FENO monitor (NIOX MINO). Additionally, FENO (chemiluminescence equipment...

  17. Bayesian analysis of climate change effects on observed and projected airborne levels of birch pollen

    Science.gov (United States)

    Zhang, Yong; Isukapalli, Sastry S.; Bielory, Leonard; Georgopoulos, Panos G.

    2013-04-01

    A Bayesian framework is presented for modeling effects of climate change on pollen indices such as annual birch pollen count, maximum daily birch pollen count, start date of birch pollen season and the date of maximum daily birch pollen count. Annual mean CO2 concentration, mean spring temperature and the corresponding pollen index of prior year were found to be statistically significant accounting for effects of climate change on four pollen indices. Results suggest that annual productions and peak values from 2020 to 2100 under different scenarios will be 1.3-8.0 and 1.1-7.3 times higher respectively than the mean values for 2000, and start and peak dates will occur around two to four weeks earlier. These results have been partly confirmed by the available historical data. As a demonstration, the emission profiles in future years were generated by incorporating the predicted pollen indices into an existing emission model.

  18. THE INFLUENCE OF CATIONIZED BIRCH XYLAN ON WET AND DRY STRENGTH OF FINE PAPER

    Directory of Open Access Journals (Sweden)

    Janne Kataja-aho,

    2012-02-01

    Full Text Available Cationized birch xylan was prepared and its use as a papermaking chemical was evaluated. The focus was on studying the effects of cationized birch xylan on the wet and dry strength of fine paper. The results of the laboratory experiments show that the addition of 3 percent of cationized birch xylan to birch kraft pulp improved the initial wet strength of the web by 30 percent compared to base stock at a solids content of 55%. Furthermore, the tensile stiffness of the wet web increased by approximately a third and the dry tensile strength improved by 26%, while the dry elastic modulus was not changed. The improvements in the strength properties were clear when compared to the base stock, but not as high as achieved with conventionally used cationized starch. The difference between the xylan and starch is most likely due to the shorter polymer chain length of the cationized xylan.

  19. Local variation in mountain birch spring phenology along an altitudinal gradient in northern coastal Fennoscandia

    OpenAIRE

    Sjöskog, Maja Sofia

    2011-01-01

    Currently there is a lack of spring phenology studies covering small-scale altitudinal gradients of mountain birch in coastal northern Fennoscandia, a region characterized by exceptionally high precipitation of snow, which gives reason to investigate the influence of snow cover on birch budburst in this area. Furthermore, ground phenology studies are today increasingly replaced by satellite data studies, but only too rarely is the latter approach properly validated. In order to provide a bett...

  20. Ecosystem nitrogen fixation throughout the snow-free period in subarctic tundra: effects of willow and birch litter addition and warming.

    Science.gov (United States)

    Rousk, Kathrin; Michelsen, Anders

    2017-04-01

    Nitrogen (N) fixation in moss-associated cyanobacteria is one of the main sources of available N for N-limited ecosystems such as subarctic tundra. Yet, N2 fixation in mosses is strongly influenced by soil moisture and temperature. Thus, temporal scaling up of low-frequency in situ measurements to several weeks, months or even the entire growing season without taking into account changes in abiotic conditions cannot capture the variation in moss-associated N2 fixation. We therefore aimed to estimate moss-associated N2 fixation throughout the snow-free period in subarctic tundra in field experiments simulating climate change: willow (Salix myrsinifolia) and birch (Betula pubescens spp. tortuosa) litter addition, and warming. To achieve this, we established relationships between measured in situ N2 fixation rates and soil moisture and soil temperature and used high-resolution measurements of soil moisture and soil temperature (hourly from May to October) to model N2 fixation. The modelled N2 fixation rates were highest in the warmed (2.8 ± 0.3 kg N ha(-1) ) and birch litter addition plots (2.8 ± 0.2 kg N ha(-1) ), and lowest in the plots receiving willow litter (1.6 ± 0.2 kg N ha(-1) ). The control plots had intermediate rates (2.2 ± 0.2 kg N ha(-1) ). Further, N2 fixation was highest during the summer in the warmed plots, but was lowest in the litter addition plots during the same period. The temperature and moisture dependence of N2 fixation was different between the climate change treatments, indicating a shift in the N2 fixer community. Our findings, using a combined empirical and modelling approach, suggest that a longer snow-free period and increased temperatures in a future climate will likely lead to higher N2 fixation rates in mosses. Yet, the consequences of increased litter fall on moss-associated N2 fixation due to shrub expansion in the Arctic will depend on the shrub species' litter traits.

  1. METAL ION SORPTION TO BIRCH AND SPRUCE WOOD

    Directory of Open Access Journals (Sweden)

    Pingping Su,

    2012-02-01

    Full Text Available Sorption of metal ions from aqueous solutions to birch wood and spruce heartwood and sapwood has been studied. Functional groups in wood were determined by acid-base titrations. The sorption of metal ions to wood of the different tree species was investigated by a column chromatographic technique. The mechanism of sorption is mainly ion exchange by complexation of metal ions to the functional groups, e.g. carboxyl groups and phenolic hydroxyl groups, in the wood phase. By combination of the sorption experiments with four different metal ion mixtures, the following affinity order was established for spruce sapwood particles: Fe3+>>Pb2+>>Cu2+>>Fe2+>Cd2+>Zn2+>Ni2+>Mn2+≥Ca2+≥Sr2+≥Ba2+>>Mg2+>>K+>Na+≈Li+. For all three types of stemwood studied, the affinity orders were almost the same. The ion exchange properties of wood were comparable to those of a weakly acid cation exchanger. The affinity order obtained for the synthetic resin was quite similar to the order given above for wood. The metal sorption properties of wood materials imply that they could be a potential material for removal of metal ions from aqueous solutions.

  2. BIRCH XYLAN GRAFTED WITH PLA BRANCHES OF PREDICTABLE LENGTH

    Directory of Open Access Journals (Sweden)

    Johanna Persson,

    2012-06-01

    Full Text Available Birch xylan (4-O-methylglucuronoxylan isolated from a kraft cooking liquor was delignified and grafted with polylactide of predictable branch length. This graft copolymerization resulted in very high total yields, greater than 90%, and with less than 10% polylactide homopolymer byproducts. Mild reaction conditions (40°C, 5 to 120 minutes were used, which was believed to limit transesterification reactions and thus make it possible to reach good predictability of the polylactide branch length. The thermal properties of the polylactide-grafted xylan depended on the branch length. Short branches resulted in fully amorphous materials with a glass transition temperature of about 48 to 55°C, whereas long polylactide branches resulted in semi-crystalline materials with melting points of about 130°C. Using mixtures of L-lactide and D/L-lactide in the monomer feed further altered the thermal properties. The degradation temperatures of the polylactide-grafted xylans were higher than that of the unmodified xylan, with degradation temperatures of about 300°C and 250°C, respectively. Tensile testing showed increased elongation at break with increasing branch length. The proposed method thus enables tailor-making of copolymers with specific thermal and mechanical properties.

  3. Hidrocondicionamento de Parkia pendula [Benth ex Walp]: sementes com dormência física de árvore da Amazônia Hydropriming of Parkia pendula [Penth. ex Walp.]: seeds with physical dormancy from Amazon tree

    Directory of Open Access Journals (Sweden)

    Gina Janet Vargas Pinedo

    2008-02-01

    Full Text Available O visgueiro é uma árvore neotropical de importâncias econômica e ecológica. Este estudo objetivou determinar o tempo de embebição e o teor de água de sementes de Parkia pendula necessários para ativar o metabolismo e aumentar o desempenho pelo condicionamento. Sementes armazenadas (2 anos e não armazenadas (7 dias foram comparadas. Após o desponte as sementes foram submersas em água a 15 ºC, por períodos de 4 a 28 h, para atingir o grau de embebição desejado (20, 40, 60, 80 e 90%. Em seguida, foram diretamente semeadas em areia lavada no viveiro (4 x 25 sementes/tratamento ou dessecadas durante sete dias (24±2 °C e 68±3% UR antes da semeadura. Sementes não armazenadas e sem condicionamento (controle apresentaram 59±8,9% de emergência, valor inferior ao daquelas armazenadas e sem condicionamento (76±11,3%. Períodos de submersão superiores a 13 h reduziram o desempenho da germinação em relação às sementes não condicionadas. Porém, após 4 h (26-31% de teor de água das sementes ambas as sementes não armazenadas e armazenadas aumentaram o desempenho, sendo, ainda, maior quando houve dessecamento após a submersão. Portanto, os efeitos positivos do condicionamento ocorreram na fase I da curva de embebição. O hidrocondicionamento de 4 h a 15 ºC mostrou ser uma opção econômica e de fácil aplicação em sementes de P. pendula: aumentou a velocidade do desenvolvimento das plântulas, a porcentagem de germinação das sementes não armazenadas em níveis similares aos das armazenadas e a sincronização da germinação em sementes armazenadas.Visgueiro is a neo-tropical tree species with economic and ecologic importance. This work aimed to determine the imbibition time and moisture content of P. pendula seeds necessary to activate metabolism and improve their performance by priming. Stored seeds (2 years and unstored seeds (7 days were compared. After clipping, the seeds were kept in water at 15 ºC for periods of

  4. The Sine-Gordon model and its applications from pendula and Josephson junctions to gravity and high-energy physics

    CERN Document Server

    Kevrekidis, Panayotis; Williams, Floyd

    2014-01-01

    The sine-Gordon model is a ubiquitous model of Mathematical Physics with a wide range of applications extending from coupled torsion pendula and Josephson junction arrays to gravitational and high-energy physics models. The purpose of this book is to present a summary of recent developments in this field, incorporating both introductory background material, but also with a strong view towards modern applications, recent experiments, developments regarding the existence, stability, dynamics and asymptotics of nonlinear waves that arise in the model. This book is of particular interest to a wide range of researchers in this field, but serves as an introductory text for young researchers and students  interested in the topic. The book consists of well-selected thematic chapters on diverse mathematical and physical aspects of the equation carefully chosen and assigned.

  5. Structural analysis of heat-treated birch (Betule papyrifera) surface during artificial weathering

    Energy Technology Data Exchange (ETDEWEB)

    Huang Xianai [Universite du Quebec a Chicoutimi, 555, boul. de l' Universite, Chicoutimi, Quebec, G7H 2B1 (Canada); Kocaefe, Duygu, E-mail: dkocaefe@uqac.ca [Universite du Quebec a Chicoutimi, 555, boul. de l' Universite, Chicoutimi, Quebec, G7H 2B1 (Canada); Kocaefe, Yasar [Universite du Quebec a Chicoutimi, 555, boul. de l' Universite, Chicoutimi, Quebec, G7H 2B1 (Canada); Boluk, Yaman [University of Alberta, 3-142 Markin/CNRL Natural Resources Engineering Facility, Edmonton, Alberta, T6G 2W2 (Canada); Krause, Cornelia [Universite du Quebec a Chicoutimi, 555, boul. de l' Universite, Chicoutimi, Quebec, G7H 2B1 (Canada)

    2013-01-01

    Highlights: Black-Right-Pointing-Pointer Investigate detailed structural changes of heat-treated wood due to weathering. Black-Right-Pointing-Pointer Identify connection between physical structural changes and chemical degradation. Black-Right-Pointing-Pointer Study effect of heat treatment conditions on weathering degradation process. - Abstract: Effect of artificial weathering on the surface structural changes of birch (Betule papyrifera) wood, heat-treated to different temperatures, was studied using the fluorescence microscopy and the scanning electron microscopy (SEM). Changes in the chemical structure of wood components were analyzed by FTIR in order to understand the mechanism of degradation taking place due to heat treatment and artificial weathering. The results are compared with those of the untreated (kiln-dried) birch. The SEM analysis results show that the effect of weathering on the cell wall of the untreated birch surface is more than that of heat-treated samples. The FTIR spectroscopy results indicate that lignin is the most sensitive component of heat-treated birch to the weathering degradation process. Elimination of the amorphous and highly crystallised cellulose is observed for both heat-treated and untreated wood during weathering. It is also observed that heat treatment increases the lignin and crystallised cellulose contents, which to some extent protects heat-treated birch against degradation due to weathering.

  6. Differential response of aspen and birch trees to heat stress under elevated carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Darbah, Joseph N.T., E-mail: darbah@ohio.ed [School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931 (United States); Department of Environmental and Plant Biology, Ohio University, 315 Porter Hall, Athens, OH 45701 (United States); Sharkey, Thomas D. [Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824 (United States); Calfapietra, Carlo [Institute of Agro-Environmental and Forest Biology (IBAF), National Research Council (CNR), Via Salaria km 29300, 00016 Monterotondo Scalo, Roma (Italy); Karnosky, David F. [School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931 (United States)

    2010-04-15

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO{sub 2} and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO{sub 2} protected photosynthesis of both species against moderate heat stress. Elevated CO{sub 2} increased carboxylation capacity, photosynthetic electron transport capacity, and triose phosphate use in both birch and aspen trees. High temperature (36-39 deg. C) decreased all of these parameters in birch regardless of CO{sub 2} treatment, but only photosynthetic electron transport and triose phosphate use at ambient CO{sub 2} were reduced in aspen. Among the two aspen clones tested, 271 showed higher thermotolerance than 42E possibly because of the higher isoprene-emission, especially under elevated CO{sub 2}. Our results indicate that isoprene-emitting trees may have a competitive advantage over non-isoprene emitting ones as temperatures rise, indicating that biological diversity may be affected in some ecosystems because of heat tolerance mechanisms. - We report that elevated CO{sub 2} confers increased thermotolerance on both aspen and birch trees while isoprene production in aspen confers further thermotolerance in aspen.

  7. Structural analysis of heat-treated birch (Betule papyrifera) surface during artificial weathering

    Science.gov (United States)

    Huang, Xianai; Kocaefe, Duygu; Kocaefe, Yasar; Boluk, Yaman; Krause, Cornélia

    2013-01-01

    Effect of artificial weathering on the surface structural changes of birch (Betule papyrifera) wood, heat-treated to different temperatures, was studied using the fluorescence microscopy and the scanning electron microscopy (SEM). Changes in the chemical structure of wood components were analyzed by FTIR in order to understand the mechanism of degradation taking place due to heat treatment and artificial weathering. The results are compared with those of the untreated (kiln-dried) birch. The SEM analysis results show that the effect of weathering on the cell wall of the untreated birch surface is more than that of heat-treated samples. The FTIR spectroscopy results indicate that lignin is the most sensitive component of heat-treated birch to the weathering degradation process. Elimination of the amorphous and highly crystallised cellulose is observed for both heat-treated and untreated wood during weathering. It is also observed that heat treatment increases the lignin and crystallised cellulose contents, which to some extent protects heat-treated birch against degradation due to weathering.

  8. 青海省湟水流域红桦林的分布规律%Distribution Law of Betula albo-sinensis Qinghai Huangshui River Valley

    Institute of Scientific and Technical Information of China (English)

    周生华

    2012-01-01

    通过二类资源调查数据总结了青海湟水流域的红桦林的分布及生境、组成与结构、林型、生长规律及更新与演替。调查结果表明:红桦林分布地区气候干湿季分明,分布区海拔2300—2900m;林分结构和组成不稳定且复杂;林型同龄单层纯林居多,主要有为苔草红桦林和灌木红桦林2种,相林不整齐,生长缓慢,树干分叉多枝,干形弯曲,尖削度较大,立木多呈团状分布。林分分层明显,可分为乔木层、下木层、草被层、苔藓层等四个层次;20龄后开始结实,40年后进入盛期,非常有利于天然更新。现有红桦林绝大部分是云杉林被破坏后而形成的次生林,红桦幼树随着年龄的增大,需光量也随之增加,常因不能忍受林内较弱的光照而逐渐衰弱和死亡。属云杉林演替过程中的一个过渡阶段。%Through Two types of resources survey data the paper summarize distribution and habitat, the composition and structure of forest types, growth regulation, and update and succession of Betula albo-sinensis Huangshui valley Qinghai. The survey results show that:distribution of regional climate wet and dry season clearly, the distribution of district elevation 2300-2900 ; stand structure and composition of the instability and complexity; forest types have monolayer pure forest, and shrub birch, forest irregular, slow growth, trunk forked branch, trunk-shaped bend, taper, stump mostly slug distribution. The obvious stand stratification, can be divid- ed into four levels of the tree layer,the understory layer,grass layer, moss layer; strong after 20 age ,40 years after the peak, is very conducive to natural regeneration. Existing birch, most of the spruce forest is destroyed after the formation of secondary forest, with age increases, the required amount of light also increases, often because they can not put up with weak light in the forest and gradually weakened and death

  9. Flavonoids in the leaves of polish species of the genus Betula L. III. The flavonoids of B. oycoviensis Bess. leaves

    Directory of Open Access Journals (Sweden)

    Lucyna Pawłowska

    2014-01-01

    Full Text Available B. oycoviensis Bess. leaves were found to contain compounds characteristic of B. "nova" i.e. myricitrin, isoquercitrin and probably also kaempferol 3-rhamno-7-glucoside, quercetin 3,7,4'-trimethyl ether, and quercetin 7,3',4'-trimethyl ether. They also contain compounds which occur in B. pendula Roth. (kaempferol 3-glucoside, isorhamnetin 3-glactoside, 6-methoxykaempferide, acacetin 7-glucoside, and probably scutellarein 7-glycoside. These biochemical traits bring out still better the hybrid origin of B. oycoviensis.

  10. DNA extraction of birch leaves by improved CTAB method and optimization of its ISSR system

    Institute of Scientific and Technical Information of China (English)

    PAN hua; YANG Chuan-ping; WEI Zhi-gang; JIANG Jing

    2006-01-01

    The basic method of DNA extraction (CTAB) was improved as the multi-times STE-CTAB extraction method and used to extract the DNA of birch leaved in this experiment. Results showed that the improved method is suitable not only for genomic DNA extraction of birch but also for that of other plants. The purity of genomic DNA extracted by the multi-times STE-CTAB extraction method is higher than that by one time STE-CTAB method, and it does not need the process of RNase. The factors of influencing ISSR system were explored based on the genomic DNA of birch extracted by the two methods. The optimal conditions for ISSR system were determined as follows: cycles of denaturation for 30 s at 94℃, annealing for 30 s at 51 ℃, extension for 30 s at 72℃, and a final 7 min extension at 72 ℃.

  11. Simultaneous determination of betulin and betulinic acid in white birch bark using RP-HPLC.

    Science.gov (United States)

    Zhao, Guoling; Yan, Weidong; Cao, Dan

    2007-02-19

    A simple procedure is described for the simultaneous extraction and determination of betulin and betulinic acid in white birch bark. The extraction was checked using different solvents: dichloromethane, ethyl acetate, acetone, chloroform, methanol and 95% ethanol (aqueous solution, v/v). It was found 95% ethanol was a good extraction solvent that allowed extraction of triterpenoid with a highest content. Separation was achieved on a reversed phase C(18) column with acetonitrile-water 86:14 (v/v). Detection was accomplished with UV detection at lambda=210 nm. Using this method, the bioactive triterpenoid in white birch bark were simultaneously determined. Significant variations in the content of betulin and betulinic acid in white birch bark growing in different locations of China were also observed.

  12. Temporal and spatiotemporal autocorrelation of daily concentrations of Alnus, Betula, and Corylus pollen in Poland.

    Science.gov (United States)

    Nowosad, J; Stach, A; Kasprzyk, I; Grewling, Ł; Latałowa, M; Puc, M; Myszkowska, D; Weryszko-Chmielewska, E; Piotrowska-Weryszko, K; Chłopek, K; Majkowska-Wojciechowska, B; Uruska, A

    The aim of the study was to determine the characteristics of temporal and space-time autocorrelation of pollen counts of Alnus, Betula, and Corylus in the air of eight cities in Poland. Daily average pollen concentrations were monitored over 8 years (2001-2005 and 2009-2011) using Hirst-designed volumetric spore traps. The spatial and temporal coherence of data was investigated using the autocorrelation and cross-correlation functions. The calculation and mathematical modelling of 61 correlograms were performed for up to 25 days back. The study revealed an association between temporal variations in Alnus, Betula, and Corylus pollen counts in Poland and three main groups of factors such as: (1) air mass exchange after the passage of a single weather front (30-40 % of pollen count variation); (2) long-lasting factors (50-60 %); and (3) random factors, including diurnal variations and measurements errors (10 %). These results can help to improve the quality of forecasting models.

  13. Lipid transfer protein-linked hazelnut allergy in children from a non-Mediterranean birch-endemic area

    NARCIS (Netherlands)

    Flinterman, Annebeth E.; Akkerdaas, Jaap H.; Jager, Constance F. den Hartog; Rigby, Neil M.; Fernandez-Rivas, Montserrat; Hoekstra, Maarten O.; Bruijnzeel-Koomen, Carla A.; Knuist, Andr C.; van Ree, Ronald; Pasmans, Suzanne G.

    2008-01-01

    Background: Hazelnut allergy in birch pollen-exposed areas is usually due to cross-reactivity (Cor a 1 and 2) and is usually mild in nature (oral allergy). In areas without birches, severe reactions are more prevalent and linked to sensitization to the lipid transfer protein (LTP) Cor a 8. Objective

  14. Harvesting wood fuels from mixed stands of hard- and softwood on forest and agricultural land. Final report; Uttag av traedbraensle ur blandbestaand av loev- och barrtraed vaexande paa skogs- och aakermark. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Tord [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Management and Products

    2001-12-01

    The aim was to study the growth of birches (Betula pendula Roth and Betula pubescens Ehrh.) and Norway spruce (Picea abies (L.) Karst.) in mixed stands of birch and spruce, and in pure stands of Norway spruce. Data from nine localities have been analysed. The trials were spread between lat. 56 and 60 deg N. The experiment was established on eight localities in Sweden. Plots in mixed stands of 20-32-year-old birches and Norway spruces were established in 1983-84. Number of stems per hectare, height and diameter of the stems was registered. Then two treatments were made. On a locality all birches in a plot were cut to make pure spruce stands. In another plot 500 birches per hectare were left in the spruce stand for establishing mixed stands. The established stands were then measured. The stands were examined five years later. Stem number, height and diameter was registered. Small corrections in the stands were made eg. birch sprouts were cut and some spruces were cut. In 1996-1998 the stands were examined again. The birch shelter was cut and measured. On one shelter plot per locality 100 birches per hectare was left. The birch shelter was left for making timber production of good quality. The shelter should be cut when the birches are about 60 years old. By the results given in the study there is obvious that MAI for Norway spruce growing for 13-15 years under shelter is lower, 7.2 m{sup 3}/ha/year than for pure spruce stand, 7.9. However the total MAI including birch in the shelter was 11.5 compared with 7.9 m{sup 3}/ha/year in pure spruce stands. Corresponding MAI for biomass in shelter and pure spruce stands was 3.8 and 4.2 ton d.w./ha/year. Total MAI was 6.4 and 4.2 ton/ha/year. A practical implication of the study is that removal of birches when creating mixed stands has too small dimensions for harvesting pulp wood or fuel wood. In the end of the rotation period for mixed stands the birch stems were 16 cm at breast height. These birches could be used as pulp

  15. Analysis of aspen-and-birch separated small woods’ vegetation in North Steppe of Ukraine

    Directory of Open Access Journals (Sweden)

    N. M. Nazarenko

    2010-09-01

    Full Text Available Conducted analysis of forest vegetation has allowed selecting and specifying classification and typological units of the aspen-and-birch separated small woods, which have statistically significant difference of ecotopic and coenotic parameters. Those parameters of studied forest ecosystems are characterised. Existence of the lines of hygrogenic and edaphogenic substitution, and succession rows are described. Phytoindication description of ecological factors’ pivotal conditions is presented. Driving factors determining parameters, structure and composition of the aspen-and-birch forest ecosystems are diminishing soil moisture, increasing annual temperatures amplitude and soil acidity.

  16. Winter warming as an important co-driver for Betula nana growth in western Greenland during the past century

    DEFF Research Database (Denmark)

    Hollesen, Jørgen; Buchwal, Agata; Rachlewicz, Grzegorz;

    2015-01-01

    of thawing and growing degree-days as well as to winter and spring soil temperatures. In addition to these direct effects, a strong negative growth response to sea ice extent was identified, indicating a possible link between local sea ice conditions, local climate variations and Betula nana growth rates...

  17. Solar UV-B effects on PSII performance in Betula nana are influenced by PAR level and reduced by EDU

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, Helge;

    2012-01-01

    The long-term and diurnal responses of photosystem II (PSII) performance to near-ambient UV-B radiation were investigated in High Arctic Betula nana. We conducted an UV exclusion experiment with five replicated blocks consisting of open control (no filter), photosynthetic active radiation and UV...

  18. Carbon gain and bud physiology in Populus tremuloides and Betula papyrifera grown under long-term exposure to elevated concentrations of CO{sub 2} and O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Riikonen, J. [Kuopio Univ., Kuopio (Finland). Dept. of Ecology and Environmental Science; Kets, K.; Sober, A. [Tartu Univ., Tartu (Estonia). Inst. of Botany and Ecology; Darbah, J.; Karnosky, D.F. [Michigan Technical Univ., Houghton, MI (United States). School of Forest Resources and Environmental Science; Oksanen, E. [Joensuu Univ., Joensuu (Finland). Faculty of Biosciences; Vapaavuori, E. [Finnish Forest Research Inst., Suonenjoki (Finland). Suonenjoki Research Inst.; Kubiske, M.E.; Nelson, N. [USDA Forest Service, Rhinelander, WI (United States). Forestry Sciences Laboratory

    2008-02-15

    Elevated carbon dioxide (CO{sub 2}) enhances photosynthesis by increasing carboxylation rates and decreasing the rate of photorespiration. While elevated CO{sub 2} has the potential to increase frost hardiness in trees by increasing bud size and concentrations of cryoprotective soluble sugars in overwintering organs, little is known about the effects of elevated CO{sub 2} on late-season photosynthesis. This study examined 3 trembling aspen (Populus tremuloides) clones and 3 paper birch (Betula papyrifera) grown at a site with elevated CO{sub 2} and ozone (O{sub 3}) applied singly and in combination. Gas exchange was studied throughout the eighth growing season. The study also examined specific leaf area and size in September and final size, carbohydrate, carbon (C), nitrogen (N) and water concentrations in November. The timing of leaf abscission was also studied, as well as bud burst and the development of leaf area index the following Spring. Results of the study showed that net photosynthesis was enhanced by between 49 and 73 per cent with elevated levels of CO{sub 2}, and decreased by between 13 and 30 per cent with elevated O{sub 3}. Elevated CO{sub 2} delayed leaf abscission and increased the ratio of monosaccharides in aspen buds. Total carbon concentrations in overwintering buds were unaffected by the treatments. It was concluded that elevated CO{sub 2} ameliorated the effects of elevated O{sub 2}, but had the potential to alter C metabolism of overwintering buds. 50 refs., 5 tabs., 6 figs.

  19. Medicinal properties of fungi occurring on Betula sp. trees. A review

    Directory of Open Access Journals (Sweden)

    Smolibowska Joanna

    2016-09-01

    Full Text Available The article presents the chemical costituents and pharmacological properties of polyporoid fungi found on birch, namely Piptoporus betulinus, Inonotus obliquus, Lenzites betulina, Fomes fomentarius, and Trametes versicolor. The in vitro and in vivo studies on the effect of different extracts from above-mentioned fungi on the human organism shown anti-cancer, anti-inflammatory, antiviral, antibacterial and immunostimulant activity, conditioned by the presence of such compounds as polysaccharides, polyphenols or terpenes. These fungi are commonly found in Poland and may superbly compete with Ganoderma lucidum (Reishi or Lentinula edodes (Shitake used in Asia for medicinal purposes.

  20. Winter warming as an important co-driver for Betula nana growth in western Greenland during the past century

    Science.gov (United States)

    Hollesen, Jørgen; Buchwal, Agata; Rachlewicz, Grzegorz; Hansen, Birger U; Hansen, Marc O; Stecher, Ole; Elberling, Bo

    2015-01-01

    Growing season conditions are widely recognized as the main driver for tundra shrub radial growth, but the effects of winter warming and snow remain an open question. Here, we present a more than 100 years long Betula nana ring-width chronology from Disko Island in western Greenland that demonstrates a highly significant and positive growth response to both summer and winter air temperatures during the past century. The importance of winter temperatures for Betula nana growth is especially pronounced during the periods from 1910–1930 to 1990–2011 that were dominated by significant winter warming. To explain the strong winter importance on growth, we assessed the importance of different environmental factors using site-specific measurements from 1991 to 2011 of soil temperatures, sea ice coverage, precipitation and snow depths. The results show a strong positive growth response to the amount of thawing and growing degree-days as well as to winter and spring soil temperatures. In addition to these direct effects, a strong negative growth response to sea ice extent was identified, indicating a possible link between local sea ice conditions, local climate variations and Betula nana growth rates. Data also reveal a clear shift within the last 20 years from a period with thick snow depths (1991–1996) and a positive effect on Betula nana radial growth, to a period (1997–2011) with generally very shallow snow depths and no significant growth response towards snow. During this period, winter and spring soil temperatures have increased significantly suggesting that the most recent increase in Betula nana radial growth is primarily triggered by warmer winter and spring air temperatures causing earlier snowmelt that allows the soils to drain and warm quicker. The presented results may help to explain the recently observed ‘greening of the Arctic’ which may further accelerate in future years due to both direct and indirect effects of winter warming. PMID:25788025

  1. Synthesis and characterization of birch wood xylan succinoylated in 1-n-butyl-3-methylimidazolium chloride

    DEFF Research Database (Denmark)

    Hansen, Natanya Majbritt Louie; Plackett, David

    2011-01-01

    The chemical modification of birch wood xylan was undertaken in the ionic liquid 1-n-butyl-3-methylimidazolium chloride (C4mimCl) using three different long-chain succinic anhydrides: n-octenyl succinic anhydride (n-OSA), n-dodecenyl succinic anhydride (n-DDSA) and n-octadecenyl succinic anhydrid...

  2. Differential response of aspen and birch trees to heat stress under elevated carbon dioxide.

    Science.gov (United States)

    Darbah, Joseph N T; Sharkey, Thomas D; Calfapietra, Carlo; Karnosky, David F

    2010-04-01

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO(2) and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO(2) protected photosynthesis of both species against moderate heat stress. Elevated CO(2) increased carboxylation capacity, photosynthetic electron transport capacity, and triose phosphate use in both birch and aspen trees. High temperature (36-39 degrees C) decreased all of these parameters in birch regardless of CO(2) treatment, but only photosynthetic electron transport and triose phosphate use at ambient CO(2) were reduced in aspen. Among the two aspen clones tested, 271 showed higher thermotolerance than 42E possibly because of the higher isoprene-emission, especially under elevated CO(2). Our results indicate that isoprene-emitting trees may have a competitive advantage over non-isoprene emitting ones as temperatures rise, indicating that biological diversity may be affected in some ecosystems because of heat tolerance mechanisms.

  3. Antioxidants from slow pyrolysis bio-oil of birch wood: Application for biodiesel and biobased lubricants

    Science.gov (United States)

    Birch wood was slowly pyrolyzed to produce bio-oil and biochar. Slow pyrolysis conditions including reaction temperature, residence time, and particle size of the feed were optimized to maximize bio-oil yield. Particle size had an insignificant effect, whereas yields of up to 56% were achieved using...

  4. Construction and analysis of a subtracted cDNA library of Betula platyphylla female inflorescence

    Institute of Scientific and Technical Information of China (English)

    WEIJi-cheng; YANGChuan-ping; WANGChao; JIANGJing

    2005-01-01

    Female inflorescence of Betula platyphylla was sampled at an interval of each two days to analyze the background of gene expression in floral phase. On the basis of SMART strategy, the driver cDNA was obtained from total RNA of the last sample and the tester cDNA was from that of the others by RT-PCR which were subsequently used to construct a subtracted cDNA library. The result of the ESTs (expression sequence tags) blastX showed that the genes in the subtracted cDNA library could be mainly clustered into 5 groups related to metabolism, transportation and signal transduction, cell cycle, stress response, and regulation. The relationship between gene expression and development was also discussed.

  5. [Spatial structural characteristics of natural Populus davidiana - Betula platyphylla secondary forest].

    Science.gov (United States)

    Shao, Fang-Li; Yu, Xin-Xiao; Song, Si-Ming; Zhao, Yang

    2011-11-01

    This paper analyzed the spatial structural characteristics of natural Populus davidiana - Betula platyphylla secondary forest in a 4 hm2 plot of Mulan Paddock, based on the diameter distribution and the spatial structure parameters mingling degree, neighborhood comparison, and angle index. In the forest, the diameter distribution of the stands presented as an inverse 'J' curve, the average mingling degree was 0.4, with the individuals at weak and zero mingling degree reached 51.6%, and the average mingling degree of P. davidiana and B. platyphylla was 0.25 and 0.39, respectively. The neighborhood comparison based on the diameter at breast height (DBH) and tree height was almost the same, suggesting that the P. davidiana and B. platyphylla were in the transition state from subdominant to middle. The horizontal distribution pattern had a close relation to the minimum measured DBH, being clustered when the DBH was > or = 1 cm and or = 6 cm.

  6. Allergens from birch pollen and pollen of the European chestnut share common epitopes.

    Science.gov (United States)

    Hirschwehr, R; Jäger, S; Horak, F; Ferreira, F; Valenta, R; Ebner, C; Kraft, D; Scheiner, O

    1993-09-01

    Type I allergy to pollen of the European chestnut (Castanea sativa) represents a major cause of pollinosis in (sub) Mediterranean areas. Using sera from 14 patients with established allergy to pollen of the European chestnut, 13/14 sera (92%) showed IgE-binding to a 22 kD protein, 2/14 (14%) displayed additional binding to a 14 kD protein and 1/14 (7%) bound only to the 14 kD protein of European chestnut pollen extract. Two monoclonal mouse antibodies, BIP 1 and BIP 4, directed against different epitopes of Bet v I (the major birch pollen allergen), and a rabbit antibody to recombinant birch profilin (rBet v II) were used to characterize the proteins of the European chestnut pollen. The recombinant birch pollen allergens, rBet v I and rBet v II (profilin) were employed to show common allergenic structures on proteins from both birch and European chestnut pollen by IgE-inhibition experiments. Despite the fact that the 22 kD protein displayed a higher molecular weight in comparison to the 17 kD major birch pollen allergen, Bet v I, we could demonstrate reactivity of both monoclonal antibodies, BIP 1 and BIP 4, with this protein. A complete inhibiton of IgE-binding to this 22 kD protein was shown by pre-incubating sera with purified recombinant Bet v I. In addition, the 14 kD protein could be identified by IgE-inhibition studies with recombinant Bet v II and by using a rabbit anti-profilin antibody as the profilin from pollen of the European chestnut.

  7. Allometries for Widely Spaced Populus ssp. and Betula ssp. in Nurse Crop Systems

    Directory of Open Access Journals (Sweden)

    Hendrik Stark

    2013-11-01

    Full Text Available Nurse crops of widely spaced pioneer trees are a silvicultural approach to protect the regeneration of frost sensitive target tree species. If overstorey nurse crops are harvested, they can provide additional short-term benefits through increased biomass production, e.g., for bioenergy. However, the intensification of biomass exports from forests might impact negatively on ecosystem nutrient pools. Thus, precise allometric biomass equations are required to quantify biomass and nutrient removals. Since an analysis of published allometric equations developed for typical, dense aspen or birch forests showed that the tree height-to-diameter ratio correlated positively and the proportion of branch biomass negatively with stand density, we developed new allometric biomass equations for widely spaced aspen and birch growing at 4 x 4 m spacing. These equations yielded a root mean squared error of 13% when predicting total aboveground woody biomass for our sample trees. In contrast, the corresponding root mean squared error produced by allometric biomass equations from the literature ranged between 17% to 106% of actual dry biomass. Our results show that specific allometric biomass equations are needed for widely spaced pioneer trees both for accurate estimates of biomass and the nutrients contained within.

  8. Phytoremediation of soils contaminated with phenanthrene and cadmium by growing willow (Salix × aureo-pendula CL 'j1011').

    Science.gov (United States)

    Sun, Y Y; Xu, H X; Li, J H; Shi, X Q; Wu, J C; Ji, R; Guo, H Y

    2016-01-01

    To assess the phytoremediation potential of an autochthonous willow (Salix × aureo-pendula CL 'J1011') for phenanthrene (PHE)-contaminated soils and PHE-cadmium (PHE-Cd) co-contaminated soils, we conducted field experiments in the lower reaches of the Yangtze River, China. Ethylenediaminetetraacetic acid (EDTA) and ethyl lactate were tested for individual and combined effects on the phytoremediation efficiency. For PHE-contaminated soils, willow plus ethyl lactate resulted in significant removal of PHE from soils after 45 days, and the PHE concentration in the shoots was significantly higher with than without ethyl lactate. For PHE-Cd co-contaminated soils, both willow plus EDTA and willow plus EDTA and ethyl lactate led to a significant decrease in the concentrations of PHE and Cd in the soils after 45 days, whereas willow alone did not. The PHE and Cd concentrations in the willow shoots were significantly enhanced in the presence of EDTA alone and with ethyl lactate, except for the PHE concentration in stems with EDTA alone. Under the same treatment, the presence of Cd had no significant influence on the PHE removal from soils. The results indicate the feasibility of using this willow together with both EDTA and ethyl lactate for the simultaneous removal of PHE and Cd from soils.

  9. Forecasting model of Corylus, Alnus, and Betula pollen concentration levels using spatiotemporal correlation properties of pollen count.

    Science.gov (United States)

    Nowosad, Jakub; Stach, Alfred; Kasprzyk, Idalia; Weryszko-Chmielewska, Elżbieta; Piotrowska-Weryszko, Krystyna; Puc, Małgorzata; Grewling, Łukasz; Pędziszewska, Anna; Uruska, Agnieszka; Myszkowska, Dorota; Chłopek, Kazimiera; Majkowska-Wojciechowska, Barbara

    The aim of the study was to create and evaluate models for predicting high levels of daily pollen concentration of Corylus, Alnus, and Betula using a spatiotemporal correlation of pollen count. For each taxon, a high pollen count level was established according to the first allergy symptoms during exposure. The dataset was divided into a training set and a test set, using a stratified random split. For each taxon and city, the model was built using a random forest method. Corylus models performed poorly. However, the study revealed the possibility of predicting with substantial accuracy the occurrence of days with high pollen concentrations of Alnus and Betula using past pollen count data from monitoring sites. These results can be used for building (1) simpler models, which require data only from aerobiological monitoring sites, and (2) combined meteorological and aerobiological models for predicting high levels of pollen concentration.

  10. Effect of Different Pretreatment Methods on Birch Outer Bark: New Biorefinery Routes

    Directory of Open Access Journals (Sweden)

    Anthi Karnaouri

    2016-03-01

    Full Text Available A comparative study among different pretreatment methods used for the fractionation of the birch outer bark components, including steam explosion, hydrothermal and organosolv treatments based on the use of ethanol/water media, is reported. The residual solid fractions have been characterized by ATR-FTIR, 13C-solid-state NMR and morphological alterations after pretreatment were detected by scanning electron microscopy. The general chemical composition of the untreated and treated bark including determination of extractives, suberin, lignin and monosaccharides was also studied. Composition of the residual solid fraction and relative proportions of different components, as a function of the processing conditions, could be established. Organosolv treatment produces a suberin-rich solid fraction, while during hydrothermal and steam explosion treatment cleavage of polysaccharide bonds occurs. This work will provide a deeper fundamental knowledge of the bark chemical composition, thus increasing the utilization efficiency of birch outer bark and may create possibilities to up-scale the fractionation processes.

  11. Proteomic Analysis of Responsive Proteins Induced in Japanese Birch Plantlet Treated with Salicylic Acid

    Science.gov (United States)

    Suzuki, Hiromu; Takashima, Yuya; Ishiguri, Futoshi; Yoshizawa, Nobuo; Yokota, Shinso

    2014-01-01

    The present study was performed to unravel the mechanisms of systemic acquired resistance (SAR) establishment and resistance signaling pathways against the canker-rot fungus (Inonotus obliquus strain IO-U1) infection in Japanese birch plantlet No.8. Modulation of protein-profile induced by salicylic acid (SA)-administration was analyzed, and SA-responsive proteins were identified. In total, 5 specifically expressed, 3 significantly increased, and 3 significantly decreased protein spots were identified using liquid chromatography/tandem mass spectrometry (LC/MS/MS) and the sequence tag method. These proteins were malate dehydrogenase, succinate dehydrogenase, phosphoglycerate kinase, diaminopimalate decarboxylase, arginase, chorismate mutase, cyclophilin, aminopeptidase, and unknown function proteins. These proteins are considered to be involved in SAR-establishment mechanisms in the Japanese birch plantlet No 8.

  12. Properties of plasticized composite films prepared from nanofibrillated cellulose and birch wood xylan

    DEFF Research Database (Denmark)

    Hansen, Natanya Majbritt Louie; Blomfeldt, Thomas O. J.; Hedenqvist, Mikael S.

    2012-01-01

    Xylans, an important sub-class of hemicelluloses, represent a largely untapped resource for new renewable materials derived from biomass. As with other carbohydrates, nanocellulose reinforcement of xylans is interesting as a route to new bio-materials. With this in mind, birch wood xylan was comb......Xylans, an important sub-class of hemicelluloses, represent a largely untapped resource for new renewable materials derived from biomass. As with other carbohydrates, nanocellulose reinforcement of xylans is interesting as a route to new bio-materials. With this in mind, birch wood xylan...... was combined with nanofibrillated cellulose (NFC) and films were cast with and without glycerol, sorbitol or methoxypolyethylene glycol (MPEG) as plasticizers. Microscopy revealed some NFC agglomeration in the composite films as well as a layered nanocellulose structure. Equilibrium moisture content...

  13. Proteomic Analysis of Responsive Proteins Induced in Japanese Birch Plantlet Treated with Salicylic Acid

    Directory of Open Access Journals (Sweden)

    Hiromu Suzuki

    2014-07-01

    Full Text Available The present study was performed to unravel the mechanisms of systemic acquired resistance (SAR establishment and resistance signaling pathways against the canker-rot fungus (Inonotus obliquus strain IO-U1 infection in Japanese birch plantlet No.8. Modulation of protein-profile induced by salicylic acid (SA-administration was analyzed, and SA-responsive proteins were identified. In total, 5 specifically expressed, 3 significantly increased, and 3 significantly decreased protein spots were identified using liquid chromatography/tandem mass spectrometry (LC/MS/MS and the sequence tag method. These proteins were malate dehydrogenase, succinate dehydrogenase, phosphoglycerate kinase, diaminopimalate decarboxylase, arginase, chorismate mutase, cyclophilin, aminopeptidase, and unknown function proteins. These proteins are considered to be involved in SAR-establishment mechanisms in the Japanese birch plantlet No 8.

  14. Analysis and identification of SCAR molecular markers associated with birch fiber length trait

    Institute of Scientific and Technical Information of China (English)

    WANG Dan; WEI Zhi-gang; YANG Chuan-ping; LIU Guan-jun

    2008-01-01

    The fiber length trait (FLT) of 538 individuals from nature birch population in Maorshan region,Heilongjang,China were measured,of which 100 individuals were selected as representative variety of correlated fragments screening with random amplified polymorphism DNA (RAPD) technique.In total of 20 RAPD primers were tested through multiple regression analysis between amplified strip and the character behaviors,and a correlative segment BFLR-16 was obtained.The correlation coefficient between BFLI-16 and FLT was 0.6144,with the significant level of 1%.BFLI-16 was then cloned,sequenced and transformed into SCAR marker.The percentage of identifying long fiber birches by this SCAR was more than 92.The result indicates that the SCAR markers has high specificity for the long fiber individuals and is highly linked with the gene controlling the character of fiber length,and its existence is significantly correlative with the increase in the fiber length.

  15. Influence of Biomass Pretreatment Process Time on Furfural Extraction from Birch Wood

    Science.gov (United States)

    Brazdausks, Prans; Puke, Maris; Vedernikovs, Nikolajs; Kruma, Irena

    2013-12-01

    Furfural is a biomass derived-chemical that can be used to replace petrochemicals. In this study, dilute sulphuric acid hydrolysis was used for hemicelluloses secession from birch wood. The reaction was investigated at different biomass treatment times (10-90 min, increasing it by 10 min). We found that the greatest amount of furfural 1.4-2.6%, which is 9.7-17.7% from theoretical possible yield, was formed in the first 30 min of the beginning of birch wood pentoses monosaccharide dehydration, but the greatest yield of furfural 10.3%, which is 70.0% from the theoretical yield, can be obtained after 90 min. Given that furfural yield generally does not exceed 50% from the theoretical amount, the result can be considered as very good.

  16. Shelf life extension and sensory evaluation of birch tree sap using chemical preservatives

    Directory of Open Access Journals (Sweden)

    Maciej Bilek

    2016-10-01

    Full Text Available The aim of this study was to assess the stability of the birch tree sap, depending on the addition and concentration of two chemical factors, ie. potassium sorbate and acids: malic, citric or lactic. As in our previous studies we found that the optimal physical parameter to assess the stability of birch sap is turbidity measurement, we used turbidimeter for estimate the effectiveness of shelf life extending. Sensory evaluation was carried out by university sensory panel with 8 skilled people (students and teachers with pre-selection and basic training of sensory methodology. On the other hand artificial perception measurements were realized by electronic nose. Birch tree sap stability without addition of preservatives, both room temperature and refrigerated, is less than three days. The effectiveness of preservation of birch tree sap depends on the concentration of acids. Independently of storage temperature, samples that received stability during the whole one-month storage period, were those with potassium sorbate and three acids in the highest concentrations, ie. malic acid at 0.3%, citric acid at 0.5% and lactic acid at 0.5%. Unfortunately, concentrations of acids, which allow extension of shelf life at least for one month in a room temperature, are characterized by the worst sensory evaluation rating. Thus, they should be corrected by the use of additives for improving the flavor, such as fruit syrups or herbal extracts. On the other hand, additionally storage in a refrigerated conditions allows one-month-stability for the sample with the highest sensory evaluation rating, ie. with the addition of lactic acid at 0.1% and potassium sorbate, which taste not need to be corrected.

  17. SYNERGISTIC EFFECTS BETWEEN BIRCH CHEMICAL MECHANICAL PULPS AND ASPEN BLEACHED KRAFT PULP

    Institute of Scientific and Technical Information of China (English)

    Eric C. Xu; Yajun Zhou

    2004-01-01

    In this investigation, two different grades of birch chemical mechanical (P-RC APMP) pulps and aspen market bleached kraft pulp were compared by low consistency refining of the pulps separately and in different combinations. In addition, the separately refined pulps were also combined to compare with the pulps from the co-refined pulp blend. The results showed that in both cases there were synergistic effects between the two types of pulps: adding the birch P-RC APMP pulp to the aspen kraft pulp improved pulp properties, and the resultant pulp blends had a higher fiber bonding strength (tensile and tensile energy absorption) than the sum of weighted contributions from the individual components. Understanding this synergistic effect between chemical mechanical (P-RC APMP) and kraft pulps can help to improve their applications and performances in various papermaking processes.The results also showed that introducing, at least up to certain percentage of, the birch P-RC APMP pulp into the aspen bleached kraft pulp not only improves optical and bulk properties, but also maintains or improves tensile strength, even though the P-RC APMP pulp used has lower tensile than the kraft pulp.

  18. SYNERGISTIC EFFECTS BETWEEN BIRCH CHEMICAL MECHANICAL PULPS AND ASPEN BLEACHED KRAFT PULP

    Institute of Scientific and Technical Information of China (English)

    EricC.Xu; YajunZhou

    2004-01-01

    In this investigation, two different grades of birch chemical mechanical (P-RC APMP) pulps and aspen market bleached kraft pulp were compared by low consistency refining of the pulps separately and in different combinations. In addition, the separately refined pulps were also combined to compare with the pulps from the co-refined pulp blend. The results showed that in both cases there were synergistic effects between the two types of pulps: adding the birch P-RC APMP pulp to the aspen kraft pulp improved pulp properties, and the resultant pulp blends had a higher fiber bonding strength (tensile and tensile energy absorption) than the sum of weighted contributions from the individual components. Understanding this synergistic effect between chemical mechanical (P-RC APMP) and kraft pulps can help to improve their applications and performances in various papermaking processes. The results also showed that introducing, at least up to certain percentage of, the birch P-RC APMP pulp into the aspen bleached kraft pulp not only improves optical and bulk properties, but also maintains or improves tensile strength, even though the P-RC APMP pulp used has lower tensile than the kraft pulp.

  19. EFFECT OF THERMAL TREATMENT ON THE CHEMICAL COMPOSITION AND MECHANICAL PROPERTIES OF BIRCH AND ASPEN

    Directory of Open Access Journals (Sweden)

    Duygu Kocaefe

    2008-05-01

    Full Text Available The high temperature treatment of wood is one of the alternatives to chemical treatment. During this process, the wood is heated to higher temperatures than those of conventional drying. The wood structure changes due to decomposition of hemicelluloses, ramification of lignin, and crystallization of cellulose. The wood becomes less hygroscopic. These changes improve the dimensional stability of wood, increase its resistance to micro-organisms, darken its color, and modify its hardness. However, wood also might loose some of its elasticity. Consequently, the heat treatment conditions have to be optimized. Therefore, it is important to understand the transformation of the chemical structure of wood caused by the treatment. In this study, the modification of the surface composition of the wood was followed with Fourier transform infrared spectroscopy (FTIR and inverse gas chromatography (IGC under different experimental conditions. The effect of maximum treatment temperatures on the chemical composition of Canadian birch and aspen as well as the correlations between their chemical transformation and different mechanical properties are presented. FTIR analysis results showed that the heat treatment affected the chemical composition of birch more compared to that of aspen. The results of IGC tests illustrated that the surfaces of the aspen and birch became more basic with heat treatment. The mechanical properties were affected by degradation of hemicellulose, ramification of lignin and cellulose crystallization.

  20. Mountain birch – potentially large source of sesquiterpenes into high latitude atmosphere

    Directory of Open Access Journals (Sweden)

    S. Haapanala

    2009-06-01

    Full Text Available Emissions of volatile organic compounds (VOCs from mountain birches were measured in Abisko, northern Sweden. Mountain birches make up majority of the tree biomass in Scandinavian high latitudes, area subject to significant climate warming. The measurements were carried out in two growing seasons. The emissions of a branch from four individual trees were measured in June–August 2006 and one of them again in July 2007. The measurements were conducted using a dynamic flow through chamber covered with Teflon film. The studied mountain birches were found to emit substantial amounts of linalool, monoterpenes and sesquiterpenes. The monoterpene emission was dominated by sabinene. The magnitude and composition of sesquiterpene emission changed dramatically between the years. For example, the average α-farnesene emission in 2006 was almost 2000 ng gdw−1 h−1 while in 2007 the emission of α-farnesene was negligible. Also the emissions of other sesquiterpenes decreased in 2007 to a fraction of that in 2006. One possible explanation for the change in emissions is the herbivory damage that occurred in the area in 2004. Herbivory is known to enhance the emissions of sesquiterpenes, especially those of α-farnesene, and the effect may last several years.

  1. Mountain birch – potentially large source of sesquiterpenes into high latitude atmosphere

    Directory of Open Access Journals (Sweden)

    A. Arneth

    2009-11-01

    Full Text Available Emissions of volatile organic compounds (VOCs from mountain birches were measured in Abisko, northern Sweden. Mountain birches make up the majority of the tree biomass in Scandinavian high latitudes, a region subject to significant climate warming. The measurements were carried out in two growing seasons. The emissions of four branches, each from a different individual tree, were measured in June–August 2006 and one of them again in July 2007. The measurements were conducted using a dynamic flow through chamber covered with Teflon film. The studied mountain birches were found to emit substantial amounts of linalool, monoterpenes and sesquiterpenes. The monoterpene emission was dominated by sabinene. The magnitude and composition of the sesquiterpene emission changed dramatically between the years. For example, the average α-farnesene emission potential in 2006 was almost 2600 ng gdw−1 h−1 (3.5 pmol gdw−1 s−1 while in 2007 α-farnesene was not detected at all. Also the emissions of other sesquiterpenes decreased in 2007 to a fraction of that in 2006. One possible explanation for the change in emissions is the herbivory damage that occurred in the area in 2004. Herbivory is known to enhance the emissions of sesquiterpenes, especially those of α-farnesene, and the effect may last for several years.

  2. Quantification of lignin-carbohydrate linkages with high-resolution NMR spectroscopy.

    Science.gov (United States)

    Balakshin, Mikhail; Capanema, Ewellyn; Gracz, Hanna; Chang, Hou-min; Jameel, Hasan

    2011-06-01

    A quantitative approach to characterize lignin-carbohydrate complex (LCC) linkages using a combination of quantitative ¹³C NMR and HSQC 2D NMR techniques has been developed. Crude milled wood lignin (MWLc), LCC extracted from MWLc with acetic acid (LCC-AcOH) and cellulolytic enzyme lignin (CEL) preparations were isolated from loblolly pine (Pinus taeda) and white birch (Betula pendula) woods and characterized using this methodology on a routine 300 MHz NMR spectrometer and on a 950 MHz spectrometer equipped with a cryogenic probe. Structural variations in the pine and birch LCC preparations of different types (MWL, CEL and LCC-AcOH) were elucidated. The use of the high field NMR spectrometer equipped with the cryogenic probe resulted in a remarkable improvement in the resolution of the LCC signals and, therefore, is of primary importance for an accurate quantification of LCC linkages. The preparations investigated showed the presence of different amounts of benzyl ether, γ-ester and phenyl glycoside LCC bonds. Benzyl ester moieties were not detected. Pine LCC-AcOH and birch MWLc preparations were preferable for the analysis of phenyl glycoside and ester LCC linkages in pine and birch, correspondingly, whereas CEL preparations were the best to study benzyl ether LCC structures. The data obtained indicate that pinewood contains higher amounts of benzyl ether LCC linkages, but lower amounts of phenyl glycoside and γ-ester LCC moieties as compared to birch wood.

  3. Disappearing population of Betula humilis Schrk. on the Maliszewskie Lake, NE Poland

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    Chrzanowska Agnieszka

    2015-03-01

    Full Text Available Betula humilis Schrk. is an endangered glacial relict inhabiting wet meadows, natural and drained fens. One of its declining populations is located on the Maliszewskie Lake (the Wizna swamp, north-eastern Poland. The goal of the present study was to estimate the number of B. humilis individuals in this locality. In the Maliszewskie Lake population, 59 ramets, grouped into three clusters, were found. Twelve nuclear microsatellite loci were chosen to genotype 52 ramets. The analysis revealed that all the shoots within the single cluster had the same genotypes at the loci considered. This means that each cluster constituted one genetically distinct individual; thus, there were only three individuals of B. humilis in the studied population. The maintenance of the B. humilis population in the Maliszewskie Lake area requires urgent active protection involving removal of the shading vegetation. In fact, the entire Maliszewskie Lake is worthy of protection because of its hitherto unexplained origin and the occurrence of many endangered bird species.

  4. Below-ground carbon transfer among Betula nana may increase with warming in Arctic tundra.

    Science.gov (United States)

    Deslippe, Julie R; Simard, Suzanne W

    2011-11-01

    • Shrubs are expanding in Arctic tundra, but the role of mycorrhizal fungi in this process is unknown. We tested the hypothesis that mycorrhizal networks are involved in interplant carbon (C) transfer within a tundra plant community. • Here, we installed below-ground treatments to control for C transfer pathways and conducted a (13)CO(2)-pulse-chase labelling experiment to examine C transfer among and within plant species. • We showed that mycorrhizal networks exist in tundra, and facilitate below-ground transfer of C among Betula nana individuals, but not between or within the other tundra species examined. Total C transfer among conspecific B. nana pairs was 10.7 ± 2.4% of photosynthesis, with the majority of C transferred through rhizomes or root grafts (5.2 ± 5.3%) and mycorrhizal network pathways (4.1 ± 3.3%) and very little through soil pathways (1.4 ± 0.35%). • Below-ground C transfer was of sufficient magnitude to potentially alter plant interactions in Arctic tundra, increasing the competitive ability and mono-dominance of B. nana. C transfer was significantly positively related to ambient temperatures, suggesting that it may act as a positive feedback to ecosystem change as climate warms.

  5. Growth and nutrient efficiency of Betula alnoides clones in response to phosphorus supply

    Directory of Open Access Journals (Sweden)

    Lin Chen

    2016-12-01

    Full Text Available As phosphorus deficiency limits the productivity of many plantation forests in Asia, there is considerable interest in developing phosphorus-efficient clones for the region through targeted breeding programs. Therefore, we determined growth, nutrient concentrations and nutrient absorption and utility efficiencies of four Betula alnoides clones (C5, C6, 1-202 and BY1 in response to six phosphorus levels of 0, 17, 52, 70, 140 and 209 mg P plant-1 coded as P1 to P6, respectively. Maximum growth occurred in the P4, P5 and P6 plants since they had the largest height, biomass, leaf area and branch number. Phosphorus application increased the phosphorus concentrations of all clones. Nutrient loading was achieved with the P6 treatment because growth and biomass were not significantly higher, but root, stem and leaf phosphorus concentrations were approximately twice those of P4 plants. Clone BY1 had the highest phosphorus-efficiency, and is recommended for field application due to its maximum root collar diameter, biomass, root/shoot ratio, leaf area, nutrient absorption and utility efficiency among the four clones. The findings will help to improve the nutrient efficiency of this species in plantation forestry in Asia.

  6. Seventeen-year trends in spring and autumn phenophases of Betula pubescens in a boreal environment

    Science.gov (United States)

    Poikolainen, Jarmo; Tolvanen, Anne; Karhu, Jouni; Kubin, Eero

    2016-08-01

    Trends in the timing of spring and autumn phenophases of Betula pubescens were investigated in the southern, middle, and northern boreal zones in Finland. The field observations were carried out at 21 sites in the Finnish National Phenological Network in 1997-2013. The effective temperature sum of the thermal growth period, i.e. the sum of the positive differences between diurnal mean temperatures and 5 °C (ETS1), increased annually on average by 6-7 degree day units. Timing of bud burst remained constant in the southern and middle boreal zones but advanced annually by 0.5 day in the northern boreal zone. The effective temperature sum at bud burst (ETS2) showed no trend in the southern and middle boreal zones, whereas ETS2 increased on average from 20-30 to 50 degree day units in the northern boreal zone, almost to the same level as in the other zones. Increase in ETS2 indicates that the trees did not start their growth in very early spring despite warmer spring temperatures. The timing of leaf colouring and leaf fall remained almost constant in the southern boreal zones, whereas these advanced annually by 0.3 and 0.6 day in the middle boreal zone and by 0.6 and 0.4 day in the northern boreal zone, respectively. The duration of the growth period remained constant in all boreal zones. The results indicate high buffering capacity of B. pubescens against temperature changes. The study also shows the importance of the duration of phenological studies: some trends in spring phenophases had levelled out, while new trends in autumn phases had emerged after earlier studies in the same network for a shorter observation period.

  7. Community structure and regeneration types of Betula dahurica forest in Badaling forest center of Beijing

    Institute of Scientific and Technical Information of China (English)

    Zhang Yong; Zheng Zhi-hua; Zhang Zhi-xiang

    2007-01-01

    Using plant community analysis methods, we analyzed the floristic characteristics, species composition, community structure, population structure, and spatial distribution patterns of a Betula dahurica forest on the "1238" mountain of Badaling in Beijing, China. The results show that: 1) There are 33 plant species in the B. dahurica community, including 18 woody plant species. The B. dahurica forest is a monodominant community with 75.9% dominance. 2) Based on diameter at breast height (DBH)size class distribution, the population structure of B. dahurica and Acer mono-two heliophyllous and pioneer tree species is cascade-type, with both in an increasing stage. The population structure of Tilia mandshurica and T. mongolica, two shade-tolerant tree species, is inverse-J type, and they have more young seedling individuals and regenerate more stably. They are associated species of the pioneer tree species. The population structure of Quercus mongolica, as the associated species of climax species in the community, is sporadic, and its regeneration is fluctuating and random. Fraxinus rhynchophylla is a shade-tolerant tree species which has a unibar population structure and climax characteristics of pioneer tree species. The relative frequency of young seedlings reached 0.4.3) The dominant species B. dahurica is still in an increasing stage, and the regeneration of other species is steady or partly influences the community, putting the community in the pioneer species stage. From the population structure and distribution frequency ofF. rhynchophylla, the B. dahurica forest will approach to a climax state in the future.

  8. Progeny test of tetraploid Betula platyphylla and preliminary selection of hybrid parents

    Institute of Scientific and Technical Information of China (English)

    Huanwen Xu; Yu Liu; Jing Jiang; Guifeng Liu; Xiyang Zhao

    2016-01-01

    Estimating genetic parameters of parental lines through progeny testing and choosing good hybrid parents are important for genetically improving seed orchard trees. In this study, 24 tetraploid progeny seedlings were used as experimental materials, which came from test cross design:six tetraploid Betula platyphylla lines (Q33, Q13, Q103, Q19, Q83 and Q14) as female parents and four individual B. platyphylla diploid lines (F3, F4, F9 and F11) as male parents were crossed. Variance analysis of height, diame-ter, height-to-diameter ratio, and internodal distance showed that the differences between hybrid combinations reached highly significant levels. Using multi-objective decisionmaking, we performed a comprehensive assess-ment of the various hybrid combinations. Using a selection rate of 20% of the standard, five hybrids were selected;their genetic gains in average height, diameter, height-to-diameter ratio, and internodal distance were 20.95, 6.07, 13.07 and 8.96%, respectively. We also analyzed the combining ability and genetic parameter effect values of parents and hybrid combinations. The combined analysis revealed that Q13, Q103, Q33 and Q83 were superior females; F3, F4, and F9 were superior males; and F3 9 Q13, F4 9 Q83 and F9 9 Q33 were superior hybrid combinations. The heights and diameters of these proge-nies were 22.49 and 11.48% greater than average, respectively.

  9. Isolation and identification of plant phenolic compounds in birch leaves: Air pollution stress and leaf phenolics

    Science.gov (United States)

    Loponen, Jyrki Mikael

    Chromatographic (analytical and preparative HPLC), chemical (hydrolysis) and spectroscopic (UV, 1H NMR, 13C NMR and MS) techniques proved to be suitable tools for the structure identification of plant phenolic compounds. More than 30 individual phenolic compounds were detected and quantified. Detailed information of the structures of individual compounds was determined after isolation from birch leaves. Ten flavonoid glycosides were identified. Two of them, myricetin-3-O-α-L-(acetyl)-rhamnopyranoside and quercetin-3-O-α-L-(4/prime'-O-acetyl)- rhamnopyranoside, have been rarely found in birch leaves. Further, some characterized major phenolics with non- flavonoid structures in our study were 1-O-galloyl- β-D-(2-O-acetyl)-glucopyranose, gallic, chlorogenic, neochlorogenic, cis- and trans-forms of 3- and 5-p-coumaroylquinic acids. The presence of gallotannin group was evidenced by strong positive correlations between concentrations of these gallotannins (preliminary identified by HPLC and UV spectra) and the protein precipitation capacity of extracts. Content of gallotannins decreased with leaf growth and maturation. It is known that concentrations of phenolic compounds regularly increase in slowly growing stressed plants and therefore, it is natural that they are also sensitive to different forms of air pollution. Total content and the contents of some individual phenolics correlated negatively with the distance from the pollution source in our study area. In addition to comparing absolute concentrations of compounds in question, the within-tree correlations or within-tree variations of the relevant compounds between polluted and control areas were an alternative approach. Differences in pairwise correlations between the investigated leaf phenolic compounds indicated the competition between some gallotannins and p-coumaroylquinic acids on the polluted but not on the control site. Air pollution seems to be a stress factor for birch trees associated with

  10. High environmental ozone levels lead to enhanced allergenicity of birch pollen.

    Directory of Open Access Journals (Sweden)

    Isabelle Beck

    Full Text Available BACKGROUND: Evidence is compelling for a positive correlation between climate change, urbanisation and prevalence of allergic sensitisation and diseases. The reason for this association is not clear to date. Some data point to a pro-allergenic effect of anthropogenic factors on susceptible individuals. OBJECTIVES: To evaluate the impact of urbanisation and climate change on pollen allergenicity. METHODS: Catkins were sampled from birch trees from different sites across the greater area of Munich, pollen were isolated and an urbanisation index, NO2 and ozone exposure were determined. To estimate pollen allergenicity, allergen content and pollen-associated lipid mediators were measured in aqueous pollen extracts. Immune stimulatory and modulatory capacity of pollen was assessed by neutrophil migration assays and the potential of pollen to inhibit dendritic cell interleukin-12 response. In vivo allergenicity was assessed by skin prick tests. RESULTS: The study revealed ozone as a prominent environmental factor influencing the allergenicity of birch pollen. Enhanced allergenicity, as assessed in skin prick tests, was mirrored by enhanced allergen content. Beyond that, ozone induced changes in lipid composition and chemotactic and immune modulatory potential of the pollen. Higher ozone-exposed pollen was characterised by less immune modulatory but higher immune stimulatory potential. CONCLUSION: It is likely that future climate change along with increasing urbanisation will lead to rising ozone concentrations in the next decades. Our study indicates that ozone is a crucial factor leading to clinically relevant enhanced allergenicity of birch pollen. Thus, with increasing temperatures and increasing ozone levels, also symptoms of pollen allergic patients may increase further.

  11. Adaptive Responses of Birch-Leaved Pear (Pyrus betulaefolia Seedlings to Salinity Stress

    Directory of Open Access Journals (Sweden)

    Qiang Sheng WU

    2009-06-01

    Full Text Available One-year-old birch-leaved pear (Pyrus betulaefolia Bunge seedlings were subjected to 0, 50, 100, 150, and 200 mmol/L NaCl solutions for 27 days in order to study the effects of salinity stress on photosynthesis, ion accumulation and enzymatic and non-enzymatic scavenging of reactive oxygen species in the seedlings. The research was performed in a greenhouse using potted trees. Salinity stress reduced photosynthetic rates, stomatal conductance and water use efficiency of leaves of the pear seedlings, but increased transpiration rates and leaf temperature. Hydrogen peroxide and superoxide anion radical contents increased with increasing NaCl concentrations, a phenomena also observed for malondialdehyde, suggesting that leaves of the pear seedlings suffered from oxidative injury. Superoxide dismutase (SOD and catalase (CAT activities quickly responded by increasing when the pear seedlings were subjected to salinity stress. Total protein content in leaves of the seedlings was restrained by salinity stress, whereas ascorbate content increased. Salinity stress reduced glutathione content once the birch-leaved pear seedlings were exposed to a low level (50 or 100 mmol/L of NaCl, whereas a high level (150 or 200 mmol/L NaCl of salinity stress stimulated the accumulation of glutathione. Salinity stress increased the accumulation of Na+, Cl-, K+ and Mg2+ in the seedlings, but reduced Ca2+ levels and the ratio of other ions to Na+ except K+/Na+ under 50 mmol/L NaCl conditions. This suggests that leaves of birch-leaved pear seedlings possess the capacity for salt exclusion only under 50 mmol/L NaCl conditions, and Ca2+ does not play a fundamental role as a secondary messenger under salinity stress conditions.

  12. Ara h 8, a Bet v 1-homologous allergen from peanut, is a major allergen in patients with combined birch pollen and peanut allergy

    NARCIS (Netherlands)

    Mittag, D.; Akkerdaas, J.; Ballmer-Weber, B.K.; Vogel, L.; Wensing, M.; Becker, W.M.; Koppelman, S.J.; Knulst, A.C.; Helbling, A.; Hefle, S.L.; Ree, R. van; Vieths, S.

    2004-01-01

    We recently described patients with soybean allergy mainly mediated by cross-reactivity to birch pollen allergens. A majority of those patients were reported to have peanut allergy. We sought to study the occurrence of peanut allergy in patients allergic to birch pollen and characterized the Bet v 1

  13. The safety and efficacy of subcutaneous birch pollen immunotherapy - a one-year, randomised, double-blind, placebo-controlled study

    DEFF Research Database (Denmark)

    Bødtger, U; Poulsen, Lars K.; Jacobi, H H

    2002-01-01

    There is only very limited documentation of the efficacy and safety of high-dose subcutaneous birch pollen immunotherapy (IT) in double-blind, placebo-controlled (DBPC) studies. Birch pollen is a major cause of allergic morbidity in northern Europe and in eastern parts of North America....

  14. Moth outbreaks alter root-associated fungal communities in subarctic mountain birch forests.

    Science.gov (United States)

    Saravesi, Karita; Aikio, Sami; Wäli, Piippa R; Ruotsalainen, Anna Liisa; Kaukonen, Maarit; Huusko, Karoliina; Suokas, Marko; Brown, Shawn P; Jumpponen, Ari; Tuomi, Juha; Markkola, Annamari

    2015-05-01

    Climate change has important implications on the abundance and range of insect pests in forest ecosystems. We studied responses of root-associated fungal communities to defoliation of mountain birch hosts by a massive geometrid moth outbreak through 454 pyrosequencing of tagged amplicons of the ITS2 rDNA region. We compared fungal diversity and community composition at three levels of moth defoliation (intact control, full defoliation in one season, full defoliation in two or more seasons), replicated in three localities. Defoliation caused dramatic shifts in functional and taxonomic community composition of root-associated fungi. Differentially defoliated mountain birch roots harbored distinct fungal communities, which correlated with increasing soil nutrients and decreasing amount of host trees with green foliar mass. Ectomycorrhizal fungi (EMF) abundance and richness declined by 70-80 % with increasing defoliation intensity, while saprotrophic and endophytic fungi seemed to benefit from defoliation. Moth herbivory also reduced dominance of Basidiomycota in the roots due to loss of basidiomycete EMF and increases in functionally unknown Ascomycota. Our results demonstrate the top-down control of belowground fungal communities by aboveground herbivory and suggest a marked reduction in the carbon flow from plants to soil fungi following defoliation. These results are among the first to provide evidence on cascading effects of natural herbivory on tree root-associated fungi at an ecosystem scale.

  15. Adhesive Through-Reinforcement Improves the Fracture Toughness of a Laminated Birch Wood Composite

    Directory of Open Access Journals (Sweden)

    Wenchang He

    2017-01-01

    Full Text Available In this paper we test the hypothesis that adhesive through-reinforcement in combination with glass-fibre reinforcement of adhesive bond lines will significantly improve the fracture toughness of a laminated birch wood composite. We test this hypothesis using a model composite consisting of perforated veneer that allowed a polyurethane adhesive to penetrate and reinforce veneers within the composite. Model composite specimens were tested for mode I fracture properties, and scanning electron microscopy was used to examine the microstructure of fracture surfaces. Our results clearly show that through-reinforcement, and also reinforcing adhesive bond lines with glass-fibre, significantly improved fracture toughness of the birch wood composite. Our results also indicate that improvements in fracture toughness depended on the level of reinforcement. Improvements in fracture toughness were related to the ability of the reinforcement to arrest crack development during fracture testing and the fibre bridging effect of glass-fibre in adhesive bond lines. We conclude that through-reinforcement is an effective way of improving the fracture toughness of laminated wood composites, but further research is needed to develop practical ways of creating such reinforcement in composites that more closely resemble commercial products.

  16. [Spatial patterns of dominant tree species in sub-alpine Betula-Abies forest in West Sichuan of China].

    Science.gov (United States)

    Miao, Ning; Liu, Shi-Rong; Shi, Zuo-Min; Yu, Hong; Liu, Xing-Liang

    2009-06-01

    Based on the investigation in a 4 hm2 Betula-Abies forest plot in sub-alpine area in West Sichuan of China, and by using point pattern analysis method in terms of O-ring statistics, the spatial patterns of dominant species Betula albo-sinensis and Abies faxoniana in different age classes in study area were analyzed, and the intra- and inter-species associations between these age classes were studied. B. albo-sinensis had a unimodal distribution of its DBH frequency, indicating a declining population, while A. faxoniana had a reverse J-shaped pattern, showing an increasing population. All the big trees of B. albo-sinensis and A. faxoniana were spatially in random at all scales, while the medium age and small trees were spatially clumped at small scales and tended to be randomly or evenly distributed with increasing spatial scale. The maximum aggregation degree decreased with increasing age class. Spatial association mainly occurred at small scales. A. faxoniana generally showed positive intra-specific association, while B. albo-sinensis generally showed negative intra-specific association. For the two populations, big and small trees had no significant spatial association, but middle age trees had negative spatial association. Negative inter-specific associations of the two populations were commonly found in different age classes. The larger the difference of age class, the stronger the negative inter-specific association.

  17. Flavonoids in the leaves of Polish species of the genus Betula L. IV. The flavonoids of Betula pubescens Ehrh., B. carpatica Waldst., B. tortuosa Ledeb., and B. nana L. leaves

    Directory of Open Access Journals (Sweden)

    Lucyna Pawłowska

    2014-01-01

    Full Text Available Besides the flavonoids detected earlier, the leaves of purebred B. pubescens specimens were found to contain quercetin 3-arabinoside, isorhamnetin 3-galactoside, luteolin 4'-glucoside, isoquercitrin, acacetin 7-glucoside, and perhaps scutellarein 7-glycoside, whereas B. nana exhibited a low content of myricetin 3-galactoside and quercetin 3-arabinoside, and also possibly quercetin 7-rhamnoside. The qualitative composition of the flavonoids of desiccated B. tortuosa leaves seems to point to the validity of the assumption that this birch is of hybrid origin. The set of flavonoids in B. carpatica was almost identical with that in B. tortuosa.

  18. Academic Success for Students of Color . . . At What Cost? The Importance of School Context at Birch High School

    Science.gov (United States)

    Chambers, Terah T. Venzant; Tabron, Lolita A.

    2013-01-01

    Kiara, an African American rising freshman, has aspirations to become a medical doctor. She enrolls at Birch High School because of the reputation of the principal, Mr. Brown, whose vision for academic excellence permeates every corner of the school. Kiara graduates from high school with top honors, but realizes her success may have come at a…

  19. An investigation of the possible immunological relationship between allergen extracts from birch pollen, hazelnut, potato and apple

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Løwenstein, H

    1978-01-01

    In a retrospective study on selected group of patients, the coincidence of birch pollen allergy and a clinically relevant positive prick test reaction to apples and potatoes was confirmed. Immunochemical comparison using the crossed line immunoelectrophoresis technique (CLIE) confirmed partial id...

  20. Birch Bark Dry Extract by Supercritical Fluid Technology: Extract Characterisation and Use for Stabilisation of Semisolid Systems

    Directory of Open Access Journals (Sweden)

    Markus Armbruster

    2017-03-01

    Full Text Available Triterpene compounds like betulin, betulinic acid, erythrodiol, oleanolic acid and lupeol are known for many pharmacological effects. All these substances are found in the outer bark of birch. Apart from its pharmacological effects, birch bark extract can be used to stabilise semisolid systems. Normally, birch bark extract is produced for this purpose by extraction with organic solvents. Employing supercritical fluid technology, our aim was to develop a birch bark dry extract suitable for stabilisation of lipophilic gels with improved properties while avoiding the use of toxic solvents. With supercritical carbon dioxide, three different particle formation methods from supercritical solutions have been tested. First, particle deposition was performed from a supercritical solution in an expansion chamber. Second, the Rapid Expansion of Supercritical Solutions (RESS method was used for particle generation. Third, a modified RESS-procedure, forming the particles directly into the thereby gelated liquid, was developed. All three methods gave yields from 1% to 5.8%, depending on the techniques employed. The triterpene composition of the three extracts was comparable: all three gave more stable oleogels compared to the use of an extract obtained by organic solvent extraction. Characterizing the rheological behaviour of these gels, a faster gelling effect was seen together with a lower concentration of the extract required for the gel formation with the supercritical fluid (SCF-extracts. This confirms the superiority of the supercritical fluid produced extracts with regard to the oleogel forming properties.

  1. Purification and characterization of natural Bet v 1 from birch pollen and related allergens from carrot and celery

    NARCIS (Netherlands)

    Bollen, M.A.; Garcia, A.; Cordewener, J.H.G.; Wichers, H.J.; Helsper, J.P.F.G.; Savelkoul, H.F.J.; Boekel, van M.A.J.S.

    2007-01-01

    Birch pollen allergy is predominantly caused by the major allergen Bet v 1 and can lead to crossreactions with homologous proteins in food. Two major cross-reactive food allergens are Dau c 1 from carrot and Api g 1 from celery, which have never been purified from their natural source. Here, we desc

  2. Release of Bet v 1 from birch pollen from 5 European countries. Results from the HIALINE study

    Science.gov (United States)

    The HIALINE working Group; Buters, Jeroen T. M.; Thibaudon, Michel; Smith, Matt; Kennedy, Roy; Rantio-Lehtimäki, Auli; Albertini, Roberto; Reese, Gerald; Weber, Bernhard; Galan, Carmen; Brandao, Rui; Antunes, Celia M.; Jäger, Siegfried; Berger, Uwe; Celenk, Sevcan; Grewling, Łukasz; Jackowiak, Bogdan; Sauliene, Ingrida; Weichenmeier, Ingrid; Pusch, Gudrun; Sarioglu, Hakan; Ueffing, Marius; Behrendt, Heidrun; Prank, Marje; Sofiev, Mikhail; Cecchi, Lorenzo

    2012-08-01

    Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content of ambient air is unknown. We therefore monitored atmospheric concentrations of birch pollen grains and the matched major birch pollen allergen Bet v 1 simultaneously across Europe within the EU-funded project HIALINE (Health Impacts of Airborne Allergen Information Network).Pollen count was assessed with Hirst type pollen traps at 10 l min-1 at sites in France, United Kingdom, Germany, Italy and Finland. Allergen concentrations in ambient air were sampled at 800 l min-1 with a Chemvol® high-volume cascade impactor equipped with stages PM > 10 μm, 10 μm > PM > 2.5 μm, and in Germany also 2.5 μm > PM > 0.12 μm. The major birch pollen allergen Bet v 1 was determined with an allergen specific ELISA. Bet v 1 isoform patterns were analyzed by 2D-SDS-PAGE blots and mass spectrometric identification. Basophil activation was tested in an FcɛR1-humanized rat basophil cell line passively sensitized with serum of a birch pollen symptomatic patient.Compared to 10 previous years, 2009 was a representative birch pollen season for all stations. About 90% of the allergen was found in the PM > 10 μm fraction at all stations. Bet v 1 isoforms pattern did not vary substantially neither during ripening of pollen nor between different geographical locations. The average European allergen release from birch pollen was 3.2 pg Bet v 1/pollen and did not vary much between the European countries. However, in all countries a >10-fold difference in daily allergen release per pollen was measured which could be explained by long-range transport of pollen with a deviating allergen release. Basophil activation by ambient air extracts correlated better with airborne allergen than with pollen concentration.Although Bet v 1 is a mixture of different

  3. Glutathione-S-transferase: a minor allergen in birch pollen due to limited release from hydrated pollen.

    Directory of Open Access Journals (Sweden)

    Stephan Deifl

    Full Text Available Recently, a protein homologous to glutathione-S-transferases (GST was detected in prominent amounts in birch pollen by proteomic profiling. As members of the GST family are relevant allergens in mites, cockroach and fungi we investigated the allergenic relevance of GST from birch (bGST.bGST was expressed in Escherichia coli, purified and characterized by mass spectrometry. Sera from 217 birch pollen-allergic patients were tested for IgE-reactivity to bGST by ELISA. The mediator-releasing activity of bGST was analysed with IgE-loaded rat basophil leukaemia cells (RBL expressing human FcεRI. BALB/c mice were immunized with bGST or Bet v 1. Antibody and T cell responses to either protein were assessed. IgE-cross-reactivity between bGST with GST from house dust mite, Der p 8, was studied with murine and human sera in ELISA. The release kinetics of bGST and Bet v 1 from birch pollen were assessed in water, simulated lung fluid, 0.9% NaCl and PBS. Eluted proteins were quantified by ELISA and analysed by immunoblotting.Only 13% of 217 birch pollen-allergic patients showed IgE-reactivity to bGST. In RBL assays bGST induced mediator release. Immunization of mice with bGST induced specific IgE and a Th2-dominated cellular immune response comparably to immunization with Bet v 1. bGST did not cross-react with Der p 8. In contrast to Bet v 1, only low amounts of bGST were released from pollen grains upon incubation in water and the different physiological solutions.Although bGST is abundant in birch pollen, immunogenic in mice and able to induce mediator release from effector cells passively loaded with specific IgE, it is a minor allergen for birch pollen-allergic patients. We refer this discrepancy to its limited release from hydrated pollen. Hence, bGST is an example demonstrating that allergenicity depends mainly on rapid elution from airborne particles.

  4. Winter warming as an important co-driver for Betula nana growth in western Greenland during the past century.

    Science.gov (United States)

    Hollesen, Jørgen; Buchwal, Agata; Rachlewicz, Grzegorz; Hansen, Birger U; Hansen, Marc O; Stecher, Ole; Elberling, Bo

    2015-06-01

    Growing season conditions are widely recognized as the main driver for tundra shrub radial growth, but the effects of winter warming and snow remain an open question. Here, we present a more than 100 years long Betula nana ring-width chronology from Disko Island in western Greenland that demonstrates a highly significant and positive growth response to both summer and winter air temperatures during the past century. The importance of winter temperatures for Betula nana growth is especially pronounced during the periods from 1910-1930 to 1990-2011 that were dominated by significant winter warming. To explain the strong winter importance on growth, we assessed the importance of different environmental factors using site-specific measurements from 1991 to 2011 of soil temperatures, sea ice coverage, precipitation and snow depths. The results show a strong positive growth response to the amount of thawing and growing degree-days as well as to winter and spring soil temperatures. In addition to these direct effects, a strong negative growth response to sea ice extent was identified, indicating a possible link between local sea ice conditions, local climate variations and Betula nana growth rates. Data also reveal a clear shift within the last 20 years from a period with thick snow depths (1991-1996) and a positive effect on Betula nana radial growth, to a period (1997-2011) with generally very shallow snow depths and no significant growth response towards snow. During this period, winter and spring soil temperatures have increased significantly suggesting that the most recent increase in Betula nana radial growth is primarily triggered by warmer winter and spring air temperatures causing earlier snowmelt that allows the soils to drain and warm quicker. The presented results may help to explain the recently observed 'greening of the Arctic' which may further accelerate in future years due to both direct and indirect effects of winter warming.

  5. 桦木板材的快速干燥%Rapid Drying of Birch Lumber

    Institute of Scientific and Technical Information of China (English)

    李增超; 邱增处; 杨庆; 雷亚芳

    2001-01-01

    采用阶段连续升温干燥基准,增加热湿处理工艺,用炉气间接加热木材干燥窑对不同厚度桦木锯材进行快速窑干工艺试验,实践证明不但干燥周期缩短30%,且提高了干燥质量,易于操作。%Rapid kiln-drying experiment on birch lumber of kiln in whichphased continuous heating drying schedule and the conditioning technology are adopted.It has been proved in practice that such kiln-drying technology can not only shorten the drying period by 30% but also improve drying quality as well as be operated easily.

  6. Regularizations of the Euler product representation for zeta functions and the Birch--Swinnerton-Dyer conjecture

    CERN Document Server

    Fujimoto, Minoru

    2007-01-01

    We consider a variant expression to regularize the Euler product representation of the zeta functions, where we mainly apply to that of the Riemann zeta function in this paper. The regularization itself is identical to that of the zeta function of the summation expression, but the non-use of the M\\"oebius function enable us to confirm a finite behavior of residual terms which means an absence of zeros except for the critical line. Same technique can be applied to the $L$-function associated to the elliptic curve, and we can deal with the Taylor expansion at the pole in critical strip which is deeply related to the Birch--Swinnerton-Dyer conjecture.

  7. Numerical simulation of birch pollen dispersion with an operational weather forecast system.

    Science.gov (United States)

    Vogel, Heike; Pauling, Andreas; Vogel, Bernhard

    2008-11-01

    We included a parameterisation of the emissions of pollen grains into the comprehensive model system COSMO-ART. In addition, a detailed density distribution of birch trees within Switzerland was derived. Based on these new developments, we carried out numerical simulations of the dispersion of pollen grains for an episode that occurred in April 2006 over Switzerland and the adjacent regions. Since COSMO-ART is based on the operational forecast model of the German Weather Service, we are presenting a feasibility study of daily pollen forecast based on methods which have been developed during the last two decades for the treatment of anthropogenic aerosol. A comparison of the model results and very detailed pollen counts documents the current possibilities and the shortcomings of the method and gives hints for necessary improvements.

  8. Ligand binding modulates the structural dynamics and compactness of the major birch pollen allergen.

    Science.gov (United States)

    Grutsch, Sarina; Fuchs, Julian E; Freier, Regina; Kofler, Stefan; Bibi, Marium; Asam, Claudia; Wallner, Michael; Ferreira, Fátima; Brandstetter, Hans; Liedl, Klaus R; Tollinger, Martin

    2014-12-16

    Pathogenesis-related plant proteins of class-10 (PR-10) are essential for storage and transport of small molecules. A prominent member of the PR-10 family, the major birch pollen allergen Bet v 1, is the main cause of spring pollinosis in the temperate climate zone of the northern hemisphere. Bet v 1 binds various ligand molecules to its internal cavity, and immunologic effects of the presence of ligand have been discussed. However, the mechanism of binding has remained elusive. In this study, we show that in solution Bet v 1.0101 is conformationally heterogeneous and cannot be represented by a single structure. NMR relaxation data suggest that structural dynamics are fundamental for ligand access to the protein interior. Complex formation then leads to significant rigidification of the protein along with a compaction of its 3D structure. The data presented herein provide a structural basis for understanding the immunogenic and allergenic potential of ligand binding to Bet v 1 allergens.

  9. Intrinsically microporous polyesters from betulin - toward renewable materials for gas separation made from birch bark.

    Science.gov (United States)

    Jeromenok, Jekaterina; Böhlmann, Winfried; Antonietti, Markus; Weber, Jens

    2011-11-15

    Betulin, an abundant triterpene, can be extracted from birch bark and can be used as a renewable monomer in the synthesis of microporous polyesters. Cross-linked networks and hyperbranched polymers are accessible by an A(2) + B(3) reaction, with betulin being the A(2) monomer and B(3) being a trifunctional acid chloride. Reaction of betulin with a diacid dichloride results in linear, soluble polyesters. The present communication proves that the polyreaction follows the classic schemes of polycondensation reactions. The resulting polymers are analyzed with regard to their micro-porosity by gas sorption, NMR spectroscopy, and X-ray scattering methods. The polymers feature intrinsic microporosity, having ultrasmall pores, which makes them candidates for gas separation membranes, e.g., for the separation of CO(2) from N(2) .

  10. Effects of carbon dioxide concentration and nutrition on photosynthetic functions of white birch seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S. [Lakehead Univ., Thunder Bay, ON (Canada). Faculty of Forestry and the Forest Environment; Dang, Q.L. [Lakehead Univ., Thunder Bay, ON (Canada). Faculty of Forest and the Forest Environment; Chinese Academy of Sciences, Beijing (China). Inst. of Botany, Laboratory of Quantitative Vegetation Ecology

    2006-11-15

    Increases in atmospheric carbon dioxide (CO{sub 2}) can impact photosynthesis and dry mass production of plants. This study investigated the physiological responses of white birch seedlings to elevated carbon dioxide (CO{sub 2}) at low and high supplies of nitrogen (N), phosphorus (P) and potassium (K). A 2-way factorial experiment was carried out with birch seedlings grown for 4 months in environment-controlled greenhouses. Elevated CO{sub 2} enhanced maximal carboxylation rate and photosynthetically active radiation-saturated electron transport rates were measured after 2.5 and 3.5 months of treatment, as well as actual photochemical efficiency and photosynthetic linear electron transport to carboxylation. Net photosynthetic rate increases were observed as well as increases in photosynthetic water use efficiency (WUE); photosynthetic N efficiency and P efficiency. Stomatal conductance, transpiration rate and the fraction of total photosynthetic linear electron transport partitioned to oxygenation were reduced. Low nutrient availability decreased net photosynthetic rates, WUE, and triose phosphate utilization. However, photosynthetic linear electron transport and N use efficiency increased. There were significant interactive effects of CO{sub 2} and nutrition over time, with evidence of photosynthetic up-regulation in response to elevated CO{sub 2} in seedlings receiving high nutrition. Photosynthetic depression in response to low nutrient availability was attributed to biochemical limitation rather than stomatal limitation. Elevated CO{sub 2} reduced leaf N concentration in seedlings receiving low nutrition, but had no significant effect on leaf P or K concentrations. High nutrient availability generally increased area-based leaf N, P and K concentrations but had negligible effects on K after 2.5 months of treatment. Results suggested that increases in electron partitioning to photorespiration in response to low nutrient availability may be related to

  11. Chemical and physical characterization of emissions from birch wood combustion in a wood stove

    Science.gov (United States)

    Hedberg, Emma; Kristensson, Adam; Ohlsson, Michael; Johansson, Christer; Johansson, Per-Åke; Swietlicki, Erik; Vesely, Vaclav; Wideqvist, Ulla; Westerholm, Roger

    The purpose of this study was to characterize the emissions of a large number of chemical compounds emitted from birch wood combustion in a wood stove. Birch wood is widely used as fuel in Swedish household appliances. The fuel load was held constant during six experiments. Particles dust, range 30-330 for the former and 0.8±0.15 for the latter. The source profile of common elements emitted from wood burning differed from that found on particles at a street-level site or in long-distance transported particles. The ratio toluene/benzene in this study was found to be in the range 0.2-0.7, which is much lower than the ratio 3.6±0.5 in traffic exhaust emissions. Formaldehyde and acetone were the most abundant compounds among the volatile ketones and aldehydes. The emission factor varied between 180-710 mg/kg wood for formaldehyde and 5-1300 mg/kg wood for acetone. Of the organic acids analyzed (3,4,5)-trimethoxy benzoic acid was the most abundant compound. Of the PAHs reported, fluorene, phenanthrene, anthracene, fluoranthene and pyrene contribute to more than 70% of the mass of PAH. Of the elements analyzed, K and Si were the most abundant elements, having emission factors of 27 and 9 mg/kg wood, respectively. Although fluoranthene has a toxic equivalence factor of 5% of benzo(a)pyrene (B(a)P), it can be seen that the toxic potency of fluoranthene in wood burning emissions is of the same size as B(a)P. This indicates that the relative carcinogenic potency contribution of fluoranthene in wood smoke would be about 40% of B(a)P.

  12. Winter warming as an important co-driver for Betula nana growth in western Greenland during the past century

    DEFF Research Database (Denmark)

    Hollesen, Jorgen; Buchwal, Agata; Rachlewicz, Grzegorz;

    2015-01-01

    Growing season conditions are widely recognized as the main driver for tundra shrub radial growth, but the effects of winter warming and snow remain an open question. Here, we present a more than 100years long Betulanana ring-width chronology from Disko Island in western Greenland that demonstrates...... a highly significant and positive growth response to both summer and winter air temperatures during the past century. The importance of winter temperatures for Betulanana growth is especially pronounced during the periods from 1910-1930 to 1990-2011 that were dominated by significant winter warming...... of thawing and growing degree-days as well as to winter and spring soil temperatures. In addition to these direct effects, a strong negative growth response to sea ice extent was identified, indicating a possible link between local sea ice conditions, local climate variations and Betula nana growth rates...

  13. Introduction to Distribution and Ecology of Sterile Conks of Inonotus obliquus.

    Science.gov (United States)

    Lee, Min-Woong; Hur, Hyeon; Chang, Kwang-Choon; Lee, Tae-Soo; Ka, Kang-Hyeon; Jankovsky, L

    2008-12-01

    Inonotus obliquus is a fungus that causes white heart rot on several broad-leaved species. This fungus forms typical charcoal-black, sterile conks (chaga) or cinder conks on infected stems of the birche (Betula spp). The dark brown pulp of the sterile conk is formed by a pure mycelial mass of fungus. Chaga are a folk remedy in Russia, reflecting the circumboreal distribution of I. obliquus in boreal forest ecosystems on Betula spp. and in meridional mountain forests on beech (Fagus spp.) in Russia, Scandinavia, Central Europe, and Eastern Europe. Distribution at lower latitudes in Western and Southern Europe, Northern America, Asia, Japan, and Korea is rare. Infected trees grow for many years without several symptoms of decline. The infection can penetrate through stem injuries with exterior sterile conks developing later. In the Czech Republic, cinder conk is found on birches inhabiting peat bogs and in mountain areas with a colder and more humid climate, although it is widespread in other broad leaved species over the Czech Republic. The most common hosts are B. pendula, B. pubescens, B. carpatica, and F. sylvatica. Less frequent hosts include Acer campestre, Acer pseudoplatanus, Alnus glutinosa, Alnus incana, Fraxinus excelsior, Quercus cerris, Q. petraea, Q. robur, Q. delachampii, and Ulmus sp.

  14. Short communication. A review on the efficacy tests and risk analyses conducted on Chondrostereum purpureum, a potential biocontrol agent, in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Hantula, J.; Hamberg, L.; Vartiamaki, H.; Korhonen, K.; Uotila, A.

    2012-11-01

    Hardwood sprouting is a problem in forest regeneration areas, under electric lines, on roadsides and railways. In Finland, isolates of Chondrostereum purpureum were screened by field experiments for their efficiency to control sprouting. The proportion of dead stumps with the best isolates exceeded 80% on birch (Betula pendula and B. pubescens), and C. purpureum was also found to affect the sprouting of aspen (Populus tremula) and rowan (Sorbus aucuparia). The risks of C. purpureum based biocontrol were evaluated by population genetic analysis. It showed that C. purpureum is a geographically undifferentiated species that does not reproduce clonally. The risk of infection of non-target trees was found to be highest in early spring. These findings suggest that the risks of using C. purpureum in biocontrol are small. (Author) 36 refs.

  15. PURIFICATION OF HARDWOOD-DERIVED AUTOHYDROLYSATES

    Directory of Open Access Journals (Sweden)

    Joni Tapani Lehto,

    2012-02-01

    Full Text Available Carbohydrate-containing hydrolysates (1.1 to 14.9% of wood dry matter obtained from autohydrolysis (at 130 to 150°C for 30 to 120 minutes of birch (Betula pendula chips prior to pulping were purified with respect to non-carbohydrate materials, without carbohydrate losses, either by ethyl acetate extraction or XAD-4 resin treatment. In the former case, about 50% of lignin and practically all the furanoic compounds (2-furaldehyde and 5-(hydroxymethylfurfural could be removed, whereas in the latter case, the corresponding amounts were about 30% and 50 to 90%, respectively. A partial recovery of various unsaturated impurities is of importance, because they may act as inhibitors when biochemically converting carbohydrates in hydrolysates into value-added products.

  16. Prevention of birch pollen-related food allergy by mucosal treatment with multi-allergen-chimers in mice.

    Directory of Open Access Journals (Sweden)

    Elisabeth Hoflehner

    Full Text Available BACKGROUND: Among birch pollen allergic patients up to 70% develop allergic reactions to Bet v 1-homologue food allergens such as Api g 1 (celery or Dau c 1 (carrot, termed as birch pollen-related food allergy. In most cases, specific immunotherapy with birch pollen extracts does not reduce allergic symptoms to the homologue food allergens. We therefore genetically engineered a multi-allergen chimer and tested if mucosal treatment with this construct could represent a novel approach for prevention of birch pollen-related food allergy. METHODOLOGY: BALB/c mice were poly-sensitized with a mixture of Bet v 1, Api g 1 and Dau c 1 followed by a sublingual challenge with carrot, celery and birch pollen extracts. For prevention of allergy sensitization an allergen chimer composed of immunodominant T cell epitopes of Api g 1 and Dau c 1 linked to the whole Bet v 1 allergen, was intranasally applied prior to sensitization. RESULTS: Intranasal pretreatment with the allergen chimer led to significantly decreased antigen-specific IgE-dependent β-hexosaminidase release, but enhanced allergen-specific IgG2a and IgA antibodies. Accordingly, IL-4 levels in spleen cell cultures and IL-5 levels in restimulated spleen and cervical lymph node cell cultures were markedly reduced, while IFN-γ levels were increased. Immunomodulation was associated with increased IL-10, TGF-β and Foxp3 mRNA levels in NALT and Foxp3 in oral mucosal tissues. Treatment with anti-TGF-β, anti-IL10R or anti-CD25 antibodies abrogated the suppression of allergic responses induced by the chimer. CONCLUSION: Our results indicate that mucosal application of the allergen chimer led to decreased Th2 immune responses against Bet v 1 and its homologue food allergens Api g 1 and Dau c 1 by regulatory and Th1-biased immune responses. These data suggest that mucosal treatment with a multi-allergen vaccine could be a promising treatment strategy to prevent birch pollen-related food allergy.

  17. Contribution of soil fauna to the mass loss of Betula albosinensis leaf litter at early decomposition stage of subalpine forest litter in western Sichuan%川西亚高山森林凋落物分解初期土壤动物对红桦凋落叶质量损失的贡献

    Institute of Scientific and Technical Information of China (English)

    夏磊; 吴福忠; 杨万勤; 谭波

    2012-01-01

    2010年10月26日-2011年4月18日在川西亚高山地区季节性冻融期间,选择典型的红桦-岷江冷杉林,采用凋落物分解袋法调查了不同网孔(0.02、0.125、1和3 mm)凋落物分解袋内的凋落物质量损失,分析微型、中型和大型土壤动物对红桦凋落叶分解的贡献.结果表明:在季节性冻融期间,0.02、0.125、1和3 mm分解袋内的红桦凋落叶质量损失率分别为11.8%、13.2%、15.4%和19.5%,不同体径土壤动物对红桦凋落叶质量损失的贡献率为39.5%;不同孔径凋落物袋内土壤动物的类群和个体相对密度与凋落叶的质量损失率的变化趋势相对一致.在季节性冻融的初期、深冻期和融化期,不同土壤动物对红桦凋落叶质量损失的贡献率为大型土壤动物(22.7%)>中型土壤动物(11.9%)>微型土壤动物(7.9%).季节性冻融期间土壤动物活动是影响川西亚高山森林凋落物分解的重要因素之一.%In order to quantify the contribution of soil fauna to the decomposition of birch (Betula albosinensis) leaf litter in subalpine forests in western Sichuan of Southwest China during freeze-thaw season, a field experiment with different mesh sizes (0.02, 0.125 , 1 and 3 mm) of litterbags was conducted in a representative birch-fir (Abies faxoniana) forest to investigate the mass loss rate of the birch leaf litter from 26 October, 2010 to 18 April, 2011, and the contributions of micro-, meso- and macro-fauna to the decomposition of the leaf litter. Over the freeze-thaw season, 11. 8% , 13. 2% , 15. 4% and 19. 5% of the mass loss were detected in the litterbags with 0. 02, 0. 125, 1 and 3 mm mesh sizes, respectively. The total contribution of soil fauna to the litter decomposition accounted for 39.5% of the mass loss, and the taxa and individual relative density of the soil fauna in the litterbags had the similar variation trend with that of the mass loss rate. The contribution rate of soil fauna to the

  18. Assessment of suitability of tree species for the production of biomass on trace element contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Evangelou, Michael W.H., E-mail: michael.evangelou@env.ethz.ch [Institute of Terrestrial Ecosystems, ETH Zuerich, Universitaetstrasse 16, CH-8092 Zuerich (Switzerland); Deram, Annabelle, E-mail: annabelle.deram@univ-lille2.fr [Laboratoire des sciences vegetales et fongiques - EA4483, Faculte des sciences pharmaceutiques et biologiques-ILIS, Universite Lille Nord de France - 3, rue du Professeur Laguesse, B.P. 83, F-59006 Lille Cedex (France); Gogos, Alexander; Studer, Bjoern; Schulin, Rainer [Institute of Terrestrial Ecosystems, ETH Zuerich, Universitaetstrasse 16, CH-8092 Zuerich (Switzerland)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer Birch: lowest metal concentrations in foliage, wood and bark. Black-Right-Pointing-Pointer Bark proportion does not have to decline with increasing age of tree. Black-Right-Pointing-Pointer Long harvest rotation (>25 y) reduces metal concentrations in stem. Black-Right-Pointing-Pointer Birch: most suitable tree for BCL. - Abstract: To alleviate the demand on fertile agricultural land for production of bioenergy, we investigated the possibility of producing biomass for bioenergy on trace element (TE) contaminated land. Soil samples and plant tissues (leaves, wood and bark) of adult willow (Salix sp.), poplar (Populus sp.), and birch (Betula pendula) trees were collected from five contaminated sites in France and Germany and analysed for Zn, Cd, Pb, Cu, Ca, and K. Cadmium concentration in tree leaves were correlated with tree species, whereas Zn concentration in leaves was site correlated. Birch revealed significantly lower leaf Cd concentrations (1.2-8.9 mg kg{sup -1}) than willow and poplar (5-80 mg kg{sup -1}), thus posing the lowest risk for TE contamination of surrounding areas. Birch displayed the lowest bark concentrations for Ca (2300-6200 mg kg{sup -1}) and K (320-1250 mg kg{sup -1}), indicating that it would be the most suitable tree species for fuel production, as high concentrations of K and Ca decrease the ash melting point which results in a reduced plant lifetime. Due to higher TE concentrations in bark compared to wood a small bark proportion in relation to the trunk is desirable. In general the bark proportion was reduced with the tree age. In summary, birch was amongst the investigated species the most suitable for biomass production on TE contaminated land.

  19. Changes in expression of BetV1 allergen of silver birch pollen in urbanized area of Ukraine.

    Science.gov (United States)

    Žiarovská, Jana; Labajová, Mária; Ražná, Katarína; Bežo, Milan; Štefúnová, Veronika; Shevtsova, Tatiana; Garkava, Kateryna; Brindza, Ján

    2013-01-01

    The aim of the study was to determinate the level of expression of silver birch allergen Betv1 in pollen samples from different Ukraine areas by RT-qPCR SYBR Green assay. Protocol for quantifying the expression of Betv1 allergen was developed when testing of three housekeeping genes-cyclophylin, alpha-tubulin and transcription factor CBF1. Samples from urbanized area was analysed by real-time PCR when a sample from forest growth conditions was used as a calibrator. Real-time PCR based quantifying of Betv1 provides a useful method for rapid and sensitive analyses of this silver birch allergen. Our results show higher expression levels in samples from central parts of urbanized area as housing estates when compared to the samples from borders of the urbanized area.

  20. Molecular characterisation of birch bark tar by headspace solid-phase microextraction gas chromatography-mass spectrometry: a new way for identifying archaeological glues.

    Science.gov (United States)

    Regert, M; Alexandre, V; Thomas, N; Lattuati-Derieux, A

    2006-01-06

    To develop an analytical methodology, as non-destructive as possible, suitable for the identification of natural substances from archaeological origin, we studied the potentiality of solid-phase microextraction (SPME) for analysing birch bark tar, an adhesive commonly used during ancient times. First of all, birch bark tars were produced by a controlled heating of birch bark. The two kinds of samples obtained using different processes of fabrication, one at liquid state, the second one at solid state, were then analysed by headspace HS-SPME-GC-MS. Different conditions of sample treatment were tested (two different fibre coatings, various times and temperatures of extraction) in order to suggest optimal conditions for the analysis of birch bark tar. Both samples were shown to be rich in volatile organic components. Two main groups of constituents, namely phenolic compounds issued from lignin or tannin known to be present in bark and sesquiterpenoid hydrocarbons, secondary metabolites largely distributed in the plant kingdom, were detected for the first time in birch bark tar. HS-SPME-GC-MS appears thus to be a very efficient method for investigating the volatiles emitted by plant tars and could be further used for the study of birch bark tar samples issued from archaeological context.

  1. The major birch pollen allergen Bet v 1 induces different responses in dendritic cells of birch pollen allergic and healthy individuals.

    Directory of Open Access Journals (Sweden)

    Ursula Smole

    Full Text Available Dendritic cells play a fundamental role in shaping the immune response to allergens. The events that lead to allergic sensitization or tolerance induction during the interaction of the major birch pollen allergen Bet v 1 and dendritic cells are not very well studied. Here, we analyzed the uptake of Bet v 1 and the cross-reactive celery allergen Api g 1 by immature monocyte-derived dendritic cells (iMoDCs of allergic and normal donors. In addition, we characterized the allergen-triggered intracellular signaling and transcriptional events. Uptake kinetics, competitive binding, and internalization pathways of labeled allergens by iMoDCs were visualized by live-cell imaging. Surface-bound IgE was detected by immunofluorescence microscopy and flow cytometry. Allergen- and IgE-induced gene expression of early growth response genes and Th1 and Th2 related cytokines and chemokines were analyzed by real-time PCR. Phosporylation of signaling kinases was analyzed by Western blot. Internalization of Bet v 1 by iMoDCs of both donor groups, likely by receptor-mediated caveolar endocytosis, followed similar kinetics. Bet v 1 outcompeted Api g 1 in cell surface binding and uptake. MoDCs of allergic and healthy donors displayed surface-bound IgE and showed a pronounced upregulation of Th2 cytokine- and NFκB-dependent genes upon non-specific Fcε receptor cross-linking. In contrast to these IgE-mediated responses, Bet v 1-stimulation increased transcript levels of the Th2 cytokines IL-4 and IL-13 but not of NFκB-related genes in MoDCs of BP allergic donors. Cells of healthy donors were either unresponsive or showed elevated mRNA levels of Th1-promoting chemokines. Moreover, Bet v 1 was able to induce Erk1/2 and p38 MAPK activation in BP allergics but only a slight p38 activation in normal donors. In conclusion, our data indicate that Bet v 1 favors the activation of a Th2 program only in DCs of BP allergic individuals.

  2. Dissolved organic carbon and nitrogen leaching from Scots pine, Norway spruce and silver birch stands in southern Sweden

    OpenAIRE

    Fröberg, Mats; Hansson, Karna; Kleja, Dan Berggren; Alavi, Ghasem

    2011-01-01

    The effects of three common tree species – Scots pine, Norway spruce and silver birch – on leaching of dissolved organic carbon and dissolved nitrogen were studied in an experimental forest with podzolised soils in southern Sweden. We analyzed soil water collected with lysimeters and modeled water fluxes to estimate dissolved C and N fluxes. Specific UV absorbance (SUVA) was analyzed to get information about the quality of dissolved organic matter leached from the different stands. Under the ...

  3. Impact of ectohumus application in birch and pine nurseries on the presence of soil mites (Acari, Oribatida in particular

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    Klimek Andrzej

    2016-03-01

    Full Text Available Intensively used forest nurseries are characterised by degradation processes that lead to a drop in the quality of seedlings. The main reason of this problem is a decrease in biological soil diversity. Therefore, an attempt of nursery soil enrichment by introducing ectohumus – as compost and fresh litter – from the pine forest was carried out. The research was carried out in 2009–2011 in the Bielawy forest nursery near the city of Toruń, Poland. The objective of the study was to determine the impact of organic fertilisation (compost made up of forest humus and mulching using fresh ectohumus on the density and community composition of Acari mites and on species composition of oribatid mites (Oribatida in the nurseries of silver birch and Scots pine. Mites, especially oribatid mites, were treated as bioindicators of soil biological activity. Research has shown that mulching using fresh ectohumus caused a multiple increase in the density of mites, especially in saprophagous mites Oribatida. Oribatid mites were clearly more numerous in birch cultivation than in that of pine. Overall, 27 species of oribatid mites were found. Mulching resulted in a significant growth in species diversity in both cultivations. The most numerous oribatid mite in the area under the study was Oribatula tibialis. This species was present in all plots and showed clear preference for birch cultivation. Tectocepheus velatus and Oppiella nova, common and known to be present in a variety of environments, were slightly less numerous.

  4. Optimization of ultrasonic-assisted extraction (UAE) of betulin from white birch bark using response surface methodology.

    Science.gov (United States)

    Chen, Qi-he; Fu, Ming-liang; Liu, Jin; Zhang, Hai-feng; He, Guo-qing; Ruan, Hui

    2009-06-01

    Betulin is an abundant naturally occurring triterpene, which makes it a potentially important raw material for a precursor of biologically active compounds. The objective of the current study was to determine the optimum UAE conditions for betulin from B. papyfera bark. The optimum conditions were evaluated with fractional factorial design and optimized using response surface methodology. High yields of betulin were observed from white birch bark by UAE technology. The solvent concentration and the ratio of material to solvent were the most significant parameters on betulin extraction as evaluated through FFD. The extraction conditions were further investigated with central composite design. The fitted second-order model revealed that the optimal conditions consisted of 98% ethonal concentration, 1:42 the ratio of white birch bark to solvent, extraction temperature 50 degrees C, ultrasonic frequency 5kHz and extraction time 3h. Under the optimized condition, the maximum productivity of betulin predicted is 23.17%. The extraction productivity and purity of betulin under the optimized extraction conditions were great higher than that of the non-optimized condition. The present study demonstrates that ultrasound is a great efficiency tool for the fast extraction of betulin from white birch bark.

  5. An undergraduate laboratory experiment for measuring ε 0, μ 0 and speed of light c with do-it-yourself catastrophe machines: electrostatic and magnetostatic pendula

    Science.gov (United States)

    Mishonov, Todor M.; Varonov, Albert M.; Maksimovski, Dejan D.; Manolev, Stojan G.; Gourev, Vassil N.; Yordanov, Vasil G.

    2017-03-01

    An experimental set-up for electrostatic measurement of {\\varepsilon }0, separate magnetostatic measurement of {μ }0 and determination of the speed of light c=1/\\sqrt{{\\varepsilon }0{μ }0} according to Maxwell’s theory with percent accuracy is described. No forces are measured with the experimental set-up, therefore there is no need for a scale, and the experiment cost of less than £20 is mainly due to the batteries used. Multiplied 137 times, this experimental set-up was given at the Fourth Open International Experimental Physics Olympiad (EPO4) and a dozen high school students performed successful experiments. The experimental set-up actually contains two different pendula for electric and magnetic measurements. In the magnetic experiment the pendulum is constituted by a magnetic coil attracted to a fixed one. In the electrostatic pendulum when the distance between the plates becomes shorter than a critical value the suspended plate catastrophically sticks to the fixed one, while in the magnetic pendulum the same occurs when the current in the coils becomes greater than a certain critical value. The basic idea of the methodology is to use the loss of stability as a tool for the determination of fundamental constants.

  6. Sphagnum peatlands as a unique habitat for the long-term survival of glacial relicts: a case study of Betula nana

    Science.gov (United States)

    Slowinski, M. M.; Slowinska, S.; Noryśkiewicz, A. M.; Lamentowicz, M.; Kołaczek, P.

    2014-12-01

    Sphagnum peatlands are characterized by distinctive vegetation, hydrology and local climate. They are very important areas for flora and fauna. In the last decade, much effort was made at better understanding of microrefugia and their important role in post-glacial migration of various plant species. The aim of this study is to explain a long-term persistence of the glacial relict Betula nana in a Sphagnum peatland in northern Poland far from the southern range of its natural distribution. We suppose that the persistence of Betula nana is driven by a) the morphology and geology of the catchment, b) the maintenance of open vegetation on the peatland surface and c) exceptional microclimatic and hydrological conditions. A detailed research was carried out on the peat profile using pollen analysis, to reconstruct the presence of open habitat on the mire during the Holocene. Furthermore, detailed monitoring of local climate, hydrology of the peatland and the surrounding area was conducted. The pollen analysis revealed a continuous presence of Betula nana in the postglacial history of the peatland. The results of local climate monitoring indicated that the mire possesses a typical microclimate, with air temperature amplitude much higher in relation to the open area, in particular during the growing season. This, in combination with the hydrology, which depends on the geology of the surrounding area, affects Betula nana population. Linje mire is a unique microrefugium sustained by local factors such as microclimate, geology, local relief and hydrology. However, it is still challenging to explain the intriguing case why this species still occurs within the study site. This work was funded by the National Science Centre grant NN306060940 and Polish-Swiss Research Programme PSPB-013/2010. This study is a contribution to the Virtual Institute of Integrated Climate and Landscape Evolution (ICLEA) of the Helmholtz Association.

  7. Prediction of the birch pollen season characteristics in Cracow, Poland using an 18-year data series.

    Science.gov (United States)

    Dorota, Myszkowska

    2013-03-01

    The aim of the study was to construct the model forecasting the birch pollen season characteristics in Cracow on the basis of an 18-year data series. The study was performed using the volumetric method (Lanzoni/Burkard trap). The 98/95 % method was used to calculate the pollen season. The Spearman's correlation test was applied to find the relationship between the meteorological parameters and pollen season characteristics. To construct the predictive model, the backward stepwise multiple regression analysis was used including the multi-collinearity of variables. The predictive models best fitted the pollen season start and end, especially models containing two independent variables. The peak concentration value was predicted with the higher prediction error. Also the accuracy of the models predicting the pollen season characteristics in 2009 was higher in comparison with 2010. Both, the multi-variable model and one-variable model for the beginning of the pollen season included air temperature during the last 10 days of February, while the multi-variable model also included humidity at the beginning of April. The models forecasting the end of the pollen season were based on temperature in March-April, while the peak day was predicted using the temperature during the last 10 days of March.

  8. Detection of Malware and Malicious Executables Using E-Birch Algorithm

    Directory of Open Access Journals (Sweden)

    Dr. Ashit Kumar Dutta

    2016-01-01

    Full Text Available Malware detection is one of the challenges to the modern computing world. Web mining is the subset of data mining used to provide solutions for complex problems. Web intelligence is the new hope for the field of computer science to bring solution for the malware detection. Web mining is the method of web intelligence to make web as an intelligent tool to combat malware and phishing websites. Generally, malware injected through websites into the user system and modifies the executable file and paralyze the whole activity of the system. Antivirus application utilizes the data mining technique to find the malware in the web. There is a need of heuristic approach to solve the malware problem. Dynamic analysis methods yield better result than the static methods. Data mining is the best option for the dynamic analysis of malware or malicious program. The purpose of the research is to apply the enhanced Birch algorithm to find the malware and modified executables of Windows and Android operating system.

  9. Analysis of Individual Tree Competition Effect on Diameter Growth of Silver Birch in Estonia

    Directory of Open Access Journals (Sweden)

    Kobra Maleki

    2015-08-01

    Full Text Available Aim of study: The present study evaluates a set of competition indices including spatially explicit indices combined with different competitor selection approaches and non-spatially explicit competition indices. The aim was to quantify and describe the neighbouring effects on the tree diameter growth of silver birch trees. Area of study: Region throughout Estonia. Material and methods: Data from the Estonian Network of Forest Research Plots was used. After quantifying the selected indices, the best non-spatial indices and spatial indices (combined with neighbour selection methods were separately devised into a growth model as a predictor variable to assess the ability of the diameter growth model before and after adding competition measures. To test the species-specific effect on the competition level, the superior indices were recalculated using Ellenberg’s light indicators and incorporated into the diameter growth model. Main results: Statistical analyses showed that the diameter growth is a function of neighbourhood interactions and spatial indices were better growth predictors than non-spatial indices. In addition, the best selections of competitive neighbours were acquired based on the influence zone and the competition elimination angle concepts, and using Ellenberg’s light values had no significant improvement in quantifying the competition effects. Research highlights: Although the best ranking spatial competition measures were superior to the best non-spatial indices, the differences were negligible.

  10. Methane consumption and soil respiration by a birch forest soil in West Siberia

    Science.gov (United States)

    Nakano, Tomoko; Inoue, Gen; Fukuda, Masami

    2004-07-01

    Methane and carbon dioxide fluxes were measured in a birch forest soil in West Siberia, in August 1999, June 2000 and September 2000. The study site had a very thick organic horizon that was subject to drought during the observation periods. The soils always took up CH4, while CO2 was released from the surface to the atmosphere. CH4 consumption and CO2 emission rates ranged from 0.092 to 0.28 mg C m2 h1 and from 110 to 400 mg C m2 h1 respectively. The CH4 consumption rate and soil temperatures showed significant relationships for individual measurements. The soil respiration rate was weakly correlated with individual soil temperatures. This study examined the effect of current and lagged soil temperatures at a depth of 5 cm on CH4 consumption and soil respiration. The variation in the correlation coefficient between CH4 consumption and lagged soil temperature was greatest at a 4-h lag, whereas that for soil respiration showed a gentle peak at lags from several hours to half a day. This difference in the temperature-related lag effect between CH4 consumption and soil respiration results from differences in the exchange processes. Neither flux showed any correlation with soil moisture. The limited variation in soil moisture during our observation period may account for the lack of correlation. However, the droughty soil conditions resulted in high gas diffusion and, consequently, high CH4 consumption.

  11. Ligand Binding Modulates the Structural Dynamics and Compactness of the Major Birch Pollen Allergen

    Science.gov (United States)

    Grutsch, Sarina; Fuchs, Julian E.; Freier, Regina; Kofler, Stefan; Bibi, Marium; Asam, Claudia; Wallner, Michael; Ferreira, Fátima; Brandstetter, Hans; Liedl, Klaus R.; Tollinger, Martin

    2014-01-01

    Pathogenesis-related plant proteins of class-10 (PR-10) are essential for storage and transport of small molecules. A prominent member of the PR-10 family, the major birch pollen allergen Bet v 1, is the main cause of spring pollinosis in the temperate climate zone of the northern hemisphere. Bet v 1 binds various ligand molecules to its internal cavity, and immunologic effects of the presence of ligand have been discussed. However, the mechanism of binding has remained elusive. In this study, we show that in solution Bet v 1.0101 is conformationally heterogeneous and cannot be represented by a single structure. NMR relaxation data suggest that structural dynamics are fundamental for ligand access to the protein interior. Complex formation then leads to significant rigidification of the protein along with a compaction of its 3D structure. The data presented herein provide a structural basis for understanding the immunogenic and allergenic potential of ligand binding to Bet v 1 allergens. PMID:25517162

  12. The influence of recombinant production on the immunologic behavior of birch pollen isoallergens.

    Directory of Open Access Journals (Sweden)

    Michael Wallner

    Full Text Available BACKGROUND: Allergic reactions towards the birch major pollen allergen Bet v 1 are among the most common causes of spring pollinosis in the temperate climate zone of the Northern hemisphere. Natural Bet v 1 is composed of a complex mixture of different isoforms. Detailed analysis of recombinant Bet v 1 isoforms revealed striking differences in immunologic as well as allergenic properties of the molecules, leading to a classification of Bet v 1 isoforms into high, medium, and low IgE binding proteins. Especially low IgE binding Bet v 1 isoforms have been described as ideal candidates for desensitizing allergic patients with allergen specific immunotherapy (SIT. Since diagnosis and therapy of allergic diseases are highly dependent on recombinant proteins, continuous improvement of protein production is an absolute necessity. METHODOLOGY: Therefore, two different methods for recombinant production of a low IgE binding Bet v 1 isoform were applied; one based on published protocols, the other by implementing latest innovations in protein production. Both batches of Bet v 1.0401 were extensively characterized by an array of physicochemical as well as immunological methods to compare protein primary structure, purity, quantity, folding, aggregation state, thermal stability, and antibody binding capacity. CONCLUSION: The experiments demonstrated that IgE antibody binding properties of recombinant isoallergens can be significantly influenced by the production method directly affecting possible clinical applications of the molecules.

  13. Ground bryophyte diversity in secondary birch forests in western Sichuan, China%亚高山次生桦木林地表苔藓组成与多样性

    Institute of Scientific and Technical Information of China (English)

    闫晓丽; 包维楷

    2011-01-01

    桦木林(Betula spp.)是我国原始冷杉林(Abies spp.)皆伐后自然恢复形成的主要次生林之一,为揭示其发育过程中地表苔藓组成与多样性差异,评估其自然恢复状况,我们选择了四川省金川县507林场地形条件基本一致的3个桦木林地以及1个原始岷江冷杉(Abies faxoniana)林地,调查了地表苔藓层结构和物种组成.结果显示:(1)桦木林的地表苔藓植物盖度低于原始林,不同年龄的桦木林之间其盖度没有差异(P>0.05),但优势种的组成差异及物种替代明显;(2)桦木林地表苔藓物种丰富度较原始林高,不同年龄相比,9年生和22年生较42年生桦木林地表苔藓种类丰富;(3)未郁闭桦木林(9年生)与郁闭林(22年生和42年生)间的地表苔藓物种组成相似程度(相似性系数为0.24-0.29)低于它与原始林间的相似程度(0.51);22年生和42年生桦木林间地表苔藓物种组成相似程度(相似性系数为0.50)高于它们与原始林间的相似性程度(0.13-0.24),在自然恢复过程中,桦木林与原始林下地表苔藓共有种数量逐渐减少,相似程度降低.原始林下35种地表苔藓植物中只有25种存在于迹地桦木林地.上述分析表明:迹地上自然恢复9-42年的桦木林下地表苔藓多样性虽然较云杉人工林高,但仅保存约70%的原始林下种类,而约有29%的敏感苔藓种类无法通过次生林自然恢复过程得以保育或恢复.%Secondary birch (Betula spp.) forest is an important vegetation type in western Sichuan, China.These forests have naturally regenerated from primary fir (Abies spp.) forests after clear-cutting. However,little is known about ground bryophyte species composition and community structure during this succession sequence. In our study, we sampled three plots in 9-, 22-, and 42-year old secondary forests, and a primary fir forest, respectively, in Jinchuan County. We found that bryophyte coverage in different aged secondary forests was

  14. Thermal Insulation from Hardwood Residues

    Science.gov (United States)

    Sable, I.; Grinfelds, U.; Vikele, L.; Rozenberga, L.; Zeps, M.; Luguza, S.

    2015-11-01

    Adequate heat is one of the prerequisites for human wellbeing; therefore, building insulation is required in places where the outside temperature is not suitable for living. The climate change, with its rising temperatures and longer dry periods, promotes enlargement of the regions with conditions more convenient for hardwood species than for softwood species. Birch (Betula pendula) is the most common hardwood species in Latvia. The aim of this work was to obtain birch fibres from wood residues of plywood production and to form low-density thermal insulation boards. Board formation and production was done in the presence of water; natural binder, fire retardant and fungicide were added in different concentrations. Board properties such as density, transportability or resistance to particulate loss, thermal conductivity and reaction to fire were investigated. This study included thermal insulation boards with the density of 102-120 kg/m3; a strong correlation between density and the binder amount was found. Transportability also improved with the addition of a binder, and 0.1-0.5% of the binder was the most appropriate amount for this purpose. The measured thermal conductivity was in the range of 0.040-0.043 W/(m·K). Fire resistance increased with adding the fire retardant. We concluded that birch fibres are applicable for thermal insulation board production, and it is possible to diversify board properties, changing the amount of different additives.

  15. Photosynthetic limitation of several representative subalpine species in the Catalan Pyrenees in summer.

    Science.gov (United States)

    Fernàndez-Martínez, J; Fleck, I

    2016-07-01

    Information on the photosynthetic process and its limitations is essential in order to predict both the capacity of species to adapt to conditions associated with climate change and the likely changes in plant communities. Considering that high-mountain species are especially sensitive, three species representative of subalpine forests of the Central Catalan Pyrenees: mountain pine (Pinus uncinata Mill.), birch (Betula pendula Roth) and rhododendron (Rhododendron ferrugineum L.) were studied under conditions associated with climate change, such as low precipitation, elevated atmospheric [CO2 ] and high solar irradiation incident at Earth's surface, in order to detect any photosynthetic limitations. Short-term high [CO2 ] increased photosynthesis rates (A) and water use efficiency (WUE), especially in birch and mountain pine, whereas stomatal conductance (gs ) was not altered in either species. Birch showed photosynthesis limitation through stomatal closure related to low rainfall, which induced photoinhibition and early foliar senescence. Rhododendron was especially affected by high irradiance, showing early photosynthetic saturation in low light, highest chlorophyll content, lowest gas exchange rates and least photoprotection. Mountain pine had the highest A, photosynthetic capacity (Amax ) and light-saturated rates of net CO2 assimilation (Asat ), which were maintained under reduced precipitation. Furthermore, maximum quantum yield (Fv /Fm ), thermal energy dissipation, PRI and SIPI radiometric index, and ascorbate content indicated improved photoprotection with respect to the other two species. However, maximum velocity of carboxylation of RuBisco (Vcmax ) indicated that N availability would be the main photosynthetic limitation in this species.

  16. Effects of reindeer on the re-establishment of Betula pubescens subsp. czerepanovii and Salix phylicifolia in a subarctic meadow

    Directory of Open Access Journals (Sweden)

    Michael den Herder

    2003-04-01

    Full Text Available The effect of reindeer browsing on the regeneration of Betula pubescens subsp. czerepanovii and Salix phylicifolia was studied in a subarctic meadow in Finnish Lapland. The aim of the study was to see whether tree recovery from seeds is possible under heavy reindeer-browsing pressure. After removal of the ground and field layer vegetation in 1986, two exclosures were established so that the effect of reindeer on the secondary succession, starting from seeds, could be studied. The size and the number of B. pubescens and S. phylicifolia were recorded in 1994, 1996, 1997 and 1999. Reindeer significantly reduced the height and the number of saplings (plants > 10 cm high of B. pubescens and S. phylicifolia but the number of seedlings (plants < 10 cm high did not differ between browsed and unbrowsed plots. Furthermore the heightclass distribution of saplings was different inside the exlosures compared to control areas. Over time browsed plots continued to have high densities of small saplings while in protected plots an increasing number of larger saplings appeared. In our study site, regeneration from seeds seemed possible although the height of B. pubescens and S. phylicifolia was limited by reindeer. 

  17. [Species composition and point pattern analysis of standing trees in secondary Betula albosinensis forest in Xiaolongshan of west Qinling Mountains].

    Science.gov (United States)

    Guo, Yao-xin; Kang, Bing; Li, Gang; Wang, De-xiang; Yang, Gai-he; Wang, Da-wei

    2011-10-01

    An investigation was conducted on the species composition and population diameter-class structure of a typical secondary Betula albo-sinensis forest in Xiaolongshan of west Qinling Mountains, and the spatial distribution pattern and interspecific correlations of the main populations were analyzed at multiple scales by the O-ring functions of single variable and double variables. In the test forest, B. albo-sinensis was obviously dominant, but from the analysis of DBH class distribution, the B. albo-sinensis seedlings were short of, and the natural regeneration was very poor. O the contrary, the regeneration of Abies fargesii and Populus davidianas was fine. B. albo-sinensis and Salix matsudana had a random distribution at almost all scales, while A. fargesii and P. davidianas were significantly clumped at small scale. B. albo-sinensis had positive correlations with A. fargesii and P. davidianas at medium scale, whereas S. matsudana had negative correlations with B. albo-sinensis, A. fargesii, and P. davidianas at small scale. No significant correlations were observed between other species. The findings suggested that the spatial distribution patterns of the tree species depended on their biological characteristics at small scale, but on the environmental heterogeneity at larger scales. In a period of future time, B. albo-sinensis would still be dominant, but from a long-term view, it was necessary to take some artificial measures to improve the regeneratio of B. albo-sinensis.

  18. [Effects of elevated CO2 concentration and temperature on nutrient accumulation and allocation in Betula albo-sinensis seedlings].

    Science.gov (United States)

    Hou, Ying; Wang, Kai-yun; Zhang, Chao

    2008-01-01

    With enclosed chamber system, this paper studied the effects of elevated CO2 concentration (ambient + 350 micromol x mol(-1), E(C)), temperature (ambient + 2 degrees C, E(T)), and their combination (E(CT)) on the nutrient accumulation and allocation in subalpine Betula albo-sinensis seedlings in western Sichuan Province. The results showed that after a growth season, the accumulation amount of N, P and K per plant increased by 44%, 45% and 11% under E(C) (P allocation to leaves reduced by 11.68% (P 0.05), but decreased by 0.69%, 10.35% and 0.05% under E(T) (P > 0.05), respectively. The N allocation pattern under E(CT) was similar to that under E(C). The allocation of P and K had greater differences under E(C), E(T) and E(CT). All of these suggested that elevated CO2 concentration and temperature could promote nutrient accumulation, and change its allocation pattern in plant organs.

  19. Fluorescence parameters of leaves of trees and shrubs during period of adverse weather conditions in Krasnoyarsk

    Science.gov (United States)

    Zavorueva, E. N.; Zavoruev, V. V.

    2015-11-01

    The effect of adverse weather conditions (AWC) on the fluorescence parameters of leaves Prinsepia sinensis, Amelanchier florida, Crataegus chlorocarca is obtained. However, significant changes in the fluorescence of the leaves of Acer negundo, Betula pendula under AWC were not observed.

  20. Climate warming feedback from mountain birch forest expansion: reduced albedo dominates carbon uptake.

    Science.gov (United States)

    de Wit, Heleen A; Bryn, Anders; Hofgaard, Annika; Karstensen, Jonas; Kvalevåg, Maria M; Peters, Glen P

    2014-07-01

    Expanding high-elevation and high-latitude forest has contrasting climate feedbacks through carbon sequestration (cooling) and reduced surface reflectance (warming), which are yet poorly quantified. Here, we present an empirically based projection of mountain birch forest expansion in south-central Norway under climate change and absence of land use. Climate effects of carbon sequestration and albedo change are compared using four emission metrics. Forest expansion was modeled for a projected 2.6 °C increase in summer temperature in 2100, with associated reduced snow cover. We find that the current (year 2000) forest line of the region is circa 100 m lower than its climatic potential due to land-use history. In the future scenarios, forest cover increased from 12% to 27% between 2000 and 2100, resulting in a 59% increase in biomass carbon storage and an albedo change from 0.46 to 0.30. Forest expansion in 2100 was behind its climatic potential, forest migration rates being the primary limiting factor. In 2100, the warming caused by lower albedo from expanding forest was 10 to 17 times stronger than the cooling effect from carbon sequestration for all emission metrics considered. Reduced snow cover further exacerbated the net warming feedback. The warming effect is considerably stronger than previously reported for boreal forest cover, because of the typically low biomass density in mountain forests and the large changes in albedo of snow-covered tundra areas. The positive climate feedback of high-latitude and high-elevation expanding forests with seasonal snow cover exceeds those of afforestation at lower elevation, and calls for further attention of both modelers and empiricists. The inclusion and upscaling of these climate feedbacks from mountain forests into global models is warranted to assess the potential global impacts.

  1. 华北落叶松-白桦凋落物混合分解研究%Mixed litter decomposition of Larix principis-rupprechtii and Betula platyphylla

    Institute of Scientific and Technical Information of China (English)

    赵喆; 刘延文; 纪福利; 刘晓兰; 贾忠奎; 马履一

    2016-01-01

    采用凋落物袋法对华北落叶松 Larix gmelinii 和白桦 Betula platyphylla 叶凋落物以不同比例混合(PB、PL、8L:2B、7L:3B、6L:4B、5L:5B),研究凋落物混合分解的分解速率及养分动态变化。结果表明:不同比例华北落叶松—白桦凋落物混合分解均表现出了前期分解迅速,后期分解缓慢的特点。单独分解时,纯白桦的分解速率要高于纯华北落叶松的分解速率,混合凋落物对凋落物的分解有不同程度的促进作用,6L:4B 的凋落物残留量最小,分解最快。在分解前期,混合凋落物对分解速率并没有显著影响,但对分解过程中的养分动态有显著混合效应。混合分解促进了华北落叶松凋落物中 N、P 的富集,且随着白桦比例的增加凋落物中 N、P 的富集加剧,混合处理的 N、P 含量均高于纯华北落叶松处理,在分解后期,部分处理(6L:4B、5L:5B)N、P 含量甚至超过纯白桦。混合分解对 K 的释放无显著影响。混合分解降低了华北落叶松凋落物的 C/N 和 C/P。%Research the mixed litter decomposition rate and nutrient dynamic change of Larix principis-rupprechtii and Betula platyphylla leaf litter with different mixing ratio (PB、PL、8L:2B、7L:3B、6L:4B、5L:5B). This reserch use the litter bag method. Important findings: (1) Different proportion of Larix principis-rupprechtii and Betula platyphylla mixed litter showed early decompose rapidly, slow decomposition characteristics late. (2) Decomposition rate of pure Betula platyphylla was higher than that of pure Larix principis-rupprechtii when separate decomposition, mixed treatment on litter decomposition have different degrees of promoting function, 6L:4B had the highest decomposition rate. (3) Mixed litter decomposition had significant effect on nutrient dynamic in the process of decomposition. It promoted the enrichment of Larix principis-rupprechtii litter of N element

  2. Large-scale climate variability and its effects on mean temperature and flowering time of Prunus and Betula in Denmark

    Science.gov (United States)

    Gormsen, A. K.; Hense, A.; Toldam-Andersen, T. B.; Braun, P.

    2005-08-01

    Large-scale climate variability largely affects average climatic conditions and therefore is likely to influence the phenology of plants. In NW-Europe, the North Atlantic Oscillation (NAO) particularly influences winter climate and, through climate interactions on plants, flowering time of all tree species. In Denmark, like in many other NW-European countries, flowering of most tree species has become earlier since the end of the 1980’s. To quantify a possible relation between NAO and flowering time of tree species, two sources of phenological information from the Copenhagen area (Denmark) were analysed, i.e. pollen counts of the genus Betula and observed first bloom dates of Prunus avium. The Winter NAO explained 29 and 37% of the variation of monthly mean temperature for February and March, respectively. The influence of temperature on flowering time was up to 56% to 60% for the February April mean. A direct correlation of Winter NAO-index and flowering time also revealed a clear relation but the time of influence was earlier (December to February). This was shown to be the likely result of a combination of direct and time-lagged effects of the NAO on air and sea surface temperature. The NAO signal is apparently stored in the North Sea and then influences temperature east up to the Baltic States. It is shown that Denmark is right in the centre of direct and time-lagged effects of the NAO. This offers the possibility of using the NAO-index for predicting flowering time of Prunus avium. The beginning of pollen flow appears to be influenced too much by short-term perturbations of the climate system decreasing the value of the NAO-index for prediction. However, it indicates a close relationship between natural climate variability, measured by the NAO index, and flowering time of tree species for Denmark.

  3. Abundance and Relative Distribution of Frankia Host Infection Groups Under Actinorhizal Alnus glutinosa and Non-actinorhizal Betula nigra Trees.

    Science.gov (United States)

    Samant, Suvidha; Huo, Tian; Dawson, Jeffrey O; Hahn, Dittmar

    2016-02-01

    Quantitative polymerase chain reaction (qPCR) was used to assess the abundance and relative distribution of host infection groups of the root-nodule forming, nitrogen-fixing actinomycete Frankia in four soils with similar physicochemical characteristics, two of which were vegetated with a host plant, Alnus glutinosa, and two with a non-host plant, Betula nigra. Analyses of DAPI-stained cells at three locations, i.e., at a distance of less than 1 m (near stem), 2.5 m (middle crown), and 3-5 m (crown edge) from the stems of both tree species revealed no statistically significant differences in abundance. Frankiae generally accounted for 0.01 to 0.04 % of these cells, with values between 4 and 36 × 10(5) cells (g soil)(-1). In three out of four soils, abundance of frankiae was significantly higher at locations "near stem" and/or "middle crown" compared to "crown edge," while numbers at these locations were not different in the fourth soil. Frankiae of the Alnus host infection group were dominant in all samples accounting for about 75 % and more of the cells, with no obvious differences with distance to stem. In three of the soils, all of these cells were represented by strain Ag45/Mut15. In the fourth soil that was vegetated with older A. glutinosa trees, about half of these cells belonged to a different subgroup represented by strain ArI3. In all soils, the remaining cells belonged to the Elaeagnus host infection group represented by strain EAN1pec. Casuarina-infective frankiae were not found. Abundance and relative distribution of Frankia host infection groups were similar in soils under the host plant A. glutinosa and the non-host plant B. nigra. Results did thus not reveal any specific effects of plant species on soil Frankia populations.

  4. Nutrient supply has greater influence than sink strength on photosynthetic adaptation to CO2 elevation in white birch seedlings.

    Science.gov (United States)

    Zhang, Shouren; Dang, Qing-Lai; Cao, Bing

    2013-04-01

    To study the effects of source-sink ratio and nutrient supply on photosynthetic acclimation to CO(2) elevation, we subjected white birch seedlings to two levels of nutrient supply (high vs. low) and CO(2) concentrations (ambient vs. doubled [CO(2)]) for two months and then shaded the lower canopy on half of the seedlings to reduce source/sink ratio for an additional month. The CO(2) elevation significantly increased P(n) and IWUE at both nutrient levels but the increase was greater in the high than low nutrient treatment. The CO(2) elevation resulted in a down-regulation of V(cmax) in the low nutrient treatment but up-regulation of J(max), TPU, [Formula: see text] and J(c) in the high nutrient after 3 months of treatment. Both the CO(2) elevation and high nutrient supply increased the partition of total electron transport to carboxylation at the expense of oxidation. The seedlings responded to the shading of the lower canopy by reducing biomass allocation to roots rather than making physiological adjustments to unshaded leaves in the upper canopy. Our results suggest that the direction of photosynthetic acclimation to CO(2) elevation in white birch was nutrient-dependent and an increase in sink strength could reduce the feedback inhibition of photosynthesis.

  5. Analysis of arsenic and antimony distribution within plants growing at an old mine site in Ouche (Cantal, France) and identification of species suitable for site revegetation.

    Science.gov (United States)

    Jana, Ulrike; Chassany, Vincent; Bertrand, Georges; Castrec-Rouelle, Maryse; Aubry, Emmanuel; Boudsocq, Simon; Laffray, Daniel; Repellin, Anne

    2012-11-15

    One of the objectives of this study was to assess the contamination levels in the tailings of an old antimony mine site located in Ouche (Cantal, France). Throughout the 1.3 ha site, homogenous concentrations of antimony and arsenic, a by-product of the operation, were found along 0-0.5 m-deep profiles. Maximum concentrations for antimony and arsenic were 5780 mg kg(-1) dry tailings and 852 mg kg(-1) dry tailings, respectively. Despite the presence of the contaminants and the low pH and organic matter contents of the tailings, several patches of vegetation were found. Botanical identification determined 12 different genera/species. The largest and most abundant plants were adult pines (Pinus sylvestris), birches (Betula pendula) and the bulrush (Juncus effusus). The distribution of the metalloids within specimens of each genera/species was analysed in order to deduce their concentration and translocation capacities. This was the second goal of this work. All plant specimens were highly contaminated with both metalloids. Most were root accumulators with root to shoot translocation factors <1. Whereas contamination levels were high overall, species with both a low translocation factor and a low root accumulation coefficient were identified as suitable candidates for the complete revegetation of the site. Species combining those characteristics were the perennials P. sylvestris, B. pendula, Cytisus scoparius and the herbaceous Plantago major, and Deschampsia flexuosa.

  6. Diagnostic value of scratch-chamber test, skin prick test, histamine release and specific IgE in birch-allergic patients with oral allergy syndrome to apple

    DEFF Research Database (Denmark)

    Osterballe, M; Scheller, R; Stahl Skov, P;

    2003-01-01

    BACKGROUND: The aim of the study was to examine the diagnostic value of skin prick test (SPT), scratch-chamber test (SCT), histamine release (HR) and specific immunoglobulin E (IgE) in birch-allergic patients with oral allergy syndrome to apple. METHODS: Ten birch-allergic patients with oral alle...... a detailed case history about symptoms of oral allergy syndrome combined with a SPT with fresh apple peel or A72 will be useful.......BACKGROUND: The aim of the study was to examine the diagnostic value of skin prick test (SPT), scratch-chamber test (SCT), histamine release (HR) and specific immunoglobulin E (IgE) in birch-allergic patients with oral allergy syndrome to apple. METHODS: Ten birch-allergic patients with oral...... allergy syndrome to apple and 10 control subjects were included. All were tested with SPT, SCT, HR and specific IgE [CAP, Pharmacia, Sweden and Magic Lite (ML), ALK-ABELLO, Denmark]. RESULTS: The SPT with apple, acetone extract of apple (A72) and commercial apple extract showed sensitivities of 0.80, 0...

  7. Ozone and climate - Effects of the excess of critical loads on birches and mountain plants; Ozon og klima - effekter av taalegrenseoverskridelser paa bjoerk og fjellplanter

    Energy Technology Data Exchange (ETDEWEB)

    Mortensen, L.M.

    1996-01-01

    The conference paper relates to the environmental effects of high concentrated ozone on the biomass production in Norway. The effects on birches and mountain plants from ozone together with the interaction between ozone and carbon dioxide and their influence on vegetation are discussed

  8. 白桦BpUVR8基因的序列与表达模式分析%The sequence and expression analysis ofBpUVR8 gene in birch

    Institute of Scientific and Technical Information of China (English)

    李晓一; 詹亚光; 娄晓瑞; 曾凡锁

    2016-01-01

    As a photoreceptor speciifcally for UV-B light,BpUVR8 gene plays an important role in the photo-morphogenesis and growing development in plants. We cloned theUVR8 gene in birch, and named it as BpU-VR8 (GeneBank ID: AHY02156). The bioinformatics analysis shows that this sequence consists of 1326 bp with a complete open reading frame, and encodes 441 amino acids. Furthermore, it is a stable hydrophobic pro-tein. This protein may not contain signal peptide but have the transmembrane ability. The protein has two trans-membrane domains. According to the tertiary structure prediction, the protein is constituted by a seven-bladedβ-propeller, which has a high structural homology with AtUVR8 inArabidopsis thaliana. The expression analy-sis ofBpUVR8 indicates that this gene expressed in various tissues, and the expression level in leaves is higher than others. The expression ofBpUVR8 in August is highest. Besides, this gene is not sensitive to the induction of UV-B signal. Abiotic stress can induce the expression ofBpUVR8gene. This paper can provide a reference for the study of gene function in response to the UV-B signals.%本研究克隆了白桦(Betula platyphylla)UVR8基因,命名为BpUVR8(GenBank: AHY02156)。生物信息学分析表明该基因全长1326 bp,编码441个氨基酸,为稳定性蛋白,不存在信号肽,具有2个跨膜区。二级结构分析表明该蛋白属于混合型。三级结构预测结果显示, BpUVR8与AtUVR8蛋白结构具有较高相似性,均由7个β螺旋组成片层结构。BpUVR8表达模式分析表明,其主要在白桦叶片中表达,且8月份表达量最高;紫外诱导6 h,其转录表达水平上调约2倍;同时,非生物胁迫以及信号诱导在一定时间内也能影响该基因的转录表达。本文为研究白桦对UV-B信号的响应以及对UVR8功能的深入研究提供参考。

  9. Geochronology of Betula extensions in pollen diagrams of Alpine Late-glacial lake deposits: A case study of the Late-glacial deposits of the Gasserplatz soil archives (Vorarlberg, Austria)

    NARCIS (Netherlands)

    van Mourik, J.M.; Slotboom, R.T.; van der Plicht, J.; Streurman, H.J.; Hoek, W.J.; Kuijper, W.J.; de Graaff, L.W.S.

    2013-01-01

    Pollen diagrams of Alpine Late-glacial calcareous lake deposits show several extensions of Betula. The geochronology of these extensions cannot be based on radiocarbon dating due to reservoir effects of such lakes on the radiocarbon ages. A robust geochronology can be based on the oxygen isotope str

  10. Geochronology of Betula extensions in pollen diagrams of Alpine Late-glacial lake deposits : A case study of the Late-glacial deposits of the Gasserplatz soil archives (Vorarlberg, Austria)

    NARCIS (Netherlands)

    van Mourik, Jan M.; Slotboom, Ruud T.; van der Plicht, Johannes; Streurman, Harm Jan; Kuijper, Wim J.; Hoek, Wim Z.; de Graaff, Leo W. S.

    2013-01-01

    Pollen diagrams of Alpine Late-glacial calcareous lake deposits show several extensions of Betula. The geochronology of these extensions cannot be based on radiocarbon dating due to reservoir effects of such lakes on the radiocarbon ages. A robust geochronology can be based on the oxygen isotope str

  11. Geochronology of Betula extensions in pollen diagrams of Alpine Late-glacial lake deposits: A case study of the Late-Glacial deposits of the Gasserplatz soil archives (Vorarlberg, Austria)

    NARCIS (Netherlands)

    van Mourik, J.M.; Slotboom, R.T.; van der Plicht, J.; Streurman, H.J.; Kuijper, W.J.; Hoek, W.Z.; de Graaff, L.W.S.

    2013-01-01

    Pollen diagrams of Alpine Late-glacial calcareous lake deposits show several extensions of Betula. The geochronology of these extensions cannot be based on radiocarbon dating due to reservoir effects of such lakes on the radiocarbon ages. A robust geochronology can be based on the oxygen isotope str

  12. Energy resources of low-grade wood, small wood and waste materials. [Scots Pine; Norway Spruce; Birch

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, A.P.; Sviridyuk, E.P.

    1980-01-01

    An account is made of recent Finnish work on the potential of low-grade wood, small-dimension wood and waste material (of Scots pine, Norway spruce and birch) for power production, in the context of the current world energy crisis. The physical and economic aspects are considered, and the relevance of the Finnish research for the USSR is discussed. In 1978, wood accounted for only 1.4% of the energy balance of the USSR. Taking one t of 'standard fuel' as equal to 7000 kcal for the purposes of calculation, the energy potential of bark alone in the USSR is 13.6 million t/yr. (Refs. 6).

  13. Degradation kinetics of the main carbohydrates in birch wood during hot water extraction in a batch reactor at elevated temperatures.

    Science.gov (United States)

    Borrega, Marc; Nieminen, Kaarlo; Sixta, Herbert

    2011-11-01

    Hot water extraction of wood at elevated temperatures may be a suitable method to produce hemicellulose-lean pulps and to recover xylan-derived products from the water extract. In this study, water extractions of birch wood were conducted at temperatures between 180 and 240 °C in a batch reactor. Xylan was extensively removed, whereas cellulose was partly degraded only at temperatures above 180 °C. Under severe extraction conditions, acetic acid content in the water extract was higher than the corresponding amount of acetyl groups in wood. In addition to oligo- and monosaccharides, considerable amounts of furfural and 5-hydroxymethylfurfural (HMF) were recovered from the extracts. After reaching a maximum, the furfural yield remained constant with increasing extraction time. This maximum slightly decreased with increasing extraction temperature, suggesting the preferential formation of secondary degradation products from xylose. Kinetic models fitting experimental data are proposed to explain degradation and conversion reactions of xylan and glucan.

  14. Research into the pyrolysis of pure cellulose, lignin, and birch wood flour in the China Lake entrained-flow reactor

    Energy Technology Data Exchange (ETDEWEB)

    Diebold, J.

    1980-06-01

    This experimental program used the China Lake entrained-flow pyrolysis reactor to briefly investigate the pyrolysis of pure cellulose, pure lignin, and birch wood flour. The study determined that the cellulose and wood flour do pyrolyze to produce primarily gaseous products containing significant amounts of ethylene and other useful hydrocarbons. During attempts to pyrolyze powdered lignin, the material melted and bubbled to block the reactor entrance. The pure cellulose and wood flour produced C/sub 2/ + yields of 12% to 14% by weight, which were less than yields from an organic feedstock derived from processed municipal trash. The char yields were 0.1% by weight from cellulose and 1.5% from birch wood flour - one to two orders of magnitude less than were produced from the trash-derived feedstock. In scanning electron microscope photographs, most of the wood flour char had a sintered and agglomerated appearance, although some particles retained the gross cell characteristics of the wood flour. The appearance of the char particles indicated that the material had once been molten and possibly vapor before it formed spheroidal particles about 1 ..mu..m diameter which agglomerated to form larger char particles. The ability to completely melt or vaporize lignocellulosic materials under conditions of high heating rates has now been demonstrated in a continuous flow reactor and promises new techniques for fast pyrolysis. This char was unexpectedly attracted by a magnet, presumably because of iron contamination from the pyrolysis reactor tube wall. The production of water-insoluble tars was negligible compared to the tars produced from trash-derived feedstock. The production of water-soluble organic materials was fairly low and qualitatively appeared to vary inversely with temperature. This study was of a preliminary nature and additional studies are necessary to optimize ethylene production from these feedstocks.

  15. Birch pollen influence the severity of atopic eczema – prospective clinical cohort pilot study and ex vivo penetration study

    Directory of Open Access Journals (Sweden)

    Fölster-Holst R

    2015-10-01

    Full Text Available Regina Fölster-Holst,1 Jagoda Galecka,1 Sigo Weißmantel,1 Ute Dickschat,2 Frank Rippke,3 Kerstin Bohnsack,3 Thomas Werfel,4 Katja Wichmann,4 Matthias Buchner,1 Thomas Schwarz,1 Annika Vogt,5 Jürgen Lademann,5 Martina C Meinke5 1Department of Dermatology, Venerology and Allergy, University of Kiel, 2Wörth, 3Beiersdorf AG, Hamburg, 4Department of Dermatology, Venerology and Allergy, Division of Immunodermatology and Allergy Research, Hannover Medical School, Hannover, 5Department of Dermatology, Venerology and Allergology, Charité – Universitätsmedizin Berlin, Berlin, Germany Abstract: There is little clinical evidence for a correlation between the severity of atopic eczema (AE and pollen exposition. To obtain more data, we performed a clinical cohort pilot study about the influence of pollen on AE between sensitized and nonsensitized subjects and an experimental study addressing the cutaneous penetration of pollen into the skin. Fifty-five patients were monitored during birch pollen season. To study the cutaneous penetration, grass pollen allergens were applied on excised skin and the uptake in CD1c-expressing dendritic cells was investigated. The correlation between environmental pollen load and severity of the Scoring Atopic Dermatitis (SCORAD score and pruritus was observed, regardless of the status of sensitization. The sensitized group recovered significantly worse after the birch pollen season. Remarkably higher amounts of pollen allergens taken up by CD1c cells were detected in epidermal cells derived from skin explants with a disturbed epidermal barrier. These findings suggest an exacerbating role of pollen in AE utilizing the epidermal route. Keywords: aeroallergens, atopic eczema, seasonality, skin antigen-presenting cells, skin barrier penetration

  16. Genetic engineering of trimers of hypoallergenic fragments of the major birch pollen allergen, Bet v 1, for allergy vaccination.

    Science.gov (United States)

    Vrtala, Susanne; Fohr, Monika; Campana, Raffaela; Baumgartner, Christian; Valent, Peter; Valenta, Rudolf

    2011-03-01

    An immunotherapy trial performed in allergic patients with hypoallergenic recombinant fragments, comprising aa 1-74 and 75-160 of the major birch pollen allergen, Bet v 1, has indicated that the induction of allergen-specific IgG responses may be an important mechanism of this treatment. To investigate whether the immunogenicity of the rBet v 1 fragments can be increased, recombinant trimers of the fragments were produced. For this purpose, DNA trimers of rBet v 1 aa 1-74 as well as of rBet v 1 aa 75-160 were subcloned into expression plasmid pET 17b, expressed in Escherichia coli and purified. The fragments as well as the fragment trimers showed a reduced IgE-binding capacity and allergenic activity compared to rBet v 1 wildtype when tested in allergic patients. Both rBet v 1 aa 75-160 monomer and trimer induced high titers of allergen-specific IgG1 Abs in mice. Interestingly, rBet v 1 aa 1-74 trimer induced a much higher IgG(1) response to rBet v 1 than rBet v 1 aa 1-74 monomer. Consequently, IgG Abs induced with the rBet v 1 aa 1-74 trimer inhibited birch pollen allergic patients' IgE-binding 10-fold more efficiently than IgG Abs induced with the monomer. Our data show that the immunogenicity of allergy vaccines can be increased by oligomerization.

  17. A non-allergenic Ole e 1-like protein from birch pollen as a tool to design hypoallergenic vaccine candidates.

    Science.gov (United States)

    Marazuela, Eva G; Hajek, Roswitha; Villalba, Mayte; Barber, Domingo; Breiteneder, Heimo; Rodríguez, Rosalía; Batanero, Eva

    2012-02-01

    Recombinant DNA technology offers several approaches to convert allergens into hypoallergenic derivatives that can represent the basis of novel, safer and more effective forms of allergy vaccines. In this context, we used a new strategy for the design of a hypoallergenic derivative of Ole e 1, the main allergen of olive pollen. By screening a cDNA library from birch pollen, the clone BB18, encoding the birch counterpart of Ole e 1, was identified. In this study, BB18 has been produce in Pichia pastoris as a recombinant protein and immunologically characterized. The well-established non-allergenic properties of BB18 were used to generate a genetic variant of Ole e 1, named OB(55-58), by site-direct mutagenesis of four residues (E(55)V(56)G(57)Y(58)) in an IgE/IgG epitope of Ole e 1 by the corresponding ones in BB18 (SDSE). OB(55-58) was expressed in P. pastoris, purified to homogeneity and analyzed for IgE-reactivity by means of ELISA using sera from olive pollen allergic patients and rat basophil activation assay. T cell reactivity was assayed in a mouse model of Ole e 1 sensitization. The mutant OB(55-58) exhibited an impaired IgE reactivity, but not affected T cell reactivity, compared to wild type rOle e 1. This study emphasizes the usefulness of BB18 as a tool for epitope mapping and for engineering hypoallergenic derivatives of Ole e 1 as vaccine candidates for allergy prevention and treatment.

  18. The impact of nitration on the structure and immunogenicity of the major birch pollen allergen Bet v 1.0101.

    Science.gov (United States)

    Ackaert, Chloé; Kofler, Stefan; Horejs-Hoeck, Jutta; Zulehner, Nora; Asam, Claudia; von Grafenstein, Susanne; Fuchs, Julian E; Briza, Peter; Liedl, Klaus R; Bohle, Barbara; Ferreira, Fátima; Brandstetter, Hans; Oostingh, Gertie J; Duschl, Albert

    2014-01-01

    Allergy prevalence has increased in industrialized countries. One contributing factor could be pollution, which can cause nitration of allergens exogenously (in the air) or endogenously (in inflamed lung tissue). We investigated the impact of nitration on both the structural and immunological behavior of the major birch pollen allergen Bet v 1.0101 to determine whether nitration might be a factor in the increased incidence of allergy. Bet v 1.0101 was nitrated with tetranitromethane. Immune effects were assessed by measuring the proliferation of specific T-cell lines (TCLs) upon stimulation with different concentrations of nitrated and unmodified allergen, and by measurement of cytokine release of monocyte-derived dendritic cells (moDCs) and primary DCs (primDCs) stimulated with nitrated versus unmodified allergen. HPLC-MS, crystallography, gel electrophoresis, amino acid analysis, size exclusion chromatography and molecular dynamics simulation were performed to characterize structural changes after nitration of the allergen. The proliferation of specific TCLs was higher upon stimulation with the nitrated allergen in comparison to the unmodified allergen. An important structural consequence of nitration was oligomerization. Moreover, analysis of the crystal structure of nitrated Bet v 1.0101 showed that amino acid residue Y83, located in the hydrophobic cavity, was nitrated to 100%. Both moDCs and primDCs showed decreased production of TH1-priming cytokines, thus favoring a TH2 response. These results implicate that nitration of Bet v 1.0101 might be a contributing factor to the observed increase in birch pollen allergy, and emphasize the importance of protein modifications in understanding the molecular basis of allergenicity.

  19. Degradation effects in the extraction of antioxidants from birch bark using water at elevated temperature and pressure.

    Science.gov (United States)

    Co, Michelle; Zettersten, Camilla; Nyholm, Leif; Sjöberg, Per J R; Turner, Charlotta

    2012-02-24

    Experiments with birch bark samples have been carried to enable a distinction between extraction and degradation effects during pressurised hot water extraction. Two samples, E80 and E180, contained birch bark extracts obtained after extraction at 80 and 180°C for up to 45 min, respectively. Two other samples, P80 and P180, were only extracted for 5 min at the two temperatures and were thereafter filtered and hydrothermally treated at 80 and 180°C, respectively. During the latter treatment, samples were collected at different times to assess the stability of the extracted compounds. An offline DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, as well as a high performance liquid chromatographic separation coupled to an electrochemical detector, were used to determine the antioxidant capacity of the processed samples. The results obtained with the different techniques were compared to assess the yield of the extraction and degradation processes. In addition, an online hyphenated system comprising high performance liquid chromatography coupled to diode-array; electrochemical; and tandem mass spectrometric detection (HPLC-DAD-ECD-MS/MS) was used to study the compositions of the extracts in more detail. The results for the samples processed at 80°C showed that the extraction reached a steady-state already after 5 min, and that the extracted compounds were stable throughout the entire extraction process. Processing at 180°C, on the other hand, gave rise to partly degraded extracts with a multitude of peaks in both the diode array and electrochemical detectors, and a higher antioxidant capacity compared to for the extracts obtained at 80°C. It is concluded that HPLC-DAD-ECD is a more appropriate technique for the determination of antioxidants than the DPPH assay. The mass spectrometric results indicate that one of the extracted antioxidants, catechin, was isomerised to its diastereoisomers; (+)-catechin, (-)-catechin, (+)-epicatechin, and (-)-epicatechin.

  20. The impact of nitration on the structure and immunogenicity of the major birch pollen allergen Bet v 1.0101.

    Directory of Open Access Journals (Sweden)

    Chloé Ackaert

    Full Text Available Allergy prevalence has increased in industrialized countries. One contributing factor could be pollution, which can cause nitration of allergens exogenously (in the air or endogenously (in inflamed lung tissue. We investigated the impact of nitration on both the structural and immunological behavior of the major birch pollen allergen Bet v 1.0101 to determine whether nitration might be a factor in the increased incidence of allergy. Bet v 1.0101 was nitrated with tetranitromethane. Immune effects were assessed by measuring the proliferation of specific T-cell lines (TCLs upon stimulation with different concentrations of nitrated and unmodified allergen, and by measurement of cytokine release of monocyte-derived dendritic cells (moDCs and primary DCs (primDCs stimulated with nitrated versus unmodified allergen. HPLC-MS, crystallography, gel electrophoresis, amino acid analysis, size exclusion chromatography and molecular dynamics simulation were performed to characterize structural changes after nitration of the allergen. The proliferation of specific TCLs was higher upon stimulation with the nitrated allergen in comparison to the unmodified allergen. An important structural consequence of nitration was oligomerization. Moreover, analysis of the crystal structure of nitrated Bet v 1.0101 showed that amino acid residue Y83, located in the hydrophobic cavity, was nitrated to 100%. Both moDCs and primDCs showed decreased production of TH1-priming cytokines, thus favoring a TH2 response. These results implicate that nitration of Bet v 1.0101 might be a contributing factor to the observed increase in birch pollen allergy, and emphasize the importance of protein modifications in understanding the molecular basis of allergenicity.

  1. Study on Precipitation Hydro-chemical Characteristic of Different Stages of Betula platyphylla Secondary Forest%不同林龄白桦次生林降雨水化学特征研究

    Institute of Scientific and Technical Information of China (English)

    李文影; 满秀玲; 张阳武

    2009-01-01

    This paper measured the precipitation, throughfall, stemflow and litter water in the Cl~- ,NH_4~+-N, Na~+ , NO_3~--N, TN, K~+ , Ca~(2+) ,Mg~(2+) of different stages of Betula platyphylla secondary forest . The paper studied the different properties of hydro-chemical between four different stages of Betula platyphylla secondary forest. The results showed: In precipitation the highest concentration was for Ca~(2+) and the lowest concentration was for Na~+. The average concentration of elements(in mg/L total) for the order Ca~(2+)>C1~-> K~+>N0_3~- —N>Mg~(2+)> Na~+ , the amount of each element was very various in terms of seasons alternate and in which the change of Cl~- was the smallest. NO_3~- - N and Ca~(2+) of throughfall was the lowest content in 25 year-old of Betula platyphylla secondary forest, Cl~- and Mg~(2+)of throughfall was the lowest concentration in38 year-old of Betula platyphylla secondary forest,Na~+ ,K~+ , Mg~(2+) of throughfall was the lowest concentration in 56 year-old of Betula platyphylla secondary forest. Cl~-, NO_3~--N, K~+ of stemflow was the lowest concentration in 38 year-old of Betula platyphylla secondary forest, Na~+ , Ca~(2+) and Mg~(2+) of stemflow was the lowest concentration in 56 year-old of Betula platyphylla secondary forest. Cl~- , NH_4~- -N, Na~+and K~+ of litter wate was the lowest concentration in 25 year-old of Betula platyphylla secondary forest,Mg~(2+) , Mn of litter wate was the lowest concentration in 38 year-old of Betula platyphylla secondary forest. Ca~(2+) of litter water was the lowest concentration in 56 year-old of Betula platyphylla secondary forest.%通过对不同林龄白桦次生林林外降雨、穿透雨、树干茎流和枯透水中的Cl~-,NO_3~-N,Na~+,K~+,Ca2-,Mg~(2+)等进行测定,以研究4个林龄之间降水化学性质的差异.结果表明:林外降雨中Ca~(2+)的含量最高,Na~+含量最低,养分元素平均含量(以mg/L计)排列顺序为:Ca~(2+)>Cl~->K~+>NO_3~--N>Mg~(2+)>Na~+,各元素在

  2. 珍稀植物蓑衣油杉濒危机制的初步研究%Primary Study on the Endangered Mechanism of the Rare Plant Keteleeria evelyniana var.pendula

    Institute of Scientific and Technical Information of China (English)

    牟凤娟; 戴兴芬; 马士祝; 邓长仙

    2013-01-01

    The geographical distribution and natural habitats,as well as the population size and the age structure of the population of Keteleeria evelyniana var.pendula in Huaning County,Yunnan Province were studied in this paper,and the biological characteristics,such as the morphological features,the development rule of the growth and its spreading and germination of seeds were well knew.It was concluded that K.evelyniana var.pendula was mainly distributed in the mountain areas near villages,such as Pingdi and Mada in Huaning County; the existing groups of this variety were the small populations,the clustering populations were characterized by the illogical age structure,and the populations were in a relatively unsteady stage.Although the characteristics of the seed wing were good for spreading over long distances,the seed yield was extremely low and the transformation of seeds to seedling is difficult.Therefore,the sexual reproduction was suffocated and the life history tended to break,which is an important one of the internal reasons that results in its being endangered condition at last.Furthermore,the survival of this species is severely threatened by the natural habitats being seriously damaged and the adults being excessively excavated,which is the main external reasons that cause the dramatical decreasing of the individuals in the wild population.The effective measures of protection and utilization were proposed,based on the endangered mechanism of K.evelyniana var.pendula.%对云南特有珍稀植物蓑衣油杉(Keteleeria evelyniana var.pendula)的地理分布、自然生境概况及种群大小和年龄结构等种群特性进行研究,并掌握其形态特征、生长发育规律及种子散布和萌发等生物学特性.结果表明:蓑衣油杉在云南省华宁县主要分布于平地和吗哒等山区村寨周边地区;现有蓑衣油杉自然居群均为小种群,高群集分布,年龄结构不合理,种群处于相对不稳定阶段;虽然种子的种

  3. Projectiles, pendula, and special relativity

    CERN Document Server

    Price, R H

    2005-01-01

    The kind of flat-earth gravity used in introductory physics appears in an accelerated reference system in special relativity. From this viewpoint, we work out the special relativistic description of a ballistic projectile and a simple pendulum, two examples of simple motion driven by earth-surface gravity. The analysis uses only the basic mathematical tools of special relativity typical of a first-year university course.

  4. ANTIMICROBIAL ACTIVITY OF THE SUBSTANCES RECEIVED FROM RAW MATERIALS OF BIRCH FAMILY PLANTS

    Directory of Open Access Journals (Sweden)

    Fedchenkova Yu.A

    2016-12-01

    Full Text Available Introduction. In accordance with the last events in Ukraine (considering military operations in anti-terrorist operation in the Luhansk and Donetsk regions the domestic medicine is in great need in preparations with antimicrobial activity. Our attention as the sources of receiving biologically active substances with antimicrobial activity was drawn with birch Betulaceae family plants – hazel ordinary Corylus avellana L. and black alder Alnus glutinosa (L. Gaertn. It is known that in medicine the leaves of hazel ordinary are used as antiseptic, anti-inflammatory, vesselrestorative drug, and the leaves of black alder reveal the antiinflammatory, astringent, wound healing, spasmolytic and choleretic action. However, the drugs with antimicrobial action received from the leaves of these plants are absent on the market of Ukraine. Therefore the studying of antimicrobial activity of this type of raw materials received from hazel ordinary and black alder, for creation of new medicines, is now one of the main directions in pharmacy. For this purpose we have revealed tinctures, spirit, lipophilic and polysacharid fractions received from the leaves of hazel ordinary and black alder. The purpose of our research is studying of antimicrobial activity of revealed substance received from the leaves of black alder and hazel ordinary. Materials and methods. There were being examined tinctures, lipophilic, spirit and polysacharid fractions received from the leaves of hazel ordinary and black alder. The test of antimicrobial effect of substances was carried out by means of serial dilution concerning the following six reference cultures: Staphylococcus aureus ATCC 6538-P, Candida albicans ATCC 885-653, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6833, Bacillus cereus ATCC 10702, Pseudomonas aeruginosa ATCC 9027, according to the State Pharmacopoeia of Ukraine, in the Department of Microbiology and Immunology of KMAPE. For the experiment there was prepared

  5. Effects of elevated CO2 on litter chemistry and subsequent invertebrate detritivore feeding responses.

    Directory of Open Access Journals (Sweden)

    Matthew W Dray

    Full Text Available Elevated atmospheric CO2 can change foliar tissue chemistry. This alters leaf litter palatability to macroinvertebrate detritivores with consequences for decomposition, nutrient turnover, and food-web structure. Currently there is no consensus on the link between CO2 enrichment, litter chemistry, and macroinvertebrate-mediated leaf decomposition. To identify any unifying mechanisms, we presented eight invertebrate species from aquatic and terrestrial ecosystems with litter from Alnus glutinosa (common alder or Betula pendula (silver birch trees propagated under ambient (380 ppm or elevated (ambient +200 ppm CO2 concentrations. Alder litter was largely unaffected by CO2 enrichment, but birch litter from leaves grown under elevated CO2 had reduced nitrogen concentrations and greater C/N ratios. Invertebrates were provided individually with either (i two litter discs, one of each CO2 treatment ('choice', or (ii one litter disc of each CO2 treatment alone ('no-choice'. Consumption was recorded. Only Odontocerum albicorne showed a feeding preference in the choice test, consuming more ambient- than elevated-CO2 birch litter. Species' responses to alder were highly idiosyncratic in the no-choice test: Gammarus pulex and O. albicorne consumed more elevated-CO2 than ambient-CO2 litter, indicating compensatory feeding, while Oniscus asellus consumed more of the ambient-CO2 litter. No species responded to CO2 treatment when fed birch litter. Overall, these results show how elevated atmospheric CO2 can alter litter chemistry, affecting invertebrate feeding behaviour in species-specific ways. The data highlight the need for greater species-level information when predicting changes to detrital processing-a key ecosystem function-under atmospheric change.

  6. Uses of tree saps in northern and eastern parts of Europe

    Directory of Open Access Journals (Sweden)

    Ingvar Svanberg

    2012-12-01

    Full Text Available In this article we review the use of tree saps in northern and eastern Europe. Published accounts by travellers, ethnologists and ethnobotanists were searched for historical and contemporary details. Field observations made by the authors have also been used. The presented data shows that the use of tree sap has occurred in most north and eastern European countries. It can be assumed that tree saps were most used where there were extensive stands of birch or maple trees, as these two genera generally produce the largest amount of sap. The taxa most commonly used have been Betula pendula, B. pubescens, and Acer platanoides, but scattered data on the use of several other taxa are presented. Tree sap was used as a fresh drink, but also as an ingredient in food and beverages. It was also fermented to make light alcoholic products like ale and wine. Other folk uses of tree saps vary from supplementary nutrition in the form of sugar, minerals and vitamins, to cosmetic applications for skin and hair and folk medicinal use. Russia, Ukraine, Belarus, Estonia, Latvia and Lithuania are the only countries where the gathering and use of sap (mainly birch sap has remained an important activity until recently, due to the existence of large birch forests, low population density and the incorporation of sap into the former Soviet economic system. It is evident that gathering sap from birch and other trees was more widespread in earlier times. There are records indicating extensive use of tree saps from Scandinavia, Poland, Slovakia and Romania, but it is primarily of a historical character. The extraction of tree sap in these countries is nowadays viewed as a curiosity carried out only by a few individuals. However, tree saps have been regaining popularity in urban settings through niche trading.

  7. [Molecular aspects of allergy to plant products. Part II. Pathogenesis-related proteins (PRs), apple allergenicity governed by Mal d 1 gene].

    Science.gov (United States)

    Bokszczanin, Kamila Ł; Przybyła, Andrzej A

    2012-03-01

    Of the plant allergens listed in the Official Allergen Database of the International Union of Immunological Societies, approximately 25% belong to the group of pathogenesis-related proteins (PRs). They have been classified into 17 PR families based on similarities in their amino acid sequence, enzymatic activities, or other functional properties. Plant-derived allergens have been identified with sequence similarities to PR families 2, 3, 4, 5, 8, 10, and 14. The main birch allergen in northern Europe is a class 10 (PR-10) protein from the European white birch (Betula pendula) termed Bet v 1. Pollen of other Fagales species contains PR-10 homologues that share epitopes with Bet v 1, as do several fruits, nuts and vegetables. Among the plant food fruits of the Rosaceae family are the most frequently responsible for allergenic reactions. It is documented, that approximately 2% of European population is allergic to apples. The article presents molecular characterization of PR-10 proteins with regard to their structure and function as well as apple Mal d 1 gene-determined allergenicity.

  8. Online Measurement of Real-Time Cytotoxic Responses Induced by Multi-Component Matrices, such as Natural Products, through Electric Cell-Substrate Impedance Sensing (ECIS).

    Science.gov (United States)

    Fallarero, Adyary; Batista-González, Ana E; Hiltunen, Anna K; Liimatainen, Jaana; Karonen, Maarit; Vuorela, Pia M

    2015-11-12

    Natural products are complex matrices of compounds that are prone to interfere with the label-dependent methods that are typically used for cytotoxicity screenings. Here, we developed a label-free Electric Cell-substrate Impedance Sensing (ECIS)-based cytotoxicity assay that can be applied in the assessment of the cytotoxicity of natural extracts. The conditions to measure the impedance using ECIS were first optimized in mice immortalized hypothalamic neurons GT1-7 cells. The performance of four natural extracts when tested using three conventional cytotoxicity assays in GT1-7 cells, was studied. Betula pendula (silver birch tree) was found to interfere with all of the cytotoxicity assays in which labels were applied. The silver birch extract was also proven to be cytotoxic and, thus, served as a proof-of-concept for the use of ECIS. The extract was fractionated and the ECIS method permitted the distinction of specific kinetic patterns of cytotoxicity on the fractions as well as the extract's pure constituents. This study offers evidence that ECIS is an excellent tool for real-time monitoring of the cytotoxicity of complex extracts that are difficult to work with using conventional (label-based) assays. Altogether, it offers a very suitable cytotoxicity-screening assay making the work with natural products less challenging within the drug discovery workflow.

  9. Online Measurement of Real-Time Cytotoxic Responses Induced by Multi-Component Matrices, such as Natural Products, through Electric Cell-Substrate Impedance Sensing (ECIS

    Directory of Open Access Journals (Sweden)

    Adyary Fallarero

    2015-11-01

    Full Text Available Natural products are complex matrices of compounds that are prone to interfere with the label-dependent methods that are typically used for cytotoxicity screenings. Here, we developed a label-free Electric Cell-substrate Impedance Sensing (ECIS-based cytotoxicity assay that can be applied in the assessment of the cytotoxicity of natural extracts. The conditions to measure the impedance using ECIS were first optimized in mice immortalized hypothalamic neurons GT1-7 cells. The performance of four natural extracts when tested using three conventional cytotoxicity assays in GT1-7 cells, was studied. Betula pendula (silver birch tree was found to interfere with all of the cytotoxicity assays in which labels were applied. The silver birch extract was also proven to be cytotoxic and, thus, served as a proof-of-concept for the use of ECIS. The extract was fractionated and the ECIS method permitted the distinction of specific kinetic patterns of cytotoxicity on the fractions as well as the extract’s pure constituents. This study offers evidence that ECIS is an excellent tool for real-time monitoring of the cytotoxicity of complex extracts that are difficult to work with using conventional (label-based assays. Altogether, it offers a very suitable cytotoxicity-screening assay making the work with natural products less challenging within the drug discovery workflow.

  10. 白桦天然次生林种群生态特征的研究%Study on Population Characteristic of Betula Platyphylla Natural Secondary Forest

    Institute of Scientific and Technical Information of China (English)

    卫晶; 赵惠玲; 毕润成; 苗艳明

    2012-01-01

    Based on the field data about Betula platyphyUa population and the theory of survival analysis, the authors worked out a static life table of Betula platyphylla, drew the curves of mortality rate, survival rate, killing value, survival rate function, mortality density function, cumulative mortality rate and hazard rate function, and analyzed the life process of population. The analysis on the age structures of Betula platyphylla populations showed that the young and middle individuals were relatively rich and the number of old individuals is in short. The survival curves of Betula platyphylla populations belonged to the Deevey I[. The monotony of cumulative mortality rate increases, while that of survival function decreases. The change of increase and decrease is that the beginning is higher than the later. This shows that in the beginning the mortality rate is higher, while at the later stage the population is relatively stable. The number of old individuals would increases at the beginning and decreases finally in 20, 40, 60, 80years lately. It is difficult to maintain the population stability.%采用样地调查的方法,对太岳山七里峪白桦林种群进行了年龄结构分析、编制了静态生命表、绘制了存活曲线,并对该种群的四个函数(生存函数、积累死亡函数、死亡密度函数、危险率函数)进行数量分析,结果表明:①七里峪白桦种群龄级分布,不同环境下种群结构稍有差异:种群A、种群D为增长型种群,种群B、种群C、种群E趋向于稳定型.②白桦种群存活曲线接近于DeeveyⅡ型.③积累死亡率单调上升,生存率呈单调下降,上升或下降幅度前期大于后期,说明白桦种群在前期死亡率高,而种群后期则相对稳定.④在未来20年、40年、60年和80年中,白桦种群将呈现老龄级株数先增后减的趋势,种群稳定性长期维持较为困难.

  11. Modeling of stomatal conductance to estimate stomatal ozone uptake by Fagus crenata, Quercus serrata, Quercus mongolica var. crispula and Betula platyphylla.

    Science.gov (United States)

    Kinose, Yoshiyuki; Azuchi, Fumika; Uehara, Yui; Kanomata, Tomoaki; Kobayashi, Ayumi; Yamaguchi, Masahiro; Izuta, Takeshi

    2014-11-01

    To construct stomatal conductance models and estimate stomatal O3 uptake for Fagus crenata, Quercus serrata, Quercus mongolica var. crispula and Betula platyphylla, stomatal conductance (gs) was measured in seedlings of the four tree species. Better estimates of gs were made by incorporating the acute effects of O3 on gs into the models and the models could explain 34-52% of the variability in gs. Although the O3 concentration was relatively high in spring from April to May, COU of F. crenata, Q. serrata and Q. mongolica var. crispula were relatively low and the ratios of COU in spring to total COU in one year were 16.8% in all tree species because of low gs limited mainly by leaf pre-maturation and/or low temperature. The COU of B. platyphylla were relatively high mainly because of rapid leaf maturation and lower optimal temperature for stomatal opening.

  12. Assessment of hydrology, water quality, and trace elements in selected placer-mined creeks in the birch creek watershed near central, Alaska, 2001-05

    Science.gov (United States)

    Kennedy, Ben W.; Langley, Dustin E.

    2007-01-01

    Executive Summary The U.S. Geological Survey, in cooperation with the Bureau of Land Management, completed an assessment of hydrology, water quality, and trace-element concentrations in streambed sediment of the upper Birch Creek watershed near Central, Alaska. The assessment covered one site on upper Birch Creek and paired sites, upstream and downstream from mined areas, on Frying Pan Creek and Harrison Creek. Stream-discharge and suspended-sediment concentration data collected at other selected mined and unmined sites helped characterize conditions in the upper Birch Creek watershed. The purpose of the project was to provide the Bureau of Land Management with baseline information to evaluate watershed water quality and plan reclamation efforts. Data collection began in September 2001 and ended in September 2005. There were substantial geomorphic disturbances in the stream channel and flood plain along several miles of Harrison Creek. Placer mining has physically altered the natural stream channel morphology and removed streamside vegetation. There has been little or no effort to re-contour waste rock piles. During high-flow events, the abandoned placer-mine areas on Harrison Creek will likely contribute large quantities of sediment downstream unless the mined areas are reclaimed. During 2004 and 2005, no substantial changes in nutrient or major-ion concentrations were detected in water samples collected upstream from mined areas compared with water samples collected downstream from mined areas on Frying Pan Creek and Harrison Creek that could not be attributed to natural variation. This also was true for dissolved oxygen, pH, and specific conductance-a measure of total dissolved solids. Sample sites downstream from mined areas on Harrison Creek and Frying Pan Creek had higher median suspended-sediment concentrations, by a few milligrams per liter, than respective upstream sites. However, it is difficult to attach much importance to the small downstream increase

  13. Birch's law for high-pressure metals and ionic solids: Sound velocity data comparison between shock wave experiments and recent diamond anvil cell experiments

    Science.gov (United States)

    Boness, David A.; Ware, Lucas

    2017-01-01

    Sound velocity-density systematics has long been a fruitful way to take shock wave measurements on elements, alloys, oxides, rocks, and other materials, and allow reasonable extrapolation to densities found deep in the Earth. Recent detection of super-Earths has expanded interest in terrestrial planetary interiors to an even greater range of materials and pressures. Recent published diamond anvil cell (DAC) experimental measurements of sound velocities in iron and iron alloys, relevant to planetary cores, are inconsistent with each other with regard to the validity of Birch's Law, a linear relation between sound velocity and density. We examine the range of validity of Birch's Law for several shocked metallic elements, including iron, and shocked ionic solids and make comparisons to the recent DAC data.

  14. Implications of Elevated Atmospheric Carbon Dioxide and Tropospheric Ozone for Water Use in Stands of Trembling Aspen and Paper Birch

    Science.gov (United States)

    Rhea, Lee Kirk

    Projected increases in the atmospheric concentration of CO2 and tropospheric O3 over the next 50 years are of concern due in part to their potential to affect forest water budgets. I conducted a series of studies at the Aspen Free Air CO2 and O3 Enrichment experiment near Rhinelander, WI to determine the effect of projected concentrations of these gases for the year 2050 on the water budget in stands of trembling aspen and paper birch. In order to determine the effects of elevated CO2 (eCO 2) and O3 (eO3) on rainfall partitioning between interception, through fall, and stem flow I performed a computerized analysis of photographed canopy branches and compared the results to hydrologic measurements. Elevated O3 significantly decreased total aspen and birch branch length, resulting in net decreases for 2002 whorls of -18 % and 2006 whorls of -16 %. Some of these changes had measurable effects on rainfall partitioning. The biomass of fine roots has been observed to change in response to eCO2 and eO3 at shallow depths, but little work has been done to assess deeper roots. I characterized fine root responses to eCO 2 and eO3 to a depth of one meter. Fumigation with O 3 increased small root biomass in shallow soil 30 % in all aspen plots and decreased root biomass in shallow soil 46 % in aspen-birch plots. Increases in root length up to 131 % and specific root length up to 77 % occurred under eO3 in middle and deep soil layers, indicating more extensive soil exploration at depth. Small root biomass in shallow soils increased 20 % to 24 % under eCO2, indicative of more intensive soil exploration near the surface. Previous studies of sapwood from Aspen-FACE indicated that anatomical structures related to hydraulic conductance (K) differed between aspen clones and that they responded to the treatments differently. I constructed embolism curves for stem wood samples collected below the base of the live crowns. There were no significant treatment effects on K at full water

  15. Age-dependent sensitization to the 7S-vicilin-like protein Cor a 11 from hazelnut (Corylus avellana) in a birch-endemic region

    OpenAIRE

    Verweij, MM; Hagendorens, MM; Trashin, Stanislav; Cucu, Tatiana; De Meulenaer, Bruno; Devreese, Bart; Bridts, CH; De Clerck, LS; Ebo, DG

    2012-01-01

    Background: Hazelnut (Corylus avellana) allergy exhibits age and geographically distinct sensitization patterns that have not yet been fully resolved. Objective: To study sensitization to Cor a 11 in different age groups of hazelnut-allergic patients and infants with atopic dermatitis (AD) sensitized to hazelnut in a birch-endemic region. Methods: Sera from 80 hazelnut-allergic patients, 33 infants under 1 year of age with AD (24 sensitized and 9 not sensitized to hazelnut), 32 healthy ...

  16. Effects of soil temperature and elevated atmospheric CO{sub 2} concentration on gas exchange, in vivo carboxylation and chlorophyll fluorescence in jack pine and white birch seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S.; Dang, Q-L. [Lakehead University, Faculty of Forestry and the Forest Environment, Thunder Bay, ON (Canada)

    2005-05-01

    The interactive effects of soil temperature and elevated carbon dioxide on the photosynthetic functions of white birch and jack pine were investigated. Elevated carbon dioxide was found to significantly decrease the allocation of electron transport to photorespiration in both species by increasing electron allocation to Rubisco carboxylation. Photosynthetic down-regulation occurred in both species after four months in elevated carbon dioxide as evidenced by decreases in maximal carboxylation rate which were unaffected by soil temperature. 50 refs., 5 figs.

  17. Sap flux in pure aspen and mixed aspen-birch forests exposed to elevated concentrations of carbon dioxide and ozone.

    Science.gov (United States)

    Uddling, Johan; Teclaw, Ronald M; Kubiske, Mark E; Pregitzer, Kurt S; Ellsworth, David S

    2008-08-01

    Elevated concentrations of atmospheric carbon dioxide ([CO2]) and tropospheric ozone ([O3]) have the potential to affect tree physiology and structure and hence forest water use, which has implications for climate feedbacks. We investigated how a 40% increase above ambient values in [CO2] and [O3], alone and in combination, affect tree water use of pure aspen and mixed aspen-birch forests in the free air CO2-O3 enrichment experiment near Rhinelander, Wisconsin (Aspen FACE). Measurements of sap flux and canopy leaf area index (L) were made during two growing seasons, when steady-state L had been reached after more than 6 years of exposure to elevated [CO2] and [O3]. Maximum stand-level sap flux was not significantly affected by elevated [O3], but was increased by 18% by elevated [CO2] averaged across years, communities and O(3) regimes. Treatment effects were similar in pure aspen and mixed aspen-birch communities. Increased tree water use in response to elevated [CO2] was related to positive CO2 treatment effects on tree size and L (+40%). Tree water use was not reduced by elevated [O3] despite strong negative O3 treatment effects on tree size and L (-22%). Elevated [O3] predisposed pure aspen stands to drought-induced sap flux reductions, whereas increased tree water use in response to elevated [CO2] did not result in lower soil water content in the upper soil or decreasing sap flux relative to control values during dry periods. Maintenance of soil water content in the upper soil in the elevated [CO2] treatment was at least partly a function of enhanced soil water-holding capacity, probably a result of increased organic matter content from increased litter inputs. Our findings that larger trees growing in elevated [CO2] used more water and that tree size, but not maximal water use, was negatively affected by elevated [O3] suggest that the long-term cumulative effects on stand structure may be more important than the expected primary stomatal closure responses to

  18. Experimental study comparing the behaviour of steel truss plates and birch plywood inserts in ridge joints on glued laminated rafters

    Directory of Open Access Journals (Sweden)

    López Gayarre, F.

    2009-08-01

    Full Text Available The present paper reports on an analysis of the mechanical performance of two flat joining systems used in roof members made of glued laminated timber.Six pairs of laminated timber rafters for a double-pitched roof with a 100x180-mm cross-section, a 6.00-m span and a height of 1.00 m were subjected to full-scale four-point bending. In three of the specimens the rafters were joined at the ridge with a birch plywood insert, while in the other three the connection was secured with a fitting consisting in a standard flat steel truss plate. The objective pursued was to evaluate the possibility of replacing the steel fittings with birch plywood inserts. The approach adopted to reach this objective was to compare the strength of the two joint pieces and the deformation generated in the overall structure during strength tests.The results proved to be highly satisfactory in terms of both the bearing capacity and the stiffness of the structures tested.El presente trabajo tiene por objeto llevar a cabo un análisis experimental del comportamiento mecánico de ciertos sistemas planos de unión para elementos estructurales de madera laminada empleados en la construcción de cubiertas.El estudio incluye los ensayos a escala real de seis din-teles a dos aguas de madera laminada, de 6 m de luz, 1 m de altura y una sección de 100 mm x 180 mm, sometidos a flexión en cuatro puntos. En tres dinteles el elemento de unión es una pieza de tablero contra-chapado de abedul, mientras que en los otros tres se ha utilizado un herraje de acero. La finalidad es valorar la posibilidad de sustituir los elementos de unión, realizados mediante herrajes, por otros constituidos por piezas de tablero contrachapado de abedul. Este objetivo se logra comparando el comportamiento resistente mostrado por ambos dispositivos de unión, y las deformaciones en cada caso de las estructuras completas.Los resultados resultaron muy satisfactorios tanto en la capacidad portante como en la

  19. Karyotype reorganisation in the subtilis group of birch mice (Rodentia, Dipodidae, Sicista): unexpected taxonomic diversity within a limited distribution.

    Science.gov (United States)

    Kovalskaya, Y M; Aniskin, V M; Bogomolov, P L; Surov, A V; Tikhonov, I A; Tikhonova, G N; Robinson, T J; Volobouev, V T

    2011-01-01

    Conventional cytogenetic studies of Sicista subtilis and S. severtzovi (Dipodidae, Sicistinae), both attributable to the subtilis group of birch mice, revealed extensive karyotype diversity with 2n = 16-26 and NFa values of 26-46 indicating the overwhelming non-Robertsonian nature of chromosomal reorganization in these species. The numerical and structural chromosome variability was principally found in specimens located within a confined region of the East European (Russian) Plain. The approximately 135,000-km(2) area occurs in the vicinity of the Don River bend between 49°13'N/43°46'E and 51°32'N/36°16'E. The detection of cytotypes sharing similar 2n and NF values, but having morphologically distinct chromosomes, suggests that these may result from polymorphisms present both within recognized species and in cryptic taxa not hitherto described. We conducted a comprehensive, comparative chromosome banding analysis of 52 birch mice (21 localities) referable to the subtilis group and report the presence of 5 distinct karyotypes, each characterized by a combination of stable, variable, and partly overlapping 2n/NFa values. These karyotypes differed from each other by 10-29 structural chromosomal rearrangements (18.1 ± 6.3) that comprised Rb fusions/fissions (42.2%), pericentric inversions (31.1%), and tandem translocations (22.2%). The composition, and the high numbers of these chromosomal changes, is likely to provide an effective means of post-mating isolation, suggesting that taxonomic diversity within the subtilis group is larger than currently accepted. Additionally, we report the frequent fixation of tandem translocations in sample populations, one of which was found in a polymorphic state representing, as far as we are aware, the first case of an in statu nascendi tandem fusion in wild populations. Moreover, our data revealed that bi-armed chromosomes were involved in fusions detected in some of the subtilis taxa. In each instance, however, fusions were

  20. Influence of the Oil Phase and Topical Formulation on the Wound Healing Ability of a Birch Bark Dry Extract.

    Science.gov (United States)

    Steinbrenner, Isabel; Houdek, Pia; Pollok, Simone; Brandner, Johanna M; Daniels, Rolf

    2016-01-01

    Triterpenes from the outer bark of birch are known for various pharmacological effects including enhanced wound healing (WH). A birch bark dry extract (TE) obtained by accelerated solvent extraction showed the ability to form oleogels when it is suspended in oils. Consistency of the oleogels and the dissolved amount of triterpenes varies largely with the used oil. Here we wanted to know to what extent different oils and formulations (oleogel versus o/w emulsion) influence WH. Looking at the plain oils, medium-chain triglycerides (MCT) enhanced WH (ca. 1.4-fold), while e.g. castor oil (ca.0.3-fold) or light liquid paraffin (LLP; ca. 0.5-fold) significantly decreased WH. Concerning the respective oleogels, TE-MCT showed no improvement although the solubility of the TE was high. In contrast, the oleogel of sunflower oil which alone showed a slight tendency to impair WH, enhanced WH significantly (ca. 1.6-fold). These results can be explained by release experiments where the release rate of betulin, the main component of TE, from MCT oleogels was significantly lower than from sunflower oil oleogels. LLP impaired WH as plain oil and even though it released betulin comparable to sunflower oil it still results in an overall negative effect of the oleogel on WH. As a further formulation option also surfactant free o/w emulsions were prepared using MCT, sunflower oil and LLP as a nonpolar oil phase. Depending on the preparation method (suspension or oleogel method) the distribution of the TE varied markedly and affected also release kinetics. However, the released betulin was clearly below the values measured with the respective oleogels. Consequently, none of the emulsions showed a significantly positive effect on WH. In conclusion, our data show that the oil used as a vehicle influences wound healing not only by affecting the release of the extract, but also by having its own vehicle effect on wound healing. This is also of importance for other applications where drugs

  1. The partial reduction of electron-deficient pyrroles: procedures describing both Birch (Li/NH3) and ammonia-free (Li/DBB) conditions.

    Science.gov (United States)

    Donohoe, Timothy J; Thomas, Rhian E

    2007-01-01

    The partial reduction of electron-deficient pyrroles using either Birch (Li/NH(3)) or ammonia-free (Li/di-tert-butyl biphenyl) conditions allows formation of pyrroline compounds in good yield and, when combined with a reductive alkylation or similar approach, leads to highly functionalized, synthetically useful compounds. This methodology has been proven in the syntheses of several complex natural products, all of which show interesting biological activity. This protocol describes in detail the following stages of the partial reduction procedure: formation of the reducing solution, partial reduction of the pyrrole compound and finally quench of the resulting anion/dianion using either protonating agents or an aldehyde. The ammonia-free conditions described herein are particularly useful for reactions requiring the use of reactive electrophiles, such as acid chlorides or enolizable aldehydes, which are incompatible with the standard Birch reduction conditions. The reaction procedure for the ammonia Birch reduction (procedure A) takes about 9.5 h to complete. Those described for the ammonia-free reductions, procedure B and procedure C, can be expected to take approximately 33 and 8 h, respectively.

  2. Evaluation of the mechanism of gelation of an oleogel based on a triterpene extract from the outer bark of birch.

    Science.gov (United States)

    Grysko, M; Daniels, R

    2013-07-01

    Oleogels are known for their high physical, chemical, and mechanical stability and good in vivo efficacy, which make them appropriate vehicles for dermal drug delivery and skin care for very dry skin. Modern formulation research focusses on well tolerated and sustainable formulation concepts. This paper deals with an innovative oleogel, which is based on a triterpene dry extract from the outer bark of birch (TE). In this formulation TE does not only act as an excipient but provides interesting pharmacological properties at the same time. The oleogel was formulated using solely Simmondsia Chinensis seed oil (jojoba oil) and TE. Fluorescence microscopy and confocal Raman microscopy showed that suspended TE particles arrange in a three-dimensional gel network. Infrared spectroscopy revealed that the formation of hydrogen bonds between TE particles is responsible for the self-assembly of TE in oil. Moreover, the influence of TE concentration and morphology of the TE particles on the viscoelasticity of the resulting oleogels was analyzed. Gel strength increased with TE concentration and was critical to the specific surface area of the TE particles.

  3. Searching for magnetism in hydrogenated graphene: using highly hydrogenated graphene prepared via Birch reduction of graphite oxides.

    Science.gov (United States)

    Eng, Alex Yong Sheng; Poh, Hwee Ling; Šaněk, Filip; Maryško, Miroslav; Matějková, Stanislava; Sofer, Zdeněk; Pumera, Martin

    2013-07-23

    Fully hydrogenated graphene (graphane) and partially hydrogenated graphene materials are expected to possess various fundamentally different properties from graphene. We have prepared highly hydrogenated graphene containing 5% wt of hydrogen via Birch reduction of graphite oxide using elemental sodium in liquid NH3 as electron donor and methanol as proton donor in the reduction. We also investigate the influence of preparation method of graphite oxide, such as the Staudenmaier, Hofmann or Hummers methods on the hydrogenation rate. A control experiment involving NaNH2 instead of elemental Na was also performed. The materials were characterized in detail by electron microscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy both at room and low temperatures, X-ray fluorescence spectroscopy, inductively coupled plasma optical emission spectroscopy, combustible elemental analysis and electrical resistivity measurements. Magnetic measurements are provided of bulk quantities of highly hydrogenated graphene. In the whole temperature range up to room temperature, the hydrogenated graphene exhibits a weak ferromagnetism in addition to a contribution proportional to field that is caused not only by diamagnetism but also likely by an antiferromagnetic influence. The origin of the magnetism is also determined to arise from the hydrogenated graphene itself, and not as a result of any metallic impurities.

  4. [Short-term effects of fire disturbance on greenhouse gases emission from Betula platyphylla-forested wetland in Xiaoxing'an Mountains, Northeast China].

    Science.gov (United States)

    Mu, Chang-cheng; Zhang, Bo-wen; Han, Li-dong; Yu, Li-li; Gu, Han

    2011-04-01

    By the methods of static chamber and gas chromatography, this paper studied the effects of fire disturbance on the seasonal dynamics and source/sink functions of CH4, CO2 and N2O emissions from Betula platyphylla-forested wetland as well as their relations with environmental factors in Xiaoxing' an Mountains of China. In growth season, slight fire disturbance on the wetland induced an increase of air temperature and ground surface temperature by 1.8-3.9 degrees C and a decrease of water table by 6.3 cm; while heavy fire disturbance led to an increase of air temperature and 0-40 cm soil temperature by 1.4-3.8 degrees C and a decrease of water table by 33.9 cm. Under slight or no fire disturbance, the CH4 was absorbed by the wetland soil in spring but emitted in summer and autumn; under heavy fire disturbance, the CH4 was absorbed in spring and summer but emitted in autumn. The CO2 flux had a seasonal variation of summer > spring = autumn under no fire disturbance, but of summer > autumn > spring under fire disturbance; and the N2O flux varied in the order of spring > summer > autumn under no fire disturbance, but of autumn > spring > summer under slight fire disturbance, and of summer > spring = autumn under heavy fire disturbance. At unburned site, the CO2 flux was significantly positively correlated with air temperature and ground surface temperature; at slightly burned site, the CO2 flux had significant positive correlations with air temperature, 5-10 cm soil temperature, and water table; at heavily burned sites, there was a significant positive correlation between CO2 flux and 5-40 cm soil temperature. Fire disturbance made the CH4 emission increased by 169.5% at lightly burned site or turned into weak CH4 sink at heavily burned site, and made the CO2 and N2O emissions and the global warming potential (GWP) at burned sites decreased by 21.2% -34.7%, 65.6% -95.8%, and 22.9% -36.6% respectively, compared with those at unburned site. Therefore, fire disturbance

  5. Posttranslational modification of Birch and Ragweed allergen proteins by common gas phase pollutants, NO2 and O3

    Science.gov (United States)

    Mahmood, M. A.; Pope, F.; Bloss, W.

    2015-12-01

    The global incidence of hay fever has been rising for decades, however, the underlying reasons behind this rise remain unclear. It is hypothesized that exposure of pollen to common gas phase pollutants, such as nitrogen dioxide (NO2) and ozone (O3), increases the allergenicity of the pollen and thus increases hay fever incidence. Since atmospheric pollutants tend to have greater concentrations within urban areas (in particular NO2) the hypothesis suggests that greater allergenicity should occur in urban areas. Indeed, several studies do suggest higher hay fever incidence within urban areas compared to rural areas. Previous published work suggests a link between increased allergies with changes in the chemical composition of the pollen protein via posttranslational modification of the protein. This study investigates the posttranslational modification of two highly allergenic pollen species (Birch and Ragweed) that are common in Europe. Within the laboratory, we expose pollen grains to atmospherically relevant exposures of gas phase NO2, O3 and other common gas phase oxidants under a range of environmentally relevant conditions. The effects of the environmentally relevant exposures on the biochemistry of the pollen grains were probed using a proteomic approach (liquid chromatography coupled ultra-high resolution spectrometer). Our findings indicate the interaction between gas phase pollutants and pollen cause protein specific modifications; in particular, nitration occurs upon tyrosine residues and nitrosylation on cysteine residues. Possibly, these modifications may affect the immune response of the pollen protein, which may suggest a possible reason for increased allergies in reaction to such biologically altered protein. The laboratory-derived results will be supported with a time series analysis of asthma incidence rates for the London area, which take into account the pollen count, and pollutant concentrations. The implications of the results will be discussed

  6. Oocyst-Derived Extract of Toxoplasma Gondii Serves as Potent Immunomodulator in a Mouse Model of Birch Pollen Allergy.

    Directory of Open Access Journals (Sweden)

    Angelika Wagner

    Full Text Available Previously, we have shown that oral infection with Toxoplasma gondii oocysts prevented type I allergy in mice. Here we investigated whether the application of a T. gondii oocyst lysate antigen (OLA could also reduce allergy development. BALB/c mice were immunised twice with OLA followed by sensitisation with the major birch pollen (BP allergen Bet v 1 and an aerosol challenge with BP extract.First, we tested OLA in vitro. Stimulation of splenocytes and bone marrow-derived dendritic cells (BMDC with OLA led to the production of pro-inflammatory and regulatory cytokines such as IL-6, IFN-γ and IL-10. Moreover, BMDC exposed to OLA upregulated the maturation markers CD40, CD80, CD86, and MHCII. Furthermore, OLA was recognised by TLR2-transfected human embryonic kidney cells.Immunisation of mice with OLA induced high levels of Toxoplasma-specific IgG antibodies in sera along with increased production of IFN-γ and IL-10 in Toxoplasma-antigen restimulated splenocytes. OLA reduced allergic airway inflammation as manifested by significant reduction of eosinophils in bronchoalveolar fluids, decreased cellular infiltrates and mucus production in the lungs. Accordingly, Bet v 1-specific IgE was decreased in OLA-pretreated mice. The reduced allergic immune responses were accompanied by increased numbers of CD4+CD25highFoxp3+ regulatory T cells in spleens as well as by increased numbers of granulocytic myeloid-derived suppressor cells in lungs when compared to sensitised controls suggesting that these two cell populations might be involved in the suppression of the allergic immune responses.Our data demonstrate that pretreatment with the oocyst extract can exert anti-allergic effects comparable to T. gondii infection. Thus, the immunomodulatory properties of the parasite extract indicate that this extract and in the future defined molecules thereof might serve as immunomodulatory adjuvants in allergy treatment and prophylaxis.

  7. Physico-chemical comparison of betulinic acid, betulin and birch bark extract and in vitro investigation of their cytotoxic effects towards skin epidermoid carcinoma (A431), breast carcinoma (MCF7) and cervix adenocarcinoma (HeLa) cell lines.

    Science.gov (United States)

    Soica, Codruta M; Dehelean, Cristina A; Peev, Camelia; Aluas, Mihaela; Zupkó, I; Kása, P; Alexa, Ersilia

    2012-01-01

    Betulin and betulinic acid are pentacyclic triterpenes present in the bark of the birch tree and other vegetal sources. Quantitatively, in birch bark betulin is more significant than betulinic acid; therefore, birch can be a large and feasible source of raw material for betulin extraction. Betulin can be used as extracted or, after chemical modification, as a starting compound for its acid, betulinic acid, with both substances possessing various interesting pharmacological properties. The purpose of this study is to analyse the betulin and betulinic acid content of a birch tree bark extract, as well as its cytotoxic activity. The extraction was done using a Soxhlet extractor and chloroform/dichlormethane/methanol (1 : 1 : 1) as solvent. The betulin and betulinic acid content of the extract was estimated using standards of pure betulin and betulinic acid, by thermal analysis as opposed to pure substance (thermogravimetric and differential thermal analysis). The extract and the main compounds were also analysed by NMR. The results indicated a high amount of betulin in the final extract (up to 50%), and an important quantity of betulinic acid: over 3%. The cytotoxic activity indicated a high proliferation inhibition for the birch tree extract but was still comparable with betulinic acid and betulin.

  8. Root produced DHZR-, ZR- and IPA-like cytokinins in xylem sap in relation to coppice shoot initiation and growth in cloned trees of Betula pubescens.

    Science.gov (United States)

    Rinne, P; Saarelainen, A

    1994-10-01

    Six-year-old cloned Betula pubescens Ehrh. trees, grown outdoors at 65 degrees 01' N, were cut on six dates during the growing season to study coppice shoot development in relation to root-produced cytokinin-like compounds. Bleeding sap was collected over timed intervals for two days after cutting, and endogenous cytokinin-like compounds were measured by ELISA assay in HPLC-purified fractions of xylem sap. Initiation and development of coppice shoots on the clonally propagated plants were comparable to those in seedlings. Coppice shoot initiation was affected by the time of cutting, diminishing significantly after June. Of the cytokinin-like compounds detected in the xylem sap, zeatin riboside-like (ZR) compounds were present in the highest concentrations, and the concentrations of dihydrozeatin riboside-like (DHZR) and isopentenyladenoside-like (IPA) compounds were approximately one third and one eighth of the ZR concentrations, respectively. The concentration of cytokinin-like compounds was positively correlated with xylem sap flow rate. The export of cytokinin-like compounds, especially DHZR- and ZR-types, was positively correlated with the initiation and elongation rate of coppice shoots, the number of lateral branches, and the radial growth of the more slowly growing coppice shoots. The export of cytokinin-like compounds collected immediately after cutting may represent the basal value for each tree. This value is probably affected by the size and activity of the root system and may be a relevant estimate for predicting the success of coppicing.

  9. Contribution of Root Respiration to Total Soil Respiration in a Betula ermanii-Dark Coniferous Forest Ecotone of the Changbai Mountains, China

    Institute of Scientific and Technical Information of China (English)

    LIU Ying; HAN Shi-Jie; ZHOU Yu-Mei; ZHANG Jun-Hui

    2005-01-01

    Total and root-severed soil respiration rates for five plots set up 50 m apart in a Betula ermanii Cham.-dark coniferous forest ecotone on a north-facing slope of the Changbai Mountains, China, were measured to evaluate the seasonal variations of soil respiration, to assess the effect of soil temperature and water content on soil respiration, and to estimate the relative contributions of root respiration to the total soil respiration. PVC cylinders in each of 5 forest types of a B. ermanii-dark coniferous forest ecotone were used to measure soil respirations both inside and outside of the cylinders. The contribution of roots to the total soil respiration rates ranged from 12.5% to 54.6%. The mean contribution of roots for the different plots varied with the season, increasing from 32.5% on June 26 to 36.6% on August 3 and to 41.8% on October 14.In addition, there existed a significant (P < 0.01) logarithmic relationship between total soil respiration rate and soil temperature at 5 cm soil depth. Also, a similar trend was observed for the soil respiration and soil water content at the surface (0-5 cm) during the same period of time.

  10. The effect of exogenous sugar solution and high concentration of CO2 on the contents of sugar and protein of Betula platyphylla leaves

    Institute of Scientific and Technical Information of China (English)

    ZHOUYu-mei; YANGChuan-ping; WANGShu-juan; WUYue-liang; WANGWen-zhang

    2003-01-01

    The content of total sugar,sucrose,fructose and protein in the leaves of 3-yr.-old Betula platyphylla was measured after the treatment by three exogenous sugar solutions(sucrose,fructose,glucose) and three high concentrations of CO2(700,1400,2100μL·L-1) for about a month in 1998.The results showed that spraying three exogenous sugar solutions increased markedly the content of sugar and protein of leaves under 700μL·L-1 and 1400μL·L-1 CO2.The effect of spraying exogenous sucrose solution was the best among the three exogenous sugars.The treatment of spraying exogenous sugar solution and 2100μL·L-1 CO2 constrained the accumulation of total sugar and protein of leaves.There was no difference in protein content of leaves when spraying glucose and fructose solutions under 700μL·L-1 and 1400μL·L-1 CO2.The treatrnent of 2100μL·L-1 CO2 concentration significantly increased the contents of total sugar,sucrose,fructose,and protein of leaves compared with that of the 700μL·L-1 and 1400μL·L-1 CO2 except the plants spraying fructose solution.there was positive correlation between the content of sugar of leaves and CO2 concentration when spraying same exogenous sugar solution.

  11. Isolation of methyl syringate as a specific aflatoxin production inhibitor from the essential oil of Betula alba and aflatoxin production inhibitory activities of its related compounds.

    Science.gov (United States)

    Jermnak, Usuma; Yoshinari, Tomoya; Sugiyama, Yasumasa; Tsuyuki, Rie; Nagasawa, Hiromichi; Sakuda, Shohei

    2012-02-15

    Methyl syringate was isolated from the essential oil of Betula alba as an aflatoxin production inhibitor. It inhibited aflatoxin production of Aspergillus parasiticus and Aspergillus flavus with IC(50) values of 0.9 and 0.8 mM, respectively, without significantly inhibiting fungal growth. Methyl syringate reduced mRNA levels of genes (aflR, pksA, and omtB) [corrected] encoding proteins required for aflatoxin biosynthesis. Methyl gallate, methyl 3,4,5-trimethoxybenzoate, and methyl 3-O-methylgallate inhibited both aflatoxin production and fungal growth of A. parasiticus and A. flavus. However, their acids and syringic acid did not inhibit aflatoxin production and growth of A. parasiticus significantly, although gallic acid inhibited aflatoxin production of A. flavus with selectivity. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of methyl syringate was much weaker than that of gallic acid. These results showed that methyl syringate has a unique inhibitory activity toward aflatoxin production with a different mode of action from that of gallic acid.

  12. 白桦树皮提取物的降血脂作用研究%On Hypolipidemic Effects of White Birch Bark Extract

    Institute of Scientific and Technical Information of China (English)

    左红香; 郑光浩

    2012-01-01

    Objective To study hypolipidemic effects of white birch bark extract. Method The white birch bark extract (BH) at the dose of 300 mg/kg was given to mice in high-dose group,200 mg/kg in middle-dose group and 100 mg/kg in low-dose group, and Zhinbitieose at the dose of 300 mg/kg in the positive control group orally for 7 days for the prophylaxis of lipidemic disorders. At 2h after the final administration,75% egg yolk emulsion was intraperitoneally given to the mice in all groups except for the normal group to establish the mouse model of hyperlipidemia. Effects of BH at the different doses on lipid levels in blood in mice were measured at 12h after the modeling. Results The white birch bark extract could significantly reduce serum TC, TG and LDL-C contents, and significantly elevate HDL-C level. Conclusion The white birch bark extract can produce significantly hypolipidemic effect on mice.%目的研究白桦树皮提取物(BH)的降血脂作用.方法分正常组、模型组、BH给药组:高(300mg/kg)、中(200mg/kg)、低(100mg/kg)剂量和阳性对照组:脂必妥(300mg/kg).预防给药7d,末次给药2h后,腹腔注射75%蛋黄乳液制作小鼠高脂血症模型,造模12h后测定不同剂量的BH对小鼠血脂水平的影响.结果白桦树皮提取物能够显著降低小鼠血清中TC,TG,LDL-C浓度,显著升高HDL-C.结论白桦树皮提取物具有明显的降血脂作用.

  13. Allergic asthmatics show divergent lipid mediator profiles from healthy controls both at baseline and following birch pollen provocation.

    Directory of Open Access Journals (Sweden)

    Susanna L Lundström

    Full Text Available BACKGROUND: Asthma is a respiratory tract disorder characterized by airway hyper-reactivity and chronic inflammation. Allergic asthma is associated with the production of allergen-specific IgE and expansion of allergen-specific T-cell populations. Progression of allergic inflammation is driven by T-helper type 2 (Th2 mediators and is associated with alterations in the levels of lipid mediators. OBJECTIVES: Responses of the respiratory system to birch allergen provocation in allergic asthmatics were investigated. Eicosanoids and other oxylipins were quantified in the bronchoalveolar lumen to provide a measure of shifts in lipid mediators associated with allergen challenge in allergic asthmatics. METHODS: Eighty-seven lipid mediators representing the cyclooxygenase (COX, lipoxygenase (LOX and cytochrome P450 (CYP metabolic pathways were screened via LC-MS/MS following off-line extraction of bronchoalveolar lavage fluid (BALF. Multivariate statistics using OPLS were employed to interrogate acquired oxylipin data in combination with immunological markers. RESULTS: Thirty-two oxylipins were quantified, with baseline asthmatics possessing a different oxylipin profile relative to healthy individuals that became more distinct following allergen provocation. The most prominent differences included 15-LOX-derived ω-3 and ω-6 oxylipins. Shared-and-Unique-Structures (SUS-plot modeling showed a correlation (R(2 = 0.7 between OPLS models for baseline asthmatics (R(2Y[cum] = 0.87, Q(2[cum] = 0.51 and allergen-provoked asthmatics (R(2Y[cum] = 0.95, Q(2[cum] = 0.73, with the majority of quantified lipid mediators and cytokines contributing equally to both groups. Unique structures for allergen provocation included leukotrienes (LTB(4 and 6-trans-LTB(4, CYP-derivatives of linoleic acid (epoxides/diols, and IL-10. CONCLUSIONS: Differences in asthmatic relative to healthy profiles suggest a role for 15-LOX products of both ω-6 and ω-3 origin in allergic

  14. Phenogenetic response of silver birch populations and half-sib families to elevated ozone and ultraviolet-B radiation at juvenile age

    Energy Technology Data Exchange (ETDEWEB)

    Pliura, Alfas [Lithuanian Forest Research Institute, Department of Tree Genetics and Breeding, Liepu 1, Girionys LT-53101, Kaunas District (Lithuania); Lithuanian University of Agriculture, Studentu 13, LT-53361 Akademija, Kaunas District (Lithuania)], E-mail: genetsk@mi.lt; Baliuckiene, Asta [Lithuanian Forest Research Institute, Department of Tree Genetics and Breeding, Liepu 1, Girionys LT-53101, Kaunas District (Lithuania); Baliuckas, Virgilijus [Lithuanian Forest Research Institute, Department of Tree Genetics and Breeding, Liepu 1, Girionys LT-53101, Kaunas District (Lithuania); Lithuanian University of Agriculture, Studentu 13, LT-53361 Akademija, Kaunas District (Lithuania)

    2008-11-15

    Phenogenetic response of silver birch populations and half-sib families to separate and combined elevated ozone (O{sub 3}) concentrations and ultraviolet-B (UV-B) radiation dozes was studied at juvenile age in the climatic chambers. Significant population and family effects were found for seedling height, lamina width, and leaf damage. The exposure to UV-B radiation decreased genetic variation at the stage of seed germination. Complex exposure to UV-B and O{sub 3} caused an increase of genetic variation at the stage of intensive seedling growth: seedling height genetic variation in separate treatments increased from 23.7-38.6 to 33.7-65.7%, the increase for lamina width was from 10.2-13.9 to 13.6-31.8%. Different populations and families demonstrated differing response to elevated complex UV-B and O{sub 3} exposure. Changes of genetic intra-population variation were population-specific. Such changes in genetic variation under the impact of stressors can alter adaptation, stability, and competitive ability of regenerating populations in a hardly predictive way. - Exposure to elevated UV-B and O{sub 3} alters genetic variation of traits in progenies of silver birch populations.

  15. Stomatal uptake of O3 in aspen and aspen-birch forests under free-air CO2 and O3 enrichment.

    Science.gov (United States)

    Uddling, Johan; Hogg, Alan J; Teclaw, Ronald M; Carroll, Mary Anne; Ellsworth, David S

    2010-06-01

    Rising atmospheric carbon dioxide (CO2) may alleviate the toxicological impacts of concurrently rising tropospheric ozone (O3) during the present century if higher CO2 is accompanied by lower stomatal conductance (gs), as assumed by many models. We investigated how elevated concentrations of CO2 and O3, alone and in combination, affected the accumulated stomatal flux of O3 (AFst) by canopies and sun leaves in closed aspen and aspen-birch forests in the free-air CO2-O3 enrichment experiment near Rhinelander, Wisconsin. Stomatal conductance for O3 was derived from sap flux data and AFst was estimated either neglecting or accounting for the potential influence of non-stomatal leaf surface O3 deposition. Leaf-level AFst (AFst(l)) was not reduced by elevated CO2. Instead, there was a significant CO2 x O(3) interaction on AFst(l), as a consequence of lower values of gs in control plots and the combination treatment than in the two single-gas treatments. In addition, aspen leaves had higher AFst(l) than birch leaves, and estimates of AFst(l) were not very sensitive to non-stomatal leaf surface O3 deposition. Our results suggest that model projections of large CO2-induced reductions in gs alleviating the adverse effect of rising tropospheric O3 may not be reasonable for northern hardwood forests.

  16. Substrate Screening for Container Seedlings of Betula platyphylla%白桦容器育苗的适宜基质筛选

    Institute of Scientific and Technical Information of China (English)

    贾斌英; 徐惠德; 刘桂丰; 李开隆; 孙志虎; 彭红梅; 滕文华

    2009-01-01

    An experiment was conducted to screen the suitable substrate for container seedling cultivation in the green house of the Intensive Breeding Base of Betula platyphylla in Northeast Forestry University, Harbin City, Heilongjiang Province.The cultivation effects for different proportionings of peat, sand, and cultivated soil were analysed. Results showed that dif-ferent proportionings of peat, sand, and cultivated soil could significantly affect the relative content of chlorophyll, seedling height, basal diameter, and whole-plant biomass. As sand content was in the range of 0~20% , the chlorophyll content, seedling height, basal diameter, and whole-plant biomass reached their maximum values, while the above-mentioned indi-ces parabolically decreased with increasing percentage of sand. All the indices showed an increasing trend with increasing percentage of peat and a constant trend with increasing percentage of cultivated soil. Different proportionings of peat, sand, and cultivated soil could be classified into three groups according to the integrated analysis of relative chlorophyll content, basal diameter, seedling height, and whole-plant biomass. The optimum substrate proportion for cultivating con-tainer seedlings of B. platyphylla was screened out on the basis of economical and applicable principles, namely, the pro-portion of peat, sand, and cultivated soil was 2:1:7.%为了给东北地区白桦(Betula platyphylla Suk.)容器育苗提供适宜的基质配方,在东北林业大学白桦强化育种基地温室内,以河沙、草炭和耕作土为基质,对其18种配比的育苗结果进行了筛选.结果表明:3种基质的不同配比能够显著影响白桦苗木的SPAD值、苗高、地径和全株生物量.当河沙体积分数在0~20%的范围内,白桦苗木的SPAD值、苗高、地径和全株生物量处于最高值,随着基质中河沙比例的进一步增加,各指标呈抛物线下降;随着草炭比例的增加,各指标则呈现上升趋势;

  17. 长白山突变型林线岳桦对气候变化的响应%Climatic Response of Betula ermanii from Closed Treeline in Changbai Mountains

    Institute of Scientific and Technical Information of China (English)

    王晓东; 刘惠清

    2011-01-01

    在长白山北坡局地突变型林线内选取10个样方,采用实测法测量岳桦两种生活型(灌木状和乔木状)的树高、径级,采用年轮法测定岳桦的树龄,计算分析长白山北坡2000m处48 a(1953-2000年)的积温变化.对获得的数据采用回归模型、小波分析、相关分析建立树高、径级与积温变化的关系.结果显示:对应长白山48年来积温变化的几个高温期(1960年代初、1980年代、1990年代后期),岳桦树高生长对气候变化有显著响应.灌木状岳桦在径级1~7、7 ~13、13~19和>19 cm阶段树高生长分为适应期,弱胁迫期和胁迫期.乔木状岳桦在径级13 cm和5 cm出现增长受限和适宜生长两个拐点.高温期对应岳桦树高的快速生长,岳桦树高增长的年际变化是对气温变化的积极响应.%On the north slope of Changbai Mountain 10 quadrats were selected in local closed treeline. The tree height and size class of shrub and single tree Betula ermanii were obtained from field measured, and the tree age was determined by standard dendrochronological techniques. The relationship between the tree height and size class was established by means of the regression model against the collected data. The variation tendency of accumulated temperature in the past 48 years on the 2 000 m high of the northern slope on Changbai Mountains was also calculated through the wavelet analysis method. The relationship between the tree height and accumulated temperature was established by means of multiple correlation analysis against the collected data. The results show that the tree height and size class have significant response against the high temperature period in the past 48 years on Changbai Mountains, including the beginning of 1960s, and late 1980s and 1990s. The tree height growth for shrub Betula ermanii is divided into adaptive phase, low stress phase and high stress phase according to its size class of 1 ~ 7, 7 -13, 13 ~ 19 and larger than

  18. Study on Growth Volume of Different Provenances of Betula alnoides Plantation%不同种源西南桦人工林生长量研究

    Institute of Scientific and Technical Information of China (English)

    袁莲珍; 史富强; 许林红; 刘际梅

    2012-01-01

    Using Excel and DPS data software Duncan multiple comparisons, the DBH, tree height and volume of 25 provenances of Betula alnoides in Puwen Experimental Farm were analyzed, results showed that: DBH, tree height and growth volume of five years different provenances Belula alnoides had the remarkable difference, the growth curve of two years tended to be linear, growth curve of four years and five years tended to be waveform: Provenance E (Tianyang of Guangxi province) had the largest growth volume, the next is provenance K (Lancang of Yunnan) : and in the four years, the smallest is the provenance A ( Linyun of Cuangxi) : in the five years, the smallest is the provenance J ( Mojiang of Yunnan).%对普文试验林场的25个不同种源西南桦子测林测定胸径、树高、材积等生长性状,利用Excel和DPS数据软件Duncan进行数据分析.结果表明:不同种源西南桦5a生时胸径、树高和材积存在着显著差异,生长曲线在2 a生时近趋于直线;在4 a生和5 a生时生长曲线呈波形;生长量最大的是种源E(广西田阳),其次是种源K(云南澜沧);4 a生时生长量最小的是种源A(广西凌云),5a生时生长量最小的是种源J(云南墨江).

  19. 高温热处理对西南桦材色的影响%Impact of Heat Treatment on Color of Betula alnodies Wood

    Institute of Scientific and Technical Information of China (English)

    陈太安; 王昌命; 曾金水; 汉丽辉; 付成方

    2012-01-01

    Taking mass loss as the intensity damage indictor after the heat treatment was applied to the wood, the impact of heat treatment on the color of Betula alnodies wood was studied, and the correlation analysis between the mass loss and color change was conducted. It was showed that the lightness of the wood was decreased, whereas the color difference was increased along with the increment of treating temperature and treating time duration. There was no distinct rule for the change of the color parameters L * , a * , and b * determined by the CIELAB method. The mass loss was increased with prolonging of the heat treatment, which might be applied as a right index to indicate the lightness change and color difference before and after the heat treatment.%以失重率作为木材高温处理的强度损失因子,研究热处理对西南桦材色的影响,并对失重率与材色变化进行关联分析.结果表明:西南桦木材的明度、色差随处理温度的上升和处理时间的延长而下降、增加,红绿度和黄蓝度变化规律不明显;失重率随处理温度的上升和处理时间的延长而增加,以其为处理强度损失因子对明度变化和处理前后试材色差具有良好的指示性.

  20. Diarylheptanoids from leaves of Betula platyphylla%白桦叶中的二苯基庚烷类化合物

    Institute of Scientific and Technical Information of China (English)

    王素娟; 裴月湖

    2001-01-01

    目的对白桦叶的化学成分做系统研究,以更好的开发利用我国的植物资源。方法采用硅胶柱、凝胶柱及制备薄层色谱法进行分离,通过波谱技术(1HNMR,13CNMR,1H-1HCOSY,HMQC,HMBC,NOESY)进行结构鉴定。结果分离鉴定了4种二苯基庚烷类化合物,槭木素丁(Ⅰ),氧杂二苯庚烯(Ⅱ),17-甲基-15-甲氧基-7-氧代槭木素丁(Ⅲ),槭木素十一(Ⅳ)。结论化合物Ⅲ,Ⅳ均首次从本种植物中分离得到,并纠正了化合物Ⅲ的碳谱数据归属。%Object To study the chemical consti tuents of Betula platyphyllaSuk. for the better deve-lopmen t an d utilization of botanic resources of our country. Methods The constituents were isolated by column chromatography (silica gel and Sephadex LH 20) and preparative TLC, and identified by means of spectral data (1HNMR, 13CNMR, 1H-1HCOSY, HMQC, HMBC, NOESY). Resu lts 4 diarylheptanoids were obtained and elucidated as acerogenin E (Ⅰ ), (3R)-3, 5′-dihydroxy-4′-methoxy-3′, 4″-oxo-l, 7-diphenyl-l-hep te ne (Ⅱ), 15-methoxy-17-O-methyl-7-oxoacerogenin E (Ⅲ), ac erogenin K (Ⅳ). Conclusion Compounds Ⅲ and Ⅳ were isolated for the first time from this plant and the assignment of 13CNMR data o f compound Ⅲ was corrected.

  1. [Allelopathic effects of the humus soils from Betula platyphylla and Quercus liaotungensis pure plantations on 9 kinds of common shrubs and herbs].

    Science.gov (United States)

    Huang, Liang-Jia; Liu, Zeng-wen; Zhu, Bo-Chao; Bing, Yuan-Hao; Zhang, Xiao-Xi; Lü, Chen

    2014-06-01

    The humus soils were collected from Betula platyphylla and Quercus liaotungensis pure plantations and woodless land separately where the site conditions were basically the same, and taken as medium for potting culture test of 9 kinds of shrubs or herbs in plastic greenhouse to assess the allelopathic effects of humus soils of pure plantations on shrubs or herbs. Humus soils from B. platyphylla plantation significantly inhibited the seed germinations of Medicago sativa and Melilotus officinalis, decreased the catalase (CAT) activity of M. officinalis, Coronilla varia, M. sativa and Lespedeza davurica, and improved malondialdehyde (MDA) contents in seedlings of Caragana kor-shinskii, C. varia and Astragalus adsurgens. The biomass growths of C. varia, Amorpha fruticosa, M. sativa, M. officinalis and A. adsurgens in humus soils from B. platyphylla plantation were significantly decreased by 48.2%, 45.1%, 44.3%, 37.3% and 36.0%, respectively. In addition, humus soil of Q. liaotungensis plantation significantly decreased the germination rates of M. sativa and A. adsurgens, the chlorophyll contents of Vicia villosa, A. fruticosa and M. sativa, and improved malondialdehyde (MDA) contents in seedlings of Lespedeza davurica, Caragana korshinskii, M. officinalis and A. adsurgens. The biomass growths of A. adsurgens, M. sativa, M. officinalis and A. fruticosa were significantly decreased by 52.6% , 43.8%, 35.5% and 34.6%, respective- ly. B. platyphylla plantation humus soil had obvious inhibition effects on M. sativa, M. officinalis and A. fruticosa, while Q. liaotungensis plantation humus soil had obvious inhibition effects on M. sativa, A. adsurgens and A. fruticosa.

  2. A randomized DBPC trial to determine the optimal effective and safe dose of a SLIT-birch pollen extract for the treatment of allergic rhinitis : results of a phase II study

    NARCIS (Netherlands)

    Pfaar, O.; van Twuijver, E.; Boot, J. D.; Opstelten, D. J. E.; Klimek, L.; van Ree, R.; Diamant, Z.; Kuna, P.; Panzner, P.

    2016-01-01

    Background: Sublingual immunotherapy (SLIT) is a potential efficacious and safe treatment option for patients with respiratory, IgE-mediated allergic diseases. A combined tolerability, dose-finding study with a sublingual liquid birch pollen preparation (SB) was conducted. Methods: Two hundred and s

  3. Vaccination for birch pollen allergy. Induction of affinity-matured or blocking IgG antibodies does not account for the reduced binding of IgE to Bet v 1

    DEFF Research Database (Denmark)

    Svenson, Morten; Jacobi, Henrik H; Bødtger, Uffe;

    2003-01-01

    Specific allergy vaccination (SAV) is associated with increased levels of allergen specific IgG in serum. It is not clear, however, to what extent qualitative changes in allergen binding to IgG may be induced as well. We therefore analyzed the binding of the major allergen in pollen of birch...

  4. [Expression analysis of miR164 and its target gene NAC1 in response to low nitrate availability in Betula luminifera].

    Science.gov (United States)

    Jun, Wu; Junhong, Zhang; Menghui, Huang; Minhui, Zhu; Zaikang, Tong

    2016-02-01

    Nitrogen, an essential macronutrient for the growth and development of plants, affects above- ground biomass accumulation dramatically. Thus, it is very important to reveal the molecular mechanisms of how plants resist or adapt to low nitrogen availability. The NAC1(NAM, ATAF, CUC 1) gene, located in the upstream regulatory network, has been reported to resist low nitrogen by regulating expression of key downstream genes and thus root growth in (Populus tremula × alba).In this study, we detected the responses of miR164 and its target gene NAC1 under nitrate-starvation condition using the Betula luminifera somaclones G49-3 as material. The NAC1 gene which contains 1497 bp sequence, encodes 358 amino acids and contains a highly conserved NAM domain at N terminal was cloned by the RACE method. The NAC1 was then validated to be the target gene of miR164 via 5'-RACE, and the cleavage site was between the 10(th) and 11(th) base. The expression patterns of miR164 and its target gene NAC1 were further detected under nitrate-starvation condition through qRT-PCR analysis. The results showed that miR164 expression was repressed by nitrate-starvation at the beginning of the treatment (4 d) and then ascended. However, the expression pattern of miR164 in roots was different from that in shoots and leaves. Moreover, the expression levels of target gene NAC1 and miR164 were negatively correlated. The expression level of miR164 in root was increased while that of NAC1 was decreased under Re treatment, which indicated that miR164 and its target gene NAC1 play a regulatory role in response to low nitrate availability. The findings of our study may help elucidate the molecular mechanisms by which miR164 regulates target gene NAC1 at post-transcriptional level, and provide valuable information for further study of the regulatory roles of miR164-NAC1 under nitrate-starvation condition.

  5. Modelling tree biomasses in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Repola, J.

    2013-06-01

    Biomass equations for above- and below-ground tree components of Scots pine (Pinus sylvestris L), Norway spruce (Picea abies [L.] Karst) and birch (Betula pendula Roth and Betula pubescens Ehrh.) were compiled using empirical material from a total of 102 stands. These stands (44 Scots pine, 34 Norway spruce and 24 birch stands) were located mainly on mineral soil sites representing a large part of Finland. The biomass models were based on data measured from 1648 sample trees, comprising 908 pine, 613 spruce and 127 birch trees. Biomass equations were derived for the total above-ground biomass and for the individual tree components: stem wood, stem bark, living and dead branches, needles, stump, and roots, as dependent variables. Three multivariate models with different numbers of independent variables for above-ground biomass and one for below-ground biomass were constructed. Variables that are normally measured in forest inventories were used as independent variables. The simplest model formulations, multivariate models (1) were mainly based on tree diameter and height as independent variables. In more elaborated multivariate models, (2) and (3), additional commonly measured tree variables such as age, crown length, bark thickness and radial growth rate were added. Tree biomass modelling includes consecutive phases, which cause unreliability in the prediction of biomass. First, biomasses of sample trees should be determined reliably to decrease the statistical errors caused by sub-sampling. In this study, methods to improve the accuracy of stem biomass estimates of the sample trees were developed. In addition, the reliability of the method applied to estimate sample-tree crown biomass was tested, and no systematic error was detected. Second, the whole information content of data should be utilized in order to achieve reliable parameter estimates and applicable and flexible model structure. In the modelling approach, the basic assumption was that the biomasses of

  6. Tree species composition affects the abundance of rowan (Sorbus aucuparia L.) in urban forests in Finland.

    Science.gov (United States)

    Hamberg, Leena; Lehvävirta, Susanna; Kotze, D Johan; Heikkinen, Juha

    2015-03-15

    Recent studies have shown a considerable increase in the abundance of rowan (Sorbus aucuparia) saplings in urban forests in Finland, yet the reasons for this increase are not well understood. Here we investigated whether canopy cover or tree species composition, i.e., the basal areas of different tree species in Norway spruce dominated urban forests, affects the abundances of rowan seedlings, saplings and trees. Altogether 24 urban forest patches were investigated. We sampled the number of rowan and other saplings, and calculated the basal areas of trees. We showed that rowan abundance was affected by tree species composition. The basal area of rowan trees (≥ 5 cm in diameter at breast height, dbh) decreased with increasing basal area of Norway spruce, while the cover of rowan seedlings increased with an increase in Norway spruce basal area. However, a decrease in the abundance of birch (Betula pendula) and an increase in the broad-leaved tree group (Acer platanoides, Alnus glutinosa, Alnus incana, Amelanchier spicata, Prunus padus, Quercus robur, Rhamnus frangula and Salix caprea) coincided with a decreasing number of rowans. Furthermore, rowan saplings were scarce in the vicinity of mature rowan trees. Although it seems that tree species composition has an effect on rowan, the relationship between rowan saplings and mature trees is complex, and therefore we conclude that regulating tree species composition is not an easy way to keep rowan thickets under control in urban forests in Finland.

  7. Reaction of Leaf Weevil Phyllobius arborator (Coleoptera: Curculionidae) to Manganese Content in Diet.

    Science.gov (United States)

    Martinek, P; Kula, E; Hedbávný, J

    2016-12-27

    Reaction of leaf weevil (Phyllobius arborator (Herbst)) to increased concentration of manganese in diet was investigated in laboratory rearing with controlled temperature, humidity, and light conditions. Food for leaf weevils in rearing (leaves of birch Betula pendula Roth) was contaminated by soaking the leaves in solutions of MnCl24H2O with graded concentration of manganese. Direct influence of food was characterized by the consumed amount of leaves, period of feeding, and weight of P. arborator adults. At the same time, the levels of manganese in unconsumed food, excrement, and bodies of adults were determined.Even very high content of manganese in food did not cause significantly different reaction of P. arborator adults in comparison to individuals in control treatment. No significant difference in the quantity of the consumed food, weight of adults, and duration of their feeding period was found between the treatments within the experiment. The content of manganese found in food, excrement, and adult beetles indicate that P. arborator avoided manganese intoxication through food by both-voiding manganese through the feces and sequestering it at relatively high concentrations in unspecified parts of their body.

  8. Stem CO2 release under illumination: corticular photosynthesis, photorespiration or inhibition of mitochondrial respiration?

    Science.gov (United States)

    Wittmann, Christiane; Pfanz, Hardy; Loreto, Francesco; Centritto, Mauro; Pietrini, Fabrizio; Alessio, Giorgio

    2006-06-01

    In illuminated stems and branches, CO2 release is often reduced. Many light-triggered processes are thought to contribute to this reduction, namely photorespiration, corticular photosynthesis or even an inhibition of mitochondrial respiration. In this study, we investigated these processes with the objective to discriminate their influence to the overall reduction of branch CO2 release in the light. CO2 gas-exchange measurements of young birch (Betula pendula Roth.) branches (photorespiration does not play a pre-dominant role in carbon exchange. This suppression of photorespiration was attributed to the high CO2 concentrations (C(i)) within the bark tissues (1544 +/- 227 and 618 +/- 43 micromol CO2 mol(-1) in the dark and in the light, respectively). Changes in xylem CO2 were not likely to explain the observed decrease in stem CO2 release as gas-exchange measurements before and after cutting of the branches did not effect CO2 efflux to the atmosphere. Combined fluorescence and gas-exchange measurements provided evidence that the light-dependent reduction in CO2 release can pre-dominantly be attributed to corticular refixation, whereas an inhibition of mitochondrial respiration in the light is unlikely to occur. Corticular photosynthesis was able to refix up to 97% of the CO2 produced by branch respiration, although it rarely led to a positive net photosynthetic rate.

  9. Asynchrony between Host Plant and Insects-Defoliator within a Tritrophic System: The Role of Herbivore Innate Immunity.

    Directory of Open Access Journals (Sweden)

    Vyacheslav V Martemyanov

    Full Text Available The effects of asynchrony in the phenology of spring-feeding insect-defoliators and their host plants on insects' fitness, as well as the importance of this effect for the population dynamics of outbreaking species of insects, is a widespread and well-documented phenomenon. However, the spreading of this phenomenon through the food chain, and especially those mechanisms operating this spreading, are still unclear. In this paper, we study the effect of seasonally declined leafquality (estimated in terms of phenolics and nitrogen content on herbivore fitness, immune parameters and resistance against pathogen by using the silver birch Betula pendula--gypsy moth Lymantria dispar--nucleopolyhedrovirus as the tritrophic system. We show that a phenological mismatch induced by the delay in the emergence of gypsy moth larvae and following feeding on mature leaves has negative effects on the female pupal weight, on the rate of larval development and on the activity of phenoloxidase in the plasma of haemolymph. In addition, the larval susceptibility to exogenous nucleopolyhydrovirus infection as well as covert virus activation were both enhanced due to the phenological mismatch. The observed effects of phenological mismatch on insect-baculovirus interaction may partially explain the strong and fast fluctuations in the population dynamics of the gypsy moth that is often observed in the studied part of the defoliator area. This study also reveals some indirect mechanisms of effect related to host plant quality, which operate through the insect innate immune status and affect resistance to both exogenous and endogenous virus.

  10. The efficacy of six elite isolates of the fungus Chondrostereum purpureum against the sprouting of European aspen.

    Science.gov (United States)

    Hamberg, Leena; Hantula, Jarkko

    2016-04-15

    The sprouting of broad-leaved trees after cutting is problematic in forest regeneration areas, along roads and railways, under electric power and above gas pipe lines. In Finland, one of the most difficult species to control in these areas is the European aspen (Populus tremula), which produces both stump sprouts and root suckers after saplings have been cut. In this study, we investigated whether a decay fungus of broad-leaved trees, Chondrostereum purpureum, could be used as a biological control agent against aspen sprouting. The efficacy of six elite strains of C. purpureum (improved earlier in a breeding process) was investigated on aspen for three years. The most efficient C. purpureum strain, R53, tested earlier on birch (Betula pendula and B. pubescens), was efficient in causing mortality of aspen stumps and preventing the development of root suckers. With this strain, stump mortality was 78%, while significantly lower in control stumps which were cut only (47%). Aspen trees in the vicinity of the treatments (within a 10 m radius around each sapling) decreased the efficacy of C. purpureum. This study shows that the decay fungus C. purpureum can successfully be used in the sprout control of aspen saplings.

  11. Moss mites (Acari: Oribatida in soil revitalizing: a chance for practical application in silviculture

    Directory of Open Access Journals (Sweden)

    Klimek Andrzej

    2014-12-01

    Full Text Available The Oribatida (known as moss mites or beetle mites increase the breakdown of organic material in the soil. The paper analyses the dynamics of their abundance and number of species after various treatments enriching the soil in 4 study areas: afforested post-agricultural area in the Tuchola Forest, afforested degraded post-military training area in Bydgoszcz-Jachcice, and forest nurseries at Białe Błota and Bielawy. The results show that in post-agricultural and degraded soils at the initial stages of forest succession, the density and number of species of oribatid mites were low, even after phyto-land-improvement (afforestation and lupin as green manure. In the forest nurseries, however, we recorded a positive effect of soil revitalizing after mulching with forest ectohumus (i.e. organic surface layer of the soil. The inoculation of soils with forest mesofauna appeared more effective in nursery plantations of silver birch (Betula pendula and small-leaved lime (Tilia cordata, as compared with Scots pine (Pinus sylvestris. Thus to revitalize degraded soils effectively and to accelerate forest succession, apart from phytoland- improvement, it is advisable also to reintroduce mesofauna, e.g. with the use of forest ectohumus.

  12. Leaching of nitrogen and phosphorus during production of forest seedlings in containers.

    Science.gov (United States)

    Juntunen, Marja-Liisa; Hammar, Taina; Rikala, Risto

    2002-01-01

    Little information is available concerning the contamination risk caused by forest seedling nurseries to local surface and ground waters compared with agricultural and horticultural production. Leaching of nitrogen (N) and phosphorus (P) through peat growing medium in containers and nutrient uptake of seedlings were monitored in production of silver birch (Betula pendula Roth), Norway spruce [Picea abies (L.) Karst], and Scots pine (Pinus sylvestris L.) seedlings. About half of the applied nutrients (total amount applied = 149 to 260 kg N ha(-1) and 60 to 108 kg P ha(-1)) was premixed into the peat medium, as is usual in Finnish nursery practice, and the other half was applied to seedlings in liquid form with mobile booms. Depending on tree species, 11 to 19% of the applied N was recovered in leachates and 15 to 63% in seedlings. The undiscovered proportion varied from 19 to 71%. The amounts of leached N were 19 to 41 kg ha(-1). Only 5 to 31% of the applied P was recovered in seedlings; 16 to 64% (11 to 56 kg ha(-1)) was found in leachates. Total N and P load to the environment may increase substantially if nutrients applied in liquid fertilization outside container trays are included. Consequently, it is important to determine the sources of nutrient load in container seedling production to mitigate the risk of environment contamination.

  13. The amount of carbon in the undergrowth biomass of main types of forests stands in Poland

    Directory of Open Access Journals (Sweden)

    Janyszek Sławomir

    2015-12-01

    Full Text Available The sequestration of carbon in biomass of herb and moss layers of forest ecosystems is relatively less studied, than analogical processes in trees biomass and soil organic mass. The paper presents mean values of carbon concentration and mean amounts of dry mass of plant material in the herb and moss layer of phytocoenoses formed under canopy of stands of main forest-forming species of trees in Poland. The parameters were studied for beech, birch, oak, alder, pine, fir and spruce forest stands, for most of the particular age classes. The studied plots were contained in following plant associations and communities: Ribo nigri-Alnetum, Fraxino-Alnetum, Galio odorati-Fagetum, Luzulo luzuloidis-Fagetum, Molinio caeruleae-Quercetum roboris, Calamagrostio-Quercetum petraeae, Abietetum polonicum, Abieti-Piceetum montanum, Calamagrostio villosae-Piceetum, as well as anthropogenic communities: Betula pendula comm. on Leucobryo-Pinetum habitat, Larix decidua comm. on Tilio-Carpinetum habitat, Pinus sylvestris comm. on Tilio-Carpinetum habitat, Picea abies comm. on Luzulo pilosae-Fagetum habitat (in lowland and Picea abies comm. on Luzulo luzuloidis-Fagetum habitat (in lower mountain localities. The relatively highest carbon amount was observed in oak forests, pine forests and in older age classes of lowland beech forest, where the carbon concentration in dry mass reaches from 60 to 81%. The lowest concentrations were determined for lowland spruce forests, highland fir forests and for alder forests. The carbon concentration reached in these types of ecosystems from 39 to 41%.

  14. Screening Analyses of Pinosylvin Stilbenes, Resin Acids and Lignans in Norwegian Conifers

    Directory of Open Access Journals (Sweden)

    Anne Fiksdahl

    2006-01-01

    Full Text Available The content and distribution of stilbenes and resin acids in Scots pine (Pinus sylvestris and spruce (Picea abies, sampled in central Norway, have been examined. The contents of pinosylvin stilbenes in pine heartwood/living knots were 0.2-2/2-8 % (w/w. No stilbenes could be detected in spruce (Picea abies. The resin acid contents of pine sapwood/heartwood and knots were 1-4 and 5-10 % (w/w, respectively. Minor amounts of resin acids (< 0.2/< 0.04 %w/w were identified in spruce wood/knots. The lignan content in knots of Norwegian spruce was 6.5 % (w/w. Diastereomerically pure hydroxymatairesinol (HMR, 84 % of total lignans was readily isolated from this source since only minor quantities (2.6 % of total lignans of the allo-HMR diastereomer was detected. Insignificant amounts of lignans were present in the sapwood. Lignans could not be detected in the sapwood or knots of Norwegian sallow (Salix caprea, birch (Betula pendula or juniper (Juniperus communis.

  15. Ethyl lactate-EDTA composite system enhances the remediation of the cadmium-contaminated soil by autochthonous willow (Salix x aureo-pendula CL 'J1011') in the lower reaches of the Yangtze River.

    Science.gov (United States)

    Li, Jiahua; Sun, Yuanyuan; Yin, Ying; Ji, Rong; Wu, Jichun; Wang, Xiaorong; Guo, Hongyan

    2010-09-15

    In order to explore a practical approach to the remediation of the cadmium (Cd)-contaminated soil in the lower reaches of the Yangtze River, we evaluated the effects of a local willow (Salix x aureo-pendula CL 'J1011') of absorbing, accumulating, and translocating Cd; and assessed the potential of chelator ethylenediaminetetraacetic acid (EDTA) in combination with ethyl lactate for enhancing the efficiency of the willow in removing Cd in two water-culture growth chamber trials and a field one. The willow showed a high tolerance to Cd in growth chamber trial 1 where the Cd concentration in the medium reached up to 25 mg L(-1) medium, and the bioaccumulation factors (BAFs) of the shoots for Cd rose from 3.8 to 7.4 as the Cd concentration in the medium was elevated from 5 to 25 mg L(-1) medium. In growth chamber trial 2, the average Cd removal rates in two treatments with EDTA and ethyl lactate (molar ratios of EDTA to ethyl lactate=68/39 and 53.5/53.5, respectively) reached 0.71 mg d(-1) pot(-1) for the duration of Day 5-8 and 0.59 mg d(-1) pot(-1) for that of Day 8-11, which were 5- and 4-fold of their counterparts in the control, respectively. In the field trial, for the remediational duration of 45 days, three treatments-willow alone, willow combined with EDTA, and willow combined with EDTA and ethyl lactate-led to decreases in the Cd concentration in soil by 5%, 20%, and 29%, respectively; increases in that in the leaves by 14.6%, 56.7%, and 146.5%, respectively; and increases in that in the stems by 15.6%, 41.2%, and 87.4%, respectively, compared to their counterparts on Day 0. These results indicate that EDTA combined with ethyl lactate significantly enhanced the efficiency of willow in removing Cd from the soil. Therefore, a phytoextration system consisting of the autochthonous willow, EDTA, and ethyl lactate has high potential for the remediation of the Cd-polluted soil in the lower reaches of the Yangtze River.

  16. Late glacial multiproxy evidence of vegetation development and environmental change at Solova, southeastern Estonia

    Directory of Open Access Journals (Sweden)

    Amon, Leeli

    2010-06-01

    Full Text Available Reinvestigation of the late glacial Solova (Remmeski basin, based on plant macro­fossil and diatom record, AMS 14C chronology and sediment composition (loss-on-ignition and magnetic susceptibility data, provided information on vegetation history and palaeoenvironmental and palaeoclimatic changes since the time of the deglaciation of the area around 14 000 cal yr BP. The chronology of the sequence is based on seven AMS dates on terrestrial macrofossils, providing evidence of rapid sedimentation in between 14 000 and 13 500 cal yr BP. Loss-on-ignition data show a clear short-lived warming episode centred to 13 800 cal yr BP, tentatively correlated with the GI-1c warming of the event stratigraphy of the Last Termination in the North Atlantic region, which suggests that at least parts of the Haanja Heights were ice-free by 14 000 cal yr BP. Macrofossil evidence indicates Betula nana–Dryas octopetala-dominated open tundra communities with Saxifraga on dry ground, and Carex sp. and Juncus on wet ground at that time. The first evidence of the postglacial presence of tree birch (Betula pendula in Estonia is dated back to 13 500 cal yr BP. However, conifer remains were not found in the late glacial sediment sequence of Solova Bog. The late-Allerød (GI-1a organic deposits, which are quite typical of other parts of Estonia and indicate general warming, are missing at Solova, most probably due to a hiatus in sedimentation in this very small and shallow upland basin.

  17. Soil Seed Bank Characteristics Preliminary Comparison between Plantation and Natural Forest of Betula alnoides%西南桦人工林与天然林土壤种子库特征初步比较

    Institute of Scientific and Technical Information of China (English)

    陈勇; 刘海姣; 张劲峰; 耿云芬

    2013-01-01

    以西南桦人工林与天然林的土壤种子库为研究对象,采用室内萌发法对云南热区的西南桦人工林与天然林下0 ~10 cm深度的土壤种子库的种子储量及其垂直分布进行了研究.研究结果表明:①西南桦人工林有活力种子储量为2 027粒/m2,天然林有活力种子储量为3 043粒/m2;②西南桦人工林土壤种子库由21科38属的42种植物组成,其中乔木4种,占全部种类的0.69%;灌木16种,占7.70%;多年生草本10种,占14.90%;1 a生草本9种,占73.36%;藤本3种,占3.35%.西南桦天然林土壤种子库由24科43属的49种植物组成,其中乔木6种,占全部种类的10.56%;灌木15种,占18.31%;多年生草本14种,占4.38%;1 a生草本10种,占65.06%;藤本4种,占1.69%;③乔木、灌木的植物数量占总数的比例为天然林>人工林,而草本和藤本为天然林<人工林;④西南桦人工林与天然林土壤种子库有活力种子密度自上而下都呈现下降趋势,0~5 cm种子数量较5 ~ 10 cm多.%Taking soil seed bank of Betula alnoides plantation and Betula alnoides natural forest as the object, seeds storage and vertical distribution of soil seed bank under depth of 0 ~ 10cm were studied in Yunnan hot zone by using indoor germination method. The results showed that; (1)Vigor seed reserves of Betula alnoides plantation was 2027 seeds/ m2, and natural forest was 3043 seeds/ m2; (2) Soil seed bank of Betula alnoides plantation was consisted of 42 plant species belonging to 21 family and 38 genus, including 4 kinds of Arbor species, accounting for 0. 69% of all species; 16 kinds of shrubs, accounting for 7. 70% ; 10 kinds of perennial herbs, accounting for 14. 90% ; 9 kinds of annual herb, accounting for 73. 36% ; 3 kinds of Fujimoto, accounting for 3. 35% . Soil bank of Betula alnoides natural forest was consisted of 49 plant species belonging to 24 family and 43 genus, including 6 kinds of trees, accounting for

  18. Changes in petiole hydraulic properties and leaf water flow in birch and oak saplings in a CO{sub 2}-enriched atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, N.; Morii, N.; Koike, T. [Hokkaido Univ., Sapporo (Japan). Graduate School of Agriculture; Ueda, T. [Hokkaido DALTON, Sapporo (Japan); Funada, R. [Tokyo Univ. of Agriculture and Technology, Tokyo (Japan). Faculty of Agriculture; Takagi, K.; Hiura, T.; Sasa, K. [Hokkaido Univ., Sapporo (Japan). Forests, Field Science Center for Northern Biosphere

    2008-02-15

    This study examined the water flow and petiole hydraulic properties in the individual leaves of Betula maximowicziana Regel and ring-porous Quercus mongolica Fish. ex Ledeb ssp. crispula Menitsky. The aim of the study was to examine the relationship between water flow, hydraulic properties and elevated carbon dioxide (CO2). The effects of elevated CO{sub 2} on sun and shade leaves of 2 petioles were investigated in order to examine structural changes in response to CO{sub 2}. The study was conducted at the Sapporo Experimental Forest in Japan, where a free air CO{sub 2} enrichment system was used to maintain CO{sub 2} levels. Results of the study demonstrated that elevated CO{sub 2} levels consistently decreased water flow, including leaf-specific hydraulic conductivity and total vessel area of the petiole in leaves exposed to the sun. Elevated CO{sub 2} levels had no impact on the hydraulic conductivity of shade leaves. It was concluded that changes in water flow were also associated with changes in petiole hydraulic properties. 57 refs., 2 tabs., 4 figs.

  19. Four Novel Cellulose Synthase (CESA Genes from Birch (Betula platyphylla Suk. Involved in Primary and Secondary Cell Wall Biosynthesis

    Directory of Open Access Journals (Sweden)

    Xuemei Liu

    2012-09-01

    Full Text Available Cellulose synthase (CESA, which is an essential catalyst for the generation of plant cell wall biomass, is mainly encoded by the CesA gene family that contains ten or more members. In this study; four full-length cDNAs encoding CESA were isolated from Betula platyphylla Suk., which is an important timber species, using RT-PCR combined with the RACE method and were named as BplCesA3, −4, −7 and −8. These deduced CESAs contained the same typical domains and regions as their Arabidopsis homologs. The cDNA lengths differed among these four genes, as did the locations of the various protein domains inferred from the deduced amino acid sequences, which shared amino acid sequence identities ranging from only 63.8% to 70.5%. Real-time RT-PCR showed that all four BplCesAs were expressed at different levels in diverse tissues. Results indicated that BplCESA8 might be involved in secondary cell wall biosynthesis and floral development. BplCESA3 appeared in a unique expression pattern and was possibly involved in primary cell wall biosynthesis and seed development; it might also be related to the homogalacturonan synthesis. BplCESA7 and BplCESA4 may be related to the formation of a cellulose synthase complex and participate mainly in secondary cell wall biosynthesis. The extremely low expression abundance of the four BplCESAs in mature pollen suggested very little involvement of them in mature pollen formation in Betula. The distinct expression pattern of the four BplCesAs suggested they might participate in developments of various tissues and that they are possibly controlled by distinct mechanisms in Betula.

  20. The Analysis of the Growing Process of Choerospondias Axillaris,Alnus and Betula Luminifera%南酸枣、桤木、光皮桦生长发育进程研究

    Institute of Scientific and Technical Information of China (English)

    张文鸿

    2015-01-01

    对腾冲县苏江林场于2012年春季在杉木采伐迹地上采用南酸枣、桤木、光皮桦与萌生杉木营造混交林,3年生时进行了调查并分析。结果表明:造林3年后3个树种的幼林保存率均达到92%,南酸枣、桤木、光皮桦阔叶树种的早期生长均表现了较强的速生性,各树种平均树高和胸径依次为南酸枣6.0m 和6.5cm ,桤木5.8m和6.2cm ;光皮桦4.8m和4.4cm。南酸枣更适宜作为腾冲杉木采伐迹地的更新树种,营造速生丰产的工业原料林。%A mixed forest w hich contains Choerospondias axillaris ,Alnus ,Betula luminifera and the coppice of Chinese fir was built on the cutover land of Chinese fir in Sujiang Forestry Centre in the spring of 2012 .The article conducts an investigation and analysis of the mixed forest after years .The results indicate that three years after the afforestation ,the preservation rate of the three species'young forest reaches 92% and the ear‐ly growth of the Choerospondias axillaris ,Alnus and Betula luminifera shows stronger fast -growing .The average height and DBH of Choerospondias axillaris is 6 .0m and 6 .5cm .That of Alnus 5 .8m and 6 .2cm and that of Betula luminifera is 4 .8m and 4 .4cm .Therefore ,Choerospondias axillaris is more suitable being the regenerated species on the Chinese fir cutover land in Tengchong ,which aims to create fast -growing and high yield industrial raw material forest .

  1. Population dynamics of Betula ermanii associated with soil change on treeline of northern slope of Changbai Mountains%长白山北坡林线岳桦种群与土壤关系

    Institute of Scientific and Technical Information of China (English)

    王晓东; 刘惠清

    2011-01-01

    以长白山北坡林线为研究区,选择4块样地(83个样方)进行岳桦种群径级结构与土壤理化性质关系的研究.采用单因子方差等方法分析土壤理化性质(有机质、全氮、全磷、砾石含量)和岳桦种群(灌丛和乔木)径级结构的关系,采用相关分析法做岳桦种群与土壤性质的动态变化分析.结果表明土壤因子对岳桦种群的扩张有一定的制约作用,但不足以决定林线的进退,岳桦通过不断调整生活型克服土壤约束以应对气候变化.%This paper, taking the treeline of northern slope of Changbai Mountains as the research object, selected 4 plots (83 quadrats) to study diameter-class structure of Betula ermanii population and soil physical and chemical properties. Four indices of soil properties (SOM, TN, AN and gravel contents) and diameter-class structure of two life forms (shrub and single-trunk) were analyzed by ANOVA, correlation analysis and other statistical analysis. The relationships between population dynamics and soil change were investigated by correlation analyses. The results showed soil physical and chemical properties on different quadrats had obvious difference with different expansion of Betula ermanii population. Soil factor had a certain restrictive effect on population dynamics. However,soil factor did not play a crucial role in treeline shifts and population expansion. The gradual weakening of soil properties has an effect on treeline shifts with the passage of time.The Betula ermanii population tended to continuously adjust its life forms to adapt air temperature change in order to overcome soil restrictions.

  2. 基质施肥对西南桦苗木生长的影响%Effects of Fertilizers on Seedling Growth of Betula alnoides

    Institute of Scientific and Technical Information of China (English)

    杨海娇; 王智斌; 庞岳燕; 李莲芳; 段安安; 王慷林

    2013-01-01

      The L16(45)orthogonal design was applied to implement 2 factors with each including 4 levels of organ⁃ic fertilizer and compound fertilizer. The purpose was to understand the influences of fertilizations on seedling growth of Betula alnoides. The results showed that:(1)There were significantly different effects of organic fertiliz⁃er,compound fertilizer and their interaction on seedling growth of basal diameter and heights for 150 and 210 days’old seedlings. the base diameter (BD)and heights of seedlings had a active response to. Organic fertilizer and their interaction were significantly presented a negative effects on the seedling growth,which indicated that Only compound fertilizer could promoted the seedling growth;(2)Among 16 treated combination,the sole fertiliza⁃tion of 50g/m2 compound fertilizer had basal diameter of 0.96mm (210d)and the heights of 6.7 and 9.8cm for 150 and 210 days’old seedlings,which were extremely larger than other treated combinations;(3)The optimal fer⁃tilizer combination was A1B2(organic fertilizer: 0kg/m2 with compound fertilizer 50g/m2),in terms of only com⁃pound fertilizer of 50g/m2 could promote seedling growth of B. alnoides. The optimal treated combination in theo⁃ry and practice was the consistent in the experiment.%  采用L16(45)正交试验设计进行有机肥和复合肥2因素各含4个水平的试验,了解其对西南桦苗木生长的影响。结果表明:(1)苗龄150d和210d时,有机肥、复合肥和二者的交互作用均极显著地影响西南桦苗木地径和苗高的生长。有机肥和二者的交互作用对苗木生长呈现极显著的负效应,单施复合肥即可达到促进西南桦苗木生长的目的;(2)有机肥和复合肥的16种配施中,单施复合肥50g/m2的平均地径和苗高在2个苗龄时均极显著地较其他配施的大,分别为0.96mm(210d)和6.7、9.8cm;(3)影响苗木生长的最佳配施为A1B2(有机肥0kg/m2

  3. Benefits in Mixed Forest of Cunninghamia lanceolata and Betula luminifera%杉木光皮桦混交林效益的研究

    Institute of Scientific and Technical Information of China (English)

    黄承标; 邓绍林; 农必昌

    2001-01-01

    对桂西北杉木光皮桦混交林和杉木纯林的对比研究表明,35年生杉桦混交林的立木蓄积量为441.087 m3*hm-2,比杉木纯林高3.6%。混交林枯枝落叶层现存量及其N,P,K,Ca,Mg等元素的质量浓度分别为13.18 t*hm-2,158.3,6.1,16.5,86.3和32.3 kg*hm-2,分别比杉木纯林高9.7%,76.7%,69.4%,96.4%,83.2%,17.0%。混交林地(0~100 cm)土壤容重为0.81~1.22 g*hm-3,比杉木纯林低1.0%~8.0%,而土壤孔隙度,通气度和持水量分别比杉木纯林高2.0%~3.9%。土壤有机质、全氮、水解氮、有效磷和速效钾分别比杉木纯林高5.5%~49.8%。%Comparative studies were conducted on mixed forest of Cunninghamia lanceolata and Betula luminifera and pure Cunninghamia lanceolata forest in westren of Guangxi.The result showed that the growing stocks in stands of 35-year-old mixed forest was 441.087 m3*hm-2,which was by 3.6% higher than those of the same years old forests of pure Cunninghamia lanceolata.The mean standing crop of litteron forest floor in mixed forest was 13.18 t*hm-2 and the mass concentration of N,P,K,Ca,Mg were 158.3,6.1,16.5,86.3,32.3 kg*hm-2,respectively.Being by 9.7%,76.7%,69.4%,96.4%,83.2%,17.0% higher than that of pure Cunninghamia lanceolata forest,respectively.In mixed forest,the soil volume weight (0~100 cm) were 0.81~1.22 g*cm-3,were 1.0%~8.0% lower than that of pure Cunninghamia lanceolata,but it total poresity aeration porosity and moisture capacty were 2.0%~3.9% higher than that of pure Cunninghamia lanceolata,respectively.The nutrientconcentration of organic matter,TN,hydrolazable N,available P and repidly available K in the soil,being by 5.5%~49.8% higher than that of pure Cunninghamia lanceolata,respectively.

  4. A noninvasive optical system for the measurement of xylem and phloem sap flow in woody plants of small stem size.

    Science.gov (United States)

    Helfter, Carole; Shephard, Jonathon D; Martinez-Vilalta, Jordi; Mencuccini, Maurizio; Hand, Duncan P

    2007-02-01

    Over the past 70 years, heat has been widely used as a tracer for estimating the flow of water in woody and herbaceous plants. However, most commercially available techniques for monitoring whole plant water use are invasive and the measurements are potentially flawed because of wounding of the xylem tissue. The study of photosynthate transport in the phloem remains in its infancy, and little information about phloem transport rates is available owing to the fragility of the vascular tissue. The aim of our study was to develop a compact, stand-alone non-invasive system allowing for direct detection of phloem and xylem sap movement. The proposed method uses a heat pulse as a tracer for sap flow. Heat is applied to the surface of the stem with a near-infrared laser source, and heat propagation is monitored externally by means of an infrared camera. Heat pulse velocities are determined from the thermometric data and related to the more useful quantity, mass flow rate. Simulation experiments on the xylem tissue of severed silver birch (Betula pendula Roth.) branch segments were performed to assess the feasibility of the proposed approach, highlight the characteristics of the technique and outline calibration strategies. Good agreement between imposed and measured flow rates was achieved leading to experimentation with live silver birch and oak (Quercus robur L.) saplings. It was demonstrated that water flow through xylem vessels can be monitored non-invasively on an intact stem with satisfactory accuracy despite simultaneous sugar transport in the phloem. In addition, it was demonstrated that the technique allows for unequivocal detection of phloem flow velocities.

  5. Effects of extreme spring temperatures on phenology: a case study from Munich and Ingolstadt

    Science.gov (United States)

    Jochner, Susanne; Menzel, Annette

    2010-05-01

    Extreme events - e.g. warm spells or heavy precipitation events - are likely to increase in the future both in frequency and intensity. Therefore, research on extreme events gains new importance; also in terms of plant development which is mostly triggered by temperatures. An arising question is how plants respond to an extreme warm spell when following an extreme cold winter season. This situation could be studied in spring 2009 in the greater area of Munich and Ingolstadt by phenological observations of flowering and leaf unfolding of birch (Betula pendula L.) and flowering of horse chestnut (Aesculus hippocastanum L.). The long chilling period of winter 2008 and spring 2009 was followed by an immediate strong forcing of flowering and leaf unfolding, especially for birch. This extreme weather situation diminished the difference between urban and rural dates of onset. Another important fact that could be observed in the proceeding period of December 2008 to April 2009 was the reduced temperature difference among urban and rural sites (urban heat island effect). Long-term observations (1951-2008) of the phenological network of the German Meteorological Service (DWD) were used to identify years with reduced urban-rural differences between onset times in the greater area of Munich in the past. Statistical analyses were conducted in order to answer the question whether the sequence of extreme warm and cold events leads to a decreased difference in phenological onset times or if this behaviour can be attributed to extreme warm springs themselves or to the decreased urban heat island effect which is mostly affected by general atmospheric circulation patterns.

  6. Vaccination for birch pollen allergy. Induction of affinity-matured or blocking IgG antibodies does not account for the reduced binding of IgE to Bet v 1

    DEFF Research Database (Denmark)

    Svenson, Morten; Jacobi, Henrik H; Bødtger, Uffe;

    2003-01-01

    Specific allergy vaccination (SAV) is associated with increased levels of allergen specific IgG in serum. It is not clear, however, to what extent qualitative changes in allergen binding to IgG may be induced as well. We therefore analyzed the binding of the major allergen in pollen of birch.......001). These results show that high avidity IgG of low inter-individual difference in Bet v 1 binding quality is the dominant binding factor of Bet v 1 in sera of birch pollen-allergic patients, and that SAV-induced inhibition of binding of Bet v 1 to IgE can be explained mainly or solely by increased amounts of IgG....

  7. STUDY ON THOUSAND-SEED WEIGHT,LONGEVITY AND VITALITY OF SEEDS OF BETULA LUMINIFERA%光皮桦种子千粒重、寿命及生命力研究

    Institute of Scientific and Technical Information of China (English)

    祝小科; 朱守谦

    2003-01-01

    The thousand-seed weight, germination rate and vitality of seeds for Betula luminifera were studied. The results showed that the thousand-seed weight was different in various habitats, and varied with the age and the part of crown and fruit. The seed had a longevity of 32—37 days in general and with a characteristic of the rapid germination. The seed had a high germination rate during the early stage or perk stage of seed dispersal, and a lower germination rate during the end stage. The germination rate and vitality of mature seed reduced with the increase of the storing time, the change in seed ger-mination was significantly different at the various ages and habitats.

  8. 长白山北坡岳桦林线变动的水热条件分析%Water and Heat Changes of Betula ermanii Treeline on Northern Slope of Changbai Mountains

    Institute of Scientific and Technical Information of China (English)

    王晓东; 刘惠清

    2011-01-01

    近50年来长白山北坡林线种群呈现明显的扩张态势.为揭示林线变动机制,本文以长白山天池气象站的气象数据(1953-2007年)为基础,结合野外的气温观测,以温暖指数(WI)及湿润指数(WI)为生态气候指标,以16℃·月和68.8mm/℃·月为阈值,通过数据保证率的计算推测55年来长白山北坡岳桦林线的水热条件变化.结果表明:以WI和HI指标确定的林线位置分别在1975~2460 m和1584~2231m.WI与HI变化对林线高度变动影响的交互作用不显著(P>0.05),WI与HI变化呈显著负相关(P<0.01),两种林线变化也呈负相关(r=0.11<0),交互作用和相关分析结果显示水热条件的不同步变化使岳桦林线上侵不能达到各自的潜在高度,林线位置波动在1975~2231m.林线上缘波动的复杂程度高于下缘,波动幅度与胁迫力的大小呈正相关.%The treeline of Betula ermanii population had an obviously expanding trend on the northern slope of the Changbai Mountains in recent 50 years. In order to examine the changing mechanism of treeline, in this study, based on the data from Tianchi meteorological station (2624 m altitude) regarded as a referencing site (1953-2007) and the air temperature field measurement, using two eco-climatic preferences which were warmth index (WI) and humid index (HI), the ecotone boundary between Betula ermanii and tundra on the northern slope of the Changbai Mountains was determined by assurance ratio. The results were calculated by using the thresholds at 16 ℃· month and 68.8 mm/℃·month, and they showed that the two treelines were at 1975-2460 m and 1584-2231 m respectively. The interaction influence of WI and HI changes on treeline was not significant (p>0.05). There was a significant negative correlation between WI and HI change (p<0.01). In addition, there was a negative correlation between two treelines changes (r =-0.11<0). The results of correlation and interaction analysis indicated that the

  9. 天然白桦种苗光合作用日进程%Daily Course of Photosynthesis in Seedlings of Natural Birch

    Institute of Scientific and Technical Information of China (English)

    王爱民; 刘志学; 祖元刚

    2001-01-01

    In this research, the most advanced system for photosynthesis-LI 6400 was used in seedlings of natural birch which is one kind of multi-function species. The diurnal course of photosynthetic rate of birch shows a single peak (10.53 μ molCO2 m-2s-1) which reaches at 14 o'clock. There exist no “midday depression” in the photosynthesis. At 14 o'clock, while the value of stoma limitation (0.3172) and water pressure deficits of leaf (2.46 kPa) reach their peaks, the water utilization efficiency is still high and the highest value (2.97 μ1 molCO2 m-2 s-1 mm H2O m-2s-1) appears at 12 o'clock. And the most value of apparent quantum yield occurs at 8 o'clock. But the climax value of transpiration rate appears at 14 o'clock (4.82 mmH2O m-2s-1). In the diurnal variation of photosynthetic rate, high value keeps on during at least 4 hours. This increase the amount of photosynthesis in daily course, furthermore, it makes advantage to the growth of birch.%本研究采用最先进的光合作用测定系统LI-6400测定多功能树种白桦种苗的光合作用.天然白桦种苗光合速率日进程表现为 单峰曲线,在下午14:00时达到最高峰(10.53 μ mol CO2 m-2 s-1),.其光合作用不存在“午休现象”.在14:00时,白桦的气孔限制值 (0.3172)和水分饱和亏缺(2.46 kPa)分别达到最大值,此时其水分利用效率较高,在中午12:00时水分利用率达到最大值(2.97μ molCO2m-2 s-1mmH2Om-2s-1).在早上8:00,白桦获得一天中最大的表观量子效率;其蒸腾速率在下午14:00时最大(4.82mmH2O m-2s-1).在光合速率的日进程中,白桦高光合速率值持续至少4个小时.这使得白桦的光合作用量得以有效累积,进而为其生长创 造了有利条件.

  10. 白桦APETALA2( AP2)转录因子基因的分离及其表达%Isolation and Expression of APETALA2 Transcription Factor Gene in Betula platyphylla

    Institute of Scientific and Technical Information of China (English)

    张妍; 刘瀛; 孙丰宾; 戴超; 刘雪梅

    2012-01-01

    AP2 gene is a key transcription factor involved in flower development in plants. The full cDNA of AP2 gene was isolated from Betula platyphylla Suk. by methods of reverse transcription polymerase chain reaction ( RT-PCR) and 5' and 3' rapid amplification of cDNA ends (RACE) . Results showed that AP2 gene contains an open reading frame (ORF) ,of 1554bp encoding 517 amino acids. Molecular weight of the deduced protein of BpAPl is 56.74kDa and the theoretical isoelectric point is 6. 34. The AP2 functional sites and characterized domains were confirmed in the sequence, so the isolated gene was named as BpAPl, and registered in Gen Bank with accession number JN247408. The deduced amino acid sequence shared 51%~77% of identity with other twelve plant species, the maximum identity with Arabidopsis thaliana (77% ) and minimum identity with Pinus thunbergii (51% ). A phylogenetic tree was constructed according to multiple sequences alignment of all the thirteen plant species. Transcription expression of BpAPl was analyzed by qRT-PCR in different tissues and periods in B. platyphylla. Results showed that BpAPl was more highly expressed in floral organs than in vegetative organs, expression quantity more highly in young tissues than in mature tissues. It inferred that BpAP2 transfactor involved in the regulation of development of floral organs and meristematic tissues in Betula. In addition, a natural male inflorescence- abnormal mutant of B. platyphylla was used for transcription analysis of BpAP2. Results showed that BpAPl gene is expressed up-regulatedly in female inflorescences, while down-regulation in male inflorescences, young leaves and young shoots, which predicted that BpAPl should be involved in regulation and expression of multiple genes, and not only be involved in the development of floral organs, but also play some roles in the development of vegetative tissues.

  11. GC-MS Analysis of Aroma Components of Birch Sap Wine with Different Aging Time%不同陈酿时期的桦树液发酵酒香气成分的GC-MS分析

    Institute of Scientific and Technical Information of China (English)

    曲迪; 连奎

    2016-01-01

    The aroma components in birch sap wine were fermented with different aging time were extracted by solvent extract and analyzed by GC-MS. The results indicated that the identified amount of aroma components of two birch sap wine is as follow:one year aged 56, two years aged 44, and their common aroma components are 22. Among them, the main aroma components are 7. The mainly aromatic substance benzene ethanol, with their unique aroma components, constitutes the unique aroma style of birch sap wine. Sensory olfactory evaluation found that two years aged of birch sap wine aroma is richer and soft.%采用溶剂萃取法提取桦树液发酵酒的香气成分,利用气相色谱-质谱(GC-MS)联用技术对不同时期的桦树液发酵酒的香气成分进行分析研究。结果表明,陈酿1年的桦树液发酵酒中有56种香气成分;陈酿2年的桦树液发酵酒中有44种香气成分,其中,共同的香气成分22种,有7种是主体香气成分。主要呈香物质是苯乙醇,加上各自独有的香气成分共同构成了桦树液发酵酒的特有香气风格。经感官嗅闻评定,陈酿2年的桦树液发酵酒的香气更为浓郁优雅、协调悦人。

  12. Effects of tree species richness and composition on moose winter browsing damage and foraging selectivity: an experimental study.

    Science.gov (United States)

    Milligan, Harriet T; Koricheva, Julia

    2013-07-01

    The optimal foraging theory, the nutrient balance hypothesis, and the plant association theories predict that foraging decisions and resulting tree damage by large mammalian browsers may be influenced by the species richness and species composition of forest stands. This may lead to either associational susceptibility (increased damage on a focal plant in a mixed stand) or associational resistance (reduced damage in a mixed stand). Better understanding of the mechanisms and the relative importance of tree species richness and composition effects on foraging by mammalian browsers is needed to support sustainable management of forests and mammal populations. However, existing knowledge of forest diversity effects on foraging by large mammalian browsers comes largely from observational studies while experimental evidence is limited. We analysed winter browsing by moose (Alces alces L.) in a long-term, large-scale experiment in Finland, which represents a tree species richness gradient from monocultures to 2-, 3- and 5-species mixtures composed of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L.), Siberian larch (Larix sibirica Ledeb.), silver birch (Betula pendula Roth.) and black alder (Alnus glutinosa L.). The intensity of browsing per plot increased with tree species richness while browsing selectivity decreased with tree species being targeted more equally in species-rich mixtures. Tree species composition of a plot was also an important determinant of intensity of browsing. The greatest browsing occurred in plots containing preferred species (pine and birch) while intermediate preference species (larch and alder) experienced associational susceptibility when growing with pine and birch compared with their monocultures or mixtures without pine and birch. In contrast, we found no evidence of associational resistance; the presence of a least preferred species (spruce) in a mixture had no significant effect on moose browsing on other tree species. We

  13. Phenogenetic response of silver birch populations and half-sib families to elevated ozone and ultraviolet-B radiation at juvenile age.

    Science.gov (United States)

    Pliura, Alfas; Baliuckiene, Asta; Baliuckas, Virgilijus

    2008-11-01

    Phenogenetic response of silver birch populations and half-sib families to separate and combined elevated ozone (O(3)) concentrations and ultraviolet-B (UV-B) radiation dozes was studied at juvenile age in the climatic chambers. Significant population and family effects were found for seedling height, lamina width, and leaf damage. The exposure to UV-B radiation decreased genetic variation at the stage of seed germination. Complex exposure to UV-B and O(3) caused an increase of genetic variation at the stage of intensive seedling growth: seedling height genetic variation in separate treatments increased from 23.7-38.6 to 33.7-65.7%, the increase for lamina width was from 10.2-13.9 to 13.6-31.8%. Different populations and families demonstrated differing response to elevated complex UV-B and O(3) exposure. Changes of genetic intra-population variation were population-specific. Such changes in genetic variation under the impact of stressors can alter adaptation, stability, and competitive ability of regenerating populations in a hardly predictive way.

  14. Investigation of antiproliferative effect of ether and ethanol extracts of birch polypore medicinal mushroom, Piptoporus betulinus (Bull.:Fr.) P. Karst. (higher Basidiomycetes) in vitro grown mycelium.

    Science.gov (United States)

    Cyranka, Małgorzata; Graz, Marcin; Kaczor, Jozef; Kandefer-Szerszeń, Martyna; Walczak, Katarzyna; Kapka-Skrzypczak, Lucyna; Rzeski, Wojciech

    2011-01-01

    This paper describes the study conducted to evaluate the antiproliferative activity of ether and ethanol extracts isolated from Piptoporus betulinus against cancer-derived cells. The fungal material used for extract preparation and further experiments was obtained from in vitro grown strains of P. betulinus. To the best of the authors’ knowledge, this is the first study evaluating antiproliferative potential of in vitro cultured birch polypore fungus. The effect of ether and ethanol extracts on cell proliferation, viability, and adhesion was assessed on colorectal adenocarcinoma cancer cell line LS180, whereas the cytotoxicity effect was investigated in normal colon epithelium-derived cell line CCD 841 CoTr. Studied extracts highly decreased the viability of cancer cells, slightly inhibiting proliferation and tumor cell adhesion in a time- and dose-dependent manner. Cytotoxicity of extracts against cells of normal colon epithelium origin was observed only at the highest studied concentration. The obtained results may seem interesting in comparison with previous studies on water extracts from natural grown P. betulinus. Future research on mycelial extract activity, as well as the content analysis, is needed.

  15. Crystallographically mapped ligand binding differs in high and low IgE binding isoforms of birch pollen allergen bet v 1.

    Science.gov (United States)

    Kofler, Stefan; Asam, Claudia; Eckhard, Ulrich; Wallner, Michael; Ferreira, Fátima; Brandstetter, Hans

    2012-09-07

    The ability of pathogenesis-related proteins of family 10 to bind a broad spectrum of ligands is considered to play a key role for their physiological and pathological functions. In particular, Bet v 1, an archetypical allergen from birch pollen, is described as a highly promiscuous ligand acceptor. However, the detailed recognition mechanisms, including specificity factors discriminating binding properties of naturally occurring Bet v 1 variants, are poorly understood. Here, we report crystal structures of Bet v 1 variants in complex with an array of ligands at a resolution of up to 1.2 Å. Residue 30 within the hydrophobic pocket not only discriminates in high and low IgE binding Bet v 1 isoforms but also induces a drastic change in the binding mode of the model ligand deoxycholate. Ternary crystal structure complexes of Bet v 1 with several ligands together with the fluorogenic reporter 1-anilino-8-naphthalene sulfonate explain anomalous fluorescence binding curves obtained from 1-anilino-8-naphthalene sulfonate displacement assays. The structures reveal key interaction residues such as Tyr83 and rationalize both the binding specificity and promiscuity of the so-called hydrophobic pocket in Bet v 1. The intermolecular interactions of Bet v 1 reveal an unexpected complexity that will be indispensable to fully understand its roles within the physiological and allergenic context.

  16. The seasonal symptoms of hyposensitized and untreated hay fever patients in relation to birch pollen counts: correlations with nasal sensitivity, prick tests and RAST.

    Science.gov (United States)

    Viander, M; Koivikko, A

    1978-07-01

    A 2 year prospective study of thirty-eight birch pollen-sensitive hay fever patients under specific immunotherapy and of nineteen untreated control patients showed a significant correlation between the total seasonal symptom scores of the patients and their clinical sensitivities assessed by the RAST and a graded nasal test. The agreement between a positive nasal test and a positive RAST was 74%. In the early season with low pollen counts the onset of symptoms was significantly associated with high sensitivity of the patients, while many patients showed symptoms in the late season irrespective of their nasal and RAST sensitivity. About 90% of both the treated and the untreated patients reported mild symptoms when the pollen count exceeded 80/m(3) in the early season. 80% of them still had symptoms when the count was below 30/m(3) in the late pollen season. Although hyposensitization therapy had no effect on the occurrence of the mild symptoms, the treated patinets had severe symptoms significantly less often than the untreated ones on days with high pollen counts.

  17. Effect of CuSO4 Content in the Plating Bath on the Properties of Composites from Electroless Plating of Ni-Cu-P on Birch Veneer

    Directory of Open Access Journals (Sweden)

    Bin Hui

    2014-04-01

    Full Text Available A wood-based composite was prepared via simple electroless Ni-Cu-P plating on birch veneer for EMI shielding. The effects of CuSO4•5H2O concentration on the metal deposition, elemental composition, phase structure, surface morphology, wettability, surface resistivity, and shielding effectiveness of coatings were investigated. The coatings were characterized using X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, and scanning electron microscopy (SEM. When the CuSO4•5H2O concentration was increased from 0.6 g/L to 2.2 g/L, the metal deposition was decreased from 79.61 g/m2 to 66.44 g/m2. Elemental composition showed that the copper content in the coating increased significantly, whereas the nickel content was reduced significantly and the phosphorus content was slightly reduced. The crystallinity of coatings increased, and fine-grain structure was observed, with higher copper content. Ni-Cu-P deposition improved the hydrophobic properties when the maximum static contact angle increased from 77.5° to 116.5°. The lowest surface resistivity was 367.5 mΩ/cm2, and the EMI shielding effectiveness of Ni-Cu-P-coated veneers was higher than 60 dB in frequencies ranging from 9 kHz to 1.5 GHz.

  18. Dicty_cDB: FC-IC1683 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available equence. 44 0.16 2 CD269836 |CD269836.1 T143A02135F (FHIG:A) Ectomycorrhiza plate...70770.1 T143A01691F (FHIG:A) Ectomycorrhiza plate culture Betula pendula/Paxillus involutus mixed EST librar

  19. Characteristics of nutrient contents and storages i n Castanopsis hystrix and Betula alnoides%红椎和西南桦营养元素的含量与储量特征

    Institute of Scientific and Technical Information of China (English)

    谭玲; 何友均; 覃林; 陈绍志

    2015-01-01

    Nutrient elements in different organs of the plant and different contents or storages of nutrient elements in the same organs,not only reflect the plant’s own biological characteristics,but also reflect the plant under certain habitats capacity to absorb and accumulation of mineral from soil.To illustrate the characteristics of nutrient element contents and storages of different valuable local forestation hardwood species in the southern subtropical area of Chi-na,we studied the contents and storages of five nutrient elements (N,P,K,Ca and Mg)in Castanopsis hystrix and Betula alnoides from the Experimental Centre of Tropical Forestry of Chinese Academy of Forestry located in Pingx-iang,Guangxi.We have got some meaningful results from collecting plant samples,laboratory test and statistical a-nalysis method.The total contents of these five nutrient elements in different organs of Castanopsis hystrix and Bet-ula alnoides were in the order of leaf>fine root>twig>medium root>thick root>bark>root tip>stem.The con-tents of N and K were the highest among the five elements,followed by Ca and Mg,while P was the lowest in various organs of the two trees.The contents of N and P in leaf were significantly higher than those in other organs for Cas-tanopsis hystrix and Betula alnoides (Ptwig>bark>leaf>thick root>fine root>medium root.The nutrient utilization effi-ciency of Castanopsis hystrix was slightly higher than that of Betula alnoides.The study revealed that the nutritional requirements of Castanopsis hystrix and Betula alnoides would provide theoretical basis for adj usting and improving the two trees growing environment,as well as making forest land nutrient management strategies.%营养元素在植物不同器官及不同营养元素在同一器官中的含量与储量特征,不仅反映植物自身的生物学特性,而且还反映了植物在一定的生境下从土壤中吸收和蓄积矿质养分的能力.为了阐明我国南亚热带不同珍优乡土阔叶造

  20. The Selection of Reference Genes for Quantitative PCR in Betula luminifera%光皮桦实时荧光定量PCR内参基因的筛选

    Institute of Scientific and Technical Information of China (English)

    刘文哲; 牛明月; 李秀云; 林二培; 黄华宏; 童再康

    2016-01-01

    [Objective]Real-time quantitative PCR ( RT-qPCR) has become the preferred approach to the quantification of gene expression. Besides its simplicity and efficiency,this method requires suitable reference genes to guarantee the accuracy of the quantification. Betula luminifera is not only a high-quality timber species with excellent wood properties, but also an ideal species for genetic study. Stability of candidate reference genes in different tissues was investigated using RT-qPCR and expression analysis software to select suitable reference genes,the reliability of the reference genes was further verified through expression analysis of two functional genes in different tissues. [Method]16 housekeeping genes were chosen as candidate reference genes,and specificity of the primers was investigated by agarose gel electrophoresis and melting curve of target amplified fragments. The software of geNorm,NormFinder and BestKeeper were used to analyze expression stability of reference genes in 16 different tissues. Furthermore,two functional genes were selected to verify the reliability of the suitable reference genes. [Result]Electrophoresis results showed distinct PCR products with the expected size,and the single-peak melting curves further indicated the specificity of the selected primers. Except 18S,the Ct values of the candidate genes were all between 25 to 30 ,indicating the expressions of these candidate genes were quite stable in different tissues. EF1α was characterized as the most stable gene based on NormFinder and BestKeeper analysis, while TATA was ranked in the first place according to geNorm. UBi-lp showed the most unstable expression. Furthermore, three top-stable genes ( EF1α,TATA and UBi4 ) and the unstable gene UBi-lp were chosen to verify the reliability of the reference genes. As results,the two target genes showed consistent expression profiles when normalized by the three top-ranked reference genes,and UBi-lp failed to standardize the expression

  1. The Presence of Pretreated Lignocellulosic Solids from Birch during Saccharomyces cerevisiae Fermentations Leads to Increased Tolerance to Inhibitors--A Proteomic Study of the Effects.

    Directory of Open Access Journals (Sweden)

    Rakesh Koppram

    Full Text Available The fermentation performance of Saccharomyces cerevisiae in the cellulose to ethanol conversion process is largely influenced by the components of pretreated biomass. The insoluble solids in pretreated biomass predominantly constitute cellulose, lignin, and -to a lesser extent- hemicellulose. It is important to understand the effects of water-insoluble solids (WIS on yeast cell physiology and metabolism for the overall process optimization. In the presence of synthetic lignocellulosic inhibitors, we observed a reduced lag phase and enhanced volumetric ethanol productivity by S. cerevisiae CEN.PK 113-7D when the minimal medium was supplemented with WIS of pretreated birch or spruce and glucose as the carbon source. To investigate the underlying molecular reasons for the effects of WIS, we studied the response of WIS at the proteome level in yeast cells in the presence of acetic acid as an inhibitor. Comparisons were made with cells grown in the presence of acetic acid but without WIS in the medium. Altogether, 729 proteins were detected and quantified, of which 246 proteins were significantly up-regulated and 274 proteins were significantly down-regulated with a fold change≥1.2 in the presence of WIS compared to absence of WIS. The cells in the presence of WIS up-regulated several proteins related to cell wall, glycolysis, electron transport chain, oxidative stress response, oxygen and radical detoxification and unfolded protein response; and down-regulated most proteins related to biosynthetic pathways including amino acid, purine, isoprenoid biosynthesis, aminoacyl-tRNA synthetases and pentose phosphate pathway. Overall, the identified differentially regulated proteins may indicate that the likelihood of increased ATP generation in the presence of WIS was used to defend against acetic acid stress at the expense of reduced biomass formation. Although, comparative proteomics of cells with and without WIS in the acetic acid containing medium

  2. Numerical responses of saproxylic beetles to rapid increases in dead wood availability following geometrid moth outbreaks in sub-arctic mountain birch forest.

    Directory of Open Access Journals (Sweden)

    Ole Petter Laksforsmo Vindstad

    Full Text Available Saproxylic insects play an important part in decomposing dead wood in healthy forest ecosystems, but little is known about their role in the aftermath of large-scale forest mortality caused by pest insect outbreaks. We used window traps to study short-term changes in the abundance and community structure of saproxylic beetles following extensive mortality of mountain birch in sub-arctic northern Norway caused by an outbreak of geometrid moths. Three to five years after the outbreak, the proportion of obligate saproxylic individuals in the beetle community was roughly 10% higher in forest damaged by the outbreak than in undamaged forest. This was mainly due to two early-successional saproxylic beetle species. Facultative saproxylic beetles showed no consistent differences between damaged and undamaged forest. These findings would suggest a weak numerical response of the saproxylic beetle community to the dead wood left by the outbreak. We suggest that species-specific preferences for certain wood decay stages may limit the number of saproxylic species that respond numerically to an outbreak at a particular time, and that increases in responding species may be constrained by limitations to the amount of dead wood that can be exploited within a given timeframe (i.e. satiation effects. Low diversity of beetle species or slow development of larvae in our cold sub-arctic study region may also limit numerical responses. Our study suggests that saproxylic beetles, owing to weak numerical responses, may so far have played a minor role in decomposing the vast quantities of dead wood left by the moth outbreak.

  3. Phenological diversity in the interactions between winter moth (Operophtera brumata) larvae and parasitoid wasps in sub-arctic mountain birch forest.

    Science.gov (United States)

    Vindstad, O P L; Hagen, S B; Jepsen, J U; Kapari, L; Schott, T; Ims, R A

    2011-12-01

    Population cycles of the winter moth (Operophtera brumata) in sub-arctic coastal birch forests show high spatiotemporal variation in amplitude. Peak larval densities range from levels causing little foliage damage to outbreaks causing spatially extensive defoliation. Moreover, outbreaks typically occur at or near the altitudinal treeline. It has been hypothesized that spatiotemporal variation in O. brumata cycle amplitude results from climate-induced variation in the degree of phenological matching between trophic levels, possibly between moth larvae and parasitoids. The likelihood of mismatching phenologies between larvae and parasitoids is expected to depend on how specialized parasitoids are, both as individual species and as a guild, to attacking specific larval developmental stages (i.e. instars). To investigate the larval instar-specificity of parasitoids, we studied the timing of parasitoid attacks relative to larval phenology. We employed an observational study design, with sequential sampling over the larval period, along an altitudinal gradient harbouring a pronounced treeline outbreak of O. brumata. Within the larval parasitoid guild, containing seven species groups, the timing of attack by different groups followed a successional sequence throughout the moth's larval period and each group attacked 1-2 instars. Such phenological diversity within parasitoid guilds may lower the likelihood of climate-induced trophic mismatches between victim populations and many/all of their enemies. Parasitism rates declined with increasing altitude for most parasitoid groups and for the parasitoid guild as a whole. However, the observed spatiotemporal parasitism patterns provided no clear evidence for or against altitudinal mismatch between larval and parasitoid phenology.

  4. Population Structure Dynamics of Betula luminifera Secondary Forest in Jixi County of Anhu i Province, China%绩溪光皮桦次生林的种群动态1)

    Institute of Scientific and Technical Information of China (English)

    万志兵; 程国源; 丁强强; 方乐金

    2014-01-01

    对绩溪光皮桦次生林种群进行了调查,以种群生命表及生存分析理论为基础,以林木径级结构代表龄级结构,编制了绩溪光皮桦种群静态生命表,分析绩溪光皮桦次生林种群结构的动态变化特点。结果表明:光皮桦种群结构呈纺锤型,幼龄个体数量偏少,中龄个体数居多,而老龄个体则相对数量较少,说明种群有衰退的趋势;在第Ⅴ龄级时该种群出现死亡高峰,其种群存活曲线属 Deevey-Ⅱ型;绩溪光皮桦次生林种群具有前期种群数量少,中期稳定,末期衰退的特点。%The experiment was conducted to determine population structure dynamic and quantitative statistics of Betula luminif-era in a secondary forest of Jixi county, Anhui Province.By the population life table and survival analysis, the life table of Betula luminifera population was constructed and age classes were replaced with size-classes, therefore, the population structure dynamic of B.luminifera was explored.The results of the population structure illustrates a spindle type with a gradually decline in population.The individual plants of class I and class II are not enough.The survival curve in the pop-ulation is a Deevey-Ⅱtype with a peak of mortality in size class V.The population size ofB .luminifera declines sharply in early stage, stabilizes in middle stage and falls rapidly in last stage.

  5. 护岸金丝柳根系分布特征和力学特性分析%Distribution and tensile mechanical properties of Salix × aureo-pendula root ;system in soil bioengineering revetment

    Institute of Scientific and Technical Information of China (English)

    郭凯力; 高甲荣; 马岚; 刘国华; 王兵; 易扬; 王舒; 张腾飞

    2015-01-01

    In order to understand the effect of different soil bioengineering measures on the distribution and tensile mechanical properties of root system, we investigated root biomass distribution and conducted tensile tests on Salix × aureo-pendula roots from four types of soil bioengineering revetment, i. e. , rooted cutting, live staking, fascines and brush mattress in the experimental base located at Liuli River in Huairou District, Beijing. All the revetments have been finished for five years. All tested roots were divided into different diameter classes and soil layers for biomass measure and tensile mechanical analysis. The results showed that:root system concentrated in 0--40 cm soil layer and root system had the highest density in 0--20 cm soil layer in revetments with brush mattress and fascines. There was the highest biomass of roots with diameter less than 1 mm in brush mattress measure, accounting for 31. 3%of total biomass, followed by that with fascines measure (19. 2%) . The root tensile force increased with the increasing root diameter in a power function pattern among all bioengineering measures. In 0--20 cm layer, the average tensile force had a significant difference, ranking from high to low as rooted cutting>live staking>fascines>brush mattress, while the average ultimate elongation among different measures followed the order of brush mattress> fascines >live staking > rooted cutting. According to our results, the four soil bioengineering measures can be divided into two types: brush mattress and fascines are suitable to be applied to the area near water surface to alleviate loss of topsoil; rooted cutting and live staking can be established on bank slope to increase the slope stabilization of deeper soil layer.%了解不同土壤生物工程措施下根系分布特征与抗拉特性对土壤生物工程措施的合理配置意义重大。以竣工5年的北京市怀柔区土壤生物工程试验区4种不同种植方式(埋根

  6. Study on Anatomy and Physiology of Graft Healing Process in‘P .armeniaeae f olia/P .betulae f olia’%‘杏叶梨/杜梨’嫁接愈合过程的解剖学与生理学研究

    Institute of Scientific and Technical Information of China (English)

    黄曼娜; 孙华丽; 宋健坤; 杨英杰; 王然

    2014-01-01

    针对‘杏叶梨(Pyrus armeniacaefolia/杜梨(Pyrus betulifolia)’嫁接组合出现的“小脚”现象,以杜梨自体嫁接(杜梨/杜梨)为对照,进行了愈合过程解剖结构观察及生理变化分析,以探讨梨嫁接亲和性机理。结果表明:杏叶梨的材皮比显著小于杜梨;砧穗嫁接愈合过程解剖学观测可大致分为4个阶段,分别为隔离层形成、愈伤组织形成、砧穗愈伤组织相互接触及分化和新输导组织形成;‘杏叶梨/杜梨’嫁接口愈合速度滞后‘杜梨/杜梨’6d;与‘杜梨/杜梨’自体嫁接对照相比,‘杏叶梨/杜梨’嫁接口处多酚氧化酶(PPO )与苯丙氨酸解氨酶(PA L )活性变化幅度较大,除个别观测点(嫁接后18d)外,PPO活性大部分时期高于‘杜梨/杜梨’;木质素含量在两种嫁接组合的愈合后期均表现增加趋势,但‘杜梨/杜梨’增加趋势更明显;‘杜梨/杜梨’可溶性糖含量高峰早于‘杏叶梨/杜梨’;两种嫁接组合可溶性蛋白含量变化趋势相近,但‘杜梨/杜梨’嫁接口可溶性蛋白含量显著高于‘杏叶梨/杜梨’。%On the scion overgrowing phenomenon of ‘P . armeniaeae f olia/P .betulae f olia’ in field ,the P .betuli f olia antilogous grafting was taken as contrast and the mechanism of graft compatibility was dis-cussed by observing the effects of cicatrization on the anatomical structures and analyzing the physiological change of graft union .The results revealed that the ratio of wood and bark of P .armeniaeaefolia was sig-nificant less than P .betulae f olia .Observing the anatomical structures of graft union ,we found that the graft healing process was approximately divided into 4 stages ,which were the insulating layer forming , callus forming ,connecting and differentiating of callus of the scion and stock ,and the conducting tissue forming respectively .On the rate of cicatrization of graft union ,

  7. Xylem Characteristics of Tension Wood and Endogenous Hormones Distributions during Its Early Formation Period in Betula luminifera%光皮桦应拉木的显微特征及其形成早期内源激素分布

    Institute of Scientific and Technical Information of China (English)

    何辉; 楼雄珍; 林二培; 俞友明; 童再康; 黄华宏

    2016-01-01

    【目的】分析光皮桦应拉木的显微结构、理化特性及其形成早期的内源激素分布,以期为揭示应拉木形成机制提供理论依据。【方法】以无性系1V25-2为材料,通过人工拉弯诱导形成应拉木,测定其主要显微特征和物理化学特性,并应用 ELISA分析其形成早期阶段主要内源激素的分布规律。【结果】经12个月的拉弯处理,应拉区木质部的细胞壁明显增厚,纤维平均双壁厚是对应木的1.8倍,形成明显的胶质纤维层。应拉木的平均纤维长度、纤维素含量均明显大于对应木,而木质素含量则相反。拉弯处理的早期阶段,不同木质部类型中的4种激素含量呈现不同的分布特征。应拉区木质部中 IAA含量均小于对应区,但仅处理7天的木质部样品两区块间差异达到显著水平。GAs(GA1+GA3)也表现出与 IAA类似的变化规律。除拉弯处理6 h的样品外,应拉区木质部 BR 含量均显著小于对应区和对照,且随着处理时间延长对应区木质部 BR含量呈递增趋势。ZR含量在应拉区和对应区木质部间皆无明显差异,但表现出随处理时间延长而增加的趋势,处理7天时2区块的 ZR 含量均显著高于对照。【结论】经12个月的拉弯处理,光皮桦应拉区木质部的细胞壁明显增厚,出现明显的胶质纤维层;平均纤维长度、纤维素含量增加,表现出特有的理化特征。在拉弯处理早期阶段,4种内源激素在木质部中的含量呈现出不同的分布变化,推测这些激素的重新分布可能与光皮桦应拉木的形成有一定关系。%Objective]Reaction wood is one of the limiting factors for efficient cultivation and wood utilization of fast-growing timber species. There are various types of tension woods ( TWs) in Betula luminifera plantation,but the research on their characteristics and forming causes is absent. In this study,microscopic structure

  8. Vaccination for birch pollen allergy

    DEFF Research Database (Denmark)

    Jakobsen, C G; Bodtger, U; Poulsen, Lars K.

    2005-01-01

    Allergen-specific immunotherapy (SIT) is associated with increased levels of allergen-specific IgG in serum. However, it is not clear to what extent qualitative changes in the allergen binding capacity of IgG may be induced as well....

  9. 修枝高度对西南桦人工幼林生长的影响%Effects of pruning height on growth performance of young plantations of Betula alnoides

    Institute of Scientific and Technical Information of China (English)

    王春胜; 吴龙敦; 赵志刚; 林天龙; 郭俊杰; 沙二; 曾杰

    2012-01-01

    A pruning trail was conducted with series of pruning heights in five-year-old plantations of Betula alnoides, so as to assess the effect of pruning heights on growth performances of Betula alnoide and determine the optimal pruning height. Diameter at breast height (DBH), tree height and height of the lowest living branch were investigated in three years after pruning, and the volume was calculated by stem form factor at breast height. The results indicate that the increment of tree height and volume did not vary significantly under different treatments of pruning heights in three years after pruning. While DBH growth decreased apparently with increasement of pruning height and significant difference was seen between the control and other pruning treatments late in the first year after pruning, and there was no remarkable difference between them in the third year. Taking growth process and operational feasibility of pruning into consideration, the optimal pruning height was 6 meters for trees with height above 9.5 meters, and 5 meters for height above 8.0 meters, in other words, the pruning intensity was about 30%~40%. It not only had a weak effect on tree growth but also increased the production rate of high quality timber. The findings can provide scientific evidences for large-size knot-free timber production of B. alnoides.%以5年生西南桦人工林为研究对象,设置系列高度处理开展修枝试验,调查不同修枝处理当年及3年生西南桦的生长表现,从而探讨西南桦人工幼林的最佳修枝高度.研究结果显示:各修枝处理间西南桦树高及材积增长量在修枝后3年内均无显著差异,而修枝对西南桦当年的胸径生长有显著抑制作用,且随着修枝高度的增加而胸径增长量逐渐降低,而修枝后第3年各处理间胸径增长量差异不显著.综合考虑西南桦生长规律及修枝操作上的可行性,确定5年生时树高大于9.5 m的西南桦林木,其合适的修枝高度为6m

  10. Spatial Pattern Analysis of Individuals in Different Age-classes of Betula platyphylla in Huoshan Mountain of Shanxi Province%山西霍山白桦种群不同龄级立木的点格局分析

    Institute of Scientific and Technical Information of China (English)

    何艳华; 闫明; 武丽君; 张直峰; 毕润成

    2011-01-01

    Betula platyphylla is a pioneer plant and is distributed intensively in Huoshan mountain. One 50 m x 50 m quadrat was established in Qiliyu from which we recorded the DBH of each individual and the spatial points of all individuals were mapped. The data were analyzed by point pattern analysis. All individuals were divided into four DBH classes; DBH I (DBH≤ 7 cm);DBH Ⅱ (7 cm 21 cm).The results of this study showed; (1) The densities of four age-classes varied in the order: age-class n >age-class Ⅲ >age-class Ⅰ>age-class Ⅳ. The middle age-classes Ⅱ and Ⅲ had many more individuals than age-classes I and Ⅳ, which indicated that the population was currently in decline. (2) The individuals of all age-classes focused on clumping distribution in space, except the age-class Ⅰ. The feature of clumping distribution became more significant with increasing age. (3) The relationships between individuals in different age-classes were significantly correlated with each other on a small scale,but became non-significant with increasing scale,except for age-classes I and n ,age-classes Ⅱ and Ⅲ,and age-classes n and Ⅳ.%以山西霍山地区的先锋树种之一白桦( Betula platyphylla)为研究对象,在霍山七里峪林场典型地段设置一个50 m×50 m的样方,应用点格局分析方法对其不同龄级(Ⅰ级、Ⅱ级、Ⅲ级和Ⅳ级)个体的分布格局及相互关系进行了研究.结果表明:(1)白桦种群不同龄级的个体间密度也不相同,中间龄级Ⅱ级(7 cm< DBH≤14 cm)和Ⅲ级(14 cm <DBH≤21 cm)的密度较大,幼龄和老龄个体密度小,年龄结构为衰退型;(2)除Ⅰ级(DBH≤7 cm)外,其余3个龄级集群分布特征比较明显,且随着龄级的增加,集群特征有更明显的趋势;(3)除Ⅰ级和Ⅱ级、Ⅱ级和Ⅲ级、Ⅱ级和Ⅳ级(DBH >21 cm)之外,其余龄级间基本都是小尺度下负关联,并随尺度的增大关联性逐渐变得不显著.

  11. 白桦基因表达半定量RT-PCR中内参基因的选择%Selection of internal control genes in semi-quantitative RT-PCR in Betula platyphylla

    Institute of Scientific and Technical Information of China (English)

    戴超; 刘雪梅; 周菲

    2011-01-01

    In order to provide theoretical basis for researching lignin synthetic regulation, taking Betula platyphylla as investigated object, expression stability of four housekeeping genes in different tissues and periods were analyzed, which were 18S rRNA, Actin, Ubiquitin and Tubulin, respectively. The results showed that the expression of 18S rRNA, Actin and Ubiquitin were stable, and they could be used as internal control genes to analyze expression level of target genes in B. platyphylla. Tubulin was less stable, and could't be used as internal control genes to analyze expression of target genes.%为给调节木质素合成研究的开展提供理论基础,以白桦为研究对象,应用半定量RT-PCR技术分析白桦持家基因18S rRNA、肌动蛋自基因Actin、泛素基因Ubiquitin和微管蛋白基因Tubulin在白桦不同时期及不同部位中的表达.结果表明,18S rRNA,Actin及Ubiquitin基因在各样本间的表达无显著差异,说明这3个基因可作为校正白桦目标基因表达量的参照基因,而Tubulin基因在所有样品中的表达稳定性较差,不适宜作为白桦基因表达研究中的内参基因.

  12. Construction and analysis of a subtracted cDNA library of Betula platyphylla female inflorescence%白桦雌花序cDNA消减文库的构建及分析

    Institute of Scientific and Technical Information of China (English)

    魏继承; 杨传平; 王超; 姜静

    2005-01-01

    为研究白桦雌花序花期基因表达情况,以两天为间隔对其进行取样.基于SMART策略,通过RT-PCR,将源自最后时期样品的cDNA作为Driver cDNA,源自其他时期样品的cDNA作为Tester cDNA,构建抑制性消减文库.EST序列经blastX分析表明,该文库中的基因大致可以归为五类,分别同代谢、物质运输和信号转导、细胞周期、胁迫反应及调控相关.本文对基因表达同发育的关系做了探讨.%Female inflorescence of Betula platyphylla was sampled at an interval of each two days to analyze the background of gene expression in floral phase. On the basis of SMART strategy, the driver cDNA was obtained from total RNA of the last sample and the tester cDNA was from that of the others by RT-PCR which were subsequently used to construct a subtracted cDNA library. The result of the ESTs (expression sequence tags) blastX showed that the genes in the subtracted cDNA library could be mainly clustered into 5 groups related to metabolism, transportation and signal transduction, cell cycle, stress response, and regulation. The relationship between gene expression and development was also discussed.

  13. Solar UV-B effects on PSII performance in Betula nana are influenced by PAR level and reduced by EDU: results of a 3-year experiment in the High Arctic.

    Science.gov (United States)

    Albert, Kristian R; Mikkelsen, Teis N; Ro-Poulsen, Helge; Arndal, Marie F; Boesgaard, Kristine; Michelsen, Anders; Bruhn, Dan; Schmidt, Niels M

    2012-07-01

    The long-term and diurnal responses of photosystem II (PSII) performance to near-ambient UV-B radiation were investigated in High Arctic Betula nana. We conducted an UV exclusion experiment with five replicated blocks consisting of open control (no filter), photosynthetic active radiation and UV-B transparent filter control (Teflon), UV-B-absorbing filter (Mylar) and UV-AB-absorbing filter (Lexan). Ethylenediurea (EDU), a chemical normally used to protect plants against ozone injury, was sprayed on the leaves both in the field and in an additional laboratory study to investigate if EDU mitigated the effects of UV-B. Chlorophyll-a fluorescence induction curves were used for analysis of OJIP test parameters. Near-ambient UV-B radiation reduced across season maximum quantum yield (TR(o) /ABS = F(v) /F(m)), approximated number of active PSII reaction center (RC/ABS) and the performance index (PI(ABS)), despite improved leaf screening against UV-B with higher content of UV-B-absorbing compounds and a lower specific leaf area. EDU application counteracted the negative impact of UV-B on TR(o) /ABS, RC/ABS and PI(ABS) . This indicates that the mechanisms behind UV-B and ozone damage share some common features. The midday depression was present in all treatments, but TR(o) /ABS and PI(ABS) were persistently lower in near-ambient UV-B compared to UV-B reduction. The recovery phase was particularly impaired in near-ambient UV-B and interactive effects between treatment × hour raised TR(o) /ABS, RC/ABS and PI(ABS) higher in reduced UV-B compared to near-ambient UV-B. This demonstrates current solar UV-B to reduce the PSII performance both on a daily as well as a seasonal basis in this High Arctic species.

  14. 桦树花粉、大豆和苹果过敏原之间高免疫球蛋白E 相关性表明中国北方地区桦树花粉过敏患者很可能同时患有花粉-食物综合征%High correlation of specific IgE sensitization between birch pollen, soy and apple allergens indicates pollen-food allergy syndrome among birch pollen allergic patients in northern China

    Institute of Scientific and Technical Information of China (English)

    Guo-dong HAO; Yi-wu ZHENG; Zhi-xiang WANG; Xing-ai KONG; Zhi-jing SONG; Xu-xin LAI; Michael D SPANGFORT

    2016-01-01

    目的:研究中国北方地区桦树花粉过敏及花粉–食物过敏综合征。  创新点:国内首次研究花粉–食物过敏综合征,为中国北方地区此类患者的诊断和治疗提出了新思路。  方法:采集临床中过敏患者血清,检测桦树花粉及其主要过敏原特异性免疫球蛋白 E(IgE),同时检测大豆和苹果过敏原的特异性IgE,并评价其相关性。  结论:中国北方地区桦树花粉季节对此花粉过敏的患者有16.7%以上,主要是对桦树花粉第一组过敏原致敏。这些患者大多数同时对大豆和苹果的主要过敏原过敏,这种特异性IgE高相关性说明临床上存在花粉–食物过敏综合征。%Background: Birch pollen sensitization and associated pol en-food syndrome among Chinese al ergic patients have not been investigated. Methods: Sera from 203 al ergic patients from the northern part of China and col ected during February to July 2014 were investigated. Specific immunoglobulin E (IgE) against birch pol en extract Bet v and major birch pollen allergen Bet v 1 were measured using the ADVIA Centaur. The presence of major apple al ergen Mal d 1 and soy bean al ergen Gly m 4 specific IgE was measured by ImmunoCAP 100. Results:Among the 203 sera, 34 sera (16.7%) had specific IgE to Bet v and of these, 28 sera (82.4%) contained Bet v 1-specific IgE. Among the 28 sera with Bet v 1-specific IgE, 27 sera (96.4%) contained Mal d 1-specific IgE and 22 sera (78.6%) contained Gly m 4-specific IgE. Of the 34 Bet v-positive sera, 6 sera (17.6%) contained no specific IgE for Bet v 1, Mal d 1, or Gly m 4. Almost al Bet v-positive sera were donated during the birch pollen season. Conclusions:The prevalence of birch al ergy among patients visiting health care during pol en season can be as high as 16.7%in Tangshan City. The majority of Chinese birch al ergic patients are IgE-sensitized to the major birch pol en al ergen Bet v 1 as wel as to the

  15. Bio energy production in birch and hybrid aspen after addition of residue based fertilizers - establishment of fertilization trials; Bioenergiproduktion hos bjoerk och hybridasp vid tillfoersel av restproduktbaserade goedselmedel - etablering av goedslingsfoersoek

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, Gunnar (EkoBalans Fenix AB, Malmoe (Sweden))

    2009-03-15

    Sewage sludge and wood ashes could be used as fertilizers in order to increase forest tree production. In southern Sweden forest growth normally increases with approximately 10 % after ash recycling due to increased N and/or P availability. P is added with the ashes and the pH-increasing effect of the wood ash can lead to increased N net mineralization. Other positive effects of wood ash recycling are improved nutrient sustainability and less acid run-off water. Possible negative effects are heavy metal accumulation, if the content of one or more heavy metals of the recycled ash exceeds the heavy metal content of the harvested biomass, and nitrate leaching if the vegetation cannot take up nitrified N. It is important to evaluate the sustainability of fertilization systems based on residues such as sludge and wood ash. Wood ash does not contain N and the P concentration often is too low for the ashes to function as an NP fertilizer. Thus N and sometimes P must be added. Sludge is an interesting alternative. The main purpose of the project is to study sustainable production of forest bio energy in intensively cultivated birch and hybrid aspen stands. Another purpose is to establish experiments that can be used for long term studies and as demonstration objects. In the first few years the goal is to study the short term effects of residue based fertilization compared to conventional NPK fertilization on tree nutrient uptake, nutrient leaching, sustainability and economy. In the long term the goal is to design appropriate fertilization strategies in a residue based fertilization system for the intensive cultivation of birch and hybrid aspen without negative side effects such as large scale nutrient leaching. Four field experiments were established in 2008 and one additional experiment in hybrid aspen will be established in the spring of 2009. Elevated bud N and P concentrations after fertilization with both Ashes+N and NPK means good possibilities for future growth

  16. Integration of BpMADS4 on various linkage groups improves the utilization of the rapid cycle breeding system in apple.

    Science.gov (United States)

    Weigl, Kathleen; Wenzel, Stephanie; Flachowsky, Henryk; Peil, Andreas; Hanke, Magda-Viola

    2015-02-01

    Rapid cycle breeding in apple is a new approach for the rapid introgression of agronomically relevant traits (e.g. disease resistances) from wild apple species into domestic apple cultivars (Malus × domestica Borkh.). This technique drastically shortens the long-lasting juvenile phase of apple. The utilization of early-flowering apple lines overexpressing the BpMADS4 gene of the European silver birch (Betula pendula Roth.) in hybridization resulted in one breeding cycle per year. Aiming for the selection of non-transgenic null segregants at the end of the breeding process, the flower-inducing transgene and the gene of interest (e.g. resistance gene) that will be introgressed by hybridization need to be located on different chromosomes. To improve the flexibility of the existing approach in apple, this study was focused on the development and characterization of eleven additional BpMADS4 overexpressing lines of four different apple cultivars. In nine lines, the flowering gene was mapped to different linkage groups. The differences in introgressed T-DNA sequences and plant genome deletions post-transformation highlighted the unique molecular character of each line. However, transgenic lines demonstrated no significant differences in flower organ development and pollen functionality compared with non-transgenic plants. Hybridization studies using pollen from the fire blight-resistant wild species accession Malus fusca MAL0045 and the apple scab-resistant cultivar 'Regia' indicated that BpMADS4 introgression had no significant effect on the breeding value of each transgenic line.

  17. Thermal analysis of wood of the main tree species of Central Siberia

    Directory of Open Access Journals (Sweden)

    S. R. Loskutov

    2015-12-01

    Full Text Available Thermal decomposition of wood from coniferous and deciduous species of Siberia has been studied using thermogravimetry (TG and differential scanning calorimetry (DSC. The tree species were larch Larix sibirica Ledeb., Scots pine Pinus sylvestris L., spruce Picea obovata Ledeb., fir Abies sibirica Ledeb., Siberian pine Pinus sibirica Du Tour., birch Betula pendula Roth., and aspen Populus tremula L. Thermal analysis of wood samples was carried out under oxidative (air and inert (argon atmospheres from 25 to 700 °С at heating rates 10, 20, 40 °С • min–1 (TG/DTG and from 25 to 590 °С at heating rates 10, 40 °С • min–1 (DSC. The stages of thermal decomposition, the temperature intervals, the mass loss, the mass loss rate, the temperature of DTG/DSC peaks, and heating effects were determined for each tree species. The kinetic thermal degradation parameters of wood were obtained by the Broido and Ozawa–Flynn–Wall models. The wood of coniferous and deciduous species of Siberia was characterized on the base of analysis of activation energy values at various stages of thermal decomposition and the relations of activation energy on conversion level of wood substance of different tree species, and also the comparison of mass loss at the same stages of thermal destruction, heating effects, residual mass and other parameters of TG/DTG, DSC. In our opinion, the results of this work present interest for researchers and specialists in the field of forest pyrology, wood science, dendrochemistry.

  18. Secondary succession of trees in the dune landscape of the ‘Glinki’ long-term research area – analysis with GIS

    Directory of Open Access Journals (Sweden)

    Sewerniak Piotr

    2015-06-01

    Full Text Available The aim of the study was to present the main characteristics of the ‘Glinki’ research area together with results of the first measurements on tree number, density, distribution and species composition carried out in 2011. The research was conducted in a free-of-forest management part of the Toruń military area which is located in one of the biggest inland dune fields of Europe. The ‘Glinki’ research area was established in 2011 and consists of two plots (together 26.3 ha, which are in close proximity to each other. After the last fire in 1991, secondary succession has been the main factor shaping vegetation on both plots. For every plot, the location of all trees of at least 1 m height (560 in plot I and 292 in plot II was determined. These measurements were subjected to spatial analysis in ArcGIS 9.3 with special emphasis on the exposure of the dune slopes. The main tree species on both plots were Scots pine, Pinus sylvestris, and birch, Betula pendula, (82 % and 17 % of all trees respectively. Tree density 20 years after the last fire was very low (32 trees/ha, which mainly resulted from the lack of a sufficient source of seeds in the close vicinity of the plots during the first years after the fire. We also found that tree distribution was related to the main direction of seed inflow and land relief. Tree density was much higher on dune slopes with a northern exposure when compared to other slope exposures, which resulted from different site conditions on the different slopes.

  19. Characteristics of T-cell and B-cell immune respoonses to pollen allergens in Bulgarian patients with pollinosis

    Directory of Open Access Journals (Sweden)

    ZHIVKA KOSTOVA

    2015-12-01

    Full Text Available Characterization of the pollen allergens and identification of the main T-cell and B-cell epitopes is of crucial importance, since the clarification of the cellular and molecular mechanisms will allow long-term control of this type allergic diseases and development of safe immunotherapeutic medication. The objective of this study was to identify which pollen allergens are responsible for the T-cell activation in atopic patients with pollinosis and to determine whether the same allergens are responsible for the IgE-mediated reactions. Thirty-seven patients with pollinosis and thirteen non-allergic subjects were recruited. Peripheral blood samples were collected out of the pollen season. T-cell responses (IFN-γ production towards different pollen allergens and levels of pollen specific IgE and IgG in the sera were measured by ELISA. The T-cell reactivity in most patients was directed towards the grass pollen B1, tree pollen I and autumn pollen B5. 70% of the allergic individuals responded to allergens from Lolium perenne, 84% to Dactylis glomerata, 11% to Phleum pratense, 65% to Betula pendula and 70% to Taxus baccata. Elevated serum levels of specific IgE in the allergic patients (p<0.01 were measured against the tree pollen I and autumn pollen, which include widespread deciduous trees (birch, willow, poplar and yew and Artemisia absinthium, respectively. Our results show that the T-cell reactivity and antibody responses may be directed towards different or the same allergens. In addition, we propose that short synthetic peptides, which contain overlapping T- and B-cell epitopes can be used for specific immunotherapy treatment if they lack antibody recognition domains.

  20. Photosystem II cycle and alternative electron flow in leaves.

    Science.gov (United States)

    Laisk, Agu; Eichelmann, Hillar; Oja, Vello; Rasulov, Bakhtier; Rämma, Heikko

    2006-07-01

    Sunflower (Helianthus annuus L.) and tobacco (Nicotiana tabacum L.) were grown in the laboratory and leaves were taken from field-grown birch trees (Betula pendula Roth). Chlorophyll fluorescence, CO2 uptake and O2 evolution were measured and electron transport rates were calculated, J(C) from the CO2 uptake rate considering ribulose-1,5-bisphosphate (RuBP) carboxylation and oxygenation, J(O) from the O2 evolution rate, and J(F) from Chl fluorescence parameters. Mesophyll diffusion resistance, r(md), used for the calculation of J(C), was determined such that the in vivo Rubisco kinetic curve with respect to the carboxylation site CO2 concentration became a rectangular hyperbola with Km(CO2) of 10 microM at 22.5 degrees C. In sunflower, in the absence of external O2, J(O) = 1.07 J(C) when absorbed photon flux density (PAD) was varied, showing that the O2-independent components of the alternative electron flow to acceptors other than CO2 made up 7% of J(C). Under saturating light, J(F), however, was 20-30% faster than J(C), and J(F)-J(C) depended little on CO2 and O2 concentrations. The inter-relationship between J(F)-J(C) and non-photochemical quenching (NPQ) was variable, dependent on the CO2 concentration. We conclude that the relatively fast electron flow J(F)-J(C) appearing at light saturation of photosynthesis contains a minor component coupled with proton translocation, serving for nitrite, oxaloacetate and oxygen reduction, and a major component that is mostly cyclic electron transport around PSII. The rate of the PSII cycle is sufficient to release the excess excitation pressure on PSII significantly. Although the O2-dependent Mehler-type alternative electron flow appeared to be under the detection threshold, its importance is discussed considering the documented enhancement of photosynthesis by oxygen.

  1. Benthic fauna of extremely acidic lakes (pH 2-3)

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, G.G.

    2001-07-01

    The structure of the benthic invertebrate communities were investigated in terms of composition, abundance, and biomass from extremely acidic lakes with pH values from 2 to 3 in areas where coal was intensively mined in the Lusatian region in the eastern region of Germany. Benthic invertebrates colonisation on leaves and the breakdown rate processing of the three deciduous leaf: Betula pendula (birch), Fraxinus excelsior (ash), and Juglans regia (walnut) were investigated. Also, the main key-species of these acidic environments were investigated, in terms of description of pupal exuviae of Chironomus crassimanus and the feeding habit of this acid-resistant species through analysis of their gut content. The benthic food web in extremely acidic mining Lusatian lakes is very short in terms of species richness, trophic relationship, guilds and functional feeding groups. Collector-filters and scraper-grazers were absent in extremely acidic mining lakes (AML 107, AML 111 and AML 117). Shredders as Limnophyes minimus (Diptera, Chironomidae, Orthocladiinae) and Hydrozetes lacustris (Acari, Hydrozetidae) occurred in low abundance in AML 107 and AML 111, and it may be in response to slow leaf breakdown process in these ecosystems, except in AML 117 where the H. lacustris contributed most to ecosystems functioning via the processing of litter. Aquatic insects as Sialis lutaria (Megaloptera, Sialidae), Orectochilus villosus (Coleoptera, Gyrinidae), Coenagrion mercuriale (Odonata, Coenagrionidae), and Phryganeidae (Trichoptera) are the top-predators of these ecosystems. They did not depend on the level of pH in the lakes, but on the availability of food resources. (orig.)

  2. Effects of Drought Stress on Photosynthesis & Content of Osmoregulation Substance for Betula maximowicziana%干旱胁迫对真桦光合特性及渗透调节物质含量的影响

    Institute of Scientific and Technical Information of China (English)

    王晓冬; 李蕴峰; 刘宇明

    2012-01-01

    Using potted seedlings of Betula maximowicziana as material,an experiment was conducted to study the effects of drought stress on photosynthesis content of osmoregulation substance.Result shows that: net photosynthetic rate(P_n),transpiration rate,stomatal conductance(G_s) in seedlings of B.maximowicziana were significantly decreased by drought stress;decreased range increase with the increased levels of stress.At initial stage of the stress,G_s intercellular CO_2 content(C_i) decrease with the decrease of the P_n in group of slight or medium drought stress;photosynthesis reduction is mainly due to stomatal factor;for the metaphase or late stage,a decreasing P_n with higher C_i indicated that non-stomatal factor is the leading limitation.Soluble sugar in seedlings of B.maximowicziana increased under soil moisture stress,but non-significant change in soluble protein;soluble sugar is the main osmoregulation substance.%以真桦盆栽幼苗为试材,研究干旱胁迫对真桦叶片光合作用和渗透调节物质含量的影响。结果表明:干旱胁迫使真桦幼苗净光合速率、蒸腾速率和气孔导度显著降低,降低幅度随胁迫程度的加剧而加大。胁迫初期,轻度和中度干旱胁迫组真桦幼苗净光合速率降低的同时气孔导度和胞间CO2浓度同时降低,光合速率降低的主要原因是气孔因素;胁迫中期和后期,各干旱处理组光合速率降低的同时胞间CO2浓度均显著升高,非气孔限制是净光合速率降低的主要原因。真桦在干旱胁迫过程中,可溶性蛋白变化不显著,可溶性糖含量增加,为主要的渗透调节物质。

  3. Effects of Nitrogen Deposition on Soil Nitrogen Mineralization of Betula platyphylla Forest in Daxing ’ an Mountains%施氮量对大兴安岭白桦次生林土壤氮矿化的影响

    Institute of Scientific and Technical Information of China (English)

    包翔; 包秀霞; 刘星岑

    2015-01-01

    以大兴安岭白桦天然次生林为研究对象,分析施氮量对土壤氮矿化的影响。结果表明,白桦次生林土壤中铵态氮、硝态氮和有效氮质量分数在生长季间存在显著差异。总体上,土壤中有效氮素质量分数在7月份最高,5月份最低。白桦次生林土壤中铵态氮、硝态氮和有效氮质量分数均随着氮沉降量的增加而增加;同时氮沉降也显著增加了土壤氨化速率、硝化速率和氮矿化速率,其中氨化速率的增幅大于硝化速率的增幅。不同施氮处理下,净矿化速率与土壤有机碳质量分数间的相关性比与全氮质量分数间更为密切。%In a natural secondary forest of Betula platyphylla in Daxing’ an Mountains, we studied the effects of nitrogen deposi-tion on soil nitrogen mineralization.The contents of NH4-N, NO3-N and available N were significant differences among the growing seasons.Available N content was the highest on July and the lowest on May.The contents of NH4-N, NO3-N, available N, soil ammonification rate, nitrification rate and nitrogen mineralization rate were significantly increased with the increasing of N deposition.The ammonification rate of increase was greater than the nitrification rate.Under different N contents, the correlation ratio between the soil organic carbon and total N net mineralization rate was higher than total N.

  4. Effects of N exponential fertilization on nutrient loading and photosynthesis of Betula platyphylla seedlings%氮素指数施肥对白桦播种苗养分承载和光合作用的影响

    Institute of Scientific and Technical Information of China (English)

    郝龙飞; 刘婷岩; 张连飞; 贾斌英; 李宁; 李开隆

    2014-01-01

    为改善白桦苗木质量,本文采用常规施肥( CF)、指数施肥( EF)、1/2指数施肥( HEF)、2倍指数施肥( DEF)以及对照( CK)处理,研究容器苗中不同N施肥处理对白桦1年生播种苗生物量分配、养分含量动态和养分承载以及苗木叶片光合能力的影响。结果表明:1)生长结束后,EF处理提高了苗木生物量,同时改善了苗木根系生物量所占比例。 EF处理苗木总生物量较CK提高23.87%(P0.05)。 EF处理苗木叶面积高于CF处理14.3%(PDEF>HEF>CF>CK。 EF处理有效促进了苗木生物量积累,提高了苗木养分承载,同时明显提高了苗木体内P、K的养分利用效率,因此EF处理为最佳施肥方式。%In order to improve Betula platyphylla seedling quality, the biomass allocation, nutrient ( N, P, K) content dynamics, nutrient loading and leaf photosynthesis of B. platyphylla container seedlings under constant ( CF) , exponential ( EF) , half exponential ( HEF) and doubled exponential fertilization ( DEF) regimes and control (CK) were studied in the first year growing. Results showed that:1) at the end of the growing season, EF treatment improved the biomass of seedlings and the biomass proportion of root. The total biomass of seedlings under EF treatment was greater than that under CK ( P 0. 05) respectively. Meanwhile, seedling leaf area under EF treatment was greater than that under CF treatment in 14. 3%. 4) The concentration of N, P and N, K nutrient under 5 fertilization treatments was linear correlation. Exponential fertilization improved the P, K uptake efficiency ( EF>DEF>HEF>CF>CK) in seedlings. EF reffectively promoted biomass accumulation and improved nutrient loading, meanwhile, significantly increased P, K utilization. EF is the best fertilization regime for B. platyphylla seedlings.

  5. The Dynamics Response of Betula ermanii Population and Climate Change on Different Slopes Aspect of North Slope,Changbai Mountains%长白山北坡林线岳桦种群动态对气候变化响应的坡向分异

    Institute of Scientific and Technical Information of China (English)

    王晓东; 刘惠清

    2012-01-01

    To discover the relation between Betula ermanii population dynamics and climate change on treeline ecotone of Changbai Mountains,53 plots were selected on three different slope aspects(northeast,southeast,east slopes) through treeline ecotone on north slope of Changbai Mountains.Distributing character of the diameter-class(diameter at breast height(DBH)) structure of shrub and single-trunk forms were described by four aggregation indices.Trend analysis of distributing character was carried through by unitary linearity equations.Different reflection of the dynamics response of Betula ermanii population to climate change on different slope aspects was analyzed by stepwise regression and correlation analysis.The results are as follows:the results of trend analysis of the diameter-class distributing(slopes of equations are negative) shows the capacity expansion rate of shrub form is east slopes〉southeast slopes〉northeast slopes and that of single trunk form is northeast slopes〉east slopes〉southeast slopes.The population expansion is leapfrog and pulsatile from low to high(p〉0.01).The result of One-way ANOVA displays that daily mean temperature on three slopes are significant differences(p〈0.05) and the temperature change has synchronism.The results of correlation analysis between annual stem recruitment of Betula ermanii population and 14 ecological preferences of air temperature(1953-2008) show that the different response of population dynamics to climate change caused by different temperature on three slopes.The difference of climate change lead to different expansion of Betula ermanii population on different positions.%选取长白山北坡岳桦(Betula ermanii)苔原交错带3个不同坡向(东北坡、东南坡、东坡)的岳桦径级结构为研究对象,分析坡向在岳桦种群动态与气候变化之间关系的异同。结果表明:三坡向的岳桦种群扩张和气温高低存在明显差异。14个

  6. General Classification Handbook for Floodplain Vegetation in Large River Systems. Chapter 1 of Book 2, Collection of Environmental Data

    Science.gov (United States)

    2004-01-01

    tuberculatus WM Amorpha A. fruiticosa WMS Betula B. nigra FF, LF Bidens B. cernua, B. frondosa SMA Carex C. spp.1 SM Carya C. cordiformis, C. illinoensis LF...include pecan ( Carya ), hickory ( Carya ), river birch (Betula), sycamore (Platanus), and red/black oak (Quercus). This general class is most com- mon...near the edge of the floodplain, or out of the floodplain. This general class typi- cally consists of red or white oak (Quercus), hickory ( Carya

  7. Spatiotemporal dynamics of seed rain in natural forest of Betula alnoides in Jingxi County,Guangxi, China%广西靖西西南桦天然林种子雨的时空动态

    Institute of Scientific and Technical Information of China (English)

    郭俊杰; 赵志刚; 欧景莉; 沙二; 林开勤; 曾杰; 徐大平

    2012-01-01

    Aims Our objective was to study spatiotemporal dynamics of seed dispersal of Betula alnoides and analyze its correlation with wind speed and wind direction at community and individual levels. Methods Seed dispersal was investigated for a natural forest and an isolated tree of B. alnoides. We set seven sample lines 100 to 355 m long in or around the natural forest. One seed trap was placed every 5 m, and seeds were collected every two days. We set eight sample lines (east, southeast, south, southwest, west, northwest, north, northeast) around the isolated tree. Three seed traps were placed every 5 m from 0 to 50 m and every 10 m from 60 to 150 m, and seeds were collected each day. Wind speed and wind directions were measured at two sites. Seed rain density was calculated. Important findings The seed rain lasted 83 and 60 days at the community and individual levels, respectively. The starting, fastigium and subsiding stages of seed dispersal lasted 11,32 and 40 days for the community and 9, 25 and 26 days for the isolated individual. Seeds dispersed at the fastigium stage accounted for 83.1% and 68.7% of all seeds collected at the community and individual levels, respectively. Seed rain density was higher during the day than at night, and the highest seed rain density by day occurred at 12:00-16:00. At the individual level, seed rain density decreased with increasing distance from the maternal tree, and 79.6% of seeds were collected in the area of 0-30 m around the maternal tree. Seed rain density at the community level also decreased with longer distance from the forest edge, and 79.6% of seeds were collected in the area of 0-45 m around the forest edge. The seed rain density was significantly different among directions (p < 0.01), which was affected by wind direction. Seed rain density was also positively affected by wind speed (p < 0.05).%以一片西南桦(Betula alnoides)天然林和一个西南桦独立单株为研究对象,通过收集散种期内与林分或

  8. Isolation and Expression of Flowering Locus T (FT) Gene in Betula platyphylla%白桦开花位点Flowering Locus T(FT)基因的分离及其表达

    Institute of Scientific and Technical Information of China (English)

    马丽丽; 邱丽丽; 付扬威; 荆瑞瑞; 刘雪梅

    2012-01-01

    FT及其同源基因在促进植物成花和发育阶段转变过程中起重要作用.应用RT-PCR和RACE技术分离了白桦FT基因的cDNA,全长为928 bp,其开放阅读框为525 bp,编码174个氨基酸.预测的蛋白质分子量为19.6kDa,理论等电点为7.73.该预测蛋白序列含有保守的PEBP蛋白结构域,命名为BplFT,并在GenBank注册,登录号为JQ409561.该基因序列同其它16种植物的相似性为74% ~ 93%,其中与无花果(Ficus carica)的相似度最高为93%,与拟南芥(Arabidopsis thaliana)的相似度最低为74%,并构建了该基因序列的进化树.通过qRT-PCR的方法检测BplFT基因在白桦不同时期不同组织中的转录表达,在营养器官的表达高于花器官,成熟组织要高于幼嫩的组织,在成熟茎中的表达量最高,推测BplFT基因在成熟的营养器官发育中起重要作用,并可能参与调控次生细胞壁的形成.另外,选择了白桦雄花序突变体进行该基因的转录表达分析,该基因在突变体雌花序、雄花序、幼叶及幼茎中均为上调表达,预示着BplFT基因不仅仅参与营养组织发育,在花器官发育中也具有一定的作用.%Flowering Locus T ( FT) gene and its homologues play an important role in promotion flowering plants and changes in developmental stage. The full cDNA of FT gene was isolated from Betula platyphylla Suk. by methods of reverse transcription polymerase chain reaction ( RT-PCR) and 5' and 3' rapid amplification of cDNA ends (RACE) . Results showed that FT gene contains an open reading frame (ORF) of 525 bp encoding 174 amino acids. Molecular weight of the deduced protein of BplFT is 19. 6 kDa and the theoretical isoelectric point is 7.73. The FT conserved protein domain of PEBP was confirmed in the sequence, so the isolated gene was named as BplFT, and registered in GenBank with accession number JQ409561. The deduced amino acid sequence shared 74% -93% of identity with other sixteen plant species, the maximum

  9. Global atmospheric change and herbivory: Effects of elevated levels of UV-B radiation, atmospheric CO{sub 2} and temperature on boreal woody plants and their herbivores

    Energy Technology Data Exchange (ETDEWEB)

    Veteli, T.

    2003-07-01

    The aim of this study was to assess the effects of elevated ultraviolet-B radiation (UV-B, 280- 320 nm), atmospheric CO{sub 2}, temperature and soil nitrogen level on the growth and chemical quality of boreal deciduous woody plants and on performance of the herbivorous insects feeding on them. Eggs and larvae of Operophtera brumata (L.) (Lepidoptera, Geometridae) were subjected to elevated UV-B radiation in the laboratory. Two willow species, Salix phylicifolia L. (Salicaceae) and S. myrsinifolia Salisb., were grown in an UV-B irradiation field where the responses of both plants and their herbivorous insects were monitored. S. myrsinifolia, Betula pendula Ehrh. (Betulaceae) and B. pubescens Roth. were subjected to elevated CO{sub 2} and temperature and different fertilisation levels in closed-top climatic chambers. To assess the indirect effects of the different treatments, the leaves of experimental willows and birches were fed to larvae of Phratora vitellinae (L.) (Coleoptera, Chrysomelidae) and adults of Agellastica alni L. in the laboratory. Elevated UV-B radiation significantly decreased the survival and performance of eggs and larvae of O. brumata. It also increased concentrations of some flavonoids and phenolic acids in S. myrsinifolia and S. phylicifolia, while the low-UV-B- absorbing phenolics, e. g. condensed tannins, gallic acid derivatives and salicylates, either decreased or remained unaffected. Both the height growth and biomass of one S. phylicifolia clone was sensitive to elevated levels of UV-B radiation. Abundance of adults and larvae of a willow- feeding leaf beetle, P. vitellinae, was increased under elevated UV-B; but this did not lead to increased leaf damage on the host plants. There were no significant differences in performance of the larvae feeding on differentially treated willow leaves, but adult A. alni preferred UV-B-treated leaves to ambient control leaves. Elevated CO{sub 2} and temperature significantly increased the height growth

  10. Comparison on soil microbial activities and bacterial diversity between Betula alnoides and Pinus massoniana plantations in red soil region, China%南方红壤区西南桦和马尾松人工林土壤微生物活性及细菌多样性比较

    Institute of Scientific and Technical Information of China (English)

    杨尚东; 吴俊; 谭宏伟; 刘永贤; 熊柳梅; 周柳强; 谢如林; 黄国勤; 赵其国

    2014-01-01

    目前,西南桦(Betula alnoides)和马尾松(Pinus massoniana)均是广西红壤区大规模种植的人工林树种。为了分析和评价这两个树种对土壤肥力和生态质量的影响,本文采用了稀释平板法和氯仿熏蒸提取法等传统方法分析了两种人工林土壤可培养微生物数量、微生物量碳、微生物量氮、涉及土壤碳、氮、磷循环相关酶活性等表征微生物活性的指标。同时,采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术分析了两种人工林土壤细菌多样性。结果表明,西南桦人工林土壤中可培养真菌数量与马尾松人工林虽无明显差异,但可培养细菌和放线菌数量均明显高于相应的马尾松人工林。土壤中β-葡萄糖苷酶、磷酸酶和蛋白酶活性在两种人工林之间虽无明显差异,但西南桦人工林各土层土壤的微生物生物量碳、氮指标均优于对应的马尾松林,表现出比马尾松更优的生态效果。此外,西南桦人工林土壤中各土层细菌多样性指数(Shannon-Wiener index)均高于相应的马尾松人工林土层。综上,比马尾松相比,西南桦是更有利于提高红壤区土壤肥力和维持林地土壤生态质量的造林树种。%In recent years, Betula alnoides and Pinus massoniana has been planted on large scale in red soil region of Guangxi Province. To clarify their influences on soil fertility and ecological quality in plantations, a comparative study was conducted to analyze the spatial variability of soil fertility and biological properties using the methods of dilution-plates and chloroform fumigation extraction. Meanwhile, the soil bacterial diversity in plantations was also analyzed by the method of polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that the numbers of culturable bacteria and antinomycetes in the Betula alnoides plantation were significantly higher than

  11. Tissue Culture of Endangered Plant Betula microphylla var.paludosa and Its Pilotscale Experiment in Shanghai Area%濒危植物沼泽小叶桦组织培养技术及其在上海地区的中试

    Institute of Scientific and Technical Information of China (English)

    张群

    2012-01-01

    为快速获得大量沼泽小叶桦苗,通过对茎尖进行丛生芽诱导、生根、移栽,成功获得了沼泽小叶桦组培苗.研究了沼泽小叶桦外植体不同灭菌方法、培养基等因素对沼泽小叶桦组培的影响.结果表明,10%次氯酸钠作为外植体消毒剂优于0.1%升汞,适宜的丛生芽诱导增殖培养基为MS+0.6 mg/L 6-BA+3%蔗糖+O.7%琼脂,最佳生根培养基为MS+3%蔗糖+0.7%琼脂.无菌苗移栽在蛭石∶珍珠岩∶草炭=3∶3∶4的介质中,成活率达100%,生长良好.%A large number of seedlings of Betula microphylla var. Paludosa was achieved by inducing adventitious buds, rooting and transferring. The effects of different disinfection methods, culture medium and proportions of transferring media on explants Betula microphylla var. Paludosa were investigated. The result showed that the disinfection effect of 10% sodium hypochlorite was better than 0.1% mercuric chloride. The appropriate culture medium for adventitious bud inducing proliferation was MS + 0. 6 mg/L 6-BA + 30 g/L sucrose + 7 g/L agar. The optimized rooting medium was MS + 30 g/L sucrose + 7 g/ L agar. The most effective medium for livability of asepsis sprout transferring of Betula microphylla var. Paludosa was vermiculite : per lite : peat = 3 : 3 : 4, and its surviving rate reached 100%. Tissue culture seedlings grew well in Shanghai area.

  12. 光皮桦茎叶cDNA文库构建及部分EST序列SSR分析%Library construction of cDNA and SSR analysis of partial ESTs for stem and leaf of Betula luminifera

    Institute of Scientific and Technical Information of China (English)

    张敏; 黄华宏; 林二培; 周厚君; 王亚辉; 童再康

    2012-01-01

    A cDNA library of stem and leaf from Betula luminifera was constructed.The primary titer of cDNA library was about 1.5×106 pfu/mL,its recombinant efficiency reached 97.3%,and the size of insert DNA fragments ranged from 0.5 to 3.0 kb,with an average of 1.3 kb.The results indicated that it was a higher-quality cDNA library,and could be used in gene cloning and gene expression profile analysis.Distribution and frequency of SSRs were analyzed in 224 non-redundant ESTs from B.luminifera cDNA library,using online searching software.The results showed that 60 SSRs distributed in 47 EST sequences,accounting for 26.80% of all ESTs.Dinucleotide would be the major repeat types,accounting for 70.00% of the total number of acquired SSRs.The tri-nucleotide and tetra-nucleotide repeats accounted for 28.30% and 1.70% respectively.This research might lay the foundation for designing the targeted EST-SSR primers and genetic diversity analysis by mining the information of EST-SSR loci in B.luminifera EST sequence data.%以光皮桦茎叶组织为材料,构建了cDNA文库。初级文库滴度为1.5×106pfu/mL,重组率达97.3%,插入片段大小在0.5~3.0kb之间,平均长度约为1.3kb,表明所构建的文库质量较高,可用于后续基因克隆及基因表达谱的研究。利用微卫星查找软件对获得的224条EST序列进行微卫星位点搜寻及其丰度、分布比较,发现47条序列含微卫星位点60个,占全部EST序列的26.80%;在所有SSRs中二碱基重复最多,为42个,占总数的70.00%,含三、四碱基重复分别占总数的28.30%和1.70%。通过对光皮桦EST序列中微卫星位点信息的发掘分析,为有针对性地设计EST-SSR引物、进行遗传多样性分析奠定了基础。

  13. ALLOZYME DIVERSITY IN NATURAL POPULATIONS OF BETULA ALNOIDES FROM GUANGXI, CHINA%广西区西南桦天然居群遗传多样性的研究

    Institute of Scientific and Technical Information of China (English)

    曾杰; 王中仁; 周世良; 郑海水; 白嘉雨

    2003-01-01

    以采自广西区11个西南桦(Betula alnoides)天然居群的种子培育出的幼苗为材料,取其嫩叶开展21种酶系统的水平切片淀粉凝胶电泳实验,运用作者改进的Tris-马来酸提取缓冲液 (含30%PVP 40 000和1%2-巯基乙醇),筛选出AMP(氨基肽酶Aminopeptidase)、FBA(果糖二磷酸酶Fructose-bisphosphate aldolase)、GDH(谷氨酸脱氢酶Glutamate dehydrogenase)、G6PD(6-磷酸葡萄糖脱氢酶Glucose-6-phosphate dehydrogenase)、IDH(异柠檬酸脱氢酶Isocitrate dehydrogenase)、MDH(苹果酸脱氢酶Malate dehydrogenase)、PGD(6-磷酸葡萄糖酸脱氢酶Phosphogluconate dehydrogenase)、PGI(磷酸葡萄糖异构酶Phosphoglucoisomerase)、PGM(磷酸葡萄糖变位酶Phosphoglucomutase)和SKD(莽草酸脱氢酶Shikimate dehydrogenase)等10种酶,获得了清晰且可重复的酶谱.通过谱带遗传分析确定了15个位点,其中有6个单态位点,9个多态位点 (0.95标准),具40个等位基因.在居群水平上,西南桦的多态位点百分数 (P) 为55.2%,平均每个位点的等位基因数 (A) 为2.00,平均预期杂合度 (He) 为0.204.均超过Hamrick (1992)等提出的远交风媒木本植物的平均值(53.0%,1.84%和0.154),表明西南桦的遗传变异水平高.在11个西南桦居群内,实际杂合度 (Ho)均高于预期杂合度,出现杂合子过量,可能存在利于杂合子的自然选择.西南桦遗传多样性与地理位置相关不显著.居群2 (靖西地州)、5 (平果海城)、9 (田林者苗) 包含绝大部分的等位基因,而且具较高的遗传多样性,应加以保护和管理,作为其基因资源就地保存的基地.本研究解决了以西南桦嫩叶为材料进行等位酶分析的关键技术,为进一步开展西南桦乃至桦木属树种的遗传结构和遗传多样性等提供了技术基础;同时掌握了西南桦天然居群的遗传多样性现状,为其有效保护和合理经营以及西南桦的遗传改良提供了理论依据.

  14. Trend of earlier spring in central Europe continued

    Science.gov (United States)

    Ungersböck, Markus; Jurkovic, Anita; Koch, Elisabeth; Lipa, Wolfgang; Scheifinger, Helfried; Zach-Hermann, Susanne

    2013-04-01

    Modern phenology is the study of the timing of recurring biological events in the animal and plant world, the causes of their timing with regard to biotic and abiotic forces, and the interrelation among phases of the same or different species. The relationship between phenology and climate explains the importance of plant phenology for Climate Change studies. Plants require light, water, oxygen mineral nutrients and suitable temperature to grow. In temperate zones the seasonal life cycle of plants is primarily controlled by temperature and day length. Higher spring air temperatures are resulting in an earlier onset of the phenological spring in temperate and cool climate. On the other hand changes in phenology due to climate change do have impact on the climate system itself. Vegetation is a dynamic factor in the earth - climate system and has positive and negative feedback mechanisms to the biogeochemical and biogeophysical fluxes to the atmosphere Since the mid of the 1980s spring springs earlier in Europe and autumn is shifting back to the end of the year resulting in a longer vegetation period. The advancement of spring can be clearly attributed to temperature increase in the months prior to leaf unfolding and flowering, the timing of autumn is more complex and cannot easily be attributed to one or some few parameters. To demonstrate that the observed advancement of spring since the mid of 1980s is pro-longed in 2001 to 2010 and the delay of fall and the lengthening of the growing season is confirmed in the last decade we picked out several indicator plants from the PEP725 database www.pep725.eu. The PEP725 database collects data from different European network operators and thus offers a unique compilation of phenological observations; the database is regularly updated. The data follow the same classification scheme, the so called BBCH coding system so they can be compared. Lilac Syringa vulgaris, birch Betula pendula, beech Fagus and horse chestnut Aesculus

  15. Based Intrusion Detection Model Poly Type BIRCH Algorithm Design and Realization%基于聚类型BIRCH算法进行数据挖掘的入侵检测模型设计与实现

    Institute of Scientific and Technical Information of China (English)

    吴春琼

    2013-01-01

      随着网络时代的发展,信息安全己成为系统运行时的重要组成部分。传统意义上的防火墙无法抗击新网络入侵,不能系统提供有效的保护。本文介绍了入侵检测以及分类,数据挖掘中的聚类模式以及BIRCH算法,并分析它们的特性。最后使用KDD CUP 1999数据库进行模拟运行测试程序,并给出结果。%With the development of the Internet age, information security has become an important part of the system is running. The firewall can not fight against the new network intrusion in the traditional sense, can not provide effective protection. This article describes the intrusion detection and classification, data mining, clustering mode and BIRCH al-gorithm, and analyze their characteristics. Finally, use the KDD CUP 1999 database simulation run the test program, and gives the results.

  16. Speciation of Mg, Mn and Zn in extracts of medicinal plants.

    Science.gov (United States)

    Weber, Günther; Konieczyński, Paweł

    2003-04-01

    Aqueous extracts of birch leaves ( folium Betulae), peppermint leaves ( folium Menthae), sage leaves ( folium Salviae), valerian roots ( radix Valerianae), and dandelion roots ( radix Taraxaci) are analysed for the three essential elements magnesium, manganese and zinc. Ultrafiltration reveals that 60-100% of these metals are present as low molecular weight species (complexation.

  17. National Wetland Plant List Indicator Rating Definitions

    Science.gov (United States)

    2012-07-01

    cut grass), Acorus americanus (sweetflag), Carex aquatilis (leafy tussock sedge ), and Toxicodendron vernix (poison sumac). FACW (Facultative Wetland...where water saturates the soils or floods the soil surface at least seasonally. Examples include Carex scoparia (broom sedge ), Aconitum columbianum...Ambrosia artemisifolia (annual ragweed), Betula papyrifera (paper birch), Carex eburnea (bristle-leaf sedge ), Carya ovata (shag-bark hickory), Elymus

  18. Comparative measurements of transpiration an canopy conductance in two mixed deciduous woodlands differing in structure and species composition

    DEFF Research Database (Denmark)

    Herbst, Mathias; Rosier, Paul T.W.; Morecroft, Michael D.;

    2008-01-01

    Transpiration of two heterogeneous broadleaved woodlands in southern England was monitored by the sap flux technique throughout the 2006 growing season. Grimsbury Wood, which had a leaf area index (LAI) of 3.9, was dominated by oak (Quercus robur L.) and birch (Betula pubescens L.) and had a cont...

  19. Cottonwoods of the Midwest: A Community Profile

    Science.gov (United States)

    2008-05-01

    Bitternut hickory Carya cordiformis X X Pignut hickory Carya glabra X Pecan Carya illinoensis X Shellbark hickory Carya lacinios X Shagbark...rugosa X Pawpaw Asimina triloba X River birch Betula nigra X American hornbeam Carpinus caroliniana X Water hickory Carya aquatica X...hickory Carya ovata X Mockernut hickory Carya tomentosa X Sugarberry Celtis laevigata X Hackberry Celtis occidentalis X X Eastern redbud

  20. A Regional Guidebook for Applying the Hydrogeomorphic Approach to the Functional Assessment of Forested Wetlands in Alluvial Valleys of East Texas

    Science.gov (United States)

    2010-10-01

    hickory Carya illinoensis pecan Carya spp. hickory Celtis laevigata sugarberry Celtis occidentalis hackberry Cephalanthus occidentalis...abundance were deciduous holly and red maple. Matos and Rudolph (1985) recorded overcup oak, laurel oak, sweetgum, black gum, water hickory ( Carya ...switchcane Berchemia scandens supplejack Betula nigra river birch Campsis radicans trumpet creeper Carpinus caroliniana ironwood Carya aquatica water

  1. Climate Change Impact on Duration of Vegetative Period of Five Deciduous Tree Species

    Directory of Open Access Journals (Sweden)

    Asta Šimatonytė

    2009-12-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The air temperature is directly linked to the plant growth season, affecting the timing of the start and the end of the vegetative period and its duration. The aim of this study was to analyse the impact of changing climatic parameters on the duration of the vegetation period in 1956-2008 of five deciduous tree species (oak - Quercus robur L., maple - Acer platanoides L., lime - Tilia x vulgaris Hayne, birch - Betula pendula Roth. and ash - Fraxinus excelsior L. growing in Kaunas Botanical Garden of Vytautas Magnus University. The duration of the vegetative period (number of days was calculated between the dates of the beginning of bud swell and the end of leaf fall phenophases. Mean length of the vegetative period in 1956-2008 of observed tree species varied from 186 for ash to 214 days for birch. The beginning of the bud swelling phenophase advanced on average from 1 (oak to 14 days (ash in 1956-2008. The beginning of the bud swelling phenophase was significantly related to the temperature of February (for lime, birch and ash and March (for all species. The end of the leave fall phenophase was delayed on average from 3 (birch to 25 days (maple in 1956-2008. In most cases, the end of a leave fall phenophase

  2. Relationship Between Climate and Tree-ring Chronology of Betula ermanii on Tree-line in North Slope of the Changbai Mountains%长白山北坡林线处岳桦年轮年表及其与气候的关系

    Institute of Scientific and Technical Information of China (English)

    王晓明; 赵秀海; 高露双; 姜庆彪

    2012-01-01

    运用相关函数及响应分析等树木年轮气候学方法,研究了长白山北坡林线处岳桦(Betula ermanii径向生长及其与气候的关系.结果表明,林线处岳桦年轮宽度年表具有较强的气候敏感性.其径向生长与上年7月和当年3月的温度显著负相关(P<0.05),与上年9月和当年7月的温度显著正相关;同时与上年6月降水量显著正相关.与季节性气候因子的响应分析表明,岳桦径向生长与当年春季(1~3月)和当年生长季前(4、5月)的平均温度呈显著负相关,与当年生长季前的平均最高温度显著正相关,与降水量的相关关系不显著.利用多元逐步回归方法模拟了岳桦年轮宽度指数与气候因子间的关系,并据此预测在温度和降水增加的背景下,林线处岳桦径向生长将降低14.8%.%The tree-ring width chronologies were developed in north slope of the Changbai Mountains to analyze the Betula ermanii radial growth-climate relationships through dendrochronological methods including correlation and response analysis. The results showed that the radial growth of Betula ermanii exhibited a significantly nagative correlation with monthly temperature of both previous July and current March (P < 0.05), a significantly positive correlation with monthly temperature of previous September and current July, and a significantly positive correlation with monthly total precipitation of previous June. Besides, the analysis of response toseasonally climatic factors showed that the tree-ring growth of B. Ermanii had a significantly negative correlation with mean temperature of current spring (January to March), a significantly negative correlation with mean temperature of the period before current growth season (April and May), and a significantly positive correlation with mean maximum temperature of the period before current growth season. But it showed no significant correlation with seasonally precipitation. Furthermore, the

  3. The role of forest floor and trees to the ecosystem scale methane budget of boreal forests

    Science.gov (United States)

    Pihlatie, Mari; Halmeenmäki, Elisa; Peltola, Olli; Haikarainen, Iikka; Heinonsalo, Jussi; Santalahti, Minna; Putkinen, Anuliina; Fritze, Hannu; Urban, Otmar; Machacova, Katerina

    2016-04-01

    Boreal forests are considered as a sink of atmospheric methane (CH4) due to the activity of CH4 oxidizing bacteria (methanotrophs) in the soil. This soil CH4 sink is especially strong for upland forest soils, whereas forests growing on organic soils may act as small sources due to the domination of CH4 production by methanogens in the anaerobic parts of the soil. The role of trees to the ecosystem-scale CH4 fluxes has until recently been neglected due to the perception that trees do not contribute to the CH4 exchange, and also due to difficulties in measuring the CH4 exchange from trees. Findings of aerobic CH4 formation in plants and emissions from tree-stems in temperate and tropical forests during the past decade demonstrate that our understanding of CH4 cycling in forest ecosystems is not complete. Especially the role of forest canopies still remain unresolved, and very little is known of CH4 fluxes from trees in boreal region. We measured the CH4 exchange of tree-stems and tree-canopies from pine (Pinus sylvestris), spruce (Picea abies) and birch (Betula pubescens, Betula pendula) trees growing in Southern Finland (SMEAR II station) on varying soil conditions, from upland mineral soils to paludified soil. We compared the CH4 fluxes from trees to forest-floor CH4 exchange, both measured by static chambers, and to CH4 fluxes measured above the forest canopy by a flux gradient technique. We link the CH4 fluxes from trees and forest floor to physiological activity of the trees, such as transpiration, sap-flow, CO2 net ecosystem exchange (NEE), soil properties such as temperature and moisture, and to the presence of CH4 producing methanogens and CH4 oxidizing methanotrophs in trees or soil. The above canopy CH4 flux measurements show that the whole forest ecosystem was a small source of CH4 over extended periods in the spring and summer 2012, 2014 and 2015. Throughout the 2013-2014 measurements, the forest floor was in total a net sink of CH4, with variation

  4. 粤北西南桦种源试验林星天牛危害分析与早期综合评价%Hazard Analysis of Anoplophora chinensis and Early Comprehensive Selection of Betula alnoides Provenances in Northern Guangdong Province

    Institute of Scientific and Technical Information of China (English)

    赵志刚; 张朝斌; 丘英华; 郭俊杰; 何永佳; 翁启杰; 曾杰

    2011-01-01

    Betula alnoides Buch. -Ham. Ex D. Don is a fast-growing and precious tree species in tropical and warm subtropical regions. The wood borer damage has recently been one of key factors limiting the large-scale expansion of B. Alnoides plantations. A trial including 26 provenances and 322 families were established at Shaoguan State-owned Forest Farm in northern Guangdong Province, which were suffered from heavy damage of wood borers within two years after planted. The growth performance and resistances to wood borers of B. Alnoides were investigated for the purpose of early selection of germplasm. The results showed that there were significant differences among prove-nances in height and base diameter (P 0. 05) , and the mean attack rates for one-year-old and two-year-old B. Alnoides trees were 48. 21% and 36. 27% , respectively. Early selection of B. Alnoides provenance was carried out based on its growth performance and the attack rate by the wood borers. These findings could be contributive to understand the occurrence of A. Chinensis, protect from its damage, and provide evidences to select germplsm of B. Alnoides with good growth performance and strong resistance to A. Chinensis in northern Guangdong and surrounding areas with similar environment.%西南桦(Betula alnoides Buch.-Ham.Ex D.Don)是我国热带南亚热带地区的一个优良乡土阔叶树种[1-2],在云南、广西、广东等地被广泛应用于珍贵用材林基地建设,是该区域造林面积最大的乡土阔叶树种之一[2].西南桦木材可用于制作木地板、高档家具以及室内装饰等[3],而且人工林具维持生物多样性、涵养水源、保持地力以及较高的固碳能力等优良生态特性[2],在用材林、生态公益林等建设中具有重要的地位和发展潜力.经过二十多年的研究,西南桦的良种选育和栽培技术已取得显著成果,促进了人工林的发展,但在西南桦推广种植过程中,尤其是近几年来,蛀干害虫的

  5. Behavior of Sr-90 and transuranic elements in three areas in Finland[Radioecology

    Energy Technology Data Exchange (ETDEWEB)

    Ikaeheimonen, T.K.; Vartti, V.P.; Ilus, E. [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland)

    2006-04-15

    The study was carried out in three areas (both terrestrial and aquatic): in the Maenttae area in Central Finland and in the environs of the Loviisa and Olkiluoto Nuclear Power Plants. The highest Sr-90 concentrations were found in Ebilobium angustifolium, being 70 - 90 Bq/kg d.w., and Empetrum nigrum, 15 - 60 Bq/kg d.w. Concentrations of more than 10 Bq/kg d.w. were also detected in leaves of birch (Betula pendula), in berries of Empetrum nigrum and in ferns (Dryopteris carthusiana, Dryopteris expansa, Polypodium vulgare). The Sr-90 concentrations in mushrooms were less than 10 Bq/kg d.w. and varied considerably from one species to another. The concentrations of Pu-239,240 were below the detection limits in mushrooms and berries. Detectable amounts of Pu-239,240 were found in ferns. Am-241 was detected in ferns, but also in a Cantharellus tubaeformis sample and in Calluna vulgaris, in which the Pu-239,240 concentrations were below the detection limits. The highest concentrations of Sr-90 in fresh water environment were detected in shells and flesh of freshwater clam, Anodonta sp., and in marine environment in Saduria entomon and Macoma balthica. In Anodonta sp. (both shells and flesh), also Pu-239,240 and Am-241 were detected. Pu-239,240 was detectable in almost all the marine samples. Concentration factors (CF) of Pu-239,240 were roughly at the same level or greater than those of Sr-90, especially in the marine environment. Best indicator organism for Sr in the fresh water environment was Anodonta sp., and then Nuphar lutea (CFs 10{sup 3} - 10{sup 4}); and Macoma balthica and Fucus vesiculosus in the marine environment. Roots of Nymphaea candida and flesh of Anodonta sp. accumulated best Pu-239,240 in fresh water environment; The CFs of Pu-239,240 were greater in the marine environment compared to those in fresh water environment. Phytoplankton and periphyton accumulate most efficiently Pu-239,240 in the marine environment. The behavior of plutonium and americium

  6. DO3SE modelling of soil moisture to determine ozone flux to European forest trees

    Directory of Open Access Journals (Sweden)

    M. Schaub

    2011-12-01

    Full Text Available The DO3SE (Deposition of O3 for Stomatal Exchange model is an established tool for estimating ozone (O3 deposition, stomatal flux and impacts to a variety of vegetation types across Europe. It has been embedded within the EMEP (European Monitoring and Evaluation Programme photochemical model to provide a policy tool capable of relating the risk of vegetation damage to O3 precursor emission scenarios for use in policy formulation. A key limitation of regional flux-based risk assessments so far has been the approximation that soil water deficits are not limiting O3 flux due to the unavailability of evaluated methods for modelling soil water deficits and their influence on stomatal conductance (gsto, and ultimately O3 flux. This paper describes the development and evaluation of a method to estimate soil moisture status and its influence on gsto for a variety of forest tree species. The soil moisture module uses the Penman-Monteith energy balance method to drive water cycling through the soil-plant-atmosphere system and empirical data describing gsto relationships with pre-dawn leaf water status to estimate the biological control of transpiration. We trial four different methods to estimate this biological control of the transpiration stream, which vary from simple methods that relate soil water content or potential directly to gsto to more complex methods that incorporate hydraulic resistance and plant capacitance that control water flow through the plant system. These methods are evaluated against field data describing a variety of soil water variables, gsto and transpiration data for Norway spruce (Picea abies, Scots pine (Pinus sylvestris, birch (Betula pendula, aspen (Populus tremuloides, beech (Fagus sylvatica and holm oak (Quercus ilex collected from ten sites across Europe and North America. Modelled estimates of these variables show consistency with observed data when applying the simple empirical methods, with the timing and magnitude of

  7. Habitat Characteristics of Bracken-Covered Areas Intended for Afforestation in Ličko Sredogorje

    Directory of Open Access Journals (Sweden)

    Zvonko Seletković

    2013-12-01

    birch (Betula pendula Roth., Common spruce (Picea abies Karst., Eastern white pine (Pinus strubus L., Black pine (Pinus nigra subsp. austriaca Asch i Gr., Common pine (Pinus sylvestris L. and European trembling aspen (Populus tremula L. can be established.

  8. Modeling and analysis of the vertical roots distribution in levees - a case study of the third Rhone correction

    Science.gov (United States)

    Gianetta, Ivan; Schwarz, Massimiliano; Glenz, Christian; Lammeranner, Walter

    2013-04-01

    In recent years the effects of roots on river banks and levees have been the subject of major discussions. The main issue about the presence of woody vegetation on levees is related to the possibility that roots increase internal erosion processes and the superimposed load of large trees compromise the integrity of these structures. However, ecologists and landscape managers argue that eliminating the natural vegetation from the riverbanks also means eliminating biotopes, strengthening anthropisation of the landscape, as well as limiting recreations areas. In the context of the third correction of the Rhone in Switzerland, the discussion on new levee geometries and the implementation of woody vegetation on them, lead to a detailed analysis of this issue for this specific case. The objective of this study was to describe quantitatively the processes and factors that influence the root distribution on levees and test modeling approaches for the simulation of vertical root distribution with laboratory and field data. An extension of an eco-hydrological analytic model that considers climatic and pedological condition for the quantification of vertical root distribution was validated with data provided by the University of Vienna (BOKU) of willows' roots (Salix purpurea) grown under controlled conditions. Furthermore, root distribution data of four transversal sections of a levee near Visp (canton Wallis, Switzerland) was used to validate the model. The positions of the levee's sections were chosen based on the species and dimensions of the woody vegetation. The dominant species present in the sections were birch (Betula pendula) and poplar (Populus nigra). For each section a grid of 50x50 cm was created to count and measure the roots. The results show that vertical distribution of root density under controlled growing conditions has an exponential form, decreasing with increasing soil depth, and can be well described by the eco-hydrological model. Vice versa, field

  9. Clone and Analysiso f ReverseT ran script ase of Ty1-copia-like Retrotransposon s in Betula platyphly la under Sodi-um Nitroprusside (SNP) and Methyl Jasmonate (MeJA) Treatment%硝普钠(SNP)和茉莉酸甲酯(MeJA)诱导的白桦Ty1-copia类逆转座子的克隆及分析

    Institute of Scientific and Technical Information of China (English)

    梁楠松; 曾凡锁; 李博; 郭梁; 詹亚光

    2013-01-01

    We designed the primers of reverse transcriptase according to the conserved domains of the Ty1-copia retrotransposons reverse transcriptase.We obtained several fragments of reverse transcriptase from callus of birch by using improved RT-PCR.Eleven and nine fragments were amplified from callus of birch treated by sodium nitroprusside ( SNP) and methyl jasmonate (MeJA), respectively.The length of 21 reverse transcriptase sequences (named Bprt 1-21) is from 205 to 290 bp, with the consistency of 71.93%, the heterogeneity of from 1.1% to 50.9% and the heterogeneity of amino acid se-quences of from 0.0% to 57.1%.The sequences from birch treated by SNP or MeJA are clustered, respectively.The transcription of Ty1-copia-like retrotransposons can be activated by different signals.The analysis of the phylogenetic tree of reverse transcriptase of Ty1-coip a-like retrotransposons between birch and apple revealed each of the reverse transcripta-ses are clustered together, but the evolutional relationship between Bprt9, Bprt11 and DQ410750 are closer.Bprt15, Bprt19, DQ410751 and DQ410753 are clustered together.Therefore, the horizontal transmission can exist in retrotrans-posons.%利用 Tyl-copia类逆转座子逆转录酶( RT)的保守区域设计引物,优化了扩增条件后利用RT-PCR从白桦愈伤组织中得到了1条逆转录酶序列。利用硝普钠( SNP)和茉莉酸甲酯( MeJA)诱导后分别扩增克隆了11条和9条逆转录酶序列。这21条逆转录酶序列(命名Bprt1-21)变化范围为205~290 bp,一致性为71.93%,异质性为11.%~50.9%,翻译成氨基酸的异质性为0~57.1%。经SNP和MeJA处理的样品中,获得的逆转录酶序列基本是分别聚类,初步证明不同的Ty1-copia类逆转座子能够分别响应不同的信号而被转录激活。分析所获得的21逆转录酶序列和苹果中19条逆转录转座子序列( DQ410748~DQ410766)进化关系发现,逆转录酶

  10. Asymptomatic skin sensitization to birch predicts later development of birch pollen allergy in adults

    DEFF Research Database (Denmark)

    Bodtger, Uffe; Poulsen, Lars K.; Malling, Hans-Jørgen

    2003-01-01

    The skin prick test is the allergologic test of choice, but asymptomatic skin sensitization to aeroallergens is common. However, no data in the literature describe the clinical phenotype of asymptomatic sensitized adults....

  11. 华西雨屏区亮叶桦凋落叶分解对模拟氮沉降的响应%Response of Betula luminifera leaf litter decomposition to simulated nitrogen deposition in the Rainy Area of West China

    Institute of Scientific and Technical Information of China (English)

    涂利华; 胡红玲; 胡庭兴; 张健; 雒守华; 戴洪忠

    2012-01-01

    Aims Our objective was to determine the effect of simulated increased nitrogen (N) deposition on decomposition of Betula luminifera leaf litter, under a high wet-nitrogen deposition background.Methods From January 2008 to February 2009, a field experiment of simulated N deposition was conducted in a B. Luminifera plantation in the Rainy Area of West China. The levels of nitrogen deposition were control (CK), low, medium and high N (0, 5, 15 and 30 g Nm-2·a-1, respectively). A field experiment using the litterbag method was conducted on the decomposition of leaf litter of B. Luminifera. In the end of each month, NH4NO3 was added into N-treated plots.Important findings Despite the high background N deposition, there were significant effects of simulated increased N deposition on B. Luminifera leaf litter. N treatments significantly slowed the decomposition of B. Luminifera leaf litter through inhibiting the decay of lignin and cellulose. The time of 95% mass loss (r95%) of B. Luminifera leaf litter was increased by 1.14-1.96 a from 2.65 a (T95o/o of CK) caused by simulated N deposition. Simulated N deposition significantly increased the remaining amount of carbon, N, phosphorus, potassium, and magnesium after one year of decomposition. However, calcium release rate was stimulated by simulated N deposition in all three N treatments. The initial chemical characteristics of litter determined the response direction of litter decomposition to simulated N deposition, as well as the nutrient release pattern during litter decomposition.%从2008年1月至2009年2月,对华西雨屏区亮叶桦(Betula luminifera)人工林进行了模拟氮(N)沉降试验,N沉降水平分别为对照(CK,0gN·m-2·a-1)、低N(5 gN·m-2·a-1)、中N(15 g N·m-2·a-1)和高N(30g N·m-2·a-1).利用凋落袋法对亮叶桦凋落叶进行原位分解试验,并在每月下旬定量地对各处理施N (NH4NO3).结果表明,虽然华西雨屏区大气N沉降量较高,但模拟N沉降试验表明:在N

  12. Tree and shrub expansion over the past 34 years at the tree-line near Abisko, Sweden.

    Science.gov (United States)

    Rundqvist, Sara; Hedenås, Henrik; Sandström, Anneli; Emanuelsson, Urban; Eriksson, Håkan; Jonasson, Christer; Callaghan, Terry V

    2011-09-01

    Shrubs and trees are expected to expand in the sub-Arctic due to global warming. Our study was conducted in Abisko, sub-arctic Sweden. We recorded the change in coverage of shrub and tree species over a 32- to 34-year period, in three 50 x 50 m plots; in the alpine-tree-line ecotone. The cover of shrubs and trees (tree stems (> or =3.5 cm) were noted and positions determined. There has been a substantial increase of cover of shrubs and trees, particularly dwarf birch (Betula nana), and mountain birch (Betula pubescens ssp. czerepanovii), and an establishment of aspen (Populus tremula). The other species willows (Salix spp.), juniper (Juniperus communis), and rowan (Sorbus aucuparia) revealed inconsistent changes among the plots. Although this study was unable to identify the causes for the change in shrubs and small trees, they are consistent with anticipated changes due to climate change and reduced herbivory.

  13. 燕山北部山地人工落叶松林与天然次生林物种多样性的比较%Biodiversity between larch plantation and secondary poplar- birch forest in north region of Yanshan mountain

    Institute of Scientific and Technical Information of China (English)

    纪晓林; 贾彦龙; 卢金平; 李倩茹; 许中旗

    2011-01-01

    In order to understand the biodiversity maintain function of Larch plantation, taking 13 - year, 30 - year Larch plantation and 13 - year,28 - year secondary poplar- birch forest as research object,the biodiversity between them and the effects of thinning on Larch plantation biodiversity were investigated. Results showed that biodiversities in Larch plantation had no significant differences with secondary poplar - birch forest except Simpson Index and Shannon - weiner Index of 30 -year Larch plantation. Thinning mainly reduced the diversity of tree layer in short time, but it had no significant effect on shrub and herb layer. Larch plantation in north region of Yanshan mountain could maintain high biodiversity.%为了解燕山北部山地华北落叶松人工林植被物种多样性维持功能的高低,选取13 a和30a生人工落叶松林,以13 a和28a生天然次生杨桦林作为对照,对两种林分的植被多样性进行调查和分析,并研究了间伐对人工落叶松林植被物种多样性的影响.结果表明,林龄相同或相近的两种林分类型相比,无论是乔木层、灌木层或是草本层,人工落叶松林丰富度、Simpson指数、Shannon- Weiner指数均表现出相当或略高于天然次生杨桦林(30a生人工落叶松林乔木层多样性指数除外);间伐对人工落叶松林植被物种多样性的短期影响主要体现在乔木层,对林下灌木层和草本层无明显影响.燕山北部山地人工落叶松林具有较高的植物多样性维持功能,没有导致物种多样性的降低.

  14. Usability of multiangular imaging spectroscopy data for analysis of vegetation canopy shadow fraction in boreal forest

    Science.gov (United States)

    Markiet, Vincent; Perheentupa, Viljami; Mõttus, Matti; Hernández-Clemente, Rocío

    2016-04-01

    Imaging spectroscopy is a remote sensing technology which records continuous spectral data at a very high (better than 10 nm) resolution. Such spectral images can be used to monitor, for example, the photosynthetic activity of vegetation. Photosynthetic activity is dependent on varying light conditions and varies within the canopy. To measure this variation we need very high spatial resolution data with resolution better than the dominating canopy element size (e.g., tree crown in a forest canopy). This is useful, e.g., for detecting photosynthetic downregulation and thus plant stress. Canopy illumination conditions are often quantified using the shadow fraction: the fraction of visible foliage which is not sunlit. Shadow fraction is known to depend on view angle (e.g., hot spot images have very low shadow fraction). Hence, multiple observation angles potentially increase the range of shadow fraction in the imagery in high spatial resolution imaging spectroscopy data. To investigate the potential of multi-angle imaging spectroscopy in investigating canopy processes which vary with shadow fraction, we obtained a unique multiangular airborne imaging spectroscopy data for the Hyytiälä forest research station located in Finland (61° 50'N, 24° 17'E) in July 2015. The main tree species are Norway spruce (Picea abies L. karst), Scots pine (Pinus sylvestris L.) and birch (Betula pubescens Ehrh., Betula pendula Roth). We used an airborne hyperspectral sensor AISA Eagle II (Specim - Spectral Imaging Ltd., Finland) mounted on a tilting platform. The tilting platform allowed us to measure at nadir and approximately 35 degrees off-nadir. The hyperspectral sensor has a 37.5 degrees field of view (FOV), 0.6m pixel size, 128 spectral bands with an average spectral bandwidth of 4.6nm and is sensitive in the 400-1000 nm spectral region. The airborne data was radiometrically, atmospherically and geometrically processed using the Parge and Atcor software (Re Se applications Schl

  15. Phase 2 Site Investigations Report. Volume 1 of 3: General Annex-Wide Information

    Science.gov (United States)

    1994-09-01

    Rose Rosa mudiflora Northern Arrowwood Viburnum recognitum Northern Red Oak Quercus rubra Orchard Grass Dactylis glomerata Panic Grass Panicum sp...Paper Birch Betula papyrifera Partridge-Berry Mitchela repens Pink Ladyslipper Cypripedium Poison Ivy Toxicodendron radicans Poverty Grass Danthonia ...mixture of white pine and oak is the predominant forest type in the northern portion (Figure 2-5). Open areas vegetated with grasses , forbs, and

  16. Remedial Investigations Report for Fort Devens Subbury Training Annex, Maynard, Massachusetts, Sites P11/P13 and Sites A12/P36/P37, Phase 2. Volume 1

    Science.gov (United States)

    1995-12-01

    Poverty grass Danthonia spicata X Panic grass Panicum sp. X Common Milkweed Ascelpias syriaca X X Indian Pipe Monotropa uniflora X Pink Ladyslipper...Viburnum recognitum Northern Red Oak Quercus rubra Orchard Grass Dactylis glomerata Panic Grass Panicum sp. Paper Birch Betula papyrifera Partridge-Berry...Mitchella repens Pink Ladyslipper Cypripedium Poison Ivy Toxicodendron radicans Poverty Grass Danthonia spicata Privet Ligustrum vulgare Queen Anne’s

  17. Analysis on diameter structure of the mixed forest of Larix principis-rupprechtii Mayr.and Betula platyphylla Suk.in Mengluan Forestry Farm%河北省孟滦林场落叶松白桦混交林直径结构分析

    Institute of Scientific and Technical Information of China (English)

    崔丽红; 兰永生; 王丽华; 陈永军; 黄选瑞

    2012-01-01

    Stand diameter structure, as the most basic and important stand structure, means the distribution status of all kinds of trees with different diameters in a stand. The knowledge of the stand diameter structure is to clearly understand the results from single wood growth and stand competition. The research on the rules of dynamic changes of stand diameter structure will contribute more benefits to revealing the essence of stand development rule. The article investigates all the plants with>3 cm DBH in the mixed forest of Larix Principis-rupprechtii Mayr. and Betula platyphylla Suk. in the Mengluan Forestry Farm, Mulan Forestry Administration as research object by using sample plot method, and analyzes the distribution characteristics of diameter structure of main tree species with the statistical software Forstat2. 1. The statistic analysis shows the largest number of trees appears in the middle diameter class and the smaller number of trees in the small diameter class, with poor stand regeneration. Based on the integrated effect of normal distribution, gamma distribution, logarithmic normal distribution, binomial distribution and Poisson distribution, the forest diameter distribution law is supposed to be better reflected.%林分直径结构是林分内各种大小直径林木的分配状态,它是最基本也最重要的林分结构.了解林分的直径结构,也就对单木生长以及林分竞争所产生的结果有了清楚的认识;探讨林分直径结构动态变化规律更是有利于揭示林分发展规律的实质[1].本研究以木兰林管局孟滦林场华北落叶松白桦混交林为研究对象,采用标准地调查法对林内胸径大于3 cm的林木进行每木检尺,并使用Forstat2.1统计软件对主要树种直径结构分布规律进行研究,研究发现,各树种处于中间径阶的林木株数最多;小径阶林木较少,林分更新较差;综观拟合效果,正态分布、伽玛分布、对数正态分布、二项分布以

  18. 不同盐梯度处理下沼泽小叶桦的生理特征及叶片结构%Photosynthetic Performance and Variation in Leaf Anatomic Structure of Betula microphylla var.paludosa under Different Saline Conditions

    Institute of Scientific and Technical Information of China (English)

    王斌; 巨波; 赵慧娟; 张群; 朱义; 崔心红

    2011-01-01

    设计盐梯度(0,2‰,4‰,6‰,8‰盐溶液的质量比为NaCl∶ Na2SO4∶ NaHCO3=75%∶15%∶10%)试验分析沼泽小叶桦生理表现和叶片解剖结构.结果显示:在低于4‰盐度时沼泽小叶桦能正常生长,6%‰盐度时沼泽小叶桦生长发育不良,当盐度8‰时沼泽小叶桦只能存活30天左右;在低盐度处理下沼泽小叶桦光合生理表现和叶片解剖结构正常;随着盐度增加,其叶片净光合速率、气孔导度、胞间CO2浓度、蒸腾速率、叶绿素含量等指标均下降,而叶片中可溶性糖含量、脯氨酸含量、蛋白质含量升高;当盐度≥0.4%时,沼泽小叶桦叶片栅栏细胞逐渐纵向伸长且排列更紧密,叶绿体从椭圆形变成球形,叶绿体中出现粗大的淀粉粒和脂质球,表明其对滨海盐土具有一定的适应能力.%Betula microphylla var. Paludosa is a salt tolerant plant and naturally grows in inland. In order to explore possibility in transplanting the species to marine salina, we investigated photosynthetic performance and leaf anatomic structure of B. Microphylla , grown under control (nutrient soil) or salt-stress conditions (nutrient soil containing different salinity; 2‰, 4‰, 6‰, 8‰ of the solution for 60 days. The species had normal photosynthetic performance and leaf anatomic structure under lower salinity conditions. When soil salinity increased (≥0. 4%) , the net photosynthesis rate, stomatal conductance, transpiration rate, internal CO2 concentration, and chlorophyll content in leaves all decreased, whereas the soluble sugar, proline and protein contents of leaf increased. Accordingly, cells of the palisade tissue in B. Microphylla var. Paludosa leaf elongated and piled closely, in comparison with that under lower salinity conditions, and the chloroplasts changed from elliptical shape to round shape and in which many 1 ipid droplets and starch grains occurred in it. These results indicated that B. Microphylla var

  19. Plant Functional Types and Their Impact Environmental Factors in a Naturally Recovered Poplar-birch Woodland on the North Slope of Qilian Mountains, China%祁连山北坡自然恢复杨桦林地植物功能型组成及其影响因素

    Institute of Scientific and Technical Information of China (English)

    石福习; 赵成章; 任珩; 周伟; 高福元; 盛亚萍; 李丽丽

    2012-01-01

    Plant functional types (PFTs) are important in understanding the dynamics and the functions of an ecosystems, which provide also useful information for ecosystem management. In 28 observation plots of a naturally recovered popiar-birch woodland on the north slope of Qilian Mountains, China, 81 plant species were classified into 18 plant functional types (PFTs), according to their life forms (including arbors, lianas, subshrub, shrub, perennial grasses, perennial forbs and annual or biennial grass) and ecotypes (including xerophyte, xerophytic and mesophytic, mesophyte and hygrophyte). The relationships between PFTs and environmental factors were studied using Canonical Correspondence Analysis (CCA). The results showed that the dominant PFTs were PFTsl6 (mesophytic perennial forbs), PFTs23 (hygrophytic perennial forbs), PFTs9 (xerophytic and mesophytic perennial forbs) and PFTslS (mesophytic shrub) on the poplar-birch restoration woodland. The stratificd structure with wood, shrub and herb layers indicated the plant life forms had a tendency of complication and structurization, and the emerging mesophyte plants reflected changes of the micro-environments. The distribution patterns of PFTs were controlled by the soil physical and chemical properties in that soil bulk density, soil organic carbon and content of nitrogen determined the characteristics of the plant life forms, while the soil water moisture and canopy cover were the main ecologis factors that affected the distribution of ecotypes. The slope position and slope aspect controlled the plant distribution pattem and formation of the community.%依据生活型(乔木、藤本、灌木、半灌木、多年生禾草、多年生杂类草和一二年生草本)和水分生态型(旱生、旱中生、中生和湿生)将祁连山北坡次生杨桦林28个调查样地中的81个物种划分为18种植物功能型(Plant function types,PFTs),并通过典范对应分析(CCA)方法研究植物功能型与环境因子间

  20. Relationship between spatial isolation of trees and stand volume increment of polar-birch secondary forests in Changbai mountain%长白山杨桦次生林树种空间隔离度对林分生长的关系

    Institute of Scientific and Technical Information of China (English)

    孔雷; 亢新刚; 杨华; 谢佳利; 黄新峰; 冯启祥

    2012-01-01

    The study was based on 6 permanent plots data of polar-birch secondary forests in Changbai Mountain, which owned the same site quality, mixed proportion and diversity of trees. The plots were located and the tree diameters at breast heights were investigated. By applying hierarchical cluster method, the plots were classified according to diversity of trees and species evenness. Then the relationship between stand volume increment and spatial isolation of trees was analyzed by tree species diversity mingling method. With the same of site quality, diversity of trees, diversity of tree and mixed proportion, the results manifested that the stand volume increment in the plots declined with the incensement of spatial isolation of trees. Finally, the reasonable advices of trees spatial isolation were given, which helps to manage an optimal spatial structure.%以6块立地条件、林分密度和混交比相同的长白山天然杨桦次生林固定样地为研究对象,样地内每木检尺和定位.通过系统聚类方法划分出树种多样性和物种均匀度相同的样地,利用树种多样性混交度研究林分蓄积生长量与物种空间隔离度的关系.结果表明:在立地条件、株数密度、混交比和树种多样性相同时,样地内林分蓄积生长量与树种空间隔离度呈反比关系.最后给出树种配置方法的建议,为今后经营合理的天然次生林空间结构给予启示.

  1. 大兴安岭北部白桦次生林林内积雪及浅层土壤温度分布特征1)%Characteristics of Temperature in Snow-cover and Shallow-soil in Betula platyphylla Secondary Forests in the Northern Daxing’ an Mountains

    Institute of Scientific and Technical Information of China (English)

    朱宾宾; 满秀玲; 王树力; 俞正祥

    2015-01-01

    We studied the characteristics of temperature in snow-cover and shallow-soil by locating observation in Betula platyphylla secondary forest in the northern Daxing ’an Mountains.With the increasing of the snow depth , snow-cover had greater difference of temperature , when the snow depth was in 11.36-140.0 cm and air temperature was 13.10℃ , and the temperature diversity between snow-bottom and snow-surface was6 .89℃, however, when the depth of snow reached up to 275.-30 cm and the air temperature lowered to -30.20℃, then, the temperature diversity between snow-bottom and snow-surface got to 18.87℃.As air temperature cooled to 17.10℃, the snow-surface temperature cooled 17.31℃, snow-bottom temperature only cooled 5.34℃, which showed that certain thick snow had thermal effect on snow-bottom temperature , and the thicker the snow was , the greater insulated effect became .With the increasing of the snow depth , snow-cover had grea-ter difference of temperature-gradient, when the snow depth was 132.5 cm, the temperature-gradient diversity between the upper and lower was 0.17℃/cm, nevertheless, when the depth of snow reached up to 29.80 cm, the temperature-gradient difference soared to 0.65℃/cm, which showed that when cold air passed through the topsnow , and showed the cooling effect on subsnow .The snow-cover delayed the transmission of cold air to the subsoil , when the depth of snow was 11.36-14 cm, shallow-soil cooled 2.59℃on condition that air temperature cooled 6℃;when the depth of snow rose go up to 26.00-34.80 cm, shallow-soil merely cooled 2.63℃on condition that air temperature cooled 8℃.The thicker snow-cover was , the more obvious snow-cover sluggished the invasion of cold air to soil .Under 12.46 cm snow-cover , the temperature-gradient were 0.26℃/cm and 0.13℃/cm in soil-layers of 0-10 cm and 20-30 cm, respectively .When the snow depth was 30.22 cm, the temperature-gradients of 0-10 cm and 20-30 cm soil-layers were 0.31 and 0

  2. Leaf and twig litter decomposition of main species in different forests along the north slope of Changbai Mountain,northeast China

    Institute of Scientific and Technical Information of China (English)

    GUO Zhongling; LI Qingkang; ZHENG Jinping; LIU Wande; FAN Chunnan; MA Yuandan; YU Guirui; HAN Shijie

    2007-01-01

    From 2001 to 2003,the litter decomposition dynamics of dominant tree species were conducted using a litterbag burying method in the broadleaf-Korean pine forest,spruce-fir forest and Ermans birch forest,which represents three altitudinal belts in Changbai Mountain,northeast China.The spatial and temporal dynamics of litter decomposition and the effects of litter properties were examined.Furthermore,the decomposition trend of different species was simulated by the Olson model,and results showed that annual mass loss rates increased over time,but was not significantly correlated.Leaf decomposition rates increased after decomposing for 638 days (1.75 years),and the order of dry weight remaining rates of leaf litter for different species is:Asian white birch (Betula platyphylla) (24.56%)<Amur linden (Tilia amurensis) (24.81%) < Korean pine (Pinus koraiensis)(38.48%)<spruce (Picea jezoensis var. microsperma)(41.15%)< Ermans birch (Betula ermanii) (41.53%)<fir (Abies nephrolepis) (42.62%).The dry weight remaining rates of twig litter was smaller than that of leaf litter,and followed the order of Amur linden (44.98%)<fir (64.62%)<Korean pine (72.07%)<spruce (73.51%)<Asian white birch (77.37%)<Ermans birch (80.35%).The simulation results by the Olson model showed that,in leaf,the 95%-decomposition rates ranged from 4.5 to 8.0 years,and annual decomposition rate (k) followed the order of Amur linden (0.686)>Asian white birch (0.624)>Korean pine (0.441)>spruce (0.406)>fir (0.397)>Ermans birch (0.385);in twig,it ranged from 7.8 to 29.3 years,and k follows the order:Amur linden (0.391)>fir (0.204)>Korean pine (0.176)>spruce (0.157)>Asian white birch (0.148)>Ermans birch (0.102).In general,the differences of decomposition rate are evident between leaf and twig litter and among species,and were higher in broad-leaved species compared with coniferous species at the same elevation,and decreased with the ascending of elevation.

  3. Behaviour of a birch plywood under various experimental conditions

    Directory of Open Access Journals (Sweden)

    Caetano Lydie

    2015-01-01

    Full Text Available Liquid Natural Gaz -LNG- carriers must provide cryogenic reliability and safety for at least 40 years. Most of the insulation systems belong to the so-called membrane type, in which the “insulation complex” is composed of a metal membrane as a barrier, a plywood panel, insulation foam and a plywood panel glued to the inner hull. During construction and exploitation at cryogenic temperature, an impact of the membrane may occur and could lead to a LNG leakage. In order to evaluate this risk, and the role of the plywood in the perforation process of the membrane, a series of original impact tests are carried out at room and cryogenic temperatures on metal-plywood samples thanks to a specially designed catapult. In order to obtain a reliable numerical simulation of the impact, a series of impact and out of plane compression tests at room and cryogenic temperatures are carried out. Thanks to a design experiment, we identified the influence of the moisture content, from 2% up to 30%, and of the temperature, from − 173 ∘C up to +20 ∘C, on the strain rate sensitivity of the plywood.

  4. Thermal modification of birch using saturated and superheated steam

    OpenAIRE

    Dagbro, Ola; Torniainen, Petteri; Morén, Tom

    2011-01-01

    During the thermal modification, wood is normally exposed to temperatures between 160 - 220°C. As a result physical and chemical changes are taking place and some of the wood properties are changed. Dimensional stability and weather resistance are improved. On the other hand the mechanical strength properties are usually negatively affected by the treatment. The visual appearance is also changed. There were two different types of thermal modification processes used in this study. One of them ...

  5. Connolly Hospital (Silver Birch & Woodland Units), Blanchardstown, Dublin 15.

    LENUS (Irish Health Repository)

    Semchenko, Evgeny A

    2010-11-30

    Abstract Background Campylobacter jejuni is a major bacterial cause of food-borne enteritis, and its lipooligosaccharide (LOS) plays an initiating role in the development of the autoimmune neuropathy, Guillain-Barré syndrome, by induction of anti-neural cross-reactive antibodies through ganglioside molecular mimicry. Results Herein we describe the existence and heterogeneity of multiple LOS forms in C. jejuni strains of human and chicken origin grown at 37°C and 42°C, respectively, as determined on sodium dodecyl sulphate-polyacrylamide electrophoresis gels with carbohydrate-specific silver staining and blotting with anti-ganglioside ligands, and confirmed by nuclear magnetic resonance (NMR) spectroscopy. The C. jejuni NCTC 11168 original isolate (11168-O) was compared to its genome-sequenced variant (11168-GS), and both were found to have a lower-Mr LOS form, which was different in size and structure to the previously characterized higher-Mr form bearing GM1 mimicry. The lower-Mr form production was found to be dependent on the growth temperature as the production of this form increased from ~5%, observed at 37°C to ~35% at 42°C. The structure of the lower-Mr form contained a β-D-Gal-(1→3)-β-D-GalNAc disaccharide moiety which is consistent with the termini of the GM1, asialo-GM1, GD1, GT1 and GQ1 gangliosides, however, it did not display GM1 mimicry as assessed in blotting studies but was shown in NMR to resemble asialo-GM1. The production of multiple LOS forms and lack of GM1 mimicry was not a result of phase variation in the genes tested of NCTC 11168 and was also observed in most of the human and chicken isolates of C. jejuni tested. Conclusion The presence of differing amounts of LOS forms at 37 and 42°C, and the variety of forms observed in different strains, indicate that LOS form variation may play a role in an adaptive mechanism or a stress response of the bacterium during the colonization of different hosts.

  6. Connolly Hospital (Silver Birch & Woodland Units), Blanchardstown, Dublin 15.

    LENUS (Irish Health Repository)

    Hegerl, Ulrich

    2009-01-01

    BACKGROUND: Suicide and non-fatal suicidal behaviour are significant public health issues in Europe requiring effective preventive interventions. However, the evidence for effective preventive strategies is scarce. The protocol of a European research project to develop an optimized evidence based program for suicide prevention is presented. METHOD: The groundwork for this research has been established by a regional community based intervention for suicide prevention that focuses on improving awareness and care for depression performed within the European Alliance Against Depression (EAAD). The EAAD intervention consists of (1) training sessions and practice support for primary care physicians,(2) public relations activities and mass media campaigns, (3) training sessions for community facilitators who serve as gatekeepers for depressed and suicidal persons in the community and treatment and (4) outreach and support for high risk and self-help groups (e.g. helplines). The intervention has been shown to be effective in reducing suicidal behaviour in an earlier study, the Nuremberg Alliance Against Depression. In the context of the current research project described in this paper (OSPI-Europe) the EAAD model is enhanced by other evidence based interventions and implemented simultaneously and in standardised way in four regions in Ireland, Portugal, Hungary and Germany. The enhanced intervention will be evaluated using a prospective controlled design with the primary outcomes being composite suicidal acts (fatal and non-fatal), and with intermediate outcomes being the effect of training programs, changes in public attitudes, guideline-consistent media reporting. In addition an analysis of the economic costs and consequences will be undertaken, while a process evaluation will monitor implementation of the interventions within the different regions with varying organisational and healthcare contexts. DISCUSSION: This multi-centre research seeks to overcome major challenges of field research in suicide prevention. It pools data from four European regions, considerably increasing the study sample, which will be close to one million. In addition, the study will gather important information concerning the potential to transfer this multilevel program to other health care systems. The results of this research will provide a basis for developing an evidence-based, efficient concept for suicide prevention for EU-member states.

  7. Rhizofiltration of a Heavy Metal (Lead) Containing Wastewater Using the Wetland Plant Carex pendula

    NARCIS (Netherlands)

    Yadav, B.K.; Siebel, M.A.; Van Bruggen, J.J.A.

    2011-01-01

    Rhizofiltration is a subset technique of phytoremediation which refers to the approach of using plant biomass for removing contaminants, primarily toxic metals, from polluted water. The effective implementation of this in situ remediation technology requires experimental as well as conceptual insigh

  8. Properties of tree and grass pollen allergens: reinvestigation of the linkage between solubility and allergenicity.

    Science.gov (United States)

    Vrtala, S; Grote, M; Duchêne, M; van Ree, R; Kraft, D; Scheiner, O; Valenta, R

    1993-01-01

    In this study we reinvestigated the kinetics of allergen release from birch pollen (Betula verrucosa) and timothy grass pollen (Phleum pratense) using different protein extraction procedures, immunoblotting with specific antibodies and immune electron microscopy. Pollen allergens such as the major birch pollen allergen, Bet v I, the major timothy grass pollen allergens, Phl p I and Phl p V, group-II/III allergens from timothy grass and profilins were released rapidly and in large amounts from hydrated pollen. Within a few minutes pollen allergens could be detected in aqueous supernatants prepared from birch and grass pollen with serum IgE or specific antibodies. In parallel the allergen content in the pollen pellet fractions decreased. A nonallergenic protein such as heat shock protein 70 can be extracted in sufficient amounts only with harsh extraction procedures. Immune electron microscopy of dry and rehydrated birch pollens showed that after short hydration, the major birch pollen allergen, Bet v I, migrated into the exine and to the surface of intact pollen grains, whereas profilin, against which a lower percentage of patients is sensitized, was retained in the pollen grain. Comparing the amino acid composition and hydrophilicity of the tested allergens with a nonallergenic protein such as heat shock protein 70, no significant difference was noted. In agreement with earlier observations we conclude that the allergenic properties of proteins are rather linked to the amount and speed of solubility from airborne particles than to intrinsic properties.

  9. 温度对桦木单板表面化学镀 Ni-Cu-P三元合金的影响%Effect of Temperature on Electrlo se s Deposition of Ni-Cu-P Ternary Alloy on Birch Veneer

    Institute of Scientific and Technical Information of China (English)

    惠彬; 李坚; 王立娟

    2015-01-01

    利用化学镀方法在桦木单板表面沉积Ni—Cu—P三元合金,考查施镀温度对镀后单板表面电阻率和电磁屏蔽效能的影响,采用扫描电镜( SEM)观察镀后单板的表面形貌,利用EDS和 XPS分析镀层成分,利用X射线衍射( XRD)分析镀层的组织结构,采用直拉法测定镀层与木材表面的结合强度。结果表明:当温度从80℃升高到90℃时,镀层平均表面电阻率从0.451Ω/cm2降低至0.301Ω/cm2;继续升高温度,表面电阻率小幅升高;在90℃时,施镀单板的电磁屏蔽效能在9 kHz~1.5 GHz频段达到55~60dB 。 SEM观察发现镀层连续、致密且具有金属光泽;EDS分析可知镀层中存在Ni、Cu和P元素,XPS分析可知镀层组成为Ni、Cu、P,其质量分数分别为79.84%、11.82%和8.34%;XRD分析表明镀层为微晶态结构;镀层与木材表面结合牢固。%We used electroless plating to deposite Ni-Cu-P ternary alloy on birch veneer to study the effects of plating tempera-ture on surface resistivity and electromagnetic shielding effectiveness.We observed the surface morphology of plated veneer by scanning electron microscopy ( SEM), and analyzed the composition of the coating by energy dispersion spectrometer ( EDS) ,X -ray photoelectron spectroscopy ( XPS) and the structure of the coating by X-ray diffraction ( XRD) .We meas-ured the bonding strength between the coating and wood surface by vertical pulling method.The mean surface resistivity de-creased from 0.451Ω/cm2 to 0.301Ω/cm2 with increasing temperature from 80℃to 90℃.However, the surface resistivity increased slightly with further increasing temperature.The electromagnetic shielding effectiveness of plated veneer was up to 55-60 dB in frequencies range of 9-1.5 GHz at 90℃.By SEM, the coating was smooth, continuous and compact, and had metallic sheen.By EDS, the coating was composed of nickel, copper and phosphorus element.By XPS

  10. 大兴安岭白桦低质林皆伐改造后枯落物水文效应%Hydrological Effect of Birch Coppice Low-Quality Forest Litter after Clear-cutting Transformation in Daxing’ an Mountains

    Institute of Scientific and Technical Information of China (English)

    李超; 董希斌; 宋启亮

    2013-01-01

    对大兴安岭地区白桦低质林进行不同带宽的带状和不同面积的块状两种不同皆伐方式的改造后枯落物水文效应变化的研究。结果表明:带宽为6~18 m的皆伐带未分解层枯落物蓄积量所占比例均小于半分解层的枯落物蓄积量,面积为5 m×5 m~30 m×30 m的块状区域未分解层枯落物蓄积量所占比例和半分解层比较大小不一;枯落物蓄积量排序:带状皆伐8.67 t/hm2>块状皆伐4.41 t/hm2。每条带宽的皆伐带未分解层的最大持水量所占比例均小于半分解层的最大持水量,每个面积的块状区域未分解层的最大持水量所占比例和半分解层比较大小不一;枯落物最大持水量排序:块状皆伐35.44 t/hm2>带状皆伐14.23 t/hm2。每条皆伐带未分解层枯落物有效拦蓄量所占比例均小于半分解层的枯落物有效拦蓄量,每个面积的块状区域未分解层的有效拦蓄量所占比例和半分解层比较大小不一;枯落物有效拦蓄量排序:带状皆伐25.17 t/hm2>块状皆伐7.81 t/hm2。带状和块状皆伐方式下,枯落物持水量与浸泡时间的关系均呈现对数关系上升,而枯落物吸水速率与浸泡时间的关系均呈现乘幂关系下降。%The experiment was conducted to study the hydrological effect of falling object in Daxing’an Mountains of birch cop-pice low-quality forest in different bandwidth and different area by two different clear cuttings.The litter proportion volume in not decomposition level is less than that of the half decomposition level in bandwidth for 6 m-18 m clear cutting band. While litter proportion volume in no decomposition level has no significant relationship with the half decomposition level in the area of 5 m×5 m-30 m×30 m.The volume of litter shows band clear cutting 8.67 t/hm2>area clear cutting 4.41 t/hm2 .Water holding capacity in no decomposition layers of the largest proportion is less than that

  11. [Soil enzyme activities under two forest types as affected by different levels of nitrogen deposition].