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Sample records for betula

  1. Essential Oil of Betula pendula Roth. Buds

    Directory of Open Access Journals (Sweden)

    Betül Demirci

    2004-01-01

    Full Text Available The essential oil of Betula pendula Roth. buds was obtained using both hydrodistillation and microdistillation techniques and their chemical compositions were analyzed using both gas chromatography (GC and gas chromatography–mass spectrometry (GC-MS. Overall, more than 50 compounds were identified representing 80% and 92% for hydrodistillation and microdistillation, respectively. The main components (by hydrodistillation and microdistillation, respectively found were α-copaene (12% and 10%, germacrene D (11% and 18% and δ-cadinene (11% and 15% in the analyzed essential oils. The microdistillation technique proved to be a useful tool and compliant alternative when compared to hydrodistillation.

  2. 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.

  3. Chemical characteristics of surface colour of birch veneer (Betula pendula)

    OpenAIRE

    Yamamoto, Akio

    2015-01-01

    Julkaistu vain painettuna, saatavuus katso Bibid. Published only in printed form, availability see Bibid This thesis investigates the discoloration of veneer produced from silver birch (Betula pendula) logs by means of biochemical and chemical analyses on the veneer and sap obtained from wood which was soaked at varying temperatures (20-70 ˚C). Drastic colour development was confirmed from the sap squeezed from green birch wood. The results from biochemical tests on the sap by sodium dodec...

  4. Phytochemical Investigation, Isolation and Characterization of Betulin from Bark of Betula Utilis

    OpenAIRE

    Himanshu Joshi; Gyanendra Kumar Saxena; Vikas Singh; Ekta Arya; Rahul Pratap Singh

    2013-01-01

    Betula utilis is a hardy perennial plant of moderate size up to 20 M in height, forming the upper limit of forest vegetation. It inhabitates along the Himalayan range from Bhutan westwards, ascending to an altitude of 4200 M. The bark of Betula utilis contains sitosterol, betulin, betulic acid, oleanolic acid, acetyloleanolic acid, lupeol, lupenone, methyl betulonate, methyl betulate and a new triterpenoid karachic acid. The ethanolic extract of powdered drug of Betula utilis was prepared. Mo...

  5. Two new phenylbutanoids from inner bark of Betula pendula.

    Science.gov (United States)

    Liimatainen, Jaana; Sinkkonen, Jari; Karonen, Maarit; Pihlaja, Kalevi

    2008-02-01

    Two phenylbutanoids, 7-{3R-[(4-hydroxyphenyl)butyl] beta-glucopyranosid-O-6-yl} 4-O-beta-glucopyranosylvanillin and 3-beta-glucopyranosyloxy-1-(4-hydroxyphenyl)-butanone were isolated from an aqueous methanol extract of the inner bark of Betula pendula. Their structures were determined by NMR spectroscopy and mass spectrometry. The complete assignment of proton and carbon signals was achieved by 1D and 2D NMR experiments: selective 1D TOCSY, HSQC, HMBC and DQF-COSY. PMID:18098157

  6. Procyanidin xylosides from the bark of Betula pendula.

    Science.gov (United States)

    Liimatainen, Jaana; Karonen, Maarit; Sinkkonen, Jari

    2012-04-01

    A procyanidin dimer xyloside, catechin-(4α→8)-7-O-β-xylopyranosyl-catechin, was isolated from the inner bark of Betula pendula and its structure was determined using 1D and 2D NMR, CD and high-resolution ESIMS. Interestingly, the 7-O-β-xylopyranose unit was found to be present in the lower terminal unit of the dimer. In addition to this procyanidin dimer xyloside, an entire series of oligomeric and polymeric procyanidin xylosides was detected. Their structures were investigated by hydrophilic interaction HPLC-HRESIMS. Procyanidin glycosides are still rarely found in nature. PMID:22273040

  7. 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.

  8. FLUCTUATING ASYMMETRY OF BETULA PENDULA LEAVES AS A BIOINDICATOR OF AEROTECHNOGENIC POLLUTION OF AGROLANDSCAPES

    OpenAIRE

    Lobkov, V.; Vetrova, J.

    2014-01-01

    The main goal of our research was to determine the variability model and fluctuating asymmetry indices of the metric signs of Betula pendula as a typical species which grow uniformly in the Orel region and Orel.The following problems were solved:to collect material in the planting of silver birch in two areas;to determine the parameters of Betula pendula leaf blade and the level of its asymmetry; to explore the basic statistical properties of the asymmetry parameters of the individual feature...

  9. 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.

  10. 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..

  11. 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.

  12. The correlation of the maximum intensity of fluorescence with pigment characteristics of leaves of Betula pendula

    Science.gov (United States)

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

    2015-11-01

    Using fluorimeter Junior PAM (Heinz Walz GmbH, Germany) the fluorescence parameters of leaves of Betula pendula are investigated. A linear dependence of the maximum fluorescence (Fm) of leaves from the ratio of total chlorophylls concentration to concentration of carotenoids is obtained. Such dependence is found for samples collected during the period of vegetation and for simultaneous selection of colored leaves.

  13. Phytochemical Investigation, Isolation and Characterization of Betulin from Bark of Betula Utilis

    Directory of Open Access Journals (Sweden)

    Himanshu Joshi

    2013-05-01

    Full Text Available Betula utilis is a hardy perennial plant of moderate size up to 20 M in height, forming the upper limit of forest vegetation. It inhabitates along the Himalayan range from Bhutan westwards, ascending to an altitude of 4200 M. The bark of Betula utilis contains sitosterol, betulin, betulic acid, oleanolic acid, acetyloleanolic acid, lupeol, lupenone, methyl betulonate, methyl betulate and a new triterpenoid karachic acid. The ethanolic extract of powdered drug of Betula utilis was prepared. Most of the constituents were found to be present in the ethanolic extract. Thus it was concluded that constituents of Betula utilis bark are more soluble in polar solvents. The ethanolic extract showed the presence of alkaloids, carbohydrates, flavonoids, saponins and triterpenes. After identification of crude extract, the main work was to isolate the desired compound (betulin. So, fractionation of ethanolic extract was done by suspending it in water and then extracted it with n-hexane and dichloromethane. Betulin was isolated from dichloromethane fraction using column chromatography. Ethyl acetate and n-hexane in various ratios (1:10; 1:5; 1:3; 1:2 was used as eluent for separation of desired compound from the dichloromethane fraction. After isolation of desired compound, it was subjected to characterization. For characterization studies; melting range, TLC and spectroscopic techniques (UV, IR, Mass and NMR were utilized.

  14. CORRELATION OF CONTENT ASCORBIC ACID IN THE ASSIMILATION APPARATUS BETULA PENDULA ROTH. WITH AGENT BY PATHOLOGICAL

    OpenAIRE

    Михаил Эдуардович Баландайкин

    2014-01-01

    Features of influence of set of anthropogenic factors and phytopathologic state of tree Betula pendula on concentration of ascorbic acid in it assimilation apparatus are considered. By criterion of influence Inonotus obliquus (Pers.: Fr.) Pilat and to presence pollution adaptable ability of a plant to action stressful factors, and also possibility of development of the mechanisms which are responsible for inhibition of biosynthesis of ascorbic acid estimated. It is shown that from all analyse...

  15. Isolation, Characterization and Anticancer Potential of Cytotoxic Triterpenes from Betula utilis Bark.

    Science.gov (United States)

    Mishra, Tripti; Arya, Rakesh Kumar; Meena, Sanjeev; Joshi, Pushpa; Pal, Mahesh; Meena, Baleshwar; Upreti, D K; Rana, T S; Datta, Dipak

    2016-01-01

    Betula utilis, also known as Himalayan silver birch has been used as a traditional medicine for many health ailments like inflammatation, HIV, renal and bladder disorders as well as many cancers from ages. Here, we performed bio-guided fractionation of Betula utilis Bark (BUB), in which it was extracted in methanol and fractionated with hexane, ethyl acetate, chloroform, n-butanol and water. All six fractions were evaluated for their in-vitro anticancer activity in nine different cancer cell lines and ethyl acetate fraction was found to be one of the most potent fractions in terms of inducing cytotoxic activity against various cancer cell lines. By utilizing column chromatography, six triterpenes namely betulin, betulinic acid, lupeol, ursolic acid (UA), oleanolic acid and β-amyrin have been isolated from the ethyl acetate extract of BUB and structures of these compounds were unraveled by spectroscopic methods. β-amyrin and UA were isolated for the first time from Betula utilis. Isolated triterpenes were tested for in-vitro cytotoxic activity against six different cancer cell lines where UA was found to be selective for breast cancer cells over non-tumorigenic breast epithelial cells (MCF 10A). Tumor cell selective apoptotic action of UA was mainly attributed due to the activation of extrinsic apoptosis pathway via up regulation of DR4, DR5 and PARP cleavage in MCF-7 cells over non-tumorigenic MCF-10A cells. Moreover, UA mediated intracellular ROS generation and mitochondrial membrane potential disruption also play a key role for its anti cancer effect. UA also inhibits breast cancer migration. Altogether, we discovered novel source of UA having potent tumor cell specific cytotoxic property, indicating its therapeutic potential against breast cancer.

  16. Isolation, Characterization and Anticancer Potential of Cytotoxic Triterpenes from Betula utilis Bark.

    Directory of Open Access Journals (Sweden)

    Tripti Mishra

    Full Text Available Betula utilis, also known as Himalayan silver birch has been used as a traditional medicine for many health ailments like inflammatation, HIV, renal and bladder disorders as well as many cancers from ages. Here, we performed bio-guided fractionation of Betula utilis Bark (BUB, in which it was extracted in methanol and fractionated with hexane, ethyl acetate, chloroform, n-butanol and water. All six fractions were evaluated for their in-vitro anticancer activity in nine different cancer cell lines and ethyl acetate fraction was found to be one of the most potent fractions in terms of inducing cytotoxic activity against various cancer cell lines. By utilizing column chromatography, six triterpenes namely betulin, betulinic acid, lupeol, ursolic acid (UA, oleanolic acid and β-amyrin have been isolated from the ethyl acetate extract of BUB and structures of these compounds were unraveled by spectroscopic methods. β-amyrin and UA were isolated for the first time from Betula utilis. Isolated triterpenes were tested for in-vitro cytotoxic activity against six different cancer cell lines where UA was found to be selective for breast cancer cells over non-tumorigenic breast epithelial cells (MCF 10A. Tumor cell selective apoptotic action of UA was mainly attributed due to the activation of extrinsic apoptosis pathway via up regulation of DR4, DR5 and PARP cleavage in MCF-7 cells over non-tumorigenic MCF-10A cells. Moreover, UA mediated intracellular ROS generation and mitochondrial membrane potential disruption also play a key role for its anti cancer effect. UA also inhibits breast cancer migration. Altogether, we discovered novel source of UA having potent tumor cell specific cytotoxic property, indicating its therapeutic potential against breast cancer.

  17. Isolation, Characterization and Anticancer Potential of Cytotoxic Triterpenes from Betula utilis Bark

    Science.gov (United States)

    Joshi, Pushpa; Pal, Mahesh; Meena, Baleshwar; Upreti, D. K.; Rana, T. S.; Datta, Dipak

    2016-01-01

    Betula utilis, also known as Himalayan silver birch has been used as a traditional medicine for many health ailments like inflammatation, HIV, renal and bladder disorders as well as many cancers from ages. Here, we performed bio-guided fractionation of Betula utilis Bark (BUB), in which it was extracted in methanol and fractionated with hexane, ethyl acetate, chloroform, n-butanol and water. All six fractions were evaluated for their in-vitro anticancer activity in nine different cancer cell lines and ethyl acetate fraction was found to be one of the most potent fractions in terms of inducing cytotoxic activity against various cancer cell lines. By utilizing column chromatography, six triterpenes namely betulin, betulinic acid, lupeol, ursolic acid (UA), oleanolic acid and β-amyrin have been isolated from the ethyl acetate extract of BUB and structures of these compounds were unraveled by spectroscopic methods. β-amyrin and UA were isolated for the first time from Betula utilis. Isolated triterpenes were tested for in-vitro cytotoxic activity against six different cancer cell lines where UA was found to be selective for breast cancer cells over non-tumorigenic breast epithelial cells (MCF 10A). Tumor cell selective apoptotic action of UA was mainly attributed due to the activation of extrinsic apoptosis pathway via up regulation of DR4, DR5 and PARP cleavage in MCF-7 cells over non-tumorigenic MCF-10A cells. Moreover, UA mediated intracellular ROS generation and mitochondrial membrane potential disruption also play a key role for its anti cancer effect. UA also inhibits breast cancer migration. Altogether, we discovered novel source of UA having potent tumor cell specific cytotoxic property, indicating its therapeutic potential against breast cancer. PMID:27453990

  18. Isolation, Characterization and Anticancer Potential of Cytotoxic Triterpenes from Betula utilis Bark.

    Science.gov (United States)

    Mishra, Tripti; Arya, Rakesh Kumar; Meena, Sanjeev; Joshi, Pushpa; Pal, Mahesh; Meena, Baleshwar; Upreti, D K; Rana, T S; Datta, Dipak

    2016-01-01

    Betula utilis, also known as Himalayan silver birch has been used as a traditional medicine for many health ailments like inflammatation, HIV, renal and bladder disorders as well as many cancers from ages. Here, we performed bio-guided fractionation of Betula utilis Bark (BUB), in which it was extracted in methanol and fractionated with hexane, ethyl acetate, chloroform, n-butanol and water. All six fractions were evaluated for their in-vitro anticancer activity in nine different cancer cell lines and ethyl acetate fraction was found to be one of the most potent fractions in terms of inducing cytotoxic activity against various cancer cell lines. By utilizing column chromatography, six triterpenes namely betulin, betulinic acid, lupeol, ursolic acid (UA), oleanolic acid and β-amyrin have been isolated from the ethyl acetate extract of BUB and structures of these compounds were unraveled by spectroscopic methods. β-amyrin and UA were isolated for the first time from Betula utilis. Isolated triterpenes were tested for in-vitro cytotoxic activity against six different cancer cell lines where UA was found to be selective for breast cancer cells over non-tumorigenic breast epithelial cells (MCF 10A). Tumor cell selective apoptotic action of UA was mainly attributed due to the activation of extrinsic apoptosis pathway via up regulation of DR4, DR5 and PARP cleavage in MCF-7 cells over non-tumorigenic MCF-10A cells. Moreover, UA mediated intracellular ROS generation and mitochondrial membrane potential disruption also play a key role for its anti cancer effect. UA also inhibits breast cancer migration. Altogether, we discovered novel source of UA having potent tumor cell specific cytotoxic property, indicating its therapeutic potential against breast cancer. PMID:27453990

  19. CORRELATION OF CONTENT ASCORBIC ACID IN THE ASSIMILATION APPARATUS BETULA PENDULA ROTH. WITH AGENT BY PATHOLOGICAL

    Directory of Open Access Journals (Sweden)

    Михаил Эдуардович Баландайкин

    2014-09-01

    Full Text Available Features of influence of set of anthropogenic factors and phytopathologic state of tree Betula pendula on concentration of ascorbic acid in it assimilation apparatus are considered. By criterion of influence Inonotus obliquus (Pers.: Fr. Pilat and to presence pollution adaptable ability of a plant to action stressful factors, and also possibility of development of the mechanisms which are responsible for inhibition of biosynthesis of ascorbic acid estimated. It is shown that from all analysed in the yielded work abiotic and biotic factors most essentially the pathogenic factor affects change of concentration of ascorbic acid in sheet plates of trees concerning norm.

  20. Isolation and study of leaf proteins from trees. [Betula pendula, Polulus tremula, and Alnus incana

    Energy Technology Data Exchange (ETDEWEB)

    Bruvere, V.A.; Alksne, A.Ya.; Galvans, U.I.; Polis, O.R.

    1978-01-01

    The crude protein content of fresh leaves of (a) Betula pendula, (b) Polulus tremula and (c) Alnus incana, 10-15 years old was 18-23% of DM. Some l7 amino acids were found in analyses of purfied protein powder extracted for (a) and (b), the most abundant being glutamic acid, leucine, aspartic acid, phenylanaline and lysine. The 11 essential amino acids for pig and poultry rations constituted 60% of the total amino acids weight; the powder is equal in quality to traditional protein feeds.

  1. The variation of the onset of Betula pendula (Roth. flowering in Rzeszów, SE Poland: fluctuation or trend?

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    Idalia Kasprzyk

    2016-06-01

    Full Text Available The global rise in air temperature has major implications for ecosystems, populations, ecology of many living organisms, public health as well as economy. Plants, like silver birch (Betula pendula Roth., strongly respond to the climatic variation. Therefore, the species is a good indicator of the global climate change, especially warming. The phenological observation was undertaken to verify the hypothesis on an acceleration of the start of Betula pendula pollen release in the season. The investigations were carried out in 2000–2015 (16 years in the Rzeszów area, SE Poland. On average, Betula pendula started to pollinate in the middle of April; the difference between the earliest and latest dates was nearly 1 month. The full pollination started on 18 April, on average. The timing of pollination strongly depended on the course of weather in February and March. The most crucial was temperature in the first half of March. Considering the synergistic impact of meteorological parameters, the most important were temperature and rainfall in January and February, rainfall in March and temperature just before the pollination. It was found that North Atlantic Circulation influenced pollen release in Betula pendula. The positive North Atlantic Oscillation in March and in December–March periods resulted in pollination onset. Tendency towards warmer average annual temperature was recorded, however the timing of phenophases did not follow it. Despite the strong relationship with temperature there was no acceleration of Betula pendula pollination. Probably, the climate warming effect on the onset and duration in Betula pendula phenophases would be detectable in longer than a 16-year period.

  2. 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.

  3. 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

  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. Biomonitoring Study of Air Pollution with Betula pendula Roth., from Plovdiv, Bulgaria

    Directory of Open Access Journals (Sweden)

    Slaveya T. Petrova

    2011-07-01

    Full Text Available The present study is a small part of a program for application the methods of passive and active biomonitoring with tree, herbaceous, moss and lichen species for assessment of the anthropogenic factor in urban conditions. All reported results here are preliminary. Betula pendula was studied as a possible biomonitor of air pollution in Plovdiv. Eight sampling sites in the urban roadside, city center and suburban areas were investigated. Chlorophyll content was determined as essential and sensitive physiological parameter. The concentrations of 26 micro and macroelements were analyzed by FAAS and ICPMS. Maximum for chlorophyll was found in the birch leaves from west part of the town, minimum – in these from north part. More significant variations were detected for Ni, Mn, B, Cr, Co, Fe, Bi, Cd, Al, Zn. Highest concentrations of 12 elements were found in the samples, collected from the central area of Plovdiv.

  6. Free Recall Episodic Memory Performance Predicts Dementia Ten Years prior to Clinical Diagnosis: Findings from the Betula Longitudinal Study

    OpenAIRE

    Boraxbekk, Carl-Johan; Lundquist, Anders; Nordin, Annelie; Nyberg, Lars; Nilsson, Lars-Göran; Adolfsson, Rolf

    2015-01-01

    Background/Aims: Early dementia diagnosis is a considerable challenge. The present study examined the predictive value of cognitive performance for a future clinical diagnosis of late-onset Alzheimer's disease or vascular dementia in a random population sample. Methods: Cognitive performance was retrospectively compared between three groups of participants from the Betula longitudinal cohort. Group 1 developed dementia 11-22 years after baseline testing (n = 111) and group 2 after 1-10 years ...

  7. Biogeography of Alaska paper birch (Betula neoalaskana): latitudinal patterns in chemical defense and plant architecture.

    Science.gov (United States)

    Stevens, Michael T; Brown, Sarah C; Bothwell, Helen M; Bryant, John P

    2016-02-01

    The latitudinal herbivory-defense hypothesis (LHDH) predicts that plants near the equator will be more heavily defended against herbivores than are plants at higher latitudes. Although this idea is widely found in the literature, recent studies have called this biogeographic pattern into question. We sought to evaluate the LHDH in a high-latitude terrestrial ecosystem where fire and mammalian herbivores may contribute to selection for higher levels of defensive chemistry. To address this objective, we collected seeds of Alaska paper birch (Betula neoalaskana) from nine locations along two north-south transects between 55 degrees N and 62 degrees N latitudes in western, interior Canada. The birch seeds were planted in pots in a common garden in Madison, Wisconsin, USA. From the resulting seedlings, we determined levels of chemical defense by assessing the density of resin glands, which have been shown to be negatively correlated with browsing. To assess plant architectural traits such as height, mean individual leaf area, and root-to-shoot ratio, we harvested a subset of the birch seedlings. Further, we used these traits to examine growth-defense trade-offs. Contrary to the LHDH, we found a positive correlation between chemical defense and latitude. Investigating relationships with fire, we found a strong positive correlation between resin gland density and percentage of area annually burned (PAAB) around each collection location and also between PAAB and latitude. Additionally, birch seedlings originating from higher latitudes were shorter, smaller-leaved, and rootier than their lower-latitude counterparts. Growth-defense trade-offs were observed in negative correlations between resin gland density and height and leaf size. Seedlings with higher resin gland densities also allocated less biomass to shoots and more to roots. These results further call into question the LHDH and provide specific information about latitudinal trends in plant defense at high, northern

  8. 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.

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

    Science.gov (United States)

    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.

  10. 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.

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. 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

  14. Tolerance of an expanding subarctic shrub, Betula glandulosa, to simulated caribou browsing.

    Directory of Open Access Journals (Sweden)

    Emilie Champagne

    Full Text Available Densification of the shrub layer has been reported in many subarctic regions, raising questions about the implication for large herbivores and their resources. Shrubs can tolerate browsing and their level of tolerance could be affected by browsing and soils productivity, eventually modifying resource availability for the caribou. Our objective was to assess the compensatory growth potential of a subarctic shrub, Betula glandulosa Michx., in relation with caribou browsing and nutriment availability for the plants. We used a simulated browsing (0, 25 and 75% of available shoots and nitrogen-fertilisation (0 and 10 g m(-2 experiment to test two main hypotheses linking tolerance to resource availability, the Compensatory Continuum Hypothesis and the Growth Rate Hypothesis as well as the predictions from the Limiting Resource Model. We seek to explicitly integrate the relative browsing pressure in our predictions since the amount of tissues removed could affect the capacity of long-lived plants to compensate. Birches fully compensated for moderate browsing with an overall leaf biomass similar to unbrowsed birches but undercompensated under heavy browsing pressure. The main mechanism explaining compensation appears to be the conversion of short shoots into long shoots. The leaf area increased under heavy browsing pressure but only led to undercompensation. Fertilisation for two consecutive years did not influence the response of birch, thus we conclude that our results support the LRM hypothesis of equal tolerance under both high and low nitrogen availability. Our results highlight that the potential for compensatory growth in dwarf birch is surpassed under heavy browsing pressure independently of the fertilisation regime. In the context of the worldwide decline in caribou herds, the reduction in browsing pressure could act synergistically with global climate change to promote the current shrub expansion reported in subarctic 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. 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.

  17. 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.

  18. 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.

  19. Dormancy release and chilling requirement of buds of latitudinal ecotypes of Betula pendula and B. pubescens.

    Science.gov (United States)

    Myking, T; Heide, O M

    1995-11-01

    Bud burst and dormancy release of latitudinal ecotypes of Betula pendula Roth and B. pubescens Ehrh. from Denmark ( approximately 56 degrees N), mid-Norway ( approximately 64 degrees N) and northern Norway ( approximately 69 degrees N) were studied in controlled environments. Dormant seedlings were chilled at 0, 5 or 10 degrees C from October 4 onward and then, at monthly intervals from mid-November to February, batches of seedlings were held at 15 degrees C in an 8-h (SD) or 24-h (LD) photoperiod to permit flushing. A decline in days to bud burst occurred with increasing chilling time in all ecotypes. In November, after 44 chilling days, time to bud burst was least in plants chilled at 0 and 5 degrees C. The difference diminished with increasing chilling time, and in February, after 136 chilling days, bud burst was earliest in plants chilled at 10 degrees C. Long photoperiods during flushing significantly reduced thermal time after short chilling periods (44 and 74 days), but had no effect when the chilling requirement was fully met after 105 or more chilling days. No significant difference in these responses was found between the two species. In both species, chilling requirement decreased significantly with increasing latitude of origin. Bud burst was normal in seedlings overwintered at 12 degrees C, but was erratic and delayed in seedlings overwintered at 15 and especially at 21 degrees C, indicating that the critical overwintering temperature is between 12 and 15 degrees C. We conclude that there is little risk of a chilling deficit in birch under Scandinavian winter conditions even with a climatic warming of 7-8 degrees C. The likely effects of a climatic warming include earlier bud burst, a longer growing season and increased risk of spring frost injury, especially in high latitude ecotypes. PMID:14965987

  20. Individual tree mortality of silver birch (Betula pendula Roth in Estonia

    Directory of Open Access Journals (Sweden)

    Maleki K

    2016-08-01

    Full Text Available The functioning of complex forest ecosystems is intimately related to their structural properties. Tree mortality is a major driver of forest stand dynamics and therefore plays an important role in the formation of forest structure. Data from the Estonian Network of Forest Research Plots (ENFRP was used to estimate the mortality probability of silver birch trees (Betula pendula Roth by using logistic models. In this study several spatial and non-spatial variables were tested to determine the most important mortality explanatory factors. Additionally, thinning variables were defined and implemented into the mortality models, to examine whether thinning practices could modify the stand structure and density, then leading to a lower mortality rate. The results of this study showed that tree mortality models that included either a five-year diameter growth rate (id5 as a measure of tree vitality, or the tree relative diameter (drel as a measure of competition, or both these two variables, were substantially better than any models not including these variables. In addition, any measures of spatial aggregation (agg and species proportion (sp within the zone of influence markedly improved the model predictions, though the mortality probability of trees declined where there was higher aggregation and species mixture. Our results also suggested that if thinning were conducted around the birch trees, depending on the thinning intensity, the number of neighbors is effectively reduced, and consequently the competition load within the influence zone decreases, leading to healthier growth and lower mortality rates of the shade-intolerant birch trees. We thus recommend to adopt thinning regimes in mixed forest stands to foster tree species diversity, and at the same time provide adequate growing space for birch trees within the stands. This will improve the forest structure and increase the adaptive capacity of forests, which is increasingly important under

  1. 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.

  2. 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.

  3. 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

    -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 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...

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

    Directory of Open Access Journals (Sweden)

    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

  5. [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. PMID:19795631

  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. Phenolic compounds of the inner bark of Betula pendula: seasonal and genetic variation and induction by wounding.

    Science.gov (United States)

    Liimatainen, Jaana; Karonen, Maarit; Sinkkonen, Jari; Helander, Marjo; Salminen, Juha-Pekka

    2012-11-01

    The contents of individual phenolic compounds in the inner bark of silver birch (Betula pendula Roth) were analyzed by HPLC-DAD. Samples from 21 mature trees originating from three micropropagated parent trees were collected six times over a 1-year period. Significant seasonal variation in the quantities of ten compounds and four chromatographically unresolved compound pairs was found. A majority of the compounds also exhibited significant quantitative variation among birch clones. There were no qualitative differences associated with the season or among the clones. However, wounding of the bark induced the production of new types of bark phenolics: several ellagitannins were detected in the callus tissues of birch for the first time. PMID:23065107

  8. 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.

  9. 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...

  10. Characterization of PR-10 genes from eight Betula species and detection of Bet v 1 isoforms in birch pollen

    Directory of Open Access Journals (Sweden)

    van't Westende Wendy PC

    2009-03-01

    Full Text Available Abstract Background Bet v 1 is an important cause of hay fever in northern Europe. Bet v 1 isoforms from the European white birch (Betula pendula have been investigated extensively, but the allergenic potency of other birch species is unknown. The presence of Bet v 1 and closely related PR-10 genes in the genome was established by amplification and sequencing of alleles from eight birch species that represent the four subgenera within the genus Betula. Q-TOF LC-MSE was applied to identify which PR-10/Bet v 1 genes are actually expressed in pollen and to determine the relative abundances of individual isoforms in the pollen proteome. Results All examined birch species contained several PR-10 genes. In total, 134 unique sequences were recovered. Sequences were attributed to different genes or pseudogenes that were, in turn, ordered into seven subfamilies. Five subfamilies were common to all birch species. Genes of two subfamilies were expressed in pollen, while each birch species expressed a mixture of isoforms with at least four different isoforms. Isoforms that were similar to isoforms with a high IgE-reactivity (Bet v 1a = PR-10.01A01 were abundant in all species except B. lenta, while the hypoallergenic isoform Bet v 1d (= PR-10.01B01 was only found in B. pendula and its closest relatives. Conclusion Q-TOF LC-MSE allows efficient screening of Bet v 1 isoforms by determining the presence and relative abundance of these isoforms in pollen. B. pendula contains a Bet v 1-mixture in which isoforms with a high and low IgE-reactivity are both abundant. With the possible exception of B. lenta, isoforms identical or very similar to those with a high IgE-reactivity were found in the pollen proteome of all examined birch species. Consequently, these species are also predicted to be allergenic with regard to Bet v 1 related allergies.

  11. What was behind the bark? : An assessment of decay among urban Tilia, Betula and Acer trees felled as hazardous in the Helsinki City area

    OpenAIRE

    Terho, Minna

    2009-01-01

    Old trees growing in urban environments are often felled due to symptoms of mechanical defects that could be hazardous to people and property. The decisions concerning these removals are justified by risk assessments carried out by tree care professionals. The major motivation for this study was to determine the most common profiles of potential hazard characteristics for the three most common urban tree genera in Helsinki City: Tilia, Betula and Acer, and in this way improve management pract...

  12. 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.

  13. Influence of different particle sizes in the bark chemical composition of Eucalyptus globulus Labill., Betula pendula Roth, Picea abies (L.) Karst, Pinus sylvestris L. e Pinus pinea L.

    OpenAIRE

    Mirra, Inês Martins Pereira

    2011-01-01

    Mestrado em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia The goal of this report is to characterize the bark of five industrially important forest species in Europe - Eucalyptus globulus, Betula pendula, Picea abies, Pinus sylvestris e Pinus pinea and to define their potential use as a source of value added chemical products. It was performed the anatomical characterization of bark tissues (dissociated elements), the selective fractionation (si...

  14. Ectomycorrhizal Community Structure of Salix and Betula spp. at a Saline Site in Central Poland in Relation to the Seasons and Soil Parameters

    OpenAIRE

    Hrynkiewicz, Katarzyna; Szymańska, Sonia; Piernik, Agnieszka; Thiem, Dominika

    2015-01-01

    Saline stress is one of the most important abiotic factors limiting the growth and development of plants and associated microorganisms. While the impact of salinity on associations of arbuscular fungi is relatively well understood, knowledge of the ectomycorrhizal (EM) fungi of trees growing on saline land is limited. The main objective of this study was to determine the density and diversity of EM fungi associated with three tree species, Salix alba, Salix caprea and Betula pendula, growing ...

  15. Genetic diversity of Betula luminifera populations at different elevations in Wuyi Mountain and its association with ecological factors

    Institute of Scientific and Technical Information of China (English)

    Yiqing XIE; Zhizhen LI; Ruzhu HUANG; Xiangxi XIAO; Yong HUANG

    2009-01-01

    The random amplified polymorphic DNA (RAPD) technique was used to evaluate the genetic diversity and population structure of 91 genets from four wild populations of Betula luminifera at different eleva-tions in the National Nature Reserve of the Wuyi Mountain,Fujian Province, China. Eighteen random primers (from 139 primers) produced a total of 199 scorable amplified fragments, of which 174 (87.44%) were polymorphic across all individuals. The genetic diversities of B.luminifera at the population level and species level were PPL = 60.05%, h = 0.2242, I= 0.3181 and PPL = 87.44%,h = 0.3442, I= 0.4899, respectively. The value of differ-entiation (Gst= 0.3486) and analysis of molecular variance (AMOVA) indicated that there was a relatively high genetic differentiation among populations, and about one-third of the genetic variation occurred among populations. Pearson correlation analysis further revealed that the genetic diversity within populations had significant or very significant correlation with the elevation, climatic factors (annual average temperature and annual precipitation) and soil nutrient factors (total nitrogen, C/N ratio and organic matter). Mantel tests show that there was a significant correlation between the genetic distances among popula-tions and the distance of elevation, and the divergence of soil nutrient factors. The results of the present study suggested that the relatively high genetic differentiation among populations ofB. luminifera at different elevations might be caused by ecological factors and gene flow.

  16. Vertical profiles reveal impact of ozone and temperature on carbon assimilation of Betula pendula and Populus tremula.

    Science.gov (United States)

    Mäenpää, Maarit; Riikonen, Johanna; Kontunen-Soppela, Sari; Rousi, Matti; Oksanen, Elina

    2011-08-01

    Rising temperature and tropospheric ozone (O(3)) concentrations are likely to affect carbon assimilation processes and thus the carbon sink strength of trees. In this study, we investigated the joint action of elevated ozone and temperature on silver birch (Betula pendula) and European aspen (Populus tremula) saplings in field conditions by combining free-air ozone exposure (1.2 × ambient) and infrared heaters (ambient +1.2 °C). At leaf level measurements, elevated ozone decreased leaf net photosynthesis (P(n)), while the response to elevated temperature was dependent on leaf position within the foliage. This indicates that leaf position has to be taken into account when leaf level data are collected and applied. The ozone effect on P(n) was partly compensated for at elevated temperature, showing an interactive effect of the treatments. In addition, the ratio of photosynthesis to stomatal conductance (P(n)/g(s) ratio) was decreased by ozone, which suggests decreasing water use efficiency. At the plant level, the increasing leaf area at elevated temperature resulted in a considerable increase in photosynthesis and growth in both species.

  17. 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.

  18. 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.

  19. 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

  20. The effects of Betula platyphylla bark on amyloid beta-induced learning and memory impairment in mice.

    Science.gov (United States)

    Cho, Namki; Lee, Hee Kyoung; Jeon, Byung Ju; Kim, Hyeon Woo; Kim, Hong Pyo; Lee, Jong-Hwan; Kim, Young Choong; Sung, Sang Hyun

    2014-12-01

    Alzheimer's disease (AD) is closely associated with amyloid β (Aβ)-induced neurotoxicity and oxidative stress in the brain. Betula platyphylla, which has been used to treat various oxidative-stressed related diseases, has recently received attention for its preventive activity on age-related neurodegenerative diseases. In this study, we attempted to investigate the effects of B. platyphylla bark (BPB-316) on Aβ(1-42)-induced neurotoxicity and memory impairment. Oral treatment using BPB-316 significantly attenuated Aβ-induced memory impairment which was evaluated by behavioral tests including the passive avoidance, Y-maze and Morris water maze test. BPB-316 also inhibited the elevation of β-secretase activity accompanying the reduced Aβ(1-42) levels in the hippocampus of the brain. Furthermore, BPB-316 significantly decreased the acetylcholinesterase activity and increased the glutathione content in the hippocampus. In addition, we confirmed that the expression of both cAMP responsive element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in the hippocampus of Aβ(1-42)-injected mice were markedly upregulated by the treatment of BPB-316. Our data suggest that the extracts of B. platyphylla bark might be a potential therapeutic agent against AD.

  1. 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.

  2. 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. 

  3. 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.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Daily dynamics of leaf and soil-to-branch hydraulic conductance in silver birch (Betula pendula) measured in situ.

    Science.gov (United States)

    Õunapuu, Eele; Sellin, Arne

    2013-07-01

    Daily dynamics of leaf (K(L)) and soil-to-branch hydraulic conductance (KS-B) was investigated in silver birch (Betula pendula Roth.) using evaporative flux method in situ: water potential drop was measured with a pressure chamber and evaporative flux was estimated as sap flux density measured with sap flow gauges. Canopy position had a significant (P effect on both K(L) and K(S-B). Upper-canopy leaves exhibited 1.7 and soil-to-branch pathway 2.3 times higher hydraulic efficiency than those for lower-canopy. K(L) varied significantly with time of day: K(L) for both upper- and lower-canopy leaves was lowest in the morning and rose gradually achieving maximal values in late afternoon (4.75 and 3.38 mmol m⁻² s⁻¹ MPa⁻¹, respectively). Relevant environmental factors affecting K(L) were photosynthetic photon flux density (Q(P)), air relative humidity (RH) and air temperature (T(A)). K(S-B) started rising in the morning and reached maximum in the lower canopy (1.44 mmol m⁻² s⁻¹ MPa⁻¹) at 1300 h and in the upper canopy (2.52 mmol m⁻² s⁻¹ MPa⁻¹) at 1500 h, decreasing afterwards. Environmental factors controlling K(S-B) were Ψ(S) and Q(P). The diurnal patterns of K(L) reflect a combination of environmental factors and endogenous rhythms. The temporal pattern of K(S-B) refers to daily up- and down-regulation of hydraulic conductance of water transport pathway from soil-root interface to leaves with respect to changing irradiance.

  7. Impact of light quality on leaf and shoot hydraulic properties: a case study in silver birch (Betula pendula).

    Science.gov (United States)

    Sellin, Arne; Sack, Lawren; Õunapuu, Eele; Karusion, Annika

    2011-07-01

    Responses of leaf and shoot hydraulic conductance to light quality were examined on shoots of silver birch (Betula pendula), cut from lower ('shade position') and upper thirds of the crowns ('sun position') of trees growing in a natural temperate forest stand. Hydraulic conductances of leaf blades (K(lb) ), petioles (K(P) ) and branches (i.e. leafless stem; K(B) ) were determined using a high pressure flow meter in steady state mode. The shoots were exposed to photosynthetic photon flux density of 200-250 µmol m⁻² s⁻¹ using white, blue or red light. K(lb) depended significantly on both light quality and canopy position (Peffect on K(P) . The highest values of K(lb) were recorded under the blue light (3.63 and 3.13×10⁻⁴ kg m⁻² MPa⁻¹ s⁻¹ for the sun and shade leaves, respectively), intermediate values under white light (3.37 and 2.46×10⁻⁴ kg m⁻² MPa⁻¹ s⁻¹ , respectively) and lowest values under red light (2.83 and 2.02×10⁻⁴ kg m⁻² MPa⁻¹ s⁻¹, respectively). Light quality has an important impact on leaf hydraulic properties, independently of light intensity or of total light energy, and the specific light receptors involved in this response require identification. Given that natural canopy shade depletes blue and red light, K(lb) may be decreased both by reduced fluence and shifts in light spectra, indicating the need for studies of the natural heterogeneity of K(lb) within and under canopies, and its impacts on gas exchange.

  8. 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. PMID:26342266

  9. 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.

  10. 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.

  11. 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.

  12. Foliar responses of understorey Abies lasiocarpa to different degrees of release cutting of Betula papyrifera and conifer mixed species stand

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.R.; Letchford, T. [Ministry of Forests, Prince George, BC (Canada). Red Rock Research Station; Comeau, P.G. [BC Ministry of Forests, Victoria, BC (Canada); Coopersmith, D. [BC Ministry of Forests, Prince George, BC (Canada)

    2000-07-01

    Foliar responses of subalpine fir (Abies lasiocarpa (Hook.) Nutt.) to thinning were studied in a 35-yr-old mixed stand of paper birch (Betula papyrifera Marsh.) and conifers. The stand regenerated naturally after a wildfire with a canopy dominated by paper birch (average height 9.8 m) and an understorey dominated by subalpine fir (average height 1.6 m). The stand was thinned to four densities of birch: 0, 600 and 1200 stems ha{sup -1} and control (Unthinned at 2300-6400 stems ha{sup -1}) in the autumn of 1995. The understorey conifers, mainly subalpine fir, were thinned to 1200 stems ha{sup -1}. The study used a completely randomized split-plot design. Three sample trees were systematically selected from each treatment replicate and each tree stratum (upper, intermediate and lower understorey). One-year-old and older age class needles were collected from one south-facing branch within the fifth whorl from the tree top. Thinning of paper birch significantly (p<0.001) increased leaf area and dry weight per 100 needles for intermediate and short trees except in the 0 birch treatment. Understorey subalpine fir trees in 600 stems ha{sup -1} birch (T3) had the largest leaf area and leaf dry weight per 100 1-yr-old needles. Specific leaf area (SLA) decreased from unthinned (T1) to 0 birch (T4). Lower understorey trees had the largest SLA. One-year-old needles had significantly higher N, P and K concentrations in all the thinning treatments. These responses are consistent with the shade tolerance of subalpine fir. The results suggest that when managing a paper birch-conifers mixed wood forest it may be of benefit to understorey conifers to leave a birch canopy as a nursing crop.

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

    OpenAIRE

    Frankowski, Marcin

    2015-01-01

    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 co...

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

    Directory of Open Access Journals (Sweden)

    Lucyna Pawłowska

    2014-02-01

    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.

  15. Light Media Selection for Growing Micro-propagated Seedlings of Betula alnoides%西南桦组培苗培育的轻基质筛选

    Institute of Scientific and Technical Information of China (English)

    贾宏炎; 曾杰; 黎明; 蒙彩兰; 郭文福

    2012-01-01

    Light media selection trial was conducted for cultivating micro-propagated seedlings of Betula alnoides. It was indicated that the media, clones and their interactions had significant (P 0. 05 ). The three light media were remarkably better than soil for the growth of B. alnoides seedlings. The flexibilities of five clones to these light media were also quite different, for example, the clone B5 adapted to all the media. As a whole, the medium with 25 percent of pine skin and 75 percent of carbonized sawdust was the best for cultivating micro-propagated seedlings of B. alnoides, and was recommended to be used in practice.

  16. Woody Biomass and Carbon Stocks of Natural vs. Restored Mountain Birch (Betula pubescens, Ehrh.) Woodlands in South Iceland

    Science.gov (United States)

    Hunziker, Matthias; Sigurdsson, Bjarni D.; Halldorsson, Gudmundur; Kuhn, Nikolaus J.

    2010-05-01

    Following a period of land degradation lasting more than one thousand years, Iceland has been undertaken ambitious restoration and afforestation efforts for one century now. Afforestation has also been a central venture of the Icelandic government in order to meet the commitments assigned by the Kyoto Protocol because vegetation represents an important carbon sink. Yet, currently little is known on how much carbon is sequestrated effectively in afforested Icelandic woody ecosystems. In order to fill this knowledge gap the 'KolBjörk' (CarbBirch), a three year (2008-2011) Icelandic ecosystem research project, was launched. In this project the development of key ecosystem factors are studied in a chronosequence study of restored birch woodlands, ranging from 0-60 years in age. These factors are: a) forest growth, b) plant communities, c) soil biota, d) soil chemistry and physics and e) carbon stocks and fluxes. Restored woodlands are compared with: a) eroded land, representing the status of the area before restoration and b) original birch woodlands. The aim of present study which is part of 'KolBjörk' was to estimate the above-and belowground woody biomass and carbon stocks of old native birch (Betula pubescens) vs. restored birch woodlands in South Iceland. In summer 2009 31 trees (0.1-5.5m height) were measured and excavated and tree inventories (n=519) were established. The excavated trees formed the dataset to establish allometric biomass functions for young, afforested Icelandic mountain birch. The functions were statistically fitted using numerical nonlinear regression using Matlab. Subsequently, forest biomass and carbon stock of the four different old sites were estimated by the newly developed allometric relationships. The age of the four sites is 10, 15, 60 and 80 years, respectively, while the 80-yr old stand represents a natural grown forest, the others are replanted. The total C-stock in the 10-yr old birch stand was 2.0 Mg/ha, in the 15-yr old 11.0 Mg

  17. Responses in the start of Betula (birch) pollen seasons to recent changes in spring temperatures across Europe

    Science.gov (United States)

    Emberlin, J.; Detandt, M.; Gehrig, R.; Jaeger, S.; Nolard, N.; Rantio-Lehtimäki, A.

    2002-07-01

    A shift in the timing of birch pollen seasons is important because it is well known to be a significant aeroallergen, especially in NW Europe where it is a notable cause of hay fever and pollen-related asthma. The research reported in this paper aims to investigate temporal patterns in the start dates of Betula (birch) pollen seasons at selected sites across Europe. In particular it investigates relationships between the changes in start dates and changes in spring temperatures over approximately the last 20 years. Daily birch pollen counts were used from Kevo, Turku, London, Brussels, Zurich and Vienna, for the core period from 1982 to 1999 and, in some cases, from 1970 to 2000. The sites represent a range of biogeographical situations from just within the Arctic Circle through to North West Maritime and Continental Europe. Pollen samples were taken with Hirst-type volumetric spore traps. Weather data were obtained from the sites nearest to the pollen traps. The timing of birch pollen seasons is known to depend mostly on a non-linear balance between the winter chilling required to break dormancy, and spring temperatures. Pollen start dates and monthly mean temperatures for January through to May were compiled to 5-year running means to examine trends. The start dates for the next 10 years were calculated from regression equations for each site, on the speculative basis that the current trends would continue. The analyses show regional contrasts. Kevo shows a marked trend towards cooler springs and later starts. If this continues the mean start date will become about 6 days later over the next 10 years. Turku exhibits cyclic patterns in start dates. A current trend towards earlier starts is expected to continue until 2007, followed by another fluctuation. London, Brussels, Zurich and Vienna show very similar patterns in the trends towards earlier start dates. If the trend continues the mean start dates at these sites will advance by about 6 days over the next 10

  18. 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

  19. 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)

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

    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

  20. 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

  1. 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

  2. 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

  3. Effect of aluminium on in vitro rooting of birch (Betula pendula Roth. and poplar (Populus tremula L. x P. alba L. microcuttings

    Directory of Open Access Journals (Sweden)

    Krystyna Bojarczuk

    2014-02-01

    Full Text Available Poplar (Populus tremula L. x P. alba L. and birch (Betula pendula Roth. microcuttings obtained from in vitro cultures on media with aluminium (Al+ or without aluminium (Al- were rooted in perlite saturated with a liquid 1/4 MS medium. Aluminium was added to the rooting medium in the form of aluminium sulphate or aluminium chloride. In the control, i.e. in the medium without aluminium, Al+ and Al- shoots usually developed similarly. Addition of aluminium to the rooting medium had a negative effect on the development of adventitious roots. Poplar and birch shoots obtained from cultures on media with aluminium (AI+ were distinguished by a greater tolerance of aluminium in the medium than shoots obtained from cultures on media without aluminium (A1-.

  4. 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.

    Science.gov (United States)

    Tervahauta, Arja I; Fortelius, Carola; Tuomainen, Marjo; Akerman, Marja-Leena; Rantalainen, Kimmo; Sipilä, Timo; Lehesranta, Satu J; Koistinen, Kaisa M; Kärenlampi, Sirpa; Yrjälä, Kim

    2009-01-01

    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 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.

  5. Validation of Two Names Betula jiulungensis (Betulaceae) and Rubia ovatifolia (Rubiaceae)%九龙桦(桦木科)与卵叶茜草(茜草科)名称的合格发表

    Institute of Scientific and Technical Information of China (English)

    林祁

    2007-01-01

    由于同时指定两号标本为模式,桦木科(Betulaceae)的九龙桦(Betula jiulungensis Hu exP.C.Li)和茜草科(Rubiaceae)的卵叶茜草(Rubia ovatifolia Z.Y.Zhang)是不合格发表的名称.现通过分别指定主模式,对九龙桦和卵叶茜草的名称作合格发表.

  6. [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

  7. The Evaluation of CP-001 (a Standardized Herbal Mixture of Houttuynia cordata, Rehmannia glutinosa, Betula platyphylla, and Rubus coreanus for Cytochrome P450-Related Herb-Drug Interactions

    Directory of Open Access Journals (Sweden)

    Hye Hyun Yoo

    2013-01-01

    Full Text Available In the present study, the effect of CP-001, a standardized herbal mixture of Houttuynia cordata, Rehmannia glutinosa, Betula platyphylla, and Rubus coreanus, on cytochrome P450 (CYP enzyme-mediated drug metabolism was investigated in vitro to evaluate the potential for herb-drug interactions. CP-001 was tested at concentrations of 1, 3, 10, 30, and 100 μg/mL. A CYP-specific substrate mixture was incubated with CP-001 in human liver microsomes, and the metabolites generated by each CYP-specific metabolic reaction were measured by liquid chromatography-tandem mass spectrometry. CP-001 seemed to slightly inhibit some CYP isozymes, but the IC50 values for all CYP isozymes were greater than 100 μg/mL. Furthermore, CP-001 did not exhibit time-dependent CYP inhibitory activities, indicating that it does not act as a mechanism-based inactivator of CYP enzymes. In conclusion, the effects of CP-001 on CYP isozyme activities were negligible at the concentrations tested. Therefore, the likelihood of herbal mixture-drug interaction is considered minimal.

  8. Dependence of Guaiacol Peroxidase Activity and Lipid Peroxidation Rate in Drooping Birch (Betula pendula Roth and Tillet (Tilia cordata Mill Leaf on Motor Traffic Pollution Intensity

    Directory of Open Access Journals (Sweden)

    Elena A. Erofeeva

    2015-06-01

    Full Text Available Hormesis and paradoxical effects are frequently found for different plant parameters. These phenomena were also observed for lipid peroxidation (LP rate at environmental pollution. However, the role of antioxidant enzymes, particularly guaiacol peroxidases (GPX, in a nonmonotonic variation in the LP rate remains insufficiently explored. Therefore, dependence of GPX activity and LP rate in Betula pendula and Tilia cordata leaf on motor traffic pollution intensity was studied. Regression analysis revealed dependences of LP rate and GPX activity on traffic intensity. In B pendula, GPX activity enhanced significantly (up to 2.8 times relatively control under increased traffic that induced biphasic paradoxical effect for LP rate. In the first phase, LP level increased in comparison with the control, and in the second phase, it was normalized by enhanced GPX activity. In T cordata, dependences of GPX activity and LP rate on traffic pollution were paradoxical effects. However, there was no connection between change of GPX activity and LP rate under middle- and high-level pollution: LP level reduced relatively the control or normalized even if GPX activity was lower than the control. This indicates that in T cordata, other regulatory mechanisms instead of GPX were activated which could control LP rate under middle- and high-level pollution.

  9. The influence of weather conditions on the course of pollen seasons of alder (Alnus spp., hazel (Corylus spp. and birch (Betula spp. in Lublin (2001-2006

    Directory of Open Access Journals (Sweden)

    Agnieszka Dąbrowska

    2012-12-01

    Full Text Available The start and rate of florescence of Alnus, Corylus and Betula are dependent on meteorological conditions. In the present paper we have analysed the effect of mean, maximum and minimum temperature, relative air humidity and precipitation on the onset of the pollen season as well as on its length and annual count of pollen grains in alder, hazel and birch. The measurement of pollen fall was done by the gravimetric methods with the use of Durham sampler. Correlation coefficients were calculated between the determined characteristics of the pollen season and weather conditions. In the six-year research period 2001-2006 it was observed that low temperatures in January produced a delayed start of the pollen season in alder, hazel and birch. The beginning of flowering in these taxa was also influenced by thermal conditions prevailing directly before the season (ca. 10 days. The pollen season of the trees in question tended to be prolonged alongside with the increase in relative air humidity, but it was shortened due to higher temperatures. The volume of alder and hazel pollen release increased together with the rise in relative air humidity and precipitation. The annual counts of birch pollen increased along with rising temperature and decreasing relative air humidity and precipitation in the season.

  10. 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.

  11. 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. PMID:26370811

  12. 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.

  13. 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.

  14. 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}.

  15. 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.

  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. Combination treatment of elevated UVB radiation, CO2 and temperature has little effect on silver birch (Betula pendula) growth and phytochemistry.

    Science.gov (United States)

    Lavola, Anu; Nybakken, Line; Rousi, Matti; Pusenius, Jyrki; Petrelius, Mari; Kellomäki, Seppo; Julkunen-Tiitto, Riitta

    2013-12-01

    Elevations of carbon dioxide, temperature and ultraviolet-B (UBV) radiation in the growth environment may have a high impact on the accumulation of carbon in plants, and the different factors may work in opposite directions or induce additive effects. To detect the changes in the growth and phytochemistry of silver birch (Betula pendula) seedlings, six genotypes were exposed to combinations of ambient or elevated levels of CO2 , temperature and UVB radiation in top-closed chambers for 7 weeks. The genotypes were relatively similar in their responses, and no significant interactive effects of three-level climate factors on the measured parameters were observed. Elevated UVB had no effect on growth, nor did it alter plant responses to CO2 and/or temperature in combined treatments. Growth in all plant parts increased under elevated CO2 , and height and stem biomass increased under elevated temperature. Increased carbon distribution to biomass did not reduce its allocation to phytochemicals: condensed tannins, most flavonols and phenolic acids accumulated under elevated CO2 and elevated UVB, but this effect disappeared under elevated temperature. Leaf nitrogen content decreased under elevated CO2 . We conclude that, as a result of high genetic variability in phytochemicals, B. pendula seedlings have potential to adapt to the tested environmental changes. The induction in protective flavonoids under UVB radiation together with the positive impact of elevated CO2 and temperature mitigates possible UVB stress effects, and thus atmospheric CO2 concentration and temperature are the climate change factors that will dictate the establishment and success of birch at higher altitudes in the future.

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

    Directory of Open Access Journals (Sweden)

    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.

  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. [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.

  1. 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

  2. [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.

  3. 天然杨-桦次生林空间结构特征%Spatial structural characteristics of natural Populus davidiana - Betula platyphylla secondary forest

    Institute of Scientific and Technical Information of China (English)

    邵芳丽; 余新晓; 宋思铭; 赵阳

    2011-01-01

    运用直径分布和空间结构参数混交度、大小比数和角尺度,分析了木兰围场4 hm2天然杨-桦次生林的空间结构.结果表明:天然杨-桦次生林林分径级结构呈反“J”型曲线;林分平均混交度为0.4,其弱度和零度混交比例达51.6%,山杨、白桦的平均混交度分别为0.25和0.39;以胸径、树高为参数的大小比数基本一致,显示山杨、白桦处于亚优势向中庸的过渡状态;林分水平分布格局与树木起测直径密切相关,当起测直径为1 cm≤DBH<6 cm时,林分呈聚集分布,当起测直径DBH≥6 cm时,林分呈随机分布.%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 ≥1 cm and <6 cm, and random when the DBH was ≥6 cm.

  4. 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

  5. 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.

  6. 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 .

  7. 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

  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. 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.

  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. 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.

  12. 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. PMID:26595095

  13. Preliminary Study of Predominant Factors on Chromosome Doubling ofBetula alnoides%西南桦染色体加倍的影响因子初步研究

    Institute of Scientific and Technical Information of China (English)

    陈荣; 朱昌叁; 庞正轰

    2014-01-01

    In this paper, a method for chromosome doubling ofBetula alnoideswas developed. Terminal buds from aseptic germination ofB. alnoides were used as explants, effect factors on chromosome doubling ofB. alnoides were discussed, such as concentration of colchicine, co-culture time of colchicine, preculture time. The results showed that the concentration of colchicine was better to be 120 mg·L-1 for chromosome doubling ofB. alnoides, and maximum chimaera number would be obtained in the regermination plantlet ofB. alnoides, after preculture without colchicine for 10 d and then co-culture with colchicine for 15 d.%以西南桦种子无菌萌发小苗的顶芽为外植体,探讨秋水仙素的浓度、处理时间及预培养时间对西南桦染色体加倍的影响,初步建立西南桦染色体加倍的方法。结果表明,使西南桦染色体加倍的秋水仙素浓度以120 mg·L-1为宜;在秋水仙素加倍处理前,预培养10 d后再加倍15 d效果较好,此时得到的西南桦嵌合体较多。

  14. Expression and Isolation of Phenylalanine Ammonia-lyase (PAL) Gene in Betula platyphylla%白桦苯丙氨酸解氨酶(PAL)基因的分离及其表达

    Institute of Scientific and Technical Information of China (English)

    宋福南; 邢磊; 陈肃; 戴超; 刘雪梅

    2009-01-01

    利用RT-PCR和RACE技术从白桦(Betula platyphylla)中克隆了编码苯丙氨酸解氨酶(PAL)的cDNA,其2322bp的ORF编码773个氨基酸,其推导的氨基酸序列包含PAL-HAL和PAL2个功能域以及酶活性中心序列GTITASGDLVPLSYIA,该序列同其它5种植物的序列一致性为60%~73%,其中与美洲红(Rhizophora mangle)树最高为73.1%.以该序列构建了系统进化树,白桦与美洲红树聚为一类,其余3种裸子植物长白松、沙地海岸松和银杏聚为一类.BplPAL1基因在各组织中均有不同的转录表达,在次生木质部表达最强,其次是幼叶,在花序中的表达量较低,说明BplPAL1基因在各组织中的调控和表达是不同的.

  15. 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.

  16. 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

  17. 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.

  18. 兴安白桦木材生长轮密度时间序列分析%Time Series Analysis of the Density of Wood Growth Ring for Betula platyphylla Suk.

    Institute of Scientific and Technical Information of China (English)

    刘春起

    2012-01-01

    In order to further improve the applicable value of the wood, time series analysis of the density of wood growth ring for Betula platyphylla Suk. was studied. To do this,21 sample trees were col- lected and analyzed by selecting the ARIMA (0, 1, 1) as the best model via AIC criterion. The result showed that the residuals were white noise sequence, and the average relative error of the prediction data was within 10%, indicating that the model had a good prediction result.%为进一步提高木材的实际应用价值,并为森林资源经营提供理论支持,对兴安白桦木材生长轮密度的径向变异进行研究。采集兴安白桦试样21株,对其生长轮密度的径向变化规律进行时间序列分析,依据最小信息量AIC原则,选择ARIMA(O,1,1)为最优模型;白噪声检验结果表明,残差序列为白噪声序列,模型诊断通过;序列预测值与实测值相对误差在10%之内,模型获得较好的预测效果。

  19. 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.

  20. 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

  1. 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.

  2. H2O2 Mediated Synthesis of Betulin in Cells of Betula platyphylla Induced by Fungal Elicitor%H2O2介导真菌诱导子促进白桦酯醇积累

    Institute of Scientific and Technical Information of China (English)

    孙美玲; 李晓灿; 王晓东; 詹亚光; 范桂枝

    2013-01-01

    The role of H2O2 in the synthesis of betulin in cells of birch (Betula platyphylla) induced by fungal elicitor was studied using suspension cell lines as the test materials.The results showed that the exogenously applied H2O2 decreased the cell viability and dry weight accumulation,however promoted the synthesis of betulin.Of them,the content of betulin was increased by 89.45% under treatment with 1 mmol·L-1 H2O2 for 12 h,and was increased by 73.72% under treatment with 0.1 mM H2O2 for 24 h.The fungal elicitor increased the synthesis of H2O2 and betulin by 391.67% and 185.22%,respectively.H2O2 scavenger catalase (CAT) significantly decreased induction effects of the fungal elicitor in H2O2 and betulin production in the birch cells and the contents reduced by 73.10% and 35.96%.The results suggested that H2O2 participated in the fungal elicitor-induced synthesis of betulin in birch cells.%以产白桦酯醇的白桦悬浮细胞系为试材,利用药理学试验,结合高效液相色谱和荧光显微镜技术,探讨过氧化氢(H2O2)在拟茎点霉属真菌诱导子促进白桦酯醇积累中的作用.结果表明:外源H2O2降低了细胞的活力和干质量的积累量,却提高了白桦酯醇的含量.其中,1 mmol· L-1H2O2处理12 h,白桦酯醇的含量比对照增加89.45%,0.1 mmol·L-1H2O2处理24 h,白桦酯醇的含量比对照增加73.72%.真菌诱导子促进了白桦悬浮细胞中H2O2和白桦酯醇的生成,在处理24 h时,分别比对照增加391.67%和185.22%.H2O2的清除剂过氧化氢酶减弱真菌诱导子对H2O2和白桦酯醇的诱导效应.由上述结果初步推断,H2O2参与了真菌诱导子诱导白桦酯醇积累的过程.

  3. Accumulation of Triterpenoids in Betula platyphylla Suspension Culture Induced by a Fungal Elicitor%真菌诱导子促进白桦悬浮细胞三萜的积累

    Institute of Scientific and Technical Information of China (English)

    翟俏丽; 范桂枝; 詹亚光

    2011-01-01

    Endophytic fungus of Phomopsis isolated from birch(Betula platyphylla) bark can be used as an elicitor to induce accumulation of triterpenoids in birch cell suspension culture. The change of dry weight and triterpenoids content of birch suspension cell were investigated at early growth phase, exponential growth phase and late growth phase after a fungal elicitor of 40, 100, and 400 (xg-mL"' concentration was added to birch suspension cells. Results showed that different induction schemes all promoted accumulation of triterpenoids, while the treatments reduced the dry weight of birch cells. Suspension cells at exponential growth phase were most easy to be induced, and 40 ng-mL"' fungal elicitor enhanced the triterpenoids content to 29. 47 mg-g"1, increasing by 789$j than that of the control. We investigated changes in pH and conductivity of the medium, and the activity of phenylalanine ammonialyase ( PAL) and peroxidase ( POD) under the optimal induction condition. Results showed that the fungal elicitor induced alkalinization of the medium and increased the conductivity, and significantly increased the activity of PAL and POD of birch suspension cells, which was 5. 70 and S. 74 fold as high as the control after 6 - 10 h of treatment, respectively. These results suggested that fungal elicitation induced defense reaction in birch suspension cell. General phenylpropanoid pathway and oxidative burst might involved in the triterpenoids accumulation induced by the fungal elicitor.%将促进白桦三萜积累的拟茎点霉属的内生真菌诱导子添加到白桦悬浮培养体系中,研究40,100,400pg·mL-1的真菌诱导子对生长初期、指数生长期和生长末期的悬浮细胞干质量和三萜积累的影响.结果表明:真菌诱导子的不同诱导方案均促进白桦悬浮细胞中三萜的积累,而细胞干质量积累却被抑制;其中最佳诱导条件为在指数生长期的白桦细胞中添加40 μg·mL-1的真菌诱导子诱导1天,诱导

  4. 西南桦苗木猝倒病生防菌的筛选及鉴定研究%Isolation and Identification of Damping-off Antagonist of Betula alnoides Seedlings

    Institute of Scientific and Technical Information of China (English)

    李娅; 朱潇逸; 景跃波; 庞静; 赵永红; 李翠萍; 曾郁珉; 伍建榕

    2013-01-01

    The tissue isolation and dilution-plate were used on healthy seedlings tissue , rhizosphere soil and coffee shell composting matrix for isolating antagonists of damping-off disease of Betula alnoides seedlings;and the isolated strains were identified through molecular method .The confront culture was conducted between 17 isolated strains and the pathogens Fusarium oxysporum and Fusarium solani to screen for antagonists .The results indicated that , the fungus strains 5#, 7#and bacteria BJ and JC1showed promising inhibition effects on two pathogens .The inhibi-tion rates of fungus strains 5# and 7# to the pathogens were 91.30 % and 90.12 % respectively , two bacteria strains had the inhibition belts of 0.4 cm and 0.5 cm, with the inhibition rates of 80.40%and 78.60% respec-tively , and BJ showed the better inhibition effect .The inhibition effects of two isolated fungal strains were better than bacterial strains .%采用组织分离法和稀释平板法对西南桦猝倒病发生区健康苗木组织、根际土壤及咖啡壳堆肥化基质进行菌种分离和分子鉴定。将分离获得的17株菌株与西南桦苗木猝倒病病原菌尖孢镰刀菌和腐皮镰刀菌进行平板对峙实验,筛选病原拮抗菌。结果表明,筛选出的真菌5#、7#及细菌 BJ、 JC1对西南桦苗木猝倒病原菌尖孢镰刀菌和腐皮镰刀菌具有较强抑制效果。其中真菌5#和7#的抑菌率分别为91.30%和90.12%;细菌BJ和JC1抑菌带较宽,对峙4天分别达0.4 cm和0.5 cm,抑菌率分别为80.4%和78.6%,且BJ抑菌效果更好;真菌与细菌比较,拮抗真菌5#和7#比拮抗细菌BJ和JC1抑制热区西南桦苗木猝倒病菌效果更好。通过对峙实验筛选出的5#、7#、 BJ和JC1拮抗菌,对热区防治苗木猝倒病及生防制剂的开发应用具有参考价值。

  5. System establishment of stem sections with a bud rapid propagation in Betula 'Royal Frost' and analysis on its influences%紫叶白桦茎芽快繁体系的建立及影响因素分析

    Institute of Scientific and Technical Information of China (English)

    杨玲; 沈海龙

    2012-01-01

    In order to develop a high-frequency plant regeneration system for Betula 'Royal Frost', taking young sterile stem section with a bud in vitro from B. 'Royal Frost' as explants, bud direct multiplication and plantlet regeneration experiments were conducted. The results showed that the optimal shoots proliferation medium was WPM medium (pH=5.4) supplemented with 0.2 μmol·L-1 6-BA and 20 g·L-1 sucrose, proliferation rate reached 10.4, and the shoots grew well. Shoots growing medium was WPM medium (pH=5.8) supplemented with 20 g·L-1 sucrose, and microshoots with 1.7 cm height and 0.89 mm of base diameter were conducted after 30 days. The microshoots became complete regenerated plantlet through exvitro rooting culture. Microshoots had the highest rooting rate of 91.5%, the most root number of 5.0, and the longest root length of 6.5 cm, in the medium with composition of 50% peat moss, 20% vermiculite and 30% pearlite. The regenerated plantlets well grew in the medium.%为建立高效的紫叶白桦组培快繁体系,以紫叶白桦试管内无菌带芽茎段作为外植体,进行芽直接增生途径的植株再生研究.结果表明:WPM+0.2 μmol·L-16-BA+20 g·L-1蔗糖(pH5.4)是适合紫叶白桦芽直接增生的增殖培养基,增殖率可达10.4,丛生芽生长状态好.WPM+20 g·L-1蔗糖(pH5.8)是适合丛生芽生长和增壮的培养基,在此培养基上培养30 d时,丛生芽可分化形成高1.7 cm、基径0.89 mm的微枝.微枝经过试管外生根培养可形成完整的再生植株.在草炭土、蛭石和珍珠岩以5:2:3体积比混合的生根基质中,微枝生根率最高(可达91.5%),不定根数量最多(5.0条),平均根长最长(6.5 cm).再生植株在上述相同基质中生长状况良好.

  6. Compatible Tree Biomass Models for Natural White Birch (Betula platyphylla) in Northeast China Forest Area%东北林区天然白桦相容性生物量模型

    Institute of Scientific and Technical Information of China (English)

    董利虎; 李凤日; 贾炜玮

    2013-01-01

    基于东北林区天然白桦实测生物量数据,通过2种方案(以总生物量为基础分级控制和以总生物量为基础直接控制)建立天然白桦一元和二元相容性生物量模型,模型参数估计采用非线性度量误差联立方程组估计方法,并采用加权回归的方法进行异方差的消除.结果表明:2种方案所建立的天然白桦一元、二元相容性生物量模型的确定系数R2 =0.800~0.988,模拟效率(EF) =0.80~0.97;2种方案所建立的相容性生物量模型的预测精度大多数在80%以上,树枝和树叶生物量模型的预测精度较差,但也在69%以上;所建立的相容性生物量模型中,总生物量和树干生物量模型效果较好,树根、树叶和树枝生物量模型效果较差.总的来说,2种方案所建立的相容性生物量模型都具有一定的精度,都能对天然白桦生物量进行很好的预估,以总生物量为基础直接控制方案所建立的一元和二元相容性生物量模型好于以总生物量为基础分级控制方案所建立的一元和二元相容性生物量模型,所以在进行天然白桦生物量预估时,建议采用以总生物量为基础直接控制所建立的相容性生物量模型.%Based on data of tree biomass for natural white birch (Betula platyphylla) in northeast China forest area,two methods (controlling jointly from level to level and controlling directly under total biomass) were used to establish the mono-element and dual-element compatible tree biomass model of natural white birch.And using nonlinear measurement error simultaneous equation estimated the parameters in the model,at the same time,the weighted regression was used to eliminate the heteroscedasticity.The results showed that R2 of mono-element and dual-element compatible model in this paper was 0.800-0.988,and the fit efficiency (EF) was 0.80-0.97.Besides,the precision of these models reached beyond 80%.On the other hand,the precision of foliage and

  7. Effects of remnant old-growth trees on other tree stems in a secondary Betula albosinensis-Abies faxoniana forest on the eastern edge of Qinghai-Xizang Plateau, China%青藏高原东缘红桦-岷江冷杉次生林中大径级保留木对其他林木的影响

    Institute of Scientific and Technical Information of China (English)

    李茂萍; 缪宁; 喻泓; 马姜明

    2014-01-01

    Aims As one of the biological legacies in degraded forest ecosystems after severe disturbance,remnant trees have many ecological effects in biodiversity maintenance and recovery of ecosystem structure and functioning.This study aims to understand the effects of remnant old-growth trees on other tree stems in a secondary Betula albosinensis-Abiesfaxoniana forest on the eastern edge of Qinghai-Xizang Plateau,China.Methods We established a 4 hm2 forest plot in a sub-alpine Betula albosinensis-Abiesfaxoniana stand in Miyaluo in western Sichuan,China.The species names,tree heights,diameters at breast height (DBH) (>1.3 m in height),and basal diameters (≥4 years,and ≤ 1.3 m in height) of all woody stems were recorded and the specific locations of all trees were mapped.Hegyi's competition index model was used to calculate the competition intensity between remnant old-growth trees and other dominant trees of different size-classes as well as the intra-and inter-specific competition intensity of the two dominant tree species,Abiesfaxoniana and Betula albosinensis.We used mark correlation functions kd(r) to explore the associations of the remnant old-growth trees with seedlings and saplings of A.faxoniana.Importantfindings The value of the inter-specific competition index (Hegyi's competition index (CI) =2.484) between B.albosinensis and A.faxoniana was significantly greater (p < 0.05) than the values of the intra-specific competition indices of B.albosinensis (CI =1.711) and A.faxoniana (CI =1.548).The value of the competition index between remnant old-growth trees and the small trees ofB.albosinensis was largest among the competition indices between the remnant old-growth trees and tree stems of different size-classes.The competition indices between remnant old-growth trees orB.albosinensis and small trees of A.faxoniana,between remnant old-growth trees and small trees of A.faxoniana and between remnant old-growth trees of A.faxoniana and small trees of B

  8. 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

  9. The Correlation Analysis of Soluble Sugar and Starch Contents with Electrical Impedance in Betula platyphylla Suk.Roots under Waterlogging and Flooding Stresses%涝渍胁迫下白桦根系可溶性糖和淀粉含量与电阻抗的相关性分析

    Institute of Scientific and Technical Information of China (English)

    孟昱; 邸葆; 张钢; 封新国; 徐成立; 田军

    2013-01-01

    以白桦(Betula platyphylla Suk.)2年生实生苗为材料,测定根系在涝渍胁迫下可溶性糖和淀粉含量与电阻抗图谱(electrical impedance spectroscopy,EIS)参数的变化,分析可溶性糖和淀粉含量与EIS参数的相关性.试验分对照、渍水和淹水3个处理组,处理时间为60d.结果表明:1)随着涝渍胁迫处理时间的延长,对照组可溶性糖含量呈整体缓慢上升趋势;渍水组呈先下降,后上升的趋势;淹水组呈先上升,后下降的趋势.2)随着涝渍胁迫处理时间的延长,对照和渍水组淀粉含量都呈整体上升的趋势;淹水组呈整体下降趋势.3)电阻抗图谱参数在涝渍胁迫处理期间均发生变化,且胞外电阻率(re)和弛豫时间(τ)的变化趋势相同.4)相关性分析结合通径分析表明,在涝渍胁迫期间,可溶性糖含量对re的影响最大,二者呈显著的正相关;淀粉含量对弛豫时间分布系数(Ψ)的影响最大,二者呈显著的负相关.说明电阻抗图谱参数能够有效地表征涝渍胁迫下白桦根系可溶性糖和淀粉的变化,电阻抗技术是研究林木根系在逆境胁迫下生理状况的一种有效方法.%Two-year-old seedlings of white birch (Betula platyphylla Suk.) were used to measure soluble sugar and starch contents as well as electrical impedance spectroscopy (EIS) parameters of roots under waterlogging and flooding stresses.The correlations of the EIS parameters with tested soluble sugar and starch contents were analyzed.Three treatments,the control,waterlogging and flooding,were carried out with duration of 60 days.The results showed that:1) Following the prolong of stress treatments time,soluble sugar content of the control decreased slowly; that of the waterlogging treatment decreased firstly,and increased later on; that of the flooding treatment increased firstly,and then decreased.2) Following the prolong of stress treatments time,starch content of the control and waterlogging treatments increased

  10. Short-term effects of fire disturbance on greanhouse gases emission from Betula platyphylla-forested wetland in Xiaoxing' an Mountains,Northeast China%火干扰对小兴安岭白桦沼泽温室气体排放的短期影响

    Institute of Scientific and Technical Information of China (English)

    牟长城; 张博文; 韩丽冬; 于丽丽; 顾韩

    2011-01-01

    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 ℃ 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 ℃ 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 summcr 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 > summcr 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

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

    Directory of Open Access Journals (Sweden)

    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. 真菌诱导子对白桦悬浮体系中N和P的吸收利用和三萜合成的影响%Effect of fungal elicitors on N and P utilization and triterpene synthesis of Betula platyphylla suspension cell culture system

    Institute of Scientific and Technical Information of China (English)

    王晓东; 李晓灿; 翟俏丽; 詹亚光; 范桂枝

    2011-01-01

    Objective To analyze the relationship of N and P utilization and triterpene synthesis in birch (Betula platyphylla) suspension cell culture system induced by fungal elicitor. Methods Fungal elicitors (40 ug/mL) were added to the 8-day-old birch suspension cell culture, the change of N and P and triterpene content were analyzed by chemical colorimetry. Results The dry weight, triterpene content, and triterpene yield of birch cell decreased with the extension of fungal treatment time. Among them, triterpene content and yield were the highest after 1 d fungal induction, they were 21.98 mg/g and 123.82 g/L, respectively, about two times of the control. The pH value and conductivity of birch cell culture also reached a peak after 1 d fungal treatment with increase by 6.10% and 8.20%, respectively. The contents of nitrate, ammonium, and phosphate increased after fungal treatment, but the content of phosphate was reduced after day 1 and 2 induction by 28.67% and 15.68%. The correlations between phosphate, ammonium, nitrate and triterpenoid contents in birch cell medium were improved significantly after fungal treatment. Conclusion It is reasoned that increased synthesis of triterpenes after fungal elicitors inducement may be related to the concentration changes of phosphate, ammonium, and nitrate.%目的 分析真菌诱导的白桦悬浮体系中N、P的吸收利用和三萜合成的关系.方法 在白桦悬浮细胞的生长末期添加40 μg/mL真菌诱导子,采用比色法分析真菌诱导后白桦悬浮体系中N、P和三萜量的变化.结果 白桦细胞的干质量、三萜量和产量随着真菌处理时间的延长表现为逐渐降低趋势.其中,三萜量和产量均于真菌诱导后第1天达到最高,分别为21.98 mg/g和123.82 g/L,约为对照的2倍;白桦悬浮体系的pH值和电导率在真菌诱导后第1天达到高峰,pH值增长了6.10%,电导率增加了8.20%;除细胞内磷酸根质量分数在诱导的第1、2天分别降低了28

  13. ДЕФИНИЦИЯ ДИССЕМИНАЦИИ INONOTUS OBLIQUUS (PERS.) PIL. ТИПОМ ЛЕСА BETULA-КОНСОРЦИИ, ОПРЕДЕЛЯЮЩИМ ИНТЕГРАЛЬНУЮ КОНСТЕЛЛЯЦИЮ

    OpenAIRE

    Баландайкин, М.

    2013-01-01

    Устанавливаются особенности влияния типа леса Betula pendula Roth. на степень встречаемости в сформированных насаждениях патологического агента Inonotus obliquus (Pers.) Pil.

  14. КОРРЕЛИРОВАНИЕ СОДЕРЖАНИЯ АСКОРБИНОВОЙ КИСЛОТЫ В АССИМИЛЯЦИОННОМ АППАРАТЕ BETULA PENDULA ROTH. С ДЕЙСТВИЕМ ПАТОЛОГИЧЕСКОГО АГЕНТА

    OpenAIRE

    Баландайкин, М.

    2014-01-01

    Рассматриваются особенности влияния совокупности антропогенных факторов и фитопатологического состояния дерева Betula pendula на концентрацию аскорбиновой кислоты в ассимиляционном аппарате. По критерию воздействия Inonotus obliquus (Pers.: Fr.) Pilat и присутствию поллютантов оценивалась адаптационная способность растения к действию стрессоров, а также возможность выработки механизмов, отвечающих за ингибирование биосинтеза аскорбиновой кислоты. Показано, что из всех проанализированных в дан...

  15. 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.

  16. 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.

  17. 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.

  18. Selective Solvents for Extraction of Triterpenes from Betula Pendula Outer Bark

    OpenAIRE

    Pāže, A; Zandersons, J; Rižikovs, J; Dobele, G.; Jurkjāne, V; Spince, B

    2013-01-01

    The volume of birch plywood production in Latvia is illustrated by the 208 000 m3 of plywood sold in 2011 and about 562 000 m3 of processed birch veneer blocks. Wood residues such as bark, veneer shorts, cut off ends and others are used as a fuel. It would be more expedient to increase the birch wood utilisation degree by involving also birch outer bark in the processing cycle. It makes up 2% of the veneer blocks’ mass. At the J.S.C. “Latvijas Finieris”, about 6000 t per year of graded and mi...

  19. Determining the age of young silver birch (Betula pendula Roth) trees growing on former agricultural

    OpenAIRE

    Tkaczyk, Miłosz; Tomusiak, Robert

    2013-01-01

    In Poland, according to the law (amendment of the act of 21st May 2010) – on the provision of information on the environment and its protection, public participation in environmental protection and environmental impact assessments etc. (Official Law Journal article 08.199.1227, as amended) – the owner can cut down trees without permission, if they do not exceed the age of 10 years old. However, if an owner happens to cuts down a tree on his property without knowing the age of the ...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    Olga V. Yatsenko; Igor O. Yatsenko

    2014-01-01

    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 cel...

  2. 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

    2014-02-01

    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.

  3. Elevated CO2 interacts with herbivory to alter chlorophyll fluorescence and leaf temperature in Betula papyrifera and Populus tremuloides.

    Science.gov (United States)

    Nabity, Paul D; Hillstrom, Michael L; Lindroth, Richard L; DeLucia, Evan H

    2012-08-01

    Herbivory can influence ecosystem productivity, but recent evidence suggests that damage by herbivores modulates potential productivity specific to damage type. Because productivity is linked to photosynthesis at the leaf level, which in turn is influenced by atmospheric CO(2) concentrations, we investigated how different herbivore damage types alter component processes of photosynthesis under ambient and elevated atmospheric CO(2). We examined spatial patterns in chlorophyll fluorescence and the temperature of leaves damaged by leaf-chewing, gall-forming, and leaf-folding insects in aspen trees as well as by leaf-chewing insects in birch trees under ambient and elevated CO(2) at the aspen free-air CO(2) enrichment (FACE) site in Wisconsin. Both defoliation and gall damage suppressed the operating efficiency of photosystem II (ΦPSII) in remaining leaf tissue, and the distance that damage propagated into visibly undamaged tissue was marginally attenuated under elevated CO(2). Elevated CO(2) increased leaf temperatures, which reduced the cooling effect of gall formation and freshly chewed leaf tissue. These results provide mechanistic insight into how different damage types influence the remaining, visibly undamaged leaf tissue, and suggest that elevated CO(2) may reduce the effects of herbivory on the primary photochemistry controlling photosynthesis.

  4. Effect of latitude and mountain height on the timberline (Betula pubescens ssp. czerpanovii elevation along the central Scandinavian mountain range

    Directory of Open Access Journals (Sweden)

    Arvid Odland

    2015-08-01

    Full Text Available Previously published isoline maps of Fennoscandian timberlines show that their highest elevations lie in the high mountain areas in central south Norway and from there the limits decrease in all directions. These maps are assumed to show differences in “climatic forest limits”, but the isoline patterns indicate that factors other than climate may be decisive in most of the area. Possibly the effects of ‘massenerhebung’ and the “summit syndrome” may locally have major effects on the timberline elevation. The main aim of the present study is to quantify the effect of latitude and mountain height on the regional variation of mountain birch timberline elevation. The study is a statistical analysis of previous published data on the timberline elevation and nearby mountain height. Selection of the study sites has been stratified to the Scandinavian mountain range (the Scandes from 58 to 71o N where the timberlines reach their highest elevations. The data indicates that only the high mountain massifs in S Norway and N Sweden are sufficiently high to allow birch forests to reach their potential elevations. Stepwise regression shows that latitude explains 70.9% while both latitude and mountain explain together 89.0% of the timberline variation. Where the mountains are low (approximately 1000 m higher than the measured local timberlines effects of the summit syndrome will lower the timberline elevation substantially and climatically determined timberlines will probably not have been reached. This indicates that models of future timberlines and thereby the alpine area extent in a warmer world may result in unrealistic conclusions without taking account of local mountain heights.

  5. 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.

  6. The pattern of intrapopulational and interpopulational changes of Betula pendula in Iran, based on leaf morphological traits

    OpenAIRE

    Mohammad Esmaeilpour Poodeh; Kambiz Taheri Abkenar; Ali Aalami; Amireslam Bonyad

    2014-01-01

    Despite superior medicinal properties of Birch, there aren’t any studies reported on its morphological diversity. For the first time, leaf samples were collected from four different sites, each site 10 trees and each tree 30 fertile and sterile shoots and leaves (totally 2400). In analyzing the mean values, the Siahmarz kuh showd the maximum and the Marmishoo minimum size mean. Angle of leaf base and number of veins had minimum and fluctuating asymmetry and distance border had a maximum coeff...

  7. The pattern of intrapopulational and interpopulational changes of Betula pendula in Iran, based on leaf morphological traits

    Directory of Open Access Journals (Sweden)

    Mohammad Esmaeilpour Poodeh

    2014-04-01

    Full Text Available Despite superior medicinal properties of Birch, there aren’t any studies reported on its morphological diversity. For the first time, leaf samples were collected from four different sites, each site 10 trees and each tree 30 fertile and sterile shoots and leaves (totally 2400. In analyzing the mean values, the Siahmarz kuh showd the maximum and the Marmishoo minimum size mean. Angle of leaf base and number of veins had minimum and fluctuating asymmetry and distance border had a maximum coefficient of variation, minimum and maximum morphological diversity respectively. Average size of sterile leaf traits was larger than average size of fertile leaf traits. It seemed that Siahmarz Kuh is had the most interapopulation diversity and could apply a transition source to sink. The slightest change in the veins of the population in birch was more strongly controlled by genes. Multivariate analyses of variance indicated high statistical significance of all factors: leaf type, population, type population, tree nested population and type × tree nested population. The cluster analysis identified three clusters, the first cluster contained only Marmishoo trees. Because the majority of the population, geographic distribution of genotypes was not consistent with the grouping that could be due to the influence of environmental factors on morphological traits, so it is recommended to use molecular markers. Canonical discriminant analysis showed that petiole length ratio and fluctuating asymmetry could be used in future research on morphological diversity among populations of B. pendula.

  8. 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

    2014-02-01

    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.

  9. 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.

  10. Cognition-enhancing and neuroprotective activities of the standardized extract of Betula platyphylla bark and its major diarylheptanoids.

    Science.gov (United States)

    Lee, Ki Yong; Jeong, Eun Ju; Huh, Jungmoo; Cho, Namki; Kim, Tae Bum; Jeon, Byung Ju; Kim, Seung Hyun; Kim, Hong Pyo; Sung, Sang Hyun

    2012-11-15

    Diarylheptanoids have been the center of the intensive research efforts for Alzheimer's disease and other neurodegenerative diseases. The present study aimed to determine the effect of the standardized extract of B. platyphylla bark and its major diarylheptanoids in scopolamine-induced amnesic mice through cyclic AMP response element-binding protein (CREB) activation. Oral administration of the standardized extract of B. platyphylla bark (100mg/kg body weight), aceroside VIII (1mg/kg body weight) and platyphylloside (1 or 2mg/kg body weight) significantly ameliorated scopolamine-induced amnesia in passive avoidance test. CREB phosphorylation and brain-derived neurotrophic factor (BDNF) expression in the cortex and hippocampus of the scopolamine-treated mice were markedly increased by the treatment of the standardized extract of B. platyphylla bark and platyphylloside. The standardized extract of B. platyphylla bark and its major diarylheptanoids also significantly protected HT22 cells against neurotoxicity induced by glutamate insult. The standardized extract of B. platyphylla bark and platyphylloside may ameliorate memory deficits by activating the CREB-BDNF pathway and prevent a neurodegeneration by inhibiting neuronal cell death.

  11. 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.

  12. 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.

  13. Interactive effects of elevated ozone and temperature on carbon allocation of silver birch (Betula pendula) genotypes in an open-air field exposure.

    Science.gov (United States)

    Kasurinen, Anne; Biasi, Christina; Holopainen, Toini; Rousi, Matti; Mäenpää, Maarit; Oksanen, Elina

    2012-06-01

    In the present experiment, the single and combined effects of elevated temperature and ozone (O(3)) on four silver birch genotypes (gt12, gt14, gt15 and gt25) were studied in an open-air field exposure design. Above- and below-ground biomass accumulation, stem growth and soil respiration were measured in 2008. In addition, a (13)C-labelling experiment was conducted with gt15 trees. After the second exposure season, elevated temperature increased silver birch above- and below-ground growth and soil respiration rates. However, some of these variables showed that the temperature effect was modified by tree genotype and prevailing O(3) level. For instance, in gt14 soil respiration was increased in elevated temperature alone (T) and in elevated O(3) and elevated temperature in combination (O(3) + T) treatments, but in other genotypes O(3) either partly (gt12) or totally nullified (gt25) temperature effects on soil respiration, or acted synergistically with temperature (gt15). Before leaf abscission, all genotypes had the largest leaf biomass in T and O(3) + T treatments, whereas at the end of the season temperature effects on leaf biomass depended on the prevailing O(3) level. Temperature increase thus delayed and O(3) accelerated leaf senescence, and in combination treatment O(3) reduced the temperature effect. Photosynthetic : non-photosynthetic tissue ratios (P : nP ratios) showed that elevated temperature increased foliage biomass relative to woody mass, particularly in gt14 and gt12, whereas O(3) and O(3) + T decreased it most clearly in gt25. O(3)-caused stem growth reductions were clearest in the fastest-growing gt14 and gt25, whereas mycorrhizal root growth and sporocarp production increased under O(3) in all genotypes. A labelling experiment showed that temperature increased tree total biomass and hence (13)C fixation in the foliage and roots and also label return was highest under elevated temperature. Ozone seemed to change tree (13)C allocation, as it decreased foliar (13)C excess amount, simultaneously increasing (13)C excess obtained from the soil. The present results suggest that warming has potential to increase silver birch growth and hence carbon (C) accumulation in tree biomass, but the final magnitude of this C sink strength is partly counteracted by temperature-induced increase in soil respiration rates and simultaneous O(3) stress. Silver birch populations' response to climate change will also largely depend on their genotype composition.

  14. Constitutive Model of Single Root System’s Resistance to Tensile Stress - Taking Pinus tabulaeformis, Betula platyphylla, Quercus mongolica and Larix gmelinii as Experimental Objects

    OpenAIRE

    Lihua Chen; Pinghua Wang; Yuanjun Yang; Jia He

    2014-01-01

    A constitutive model for the stress-strain relationship of single forest root system was developed in order to provide theoretical foundations for the mechanisms of soil-reinforcement by root system and offer a reliable basis for the analysis of root tensile strength character. This study started a general form of linear and non-linear stress-strain relation that was mathematically defined by four boundary conditions observed in typical tensile tests of single roots. The parameters of the mod...

  15. 紫叶白桦组培快繁技术研究%Research on Tissue Culture and Rapid Propagation in Betula ‘Royal Frost’

    Institute of Scientific and Technical Information of China (English)

    赵梦姝

    2016-01-01

    [目的]建立“紫叶白桦”组培快繁体系.[方法]选取当年生半木质化枝条的顶芽和侧芽为外植体进行芽直接增生途径再生研究.[结果]获取最佳外植体诱导培养基、最佳增殖培养基和最佳生根培养基,最佳移栽基质为蛭石+草炭(1∶1).[结论]为建立“紫叶白桦”组培快繁体系提供依据.

  16. 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

    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...

  17. 钾肥对白桦生理特性及三萜含量的影响%The Effects of Potassium Fertilizer on Physiological Characteristics and Triterpene Contents in Betula platyphylla Suk.

    Institute of Scientific and Technical Information of China (English)

    姬晓明; 齐凤慧; 尹静; 詹亚光

    2012-01-01

    为了研究钾肥对白桦防御酶及三萜含量的积累,从而建立生产三萜为目的的白桦栽培技术,建立钾肥调控三萜合成体系,以2年生白桦幼树为试材,通过施加高(15g/盆)、中(10g/盆)、低(5g盆)3种钾肥(KCI)对白桦进行处理,分析白桦叶片总三萜积累变化,同时对相关抗逆酶进行检测.结果表明,施用钾肥能够不同程度地提高白桦叶片中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)以及过氧化物酶(POD)的活性,并使叶片中可溶性糖含量增加,其中以中浓度钾肥效果最好,可使三萜含量达42.16 mg/(g·DW).在生长旺盛季节7-9月(哈尔滨),对白桦实施中浓度钾肥,可有效促进白桦叶片中三萜含量的积累.%In order to study the effects of potassium fertilizer on the activities of defensive enzymes and triterpene accumulation in the leaves of birch which paved the way for establishing a cultivating system of birch to produce triterpene via potassium application. 3 doses of potassium fertilizer (KC1), 15 g, 10 g and 5 g were applied to 2-year seedlings. Then the content of triterpene and the activity of defensive enzymes were determined by a spectrophotometer. The results showed that potassium fertilizer raised the activity of SOD, CAT and POD to different extent, respectively. The content of soluble sugar within the leaves also rose. Among the three doses, the mediate one (5 g) brought the best effect to triterpene accumulation [up to 42.16 mg/(g ? DW)]. Mediate potassium could effectively promote the accumulation of triterpene within the leaves of birch when were fertilized during the seasons for fast growing (from July to September in Harbin).

  18. 白桦细胞悬浮培养产三萜及其营养成分消耗的动态%Kinetics of Triterpenoid Production and Nutrient Consumption in Birch (Betula platyphylla) Suspension Cell p

    Institute of Scientific and Technical Information of China (English)

    范桂枝; 翟俏丽; 于海娣; 王晓东; 王博; 詹亚光

    2011-01-01

    Effects of the basic media and inoculum size on birch cell growth and the triterpenoid production were investigated using birch suspension cells, on this basis, the kinetic relationships of birch cell growth, triterpenoid production and nutrient consumption were also analyzed. The results showed the opbimal conditions for the birch cell growth and triterpenoid production were 20 ~ 30 g· L-1(FW) of inoculum size, in B5 medium. The kinetics analysis for birch cell suspension culture showed that triterpenoid production was increasing with the birch cell growth during a cell subculture cycle. During the teriod, the maximum specific growth rate was 0. 18 on the 12th day, and the maximum triterpenoid synthesis rate was 0.73 mg· g-1 on the 9th day. Sugar, NO3- , NH+4 and PO34- in the culture medium were nearly used up on the 9th day, The content of sugar, NO-3 , and PO34- in birch cell were highest on 6th day, but the content of NH+4 in birch cell were higher on 3th day. The results snggested that the nutrient deficiencies in medium wonld limited the cell rapid multiplication and triterpenoid content accumulation.%以产三萜的白桦悬浮系为试验材料,在优化白桦悬浮细胞生长与三萜积累的培养基种类和接种量的基础上,分析白桦悬浮细胞生长和三萜积累的动力学关系,同时考察1个培养周期内白桦细胞内外主要营养成分的变化.结果表明:1)在MS,NT,IS,WPM,1/2MS,B5 6种培养基和10~40 g·L-1接种量中,有利于白桦细胞生长和三萜生产的培养基为B5和接种量为20~30 g·L-1 FW;2)在1个培养周期内,白桦悬浮细胞培养过程中三萜的产量与细胞生物量是相偶联的,随着生物量的增加三萜产量呈增长趋势,其中,白桦细胞在第12天比生长速率达到最高0.18,三萜合成速率和比合成速率在第9天达到最高值,分别为0.73 mg·g-1和0.06;3)在白桦细胞培养的1个周期内,培养液中的蔗糖,NO3,NH+4和PO3-4在细胞培养的第9天基本被消耗掉,而细胞内的营养物质,除NH4+在第3天达最高值外,其他营养成分均在第6天达最大值.由此可推断:培养液中营养成分的不足限制了细胞的快速增值和三萜含量的提高.

  19. Effects of Water,Nitrogen and Methyl Jasmonate Treatment on Triterpenes Accumulation in Birch (Betula platyphylla Suk.)%水分、氮肥及MeJA处理对白桦三萜积累特性的影响

    Institute of Scientific and Technical Information of China (English)

    李春晓; 尹静; 詹亚光; 任春林; 王智慧

    2012-01-01

    With one year and a half birch saplings as experimental materials, we investigated the effects of water,nitrogen and methyl jasmonate(MeJA) treatment on the accumulation of triterpenes and the accumulated regulation of triterpenes in birch. The results showed that,total triterpene is mainly distributed in stem bark and leaf in birch sapling,the average content is 71. 94 mg · G-1 and 81. 60 mg · G-1 respectively, and the lowest in root bark, which is 25. 45 mg · G-1. The accumulated peak of total triterpene in leaf is June and July;But accumulated peaks of total triterpene in stem bark and root bark are August and July, respectively. Moderate and severe drought stress had significantly contributed to the accumulation of total triterpene in leaf in the early stage of drought stress,which are 1. 24 and 1. 27 times of the control. The accumulation of total triterpene for water stress in stem bark is significantly higher than at of control in July.Water stress has not conducived to total triterpene accumulation of the stem bark in other months. In addition, drought stress is adverse to triterpene accumulation in the root bark. Nitrogen treatment in early stage (June) is not conducive to triterpenoids accumulation in the leaves and root bark,but has remarkably contributed to the triterpenoids accumulation in late stage (July-October). However, the nitrogen treatment has contributed to the triterpenoids accumulation in the stem bark in early stage (June-July). MeJA spraying has promoted the triterpenes accumulation in the leaf and root bark. In the accumulating peak stage, with 1. 52 and 1. 42 times of the control. Light drought, nitrogen fertilizer both contribute to height growth and biomass accumulation of birch saplings, but MeJA treatment is disadvantage on the whole plant bio-mass accumulation.%以一年半生白桦幼树为试材,研究水分、氮肥和茉莉酸甲酯(MeJA)处理对白桦三萜物质积累的影响,并对白桦植株中三萜积累规律进行了探讨.结果表明:(1)白桦幼树植株中总三萜主要分布在茎皮和叶片,根皮中最低,平均含量分别为71.94、81.60和25.45 mg?g-1;叶片中总三萜积累高峰出现在6、7月份,茎皮和根皮中总三萜积累高峰分别出现在8月份和7月份.(2)干旱胁迫早期(6月)中度和重度干旱胁迫显著促进了叶中总三萜积累,分别是对照的1.24和1.27倍.茎皮中,除7月水分胁迫处理显著高于对照外,其它各月份水分胁迫不利于茎皮中总三萜含量积累,干旱胁迫不利根皮中三萜积累.(3)施氮早期(6月)不利于三萜在叶片和根皮中积累,中后期(7~10月),氮肥处理对三萜积累有显著促进作用;而施氮早期(6~7月)促进茎皮中三萜积累作用.(4) MeJA喷施处理对叶片和根皮中三萜积累(7月~10月)均具有显著的促进作用,在积累高峰期分别是对照的1.42倍和1.52倍.(5)轻度干旱、氮肥均促进了白桦幼树株高的增长和生物量的积累,而MeJA处理对整株生物量的积累不利.

  20. Estrés oxidativo y respuestas fisiológicas a la acumulación de metales pesados en Betula celtiberica micorrizada y no micorrizada cultivada en un suelo contaminado

    OpenAIRE

    Murube Torcida, Ester Maria

    2014-01-01

    Los metales pesados no son biodegradables lo que hace que sean contaminantes muy persistentes en el medio ambiente, lo que supone un grave riesgo no sólo para la salud medioambiental sino también para la salud humana. La fitorremediación se presenta como una alternativa biológica sencilla y viable en la descontaminación de suelos; sin embargo, está influenciada por la biodisponibilidad de los metales pesados en el suelo así como por su toxicidad y por las actividades microbianas de la rizosfe...

  1. 以光合效率度量天然白桦种群生态位初探%Primary Probing into Niche of Natural Betula platyphylla Population by Means of Photosynthetic Efficiency

    Institute of Scientific and Technical Information of China (English)

    王爱民; 祖元刚

    2002-01-01

    In terms of photosynthetic efficiency,which demonstrates the space-time function of plant,niche width of B. Platyphylla population was described.First,on the basis of net photosynthetic amount in certain time,the niche width of a birch was calculated.Then,the realized niche and rudimental niche of B. Platyphylla seedlings,young trees and adult trees were discussed.Finally, the dynamic of niche under special conditions was studied.

  2. Cloning and ;activity analysis of BpGT14 gene promoter in Betula platyphylla%白桦BpGT14基因启动子克隆及表达活性分析

    Institute of Scientific and Technical Information of China (English)

    李蕾蕾; 孙丰坤; 李天宇; 寇萍; 詹亚光; 曾凡锁

    2016-01-01

    本文利用SiteFinding-PCR方法克隆了白桦BpGT14基因起始密码子ATG上游2169 bp序列,并通过PLACE启动子预测工具对其进行元件分析。结果表明,该启动子片段含有启动子核心元件及多种逆境及激素响应元件,同时具有植物苯丙烷及木质素生物合成的MYB类转录因子的重要结合基序。研究选取了其中含有启动子核心元件的1156 bp片段构建了pBpGT14宜GUS植物表达载体,利用农杆菌侵染的方法将pBpGT14::GUS报告基因瞬时转化烟草植株,鉴定该启动子在烟草中的表达活性及对非生物胁迫和激素的响应模式。对转基因烟草植株进行GUS染色,结果表明该启动子具有启动活性,且在茎段处活性较高;进一步分析非生物胁迫对烟草中GUS酶活性的影响,表明该启动子对ABA、NaCl、PEG及高温处理均有明显响应,且对于NaCl及PEG处理响应迅速。为了更好的鉴定白桦BpGT14基因启动子在白桦细胞中的启动活性及响应模式,本文构建了pBpGT14宜GFP载体并瞬时转化白桦茎段悬浮细胞,进行研究。 GFP转录水平分析结果与GUS酶活性结果基本一致,但其中部分时间点仍存在差异。选取PEG处理3、6、12及24 h的转GFP基因白桦茎段悬浮细胞,在显微镜下观察其绿色荧光蛋白,以此揭示该启动子对干旱的响应模式。结果表明,该启动子在白桦茎段悬浮细胞中启动了GFP的表达,在处理初期(3 h),荧光效果明显;随着处理时间的增加,细胞脱水明显,且在细胞壁表现高亮度荧光。%We cloned a 2 169 bp promoter sequence of BpGT14 gene from birch genomic DNA using the method of SiteFinding-PCR. The promoter sequence was analyzed by PLACE, and the result showed that this fragment contained promoter core elements and some elements which can respond to abiotic stress and hormones. Meanwhile, two important MYB transcription factor binding elements were found which regulate phenylpropanoid and lignin biosynthesis. To study the promoter activity, a 1 156 bp fragment was chosen to construct pBpGT14::GUS plant expression vector and transformed into tobacco. GUS staining proved that the promoter had high activity in stem segments. When the tobacco was treated with GA and H2 O2 at 4℃, the promoter had no significant response and the enzyme activity had a downward trend. In contrast, the promoter activity was significantly increased by ABA, NaCl, PEG and 37 ℃ treatment. Further transformation of birch cells using pBpGT14宜GFP plant expression vector indicated that the promoter had a similar response pattern to that of tobacco treated with abiotic stress and hormone except for a few time points. As the promoter was significantly and quickly responsive to drought stress, we have observed the GFP fluorescence protein in birch stem segments suspension cells transformed by GFP for 3 , 6, 12 and 24 h with PEG treatment. The results showed that BpGT14 promoter had activity in birch stem segments suspension cells and fluorescence can be observed in the suspension cells, especially in cell walls. Successful implementation of this study has important significance for analysis of gene regulation and function. Meanwhile, it provides a theoretical basis for gene promoter function studies of other woody plants.

  3. The Effect of Sodium Nitrite and Arginine on the Biosynthesis of Nitric Oxide and Triterpenoid in Birch (Betula platyphylla Suk) Suspension Cells%亚硝酸钠和精氨酸对白桦悬浮细胞中NO和三萜合成的影响

    Institute of Scientific and Technical Information of China (English)

    许道琦; 张杰琨; 王晓东; 詹亚光; 范桂枝

    2012-01-01

    The aim was to analyze the relation of nitric oxide (NO) and triterpenoid production. Sodium nitrite and arginine were added in the eight-day-old birch suspension cell culture, the change of triterpene content and NO content were analyzed by chemical colorimetry and fluorescence microscopy. NO and triterpenoid content were increased by 500 μg/L and 100 μg/L sodium nitrite and arginine, and the higher increasing was induced by 500 μg/L sodium nitrite and arginine. The content of NO and triterpenoid in birch cells induced by 500 μg/L sodium nitrite was higher than that of 500 μg/L arginine, the increasing rate of triterpenoid was 1.5 times. Inhibitor of NaN3 and L-NAME decreased the effect of sodium nitrite and arginine on the biosynthesis of NO and triterpenoid, the content of NO and triterpenoid were near to the level of control. These results preliminary indicated that NR and NOS were involved in triterpenoids biosynthesis in birch suspension culture, and NR might be play an important role in triterpenoids biosynthesis.%旨在分析亚硝酸钠和精氨酸处理12h后白桦悬浮细胞中一氧化氮(NO)和三萜含量的变化.在白桦悬浮细胞的生长末期添加硝酸还原酶(NR)和一氧化氮合成酶(NOS)的底物亚硝酸钠和精氨酸,采用比色法和荧光显微镜方法分析白桦悬浮体系中三萜含量和NO含量的变化.500 μg/L和100 μg/L的亚硝酸钠和精氨酸均促进了白桦悬浮细胞中NO和三萜的合成,其中500μg/L的亚硝酸钠和精氨酸促进作用最强.500μg/L亚硝酸钠处理下白桦细胞中的NO荧光强度和三萜含量均高于500μg/L精氨酸处理,其中三萜含量增加了1.5倍.将NR和NOS的抑制剂NaN3和L-NAME分别添加到亚硝酸钠和精氨酸处理的白桦悬浮体系中,发现亚硝酸钠和精氨酸对NO和三萜合成的促进作用被抑制了.NR和NOS来源途径的NO参与了白桦三萜的合成,可能NR来源途径的贡献大于NOS途径.

  4. Phylogeographic patterns in Leccinum sect. Scabra and the status of the arctic/alpine species L. rotundifoliae

    NARCIS (Netherlands)

    Bakker, den H.C.; Zuccarello, G.C.; Kuyper, T.W.; Noordeloos, M.E.

    2007-01-01

    We investigated inter- and intraspecific phylogenetic relationships in the ectomycorrhizal fungal genus Leccinum section Scabra. Species of this section are exclusively associated with Betula and occur throughout the Northern Hemisphere. We compared the phylogenetic relationships of arctic, alpine,

  5. A NEW SPECIES OF THE GENUS KUWANINA FROM CHINA(HEMIPTERA,COCCOIDEA, ERIOCOCCIDAE)%中国隙毡蚧属一新种(半翅目,蚧总科,毡蚧科)

    Institute of Scientific and Technical Information of China (English)

    武三安; 刘锦

    2009-01-01

    A new species of genus Kuwanina K.beula sp, nov., collected on Betula ablo-sinensis from Henan Province of China, is described and illustrated. A key to species of the world is provided. Type specimens are deposited in the Insect Collection, Beijing Forestry University.%记述采自我国河南省嵩县白云山红桦 Betula ablosinensis上的隙毡蚧属1新种:红桦隙毡蚧Kuwanina betula sp.nov..同时给出了该属分种检索表.模式标本保存在北京林业大学昆虫标本室.

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

    OpenAIRE

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

    2008-01-01

    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 R...

  7. Life-history strategies affect aphid preference for yellowing leaves.

    Science.gov (United States)

    Holopainen, Jarmo K; Semiz, Gürkan; Blande, James D

    2009-10-23

    According to the nutrient-translocation hypothesis, yellowing tree leaves are colonized by aphids at the end of the growing season owing to improved availability of nutrients in the phloem sap after chlorophyll degradation. We measured aphid densities on potted Betula pendula seedlings in a field site where a small proportion of foliage rapidly turned yellow before normal autumn coloration as a consequence of root anoxia. The number of adults and nymphs of the birch-feeding specialist aphids Euceraphis betulae, Betulaphis brevipilosa and Callipterinella tuberculata were counted from leaves on each of the 222 plants. Aphids were detected on 19 per cent of green leaves and on 41 per cent of yellow leaves. There was no indication of aphid avoidance of yellow leaves, and the number of winged (alate) viviparous E. betulae adults and their nymphs were significantly higher on yellow leaves than on green leaves, while the numbers of apterous B. brevipilosa and C. tuberculata did not differ between the leaf colour types. Our result suggests that only aphid species with alate generation during colour change can take advantage of yellowing leaves. This may explain the exceptional abundance of E. betulae compared with other aphid species on birches. PMID:19535364

  8. Shading and root-shoot relations in saplings of silver birch, pedunculate oak and beech

    NARCIS (Netherlands)

    Hees, van A.F.M.; Clerkx, A.P.P.M.

    2003-01-01

    Silver birch (Betula pendula Roth), pedunculate oak (Quercus robur L.) and beech (Fagus sylvatica L.) can regenerate successfully under a canopy of Scots pine (Pinus sylvestris L.). Shading reduces plant growth and modifies plant form, two related aspects. This study focuses on the effects of shadin

  9. AcEST: DK957328 [AcEST

    Lifescience Database Archive (English)

    Full Text Available ha tubulin OS=Betula verrucosa PE=2 SV=1 332 2e-89 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN...TGSGLGSLLLERLSVDYGKKSKLGFTVYPSPQVST 179 >tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson

  10. AcEST: DK963239 [AcEST

    Lifescience Database Archive (English)

    Full Text Available lin OS=Betula verrucosa PE=2 SV=1 328 2e-88 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson...SGLGSLLLERLSVDYGKKSKLGFTVYPSPQV 177 >tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=

  11. Flynn Effects on Sub-Factors of Episodic and Semantic Memory: Parallel Gains over Time and the Same Set of Determining Factors

    Science.gov (United States)

    Ronnlund, Michael; Nilsson, Lars-Goran.

    2009-01-01

    The study examined the extent to which time-related gains in cognitive performance, so-called Flynn effects, generalize across sub-factors of episodic memory (recall and recognition) and semantic memory (knowledge and fluency). We conducted time-sequential analyses of data drawn from the Betula prospective cohort study, involving four age-matched…

  12. 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

  13. Effective height development of four co-occurring species in the gap-phase regeneration of Douglas fir monocultures under nature-oriented conversion. Forest Ecology and Management, Pages 189-198

    NARCIS (Netherlands)

    Dekker, M.; Breugel, van M.; Sterck, F.J.

    2007-01-01

    Natural regeneration in gaps in Douglas fir forest stands in the Netherlands mainly consists of Betula pendula (Roth.), Pinus sylvestris (L.), Larix kaempferi (Carr.), and Pseudotsuga menziesii (Mirb. Franco). Even though these species are well known, the autogenic development of these species in an

  14. Cytotoxicity of natural ginseng glycosides and semisynthetic analogues

    NARCIS (Netherlands)

    Atopkina, LN; Malinovskaya, GV; Elyakov, GB; Uvarova, NI; Woerdenbag, HJ; Koulman, A; Potier, P

    1999-01-01

    The cytotoxicity of natural glycosides from Ginseng, semisynthetic analogues and related triterpenes of the dammarane series, isolated from the leaves of the Far-East species of the genus Betula was studied in order to elucidate structure-activity relationships. Some of the compounds studied were ac

  15. How to measure distinct components of visual attention fast and reliably

    DEFF Research Database (Denmark)

    Vangkilde, Signe Allerup; Kyllingsbæk, Søren; Habekost, Thomas;

    2009-01-01

    for the Swedish Betula-project, a longitudinal study investigating changes in cognitive functions over the adult life span (Nilsson et al., 2004). The test consists of a computer-based letter recognition task with stimulus displays of varied durations followed by pattern masks or a blank screen. The temporal...

  16. Expansion of invasive species on ombrotrophic bogs: desiccation or high N deposition?

    NARCIS (Netherlands)

    Tomassen, H.B.M.; Smolders, A.J.P.; Limpens, J.; Lamers, L.P.M.; Roelofs, J.G.M.

    2004-01-01

    1. In many ombrotrophic bog areas the invasion of grass (e.g. Molinia caerulea) and tree (e.g. Betula pubescens) species has become a major problem. We investigated whether the invasion of such species is due to high atmospheric nitrogen (N) deposition by conducting a fertilization experiment. 2. Th

  17. 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 ...

  18. Spatial interactions between ungulate herbivory and forest management

    NARCIS (Netherlands)

    Kramer, K.; Groot Bruinderink, G.W.T.A.; Prins, H.H.T.

    2006-01-01

    The SE-Veluwe is a forested area in The Netherlands consisting mainly of Pinus and heathlands and includes mono- and mixed species stands of Fagus sylvatica, Quercus robur, Q. petraea, Picea abies, Pseudotsuga menziesii, Betula pubescens and B. pendens. In this area, forest managers differ in manage

  19. Books received by the Rijksherbarium library

    NARCIS (Netherlands)

    NN,

    1992-01-01

    The fifth issue of this series comprises extended keys for the determination of 148 species of Ectomycorrhizae (Abies 1, Betula 17, Carpinus 1, Fagus 31, Larix 10, Picea 51, Pinus 33, Pseudotsuga 4, and Quercus 2). The glossary, synoptic tables, literature as well as proposals for the arrangement of

  20. 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

  1. A Greener Arctic: Vascular Plant Litter Input in Subarctic Peat Bogs Changes Soil Invertebrate Diets and Decomposition Patterns

    Science.gov (United States)

    Krab, E. J.; Berg, M. P.; Aerts, R.; van Logtestijn, R. S. P.; Cornelissen, H. H. C.

    2014-12-01

    Climate-change-induced trends towards shrub dominance in subarctic, moss-dominated peatlands will most likely have large effects on soil carbon (C) dynamics through an input of more easily decomposable litter. The mechanisms by which this increase in vascular litter input interacts with the abundance and diet-choice of the decomposer community to alter C-processing have, however, not yet been unraveled. We used a novel 13C tracer approach to link invertebrate species composition (Collembola), abundance and species-specific feeding behavior to C-processing of vascular and peat moss litters. We incubated different litter mixtures, 100% Sphagnum moss litter, 100% Betula leaf litter, and a 50/50 mixture of both, in mesocosms for 406 days. We revealed the transfer of C from the litters to the soil invertebrate species by 13C labeling of each of the litter types and assessed 13C signatures of the invertebrates Collembola species composition differed significantly between Sphagnum and Betula litter. Within the 'single type litter' mesocosms, Collembola species showed different 13C signatures, implying species-specific differences in diet choice. Surprisingly, the species composition and Collembola abundance changed relatively little as a consequence of Betula input to a Sphagnum based system. Their diet choice, however, changed drastically; species-specific differences in diet choice disappeared and approximately 67% of the food ingested by all Collembola originated from Betula litter. Furthermore, litter decomposition patterns corresponded to these findings; mass loss of Betula increased from 16.1% to 26.2% when decomposing in combination with Sphagnum, while Sphagnum decomposed even slower in combination with Betula litter (1.9%) than alone (4.7%). This study is the first to empirically show that collective diet shifts of the peatland decomposer community from mosses towards vascular plant litter may drive altered decomposition patterns. In addition, we showed that

  2. Spruce forests (Ass. Sphango girgensohnii - Piceetum (Br.-Bl. 39 Polak. 62 on excessively moistened peatlands in Latvia

    Directory of Open Access Journals (Sweden)

    Normunds Priedits

    2014-02-01

    Full Text Available The research carried out on swamp spruce forests on peatland in Latvia gives a detailed notion of the phytosociological structure of Ass. Sphagno girgensohnii - Piceetum (Br. - BI. 39 Polak. 62 in the western part of the East-European Plain at the Baltic Sea. The paper reflects one of the aspects of swamp forest investigation results in Latvia on forest communities, its biodiversity and presevation. Ninety-one sample plots with Picea abies as the dominant in the tree layer or co-dominant with Betula pendula, Betula pubescens or Pinus sylvestris are described according to phytosociological Braun-Blanquet methodology. Floristic features of spruce communities belonging to Caricoso-phragmitosa and Dryopterioso-cnricosa forest site types are analysed. The results are compared with similar investigations carried out in the Baltic Sea region states and neighbouring countries.

  3. Pulse Pressure magnifies the effect of COMT Val158Met on 15 Year Episodic Memory Trajectories

    OpenAIRE

    Persson, Ninni; Lavebratt, Catharina; Sundström, Anna; Fischer, Håkan

    2016-01-01

    We investigated whether a physiological marker of cardiovascular health, pulse pressure (PP), and age magnified the effect of the functional COMT Val158Met (rs4680) polymorphism on 15-years cognitive trajectories [episodic memory (EM), visuospatial ability, and semantic memory] using data from 1585 non-demented adults from the Betula study. A multiple-group latent growth curve model was specified to gauge individual differences in change, and average trends therein. The allelic variants showe...

  4. Life-history strategies affect aphid preference for yellowing leaves

    OpenAIRE

    Holopainen, Jarmo K.; Semiz, Gürkan; Blande, James D

    2009-01-01

    According to the nutrient-translocation hypothesis, yellowing tree leaves are colonized by aphids at the end of the growing season owing to improved availability of nutrients in the phloem sap after chlorophyll degradation. We measured aphid densities on potted Betula pendula seedlings in a field site where a small proportion of foliage rapidly turned yellow before normal autumn coloration as a consequence of root anoxia. The number of adults and nymphs of the birch-feeding specialist aphids ...

  5. ACCUMULATION OF HEAVY METALS IN LEAF LITTER OF DIFFERENT TREE SPECIES IN URBAN AREAS

    OpenAIRE

    Konoshina, S.; Khilkova, N.

    2015-01-01

    Analysis of heavy metal accumulation of leaf litter of woody plants: Aesculus hippocastanum Aesculus hippocastanum, heart-shaped linden Tilia cordata, Siberian larch Larix sibirica, mountain ash Sorbus aucuparia, warty birch Betula verrucosa, growing within Orel City is given. The kinds of woody plants, which leaf litter has the largest accumulation of heavy metals are determined. The maximum total content of heavy metals in leaf litter was observed in mountain ash and birch.

  6. AcEST: DK955920 [AcEST

    Lifescience Database Archive (English)

    Full Text Available Alpha tubulin OS=Betula verrucosa PE=2 SV=1 296 7e-79 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilso... Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=1 Length = 451 Score = 296 bits (757), Expect = 7e-79 Ident...RIRKLADNCTGLQGFLVFNAV 519 RIRKLADNCTGLQGFLVFNAV Sbjct: 121 RIRKLADNCTGLQGFLVFNAV 141 >tr|A9QVH4|A9QVH4_9CONI

  7. AcEST: DK956633 [AcEST

    Lifescience Database Archive (English)

    Full Text Available tubulin OS=Betula verrucosa PE=2 SV=1 350 5e-95 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson... Sbjct: 181 VVEPYNSVLS 190 >tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=1 Length

  8. AcEST: DK959506 [AcEST

    Lifescience Database Archive (English)

    Full Text Available bulin OS=Betula verrucosa PE=2 SV=1 374 e-102 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson... 201 >tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=1 Length = 451 Score = 374 bits

  9. AcEST: DK952919 [AcEST

    Lifescience Database Archive (English)

    Full Text Available TIW7_BETVE Alpha tubulin OS=Betula verrucosa PE=2 SV=1 358 1e-97 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson...LSTHS 658 VVEPYNSVLSTHS Sbjct: 181 VVEPYNSVLSTHS 193 >tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson

  10. AcEST: DK955655 [AcEST

    Lifescience Database Archive (English)

    Full Text Available in OS=Betula verrucosa PE=2 SV=1 259 4e-68 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 P....A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=1 Length = 45

  11. AcEST: DK958049 [AcEST

    Lifescience Database Archive (English)

    Full Text Available TVE Alpha tubulin OS=Betula verrucosa PE=2 SV=1 346 8e-94 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson...A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=1 Length = 451 Score = 346 bits (887), Expect =

  12. AcEST: DK961804 [AcEST

    Lifescience Database Archive (English)

    Full Text Available n OS=Betula verrucosa PE=2 SV=1 292 1e-77 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson...TGSGLGSLLLERLSVDYGKKSKLGFTVY 172 >tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=1 L

  13. AcEST: DK951921 [AcEST

    Lifescience Database Archive (English)

    Full Text Available |B7TIW7_BETVE Alpha tubulin OS=Betula verrucosa PE=2 SV=1 329 7e-89 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson...GSGLGSLLLERLSVDYGKKSKLGFTVYPSP 175 >tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=1

  14. AcEST: DK948361 [AcEST

    Lifescience Database Archive (English)

    Full Text Available 7_BETVE Alpha tubulin OS=Betula verrucosa PE=2 SV=1 400 e-110 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson...STHSLLEHTDVAVLLDNEAIYDICR 214 >tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=1 Leng

  15. AcEST: DK954985 [AcEST

    Lifescience Database Archive (English)

    Full Text Available tubulin OS=Betula verrucosa PE=2 SV=1 339 7e-92 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TU...KKSKLGFTVYPSPQVSTS 180 Query: 633 V 635 V Sbjct: 181 V 181 >tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson

  16. AcEST: DK956379 [AcEST

    Lifescience Database Archive (English)

    Full Text Available B7TIW7_BETVE Alpha tubulin OS=Betula verrucosa PE=2 SV=1 350 3e-95 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson...ALNVDVTEFQTN 258 >tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1

  17. AcEST: DK963473 [AcEST

    Lifescience Database Archive (English)

    Full Text Available lin OS=Betula verrucosa PE=2 SV=1 325 1e-87 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 P...RKLADNCTGLQGFLVFNAVGGGTGSGLGSLLLERLSVDYGKKSKLGFTVYP 173 >tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wil...sonii GN=TUA1 PE=2 SV=1 Length = 451 Score = 325 bits (833), Expect = 1e-87 Identit

  18. AcEST: DK949329 [AcEST

    Lifescience Database Archive (English)

    Full Text Available a tubulin OS=Betula verrucosa PE=2 SV=1 335 2e-90 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson...637 V 639 V Sbjct: 181 V 181 >tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=1 Lengt

  19. AcEST: DK963606 [AcEST

    Lifescience Database Archive (English)

    Full Text Available W7_BETVE Alpha tubulin OS=Betula verrucosa PE=2 SV=1 333 5e-90 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson..._9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=1 Length = 451 Score = 333 bits (854), Expect = 5e-90

  20. AcEST: DK959840 [AcEST

    Lifescience Database Archive (English)

    Full Text Available B7TIW7|B7TIW7_BETVE Alpha tubulin OS=Betula verrucosa PE=2 SV=1 333 6e-90 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilson...QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=1 Length = 451 Score = 333 bits (854), Exp

  1. AcEST: DK954281 [AcEST

    Lifescience Database Archive (English)

    Full Text Available e-92 tr|B7TIW7|B7TIW7_BETVE Alpha tubulin OS=Betula verrucosa PE=2 SV=1 341 3e-92 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilso...>tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=1 Length = 451 Score = 341 bits (874

  2. Plant and insect diversity along an experimental gradient of larch-birch mixtures in Chinese boreal forests

    OpenAIRE

    Li, Jing; Shi, Juan; Luo, Youqing; HELIÖVAARA, Kari

    2012-01-01

    Maintaining and increasing biodiversity level especially in pure plantations is one important way to improve the resistance of forests to pests in Chinese boreal forests. The present study tested the hypothesis that the increased degree of tree species mixture (quantified by the stem proportion of Betula platyphylla Suk. and Larix gmelinii (Rupr.) Rupr.) can affect the species richness and diversity of understory and insects. Twenty-one plots, ranging from pure larch stand to pure birch stand...

  3. DYNAMICS AND DISTINCTIONS IN CONCENTRATION OF THE BASIC PHOTOSYNTHETIC PIGMENTS OF LEAVES OF THE BIRCH GROWING IN IMPURE CONDITIONS

    Directory of Open Access Journals (Sweden)

    Михаил Эдуардович Баландайкин

    2014-09-01

    Full Text Available The complex of features of influence of external factors on frame of the basic photosynthetic pigments of a sheet plate of a birch is discussed. Besides, specificity of influence of the infectious pathological stress-factor – xylotroph basidial macromycet (facultative saprotroph a tinder fungus bevelled – on the content of a chlorophyll of phylum a, b, their sums, lipochromes, an interrelation of pigments in sheet plates of trees Betula pendula Roth. is shown.

  4. White Birch Trees as Resource Species of Russia : Their Distribution, Ecophysiological Features, Multiple Utilizations

    OpenAIRE

    Zyryanova, Olga A.; TERAZAWA, Minoru; KOIKE, TAKAYOSHI; Zyryanov, Vyacheslav I.

    2010-01-01

    Four birch tree species (Betula costata, B. pendula, B. platyphylla, B. pubescens) are traditionally important resource species in Russia. In the article, we discuss their spatial and ecophysiological features, biochemical constituents of the living tissues of the birches such as the wood, outer and inner bark, twigs, leaves, buds, roots. The exudation, tapping periods and sap productivity, exudated birch sap and derived birch tar are also reviewed. We show numerous useful wooden, medicinal, ...

  5. The effects of physical activity on the association between self-reported stress and episodic memory performance

    OpenAIRE

    Rajamäki, Suvi

    2010-01-01

    Recurrent stress has been found to impair brain structures essential to memory. The cognitive reserve model suggests that physical activity supplies protection against memory decline in neuropathologies. The purpose of the present study was to explore whether leisure physical activity modifies the predicted negative effect stress has on memory. A sub-sample derived from the Betula Study comprised 267 participants between 50 and 65 years. Memory was assessed by a SPT free recall and stress by ...

  6. Diabetes and cognitive functioning : The role of age and comorbidity

    OpenAIRE

    Nilsson, Erik

    2006-01-01

    This thesis deals with the influence of type 2 diabetes on cognitive function in adulthood and very old age. The effects of diabetes are studied both in populations free from dementia, and in a clinical Alzheimer's disease population. For Studies 1 & 11, a non-demented, non-depressed, sample of very old (>75 years of age) persons from the Kungsholmen Project in Stockholm, Sweden, was used. For Study Ill, data from the Betula prospective cohort study were employed. All select...

  7. Selection of trees for rubbing by red and roe deer in forest plantations

    OpenAIRE

    Ramos, Jaime; Bugalho, Miguel; Cortez, José Paulo; Iason, Glenn

    2006-01-01

    Antler rubbing is a form of behaviour by which deer may damage and ultimately induce mortality of trees. Understanding factors affecting selection of trees for rubbing may contribute to mitigation of negative effects of such behaviour in plantations or woodlands. We analysed characteristics of trees rubbed by red and roe deer along transects established in plantations of Pinus pinaster (Aiton), Pseudotsuga menziesii (Mirbel) Franco, Betula alba L. and Quercus robur L. in Northeast Portugal. T...

  8. Ground bryophyte diversity in secondary birch forests in western Sichuan, China

    OpenAIRE

    Xiaoli Yan; Weikai Bao

    2011-01-01

    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 ...

  9. Does tree seedling growth and survival require weeding of Himalayan balsam (Impatiens glandulifera)?

    OpenAIRE

    Ammer, Christian; Schall, Peter; Wördehoff, René; Lamatsch, Klaus; Bachmann, Martin

    2011-01-01

    The effect of Himalayan balsam (Impatiens glandulifera) on survival and growth of naturally regenerated silver birch (Betula pendula) and planted Norway spruce (Picea abies) and silver fir (Abies alba) seedlings was studied in a weeding experiment over 3 years. Three different treatments were applied: control, mowing, and hand weeding by pulling out the entire plant. There were no consistent treatment effects on height and diameter of the tree seedlings. The coverage of Rubus fruticosus had a...

  10. Firewood properties of some Indian mountain tree and shrub species

    Energy Technology Data Exchange (ETDEWEB)

    Bhatt, B.P.; Tomar, J.M.S. [ICAR Research Complex for NEH Region, Agroforestry Div., Meghalaya (India)

    2002-10-01

    Quantitative analysis of 26 indigenous mountain fuelwood species of North-Eastern Himalayan region was carried out to identify trees with potential for fuelwood production. A fuelwood value index (FYI) was defined as calorific value x density/ash content. Betula nitida, Machilus bombycina, Itea macrophylla, Cryptomeria japonica, Gmelina arborea, Simingtonia populnea, Macaranga denticulata and Schima wallichii were shown to have promising firewood production. (Author)

  11. Effect of Root Moisture Content and Diameter on Root Tensile Properties

    OpenAIRE

    Yuanjun Yang; Lihua Chen; Ning Li; Qiufen Zhang

    2016-01-01

    The stabilization of slopes by vegetation has been a topical issue for many years. Root mechanical characteristics significantly influence soil reinforcement; therefore it is necessary to research into the indicators of root tensile properties. In this study, we explored the influence of root moisture content on tensile resistance and strength with different root diameters and for different tree species. Betula platyphylla, Quercus mongolica, Pinus tabulaeformis, and Larix gmelinii, the most ...

  12. Perceived chronic stress, health and cognition

    OpenAIRE

    Öhman, Lena

    2006-01-01

    The aim of this licentiate thesis was to examine consequences of chronic stress for stressrelated diseases and to investigate the chronic stress – cognition relationship. In the first study data covering ten years was used from the Betula Prospective Cohort Study (Nilsson et al., 1997). Based on the ratings on a stress scale, matched samples between 40 and 65 years of age were divided into a high and low stress group. The reported incidence of cardiovascular, diabetes, psychiatric, tumor, and...

  13. Birch pollen allergy: molecular characterization and hypoallergenic products

    OpenAIRE

    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 allergen is Bet ν 1, which is the conventional allergen name for the birch pollen proteins of a large group of proteins otherwise known as PR-10 proteins. Individuals that suffer from birch pollen al...

  14. Root system traits of Norway spruce, Scots pine, and silver birch in mixed boreal forests: an analysis of root architecture, morphology, and anatomy

    OpenAIRE

    Kalliokoski, Tuomo

    2011-01-01

    The aim of this thesis was to unravel the functional-structural characteristics of root systems of Betula pendula Roth., Picea abies (L.) Karst., and Pinus sylvestris L. in mixed boreal forest stands differing in their developmental stage and site fertility. The root systems of these species had similar structural regularities: horizontally-oriented shallow roots defined the horizontal area of influence, and within this area, each species placed fine roots in the uppermost soil layers, w...

  15. Betulin Complex in γ-Cyclodextrin Derivatives: Properties and Antineoplasic Activities in In Vitro and In Vivo Tumor Models

    OpenAIRE

    Florina Bojin; Rita Ambrus; Gerhard Wenz; Hai Ming Wang; Corina Danciu; Cristina Dehelean; Codruta Şoica; Mariana Anghel

    2012-01-01

    Given the present high incidence of melanoma and skin cancer, interest in potential drugs of plant origin has increased significantly. Pentacyclic lupane-type triterpenes are widely distributed in plants, offering numerous pharmacological benefits. Betulin is an important compound in the bark of Betula pendula Roth and has important therapeutic properties, including antitumor activities. Its biological effect is limited by its poor water solubility, which can be improved by cyclodextrin compl...

  16. Spatial distribution of forests and woodlands in Iceland in accordance with the CORINE land cover classification

    OpenAIRE

    Björn Traustason 1971; Arnór Snorrason 1960

    2014-01-01

    This paper presents a united geographical database for all known forest and woodland areas in Iceland, both natural and planted. This first edition of the database follows forest and woodland classifications used in the European CORINE land cover program. According to the database, the total area of forests and woodlands in Iceland was estimated as being 156,800 ha, divided into natural downy birch (Betula pubescens) woodland (115,400 ha) and forest plantations (41,400 ha). The natural birch ...

  17. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Speciation of Mg, Mn and Zn in extracts of medicinal plants

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Guenther [Institute of Spectrochemistry and Applied Spectroscopy, Bunsen-Kirchhoff-Str. 11, 44139, Dortmund (Germany); Konieczynski, Pawel [Department of Analytical Chemistry, Medical University of Gdansk, ul. Hallera 107, 80-416, Gdansk (Poland)

    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 (<5000 Da). Further characterisation of the low molecular weight fraction is done by using size exclusion chromatography and different detectors, namely element specific AAS detection, diode array UV-VIS detection and electrochemical detection. The similarities and differences of the plant extracts are well reflected by the respective chromatograms, and typical plant constituents can be identified by their spectral and electrochemical properties (e.g. flavonoids in Betula). Mg and Mn species are selectively detected by AAS in closely neighbouring chromatographic regions for all five samples. However, there are significant differences between the samples investigated. In all cases a good correlation exists between detection of these metals (Mg, Mn) and pulsed amperometric detection (PAD), which is selective for carbohydrates. The respective molecular weight of carbohydrate species is in the range of approximately 300-600 Da. The distribution of zinc species (detectable only in the Betula extract) is totally different from that of Mg and Mn species. For zinc, many more species are detected, and there is no correlation to carbohydrates; instead (poly)phenols are involved in zinc complexation. (orig.)

  19. БИОХИМИЧЕСКИЕ ОСОБЕННОСТИ КОНСТИТУТИВНОЙ РЕЗИСТЕНТНОСТИ БЕРЕЗЫ ПОВИСЛОЙ (BETULA PENDULA ROTH. ) К ПОВРЕЖДЕНИЮ НАСЕКОМЫМИ-ФИЛЛОФАГАМИ В УСЛОВИЯХ АНТРОПОГЕННОГО ВОЗДЕЙСТВИЯ

    OpenAIRE

    Колтунов, Е. В.; ЯКОВЛЕВА М.И.

    2014-01-01

    Проведено изучение биохимических факторов природной (конститутивной) энтоморезистентности из листьев березы повислой из затухших очагов непарного шелкопряда и за их границами. Хроматографический анализ (ВЭЖХ) выявил 51-54 фенольных соединения. В образцах за границами очагов выявлено преобладание фенольных соединений с заметным возрастанием содержания в пике (38,9%), по сравнению с контролем (образцы из очагов). В их составе флавоноиды, фенолгликозиды, фенолкарбоновые кислоты. В составе фенолг...

  20. ВЛИЯНИЕ ТЕХНОГЕННОГО ЗАГРЯЗНЕНИЯ НА СОДЕРЖАНИЕ ФЕНОЛЬНЫХ СОЕДИНЕНИЙ В ЛИСТЬЯХ БЕРЕЗЫ ПОВИСЛОЙ (BETULA PENDULA ROTH.) В УСЛОВИЯХ УРБАНИЗАЦИИ

    OpenAIRE

    ШАВНИН С.А.; Колтунов, Е. В.; ЯКОВЛЕВА М.И.

    2014-01-01

    Хроматографический анализ фенольных соединений из листьев березы повислой в условиях урбанизации на разном расстоянии от городской автомагистрали выявил 51-54 соединения. Из общего количества идентифицировано 15 фенольных соединений (флавоноиды, фенолкарбоновые и гидроксикоричные кислоты). Попарный сравнительный анализ образцов из листьев деревьев вблизи автомагистрали показал значительное преобладание фракций со снижением содержания соединений (68,18%). Возрастание содержания фенольных соеди...

  1. Soil Warming and Fertilization Effects on Growth Ring Widths of Arctic Shrubs - Application of a Novel Dendroecological Approach.

    Science.gov (United States)

    Iturrate Garcia, M.; Heijmans, M.; Schweingruber, F. H.; Niklaus, P. A.; Schaepman-Strub, G.

    2015-12-01

    Climate warming is suggested as the main driver of shrub expansion in arctic tundra regions. Shrub expansion may have consequences on biodiversity and climate, especially through its feedbacks with the energy budget. A better understanding of shrub expansion mechanisms, including growth rate patterns and stem anatomy changes, and their sensitivity to climate is needed in order to quantify related feedbacks. We present a novel dendroecological approach to determine the response of three arctic shrub species to increased soil temperature and nutrients. A full factorial block-design experiment was run for four years with a total of thirty plots. Six individuals of each species were sampled from each plot to test for treatment effects on growth rate and stem anatomy. We compared the ring width of the four years of experiment with the one of the four previous years. The preliminary results for Betula nana and Salix pulchra suggest a significant effect of the treatments on the growth ring width. The response is stronger in Salix pulchra than in Betula nana individuals. And, while Salix pulchra is more sensitive to the combined soil warming and fertilization treatment, Betula nana is to the fertilization treatment. We could not observe an effect of treatment on the stem anatomy, likely because bark thickness co-varies with age. We found significant positive correlations of cork, cortex and phloem thickness with xylem thickness (used as a proxy of age), and a significant difference in stem anatomy between species. The results suggest species-specific growth sensitivity to soil warming and nutrient enhancement. The use of experimental dendroecology by manipulating environmental conditions according to future climate scenarios and testing effects on shrub anatomy and annual growth will increase our understanding on shrub expansion mechanisms. Ongoing plant trait analysis and consecutive application in a 3D radiative transfer model will allow to quantify the feedback of

  2. Vegetation response to climate forcing during the last glacial maximum and deglaciation in the East Carpathians: attenuated response to maximum cooling and increased biomass burning

    Directory of Open Access Journals (Sweden)

    Eniko M. MAGYARI

    2014-11-01

    Full Text Available The Carpathian Mountains were one of the main mountain reserves of the boreal and cool temperate flora during the Last Glacial Maximum (LGM in East-Central Europe. Previous studies demonstrated late glacial vegetation dynamics in this area; however, our knowledge on the LGM vegetation composition is limited due to the scarcity of suitable sedimentary archives. Here we present a new record of vegetation, fire and lacustrine sedimentation from the youngest volcanic crater of the Carpathians (Lake St Anne, Lacul Sfânta Ana, Szent-Anna-tó to examine environmental change in this region during the LGM and the subsequent deglaciation. Our record indicates the persistence of boreal forest steppe vegetation (Pinus sylvestris, Pinus mugo, Pinus cembra, Betula, Salix, Populus, Picea abies in the foreland and low mountain zone of the East Carpathians and Juniperus shrubland at higher elevation. We demonstrate attenuated response of the regional vegetation to maximum global cooling. Between ~22,870 and 19,150 cal yr BP we find increased regional biomass burning that is antagonistic with the global trend. Increased regional fire activity suggests extreme continentality likely with relatively warm and dry summers. We also demonstratexerophytic steppe expansion directly after the LGM, from ~19,150 cal yr BP, and regional increase in boreal woodland cover with Pinus and Betula from 16,300 cal yr BP. Plant macrofossils indicate local (950 m a.s.l. establishment of Betula nana and B. pubescens at 15,150 cal yr BP, Pinus sylvestris at 14,700 cal yr BP and Larix decidua at 12,870 cal yr BP. Pollen data furthermore hints at the regional presence of some temperate deciduous trees during the LGM (Fagus sylvatica, Carpinus betulus, Corylus avellana, Fraxinus excelsior, Ulmus. We also present pollen based quantitative climate reconstruction from this site and discuss its connection with other climate reconstructions and climate modeling results. 

  3. The phenological phases of flowering and pollen seasons of spring flowering tree taxa against a background of meteorological conditions in Kraków, Poland

    Directory of Open Access Journals (Sweden)

    Danuta Stępalska

    2016-06-01

    Full Text Available The aim of the study was to compare phenological observations of pollen seasons of selected early spring trees. Special attention was paid to meteorological conditions which favored or did not favor tree flowering and pollen release. For this reason, we used phenological observation, pollen counts, and meteorological data in five sites in the center of Kraków in the period 2009–2011. Phenological phases (5 of four tree species: Alnus glutinosa, Alnus incana, Corylus avellana, and Betula pendula, were analyzed. It was found that in case of A. glutinosa the pollen season often preceded the flowering period, while for A. incana those two phenomena were more correlated. As regards Corylus avellana, the beginning of the pollen season and phenological phases was simultaneous. However, pollen grains occurred in the air longer, even by a dozen or so days. The phenological phases and pollen seasons of Alnus and Corylus were dependent on meteorological conditions. To give the definition of the relationship between pollen concentration and weather conditions, Spearman rank correlation analysis was applied. High Alnus and Corylus pollen concentrations were found on sunny days with a maximum temperature over 10°C and no precipitation, and when the snow cover was gone. In case of Betula, the phenological phases of the full pollination period usually coincided with the periods of high pollen concentrations. However, Betula pollen sometimes appears earlier and stays in the air longer than the flowering period of local trees in the nearest vicinity. This situation indicates long-distance transport or secondary deposition.

  4. Twenty-two years of warming, fertilisation and shading of subarctic heath shrubs promote secondary growth and plasticity but not primary growth.

    Directory of Open Access Journals (Sweden)

    Matteo Campioli

    Full Text Available Most manipulation experiments simulating global change in tundra were short-term or did not measure plant growth directly. Here, we assessed the growth of three shrubs (Cassiope tetragona, Empetrum hermaphroditum and Betula nana at a subarctic heath in Abisko (Northern Sweden after 22 years of warming (passive greenhouses, fertilisation (nutrients addition and shading (hessian fabric, and compare this to observations from the first decade of treatment. We assessed the growth rate of current-year leaves and apical stem (primary growth and cambial growth (secondary growth, and integrated growth rates with morphological measurements and species coverage. Primary- and total growth of Cassiope and Empetrum were unaffected by manipulations, whereas growth was substantially reduced under fertilisation and shading (but not warming for Betula. Overall, shrub height and length tended to increase under fertilisation and warming, whereas branching increased mostly in shaded Cassiope. Morphological changes were coupled to increased secondary growth under fertilisation. The species coverage showed a remarkable increase in graminoids in fertilised plots. Shrub response to fertilisation was positive in the short-term but changed over time, likely because of an increased competition with graminoids. More erected postures and large, canopies (requiring enhanced secondary growth for stem reinforcement likely compensated for the increased light competition in Empetrum and Cassiope but did not avoid growth reduction in the shade intolerant Betula. The impact of warming and shading on shrub growth was more conservative. The lack of growth enhancement under warming suggests the absence of long-term acclimation for processes limiting biomass production. The lack of negative effects of shading on Cassiope was linked to morphological changes increasing the photosynthetic surface. Overall, tundra shrubs showed developmental plasticity over the longer term. However, such

  5. Stature of Sub-arctic Birch in Relation to Growth Rate, Lifespan and Tree Form

    OpenAIRE

    JÓNSSON, THORBERGUR HJALTI

    2004-01-01

    • Background and Aims Sub-arctic mountain birch Betula pubescens var. pumila communities in the North Atlantic region are of variable stature, ranging from prostrate scrubs to forests with trees up to 12 m high. Four hypotheses were tested, relating growth and population characteristics of sub-arctic birch woodland and scrub to tree stature; i.e. the variable stature of birch woods is due to differences in (1) the mean growth rate; (2) the age-related patterns of growth rate; (3) the life exp...

  6. Arboristični vidiki snegoloma v mestni občini Ljubljana v zimi 1999:

    OpenAIRE

    Marion, Lena; Oven, Primož; Torelli, Niko

    2005-01-01

    As a result of heavy snow in February 1999, trees were damaged in the City of Ljubljana, Slovenia. Of the investigated 624 trees, 195 (31%) were damaged by snow. On average, 1.7 branch and top per tree were broken. Snow damaged 17 tree species, affecting particularly Aesculus hippocastanum L. and, to a lesser extent, Betula pendula ROTH. and Salix x sepulcralis SIMONK. Decay was the most frequent defect at the failure location and was often associated withincluded bark and vicinity of old mec...

  7. Analysis of trees planted in vicinity of hospitals in Ljubljana as a source of pollen

    OpenAIRE

    Kofol Seliger, Andreja; Pirnat, Janez

    2010-01-01

    The paper analyses woody plants growing in the vicinity of hospital buildings situated along Zalog Road, Korytko Street, Šlajmar Street, Bohorič Street and Njegoš Street in Ljubljana, Slovenia. Woody plants are an immediate potential source of allergenic pollen, affecting all park users such as patients, visitors and hospital employees. The most allergenic tree species in the park was found to be birch (Betula pendula Roth.), which accounts for 6.8% of all registered trees. The low allergenic...

  8. Air pollution and the respiration of certain tree species

    Energy Technology Data Exchange (ETDEWEB)

    Makedonska, T.; Slavova, V.

    1973-01-01

    These studies are conducted to compare the effects of air pollution on horse chestnut (Aesculus hippocastanum L.), London plane (Platanus acerifolia Milld.) ash-leaved maple (Acer negundo L.) and European birch (Betula alba L.). With increasing concentrations of air pollution these species react by increasing the intensity of respiration, as in separate cases the increase reaches up to 40%. Most sensitive to air pollution is the horse chestnut, followed by birch and ash-leaved maple; least sensitive is London plane. With respect to gas resistance birch and ash-leaved maple rank close to the horse chestnut but are more resistant than the horse chestnut and less sensitive than London plane.

  9. rboricultural aspects of snow-damage in the citz of Ljubljana in the winter 1999

    OpenAIRE

    Marion, Leon; Torelli, Niko; Oven, Primož

    2005-01-01

    As a result of heavy snow in February 1999, trees were damaged in the City of Ljubljana, Slovenia. Of the investigated 624 trees, 195 (31%) were damaged by snow. On average, 1.7 branch and top per tree were broken. Snow damaged 17 tree species, affecting particularly Aesculus hippocastanum L. and, to a lesser extent, Betula pendula ROTH. and Salix x sepulcralis SIMONK. Decay was the most frequent defect at the failure location and was often associated withincluded bark and vicinity of old mec...

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

    DEFF Research Database (Denmark)

    Bødtger, Uffe; Poulsen, L K; Jacobi, H H;

    2002-01-01

    BACKGROUND: 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....... METHODS: Thirty-five patients with severe rhinoconjunctivitis (hay fever) to birch pollen were allocated to double-blinded clustered IT with a depot birch pollen extract (Betula verrucosa) or placebo injections. Seven patients in each group had concomitant self-reported seasonal asthma. Treatment...... antihistamines (P effects at the same level as placebo...

  11. Environmentally friendly utilization of biomass

    OpenAIRE

    Grimm, Alejandro

    2007-01-01

    The thesis deals with various ways of utilization of biomass. Chapter 1 compares three biomass types: birch wood Betula sp., marine brown alga Fucus vesiculosus, and terrestrial moss Pleurozium schreberi, as precursors for preparation of biosorbents for removal of copper ions from diluted water solutions. Small sample doses (0.5 g/100ml) of the biosorbents prepared from alga and moss enabled more than 90 % removal of Cu (II) ions from diluted water solutions (5-20 mg/l). The sample from birch...

  12. AcEST: DK948735 [AcEST

    Lifescience Database Archive (English)

    Full Text Available Sbjct: 181 VVEPYNSVLSTHSLLEHTD 199 >tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wilsonii GN=TUA1 PE=2 SV=1...E Alpha tubulin OS=Betula verrucosa PE=2 SV=1 369 e-101 tr|A9QVH4|A9QVH4_9CONI Alpha tubulin OS=Picea wils...onii GN=TUA1 P... 369 e-101 tr|A9PL19|A9PL19_GOSHI Alpha-tubulin OS=Gossypium hirsu

  13. Contribución al conocimiento de agaricales y russulales de los Pirineos aragoneses (Valles de Ordesa y Pineta-Huesca).

    OpenAIRE

    CASTRO CERCEDA, M.L., FREIRE, L.

    1991-01-01

    En este trabajo enumeramos unas 40 especies de macromicetos,   pertenecientes a los órdenes Agaricales y Russulales, que fueron   encontrados por los autores, durante el otoño de 1989, en la II   Campaña de Microflora Ibérica. Las especies han sido recolectadas preferentemente en bosques   mixtos de hayas (Fagus sylvativa) y abetos (Abies alba) con   extraordinario sotobosque de boj (Buxus sempervirens), pero   también fueron visitados abedulares (Betula sp.) y prados. ...

  14. Biomass functions for young scots pine-dominated forest

    Energy Technology Data Exchange (ETDEWEB)

    Ahnlund Ulvcrona, K. (Vindeln Experimental Forests, Svartberet Research Station, Swedish Univ. of Agricultural Science, Vindeln (Sweden)), e-mail: Kristina.ulvcrona@esf.slu.se; Nilsson, U. (Southern Swedish Forest Research centre, Swedish Univ. of Agricultural Science, Alnarp (Sweden)); Lundmark, T. (Forest Ecology and Management, Swedish Univ. of Agricultural Science, Umeaa (Sweden))

    2010-07-15

    The aim of this study was to develop predictive biomass functions for young stands of Scots pine-dominated forests in northern Sweden. Above ground biomass was destructively sampled, and biomass functions for all tree fractions (e.g. stem including bark, branch and foliage) were developed, based on independent variables. Functions to estimate dry weight of the whole tree were also developed. No significant regressions could be found for the dead branch fraction. DBH for sampled trees in this study was in the range of 11 - 136 mm (Pinus sylvestris), 10 - 121 mm (Picea abies L. Karst) and 9 - 113 mm (Betula spp.)

  15. The biochemical and histoanatomical response of some woody species to anthropic impact in Suceava County, Romania

    OpenAIRE

    Elena CIORNEA; Irina BOZ; IONEL, ELENA; COJOCARU, SABINA IOANA; DUMITRU, Gabriela

    2015-01-01

    The use of extractive mining technologies in various areas of Suceava, Romania (C?limani Mountains - sulfur, Tarni?a-Ostra - copper and barite, and Crucea-Botuşana - uranium) has resulted in the accumulation of surplus chemicals with direct action on the ecosystem. The aim of this study was to analyze the possible damage on some woody species (Picea abies L., Populus tremulaL., Salix alba L., Betula verrucosa Ehrh.,and Larix decidua Mill.) and their adaptive and phytoremediation capacity thro...

  16. Inhibition of the growth of Alexandrium tamarense by algicidal substances in Chinese fir (Cunninghamia lanceolata).

    Science.gov (United States)

    Yang, Wei-Dong; Liu, Jie-Sheng; Li, Hong-Ye; Zhang, Xin-Lian; Qi, Yu-Zao

    2009-10-01

    The wood sawdust from Chinese fir (Cunninghamia lanceolata) exhibited stronger inhibition on the growth of Alexandrium tamarense than those from alder (Alnus cremastogyne), pine (Pinus massoniana), birch (Betula alnoides) and sapele (Entandrophragma cylindricum). The water extract, acetone-water extract and essential oil from fir sawdust were all shown to inhibit the growth of A. tamarense. The inhibition of fir essential oil was the strongest among all the above wood sources while the half effective concentration was only 0.65 mg/L. These results suggested that the fir essential oil may play an important role in the algicidal effect of Chinese fir. PMID:19634014

  17. PURIFICATION OF HARDWOOD-DERIVED AUTOHYDROLYSATES

    OpenAIRE

    Joni Tapani Lehto,; Raimo Juhani Alén

    2012-01-01

    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-(hydroxymethyl)furfural) could be removed, whereas in th...

  18. Effect of Tree Species and Mycorrhizal Colonization on the Archaeal Population of Boreal Forest Rhizospheres▿

    OpenAIRE

    Bomberg, Malin; Timonen, Sari

    2008-01-01

    Group 1.1c Crenarchaeota are the predominating archaeal group in acidic boreal forest soils. In this study, we show that the detection frequency of 1.1c crenarchaeotal 16S rRNA genes in the rhizospheres of the boreal forest trees increased following colonization by the ectomycorrhizal fungus Paxillus involutus. This effect was very clear in the fine roots of Pinus sylvestris, Picea abies, and Betula pendula, the most common forest trees in Finland. The nonmycorrhizal fine roots had a clearly ...

  19. Flora vascular acompañante en masas de monte bajo de castaño en Asturias

    OpenAIRE

    García, Andrés; Díaz-, T.; Majada, Juan; Ciordia, Marta

    2014-01-01

    En Asturias, las zonas forestales ocupan un total de 762.329 hectáreas, es decir, el 72,2% de la superficie del Principado es monte. De éstas, 453.700 hectáreas son arboladas, siendo los bosques de caducifolios (hoja caduca) los más abundantes y que representan en torno al 20% de la superficie asturiana. En estos bosques encontramos, por ejemplo, especies arbóreas como el roble (Quercus spp.), el abedul (Betula celtiberica Rothm. & Vasc.) o el haya (Fagus sylv...

  20. Biomass distribution patterns of ecotones between forest and swamp in Changbai Mountain

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper studied the biomass distribution patterns of Larix olgensis/swamp ecotones and Betula platyphlla/swamp ecotones in Changbai Mountain so as to provide theory foundation for the management of these nature resources, by setting up sample belts, investigating initial data along the environmental gradients change, and establishing regression models. By means of regression models, the biomass of communities, layers, tree species and organs was calculated. In this system, it was found that the community biomass increased gradually along the environmental gradients change from swamp to forest in Changbai Mountain. Furthermore, the ecotoneal biomass distributed mainly over tree layer. The tree biomass distributed mainly in two or three dominate tree species.

  1. Fuelwood characteristics of selected indigenous tree species from central India

    Energy Technology Data Exchange (ETDEWEB)

    Jain, R.K.; Singh, B. [National Botanical Research Institute, Lucknow (India)

    1999-06-01

    Thirty tree species indigenously growing in their natural habitat in subtropical forest of central India were collected and fuelwood properties viz, moisture, silica, ash, density, carbon, nitrogen, volatile matter, calorific value and fuel value index (FVI) calculated to screen desirable species for potential production of fuelwood in these areas. The present study revealed that Acer oblongum, Betula alonoides, Grevillea robusta, Limonia acidissima, Lyonia ovalifolia, Madhuca indica, Melia azedarch, Morinda tinctoria, Myrica sapida, Prunus cornuta, Pyrus pashia, Quercus langinosa, Rhamnus triqueter and Stereospermum xylocarpum possess excellent fuelwood qualities. (Author)

  2. Preliminary report on distribution of Heterobasidion annosum intersterility groups in Poland

    Directory of Open Access Journals (Sweden)

    Piotr Łakomy

    2014-08-01

    Full Text Available The study material consists of 165 H. annosum isolates from 25 different localities. Host species was Pinus sylvestris, Picea abies, Betula pendula, Abies alba, Lnrix decidua, Pinus strobus, Prunus serotina, Quercus rubra. Most of the H. annosum isolates belonged to the P group. This group was most common on pine and birch. The S group infected Norway spruce and European fir. The F group was recorded only in the south of Poland. Only three localities, where this intersterility group was present, were found in Poland.

  3. AGING AND DECISION MAKING AS MEASURED BY THE SWEDISH VERSION OF THE ADMC BATTERY

    OpenAIRE

    jaafar hussein, amez

    2013-01-01

    The aim of this study was to examine age-related differences in decision-making competence. The study is a part of the ongoing Betula project (Nilsson et al., 1997; 2004), and the data included test results from (N, 364) corresponding to the questionnaires with complete responses (>80%) to the items addressed. The Swedish version of the Adult Decision-Making Competence (A-DMC) battery was used. An exploratory factor analysis of the A-DMC data yielded a two-component solution: The A-DMC tas...

  4. Few long-term effects of simulated climate change on volatile organic compound emissions and leaf chemistry of three subarctic dwarf shrubs

    DEFF Research Database (Denmark)

    Rinnan, Riikka; Rinnan, Åsmund; Faubert, Patrick;

    2011-01-01

    led to other chemical changes detected in the near-infrared reflectance spectra of the leaves. Nevertheless, there were no significant differences in the BVOC emissions per unit leaf mass measured by the dynamic enclosure method and gas chromatography-mass spectrometry. Annual additions of NPK...... Betula nana L. had significant emissions of various reactive BVOCs, including monoterpenes and sesquiterpenes. The evergreen Cassiope tetragona (L.) D. Don emitted high amounts of mono- and sesquiterpenes. Due to chance, the temperature in the warming treatment (employing open-top plastic tents...

  5. Pollen record and environmental evolution of Caotanhu wetland in Xinjiang since 4550 cal. a BP

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yun; KONG ZhaoChen; NI Jian; YAN Shun; YANG ZhenJing

    2008-01-01

    This paper presents a multi-proxy reconstruction of the climate change in Caotanhu wetland using pollen, phytolith and charcoal records, and the data of loss of ignition (LOI), grain size analysis, and susceptibility. Results reveal that between 4550 and 2500 cal. a BP, a dry climatic condition was not favorable for the accumulation of peat. Since 2500 cal. a BP, the climate became humid and the wetland developed with abundant freshwater aquatic plants, which contributed to peat accumulation. Never-theless, alternate periods of rain and dry climate occurred during that period. Between 2500 and 1810 cal. a BP (550 BC-140 AD), the climate was more humid than at present. A lot of emerged plants, such as Phragmites, Typha and Sparganium, and freshwater green algae grew in the wetland which was sur-rounded by desert-steppe vegetation composed mainly of Chenopodiaceae, Arternisia, Compositae and Thalictrum. However, from 1810 to 1160 cal. a BP (140-790 AD), the water level started to decrease and hydrophyte species reduced greatly, but some Phragmites still grew in the wetland and around it was desert vegetation with high proportion of Chenopodiaceae and Artemisia. Then from 1160 to 650 a BP (790-1300 AD), it entered a period of desert-steppe with abundant mesic and xerophytic plants. And a lot of aquatic plants prevailed in the wetland. Here, what is noticeable is that percentages of arboreal pollen, consisting mainly of Betula and Picea, increased greatly and reached a maximal value of 27.2%, in which, Betula percentages rose to 23.2%. Hence, it is reasonable to conclude that Betula grew in the highland of the wetland, or Picea timberline shifted downward resulting in the increase of percentages of Betula and Picea pollen, which were transported into the wetland by flood or wind. But since 650 cal. a BP, desert vegetation prevailed around the wetland again with dominant Chenopodiaceae and Ar-temisia, and the climate was similar to modern one. Despite some aquatic

  6. Comparative analysis of species-based specificity in Sz90 and Cs137 accumulation demonstrated by ligneous plant forest communities

    International Nuclear Information System (INIS)

    Field-proven study of Sr90 and Cs137 absorption activity demonstrated by pinus silvestris l., piceae abies (l) roth, quercus rubra l., acer platanoides l., betula pendula roth., tilia cordata mill. under identical habitat conditions. The above plants were examined after 5-year growth period on radionuclide-contaminated soil. To a great extent, such parameters as radionuclide accumulation in experimental plants and accumulation activity were determined by the plants' bio-ecological properties. Differences relevant to these parameters could reach 15-fold value

  7. Retranslocation of foliar nutrients of deciduous tree seedlings in different soil condition under free-air O3 enrichment

    OpenAIRE

    Shi C; Eguchi N; Meng F; Watanabe T.; Satoh F; Koike T.

    2016-01-01

    Retranslocation is the amount of an element that is depleted from old plant components and is provided for new growth. Leaf senescence is usually accelerated at elevated O3 (eO3), and leaf shedding is influenced by soil nutrient availability (and acidification). In this study, we focused on the net retranslocation and allocation dynamics of foliar nutrients (N, P, Mg, K, Ca, Mn, Fe and Al) to investigate the effect of eO3 on birch (Betula platyphylla var. japonica), oak (Quercus mongolica var...

  8. Application of calibration standardization method to the analysis of diuretic pharmaceutical herbs

    International Nuclear Information System (INIS)

    Calibration standardization of X-ray fluorescence method was carried out for the determination of the anorganic contents in diuretic herbs as called Folia Betulae, Stylus Maydis, Flores Verbasci, Equisetum Arvense and Flos Helichrysi, growing in Turkey. These herbs are widely used in pharmacy and public health for kidney disease therapy. Herb samples were steeped in the water and mixed through the pure cellulose, then pelletized in the intermediate thickness. An annular source of 109Cd (3.7 MBq) was used for excitation of fluorescent K lines of elements lying between potassium and zirconium. Toxic elements in considerable amounts were not found. (author)

  9. Invertase and urease activities in the reclamated land of the western Donets basin

    Directory of Open Access Journals (Sweden)

    O. M. Vasilyuk

    2009-09-01

    Full Text Available The research data on activities of invertase (as one of the most important enzymes for soil biological activity, humus content and soil fertility and urease (as an enzyme of nitrogen metabolism, which transforms the inorganic nitrogen compounds into the organic ones in soils of artificial afforestations of Robinia pseudoacacia L., Betula pendula Rosh., Quercus robur L. and Acer platanoides L. at the reclamated lands of the Western Donets Basin are presented. The seasonal dynamics of soil activity subject to the type of biogeocenosis is shown.

  10. Brood parasitism on the Yellow-rumped Flycatcher (Ficedula zanthopygia) by the Oriental Cuckoo (Cuculus optatus)in an artificial nestbox in Beijing%北京小龙门地区中杜鹃寄生人工巢箱中的白眉姬鹟

    Institute of Scientific and Technical Information of China (English)

    邓文洪

    2013-01-01

    2005年在北京小龙门地区发现一对白眉姬鹟(Ficedula zanthopygia)在悬挂于一棵白桦(Betula platyphylla)树上的人工巢箱中繁殖,巢箱内共有5枚卵,其中1枚卵显著大于其他4枚,经过鉴定确认为中杜鹃(Cuculus optatus)的卵.这是首次记录到中杜鹃在人工巢箱中对白眉姬鹟的寄生现象.

  11. Climate versus in-lake processes as controls on the development of community structure in a low-arctic lake (South-West Greenland)

    DEFF Research Database (Denmark)

    Anderson, N. John; Brodersen, Klaus Peter; Ryves, David B.;

    2008-01-01

    variables (Holocene temperature, an isotope-inferred cooling period, and immigration of Betula nana into the catchment) were explored using redundancy analysis (RDA) independent of time. The main ecological trajectories in the lake biota were captured by ordination first axis sample scores (18-32% variance......-lived cooling period (identified by altered stable isotopes) early in the development of the lake when all proxies changed rapidly, although only chironomids had a unique component (8% in a partial-RDA) explained by the cooling event. Holocene climate explained less variance than either catchment changes...

  12. Genotypic variation in yellow autumn leaf colours explains aphid load in silver birch.

    Science.gov (United States)

    Sinkkonen, Aki; Somerkoski, Eeva; Paaso, Ulla; Holopainen, Jarmo K; Rousi, Matti; Mikola, Juha

    2012-07-01

    • It has been suggested that autumn-migrating insects drive the evolution of autumn leaf colours. However, evidence of genetic variation in autumn leaf colours in natural tree populations and the link between the genetic variation and herbivore abundances has been lacking. • Here, we measured the size of the whole aphid community and the development of green-yellow leaf colours in six replicate trees of 19 silver birch (Betula pendula) genotypes at the beginning, in the middle and at the end of autumn colouration. We also calculated the difference between green leaf and leaf litter nitrogen (N) and estimated the changes in phloem sap N loading. • Autumn leaf colouration had significant genetic variation. During the last survey, genotypes that expressed the strongest leaf reflectance 2-4 wk earlier had an abundance of egg-laying Euceraphis betulae females. Surprisingly, the aphid community size during the first surveys explained N loss by the litter of different birch genotypes. • Our results are the first evidence at the tree intrapopulation genotypic level that autumn-migrating pests have the potential to drive the evolution of autumn leaf colours. They also stress the importance of recognizing the role of late-season tree-insect interactions in the evolution of herbivory resistance. PMID:22548444

  13. Effects of Flavonoid-rich Plant Extracts on In vitro Ruminal Methanogenesis, Microbial Populations and Fermentation Characteristics.

    Science.gov (United States)

    Kim, Eun T; Guan, Le Luo; Lee, Shin J; Lee, Sang M; Lee, Sang S; Lee, Il D; Lee, Su K; Lee, Sung S

    2015-04-01

    The objective of this study was to evaluate the in vitro effects of flavonoid-rich plant extracts (PE) on ruminal fermentation characteristics and methane emission by studying their effectiveness for methanogenesis in the rumen. A fistulated Holstein cow was used as a donor of rumen fluid. The PE (Punica granatum, Betula schmidtii, Ginkgo biloba, Camellia japonica, and Cudrania tricuspidata) known to have high concentrations of flavonoid were added to an in vitro fermentation incubated with rumen fluid. Total gas production and microbial growth with all PE was higher than that of the control at 24 h incubation, while the methane emission was significantly lower (pPunica, Betula, Ginkgo, Camellia, and Cudrania treatments, respectively. Ciliate populations were reduced by more than 60% in flavonoid-rich PE treatments. The Fibrobacter succinogenes diversity in all added flavonoid-rich PE was shown to increase, while the Ruminoccocus albus and R. flavefaciens populations in all PE decreased as compared with the control. In particular, the F. succinogenes community with the addition of Birch extract increased to a greater extent than that of others. In conclusion, the results of this study showed that flavonoid-rich PE decreased ruminal methane emission without adversely affecting ruminal fermentation characteristics in vitro in 24 h incubation time, suggesting that the flavonoid-rich PE have potential possibility as bio-active regulator for ruminants. PMID:25656200

  14. Holocene Vegetation Succession and Response to Climate Change on the South Bank of the Heilongjiang-Amur River, Mohe County, Northeast China

    Directory of Open Access Journals (Sweden)

    Chao Zhao

    2016-01-01

    Full Text Available Pollen samples from peat sediments on the south bank of the Heilongjiang River in northern Northeast China (NE China were analyzed to reconstruct the historical response of vegetation to climate change since 7800 cal yr BP. Vegetation was found to have experienced five successions from cold-temperate mixed coniferous and broadleaved forest to forest-steppe, steppe-woodland, steppe, and finally meadow-woodland. From 7800 to 7300 cal yr BP, the study area was warmer than present, and Betula, Larix, and Picea-dominated mixed coniferous and broadleaved forests thrived. Two cooling events at 7300 cal yr BP and 4500 cal yr BP led to a decrease in Betula and other broadleaved forests, whereas herbs of Poaceae expanded, leading to forest-steppe and then steppe-woodland environments. After 2500 cal yr BP, reduced temperatures and a decrease in evaporation rates are likely to have resulted in permafrost expansion and surface ponding, with meadow and isolated coniferous forests developing a resistance to the cold-wet environment. The Holocene warm period in NE China (7800–7300 cal yr BP could have resulted in a strengthening of precipitation in northernmost NE China and encouraged the development of broadleaved forests.

  15. Pollen calendar of Lublin, 1995-2000

    Directory of Open Access Journals (Sweden)

    Krystyna Piotrowska

    2012-12-01

    Full Text Available The measurements of pollen fall were carried out in Lublin in 1995 - 2000 years by the gravimetric method. The modified Durham sampler was applied, located at 9 m above ground level. On the base of results 6 year observations - the pollen calendar for Lublin was prepared. The following 15 plant taxa were taken under consideration: Alnus, Corylus, Cupressaceae, Populus, Fraxinus, Betula, Quercus, Pinaceae, Poaceae, Rumex, Plantago, Urtica, Chenopodiaceae, Artemisia and Ambrosia. The anemophilous plants' pollen season in Lublin began in half of February and lasted till half of September. First appeared pollen grains of decidous tress' and shrubs, then the coniferous. High values of pollen fall of these plants were noted till the end of May. Start of grass pollen season was recorded from the half of May, and at the latter part of this month, also other herbaceous plants. The highest concentrations of pollen were found in April and May when trees and shrubs pollinated. The highest annual totals were marked for plants of the following taxa: Betula, Poaceae, Pinaceae, Alnus, Urtica.

  16. Pollen production in selected species of anemophilous plants

    Directory of Open Access Journals (Sweden)

    Krystyna Piotrowska

    2012-12-01

    Full Text Available In the study, structural features of flowers of the following allergenic plant species were analysed: Betula verrucosa, Secale cereale, Rumex acetosella, Plantago major and Artemisia vulgaris. Pollen production was established by calculating the number of pollen grains produced by the stamen, flower and inflorescence. The dates of occurrence and pollen grains concentration in the air of Lublin were determined. A positive correlation was found between the length of anthers and the number of pollen grains produced. The largest number of pollen grains per anther is produced by Secale cereale (22 360, whereas the smallest one by Plantago major (5 870. The other species produced intermediate numbers of pollen grains in the anther: Betula verrucosa - 11 160, Rumex acetosella - 10 850, Artemisia vulgaris - 9 580. The birch pollen season in Lublin lasts about a month, and pollen of this taxon reaches the highest airborne concentrations among the studied taxa. Low values of pollen concentrations are characteristic for rye and plantain, whereas slightly higher values are recorded for sorrel pollen. Mugwort pollen reaches high concentrations which are noted at the beginning of August.

  17. Wood Usage and Fire Veneration in the Pamir, Xinjiang, 2500 yr BP.

    Directory of Open Access Journals (Sweden)

    Hui Shen

    Full Text Available Located on the Pamir Plateau in Xinjiang Province, China, the Ji'erzankale Necropolis dates back to 2500 yr BP. Many materials that have been unearthed in this cemetery, including shoo konghou (musical instrument, bronze mirrors and glass beads, suggest cultural transference between East and West. Furthermore, small-sized and rounded fire altars made from sweet-scented Sabina were found for the first time and regarded as implements for fire veneration. We identified 70 wooden objects from 25 tombs within the Necropolis, and found that each object had been made from one of seven tree species. Analysis revealed that the inhabitants of the region mainly used the most widely available types of wood, namely Betula and Populus. People also specifically chose inflammable Populus wood to make hearth boards and hand drills (both are used for making fire by drilling, rigid Betula wood to craft wooden plates. Salix was used for fashioning wooden sticks, while sweet-scented Sabina was the preferred choice for making fire altars. Lonicera was selected for arrow shaft manufacture and Fraxinus syriaca, which has a beautiful grain, was chosen for making musical instruments. Conscious selection of different types of wood indicates that people of the Pamir Plateau were aware of the properties of various types of timbers, and were able to exploit these properties to the full. In turn, this demonstrates their wisdom and their ability to survive in, and adapt to, their local environment.

  18. Vegetation and climate in the Western Sayan Mts according to pollen data from Lugovoe Mire as a background for prehistoric cultural change in southern Middle Siberia

    Science.gov (United States)

    Blyakharchuk, Tatiana A.; Chernova, Natalia A.

    2013-09-01

    On the basis of pollen and spore analyses and radiocarbon dating of peat deposits of Lugovoe Mire in southern Middle Siberia, changes of vegetation and climate of the Western Sayan Mts and the Khakasia Republic (Russia) since 6000 yr 14C BP (5000 cal yr BC) are found to correspond with the development of archaeological cultures and with the pollen-based palaeoclimatic reconstruction of Levina and Orlova (1993) constructed for the forest-steppe zone of the south of West Siberia. Three phases in the development of the regional vegetation (Abies, Betula, and Pinus) are distinguished in the pollen diagram of Lugovoe Mire, which form the environmental background for the archaeological cultures developed in this region. The first penetration of ancient hunting-fishing tribes into this area occurred during the ‘Abies stage' of the vegetation. Bronze Age cultures practiced agriculture and animal husbandry mostly during the ‘Betula stage'. Beginning in the Iron Age, archaeological cultures bloomed in the study area on the background of expanding Pinus sylvestris forests. The origin of all these cultures was connected with migrations of people from the southwest or southeast. An important reason for these migrations was dry climatic phases at millennial intervals, which influenced especially strongly the more southerly homelands of the migrating ancient tribes.

  19. Fire drives transcontinental variation in tree birch defense against browsing by snowshoe hares.

    Science.gov (United States)

    Bryant, John P; Clausen, Thomas P; Swihart, Robert K; Landhäusser, Simon M; Stevens, Michael T; Hawkins, Christopher D B; Carrière, Suzanne; Kirilenko, Andrei P; Veitch, Alasdair M; Popko, Richard A; Cleland, David T; Williams, Joseph H; Jakubas, Walter J; Carlson, Michael R; Bodony, Karin Lehmkuhl; Cebrian, Merben; Paragi, Thomas F; Picone, Peter M; Moore, Jeffrey E; Packee, Edmond C; Malone, Thomas

    2009-07-01

    Fire has been the dominant disturbance in boreal America since the Pleistocene, resulting in a spatial mosaic in which the most fire occurs in the continental northwest. Spatial variation in snowshoe hare (Lepus americanus) density reflects the fire mosaic. Because fire initiates secondary forest succession, a fire mosaic creates variation in the abundance of early successional plants that snowshoe hares eat in winter, leading to geographic variation in hare density. We hypothesize that fire is the template for a geographic mosaic of natural selection: where fire is greatest and hares are most abundant, hare browsing has most strongly selected juvenile-phase woody plants for defense. We tested the hypothesis at multiple spatial scales using Alaska birch (Betula neoalaskana) and white birch (Betula papyrifera). We also examined five alternative hypotheses for geographic variation in antibrowsing defense. The fire-hare-defense hypothesis was supported at transcontinental, regional, and local scales; alternative hypotheses were rejected. Our results link transcontinental variation in species interactions to an abiotic environmental driver, fire. Intakes of defense toxins by Alaskan hares exceed those by Wisconsin hares, suggesting that the proposed selection mosaic may coincide with a geographic mosaic of coevolution. PMID:19422319

  20. 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.

  1. Increasing shrub abundance and N addition in Arctic tundra affect leaf and root litter decomposition differently

    Science.gov (United States)

    McLaren, J.; van de Weg, M. J.; Shaver, G. R.; Gough, L.

    2013-12-01

    Changes in global climate have resulted in a ';greening' of the Arctic as the abundance of deciduous shrub species increases. Consequently, not only the living plant community, but also the litter composition changes, which in turn can affect carbon turnover patterns in the Arctic. We examined effects of changing litter composition (both root and leaf litter) on decomposition rates with a litter bag study, and specifically focused on the impact of deciduous shrub Betula nana litter on litter decomposition from two evergreen shrubs (Ledum palustre, and Vaccinium vitis-idaea) and one graminoid (Eriophorum vaginatum) species. Additionally, we investigated how decomposition was affected by nutrient availability by placing the litterbags in an ambient and a fertilized moist acidic tundra environment. Measurements were carried out seasonally over 2 years (after snow melt, mid-growing season, end growing season). We measured litter mass loss over time, as well as the respiration rates (standardized for temperature and moisture) and temperature sensitivity of litter respiration at the time of harvesting the litter bags. For leaves, Betula litter decomposed faster than the other three species, with Eriophorum leaves decomposing the slowest. This pattern was observed for both mass loss and litter respiration rates, although the differences in respiration became smaller over time. Surprisingly, combining Betula with any other species resulted in slower overall weight loss rates than would be predicted based on monoculture weight loss rates. This contrasted with litter respiration at the time of sampling, which showed a positive mixing effect of adding Betula leaf liter to the other species. Apparently, during the first winter months (September - May) Betula litter decomposition is negatively affected by mixing the species and this legacy can still be observed in the total mass loss results later in the year. For root litter there were fewer effects of species identity on root

  2. 庞泉沟地区山地杨桦林优势种种群格局与动态%POPULATION PATTERN AND DYNAMICS OF MOUNTAINOUS POPLAR-BIRCH FOREST IN PANGQUANGOU NATURAL RESERVE

    Institute of Scientific and Technical Information of China (English)

    田世广; 张金屯; 张钦弟; 张斌; 苏日古嘎

    2011-01-01

    Dynamic changes of forest communities in various stages are shown as the dominant population growth and demise and changes of competitive strength, this change trend can be effectively described by size structure and pattern analysis. The paper studies characteristics of dynamic change in the mountain poplar-birch in the Pangquangou National Nature Reserve. and results show that Populus trernula and Betula platyphylla and Picea wilsonii are clumped within a certain scale, Populus tremula, and Picea wilsonii occupy similar habitat. Picea wilsonii own notable advantage in the competition, and will replace Populus tremula in the succession. For population change in the community is relative stable Betula platyphylla and Betula albosinensis, long-presence, and possible form broadleaf-coniferous forest mixed forest together with Picea wilsonii.%森林群落的动态变化在各个阶段表现为优势种群数量增长和消亡及竞争强弱的变化,径级结构和格局分析能有效地描述这种变化的趋势.本文研究庞泉沟自然保护区山地杨桦林这种变化特征,结果表明群落变化过程中,一定尺度范围内的山杨、白桦、青杆在小尺度上均为集群分布,在大尺度上趋于随机分布.山杨和青杆呈明显正相关关系,占据相似的生境,青杆在竞争中占有优势,在演替过程中将取代山杨.白桦和红桦在群落变化过程中较为稳定,在演替中可能将长期存在,与青杆形成针-阔叶混交林.

  3. Study on Soil Fertility of Different Forest Types in Jialing River Source%嘉陵江源头几种林地土壤肥力状况调查

    Institute of Scientific and Technical Information of China (English)

    谭胡燕; 刘瑞英; 杨改河; 任学敏; 王得祥

    2011-01-01

    Based on analysis of soil pH, the content of organic matter and main nutrient at the different levels of soil under seven different forest types (Quercus aliena BI. Var. Acuteserrate, Betula albo-sinensis, Pinus tabulaeformis , Pinus armandii , Abies fargesii , coniferous and broad-leaved mixed forest, shrub forest)in Jialing river of source, this paper studied on soil fertility of different forest types. The result showed that the soil in Pinus armandii, Pinus tabulae formis and coniferous and broad-leaved mixed forest were near neutral, the soil in Quercus aliena BI. Var. Acuteserrate, Betula albo-sinensis and shrub forest were slightly acidic, the soil in Abies fargesii was acidic. The soil pH, the contents of soil organic matter, total N and P, alkali-hydro N and available P tended to decrease with soil depth. The soil fertility was increased in the order of Pinus armandii <Lpinus tabulae formis <coniferous and broad-leaved mixed ioresKQuercus aliena BI. Var. Acuteserrate<shrub forest<Abies fargesii<L Betula albo-sinensis.%以嘉陵江源头风景区7种林型(锐齿栎林、红桦林、油松林、华山松林、巴山冷杉林、针阔混交林及灌木林)土壤为研究对象,通过对林地土壤不同层次pH、有机质及主要养分含量的测定,分析不同林型下土壤肥力的差异状况.结果表明,华山松林、油松林和针阔混交林的土壤趋于中性,锐齿栎林、红桦林、灌木林的土壤趋于弱酸性,而巴山冷杉林的土壤呈酸性.随土壤深度增加,土壤pH升高,土壤有机质、全氮、全磷、碱解氮、有效磷含量均呈下降趋势.土壤综合肥力优劣为华山松林<油松林<针阔混交林<锐齿栎林<灌木林<巴山冷杉林<红桦林.

  4. Vegetation Dynamics in the Kenai Lowlands, Alaska during the Late Pleistocene and Holocene

    Science.gov (United States)

    Jones, M. C.; Peteet, D. M.

    2005-12-01

    The use of paleoinformation through ecosystem reconstruction can help us understand the behavior and sensitivity of the boreal forest as climate continues to change. A 2.5-meter sediment core extracted from Swanson Fen, a muskeg in the northern Kenai Lowlands on the Kenai Peninsula, Alaska, provides a sensitive Holocene paleoenvironmental record that lies in an ecotone between interior boreal forest and maritime coastal forest today. The core was sampled at 2-cm intervals and processed for pollen and spores. Five intervals were dated using AMS radiocarbon dating, and the basal macrofossils produced an age of 12,245 ±45 radiocarbon years. The central Kenai Peninsula Lowlands underwent a number of marked vegetational and climatic changes since deglaciation. Four distinct vegetation zones reveal changes starting in the late Pleistocene. The pioneer vegetation includes a dominance of herbaceous ( Artemisia, Apiaceae, Asteroideae)and shrubby ( Betula) species. The second zone (beginning at 9890±45 radiocarbon years) and marking the Holocene boundary, shows a striking increase in Polypodiaceae (ferns) and Picea (spruce) and a decrease in shrubby species such as Betula, indicative of warming. The third zone indicates a decline in Polypodiaceae and a reemergence of Betula species, while the final most recent zone reveals a rapid resurgence in Picea and Tsuga mertensiana (Mountain hemlock) species. While a general warming trend occurred following deglaciation, vegetation patterns suggest extended periods of increased precipitation, for example in the early Holocene, as is evidenced by the plethora of Polypodiaceae. A movement and an intensification of the Aleutian Low could explain these periods of increased precipitation over the Kenai Peninsula. Alternatively, this spike in Polypodiaceae can be explained by increased disturbance. The presence of 10 % Picea pollen at the base of the core suggests that one of the Picea species may have survived the last glaciation in the

  5. A tree species inventory over Europe

    Science.gov (United States)

    Ambelas Skjøth, C.; Geels, C.; Hvidberg, M.; Hertel, O.; Brandt, J.; Frohn, L. M.; Hansen, K. M.; Hedegaard, G. B.; Christensen, J. H.; Moseholm, L.

    2009-04-01

    Atmospheric transport models are used in studies of atmospheric chemistry as well as aerobiology. Atmospheric transport models in general needs accurate emissions inventories, which includes biogenic emissions such as Volatile Organic Compounds (VOCs) and pollen. Trees are important VOC and pollen sources and a needed requirement is specie distribution which takes into account important species such as Betula and Alnus. We present here a detailed tree species inventory covering Europe, parts of Africa and parts of Asia. Forest inventories have been obtained for each European country, parts of Asia and parts of Africa. The national inventories vary with respect to number of species as well as the number of sub-regions each nation is divided into. The inventories are therefore harmonised within a GIS system and afterwards gridded to the model grid defined by the EMEP model: 50 km x 50 km. The inventory is designed to be used with existing land-use data, which separates forest cover into broad leaved, mixed and conifer forests. This will be exemplified by using two different remote sensing products with different grid resolution such as GLC2000 and CLC2000 in selected areas. The final inventory includes 16 conifer species and 23 broadleaved species that are important for biogenic VOCs or pollen emission calculations. For example: Oak (Quercus), poplar (Populus), pines (Pinus), spruce (Picea), birch (Betula) and alder (Alnus). 774 regions with forest inventories are included, mainly on sub-national level. The coverage of each specie ranges from national to European scale, where the latter includes VOC and allergy relevant species such as Quercus, Alnus and Betula. The inventory is gridded to the model grid defined by the EMEP model, which is also the basis for many emissions inventories throughout Europe. The inventory is therefore prepared for easy implementation into atmospheric transport models by providing an extension to already applied land use data such as the

  6. 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

    ) 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......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...... 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...

  7. Which plant for which skin disease? Part 2: Dermatophytes, chronic venous insufficiency, photoprotection, actinic keratoses, vitiligo, hair loss, cosmetic indications.

    Science.gov (United States)

    Reuter, Juliane; Wölfle, Ute; Korting, Hans Christian; Schempp, Christoph

    2010-11-01

    This paper continues our review of scientifically evaluated plant extracts in dermatology. After plants effective against dermatophytes, botanicals with anti-edema effects in chronic venous insufficiency are discussed. There is good evidence from randomized clinical studies that plant extracts from grape vine leaves (Vitis vinifera), horse chestnut (Aesculus hippocastanum), sea pine (Pinus maritima) and butcher's broom (Ruscus aculeatus) can reduce edema in chronic venous insufficiency. Plant extracts from witch hazel (Hamamelis virginiana), green tea (Camellia sinensis), the fern Polypodium leucotomos and others contain antioxidant polyphenolic compounds that may protect the skin from sunburn and photoaging when administered topically or systemically. Extracts from the garden spurge (Euphorbia peplus) and from birch bark (Betula alba) have been shown to be effective in the treatment of actinic keratoses in phase II studies. Some plant extracts have also been investigated in the treatment of vitiligo, various forms of hair loss and pigmentation disorders, and in aesthetic dermatology. PMID:20707877

  8. 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.

  9. Nutrient fluxes from insect herbivory increase during ecosystem retrogression in boreal forest.

    Science.gov (United States)

    Metcalfe, Daniel B; Crutsinger, Gregory M; Kumordzi, Bright B; Wardle, David A

    2016-01-01

    Ecological theory, developed largely from ungulates and grassland systems, predicts that herbivory accelerates nutrient cycling more in productive than unproductive systems. This prediction may be important for understanding patterns of ecosystem change over time and space, but its applicability to other ecosystems and types of herbivore remain uncertain. We estimated fluxes of nitrogen (N) and phosphorus (P) from herbivory of a common tree species (Betula pubescens) by a common species of herbivorous insect along a -5000-yr boreal chronosequence. Contrary to established theory, fluxes of N and P via herbivory increased along the chronosequence despite a decline in plant productivity. The herbivore-mediated N and P fluxes to the soil are comparable to the main alternative pathway for these nutrients via tree leaf litterfall. We conclude that insect herbivores can make large contributions to nutrient cycling even in unproductive systems, and influence the rate and pattern of ecosystem development, particularly in systems with low external nutrient inputs.

  10. Biochemical and molecular genetic approaches on the radioprotective mechanism of natural products

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Hee; Lee, Eun Ju; Sung, Woo Kyung; Piao, Wen Hua [Kyunghee University, Seoul (Korea)

    1999-04-01

    We reported the radio-protective effect of DTT. The treatment of DTT increased cell survival after gamma-irradiation, decreased in the frequencies of micronucleus, and reduction in DNA fragmentation and apoptotic cells. Induction of apoptosis after UV-C irradiation was revealed by the changes in the relative cell death, increase in the relative amount of apoptotic cells, and the induction of DNA fragmentation. About 100 medicinal plants were purchased and methanol extract samples were prepared. Radio-protective and radio-sensitizing activities of these samples were screened. Seven samples showed above 20% radio-protective activities: Salvia miltiorrhiza, Areca catechu, Cornus officinalis, Alpiniae officinari rhizoma, Meliae fructus, Alpiniae katsumadaii semen, Betulae cortex. Acanthopanax sessiliflous showed the highest radio-sensitizing effect and 10 other samples revealed moderate activities: Melia japonica, Agastache rugosa, Platycodon gradiflorum, Broussonetia bazinoki, Angelica gigas, Inula helenium, Chelidonium majus, Pulsatilla koreana, Oldenlandia diffusa, Dioscorea batatas. (author). 49 refs., 9 figs., 7 tabs.

  11. Determination of de novo and pool emissions of terpenes from four common boreal/alpine trees by 13CO2 labelling and PTR-MS analysis.

    Science.gov (United States)

    Ghirardo, Andrea; Koch, Kristine; Taipale, Risto; Zimmer, Ina; Schnitzler, Jörg-Peter; Rinne, Janne

    2010-05-01

    Boreal forests emit a large amount of monoterpenes into the atmosphere. Traditionally these emissions are assumed to originate as evaporation from large storage pools. Thus, their diurnal cycle would depend mostly on temperature. However, there is indication that a significant part of the monoterpene emission would originate directly from de novo synthesis. By applying 13CO2 fumigation and analyzing the isotope fractions with proton transfer reaction mass spectrometry (PTR-MS) and classical GC-MS, we determined the fractions of monoterpene emissions originating from de novo biosynthesis in Pinus sylvestris (58%), Picea abies (33.5%), Larix decidua (9.8%) and Betula pendula (100%). Application of the observed split between de novo and pool emissions from P. sylvestris in a hybrid emission algorithm resulted in a better description of ecosystem scale monoterpene emissions from a boreal Scots pine forest stand. PMID:20040067

  12. Paper birch: Sentinels of climate change in the Niobrara River Valley, Nebraska

    Science.gov (United States)

    Stroh, Esther D.

    2011-01-01

    The Niobrara River Valley in the northern Great Plains supports scattered stands of paper birch (Betula papyrifera Marsh), a species more typical of boreal forests. These birch stands are considered to be relictual populations that have persisted since the end of the Wisconsin glaciation. Localized summer microclimates have likely facilitated the persistence of birch populations in a region otherwise unsuitable for the species. Dieback of canopy-sized birch has been observed throughout the valley in recent years, although no onset dates are documented. Changes in spring weather patterns may be causing rootlet injury so that trees die in spite of the still-cool summer microclimates. Current weather patterns, combined with little evidence of recruitment of young birch and great geographic distances from potential immigrant sources, make the future persistence of birch in the Niobrara River Valley stands uncertain.

  13. Stimulated production of steroids in Inonotus obliquus by host factors from birch.

    Science.gov (United States)

    Wang, Lian-Xia; Lu, Zhen-Ming; Geng, Yan; Zhang, Xiao-Mei; Xu, Guo-Hua; Shi, Jin-Song; Xu, Zheng-Hong

    2014-12-01

    Steroids was considered as one of the bioactive components in Inonotus obliquus, while this kind of secondary metabolites are less accumulated in cultured mycelia. In this study, effect of extracts from bark and core of host-related species, birch (Betula platyphylla Suk.), on steroid production of I. obliquus in submerged culture were evaluated. The results showed that all dosages (0.01 and 0.1 g/L) of aqueous extracts and methanol extracts from birch bark and birch core possessed significantly stimulatory effect on steroid production of I. obliquus (P obliquus simultaneously increased in the presence of aqueous extract and methanol extract from birch bark. The results presented herein indicate that extracts from birch bark could act as an inducer for steroid biosynthesis of I. obliquus. PMID:25027706

  14. Значение бонитета условий местопроизрастания березы в экологии Inonotus obliquus (Pers. ) Pil

    OpenAIRE

    Баландайкин, Михаил

    2012-01-01

    Устанавливается специфика влияние классов бонитета Betula pendula Roth. на степень встречаемости в формируемых ею насаждениях патологического агента Inonotus obliquus (Pers.) Pil.

  15. ВЛИЯНИЕ ВЕРТИКАЛЬНОЙ СТРУКТУРЫ БЕРЕЗОВЫХ НАСАЖДЕНИЙ НА РАСПРОСТРАНЕННОСТЬ INONOTUS OBLIQUUS (PERS.) PIL

    OpenAIRE

    Баландайкин, М.

    2013-01-01

    В настоящей работе речь идет о нативной согласованности дисперсии Inonotus obliquus (Pers.) Pil. и формы древостоя Betula pendula Roth. Также рассматриваются некоторые соподчиненные закономерности.

  16. Variations of population structure and important value of the main edificators along the elevation gradient on the northern slope of Changbai Mountain

    Institute of Scientific and Technical Information of China (English)

    JIANGPing; YEJi; DENGHong-bing; CUIGUO-fa

    2003-01-01

    From 700 m to 1900 m on the northern slope of Changbai Mountain, 13 plots with an interval of 100 m in elevation were investigated to study the variations of population structure and important value of the main edificators along the elevation gradient. In their core distribution areas, most of the edificators had healthy population structure and could regenerate smoothly except Larix olgensis, but important value of Larix olgensis had no obvious variations with elevation changes, which showed that Larix olgensis had its own particularity and strong adaptability. At high elevation above 1800 m, Betula ermanfi was the only species that could form a mono-dominant community. Important values of Pinus koraiensis and Acer mono had similar changing trends, and they had the similar ecological adaptabilities.

  17. A longitudinal study of memory advantages in bilinguals.

    Directory of Open Access Journals (Sweden)

    Jessica K Ljungberg

    Full Text Available Typically, studies of cognitive advantages in bilinguals have been conducted previously by using executive and inhibitory tasks (e.g. Simon task and applying cross-sectional designs. This study longitudinally investigated bilingual advantages on episodic memory recall, verbal letter and categorical fluency during the trajectory of life. Monolingual and bilingual participants (n=178 between 35-70 years at baseline were drawn from the Betula Prospective Cohort Study of aging, memory, and health. Results showed that bilinguals outperformed monolinguals at the first testing session and across time both in episodic memory recall and in letter fluency. No interaction with age was found indicating that the rate of change across ages was similar for bilinguals and monolinguals. As predicted and in line with studies applying cross-sectional designs, no advantages associated with bilingualism were found in the categorical fluency task. The results are discussed in the light of successful aging.

  18. Characterisation of Holocene plant macrofossils from North Spanish ombrotrophic mires: vascular plants

    Directory of Open Access Journals (Sweden)

    M. Souto

    2016-06-01

    Full Text Available Methods and criteria that were used to identify plant macrofossils from four ombrotrophic mires in northern Spain are presented. Twelve monocotyledon and ten dicotyledon species were recorded. Some were identified from vegetative or reproductive macroremains (Eriophorum angustifolium, Molinia caerulea, Calluna vulgaris, Erica mackaiana, Erica tetralix, Potentilla erecta, while others were recognised only by their fruits (Rhynchospora alba, Carex durieui, Carex echinata, Carex binervis, Carex demissa, Betula alba, seeds (Juncus squarrosus, Juncus bulbosus, Luzula multiflora, Narthecium ossifragum, Drosera rotundifolia, Drosera intermedia, Caltha palustris, Daboecia cantabrica, rhizome fragments with remains of leaves (Agrostis curtisii, or twigs with buds and leaves (Vaccinium myrtillus. Descriptions of the specific distinctive characters for the plant macrofossils that were recorded are accompanied by illustrations that facilitate their interpretation. Dichotomous identification keys are also provided.

  19. Chemical Analysis and Biological Activity of Jordanian Chamomile Extracts

    Directory of Open Access Journals (Sweden)

    Nawal Hassan Al Bahtiti

    2012-02-01

    Full Text Available The Jordanian chamomile (Matricaria chamomilla has been researched more thoroughly to evaluate its useful properties. It is investigated and found that Jordanian chamomile is rich in phenolic compounds, with beneficial biological activities. By applying the most promising HPLC method, the content of total phenolics in methanolic extract was determined according to the Folin-Clocalteu procedure, and was found (GAE>20 mg/g. The flavonoid types were found as flavones and flavonolos.The minimum inhibitory concentration values for methanolic extracts of Jordanian chamomile were determined for different kinds of bacteria. The extracts have activity against Staphylococcus aurous, candida albicans, Esherichia Coli, Betula pubescens and Pinus sylvestris. The activity has been observed to be due to the tannins and a pigenin present in the extract. To utilize these significant sources of natural compounds, further characterization of phenolic composition is needed.

  20. Managing invasive populations of Asian longhorned beetle and citrus longhorned beetle: a worldwide perspective.

    Science.gov (United States)

    Haack, Robert A; Hérard, Franck; Sun, Jianghua; Turgeon, Jean J

    2010-01-01

    The Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky), and citrus longhorned beetle (CLB), Anoplophora chinensis (Forster) (Coleoptera: Cerambycidae), are polyphagous xylophages native to Asia and are capable of killing healthy trees. ALB outbreaks began in China in the 1980s, following major reforestation programs that used ALB-susceptible tree species. No regional CLB outbreaks have been reported in Asia. ALB was first intercepted in international trade in 1992, mostly in wood packaging material; CLB was first intercepted in 1980, mostly in live plants. ALB is now established in North America, and both species are established in Europe. After each infestation was discovered, quarantines and eradication programs were initiated to protect high-risk tree genera such as Acer, Aesculus, Betula, Populus, Salix, and Ulmus. We discuss taxonomy, diagnostics, native range, bionomics, damage, host plants, pest status in their native range, invasion history and management, recent research, and international efforts to prevent new introductions. PMID:19743916

  1. 哈尔滨市3种阔叶树树干钠镁钙铝纵向变化特征%Longitudinal Variation in Na,Mg,Ca,Al of Trunk for Three Kinds of Broadleaf Tree in Harbin City

    Institute of Scientific and Technical Information of China (English)

    于辉; 高禾

    2013-01-01

      以东北林业大学城市林业示范研究基地内生长的黄波罗、蒙古栎和白桦为研究对象,分析不同阔叶树树干不同高度 Na 、Mg 、Ca 、Al 元素纵向变化特征,探讨3树种对以上元素的运移速率。结果表明,在1958年前和1959—1962年间,除了 Mg 元素,黄波罗树干其他3种元素纵向格局为根茎含量大于胸径。3树种在1963—2007年间各时间段,以上元素纵向变化呈现出在胸径或1/2树高为最低的凹形曲线,或为最高值的凸形曲线,或纵向变化较为平缓等多种形式。同一时期,各树种树干 Al 纵向变幅最高;其他树种其余3种元素纵向变幅较低且值相当。树干中4种元素纵向运移速率由易到难排序分别为:黄波罗 Mg > Ca > Na > Al ;蒙古栎 Ca > Na > Al > Mg ;白桦 Mg > Al > Ca > Na 。蒙古栎对 Na 、黄波罗和白桦对 Mg 、蒙古栎和白桦对 Al 、Ca 元素的迁移能力较强。%  Taking Phellodendron amurense , Quercus mongolica & Betula platy phylla grew in Urban Forestry Demonstration Research Base of Northeast Forestry University as the objects ,longitudinal variation of Na ,Mg , Ca ,Al element of trunks at different heights for different broadleaf trees were analyzed ;migration rate of the above elements of three species were explored .Result shows that ,in the years before 1958 and from 1959 to 1962 ,in ad-dition to Mg element ,longitudinal pattern of the other three elements for trunk of Phellodendron amurense is rhizo-me content > DBH ;in the years from 1963 to 2007 ,the longitudinal changes of the above elements among the three species show multiple forms (the lowest concave curve ,convex curve of the highest value ,more gentle longitudinal change ) in DBH or 1/2 height of tree height .During the same period ,the vertical amplitude of Al of trunks for each species is the most highest ;the longitudinal amplitude of the other three elements of other

  2. Interspecific differences in foliar 1 PAHs load between Scots pine, birch, and wild rosemary from three polish peat bogs.

    Science.gov (United States)

    Mętrak, Monika; Aneta, Ekonomiuk; Wiłkomirski, Bogusław; Staszewski, Tomasz; Suska-Malawska, Małgorzata

    2016-08-01

    Pine needles are one of the most commonly used bioindicators of polycyclic aromatic hydrocarbons (PAHs) in the environment. Therefore, the main objective of the current research was the assessment of PAHs accumulation potential of Scots pine (Pinus sylvestris L.) needles in comparison to wild rosemary (Rhododendron tomentosum Harmaja) and birch (Betula spp.) leaves. Our study was carried out on three peat bogs subjected to different degree of anthropopression, which gave us also the opportunity to identify local emission sources. Pine needles had the lowest accumulation potential from all the studied species. The highest accumulation potential, and hence carcinogenic potential, was observed for wild rosemary leaves. As far as emission sources are concerned, the most pronounced influence on atmospheric PAHs loads had traditional charcoal production, resulting in great influx of heavy PAHs. Observed seasonal changes in PAHs concentrations followed the pattern of winter increase, caused mainly by heating season, and summer decrease, caused mainly by volatilization of light PAHs. PMID:27393196

  3. A 1.5 Ma sporopollen record of paleoecologic environment evolution in the central Chinese Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    WU Fuli; FANG Xiaomin; MA Yuzhen; AN Zhisheng; LI Jijun

    2004-01-01

    A 1.5 Ma sporopollen record was obtained from a continuous loess-paleosol sequence at Chaona in the central Chinese Loess Plateau. It shows that (1) arid herbs of largely Artemisia and Chenopodiaceae and arbors of mainly Pinus, Betula and Quercus dominate loess and paleosol, respectively, reflecting cycles of cold-dry and warm-humid conditions of glaciation and interglaciation; (2) that similar vegetation pattern and cold-dry condition were found in times of unusual thick and coarse loesses L9 and L15, which have been regarded as two extremely cold and dry times as indicated by inorganic climatic proxies; and (3) that shifts of vegetations from earlier forest-steppe to open-forest and steppe and then to steppe were found at 0.95 and 0.5 Ma, implying a stepwise of drying of the Loess Plateau in the Quaternary.

  4. 东北长白山垂直林带下现代表土花粉与植被关系%Pollen Record of Surface Sediments from Vertical Forest Zones of Changbai Mountain, Northeast China and Their Relations to the Modern Vegetation

    Institute of Scientific and Technical Information of China (English)

    孙湘君; 罗运利; 田军; 吴玉书

    2003-01-01

    Twenty-nine surface samples (mosses) from five vertical distribution vegetation zones inChangbai Mountain, Northeast China have been palynologically analyzed and the results were tested bycorrespondence analysis. The results show that, except a few samples, arboreal pollen is predominant inalmost all pollen assemblages; Pinus and Betula are the main pollen types in quantities and they are foundin all vegetation zones of Changbai Mountain. The highest pollen proportion of Pinus occurs in the mixedconifer and broadleaved forest where Pinus koraiensis is the main component; Betula pollen is found inhigh percentage in both subalpine B. ermanii forest and broadleaved deciduous forest predominated byBetula and Quercus; in the former Betula pollen is accompanied by cold-tolerant shrub such as Rhodo-dendron; whereas in the latter it appears a large amount of fern spores. Pollen assemblage of broadleaveddeciduous forests is marked by high diversity and proportions of deciduous trees and a large number of fernspores. Subalpine conifer forest is distinguished by high percentage of Picea pollen. Although tree pollenis slightly dominated, very few or absent of fern spores and increasing of herb and small shrub pollenproportions, particularly predominance of Rhododendron in herbaceous pollen and occurrence of tundraindicator type-Dryas pollen distinguish pollen assemblages of alpine tundra.%在长白山北坡5个垂直植被带的林下采集29个表土(苔藓)样品进行孢粉分析,同时将其结果作对应分析.结果表明,除个别样品,在长白山垂直植被带的孢粉组合中乔木花粉占优势,其中以松属和桦木属最多,在各植被带均有分布.松属花粉最高含量出现在以红松为主的针阔混交林带的孢粉组合中;桦木属花粉则大量见于亚高山岳桦林带和以栎桦为主的阔叶落叶林带,但前者伴有耐寒、早的小灌丛杜鹃花属花粉,而在后者中则见有大量蕨类孢子.阔叶落叶林带的孢粉组

  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. 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.

  7. Properties of Modified Phenol-Formaldehyde Adhesive for Plywood Panels Manufactured from High Moisture Content Veneer

    Directory of Open Access Journals (Sweden)

    Pavlo Bekhta

    2015-01-01

    Full Text Available This paper presents the results of laboratory investigations of bonding high moisture content (15 % birch veneers (Betula pubescens Ehrh. with the use of modifi ed phenol-formaldehyde (PF resin. Wheat starch, rye flour, resorcinol and phenol-resorcinol-formaldehyde resin were chosen as modifying agents. Dynamic viscosity, hydrogen ions concentration, solid content, curing time, pot life of developed adhesive compositions and shear strength of plywood samples were evaluated. ANOVA analysis has shown that type, mixture and content of modifying agents affect significantly the mechanical performance of plywood panels. The obtained results of shear strength values were above the standard requirements (1 N/mm2, and the properties of samples met the European standard EN 314-2 for gluing quality of class 3 and such plywood panels can be used in exterior conditions.

  8. Effect of Tree Species on Enzyme Secretion by the Shiitake Medicinal Mushroom, Lentinus edodes (Agaricomycetes).

    Science.gov (United States)

    Plotnikov, Evgeny V; Glukhova, Lubov B; Sokolyanskaya, Ludmila O; Karnachuk, Olga V; Solioz, Marc

    2016-01-01

    We compared cold and hot wood extracts of 3 endemic Siberian trees-namely, Prunus padus (bird cherry), Populus tremula (aspen), and Betula sp. (birch)-on biomass production and laccase and peroxidase secretion in submerged cultures by the medicinal mushroom Lentinus edodes. Of the conditions tested, only hot Prunus extracts stimulated biomass production, whereas all extracts stimulated laccase and peroxidase secretion, albeit to different extents. A large, differential stimulation of manganese peroxidase was observed by hot Prunus extracts. The results highlight important differences between tree species in the stimulation of biomass and enzyme production by L. edodes and point to potentially interesting stimulatory factors present in hot Prunus extracts. These findings are of relevance in the use of L. edodes for medicinal or biotechnological applications. PMID:27649732

  9. METHODS OF BIOMONITORING IN URBAN ENVIRONMENT: ALLERGENIC POLLEN IN WESTERN ROMANIA AND RELATIONSHIPS WITH METEOROLOGICAL VARIABLES

    Directory of Open Access Journals (Sweden)

    Nicoleta IANOVICI

    2015-12-01

    Full Text Available Biomonitoring results showed that a total of 23 pollen types were located in the air of the study area. The analysis of the airborne pollen content concerned 20 taxa, whose pollen has allergenic properties and occurs in large quantities in the air of Timisoara: Alnus, Taxaceae/Cupressaceae, Salix, Populus, Ulmus, Fraxinus, Juglans, Quercus, Tilia, Pinaceae, Corylus, Carpinus, Betula, Poaceae, Rumex, Plantago, Urticaceae, Chenopodiaceae/Amaranthaceae, Ambrosia and Artemisia. Analysis of the pollen count in Timisoara was performed on the basis of the data collected in the year 2009. Ambrosia artemisiifolia, Urticaceae and Poaceae reached the highest atmospheric pollen concentrations in Timisoara. Multiple regression analysis was found to be a very valuable tool for identifying the weather variables most closely associated with atmospheric pollen seasons.

  10. Determination of selected microelements in polish herbs and their infusions

    Energy Technology Data Exchange (ETDEWEB)

    Kalny, Piotr [Medical University of Warsaw, Department of Drugs Analysis, Banacha 1, 02-091 Warsaw (Poland); Fijalek, Zbigniew [Medical University of Warsaw, Department of Drugs Analysis, Banacha 1, 02-091 Warsaw (Poland); National Medicines Institute, Department of Pharmaceutical Chemistry, Chelmska 30/34, 00-725 Warsaw (Poland); Daszczuk, Anna [Medical University of Warsaw, Department of Drugs Analysis, Banacha 1, 02-091 Warsaw (Poland); Ostapczuk, Peter [Research Center of Juelich, Department of Safety and Radiation Protection, Leo-Brand Str. 1, D-52425 Juelich (Germany)]. E-mail: p.ostapczuk@fz-juelich.de

    2007-08-01

    Ba, Cd, Cr, Cu, Fe, Ni, Pb and Zn were determined in birch leaves (Folium Betulae), dandelion roots (Radix Taraxacae), hawthorn blossom (Inflorescentia Crataegi) and their infusions by graphite furnace atomic absorption spectrometry (GFAAS) after microwave digestion of plant samples. Infusions were made from herbs according to prescription for patients, provided by the producer of medicine on the package. The results obtained were compared with daily requirements for each element. Results show high content of cadmium in the medicinal plants analyzed. The highest level in infusions was observed for Ni and Zn (over 90% of the total element concentration for Ni and in most cases over 50% for Zn), and the lowest for Cd and Pb. The calculated daily intake of majority of the analyzed elements was very low (under 1% of daily requirements)

  11. Increased ectomycorrhizal fungal abundance after long-term fertilization and warming of two arctic tundra ecosystems

    DEFF Research Database (Denmark)

    Clemmensen, Karina Engelbrecht; Michelsen, Anders; Jonasson, Sven Evert;

    2006-01-01

    the response in EM fungal abundance to long-term warming and fertilization in two arctic ecosystems with contrasting responses of the EM shrub Betula nana. •  Ergosterol was used as a biomarker for living fungal biomass in roots and organic soil and ingrowth bags were used to estimate EM mycelial production......•  Shrub abundance is expected to increase with enhanced temperature and nutrient availability in the Arctic, and associated changes in abundance of ectomycorrhizal (EM) fungi could be a key link between plant responses and longer-term changes in soil organic matter storage. This study quantifies....... We measured 15N and 13C natural abundance to identify the EM-saprotrophic divide in fungal sporocarps and to validate the EM origin of mycelia in the ingrowth bags. •  Fungal biomass in soil and EM mycelial production increased with fertilization at both tundra sites, and with warming at one site...

  12. Habitat Ecology of Himalayan Musk Deer (Moschus chrysogaster in Manaslu Conservation Area, Nepal

    Directory of Open Access Journals (Sweden)

    Xiuxiang Meng

    2012-01-01

    Full Text Available The Himalayan musk deer (Moschus chrysogaster is an endangered species found in the Himalayan region of Nepal. This research was conducted in the Manaslu Conservation Area to explore the deers general population status, distribution, habitat preference and conservation threats. Musk deer are distributed within the altitudinal range of 3128-4039 m spanning 35.43 km2, with the most potential habitat in the Prok VDC (Village Development Committee. Within this area the Musk deer highly preferred altitudes between 3601-3800 m, with a 21-30 slope, 26-50% crown cover and 26-50% ground cover. There are significant differences in the use of different habitat types in terms of altitude, slope, crown cover, ground cover and topography. The preferred tree species were Abies spectabilis, Betula utilis and Rhododendron species. Poaching of deer for their musk is the major conservation threat.

  13. Palynological investigation of a Holocene profile section from the Palaeo-Gaxun-Nur-Basin

    Institute of Scientific and Technical Information of China (English)

    D. Demske; S. Mischke

    2003-01-01

    Palynological investigations on lacustrine sediment samples revealed ageneral dominance of open Artemisia-Chenopodiaceae vegetation in the Palaeo-Gaxun- Nur-Basin (Inner Mongolia) between 5250 and 3500 cal. aBP. Riverside woods (Hippophae, Populus) developed between 3500-3250 cal. aBP and reflect moister growing conditions. During the following moist-dry transition pronounced cooling occurred around 3000 cal. aBP, in upper elevations favouring the spread of montanewoods (Picea, Betula). Aridity strongly increased from 2900 to 2700 cal. aBP. The recorded vegetational and environmental changes after 3500 cal. aBP can be correlated with glacier advances in the mountains and with a humid phase in the Tengger Shamo followed by desertification.

  14. Post-dispersal seed predation of woody forest species limits recolonization of forest plantations on ex-arable land

    DEFF Research Database (Denmark)

    Bruun, Hans Henrik; Valtinat, Karin; Kollmann, Johannes;

    2010-01-01

    Reforestation of ex-arable land in temperate regions increases the area of potential habitat for forest plants. However, the herbaceous plant layer of these plantations contains fewer forest species than comparable plantations at continuously forested sites. One of the reasons for this might......-generation forest plantations on ex-arable land and re-planted clear-cuts on continuously forested land. There was no recruitment following the experimental sowing of six commonwoody species (Alnus glutinosa, Betula pendula, Frangula alnus, Sambucus nigra, Sorbus aucuparia and Sorbus intermedia). Thus......, the colonization of forest plantations by native shrubs and trees appears to be habitat-limited; the only exception being Rhamnus catharticus, for which poor dispersal ability may be more important. Post-dispersal seed predation of forest shrubs and trees was marked, especially in relatively small and isolated...

  15. Human-ecosystem interactions in relation to Holocene environmental change in Port Joli Harbour, southwestern Nova Scotia, Canada

    Science.gov (United States)

    Neil, Karen; Gajewski, Konrad; Betts, Matthew

    2014-03-01

    A high-resolution pollen record from Path Lake in Port Joli Harbour, Nova Scotia, Canada, provides a paleo-ecological perspective on Holocene climate and vegetation variability within the context of local archaeological research. Pollen assemblages in the early Holocene reflect a post-glacial forest dominated by Pinus, Tsuga, Betula and Quercus. During this time, a lower frequency of radiocarbon dated cultural material suggests lower human settlement intensity. Shallow water aquatic (Isoetes) and wetland (Alnus, Sphagnum) taxa increased after 3400 cal yr BP in response to a transition towards wetter climatic conditions. Culturally significant periods, where settlement intensity increased in the Maritimes and Maine, coincide with maximum values of reconstructed total annual precipitation, suggesting that environmental conditions may have influenced prehistoric human activity. European settlement, after 350 cal yr BP, was marked by a rise in Ambrosia. The impact of anthropogenic fire disturbances on the landscape was evidenced by peak charcoal accumulations after European settlement.

  16. Biomonitoring for metal contamination near two Superfund sites in Woburn, Massachusetts, using phytochelatins

    Energy Technology Data Exchange (ETDEWEB)

    Gawel, James E.; Hemond, Harold F

    2004-09-01

    Characterizing the spatial extent of groundwater metal contamination traditionally requires installing sampling wells, an expensive and time-consuming process in urban areas. Moreover, extrapolating biotic effects from metal concentrations alone is problematic, making ecological risk assessment difficult. Our study is the first to examine the use of phytochelatin measurements in tree leaves for delimiting biological metal stress in shallow, metal-contaminated groundwater systems. Three tree species (Rhamnus frangula, Acer platanoides, and Betula populifolia) growing above the shallow groundwater aquifer of the Aberjona River watershed in Woburn, Massachusetts, display a pattern of phytochelatin production consistent with known sources of metal contamination and groundwater flow direction near the Industri-Plex Superfund site. Results also suggest the existence of a second area of contaminated groundwater and elevated metal stress near the Wells G and H Superfund site downstream, in agreement with a recent EPA ecological risk assessment. Possible contamination pathways at this site are discussed.

  17. Aeropalynologic analysis of Timisoara (Romania during 2006 year

    Directory of Open Access Journals (Sweden)

    Nicoleta IANOVICI

    2007-05-01

    Full Text Available This article presents the results of a one year qualitative-quantitative study of airborne pollen. The objective of the investigation was to analyse the daily presence and distribution of pollen and to identify the pollen types that are abundantly represented in the atmosphere of the city of Timisoara. A continuous aeropalynologic survey was accomplished between 1 mai 2006 and 8 octombrie 2006. Plants with anemophilous pollination were the best represented: Pinaceae, Poaceae, Plantago, Rumex, Urtica, Chenopodiaceae/Amaranthaceae, Artemisia, Ambrosia, Fraxinus, Salix, Betula, Carpinus, Quercus, Juglans, Platanus, Morus, Tilia. The total pollen spectrum was represented by 17 pollen types. Ambrosia artemisiifolia pollen types was dominant. The highest level of pollen emission was recorded during August-September.

  18. Spontaneous changes a basis for new ornamental woody plant cultivars

    Directory of Open Access Journals (Sweden)

    Đukić Matilda

    2006-01-01

    Full Text Available In nursery stock production of some ornamental woody plants the appearance of spontaneous variability was identified in the form of atypical pigmentation of leaves (albinism, variegated, red colored, leaves shape (jaggy and dwarfs. Mutated plants with variegated leaves were observed among hybrid plane (Platanus x acerifolia (Ait. Willd., Siberian elm (Ulmus pumila L., laurel cherry (Prunus laurocerasus L. and Lawson false-cypress (Chamaecyparis lawsoniana (Murr. Parl. Seedlings. The type of variegation and frequency were analyzed. Among plane tree and Siberian elm seedlings there were observed red colored leaves. Atypical, jaggy shaped leaves were found among laurel cherry seedlings. Dwarf growth was identified at Siberian elm and birch (Betula pendula Roth. where also found fruits at one year seedling. There were not significant differences in some morphological and physiological properties in plane tree seedlings with various pigmented leaves. .

  19. 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.

  20. PURIFICATION OF HARDWOOD-DERIVED AUTOHYDROLYSATES

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    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.

  1. A precise study on effects that trigger alkaline hemicellulose extraction efficiency.

    Science.gov (United States)

    Hutterer, Christian; Schild, Gabriele; Potthast, Antje

    2016-08-01

    The conversion of paper-grade pulps into dissolving pulps requires efficient strategies and process steps to remove low-molecular noncellulosic macromolecules generally known as hemicelluloses. Current strategies include alkaline extractions and enzymatic treatments. This study focused on the evaluation of extraction efficiencies in alkaline extractions of three economically interesting hardwood species: beech (Fagus sylvatica), birch (Betula papyrifera), and eucalyptus (Eucalyptus globulus). Substrate pulps were subjected to alkaline treatments at different temperatures and alkalinities using white liquor as the alkali source, followed by analyses of both pulps and hemicellulose-containing extraction lyes. The extracted hardwood xylans have strong potential as an ingredient in the food and pharmaceutical industries. Subsequent analyses revealed strong dependencies of the extraction efficiencies and molar mass distributions of hemicelluloses on the process variables of temperature and effective alkalinity. The hemicellulose content of the initial pulps, the hardwood species, and the type of applied base played minor roles. PMID:27163434

  2. Betulin Complex in γ-Cyclodextrin Derivatives: Properties and Antineoplasic Activities in In Vitro and In Vivo Tumor Models

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    Florina Bojin

    2012-11-01

    Full Text Available Given the present high incidence of melanoma and skin cancer, interest in potential drugs of plant origin has increased significantly. Pentacyclic lupane-type triterpenes are widely distributed in plants, offering numerous pharmacological benefits. Betulin is an important compound in the bark of Betula pendula Roth and has important therapeutic properties, including antitumor activities. Its biological effect is limited by its poor water solubility, which can be improved by cyclodextrin complexation. The best results have been obtained by using a novel cyclodextrin derivative, octakis-[6-deoxy-6-(2-sulfanyl ethanesulfonate]-γ-CD. The complexes between betulin and the previously mentioned cyclodextrin were analyzed by scanning electron microscopy (SEMand differential scanning calorimetry (DSC and pharmacologically evaluated in vitro (MTT and immunocytochemistry tests and in vivo in C57BL/6J mice. The solubility of betulin is improved by cyclodextrin complexation, which creates a stable complex that improves the in vitro and in vivo properties of the active compound.

  3. Enzymological study of the evolution of the technogenic soil submitted to biological recultivation in Bozanta Mare (Maramures county, north-western Romania

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    Cristian Felix BLIDAR

    2009-11-01

    Full Text Available This paper summarizes our research work regarding the dynamics of vegetation growth of miscellaneous species of trees planted and monitored in the particular environment of the tailing pond in Bozanta Mare (Maramures County. The structure of soil bearing high content of heavy metals and cyanides considerably impacts the ecologic conditions of tailing ponds. Aspects related to soil characteristics (such as structure, size of particles, porosity, texture, chemical composition are included. In the framework of our experiment we have planted seedlings belonging to four species of trees: Quercus petraea, Populus tremula, Betula verrucosa, Salix caprea. Our aim was to study the evolution of enzyme activities. Our contribution, based on the outcomes of our research, consists in the formulation of functional correlations spotted between cormophites and enzyme activities, between the species of trees and their environmental underlying conditions, with the overarching goal to optimize the activities undertaken in order to alleviate the tailing ponds inherent to mining activities.

  4. Two new species of Oobius Trjapitzin (Hymenoptera, Encyrtidae) egg parasitoids of Agrilus spp. (Coleoptera, Buprestidae) from the USA, including a key and taxonomic notes on other congeneric Nearctic taxa

    Science.gov (United States)

    Triapitsyn, Serguei V.; Petrice, Toby R.; Gates, Michael W.; Bauer, Leah S.

    2015-01-01

    Abstract Oobius Trjapitzin (Hymenoptera, Encyrtidae) species are egg parasitoids that are important for the biological control of some Buprestidae and Cerambycidae (Coleoptera). Two species, Oobius agrili Zhang & Huang and Oobius longoi (Siscaro), were introduced into North America for classical biocontrol and have successfully established. Two new native North American species that parasitize eggs of Agrilus spp. (Buprestidae) are described and illustrated from the USA: Oobius minusculus Triapitsyn & Petrice, sp. n. (Michigan), an egg parasitoid of both Agrilus subcinctus Gory on ash (Fraxinus spp.) and Agrilus egenus Gory on black locust (Robinia pseudoacacia L.) trees, and Oobius whiteorum Triapitsyn, sp. n. (Pennsylvania), an egg parasitoid of Agrilus anxius Gory on European white birch (Betula pendula Roth). A taxonomic key and notes on the Nearctic native and introduced Oobius species are also included. PMID:25931963

  5. Two new species of Oobius Trjapitzin (Hymenoptera, Encyrtidae egg parasitoids of Agrilus spp. (Coleoptera, Buprestidae from the USA, including a key and taxonomic notes on other congeneric Nearctic taxa

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    Serguei V. Triapitsyn

    2015-04-01

    Full Text Available Oobius Trjapitzin (Hymenoptera, Encyrtidae species are egg parasitoids that are important for the biological control of some Buprestidae and Cerambycidae (Coleoptera. Two species, O. agrili Zhang & Huang and O. longoi (Siscaro, were introduced into North America for classical biocontrol and have successfully established. Two new native North American species that parasitize eggs of Agrilus spp. (Buprestidae are described and illustrated from the USA: O. minusculus Triapitsyn & Petrice, sp. n. (Michigan, an egg parasitoid of both A. subcinctus Gory on ash (Fraxinus spp. and A. egenus Gory on black locust (Robinia pseudoacacia L. trees, and O. whiteorum Triapitsyn, sp. n. (Pennsylvania, an egg parasitoid of A. anxius Gory on European white birch (Betula pendula Roth. A taxonomic key and notes on the Nearctic native and introduced Oobius species are also included.

  6. VOC emissions from beech, birch, and oak

    Science.gov (United States)

    Wildt, J.; Folkers, A.; Koch, N.; Kleist, E.

    2003-04-01

    VOC emissions from beech (Fagus sylvatica), birch (Betula pendula), and oak (Quercus robur) were studied in continuously stirred tank reactors. Oak emitted nearly exclusively isoprene. The dependence of these isoprene emissions on temperature and photosynthetic radiation (PAR) could quite well be described with existing algorithms and the emission factors were fairly constant. Beech and birch emitted mainly short chained oxygenated VOC and monoterpenes. Temperature and PAR dependence of monoterpene emissions were superimposed by a slow frequency modulation. Hence, descriptions of these emissions with existing algorithms were not successful. Moreover, in some cases the emission pattern switched drastically. For birch it was observed that the plant switched from a sesquiterpene emitter to a monoterpene emitter. emission pattern plants. Emissions of ethanol, acetaldehyde, and methanol were not affected by PAR. Here, the emission factors are determined by other factors not included in existing algorithms.

  7. Is the Growth of Birch at the UPPER Timberline in the Himalayas Limited By Moisture or By Temperature?

    Science.gov (United States)

    Liang, E.; Dawadi, B.; Pederson, N.; Eckstein, D.

    2014-12-01

    Birch (Betula) trees and forests are found across much of the temperate and boreal zones of the Northern Hemisphere. Yet, despite being an ecologically-significant genus, it is much less-well studied compared to common genera like Pinus, Picea, Juniperus, Quercus, and Fagus. In the Himalayas, Himalayan birch (Betula utilis) is a widespread, important broadleaf timberline species that survives in mountain rain shadows via access to water from snowmelt. Because precipitation in the Nepalese Himalayas decreases with increasing elevation, we hypothesized that the growth of birch at the upper timberlines between 3,900 and 4,150 m a.s.l. is primarily limited by moisture availability rather than by low temperature. To verify this assumption, a total of 292 increment cores were extracted from 211 birch trees at nine timberline sites. The synchronous occurrence of narrow rings and high inter-series correlations within and among sites evidenced a reliable cross-dating and a common climatic signal in the tree-ring widths variations. From March-May, all nine tree-ring width site chronologies showed a strongly positive response to total precipitation and a less strongly negative response to temperature. During the instrumental meteorological record (after 1960), years with a high percentage of missing rings coincided with pre-monsoon drought events. Periods of below-average growth are in phase with well-known drought events all over monsoon Asia, showing additional evidence that Himalayan birch growth at the upper timberlines is persistently limited by moisture availability. Our study describes the rare case of a drought-induced altitudinal timberline that is composed by a broadleaf tree species.

  8. Influence of airborne pollen counts and length of pollen season of selected allergenic plants on the concentration of sIgE antibodies on the population of Bratislava, Slovakia

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    Jana Ščevková

    2015-09-01

    Full Text Available Introduction and objective. The association between airborne pollen counts or duration of pollen season and allergy symptoms is not always distinguished. The purpose of this study was to examine the correlation between pollen exposure (annual total pollen quantity and main pollen season length of selected allergenic plants in the atmosphere of Bratislava, and concentration of allergen-specific immunoglobulin E (sIgE in serum of patients with seasonal allergy during 2002–2003. Materials and methods. The concentration of pollen was monitored by a Burkard volumetric pollen trap. At the same time, 198 pollen allergic patients were testing to determine the values of sIgE antibodies against selected pollen allergens; a panel of 8 purified allergens was used. Results. The highest percentages of sensitization were detected for Poaceae and [i]Ambrosia[/i] pollen allergens. The most abundant airborne pollen types were Urticaceae, [i]Betula[/i], [i]Populus[/i], Fraxinus, Pinus and Poaceae. The length of the pollen season varied. The longest pollen season was that of the [i]Plantago[/i] – 105 days, and the shortest, [i]Corylus[/i] – 20 days. A significant correlation was found between annual total pollen quantity and median sIgE values, especially in 2002. Conclusions. A strong and significant positive correlation was observed between pollen counts, excluding [i]Betula[/i], and sIgE levels in both analysed years. The correlation was weaker and negative in the case of length of pollen season and sIgE values.

  9. THE WATER CONSERVATION OF THE MAJOR FOREST TYPES OF DAQING MOUNTAIN IN INNER MONGOLIA%内蒙古大青山主要林分类型水源涵养能力研究

    Institute of Scientific and Technical Information of China (English)

    王冬至; 张秋良; 陈高娃; 青梅

    2012-01-01

    In this paper, the canopy interception, water holding capacity of litter and soil moisture level was observed in natural pine forest and the different ages of secondary birch, and the observation data were analyzed by SAS data processing software. The regression equation of natural rainfall and canopy interception was established. The result shows that soil water holding capacity is increasing from the Pinus tabulaeformis plantation andyoung-aged forest、middle -aged forest、matured forest of Betula platyphylla natural secondary forest, but there is a downward trend as soil depth increased. Soil water holding capacity of Betula platyphylla natural secondary forest is higher than that of Pinus tabulaeformis plantation.%本文对研究区的油松人工林和天然白桦次生林不同林龄的林冠截留量、枯落物持水量及土壤层的持水量进行了观测,并通过SAS数据处理软件对观测数据进行了分析.建立了自然降雨与林冠截留的回归方程,不同分解程度枯落物持水比率及持水速率的表达式,并对不同林分类型土壤持水量进行多重比较分析,结果显示油松人工林和天然白桦次生林的幼龄林、中龄林、成熟林土壤持水量依次增大并随着土层深度的增大持水能力呈下降趋势,天然白桦次生林的土壤持水量高于人工油松林.

  10. 黑河地区不同优势树种林下枯落物量的比较%Comparing the Litter Amounts under Dominant Tree Species of Heihe District

    Institute of Scientific and Technical Information of China (English)

    孙元发; 吴铭

    2014-01-01

    枯落物是森林生态系统物质循环的一个重要组成部分,具有极为重要的水文功能,枯落物水文生态功能的发挥首先取决于枯落物的量。通过对黑河地区不同优势树种林下枯落量的调查与测定,结果表明:黑河地区各种优势树种中,落叶松的单位面积上枯落物总干质量最大,达到5.46 t 灋hm -2,而樟子松的单位面积上枯落物总干质量最小,只有1.08t 灋hm -2,赤杨、山杨、柞树、白桦、黑桦单位面积上枯落物总干质量为2.93~4.9t 灋hm -2。%Litter is an important constituent part in forestry ecosystem cycle ,with vital hydrological function ,which is determined primarily by litter amount .In this work ,litter amount under dominant tree species of Heihe district was surveyed .The result manifested litter amount of unit area was highest under Larix gmelinii ,up to 5 .46 t · hm -2 , while it was lowest under Pinus sylvestris ,only with 1 .08 t · hm -2 .Under A lnus japonica ,Populus davidiana , Quercus mongolica ,Betula platyphylla ,Betula dahurica ,it was from 2 .93 to 4 .9 t · hm -2 .

  11. Late Quaternary Stratigraphy, Glacial Limits, and Paleoenvironments of the Marresale Area, Western Yamal Peninsula, Russia

    Science.gov (United States)

    Forman, Steven L.; Ingólfsson, Ólafur; Gataullin, Valery; Manley, William; Lokrantz, Hanna

    2002-05-01

    Stratigraphic records from coastal cliff sections near the Marresale Station on the Yamal Peninsula, Russia, yield new insight on ice-sheet dynamics and paleoenvironments for northern Eurasia. Field studies identify nine informal stratigraphic units from oldest to youngest (the Marresale formation, Labsuyakha sand, Kara diamicton, Varjakha peat and silt, Oleny sand, Baidarata sand, Betula horizon, Nenets peat, and Chum sand) that show a single glaciation and a varied terrestrial environment during the late Pleistocene. The Kara diamicton reflects regional glaciation and is associated with glaciotectonic deformation from the southwest of the underlying Labsuyakha sand and Marresale formation. Finite radiocarbon and luminescence ages of ca. 35,000 to 45,000 yr from Varjakha peat and silt that immediately overlies Kara diamicton place the glaciation >40,000 yr ago. Eolian and fluvial deposition ensued with concomitant cryogenesis between ca. 35,000 and 12,000 cal yr B.P. associated with the Oleny and the Baidarata sands. There is no geomorphic or stratigraphic evidence of coverage or proximity of the Yamal Peninsula to a Late Weichselian ice sheet. The Nenets peat accumulated over the Baidarata sand during much of the past 10,000 yr, with local additions of the eolian Chum sand starting ca. 1000 yr ago. A prominent Betula horizon at the base of the Nenets peat contains rooted birch trees ca. 10,000 to 9000 cal yr old and indicates a >200-km shift northward of the treeline from the present limits, corresponding to a 2° to 4°C summer warming across northern Eurasia.

  12. PALYNOLOGICAL ASSEMBLAGES FROM THE BOREHOLE ZKA4 AT DAQIAO TOWN, JIANGDU CITY, JIANGSU PROVINCE AND THEIR ENVIRONMENTAL MEANINGS%江苏省江都市大桥镇ZKA4钻孔第四纪孢粉组合及其环境变化研究

    Institute of Scientific and Technical Information of China (English)

    张宗言; 于俊杰; 蒋仁; 韩芳; 柯学; 徐亚东; 何卫红

    2014-01-01

    本文依据江苏省江都市大桥镇第四系钻孔(ZKA4)中孢粉的分布,自下至上划分了11个孢粉组合:1.Betula-Ulmus-Artemisia,2.Ulmus-Chenopodiaceae-Quercus,3.ArtemisiaGramineae-Quercus,4.Liquidambar-Polypodiaceae-Ulmus,5.Pinus-Quercus-Betula-Juglans,6.Quercus-Juglans-Artemisia,7.Quercus-Polygonum-Juglans-Carya,8.Betula-Gramineae-Artemisia,9.Quercus-Polypodiaceae,10.Podocarpus-Triorites-Polypodiaceae,11.Pinus-Podocarpus-Juglans-Pterocarya.依据孢粉组合,识别出更新世以来七个气候冷暖变化阶段.孢粉组合1为常绿落叶针阔叶混交林,气候以冷干为主,向上气候回暖;孢粉组合2为高寒灌丛—落叶针阔叶混交林,以冷干为主;孢粉组合3为草本—落叶针阔叶混交林,较前一阶段气候变暖,偏暖干;孢粉组合4-5以落叶阔叶为主,整体上以变暖为主;孢粉组合6-7为落叶针阔叶混交林,整体气候为暖湿,早期略干;孢粉组合8-9为以针叶为主的针阔叶混交林,气候温凉偏湿;孢粉组合10-11为常绿落叶阔叶混交林,气候以湿暖为主.

  13. Late glacial multiproxy evidence of vegetation development and environmental change at Solova, southeastern Estonia

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    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.

  14. Study on complexity of plant communities at different altitudes on the Northern Slope of Changbai Mountain

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By the method of gradient pattern analysis, twenty plots were set at altitudes of 700-2600 m with an interval of 100 m on the northern slope of the Changbai Mountain. The dissimilarity of respective sub-plots in the same community was measured and the complexity of plant communities at different altitudes was analyzed. The result from binary data of tree species in canopy tree indicated that the sub-plots in the communities, except subalpine Betula ermanii forest, showed comparatively high dissimilarity in species composition. Especially, the dissimilarity index (0.7) of broadleaved/Korean pine forest at low altitudes was obviously higher than other communities. The differences are not obvious between communities referring to dark coniferous forest. Comparatively, the dissimilarity in sub-plots of the communities at altitude of 1400 m was slightly higher than that of other communities, which reflected the complexity of tree species compositions of transitory-type communities. For subalpine Betula ermanii forest, tree species composition was simple and showed a high similarity between sub-plots. The results derived from binary data of shrub showed that the dissimilarity index of shrub species in broadleaved/Korean pine forest at low altitudes was higher than that in other communities, but the divergence tendency wasn't so obvious as that of arbor species. The dissimilarity derived from binary data of herb and all plant species at different altitudes showed greatly close tendency, and the differences in herb and all plant species between sub-plots were the greatest for the communities of broad-leaved-Korean pine forest and alpine tundra zone.

  15. Free atmospheric CO2 enrichment increased above ground biomass but did not affect symbiotic N2-fixation and soil carbon dynamics in a mixed deciduous stand in Wales

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    A. R. Smith

    2011-02-01

    Full Text Available Through increases in net primary production (NPP, elevated CO2 is hypothesized to increase the amount of plant litter entering the soil. The fate of this extra carbon on the forest floor or in mineral soil is currently not clear. Moreover, increased rates of NPP can be maintained only if forests can escape nitrogen limitation. In a Free atmospheric CO2 Enrichment (FACE experiment near Bangor, Wales, 4 ambient and 4 elevated [CO2] plots were planted with patches of Betula pendula, Alnus glutinosa and Fagus sylvatica on a former arable field. After 4 years, biomass averaged for the 3 species was 5497 (se 270 g m−2 in ambient and 6450 (se 130 g m−2 in elevated [CO2] plots, a significant increase of 17% (P = 0.018. During that time, only a shallow L forest floor litter layer had formed due to intensive bioturbation. Total soil C and N contents increased irrespective of treatment and species as a result of afforestation. We could not detect an additional C sink in the soil, nor were soil C stabilization processes affected by elevated [CO2]. We observed a decrease of leaf N content in Betula and Alnus under elevated [CO2], while the soil C/N ratio decreased regardless of CO2 treatment. The ratio of N taken up from the soil and by N2-fixation in Alnus was not affected by elevated [CO2]. We infer that increased nitrogen use efficiency is the mechanism by which increased NPP is sustained under elevated [CO2] at this site.

  16. Vegetation composition and shrub extent on the Yukon coast, Canada, are strongly linked to ice-wedge polygon degradation

    Directory of Open Access Journals (Sweden)

    Juliane Wolter

    2016-06-01

    Full Text Available Changing environmental and geomorphological conditions are resulting in vegetation change in ice-wedge polygons in Arctic tundra. However, we do not yet know how microscale vegetation patterns relate to individual environmental and geomorphological parameters. This work aims at examining these relations in polygonal terrain. We analysed composition and cover of vascular plant taxa and surface height, active layer depth, soil temperature, carbon and nitrogen content, pH and electrical conductivity in four polygon mires located on the Yukon coast. We found that vascular plant species composition and cover correlates best with relative surface height. Ridges of low-centred polygons and raised centres of high-centred polygons support the growth of mesic and wetland species (e.g., Betula glandulosa, Salix pulchra, S. reticulata, Rubus chamaemorus, various ericaceous dwarf shrubs, Eriophorum vaginatum, Poa arctica. Wetland and aquatic plant species (e.g., E. angustifolium, Carex aquatilis, C. chordorrhiza, Pedicularis sudetica grow in low-lying centres of polygons and in troughs between polygons. We also found a relationship between vascular plant species composition and substrate characteristics such as pH, electrical conductivity and total organic carbon, although the individual influence of these parameters could not be determined because of their correlation with relative surface height. Our findings stress the regulatory role of microtopography and substrate in vegetation dynamics of polygonal terrain. Ongoing warming in this region will lead to changes to polygonal terrain through permafrost degradation and subsequent conversion of low-centred into high-centred polygons. Our results indicate that shrubs, particularly Betula glandulosa and heath species, have the potential to expand most.

  17. Plant Diversity and Its Elevational Gradient Patterns in Wulu Mountain, Shanxi, China%山西五鹿山植物物种多样性及其海拔梯度格局

    Institute of Scientific and Technical Information of China (English)

    曲波; 苗艳明; 张钦弟; 毕润成

    2012-01-01

    Samplings were gathered and examined in forests along altitudinal gradients of Wulu Mountain, China. The results indicated that the major communities in the forests can be classified as Quercus wutaishanica, Pinus labulaeformis, Acer ginnala, Betula platyphylla, Pinus bungeana, Syringa reticulate- Acer ginnala and Betula platyphylla community. Our research suggests that the Quercus wutaishanica community appears to be a dominant community in a successional stage toward temperate deciduous broad-leaved forests. The species richness in different layers of these communities can be distinguished as, herb layer > shrub layer > tree layer. Both the Shannon-Wiener diversity index and Simpson diversity index showed similar patterns. The species diversity indices of different layers and overall importance value of the forest communities indicate that the forests appear to be successional and sub-climax communities in Wulu Mountain. Our research also suggests that there is a peak with higher species diversity index in the communities of middle elevation. We suggested that the pattern could be affected by temperature, moisture , and human disturbance. The pattern could also be influenced by the nature of successional stages and sub-climax communities.%采用典型取样法,沿海拔梯度对五鹿山自然植被进行调查.结果表明:五鹿山主要群落类型为辽东栎(Quercus wutaishanica)群落、油松(Pinus tabulaeformis)群落、茶条槭(Acer ginnala)群落、白皮松(Pinus bungeana)群落、暴马丁香-茶条槭(Syringa reticulate-Acer ginnala)群落和白桦(Betula platyphylla)群落.其中,辽东栎群落略占优势,这可能暗示着该地区植被具有继续向暖温带落叶阔叶林演替的倾向.各层次植物物种丰富度呈现出草本层>灌木层>乔木层特征,Shannon-Wiener多样性指数和Simpson多样性指数整体规律为草本层>灌木层>乔木层.以五鹿山森林群落不同层次的各种物种多样性指数和森林

  18. 高原湿地纳帕海周边山地不同植被类型枯落物持水特性%Water Holding Characteristics of Litters of Different Species in Mountainous Area of Napahai Plateau Wetland

    Institute of Scientific and Technical Information of China (English)

    陆梅; 田昆; 赖建东; 赵一鹤; 魏江舟

    2011-01-01

    The water holding capacity was characterized for the litters from eight plantation types in the mountainous area of Napahai Plateau Wetland. The results show that, for all the eight plantation types, the semi-decomposed and decomposed layer had higher litter storage and water reserving capacity than the freshly-littered layer. The litter storage decreased from highwood, shrub to waste grassland. Specifically, the litter storages of natural Picea asperata Mast, mixed forest of Pinus densata Mast and Rhododendron simsii Planch, mixed forest of Salix cupularis Rehd and Betula platyphylla Suk, Crataegus pinnatifida Bge and waste grassland demonstrated a capacity of 36.60, 30.67, 26.63, 25.61 and 5. 30 t/hm2 , respectively. Comparatively, mixed forest of Salix cupularis Rehd and Betula platyphylla Suk had the highest water holding capacity, and seriously human-disturbed Pinus densata Mast had the lowest. The water holding capacity of the litters increased rapidly during the initial first hour, and then slightly increased after 6~10 hour saturation. The highest water absorption rates were observed in the first 30 minute saturation time, and thereafter the rates decreased substantially. Water loss rates were similar for all the litters, showing a linear decreasing trend. Systematic analysis indicated that the litter of mixed forest of Salix cupularis Rehd and Betula platyphylla Suk had the highest water holding capacity, the strongest flood-adjusting capacity, the most ideal water loss process and the highest water supply capacity, and the best hydro-ecological effect among the eight plantation types.%对高原湿地纳帕海周边山地8种不同植被类型枯落物持水特性进行了研究.结果表明,(1)8种植被类型枯落物储量和总持水量均表现出半分解+分解层>未分解层的变化趋势;枯落物储量呈现从乔木林到灌木林和荒草地逐渐降低的总体趋势;高山柳+白桦混交林最大总持水量最大,受人为干扰较为

  19. 1983-2003年浑善达克沙地中部沙丘植被在放牧条件下的比较%Vegetation Change in Response to Continuous Grazing in the Center of Hunshandak Sandland During the Period of 1983 -2003

    Institute of Scientific and Technical Information of China (English)

    彭羽; 薛达元; 牛书丽; 刘美珍; 李永庚; 蒋高明

    2011-01-01

    为了研究长期放牧条件下植被的变化,采用样方调查方法分析了1983-2003年浑善达克沙地中部的沙丘植被在放牧条件下的变化.期间,物种多样性、生物量和盖度在第1个10年缓慢下降,而第2个10年则加速下降,在沙丘阳坡形成了以适口性差的一年生草本植物为主的稀疏植被,阴坡以木本树木为主.且表现为木本植物的降低速度比草本植物慢.1983年,沙丘阳坡植物以褐沙蒿(Artemisia intramongolica)、展枝唐松草(Thalictrum squarrosum)、叉分蓼(Polygonum davaricatum)为主;阴坡植物以白榆(Ulmus pumila)、圆叶桦(Betula rotundifolia)、糙隐子草(Cleistogenes squarrosa)为主.而到了2003年,沙丘阳坡植被主要为褐沙蒿、雾冰藜(Bassia dasyphylla)、虫实(Corispermum heptapotamicum);阴坡植被主要为稠李(Prunus padus)、柴桦(Betulafruticosa)、耧斗叶绣线菊(Spiraea aquilegifolia)等.分析表明,20年间植被变化主要是由放牧造成的,气候变化并非主因.20年来,牛羊数量剧增,超过了草原承载力,而气温和降水则没有明显变化.%The vegetation changes in response to continuous grazing in the center of Hunshandak Sandland, northern China during the period of 1983 -2003 was investigated in field. Results indicated that species diversity, biomass and coverage decreased slowly in the first 10-year period and decreased quickly in the second 10-year period, and woody plant declined more slowly than herbaceous plant. The vegetation type mainly consisted of a sparse cover of unpalatable annual grass and shrubs on the sunny slope, and woody trees on the shady slope of sandy dune. The vegetation was dominated by Artemisia intramongolica, Thalictrum squarrosum, Polygonum davaricatum on the sunny slope and by Ulmus pumila, Betula rotundifolia, Cleistogenes squarrosa on the shady slope of sandy dune in 1983. However, the dominant species were replaced by Artemisia intramongolica, Bassia dasyphylla, Corispermum

  20. Airborne pollen spectrum of Dnіpropetrovsk city as a basis of hay fever control

    Directory of Open Access Journals (Sweden)

    V. V. Rodinkova

    2013-02-01

    other representatives of Asteraceae constituted of 5% each. The most abundant tree pollen rain (4% from total annual count was produced by the Populus species. Betula pollen was the next having up 2% of annual pollen rain in Dnipropetrovsk. As can be seen, the first arboreal spring-summer pollination wave was not massive in Dnipropetrovsk. It was represented by Populus, Betula, Acer, Fraxinus, Quercus, Ulmus, Pinus, Juglans pollen spread in the end of March, whole April and the first weeks of May mostly. However, the second wave was intensively seen from the mid of July till the mid of October. Important airborne pollen producing taxa were Artemisisia, Ambrosia, Asteraceae, Chenopodiaceae, Urtica, Plantago, Polygonaceae pollen at that time. Important airborne pollen allergens of Poaceae family (grasses held the 7th position in the total annual pollen rain and were recorded between two pollination waves from the mid of May till the end of June mostly. The worst period for the patients was associated with the Betula, Acer and Quercus pollination from 13th of April  till the mid of May and with Ambrosia and Artemisia pollination from 28th of July, till September, 30. The present airborne pollen calendar should be considered while diagnosing the hay fever symptoms in sensitive patients. It’s important to continue the pollen count and control in Dnіpropetrovsk due to constant changing of climatic and anthropogenic conditions impacting the pollen production and release.

  1. 百花山典型林分土壤有机碳储量及垂直分布特征%Soil Organic Carbon Storage and Vertical Distribution of Different Forest Types in Baihua Mountain Area

    Institute of Scientific and Technical Information of China (English)

    刘艳; 查同刚; 付汝军

    2012-01-01

    针对百花山落叶阔叶混交林、华北落叶松林、桦木林3种典型林分土壤有机碳储量及垂直分布特征进行研究.结果表明,不同林分类型下的土壤有机碳含量存在明显差异,桦木林最高(33.87g/kg±2.82g/kg),华北落叶松林次之(27.42 g/kg±2.21 g/kg),落叶阔叶混交林最低(26.24 g/kg±1.91 g/kg),桦木林土壤有机碳的密度为(26.06±1.88) kg/m2,落叶阔叶混交林为(19.81±1.70) kg/m2,华北落叶松林为(18.94±1.50)kg/m2,土层间有机碳密度为(1.57~7.22) kg/m2,且随着土层深度的增加呈现减少的趋势;不同林分中0~20 cm土层有机碳储量占整个剖面有机碳总储量的百分比均达到50%以上,0~20 cm土层有机碳含量变化总趋势为下坡位>中坡位>上坡位.%Storage and vertical distribution features of soil organic carbon (SOC) about mixed deciduous broad-leaved forest,Larix principis-rupprechtii forest and Betula spp. Forest in Baihua Mountain of Beijing were studied in this paper. The results were as follows: the contents of SOC in different types of forest showed significantly difference; SOC content presented a rule as Betula spp. Forest> Larix principis-rupprechtii forest > mixed deciduous broad-leaved forest, the average value was (33.87±2.82) g/kg, (27.42 + 2.21) g/kg, and (26.24 + 1.91) g/kg correspondenly; SOC density was Betula spp. Forest (26.06±l. 88 kg/m2) > mixed deciduous broad-leaved forest (19. 81 ±1. 70 kg/m2) >Larix principis-rupprechtii forest (18. 94 + 1. 50 kg/m2). SOC density changed with a range of 1. 57~7. 22 kg/m2 for five soil layers in the three forest types, and both the density and content decreased with the depth of soil layers; on the upper layer (0 - 20 cm), the SOC content followed the variety trend of lower slope > middle slope >upper slope, and this layer occupied more than 50% SOC in all the soil profiles (0 - 80 cm).

  2. CUTICULAR STRUCTURE OF TWO ANGIOSPERM FOSSILS IN NEOGENE FROM TENGCHONG, YUNNAN PROVINCE AND ITS PALAEOENVIRONMENTAL SIGNIFICANCE%云南腾冲新近纪两种被子植物化石的角质层构造及其古环境意义

    Institute of Scientific and Technical Information of China (English)

    孙柏年; 丛培允; 阎德飞; 解三平

    2003-01-01

    This paper emphatically describes the cuticular characteristics of two fossil angiosperm species Betula mioluminifera Hu et Chaney and Carpinus subcordata Nathorst collected from Neogene in Tengchong, Yunnan. The cuticular characteristics of their Nearest Living Relative species (NLR species), Betula luminifera Winkler and Carpinus cordata B1.var. mollis Cheng et Chen, are analysed. In this experiment, we have got the lower epidermis of C.subcordata, whose characteristics are described as follows: Only the middle and lower parts of leave preserved; length about 7.5 cm, width 5 cm. Midrib strong; angle between ventricumbent and midrib 40°-50°; nearer to the base, bigger the angle; venulose, more than 12 pairs. Upper epidermis a little thicker and net-veined, stomata not found; epidermic cells arrayed rotundly, polygonal, length and width 20-30 μm; length of the net about 350 μm, width about 200 μm; width of nervecourses 50 μm with 3-4 rows of parallel cells; cells in nervecourses oblong, length about 2-3 times of width. Lower epidermis thin with stomata; trichome found; arrangement of epidermic cells as the same of upper epidermis. Distribution of stomata ruleless; type of stomatal apparatus Anomocytic; stomata slightly sunken; guard cells kidney-shaped and slightly lower than surrounding cells; inner surface of guard cells thick; guard cell surrounded by several epidermic cells. The cuticle, with its stomatal pores, represents the interface between plants and atmosphere, and its features such as cuticle thickness, stomatal density (SD), stomatal index (SI) and stomatal ratio (SR) are well used as a palaeoenvironmental indicator. Therefore, we can analyse changes in palaeoenvironment by studying the stomatal parameter of fossil plants which are sensitive to the change in atmospheric CO2 concentration. In this experiment, we have got the stomatal parameter of C.subcordata which indicates that atmospheric CO2 concentration in Neogene was higher than that of

  3. Influence of aerogenic contamination on phytoncide activity of woody plants

    Directory of Open Access Journals (Sweden)

    S. O. Volodarez

    2015-07-01

    Full Text Available The main objective of this paper is to determine variations of antimicrobial activity of the volatile organic compounds from leaves of woody plants, which are growing on the areas with the different air pollution degree in the south-east of Ukraine. The research objects were Aesculus hippocastanum L., Betula pendula Roth, Salix alba L., Picea pungens Engelm. in Donetsk, Ukraine, and 6 species (Betula pendula Roth, Fraxinus excelsior L., Robinia pseudoacacia L., Populus nigra L., Tilia cordata Mill., Picea pungens Engelm. in Kramatorsk, Ukraine. Samples were collected in Donetsk every month during 2012 and 2013 years on four sample areas. Three research areas border with Donetsk Metallurgical Plant PSC, heavy traffic road and Kalinin coal mine, that feature such pollutants as CO2, SO2, NO2, and marsh gas. The fourth research area is the recreation zone (Donetsk Culture and Leisure Park near Donbass Arena stadium. The control area is located in the Donetsk Botanical Garden. The leaves from trees in Kramatorsk were collected in July and August 2013 on the sample area. The research area borders with Novokramatorsk Machine-building Plant JSC, which also features CO2, SO2, NO2 and other pollutants. The control area is located in the Jubilejnyi park. The research proves that antimicrobial activity of the volatile organic compounds from leaves of species under studyis sensitive to the impact of pollutants. Moreover, the antimicrobial activity of leaves B. pendula, S. alba, F. excelsior, R. pseudoacacia, P. nigra increases under the influence of pollutants from metallurgical plants and traffic exhausts. The antimicrobial ability of A. hippocastanum, T. cordata and P. pungens enhances in the areas with the cleaner air. These species are not gas-resistant species. Consequently, gas-resistant species feature the higher antimicrobial activity in the conditions of contamination. The other benefit of this study consists in monitoring of the seasonal

  4. 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.

  5. 实验室不同温度下添加细根(草根)对土壤活性有机碳的影响%Effect of Fine Root ( Grass Root) Added to Soil on Soil Active Qrganic Carbon Under Different Temperature Condition in the Laboratory Microcosm

    Institute of Scientific and Technical Information of China (English)

    冯发堂; 荣丽; 李贤伟; 赖元长; 周义贵; 范川

    2011-01-01

    In this study, the effects of fine root (grass root ) decomposition to the soil active organic carbon were investigated in a laboratory microcosm under 10, 20 and 30 ℃.The roots were mixed with the soil in the following four treatments: mixture of birch ( Betula luminifera) roots and grass ( Hemarthria compressa) roots ( treatment 1 ), birch ( Betula luminifera) roots ( treatment 2), grass ( Hemarthria compressa) roots ( treatment 3 ) , cedar ( Crytomeria fortunei)roots (treatment 4) and no roots (CK).The results showed that fine root source, incubation time and incubation temperature all influenced soil microbial biomass carbon (SMBC) ,water soluble organic carbon (WSOC) , readily oxidized carbon (ROC) ,total organic carbon (TOC).After 120 d, the contents of SMBC, WSOC, ROC ,and TOC in the treatments were higher than those in CK (P < 0.05 ).The contents of SMBC ,WSOC, ROC ,and TOC in treatment 1 were higher than those in the other treatments in 60 or 120 d.The effect of incubation temperature on MBC and WSOC in four treatments was ranked in an order as the following, 30 ℃ >20 ℃ > 10 ℃ , while the effect on ROC and TOC was in an order of 10 ℃ >20 ℃ >30 ℃ (P<0.05).%研究不同温度(10,20和30℃条件下分别向土壤中添加光皮桦细根(直径<2 mm)与扁穗牛鞭草草根棍合物(处理1)、光皮桦细根(处理2)、扁穗牛鞭草草根(处理3)和柳杉细根(处理4)这4种处理对土壤活性有机碳的影响.结果表明:添加细根的种类、培养温度和培养时间均对土壤微生物量碳、水溶性有机碳、易氧化有机碳和总有机碳含量产生影响;120天后各处理的土壤微生物量碳、水溶性有机碳、易氧化有机碳和总有机碳含量都显著大于对照(P20℃>10℃,对易氧化有机碳和总有机碳含量的影响表现为10℃>20℃>30℃(P<0.05).

  6. Botanical Verification of Divine Trees in “Legend of Mountains and Rivers”%《山海经》三大神木的植物学考订

    Institute of Scientific and Technical Information of China (English)

    刘本玺; 李恒; 龙春林; 裴盛基; 李尚雨; 李晓明

    2013-01-01

    《山海经》中有太阳东出扶桑、日中建木、西归若木的传说,长期以来一直存疑,争论不休,直到四川广汉三星堆遗址出土了青铜神树,才证明了传说的真实性.我们结合《山海经》等相关典籍,从植物学角度对扶桑、建木、若木的原植物进行探讨,基于典籍描述、考古资料、植物形态特征、生态习性和地理分布等,初步考订扶桑的植物原型为桦木科白桦(Betula platyphylla),建木的植物原型为杉科杉木(Cunninghamia lanceolata),若木的植物原型为木棉科木棉(Bombax ceiba).%There is a tale in the Chinese ancient book “Legend of Mountains and Rivers” where the sun rises from a “Fusang Tree” in the east,hangs above a “Jian Tree” at noon,and goes down at the “Ruo Tree” in the west.People have debated the reality of such Divine Trees for many centuries and arguments for and against their existence did not stop until Bronze Trees were discovered in Sanxingdui,Guanghan Prefecture,Sichuan Province.This archaeological discovery proved that Divine Trees referred to in folklore existed.Here we report verification of prototypes of the three Divine Trees referred to in “Legend of Mountains and Rivers”,based on botanical knowledge and reference to the ancient literature.We verified that the Fusang Treeg Tprototype may have been Betula platyphylla,the Jian Tree's prototype was possibly Cunninghamia lanceolata,while the Ruo Tree's prototype may have been Bombax ceiba.

  7. Osmolality and Non-Structural Carbohydrate Composition in the Secondary Phloem of Trees across a Latitudinal Gradient in Europe.

    Science.gov (United States)

    Lintunen, Anna; Paljakka, Teemu; Jyske, Tuula; Peltoniemi, Mikko; Sterck, Frank; von Arx, Georg; Cochard, Hervé; Copini, Paul; Caldeira, Maria C; Delzon, Sylvain; Gebauer, Roman; Grönlund, Leila; Kiorapostolou, Natasa; Lechthaler, Silvia; Lobo-do-Vale, Raquel; Peters, Richard L; Petit, Giai; Prendin, Angela L; Salmon, Yann; Steppe, Kathy; Urban, Josef; Roig Juan, Sílvia; Robert, Elisabeth M R; Hölttä, Teemu

    2016-01-01

    Phloem osmolality and its components are involved in basic cell metabolism, cell growth, and in various physiological processes including the ability of living cells to withstand drought and frost. Osmolality and sugar composition responses to environmental stresses have been extensively studied for leaves, but less for the secondary phloem of plant stems and branches. Leaf osmotic concentration and the share of pinitol and raffinose among soluble sugars increase with increasing drought or cold stress, and osmotic concentration is adjusted with osmoregulation. We hypothesize that similar responses occur in the secondary phloem of branches. We collected living bark samples from branches of adult Pinus sylvestris, Picea abies, Betula pendula and Populus tremula trees across Europe, from boreal Northern Finland to Mediterranean Portugal. In all studied species, the observed variation in phloem osmolality was mainly driven by variation in phloem water content, while tissue solute content was rather constant across regions. Osmoregulation, in which osmolality is controlled by variable tissue solute content, was stronger for Betula and Populus in comparison to the evergreen conifers. Osmolality was lowest in mid-latitude region, and from there increased by 37% toward northern Europe and 38% toward southern Europe due to low phloem water content in these regions. The ratio of raffinose to all soluble sugars was negligible at mid-latitudes and increased toward north and south, reflecting its role in cold and drought tolerance. For pinitol, another sugar known for contributing to stress tolerance, no such latitudinal pattern was observed. The proportion of sucrose was remarkably low and that of hexoses (i.e., glucose and fructose) high at mid-latitudes. The ratio of starch to all non-structural carbohydrates increased toward the northern latitudes in agreement with the build-up of osmotically inactive C reservoir that can be converted into soluble sugars during winter

  8. Does Tree Architectural Complexity Influence the Accuracy of Wood Volume Estimates of Single Young Trees by Terrestrial Laser Scanning?

    Directory of Open Access Journals (Sweden)

    Carsten Hess

    2015-10-01

    Full Text Available Accurate estimates of the wood volume or biomass of individual trees have gained considerable importance in recent years. The accuracy of wood volume estimation by terrestrial laser scanning (TLS point cloud data may differ between individual trees due to species-specific differences in tree architecture. We selected three common and ecologically important central European deciduous tree species, which differ considerably in tree architectural complexity in early ontogenetic stages: Acer pseudoplatanus (simple, Sorbus aucuparia (intermediate and Betula pendula (complex. We scanned six single young trees for each species (18 trees in total under optimal scan conditions (single tree stand, leafless state, four scanning positions, high resolution. TLS-based volume estimates were derived for the total tree as well as for the two compartments; trunk and branches, using a voxel-based bounding box method. These estimates were compared with highly accurate xyolmetric (water displacement volume measurements. Coefficients of determination between xylometric measurements and bounding box estimates were very high for total trees (R2adj = 0.99, trunks (R2adj = 0.99, and high for branches (R2adj = 0.78. The accuracy of estimations for total tree and trunk volume was highly similar among the three tree species. In contrast, significant differences were found for branch volume estimates: the accuracy was very high for Sorbus aucuparia, intermediate for Betula pendula, and low for Acer pseudoplatanus. A stepwise multiple regression showed that the accuracy of branch volume estimates was negatively related to the number of the first-order branches within diameter sizes of D ≤ 5 mm and crown surface area (R2adj = 0.61. We conclude that the accuracy in total tree and trunk volume estimates was not affected by the studied types of tree architectural complexity. The impact of the structural variability of branches and occlusion by branches was, thus, not as high as

  9. High-Resolution Remote Sensing and Stable Isotope Patterns Across Heath-Shrub-Forest Ecotone at Abisko and Vassijaure, Northern Sweden

    Science.gov (United States)

    Schwan, M. R.; Herrick, C.; Hobbie, E. A.; Chen, J.; Varner, R. K.; Palace, M. W.; Marek, E.; Kashi, N. N.; Smith, S. L.

    2015-12-01

    Rapid warming in arctic and sub-arctic environments shifts plant community structure which in turn can alter carbon cycling by releasing large stocks of carbon sequestered in arctic soils. Much work has been done in sub-arctic peatlands to understand how shifts in dominant vegetation cover can ultimately affect global carbon balances, but less focus has been given to upland environments where similar changes are occurring. Recent circumpolar expansion of deciduous shrubs and trees in sub-arctic upland environments may alter carbon cycling due to shrubs and trees sequestering less C in soils than the heath plants they typically replace. In this study we explored the relationship between nutrient and carbon cycling and above-ground vegetation on six transects which traverse an ecotone gradient from heath tundra (dominated by ericoid mycorrhizal plants) through deciduous shrubs to deciduous trees (dominated by ectomycorrhizal plants) in upland environments of sub-arctic Sweden near Vassijaure (~850 mm precipitation) and Abisko (~300 mm precipitation). We collected soil and foliage for analysis of natural abundances of stable carbon and nitrogen isotopes (δ13C and δ15N), which can be a sensitive indicator of C and N dynamics. We also took high-resolution remote aerial imagery over the transects to calculate percent cover of vegetation types using GIS software. We concurrently estimated percent cover in smaller plots on the ground of three dominant species, Empetrum nigrum, Betula nana, and Betula pubescens, to serve as ground-truthing for the aerial imagery. Analysis of vegetation cover data shows significant differences in vegetation types along the transects. Preliminary multiple regression analysis of isotopes shows that δ13C in organic soil at the Vassijaure site is mostly controlled by distance along the transect, an interaction term between transect distance and soil depth, and δ15N (adjusted r2 = 0.85, p < 0.0001). Values of δ13C were lower in soils in the

  10. Microbial Diversity of Primary Korean Pine Forests and Artificial Forests in Liangshui National Natural Reserve%凉水自然保护区原始红松林与人工林土壤微生物多样性

    Institute of Scientific and Technical Information of China (English)

    郭彦萃; 熊毅; 张志

    2013-01-01

    采用BIOLOG微平板法,研究了小兴安岭凉水国家自然保护区内原始红皮云杉( Picea koraiensis Na-kai)红松林、青楷槭( Acer tegmentosum Maxim.)红松林与人工兴安落叶松( Larix gmelini Rupr.)林、白桦( Betula platyphylla Suk.)林土壤微生物多样性特征。结果表明:各林型土壤微生物AWCD值随土层深度与季节变化表现为,在表层与0~10 cm土层中,四季2种原始红松林均高于人工林;在>10~20 cm土层中以人工林在春、夏、秋三季最高,冬季仍以原始红松林最高。不同土层的3种微生物多样性指数均以青楷槭红松林最高,且显著高于2种人工林。可见,原始阔叶红松林土壤微生物比原始针叶红松林及人工林土壤微生物具有更丰富的多样性。%By BIOLOG microplate method, an investigation was conducted to study the soil microbial diversity characteristics of Picea.koraiensis Nakai, Acer tegmentosum Maxim, artificial Larix.gmelini Rupr.and Betula platyphylla Suk.in Liang-shui National Nature Reserve, Xiaoxing’an Mountain.The soil microbial AWCD values of the forest-type varied with soil depth and seasons:in the surface and 0-10 cm layer of soil, it was highest in two original Korean pine forest throughout the year;in the 10-20 cm layer of soil, it was highest in plantation in spring, summer and autumn, while it was highest in the primitive Korean pine forest in winter;three different soil microbial diversity indexes of all soil layers were highest in Acer tegmentosum Maxim forest, and significantly higher than those of two plantation.Therefore, the soil microbial diversi-ty of original Broad-leaved Korean Pine forest is richer than that of the original coniferous Korean pine forest and planta-tion.

  11. Preparation of Total DNA from "Recalcitrant Plant Taxa"%顽拗植物类群的总DNA制备

    Institute of Scientific and Technical Information of China (English)

    曾杰; 邹喻苹; 白嘉雨; 郑海水

    2002-01-01

    Contamination problems on DNA isolation from "recalcitrant plant taxa" which is rich in polysaccharides have been commonly encountered in a wide range of research fields such as plant population biology,biodiversity,and molecular marker-assisted breeding.Here we present an improved protocol to extract DNA efficiently from dry or fresh leaves of a "recalcitrant plant taxa",Betula alnoides Buch.Ham.ex D.Don in which three key steps are involved:1) washing out most of polysaccharides and other secondary compounds with CTAB-free buffer from homogenate; 2) adoption of 3% CTAB rather than 2% CTAB in the exaction medium; and 3) using of high concentration of salt prior to DNA precipitation with isopropanol to remove residual polysaccharides.The isolated DNA has been proved suitable for RAPD-PCR amplification and restriction digestion.This modified procedure is simple,inexpensive and reliable,and is also applicable to many other plant taxa with high polysaccharides.%从富含多糖的顽拗植物类群提取与纯化DNA是许多研究领域例如居群生物学、生物多样性、分子标记辅助育种研究普遍遇到的难题.以西南桦( Betula alnoides )为例发展了一套改进的方案,有效地从这种顽拗植物的干叶和鲜叶中制备了DNA.此方案包括3个关键步骤:首先从植物细胞匀浆中用不含CTAB的缓冲液洗去大部分多糖和其他次生物质;在提取介质中采用3% CTAB而不是通常用的2% CTAB;将常用的高盐去糖的纯化操作提前到用异丙醇沉淀DNA之前进行.从西南桦提取的DNA已成功地用于RAPD-PCR扩增和限制性酶切.这个简单、经济和可靠的改进方案也适用于许多其他的顽拗植物类群.

  12. Holocene environmental changes in southern Kamchatka, Far Eastern Russia, inferred from a pollen and testate amoebae peat succession record

    Science.gov (United States)

    Klimaschewski, A.; Barnekow, L.; Bennett, K. D.; Andreev, A. A.; Andrén, E.; Bobrov, A. A.; Hammarlund, D.

    2015-11-01

    High resolution palaeoenvironmental records in Far-Eastern Russia are rare, and the Kamchatka Peninsula is among the least studied areas of the region. This paper describes a record spanning the last ca. 11,000 yr, obtained from a bog in the southern part of Kamchatka. The radiocarbon dated core was analysed for pollen, testate amoebae, charcoal and loss-on-ignition (LOI). The vegetation during the early Holocene was dominated by grasses (Poaceae), birch (Betula) and heath (Ericaceae p. p.). Around 10,300 cal yr BP there was a substantial change in the vegetation cover to shrub alder (Alnus viridis s.l.) stands with sedges and ferns (Polypodiophyta) as well as herbs such as meadow rue (Thalictrum) in the understory. In the surroundings of Utka peatlands started to form. The variations in the vegetation cover were most probably caused by climatic changes. At the beginning of sediment accumulation, before 10,300 cal yr BP, the composition of the vegetation points to cooler summers and/or decreased annual precipitation. Around 10,300 cal yr BP, changes in vegetation occurred due to rising temperatures and/or changed water regimes. Increased abundancies of dry indicating testate amoebae after 9100 cal yr BP point to intermediate to dry soil conditions. Between 8600 and 7700 cal yr BP tree alder (Alnus incana) was widely spread at the site which probably indicates optimal environmental conditions. The tephra layer at 381-384.5 cm (ca. 8500 cal yr BP) produces a strong impact on the testate amoebae assemblages. At 7700 cal yr BP there was a sudden drop of A. incana in the local vegetation. From this time on, A. incana and also A. viridis decrease continuously whereas Betula gradually increases. The upper part of the sequence (after 6300 cal yr BP) shows higher abundancies of meadowsweet (Filipendula) and sweet gale (Myrica) pollen. After 6300 cal yr BP, changes in testate amoebae demonstrate variable soil moisture conditions at the site. Between 3700 and 1800 cal yr BP

  13. 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

  14. Germanium and Rare Earth Element accumulation in woody bioenergy crops

    Science.gov (United States)

    Hentschel, Werner

    2016-04-01

    Germanium and REEs are strategic elements that are used for high tech devices and engineered systems, however these elements are hardly concentrated into mineable ore deposits. Since these elements occur widely dispersed in the earth crust with concentrations of several mgṡkg-1 (Ge 1.6 mgṡkg-1, Nd 25 mgṡkg-1) a new possibility to gain these elements could be phytomining, a technique that uses plants to extract elements from soils via their roots. Since knowledge about accumulating plant species is quite limited we conducted research on the concentrations of strategic elements in wood and leaves of fast growing tree species (Salix spec., Populus spec., Betula pendula, Alnus glutinosa, Fraxinus excelsior, Acer pseudoplatanus). In total 35 study sites were selected in the mining affected area around Freiberg (Saxony, Germany), differing in their species composition and degree of contamination with toxic trace metals (Pb, As, Cd). On each site plant tissues (wood and leaves, respectively) of different species were sampled. In addition soil samples were taken from a soil depth of 0 - 30 cm and 30 - 60 cm. The aim of our work was to investigate correlations between the concentrations of the target elements in plant tissues and soil characteristics like pH, texture, nutrients and concentrations in six operationally defined soil fractions (mobile, acid soluble, oxidizable, amorphic oxides, crystalline oxides, residual or siliceous). Concentrations of elements in soil extracts and plant tissues were measured with ICP-MS. The element Nd was selected as representative for the group of REEs, since this element showed a high correlation with the concentrations of the other REE We found that the concentration of Nd in the leaves (0.31 mgṡkg-1Nd) were several times higher than in herbaceous species (0.05 mgṡkg-1 Nd). The concentration of Ge in leaves were ten times lower than that of Nd whereas in herbaceous species Nd and Ge were in equal magnitude. Within the tree

  15. Late Miocene (Pannonian) Vegetation from the Northern Part of Central Paratethys

    Science.gov (United States)

    Kováčová, M.; Doláková, N.

    2009-04-01

    During Late Miocene, the Western Carpathian paleogeography started to change. The Lake Pannon retreated southwards, and the northern coast of the back arc basin was slightly elevated due to progradation of deltaic and alluvial facies, especially in the lowlands. The studied „Pannonian lake" sediments come from the Czech and Slovak parts of Central Paratethys. Changes of the sedimentary environment from deep to shallow lake and deltaic environment, followed by development of alluvial plains were noticed. Salinity crisis due to Paratethys isolation led to development of total freshwater environment to the end of this period. Samples from 3 surficial localities and 15 boreholes were palynologically studied. Occasional occurences of Dinoflagellates indicate a slightly higher salinity, whereas green algae Pediastrum, aquatic ferns Azolla, and aquatic and coastal plants (Nelumbo, Nymphaea, Myriophyllum, Sparganium, Potamogeton, Cyperaceae etc.) represent a freshwater environment. Due to paleogeographic changes and climatic oscillations the number of thermophilous taxa decreased and some of them disappeared completely from this area (f. e. Sapotaceae, Palmae). Mostly broad-leaved deciduous elements of mixed mesophytic forests (Quercus, Celtis, Carya, Tilia, Carpinus, Betula, Juglans) with some thermophilous elements admixture of Engelhardia, Castanea, Trigonobalanopsis, Symplocos, Cornaceaepollis satzveyensis generally dominate. Variously high relief of the uplifted mountainy chains created ideal conditions for higher presence of extrazonal vegetation (Cedrus, Tsuga, Picea, Cathaya) in the investigated area. Zonal type of vegetation including marshes, riparian forests with Alnus, Salix, Pterocarya, Liquidambar, Betula, Fraxinus, shrubs and lianas on dryer substrates associated riparian forest (Buxus, Ericaceae, Vitaceae, Lonicera, Rosaceae type Rubus), and coastal swamps with Taxodiaceae, Nyssa, Myrica, Sciadopitys were growing in the floodplain lowlands of Vienna Basin

  16. Quantitative relationship between pollen and vegetation in northern China

    Institute of Scientific and Technical Information of China (English)

    XU QingHai; LI YueCong; YANG XiaoLan; ZHENG ZhenHua

    2007-01-01

    205 surface pollen samples from different communities in Northern China were analyzed to understand the quantitative relationship between pollen and its original vegetation. Pollen analysis and vegetation investigation show that the pollen assemblages differ a lot in different vegetation regions. Arboreal pollen account for more than 30%in temperate broad-deciduous forests region. In temperate steppe regions, herb pollen percentages are more than 90%,where Artemisia and Chenopodiaceae are dominant pollen types with Artemisia percentages more than 30%.In temperate desert, Chenopodiaceae pollen percentages are more than Artemisia, where ferns are rare. Cyperaceae pollen percentages are more than 20% in sub-alpine or cold meadows. The relations between pollen percentages and vegetation cover indicate that most arboreal pollen shows a close relationship with parent plant covers, most shrubby pollen types have more or less correlations, but most herbs do not show clear correlations. For arboreal pollen types, Picea pollen shows the closest correlation with spruce trees coverage, then is Quercus and Carpinus. Betula, Larix and Juglans have also high correlation coefficients with their plants coverage, but Betula pollen is of overrepresented pollen type and more than 40% in birch forest, while Larix and Juglans pollen is underrepresented and pollen percentages are more than 10%in Larix or Juglans pure forests. Pinus is of overrepresented pollen type, and pollen percentages have some relations with plants cover. Pine forest might present when Pinus pollen percentages are more than 30%.The relations between Ulmus and Populus pollen percentages and vegetation cover are not close, where they are mixed with other arbors. They cannot be recorded easily, but if their pollen percentages are more than 1%,Uimus or Populus trees should exist. For shrubby pollen types, the correlation between Vitex pollen percentages and vegetation cover is the highest, then is Corylus, Tamariaceae

  17. A 22 570 yr record of vegetational and climatic change from Wenhai Lake in the Hengduan Mountains biodiversity hotspot, Yunnan, Southwest China

    Science.gov (United States)

    Yao, Y. F.; Song, X. Y.; Wortley, A. H.; Blackmore, S.; Li, C. S.

    2014-09-01

    The Hengduan Mountains, with their strong altitudinal vegetation zonation, form a biodiversity hotspot which offers the potential for comparison between sites in order to understand how this zonation arose and how it has responded to climate change and human impacts through time. This paper is one of the studies covering a range of altitudes within this hotspot, and presents a 22 570 yr pollen record of vegetational and climatic change based on a core 320 cm in depth collected from Wenhai Lake on the Jade Dragon Snow Mountain, one of the highest peaks in the Hengduan Mountains region of Yunnan, Southwest China. From 22 570 to 21 140 cal. yr BP, the vegetation was dominated by broad-leaved forest (comprising mainly Quercus, Betula and Castanopsis), accompanied by coniferous Pinus and Abies and the drought-tolerant herb Artemisia, indicating a cool and dry climate. In the period between 21 140 and 19 350 cal. yr BP, the vegetation was still dominated by broad-leaved forest but with a notable increase in pollen of aquatic plants, implying a relatively warm and moderately humid climate. The period 19 350 to 17 930 cal. yr BP was a transition stage from broad-leaved forest to needle-leaved forest, reflecting a warm-humid climate at the beginning and a cold-dry one at the end. Between 17 930 and 9250 cal. yr BP, needle-leaved forest and broad-leaved forest alternated in dominance in the early stages, with the former taking the predominant position by the end of the period, suggesting a climate fluctuating between warm-humid and cold-dry. From 9250 cal. yr BP to present, the vegetation has been dominated by needle-leaved forest (comprising mainly Pinus and Abies), coupled with broad-leaved forest (mainly Quercus and Betula), reflecting a transition in climatic conditions from warm-humid to cold-humid. During this period, human activity increased in this region, with impacts on the vegetation which may be evidenced by the distinct decrease in Pinus and Quercus pollen and

  18. 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

  19. Osmolality and non-structural carbohydrate composition in the secondary phloem of trees across a latitudinal gradient in Europe

    Directory of Open Access Journals (Sweden)

    Anna eLintunen

    2016-06-01

    Full Text Available Phloem osmolality and its components are involved in basic cell metabolism, cell growth, and in various physiological processes including the ability of living cells to withstand drought and frost. Osmolality and sugar composition responses to environmental stresses have been extensively studied for leaves, but less for the secondary phloem of plant stems and branches. Leaf osmotic concentration and the share of pinitol and raffinose among soluble sugars increase with increasing drought or cold stress, and osmotic concentration is adjusted with osmoregulation. We hypothesize that similar responses occur in the secondary phloem of branches. We collected living bark samples from branches of adult Pinus sylvestris, Picea abies, Betula pendula and Populus tremula trees across Europe, from boreal Northern Finland to Mediterranean Portugal. In all studied species, the observed variation in phloem osmolality was mainly driven by variation in phloem water content, while tissue solute content was rather constant across regions. Osmoregulation, in which osmolality is controlled by variable tissue solute content, was stronger for Betula and Populus in comparison to the evergreen conifers. Osmolality was lowest in mid-latitude region, and from there increased by 37% towards northern Europe and 38% towards southern Europe due to low phloem water content in these regions. The ratio of raffinose to all soluble sugars was negligible at mid-latitudes and increased towards north and south, reflecting its role in cold and drought tolerance. For pinitol, another sugar known for contributing to stress tolerance, no such latitudinal pattern was observed. The proportion of sucrose was remarkably low and that of hexoses (i.e. glucose and fructose high at mid-latitudes. The ratio of starch to all non-structural carbohydrates increased towards the northern latitudes in agreement with the build-up of osmotically inactive C reservoir that can be converted into soluble

  20. 基于CCA排序的霍山森林植物功能型划分%Classification of Plant Functional Types Based on CCA Ordination in Forest at Huoshan Mountain

    Institute of Scientific and Technical Information of China (English)

    丁献华; 毕润成; 闫明

    2011-01-01

    采用群落生态学的调查方法,在霍山七里峪设置80个样方并采集土壤样品.通过计算重要值和测定土壤理化性质(pH值、含水量、有机质含量、N、P、K含量),建立样方×物种矩阵和样方×环境矩阵,用CCA排序划分植物功能型.结果表明,随着海拔等环境因子的变化,可以将七里峪天然次生林划分为:F1山核桃Carya cathayensis Sarg.、虎榛子Ostryopsis davidiana Decaisne、披针叶苔草Carex lanceolata Boott.;F2油松Pinus tabulaeformis Carr.、三裂绣线菊Spiraea trilobata Linn.、荩草Arthraxon hispidus(Thunb.)Makio.;F3辽东栎Quercus wutaishanica Blume、连翘Forsythia suspensa(Thunb.)Vahl.Enum.、披针叶苔草;F4华北落叶松Larix principis-rupprechtii Mayr.、美丽胡枝子Lespedeza formosa(Vog.)Koehne、林荫千里光Senecio nemorensis Linn;F5 白桦Betula platyphylla Suk、毛榛子Corylus heterophylla Fisch.Ex Trautv.、披针叶苔草5个功能型.%This thesis adopted the investigation method of community ecology, 80 quadrates were set up and 80 soil samples were collected from QiLiYu. of Huoshan Mountain. By calculating the importance value and measurement the soil physical and chemical properfies ( soil pH, contents of soil water, contents of organic, N, P, K, etc. ), matrix of quadrates × species and matrix of quadrates × environmental factors were established. PlFls were defined according to CCA ordination. The results showed that: With changes of elevation and other environmental factors, HuoMountainQiliyu secondary forest can be divided into:Fl Carya cathayensis Sarg., Ostryopsis davidiana Decaisne, Carex lanceolata Boott. ; F2 Pinus tabulaeformis Carr. , Quercus wutaishanica Blume, Spiraea trilobata Linn, Arthraxon hispidus ( Thunb. ) Makio.; F3 Quercus wutaishanica Blume, Forsythia suspensa ( Thunb. ) Vahl. Eunm,, Carex lunceolata Boott. ;F4 Larix principis-rupprechtii Mayr. , Lespedeza formosa ( Vng. ) Koehne、Senecio nemorensis Linn;F5 Betula platyphylla

  1. Transformation of Carbon and Nitrogen by Earthworms in the Decomposition Processes of Broad-leaved Litters

    Institute of Scientific and Technical Information of China (English)

    DONG Weihua; YIN Xiuqin

    2007-01-01

    Earthworms are the important constituents in the decayed food web and the main ecological conditioners in the process of decomposition and nutrient mineralization. The transformation of organic carbon (C) and total nitrogen (N) in the broad-leaved litters ingested by earthworms was researched by means of a laboratory experiment. Experimental samples were collected from broad-leaved Korea Pine mixed forest in Liangshui National Natural Reserve (47°10'50"N, 128°53'20"E) in the northeastern Xiao Hinggan Mountains of Northeast China. The contents of organic C and total N in earthworms, leaf litters and earthworm faeces were analyzed. Results show that the organic C content was in the following order: leaf litters>faeces>earthworms, while total N content was contrary to that of the organic C. The organic C contents in the different leaf litters were in the following order: Tilia amurensis>Betula costata>Acer mono, whereas the total N contents in the different leaf litters were: Betula costata>Tilia amurensis>Acer mono. The contents of organic C and total N in the faeces from the different leaf litters were almost consistent with the contents of the leaf litters. After the leaf litters were ingested by earthworms, the organic C, which was transformed to increase earthworms' weights, accounted for 3.90%-13.31% of the total ingestion by earthworms, while that in the earthworm faeces accounted for 6.14%-13.70%. The transformed organic C through the other metabolism (e.g., respiration) of earthworms accounted for 75.04%-89.92%. The ingested organic C by earthworms was mostly used for metabolic activities. The N ingested by earthworms was less than organic C. It is estimated that 37.08% of total N was transformed to increase the earthworm's weight, 19.97% into earthworm faeces and 47.86% for the consumption of the earthworm's activities. The earthworms not only increased the content of organic C and total N in the soil, but also decreased the values of C/N in

  2. Responses of gas exchange and plant hydraulic conductance to water deficit in silver birch trees growing under increasing atmospheric humidity

    Science.gov (United States)

    Sellin, Arne; Kupper, Priit

    2013-04-01

    Climate change scenarios predict increase in air temperature by 3.5-5° C and precipitation by 5-30% in boreal and northern temperate regions of Europe by the end of the century. On the other hand, climate extremes including heat waves and droughts are projected to become more frequent and last longer across Europe over the 21st century. Increasing atmospheric humidity inevitably occurring with more frequent rainfall events reduce water fluxes through the vegetation, and have an effect on the structure of leaves and vascular tissues, plant hydraulic properties, biomass allocation, nutrient uptake and growth (Tullus et al. 2012). We investigated fast and long-term effects of water deficit on plant water status, gas exchange and hydraulic conductance on saplings of silver birch (Betula pendula) growing under artificially manipulated air humidity in an experimental forest ecosystem at the Free Air Humidity Manipulation site (http://www.lote.ut.ee/FAHM/in-english; Kupper et al. 2011). Fast-developing water deficit was imposed by letting cut sample branches to dehydrate in open-air conditions, long-term water deficit was generated by seasonal drought. The fast-imposed water deficit estimated by leaf (ΨL) or branch water status (ΨB) had highly significant (P

  3. Humus bacteria of Norway spruce stands: plant growth promoting properties and birch, red fescue and alder colonizing capacity.

    Science.gov (United States)

    Elo; Maunuksela; Salkinoja-Salonen; Smolander; Haahtela

    2000-02-01

    We studied the potential of the humus layer of the Norway spruce stands to supply beneficial rhizobacteria to birch (Betula pendula), alder (Alnus incana) and fescue grass (Festuca rubra), representatives of pioneer vegetation after clear-cutting of the coniferous forest. Axenically grown seedlings of these species were inoculated with the acid spruce humus, pH 3.7-5.3. Actinorhizal propagules, capable of nodulating alder, were present in high density (10(3) g(-1)) in humus of long-term limed plots, whereas plots with nitrogen fertilization contained almost none (

  4. A plant toxin mediated mechanism for the lag in snowshoe hare population recovery following cyclic declines

    Science.gov (United States)

    DeAngelis, Donald L.; Bryant, John P.; Liu, Rongsong; Gourley, Stephen A.; Krebs, Charles J; Reichardt, Paul B

    2015-01-01

    A necessary condition for a snowshoe hare population to cycle is reduced reproduction after the population declines. But the cause of a cyclic snowshoe hare population's reduced reproduction during the low phase of the cycle, when predator density collapses, is not completely understood. We propose that moderate-severe browsing by snowshoe hares upon preferred winter-foods could increase the toxicity of some of the hare's best winter-foods during the following hare low, with the result being a decline in hare nutrition that could reduce hare reproduction. We used a combination of modeling and experiments to explore this hypothesis. Using the shrub birch Betula glandulosa as the plant of interest, the model predicted that browsing by hares during a hare cycle peak, by increasing the toxicity B. glandulosa twigs during the following hare low, could cause a hare population to cycle. The model's assumptions were verified with assays of dammarane triterpenes in segments of B. glandulosa twigs and captive hare feeding experiments conducted in Alaska during February and March 1986. The model's predictions were tested with estimates of hare density and measurements of B. glandulosa twig growth made at Kluane, Yukon from 1988–2008. The empirical tests supported the model's predictions. Thus, we have concluded that a browsing-caused increase in twig toxicity that occurs during the hare cycle's low phase could reduce hare reproduction during the low phase of the hare cycle.

  5. Growth responses of gypsy moth larvae to elevated CO2:the influence of methods of insect rearing

    Institute of Scientific and Technical Information of China (English)

    Lan-Zhu Ji; Lin-Li An; Xiao-Wei Wang

    2011-01-01

    The effects of elevated CO2 on foliar chemistry of two tree species (Populus pseudo-simonii Kitag.and Betula platyphylla) and on growth of gypsy moth (Lymantria dispar L.) larvae were examined.Furthermore,we focused on the comparison of results on the growth responses of larvae obtained from two methods of insect rearing,the nochoice feeding trial performed in the laboratory or in situ in open-top chambers.On the whole,both primary and secondary metabolites in the leaves of the two tree species were significantly affected by main effects of time (sampling date),CO2 and species.Elevated CO2 significantly increased the C:N ratio and concentrations of the soluble sugar,starch,total nonstructural carbohydrates,total phenolics and condensed tannins,but significantly decreased the concentration of nitrogen.Higher contents of total phenolics and condensed tannins were detected in the frass of larvae reared in elevated CO2 treatments.Overall,the growth of gypsy moth larvae were significantly inhibited by elevated CO2 and CO2induced changes in leaf quality.Our study did not indicate the two methods of insect rearing could influence the direction of effects of elevated CO2 on the growth of individual insects; however,the magnitude of negative effects of elevated CO2 on larval growth did differ between the two insect rearing methods,and it seems that the response magnitude was also mediated by larval age and host plant species.

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

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    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.

  7. Glacial Refugium of Pinus pumila (Pall.) Regel in Northeastern Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Shilo, N A; Lozhkin, A V; Anderson, P M; Brown, T A; Pakhomov, A Y; Solomatkina, T B

    2007-02-10

    One of the most glowing representatives of the Kolyma flora [1], ''Pinus pumila'' (Pall.) Regel (Japanese stone pine), is a typical shrub in larch forests of the northern Okhotsk region, basins of the Kolyma and Indigirka rivers, and high-shrub tundra of the Chukchi Peninsula. It also forms a pine belt in mountains above the forest boundary, which gives way to the grass-underbrush mountain tundra and bald mountains. In the southern Chukchi Peninsula, ''Pinus pumila'' along with ''Duschekia fruticosa'' (Rupr.) Pouzar and ''Betula middendorffii'' Trautv. et C. A. Mey form trailing forests transitional between tundra and taiga [2]. Pinus pumila pollen, usually predominating in subfossil spore-and-pollen spectra of northeastern Siberia, is found as single grains or a subordinate component (up 2-3%, rarely 10%) in spectra of lacustrine deposits formed during the last glacial stage (isotope stage 2) in the Preboreal and Boreal times of the Holocene. Sometimes, its content increases to 15-22% in spectra of lacustrine deposits synchronous to the last glacial stage near the northern coast of the Sea of Okhotsk [3], evidently indicating the proximity of Japanese stone pine thickets.

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

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    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.

  9. Analysis of organic acids in selected forest litters of Northeast China

    Institute of Scientific and Technical Information of China (English)

    SONGJin-feng; CUIXiao-yang

    2003-01-01

    Larch (Larix olgensis), Manchurian ash (Fraxinus mandshurica), Korean pine (Pinus koraiensis) and White birch (Betula platyphylla) are the major planting species in northeast China. The samples of forest litters were collected from the stands of the above 4 species in Laoyeling and Jianlagou experiment stations of Maorshan Exp. Forest Farm (45°12′-45°30′N,127°30′-127°48′E), Northeast Forestry University, in early October 2002. Quantitative analysis and qualitative analysis were carried out on the organic acids existing in freshly fallen litters (L layer) and hemi-decomposed litters (F layer) of the four forest species by using Gas Chromatogram system. A wide variety of organic acids were identified, including oxalic, malonic, fumaric,succinic, maleic, malic, citric, C16:0, C18:0, C18:1, C18:2, C18:3 and C20:0 acids. In respect of L litters of all samples, the oxalic acid content (over 30 mg/g) was the highest of the seven low-molecular-weight organic acids identified, while the content of oleic or linoleic (above 40 mg/g) was found to be highest among the six high aliphatic acids identified. As to F litters, oxalic acid content was also the highest, followed by linoleic and oleic. For the same tree species or the same forest, the kinds and contents of organic acids in L litters were more abundant than that in F litters.

  10. Carbon constrains fungal endophyte assemblages along the timberline.

    Science.gov (United States)

    Yang, Teng; Weisenhorn, Pamela; Gilbert, Jack A; Ni, Yingying; Sun, Ruibo; Shi, Yu; Chu, Haiyan

    2016-09-01

    The alpha diversity of foliar fungal endophytes (FEs) in leaves of Betula ermanii in a subalpine timberline ecotone on Changbai Mountain, China increased with elevation. There were also significant differences in beta diversity along the elevation gradient. Among the environmental variables analysed, leaf carbon significantly increased with elevation, and was the most significant environmental factor that constrained the alpha and beta diversity in the FE communities. Tree height and the cellulose, lignin, and carbon/nitrogen ratio of the leaves also affected the FE assemblages. When controlled for the effects of elevation, leaf carbon was still the main driver of changes in evenness, Shannon diversity and FE community composition. The results offered clues of the carbon acquisition strategy of the foliar FEs across this cold terrain. There was strong multicollinearity between both annual precipitation and temperature, with elevation (|Pearson r| > 0.986), so the effects of these climatic variables were impossible to separate; however, they may play key roles, and the direct effects of both warrant further investigation. As pioneer decomposers of leaf litter, variations in diversity and community composition of FE measured here may feedback and influence carbon cycling and dynamics in these forest ecosystems.

  11. Unified phenology model with Bayesian calibration for several European species in Belgium

    Science.gov (United States)

    Fu, Y. S. H.; Demarée, G.; Hamdi, R.; Deckmyn, A.; Deckmyn, G.; Janssens, I. A.

    2009-04-01

    Plant phenology is a good bio-indicator for climate change, and this has brought a significant increase of interest. Many kinds of phenology models have been developed to analyze and predict the phenological response to climate change, and those models have been summarized into one kind of unified model, which could be applied to different species and environments. In our study, we selected seven European woody plant species (Betula verrucosa, Quercus robur pedunculata, Fagus sylvatica, Fraxinus excelsior, Symphoricarpus racemosus, Aesculus hippocastanum, Robinia pseudoacacia) occurring in five sites distributed across Belgium. For those sites and tree species, phenological observations such as bud burst were available for the period 1956 - 2002. We also obtained regional downscaled climatic data for each of these sites, and combined both data sets to test the unified model. We used a Bayesian approach to generate distributions of model parameters from the observation data. In this poster presentation, we compare parameter distributions between different species and between different sites for individual species. The results of the unified model show a good agreement with the observations, except for Fagus sylvatica. The failure to reproduce the bud burst data for Fagus sylvatica suggest that the other factors not included in the unified model affect the phenology of this species. The parameter series show differences among species as we expected. However, they also differed strongly for the same species among sites.Further work should elucidate the mechanism that explains why model parameters differ among species and sites.

  12. Assessment of the urban trees health status on the base of nutrient and pigment content in their leaves

    Directory of Open Access Journals (Sweden)

    SLAVEYA PETROVA

    2014-04-01

    Full Text Available Town settlements have different load level by emissions originated mostly from transport, industry and heating system. Their environmental and climate conditions are more or less changed that effect to growth, physiology and vigor of woody plants at the city public vegetation areas. Our study on determining the impact of urban environment on the tree health status was focused on the quantities of nutrients and main components of the pigment complex – chlorophyll a, chlorophyll b and carotenoids. Leaves of Acer platanoides L., Aesculus hippocastanum L. and Betula pendula Roth. were sampled from urban areas with different type of anthropogenic pressure in the town of Plovdiv (Bulgaria. Concentrations of the elements Ca, K, Mg, N, Na, P, and S were analyzed by ICP-MS. Health condition of trees in the city parks and suburban areas was acceptable, but in the central part and close to the industrial area it was non-satisfactory. This preliminary research pointed ecophysiological tools as useful to develop new criteria for sustainable urban arboriculture, including species selection (based on stress tolerance criteria, nursery hardening and preconditioning, and care after planting.

  13. Antibacterial and quorum sensing regulatory activities of some traditional Eastern-European medicinal plants

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    Tolmacheva Anna A.

    2014-06-01

    Full Text Available The objective of this study was to screen extracts of twenty Eastern European medicinal plants, using wild-type and reporter Chromobacterium violaceum bioassays, for novel components that target bacterial cells and their quorum sensing (QS communication systems. Three types of activity and their combinations were revealed: (i direct antimicrobial growth-inhibitory activity, (ii non-specific and specific pro-QS activities, (iii anti-QS activity. Among seven plant extracts showing direct growth-inhibitory activity, the strongest effect was shown by Arctostaphylos uva- -ursi (bearberry leaves. Many plants stimulated violacein production by wild-type C. violaceum ATCC 31532 in a non-specific manner, and only the herb Bidens tripartita (three-lobe beggarticks contained compounds that mimic acyl-homoserine lactone and operated as a QS agonist. Anti-QS activity was found in eleven plants including Quercus robur (oak cortex, Betula verrucosa (birch buds and Eucalyptus viminalis (Manna Gum leaves. Subsequent statistical analysis showed differences between antimicrobial and anti-QS activities, whereas both activities were defined by phylogenetic position of medical resource plant. Finally, extract from Quercus robur cortex revealed at least two fractions, showing different anti-QS mechanisms. These data confirm that multicomponent anti-infectious mechanisms are used by plants, which may be useful for drug development

  14. Moss mites (Acari: Oribatida in soil revitalizing: a chance for practical application in silviculture

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    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.

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

    Science.gov (United States)

    Zeng, Fansuo; Sun, Fengkun; Li, Leilei; Liu, Kun; Zhan, Yaguang

    2014-01-01

    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.

  16. Effects of litter quality and climate change along an elevational gradient on litter decomposition of subalpine forests, Eastern Tibetan Plateau, China

    Institute of Scientific and Technical Information of China (English)

    Zhenfeng Xu; Jianxiao Zhu; Fuzhong Wu; Yang Liu; Bo Tan; Wanqin Yang

    2016-01-01

    Temperature and freeze-thaw events are two key factors controlling litter decomposition in cold biomes. Predicted global warming and changes in freeze-thaw cycles therefore may directly or indirectly impact litter decomposition in those ecosystems. Here, we conducted a 2-year-long litter decomposition experiment along an ele-vational gradient from 3000 to 3600 m to determine the potential effects of litter quality, climate warming and freeze-thaw on the mass losses of three litter types [dragon spruce (Picea asperata Mast.), red birch (Betula albosi-nensis Burk.), and minjiang fir (Abies faxoniana Rehd. et Wild)]. Marked differences in mass loss were observed among the litter types and sampling dates. Decay constant (k) values of red birch were significantly higher than those of the needle litters. However, mass losses between ele-vations did not differ significantly for any litter type. During the winter, lost mass contributed 18.3–28.8% of the net loss rates of the first year. Statistical analysis showed that the relationships between mass loss and litter chemistry or their ratios varied with decomposition peri-ods. Our results indicated that short-term field incubations could overestimate the k value of litter decomposition. Considerable mass was lost from subalpine forest litters during the wintertime. Potential future warming may not affect the litter decomposition in the subalpine forest ecosystems of eastern Tibetan Plateau.

  17. Genetic and environmental factors behind foliar chemistry of the mature mountain birch.

    Science.gov (United States)

    Haviola, Sanna; Neuvonen, Seppo; Rantala, Markus J; Saikkonen, Kari; Salminen, Juha-Pekka; Saloniemi, Irma; Yang, Shiyong; Ruuhola, Teija

    2012-07-01

    Previous studies of mountain birch (Betula pubescens spp. czerepanovii) repeatedly have found differences between individual trees in herbivory-related traits, but rarely have yielded estimates of the additive genetic variation of these traits or of their relationship to habitat. We used thirty-year-old birch half-sibs in a northern common garden to estimate the effect of genetics and local microhabitat on resistance-related traits. Genetic estimates of foliar chemistry have been studied only rarely with trees as old as these. Moth performance (Epirrita autumnata), rust (Melampsoridium betulinum) incidence levels, and the general level of natural herbivory damage to individual trees were used as direct measures of birch resistance. Chemical resistance-related traits in plant chemistry included 15 individual phenolics, 16 amino acids, and phenoloxidase activities in the foliage. We also followed birch phenology and growth. Our results show that the genotype of the birch was the most important determinant of phenolic composition and phenoloxidase activity, but that amino acid levels were best explained by the microhabitat of the birch. We also found that the phenology of the birch had a high heritability, although its variation was low. Our results reveal rich genetic variation in birch chemistry.

  18. INHIBITION OF THE LIPID OXIDATION PROCESSES BY THE KAZAKHSTANI-SOIL ENDEMIC PLANTS

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    Mashentseva A.A

    2009-12-01

    Full Text Available Phospholipids (PL are universal components of cell membranes. They can be used as objective indices of normal or pathological organism states. The changing nature of the quantitative composition of PL is indicating the intensity of oxidative stress as well as the efficiency of exogenous plant antioxidants.The PL dynamics of the ischemia in experimental rat’s was investigated. The change of that parameter using the preventive injection of some vegetation organs of Kazakhstan birch extract.The extracts of the birch vegetation organs in experimental group were dosed in the amount of 5 mg/kg. In order to investigate PL dynamics, the tissues of brain, liver, and kidney have been studied.In order to estimate the PL change range in rat homogenate, the correlation between neutral and acid PL. Despite the fact that the amount of acid PL in the bio-membranes is less than the neutral ones, the latter regulate membrane functions in a higher degree.It has been found that the rats which had experienced ischemia have a decreased amount of acid PL in the homogenates. Preventive injection of birch extracts brings about normalization of PL level. This fact points out a possibility of applying extracts of Betula Pendula Roth in order to regulate the PL level of experimental rats as well as an estimation of the antioxidant effect of exogenoussubstances.

  19. Spatial heterogeneity in the timing of birch budburst in response to future climate warming in Ireland

    Science.gov (United States)

    Caffarra, Amelia; Zottele, Fabio; Gleeson, Emily; Donnelly, Alison

    2014-05-01

    In order to predict the impact of future climate warming on trees it is important to quantify the effect climate has on their development. Our understanding of the phenological response to environmental drivers has given rise to various mathematical models of the annual growth cycle of plants. These models simulate the timing of phenophases by quantifying the relationship between development and its triggers, typically temperature. In addition, other environmental variables have an important role in determining the timing of budburst. For example, photoperiod has been shown to have a strong influence on phenological events of a number of tree species, including Betula pubescens (birch). A recently developed model for birch (DORMPHOT), which integrates the effects of temperature and photoperiod on budburst, was applied to future temperature projections from a 19-member ensemble of regional climate simulations (on a 25 km grid) generated as part of the ENSEMBLES project, to simulate the timing of birch budburst in Ireland each year up to the end of the present century. Gridded temperature time series data from the climate simulations were used as input to the DORMPHOT model to simulate future budburst timing. The results showed an advancing trend in the timing of birch budburst over most regions in Ireland up to 2100. Interestingly, this trend appeared greater in the northeast of the country than in the southwest, where budburst is currently relatively early. These results could have implications for future forest planning, species distribution modeling, and the birch allergy season.

  20. Lack of Correlation between Ammonium Accumulation and Survival of Transgenic Birch Plants with Pine Cytosolic Glutamine Synthetase Gene after “Basta” Herbicide Treatment

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    Vadim Lebedev

    2015-01-01

    Full Text Available Transformation of plants with genes encoding a glutamine synthetase (GS, a key nitrogen metabolism enzyme, is usually used to increase productivity. However, overexpression of these genes may increase resistance to phosphinothricin (PPT that irreversibly inhibits GS causing ammonium accumulation in plant tissues. Transgenic plants of two birch (Betula pubescens genotypes expressing a pine cytosolic GS gene were used for studying the PPT effect on trees. Two control and 8 transgenic lines were treated with herbicide “Basta” at dose equivalent to 2.5 and 5 Lha−1. Necrosis and abscission of leaves occurred irrespective of a transgenic status or the treatment dose. Ammonium content in leaf tissue in 3 days after the 5 Lha−1 treatment was substantially increased in all plants, 3.2–16.0 times depending on line. After the 2.5 Lha−1 treatment, ammonium content in three transgenic lines was not different from that in control variant sprayed with water. The herbicide treatment caused more prominent desiccation in the bp3f1 genotype nontransgenic plants as compared to transgenic plants, but not in the bp4a genotype. Lack of correlation between ammonium levels and survival of transgenic plants suggests that ammonium toxicity is not a main reason for the birch plant death after the PPT treatment.

  1. Asynchrony between Host Plant and Insects-Defoliator within a Tritrophic System: The Role of Herbivore Innate Immunity.

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    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.

  2. Carbohydrate concentrations and freezing stress resistance of silver birch buds grown under elevated temperature and ozone.

    Science.gov (United States)

    Riikonen, Johanna; Kontunen-Soppela, Sari; Vapaavuori, Elina; Tervahauta, Arja; Tuomainen, Marjo; Oksanen, Elina

    2013-03-01

    The effects of slightly elevated temperature (+0.8 °C), ozone (O3) concentration (1.3 × ambient O3 concentration) and their combination on over-wintering buds of Betula pendula Roth were studied after two growing seasons of exposure in the field. Carbohydrate concentrations, freezing stress resistance (FSR), bud dry weight to fresh weight ratio, and transcript levels of cytochrome oxidase (COX), alternative oxidase (AOX) and dehydrin (LTI36) genes were studied in two clones (clones 12 and 25) in December. Elevated temperature increased the bud dry weight to fresh weight ratio and the ratio of raffinose family oligosaccharides to sucrose and the transcript levels of the dehydrin (LTI36) gene (in clone 12 only), but did not alter the FSR of the buds. Genotype-specific alterations in carbohydrate metabolism were found in the buds grown under elevated O3. The treatments did not significantly affect the transcript level of the COX or AOX genes. No clear pattern of an interactive effect between elevated temperature and O3 concentration was found. According to these data, the increase in autumnal temperatures and slightly increasing O3 concentrations do not increase the risk for freeze-induced damage in winter in silver birch buds, although some alterations in bud physiology occur.

  3. Biochemical and growth acclimation of birch to night temperatures: genotypic similarities and differences.

    Science.gov (United States)

    Mäenpää, M; Ossipov, V; Kontunen-Soppela, S; Keinänen, M; Rousi, M; Oksanen, E

    2013-01-01

    The responses of plants to environmental factors are connected to the time of day. In this study, silver birch (Betula pendula) was grown in growth chambers at five different night temperatures (6-22 °C), using gradual changes during the evening and morning hours. Despite the increased night respiration and unaffected daytime net photosynthesis (per square metre), the carbon uptake (biomass) of birch did not decrease, probably due to enhanced biochemical processes on warmer nights and the advantage of higher temperatures during the evening and morning hours. The plant stem height, internode length, stem dry weight (DW), stem mass fraction and specific leaf area increased with warmer night temperatures. Changes in growth and metabolite concentrations were partly nonlinear along the temperature gradient. Thus, the temperature effect depends on the temperature window considered. Genotypes had both common and genotype-specific biochemical responses to night temperatures. The common responses among genotypes were related to growth responses, whereas the unique responses may indicate genotype-specific differences in acclimation. The differences in genotypic growth and metabolite levels are valuable for assessing genotype qualities and understanding the connections between the metabolome and growth.

  4. Can antibrowsing defense regulate the spread of woody vegetation in arctic tundra?

    Science.gov (United States)

    Bryant, John P.; Joly, Kyle; Chapin, F. Stuart; DeAngelis, Donald L.; Kielland, Knut

    2014-01-01

    Global climate warming is projected to promote the increase of woody plants, especially shrubs, in arctic tundra. Many factors may affect the extent of this increase, including browsing by mammals. We hypothesize that across the Arctic the effect of browsing will vary because of regional variation in antibrowsing chemical defense. Using birch (Betula) as a case study, we propose that browsing is unlikely to retard birch expansion in the region extending eastward from the Lena River in central Siberia across Beringia and the continental tundra of central and eastern Canada where the more effectively defended resin birches predominate. Browsing is more likely to retard birch expansion in tundra west of the Lena to Fennoscandia, Iceland, Greenland and South Baffin Island where the less effectively defended non-resin birches predominate. Evidence from the literature supports this hypothesis. We further suggest that the effect of warming on the supply of plant-available nitrogen will not significantly change either this pan-Arctic pattern of variation in antibrowsing defense or the resultant effect that browsing has on birch expansion in tundra. However, within central and east Beringia warming-caused increases in plant-available nitrogen combined with wildfire could initiate amplifying feedback loops that could accelerate shrubification of tundra by the more effectively defended resin birches. This accelerated shrubification of tundra by resin birch, if extensive, could reduce the food supply of caribou causing population declines. We conclude with a brief discussion of modeling methods that show promise in projecting invasion of tundra by woody plants.

  5. The effects of soil and air temperature on CO2 exchange and net biomass accumulation in Norway spruce, Scots pine and silver birch seedlings.

    Science.gov (United States)

    Pumpanen, Jukka; Heinonsalo, Jussi; Rasilo, Terhi; Villemot, Julie; Ilvesniemi, Hannu

    2012-06-01

    Soil temperature is proposed to affect the photosynthetic rate and carbon allocation in boreal trees through sink limitation. The aim of this study was to investigate the effect of temperature on CO(2) exchange, biomass partitioning and ectomycorrhizal (ECM) fungi of boreal tree species. We measured carbon allocation, above- and below-ground CO(2) exchange and the species composition of associated ECM fungi in the rhizosphere of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies K.) and silver birch (Betula pendula Roth) seedlings grown in soil maintained at 7-12, 12-15 and 16-22 °C. We found increased root biomass and photosynthetic rate at higher soil temperatures, but simultaneously with photosynthesis rate, higher temperature generally increased soil respiration as well as shoot, and root and rhizosphere respiration. The net CO(2) exchange and seedling biomass did not increase significantly with increasing temperature due to a concomitant increase in carbon assimilation and respiration rates. The 2-month-long growth period in different soil temperatures did not alter the ECM fungi species composition and the below-ground carbon sink strength did not seem to be directly related to ECM biomass and species composition in any of the tree species. Ectomycorrhizal species composition and number of mycorrhiza did not explain the CO(2) exchange results at different temperatures.

  6. Elevated CO2 changes the moderate shade tolerance of yellow birch seedlings

    Institute of Scientific and Technical Information of China (English)

    CHENG Song

    2007-01-01

    To demonstrate the existence of light thresholds in plant growth and to examine the effects of elevated CO2 on the shade tolerance of a tree species, an experiment consisting of a completely randomized design for a total of 96 yellow birch (Betula alleghaniensis Britton) seedlings was conducted with 3 light levels (2.9%, 7.7%, 26.1% of full sunlight) × 2 CO2 levels (350 and 700±10 ppm) with 4 replications in a phytotron. The study proved that thresholds exist and they vary in different plant organs. In ambient CO2, the thresholds were 13.3%, 18.7%, 15.0%, 15.2%, and 15.6% of full sunlight for stem, leaf, root, total plant biomass, and the averaged value, respectively. In 700 ppm CO2, the corresponding thresholds were 16.7%, 21.3%, 18.1%, 21.7% and 19.5% for stem, leaf, root, total plant biomass, and the averaged value, respectively. The lowest threshold in the stem is an indicator of the minimal light intensity for regular growth for seedlings of this species. Below this threshold, light-stressful growth occurs. The result of a paired t-test indicated that the thresholds in elevated CO2 were significantly higher than in ambient CO2. This suggests that yellow birch will lose its moderate shade tolerance, evolutionally becoming a shade-intolerant species, and that it may become more difficult for it to naturally regenerate in the future.

  7. Effect of betulin-containing extract from birch tree bark on α-amylase activity in vitro and on weight gain of broiler chickens in vivo.

    Science.gov (United States)

    Ilyina, Anna; Arredondo-Valdés, Roberto; Farkhutdinov, Salavat; Segura-Ceniceros, Elda Patricia; Martínez-Hernández, José Luis; Zaynullin, Radik; Kunakova, Rayhana

    2014-03-01

    In vitro effect of betulin-containing extract from Betula pendula Roth. bark on alpha-amylase activity was studied, the kinetic mechanism of interaction was proposed and in vivo effect of betulin-containing extract on weight gain and meat quality of broiler chickens was evaluated. The highest level of inhibitory activity (20%) was detected in extract concentration of 1,000 mg/L. Increased extract concentration did not lead to increased enzyme inhibition. Using Dixon and Cornish-Bowden coordinates, the competitive mechanism of inhibition was demonstrated. Calculated kinetic parameters were: Km equal to 0.6 mg/mL, Vmax equal to 2.6 and 2.1 mM/min from Lineweaver-Burk and Dixon coordinates, respectively and Ki equal to 3,670 ± 230 mg/mL. The partial inhibition of enzyme indicates the existence of low concentration of active inhibitory form, which reaches saturation level with increased extract concentration in applied suspension. Therefore, Ki has an apparent constant character. This partial inhibition of amylase activity observed in in vitro assay did not affect weight gain and meat quality of broiler chickens during in vivo assay. Rather, the tendency to increase the weight of edible parts and muscles compared to diet without additive suggests that the extract may be a potential food additive in poultry farming. Additionally, it could be a source for further pharmaceutical and pharmacological research.

  8. 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.

  9. Nitration of the pollen allergen bet v 1.0101 enhances the presentation of bet v 1-derived peptides by HLA-DR on human dendritic cells.

    Directory of Open Access Journals (Sweden)

    Anette C Karle

    Full Text Available Nitration of pollen derived allergens can occur by NO(2 and ozone in polluted air and it has already been shown that nitrated major birch (Betula verrucosa pollen allergen Bet v 1.0101 (Bet v 1 exhibits an increased potency to trigger an immune response. However, the mechanisms by which nitration might contribute to the induction of allergy are still unknown. In this study, we assessed the effect of chemically induced nitration of Bet v 1 on the generation of HLA-DR associated peptides. Human dendritic cells were loaded with unmodified Bet v 1 or nitrated Bet v 1, and the naturally processed HLA-DR associated peptides were subsequently identified by liquid chromatography-mass spectrometry. Nitration of Bet v 1 resulted in enhanced presentation of allergen-derived HLA-DR-associated peptides. Both the copy number of Bet v 1 derived peptides as well as the number of nested clusters was increased. Our study shows that nitration of Bet v 1 alters antigen processing and presentation via HLA-DR, by enhancing both the quality and the quantity of the Bet v 1-specific peptide repertoire. These findings indicate that air pollution can contribute to allergic diseases and might also shed light on the analogous events concerning the nitration of self-proteins.

  10. [Soil nutrient status of pure birch and larch plantations based on their seedlings bioassay].

    Science.gov (United States)

    Liu, Zhong-ling; Wang, Qing-cheng; Sun, Xin-xin

    2011-08-01

    One-year-old birch (Betula platyphylla) and larch (Larix olgensis) seedlings were respectively planted in pots with the soils taken from 35-year-old pure birch and larch plantations, and the seedlings growth, biomass increment, foliar nutrient content, and soil nutrient status were monitored, aimed to evaluate the fertility levels of the two soils and the possible interspecific interaction in mixed larch-birch forest. Birch soil had significantly higher contents of total N and available N than larch soil, while larch soil had significantly higher contents of total P, available P, and total K than birch soil (P birch seedlings growing on birch soil were 69%, 52%, and 65% (P birch seedlings growing on birch soil was higher than that on larch soil, while the foliar P concentration was higher when the seedlings were growing on larch soil than on birch soil. The birch soil had higher content of available N because of the higher litterfall, while the larch soil had greater available P because of the higher P mobilizing effect. It was predicted that in mixed birch-larch forest, the complementary interaction of soil N and P could benefit the growth of the two tree species.

  11. Fungal Assemblages in Different Habitats in an Erman’s Birch Forest

    Science.gov (United States)

    Yang, Teng; Sun, Huaibo; Shen, Congcong; Chu, Haiyan

    2016-01-01

    Recent meta-analyses of fungal diversity using deeply sequenced marker genes suggest that most fungal taxa are locally distributed. However, little is known about the extent of overlap and niche partitions in total fungal communities or functional guilds within distinct habitats on a local forest scale. Here, we compared fungal communities in endosphere (leaf interior), phyllosphere (leaf interior and associated surface area) and soil samples from an Erman’s birch forest in Changbai Mountain, China. Community structures were significantly differentiated in terms of habitat, with soil having the highest fungal richness and phylogenetic diversity. Endophytic and phyllosphere fungi of Betula ermanii were more phylogenetically clustered compared with the corresponding soil fungi, indicating the ability of that host plants to filter and select their fungal partners. Furthermore, the majority of soil fungal taxa were soil specialists, while the dominant endosphere and phyllosphere taxa were aboveground generalists, with soil and plant foliage only sharing birch forest were strictly niche specialized and constrained by weak migration among habitats. The findings suggest that phylogenetic relatedness and functional guilds’ assignment can effectively interpret the certain ecological processes. PMID:27625646

  12. Betulin Derivatives Effectively Suppress Inflammation in Vitro and in Vivo.

    Science.gov (United States)

    Laavola, Mirka; Haavikko, Raisa; Hämäläinen, Mari; Leppänen, Tiina; Nieminen, Riina; Alakurtti, Sami; Moreira, Vânia M; Yli-Kauhaluoma, Jari; Moilanen, Eeva

    2016-02-26

    Betulin is a pharmacologically active triterpenoid found in the bark of the birch tree (Betula sp. L.). Betulin and betulinic acid are structurally related to anti-inflammatory steroids, but little is known about their potential anti-inflammatory properties. In the present study, the inflammatory gene expression and the anti-inflammatory properties of betulin, betulinic acid, and 16 semisynthetic betulin derivatives were investigated. Betulin derivatives 3, 4, and 5 selectively inhibited the expression of the inducible nitric oxide synthase (iNOS) in a post-transcriptional manner. They also inhibited nitric oxide (NO) production but had no effect on the other inflammatory factors studied. More interestingly, a new anti-inflammatory betulin derivative 9 with a wide-spectrum anti-inflammatory activity was discovered. Compound 9 was found to suppress the expression of cytokines interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1), as well as that of prostaglandin synthase-2 (COX-2) in addition to iNOS. The in vivo anti-inflammatory effect of compound 9 was indicated via significant suppression of the carrageenan-induced paw inflammation in mice. The results show, for the first time, that the pyrazole-fused betulin derivative (9) and related compounds have anti-inflammatory properties that could be utilized in drug development.

  13. Low vapour pressure deficit affects nitrogen nutrition and foliar metabolites in silver birch.

    Science.gov (United States)

    Lihavainen, Jenna; Ahonen, Viivi; Keski-Saari, Sarita; Kontunen-Soppela, Sari; Oksanen, Elina; Keinänen, Markku

    2016-07-01

    Air humidity indicated as vapour pressure deficit (VPD) is directly related to transpiration and stomatal function of plants. We studied the effects of VPD and nitrogen (N) supply on leaf metabolites, plant growth, and mineral nutrition with young micropropagated silver birches (Betula pendula Roth.) in a growth chamber experiment. Plants that were grown under low VPD for 26 d had higher biomass, larger stem diameter, more leaves, fewer fallen leaves, and larger total leaf area than plants that were grown under high VPD. Initially, low VPD increased height growth rate and stomatal conductance; however, the effect was transient and the differences between low and high VPD plants became smaller with time. Metabolic adjustment to low VPD reflected N deficiency. The concentrations of N, iron, chlorophyll, amino acids, and soluble carbohydrates were lower and the levels of starch, quercetin glycosides, and raffinose were higher in the leaves that had developed under low VPD compared with high VPD. Additional N supply did not fully overcome the negative effect of low VPD on nutrient status but it diminished the effects of low VPD on leaf metabolism. Thus, with high N supply, the glutamine to glutamate ratio and starch production under low VPD became comparable with the levels under high VPD. The present study demonstrates that low VPD affects carbon and nutrient homeostasis and modifies N allocation of plants.

  14. Inhibition of snowshoe hare succinate dehydrogenase activity as a mechanism of deterrence for papyriferic acid in birch.

    Science.gov (United States)

    Forbey, Jennifer Sorensen; Pu, Xinzhu; Xu, Dong; Kielland, Knut; Bryant, John

    2011-12-01

    The plant secondary metabolite papyriferic acid (PA) deters browsing by snowshoe hares (Lepus americanus) on the juvenile developmental stage of the Alaska paper birch (Betula neoalaskana). However, the physiological mechanism that reduces browsing remains unknown. We used pharmacological assays and molecular modeling to test the hypothesis that inhibition of succinate dehydrogenase (SDH) is a mode of action (MOA) of toxicity of PA in snowshoe hares. We tested this hypothesis by measuring the effect of PA on the activity of SDH in liver mitochondria isolated from wild hares. In addition, we used molecular modeling to determine the specific binding site of PA on SDH. We found that PA inhibits SDH from hares by an uncompetitive mechanism in a dose-dependent manner. Molecular modeling suggests that inhibition of SDH is a result of binding of PA at the ubiquinone binding sites in complex II. Our results provide a MOA for toxicity that may be responsible for the concentration-dependent anti-feedant effects of PA. We propose that snowshoe hares reduce the dose-dependent toxic consequences of PA by relying on efflux transporters and metabolizing enzymes that lower systemic exposure to dietary PA.

  15. Inhibition of corneal inflammation following keratoplasty by birch leaf extract.

    Science.gov (United States)

    Wacker, Katrin; Gründemann, Carsten; Kern, Yvonne; Bredow, Laura; Huber, Roman; Reinhard, Thomas; Schwartzkopff, Johannes

    2012-04-01

    The objective of this study was to determine the effect of birch leaf (Betula pendula) extract (BPE) on corneal inflammation following keratoplasty in the rat model. T cells were stimulated in vitro in the presence of BPE. Proliferation, activation phenotype and the number of apoptotic/necrotic cells in cell culture were analyzed by flow cytometry. Corneal transplantation was performed between Fisher and Lewis rats. Recipient rats were either treated with cyclosporine A at a low dosage (Low-dose CsA=LDCsA) or received LDCsA in combination with BPE (2×1ml/day). Clinical signs for corneal inflammation and rejection time points were determined. Infiltrating leukocytes were analyzed histologically. BPE specifically inhibited T cell proliferation in vitro by inducing apoptosis. The phenotype was not affected. In vivo, BPE significantly delayed the onset of corneal opacification (p<0.05). The amount of infiltrating CD45(+) leukocytes and CD4(+) T cells (p<0.001) was significantly reduced by BPE, whereas infiltration of CD163(+) macrophages was not significantly different between the two groups. BPE selectively induces apoptosis of activated T cells. Accordingly, BPE treatment significantly reduces infiltrating T cells and subsequent corneal opacification following keratoplasty. Our findings suggest BPE as a promising anti-inflammatory drug to treat corneal inflammation.

  16. Simulated browsing affects leaf shedding phenology and litter quality of oak and birch saplings.

    Science.gov (United States)

    Palacio, S; Hester, A J; Maestro, M; Millard, P

    2013-04-01

    Herbivore effects on leaf litter can have a strong impact on ecosystem nutrient cycling. Although such effects are well described for insect herbivory, research on the impacts of browsing by mammalian herbivores on leaf litter dynamics and nutrient cycling has been more limited, particularly at the level of the individual plant. Clipping treatments (66% shoot removal twice, plus unclipped) were applied to analyse the effect of browsing on the phenology (start date and pattern of leaf shedding) and leaf litter quality (nitrogen (N), soluble sugars, starch and total non-structural carbohydrate concentrations, plus C : N ratios) of Betula pubescens Ehrh. and Quercus petraea [Matt.] Liebl. saplings. Clipping decreased leaf litter biomass and delayed leaf senescence and shedding, but did not change the phenological timing of litterfall between senescence and shedding. The quality of leaf litter of both species was increased by simulated browsing, through an increase in N and carbohydrate concentrations (mainly soluble sugars) and a decreased C : N ratio. This is the first evidence we are aware of that browsing may cause changes in leaf shedding phenology, delaying the process without altering its pattern. Our results also indicate that simulated browsing increases the quality of leaf litter. However, the potential positive effect of browsing on N cycling through litter quality may be offset by its negative impact on the amount of N shed per tree.

  17. 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. PMID:26833754

  18. 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

    2015-01-01

    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. PMID:26569236

  19. Research observation: Hydrolyzable and condensed tannins in plants of the northwest

    Science.gov (United States)

    Gonzalez-Hernandez, M. P.; Karchesy, J.; Starkey, Edward E.

    2003-01-01

    Tannins are secondary metabolites that may influence feeding by mammals on plants. We analyzed hydrolyzable and condensed tannins in 30 plant species consumed by livestock and deer, as a preliminary attempt to study their possible implications on browsing and grazing in forest ecosystems. Heathers (Ericaceae) and plants of the Rose (Rosaceae) family had tannins, while forbs, grasses and shrubs other than the heathers did not show astringency properties. We found the highest tannin content of all the species in Rubus sp., with the highest value around 180 mg TAE/g dry weight in spring. Potentilla erecta, Alnus glutinosa and Quercus robur were next with 57 to 44 mg TAE/g dw. Total tannins in heathers ranged from 22 to 36 mg TAE/g dw. Levels of condensed tannins were higher than hydrolyzable for most of the species. Only Betula alba, Calluna vulgaris, Pteridium aquilinum and Vaccinium myrtillus had 100% hydrolyzable tannins. Tannin content of the species changed seasonally with highest values during the growing season, corresponding to late winter or early spring, depending on the species.

  20. Research observation: Hydrolyzable and condensed tannins in plants of northwest Spain forests

    Science.gov (United States)

    Gonzalez-Hernandez, M. P.; Karchesy, J.; Starkey, E.E.

    2003-01-01

    Tannins are secondary metabolites that may influence feeding by mammals on plants. We analyzed hydrolyzable and condensed tannins in 30 plant species consumed by livestock and deer, as a preliminary attempt to study their possible implications on browsing and grazing in forest ecosystems. Heathers (Ericaceae) and plants of the Rose (Rosaceae) family had tannins, while forbs, grasses and shrubs other than the heathers did not show astringency properties. We found the highest tannin content of all the species in Rubus sp., with the highest value around 180 mg TAE/g dry weight in spring. Potentilla erecta, Alnus glutinosa and Quercus robur were next with 57 to 44 mg TAE/g dw. Total tannins in heathers ranged from 22 to 36 mg TAE/g dw. Levels of condensed tannins were higher than hydrolyzable for most of the species. Only Betula alba, Calluna vulgaris, Pteridium aquilinum and Vaccinium myrtillus had 100% hydrolyzable tannins. Tannin content of the species changed seasonally with highest values during the growing season, corresponding to late winter or early spring, depending on the species.

  1. Environmental niche and distribution of six deciduous tree species in the Spanish Atlantic region

    Directory of Open Access Journals (Sweden)

    Roces-Díaz JV

    2015-04-01

    Full Text Available Understanding the influence of environmental factors on the distribution of tree species is essential for developing management actions at regional level. We computed species distribution models for six European tree species to determine their potential niche in the Spanish Atlantic region, where deciduous forests are relatively well preserved. We used data from the national Forest Inventory and topo-climatic and soil variables to construct distribution models by the Generalized Linear Model procedure. The main factors found to determine the presence of the selected species were minimum winter temperature and mineral fertility of soils. Suitable habitats for Quercus petraea and F. sylvatica were mainly high-altitude areas with low minimum temperatures. In contrast, Q. robur and C. sativa were restricted to low altitudes and warmer conditions. Betula pubescens was not influenced by the elevation, probably because it is adapted to Atlantic conditions, and distribution of this species was associated with low fertility soils. Although the submediterranean Q. pyrenaica was positively influenced by the slope, model performance was poor for this species, possibly because of the truncated environmental range of the species in the study area. The findings suggest that temperature rather than moisture is shaping the distribution of deciduous trees at the southern limit of the Atlantic biogeographic region. We also note that the strong elevational difference between the warm coast and the cold mountains may determine the geographical disjunction between Q. robur and Q. petraea in southern Europe.

  2. Depositional environments of the Hart coal zone (Paleocene), Willow Bunch Coalfield, southern Saskatchewan, Canada from petrographic, palynological, paleobotanical, mineral and trace element studies

    Energy Technology Data Exchange (ETDEWEB)

    Potter, J.; Beaton, A.P.; McDougall, W.J.; Nambudiri, E.M.V.; Vigrass, L.W. (University of Regina, SK (Canada). Energy Research Unit)

    1991-12-01

    Coal petrology, palynology, paleobotany and mineralogy of the Hart coal indicate deposition under wet, warm-temperate to subtropical climatic conditions in low-lying backswamps with fluvial channels and locally ponded areas. The coal is dominated by mixed xylitic/attrital lithotypes and by huminite macerals with secondary inertinite macerals and minor liptinite macerals. Good correlation exists between lithotypes and maceral composition. Local and vertical variations in proportions of huminites and inertinites reflect frequent fluctuations in water levels, periodic flooding, desiccation and burning of the peat. Swamps were dominated by {ital Glyptostrobus-Taxodium} forest with {ital Betula-Myrica-Alnus} communities and, locally {ital Laevigatosporites}, which are the dominant contributors to the xylite-rich lithotypes. Attrital lithotypes with abundant {ital Pandanus}, {ital Typha} and {ital Azolla} are consistent with wetter areas of a fluvial environment, including ponds and channels. Trace elements Cr, Cu, Mo, Ni, Si, Ti, U, Se, V, W, K and Th, typically associated with syngenetic minerals kaolinite, calcite and quartz, may have a volcanic source. High concentrations of Na, Ba and Ca found in organic complexes are of secondary origin and probably originate in deep source brines rather than marine surface waters. 55 refs., 11 figs., 5 tabs.

  3. Take me to your leader: does early successional nonhost vegetation spatially inhibit Pissodes strobi (Coleoptera: Curculionidae)?

    Science.gov (United States)

    Koopmans, Jordan M; De La Giroday, Honey-Marie C; Lindgren, B Staffan; Aukema, Brian H

    2009-08-01

    The spatial influences of host and nonhost trees and shrubs on the colonization patterns of white pine weevil Pissodes strobi (Peck) were studied within a stand of planted interior hybrid spruce [Picea glauca (Moench) Voss x Picea engelmannii (Parry) ex Engelm.]. Planted spruce accounted for one third of all trees within the stand, whereas the remaining two thirds were comprised of early-successional nonhost vegetation, such as alder (Alnus spp.), paper birch (Betula papyrifera Marsh.), black cottonwood [Populus balsamifera ssp. trichocarpa (T. Ng.) Brayshaw], lodgepole pine [Pinus contorta (Dougl.) ex Loud.], trembling aspen (Populus tremuloides Michx), willow (Salix spp.), and Canadian buffaloberry [Shepherdia canadensis (L.) Nutt.]. Unlike the spruce trees, nonhost vegetation in the stand was not uniformly distributed. Spatial point process models showed that Canadian buffaloberry, paper birch, black cottonwoood, and trembling aspen had negative associations with damage caused by the weevil, even though the density of the insects' hosts in these areas did not change. Moreover, knowing the locations of these nonhost trees provided as much, or more, inference about the locations of weevil-attacked trees as knowing the locations of suitable or preferred host trees (i.e., those larger in size). Nonhost volatiles, the alteration of soil composition, and overstory shade are discussed as potential explanatory factors for the patterns observed. New research avenues are suggested to determine whether nonhost vegetation in early successional stands might be an additional tool in the management of these insects in commercially important forests. PMID:19689899

  4. Origin of monoterpene emissions from boreal tree species: Determination of de novo and pool emissions by 13CO2 labeling

    Science.gov (United States)

    Rinne, J.; Ghirardo, A.; Koch, K.; Taipale, R.; Zimmer, I.; Schnitzler, J.

    2009-12-01

    Boreal forests emit a large amount of monoterpenes into the atmosphere. Traditionally these emissions are assumed to originate as evaporation from large storage pools. Thus their diurnal cycle would depend mostly on temperature. However, there is indication that a significant part of the monoterpene emission would originate directly from de novo synthesis. By applying 13CO2 fumigation and analyzing the isotope fractions with proton transfer reaction mass spectrometry (PTR-MS) and classical GC-MS we studied the origin of monoterpene emissions from some major Eurasian boreal and alpine tree species. We determined the fractions originating from de novo biosynthesis and from large internal monoterpene storages for three coniferous tree species with specialized monoterpene storage structures and one dicotyledon species without such structures. The emission from dicotyledon species Betula pendula originated solely from the de novo synthesis. The origin of the emissions from coniferous species was mixed with varying fraction originating from de novo synthesis (Pinus sylvestris 58%, Picea abies 33.5%, Larix decidua 9.8%) and the rest from large internal monoterpene storage pools. Application of the observed fractions of emission originating from de novo synthesis and large storage pools in a hybrid emission algorithm resulted in a better description of ecosystem scale monoterpene emissions from a boreal Scots pine forest stand.

  5. Effects of acidity on tree pollen germination and tube growth

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, J.S.; Van Rye, D.M.; Lassoie, J.P.

    1985-01-01

    Several studies have indicated that pollen germination and tube growth are adversely affected by air pollutants. Pollutants may inhibit the function of pollen by reducing the number of pollen grains which germinate, by reducing the maximum length to which the pollen tubes grow, or by interfering with the formation of the generative cell. The paper reports on studies that are attempting to determine the effects acid rain may have on these crucial stages in the life histories of northeastern tree species. The first stage of this work assessed the effects of acidity in the growth medium on in vitro pollen germination for four deciduous forest species common to central New York State, Betula lutea (yellow birch), B. lenta (black birch), Acer saccharum (sugar maple), and Cornus florida (flowering dogwood). Measurements were taken at the end of the growth period to determine the percentage of grains which had germinated, and to estimate the average tube length. To determine the effects of pollen on the growth medium, the pH of the germination drop was measured at the end of the growth period.

  6. 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.

  7. 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.

  8. 贵州西部4种林型土壤有机碳及其剖面分布特征%Soil organic carbon and its distribution characteristics in the soil profile for four forest types in west Guizhou

    Institute of Scientific and Technical Information of China (English)

    丁访军; 高艳平; 周凤娇; 潘明亮; 吴鹏

    2012-01-01

    The carbon bank of the forest soil has become one of the key research subjects concerning global carbon cycle in the context of global climate change. Taking the 4 major forest types in West Guizhou composed of Betula luminifera, Cryptomeria fortunei, Pinus armandii and Cunninghamia lanceolata as the research subjects, this paper studied the organic carbon contents of the soil, the density and the vertical distribution characteristics of the organic carbon. The results indicated that the organic carbon contents in the forests of Pinus armandii, Cunninghamia lanceolata, Cryptomeria fortunei and Betula luminifera were respectively 51.09 g·kg-1, 39.47 g·kg-1, 37.49 g·kg-1, 36.31 g·kg-1 and the carbon density was respectively 30.56 kg·m-2, 22.97 kg·m-2, 21.00 kg·m-2 and 20.13 kg·m-2, uniformly showing the descending order that Pinus arma·ndii > Cunninghamia lanceolata > Cryptomeria fortune > Betula luminifera, and the organic carbon contents as well as the carbon density of the soil in the forest of Pinus armandii were strikingly greater than those of the other 3 forests, among which the difference was not so distinct. Both the organic carbon contents and carbon density of the soil decreased gradually with the deepening of the soil in all the 4 forests and the organic carbon contents were the highest in the 0~10 cm-deep soil, as 1.45-1.61 times high as the average values of the whole soil profile, while the carbon densities in the 0-20 cm-deep soil accounted for 32.69% ~ 38.08% of the whole soil profile, prominently higher than those of the other soil depths. The carbon densities between different soil depths from below 20 cm-deep soil did not differ so much, and such characteristics indicated the soil carbon was more or less concentrating on the surface of the soil. For all the 4 forest types, there were strong negative correlations between the soil carbon contents and the pH values of the soil, and strong positive correlations between the soil carbon

  9. 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 Plantago major, and Deschampsia flexuosa. PMID:22789654

  10. 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.

  11. НЕЛИНЕЙНЫЕ МОДЕЛИ ВЗАИМОСВЯЗИ РАСПРОСТРАНЕНИЯ INONOTUS OBLIQUUS (PERS.) PIL. С БОНИТЕТОМ И ВОЗРАСТОМ БЕРЕЗОВОГО ЛЕСА. ВЛИЯНИЕ РЯДА МОРФОЛОГИЧЕСКИХ ХАРАКТЕРИСТИК НАСАЖДЕНИЙ НА ВСТРЕЧАЕМОСТЬ БАЗИДИАЛЬНОГО МАКРОМИЦЕТА

    OpenAIRE

    Баландайкин, М.

    2013-01-01

    Показаны регрессии двух параметров таксации на пространственную организацию факультативного сапротрофа в насаждениях Betula pendula Roth. Рассмотрены особенности влияния некоторых биоэкологических факторов на миграцию гриба.

  12. РАСПРОСТРАНЕНИЕ МАКРОМИЦЕТА INONOTUS OBLIQUUS (PERS.) PIL. В БЕРЕЗОВЫХ НАСАЖДЕНИЯХ РАЗЛИЧНОГО ПРОИСХОЖДЕНИЯ

    OpenAIRE

    Баландайкин, М.

    2013-01-01

    Позиционируется элементарная березовая синузия автотрофно детерминируемой консорции, разобщенная в констелляции по сингулярному таксационному признаку (происхождение древостоя) в аспекте импактивности Betula pendula Roth. скошенным трутовиком.

  13. Home ranges and habitat vegetation characters in breeding season of Narcissus Flycatcher and Yellow-rumped Flycatcher

    Institute of Scientific and Technical Information of China (English)

    WANG Ning; ZHANG Yanyun; ZHENG Guangmei

    2007-01-01

    The home ranges of the Narcissus Flycatcher (Ficedula narcissina elisae) and the Yellow-rumped Flycatcher (F.zanthopygia) are measured by radio telemetry in a subalpine forest near Beijing,China.The home range is calculated by 100% Minimum Convex Polygon (MCP),and the area varies from 2,000 to 5,000 m2.The majority of flycatchers can be found in the bottom of valleys and the underside of mountains.It is fairly rare for both Flycatcher species to leave their nests more than 70 m.Individuals of the species in pair-banding and nest-detecting periods have larger home ranges than those in incubation and rearing periods.The levels of canopy coverage in the home ranges of Narcissus Flycatchers are significantly higher than that of Yellowrumped Flycatchers.There are also more tall trees and stumps in the home ranges of Narcissus Flycatchers than in that of Yellow-rumped Flycatchers.The dominant tree species in the home ranges of Narcissus Flycatchers is Dahurian Birch (Betula dahurica),whereas Manchurian Walnut (Juglans mandshurica) is the dominant tree species in the home ranges of Yellow-rumped Flycatchers.

  14. Scale correlation between vegetation and soil in larch forest, NE China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    After the analysis on the linages of species, the fractal dimensions of vegetation and soil in a managed larch(Larix gmelini) forest in Daxingan Mountains, NE China were estimated separately, and their scale correlation was discussed. (1) The dominant species of the larch forest, larch and the important accompany species, birch(Betula platyphylla) were homogeneously distributed along the transect. The other species were heterogeneous, and can be divided into three groups located on the right , left and central parts of th transect respectively. The transect can be separated into two parts at the position for the 29th quadrat(580m). (2) The fractal dimension in the large scale range from 200 to 400m was lower than that in the small scale range from 0 to 200m in the forest, indicating the different variation regularities of spatial heterogeneity in different scale ranges. The inflection point at 200m was one of the key scales of spatial hierarchy of the larch forest. (3) The scale variation of the forest was correlated with that of soil pH on large scales, which reflected the indirect control of the dominant species to the spatial pattern and species distribution of understories by changing soil acidity in the forest and the indirect effects of forest management.

  15. Diversity, Distribution Pattern and Conservation Status of the Plants Used in Liver Diseases/Ailments in Indian Himalayan Region

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In the Indian Himalayan Region, the studies focused on diversity of the plants used for treating liver diseases/ailments have not been carried out so far. Therefore, the present attempt has been made to study the diversity, distribution patternand conservation status of the plant species used for treating liver diseases/ailments in that region. A total of 138 species (35 species of trees, 22 shrubs and 81 herbs) belonging to 98 genera in 60 families have been recorded. Amongst the families, Euphorbiaceae (9 species), and altitudinal zone <1,800 m, (i.e., 115species) are rich in species. Traditionally, various plant parts, such as roots/rhizomes/tubers (46species), leaves (31), whole plants (30), barks (15),fruits (13), seeds and unspecified parts (8 each), and inflorescence (1) are used for the treatment of liver diseases/ailments. 34 species are native, 3 are endemic and 15 near endemic. 7 species are categorized as Critically Endangered (Betula utilis),Endangered (Podophyllum hexandrum, Ephedra gerardiana, and Nardostachys grandiflora) and Vulnerable (Bergenia ligulata, B. stracheyi, and Hedychium spicatum) using new IUCN criteria.Available chemical composition of plant parts used for the treatment of liver diseases/ailments have been given. Assessment of the populations of threatened species, development of an appropriate strategy,action plan for the conservation and sustainable utilization of such components of plant diversity are suggested.

  16. Spatial variations of Pb in the vertical zone of the soil-plant system in the Changbai Mountain National Nature Reserve

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The characteristics of vertical and horizontal variations of lead element(Pb) in soil-plant system of vertical zone in Changbai Mountain National Nature Reserve(CNNR) were studied.The results showed that Pb concentrations in soils of vertical zone are all above 25 mg/kg,and the average Pb concentration of each soil zone negatively correlates its degree of variation,i.e.brown coniferous forest soil zone has the lowest average Pb concentration of four soil zones,and the highest horizontal variation; however,mountain soddy forest soil has the highest average Pb concentration,and the lowest horizontal variation; the average concentration of plant Pb of each plant zone is lower than the worldwide average level of Pb in plant( Clarke),respectively,and plant Pb content order is consistent with soil Pb content order,but their horizontal variations are different from those in soil zones,the variation of mountain tundra forest zone is highest,but Betula ermanii forest zone the lowest.Vertical variation of plant Pb is obviously higher than that in soils with variation coefficient of 89.76%; the enrichment capability of plant for Pb is depended on the plant types and the different organs of plant; parent material and parent rock,pH values,soil organic matter and soil particle fraction etc.are the main factors influencing variations of Pb content in soil-plant system of vertical zone in CNNR.

  17. 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.

  18. Non-destructive methods for peat layer assessment in oligotrophic peat bogs: a case study from Poiana Ştampei, Romania

    Directory of Open Access Journals (Sweden)

    Iuliana F. Gheorghe

    2011-04-01

    Full Text Available Practices currently employed in the investigation and characterisation of peat deposits are destructive and may irremediable perturb peat bog development even in cases when exploitation is not carried out. We investigated the correlation between vegetation characteristics in the active area of Poiana Ştampei peat bog, Romania, and the underlying peat layer depth, aiming at establishing a non-destructive method of peat layer depth estimation. The presence of the Sphagneto-Eriophoretum vaginati association, dominated by Sphagnum fimbriatum, Eriophorum vaginatum, Andromeda polifolia, Vaccinium oxycoccos, V. myrtillus, V. vitis-idaea, Polytrichum commune, Picea excelsa, Pinus sylvestris and Betula verrucosa was found to predict the existence of the peat layer but not its depth. Out of the seven identified vegetation types, one type was associated with a very thin or no peat layer, one type was characterised by the presence of a thick (over 100 cm peat layer and five types indicated the presence of variable average depths of the peat layer. pH values correlated with peat layer depth only within the vegetation type associated with thick peat layers.

  19. Root biomass and underground C and N storage of the primitive Korean pine and broad-leaved forest and its different succession stages in Changbai Mountain, northeast China

    Institute of Scientific and Technical Information of China (English)

    YANG Liyun; LUO Tianxiang; WU Songtao

    2006-01-01

    This paper studied root biomass and underground carbon (C) and nitrogen (N) storage of a more than 200-year-old primitive Korean pine and broad-leaved forest and its two 20- and 80-year-old secondary Populus davidiana and Betula platyphylla forests in Changbai Mountain,northeast China.The results showed that with forest succession,the root biomass of 20-year-old,80-year-old,and primitive forests was 2.437,2.742,and 4.114 kg/m2,respectively.The root C storage was 1.113,1.323,and 2.023kg/m2,soil C storage was 11.911,11.943,and 12.587 kg/m2,and underground C storage was 13.024,13.266,and 14.610kg/m2,respectively,while the root N storage was 0.035,0.032,and 0.038 kg/m2,soil N storage was 1.208,1.222,and 0.915 kg/m2,and underground N storage was 1.243,1.254,and 0.955 kg/m2,respectively,which indicated that along with forest succession,the forest underground became a potential"carbon sink,"whereas underground N storage did not change obviously.

  20. Ten newly recorded species of spermatophyte in Hunan Province%10种湖南省种子植物新记录种

    Institute of Scientific and Technical Information of China (English)

    周建军; 周电; 黎明; 周辉; 刘应志; 喻勋林

    2015-01-01

    记述了湖南省种子植物分布新纪录种10种。这些新记录种隶属于7科、10属,分别是山卷耳、思茅厚皮香、迎春樱桃、西桦、嵩明省沽油、山东万寿竹、海南蜘蛛抱蛋、广西柳叶箬、蛊羊茅、卵花甜茅等。%Ten species of spermatophyte reported for the first time in Hunan Province are newly recorded,which belong to seven families and ten genera.including Cerastium pusillum Ser.,Ternstroemia simaoensis L.K.Ling,Cerasus dis-coidea Yu et Li ,Betula alnoides Buch.-Ham.ex D.Don,Staphylea forrestii Balf.f.,Disporum smilacina A.Gray , Aspidistra hainanensis W.Y.Chun &F.C.How ,Isachne guangxiensis W.Z.Fang ,Festuca fascinata Keng ex S.L. Lu ,Glyceria tonglensis C.B.Clarke.

  1. The effect of fire disturbance on short-term soil respiration in typical forest of Greater Xing’an Range, China

    Institute of Scientific and Technical Information of China (English)

    Long Sun; Tongxin Hu; Ji Hong Kim; Futao Guo; Hong Song; Xinshuang Lv; Haiqing Hu

    2014-01-01

    We investigated the effect of fire disturbance on short-term soil respiration in birch (Betula platyphylla Suk.) and larch (Larix gmelinii Rupr.) forests in Greater Xing’an range, northeastern China for further understanding of its effect on the carbon cycle in ecosystems. Our study show that post-fire soil respiration rates in B. platyphylla and L. gmelinii forests were reduced by 14%and 10%, respectively. In contrast, the soil heterotrophic respiration rates in the two types of forest were similar in post-fire and control plots. After fire, the contribution of root respiration to total soil respiration was dramatically reduced. Variation in soil respiration rates was explained by soil moisture (W) and soil tem-perature (T) at a depth of 5 cm. Exponential regression fitted T and W models explained Rs rates in B. platyphylla control and post-fire plots (83.1% and 86.2%) and L. gmelinii control and post-fire plots (83.7%and 88.7%). In addition, the short-term temperature coefficients in B.

  2. Boreal Forests of Kamchatka: Structure and Composition

    Directory of Open Access Journals (Sweden)

    Markus P. Eichhorn

    2010-09-01

    Full Text Available Central Kamchatka abounds in virgin old-growth boreal forest, formed primarily by Larix cajanderi and Betula platyphylla in varying proportions. A series of eight 0.25–0.30 ha plots captured the range of forests present in this region and their structure is described. Overall trends in both uplands and lowlands are for higher sites to be dominated by L. cajanderi with an increasing component of B. platyphylla with decreasing altitude. The tree line on wet sites is commonly formed by mono-dominant B. ermanii forests. Basal area ranged from 7.8–38.1 m2/ha and average tree height from 8.3–24.7 m, both being greater in lowland forests. Size distributions varied considerably among plots, though they were consistently more even for L. cajanderi than B. platyphylla. Upland sites also contained a dense subcanopy of Pinus pumila averaging 38% of ground area. Soil characteristics differed among plots, with upland soils being of lower pH and containing more carbon. Comparisons are drawn with boreal forests elsewhere and the main current threats assessed. These forests provide a potential baseline to contrast with more disturbed regions elsewhere in the world and therefore may be used as a target for restoration efforts or to assess the effects of climate change independent of human impacts.

  3. The skin prick test – European standards

    Directory of Open Access Journals (Sweden)

    Heinzerling Lucie

    2013-02-01

    Full Text Available Abstract Skin prick testing is an essential test procedure to confirm sensitization in IgE-mediated allergic disease in subjects with rhinoconjunctivitis, asthma, urticaria, anapylaxis, atopic eczema and food and drug allergy. This manuscript reviews the available evidence including Medline and Embase searches, abstracts of international allergy meetings and position papers from the world allergy literature. The recommended method of prick testing includes the appropriate use of specific allergen extracts, positive and negative controls, interpretation of the tests after 15 – 20 minutes of application, with a positive result defined as a wheal ≥3 mm diameter. A standard prick test panel for Europe for inhalants is proposed and includes hazel (Corylus avellana, alder (Alnus incana, birch (Betula alba, plane (Platanus vulgaris, cypress (Cupressus sempervirens, grass mix (Poa pratensis, Dactilis glomerata, Lolium perenne, Phleum pratense, Festuca pratensis, Helictotrichon pretense, Olive (Olea europaea, mugwort (Artemisia vulgaris, ragweed (Ambrosia artemisiifolia, Alternaria alternata (tenuis, Cladosporium herbarum, Aspergillus fumigatus, Parietaria, cat, dog, Dermatophagoides pteronyssinus, Dermatophagoides farinae, and cockroach (Blatella germanica. Standardization of the skin test procedures and standard panels for different geographic locations are encouraged worldwide to permit better comparisons for diagnostic, clinical and research purposes.

  4. The occurence of rare and protected plant species on the peat bog near Lake Bikcze (Łęczyńsko-Włodawskie Lakeland

    Directory of Open Access Journals (Sweden)

    Magdalena Pogorzelec

    2012-12-01

    Full Text Available This paper presents the results of a pilot field study, conducted in July 2007, designed to make floristic evaluation of the peat bog area adjacent to the western shore of Lake Bikcze (Łęczyńsko-Włodawskie Lakeland. The main aim of the study was to confirm the occurrence of populations of rare and legally protected plant species in this area and to identify, on a preliminary basis, habitat conditions in their stands. The occurrence of populations of the following strictly protected plant species: Betula humilis, Salix lapponum, Salix myrtilloides, Carex limosa, Drosera intermedia, Drosera rotundifolia, Dactylorhiza incarnata; and partially protected species: Menyanthes trifoliata, has been confirmed in the studied peat bog. Both an investigation of abiotic factors, conducted in situ, and an analysis of the species composition of the flora in terms of habitat preferences of particular groups of taxa have shown that the described rare plant species find suitable conditions for their growth and development in the studied peat bog.

  5. Belowground carbon pools and dynamics in China's warm temperate and sub-tropical deciduous forests

    Directory of Open Access Journals (Sweden)

    C. W. Xiao

    2009-07-01

    Full Text Available We report the first estimates of pools and dynamics of microbes, roots, plant litter and soil organic carbon (SOC in three dominant types of China's vast deciduous forest area: Betula platyphylla, Quercus liaotungensis, and Quercus aliena varacuteserrata. Organic matter degradation rates overshadowed litter inputs as the main determinant of the soil carbon stocks. Across the three forests, rates of litter decomposition were also indicative for turnover rates of SOC. Litter and SOC decay was faster in the sub-tropical than in the warm-temperate forests. Among the latter, SOC turnover was highest in the forest producing the higher-quality litter. Microbial biomass was, as expected, correlated with SOC content. Microbial activity, in contrast, was highest at the sub-tropical forest, despite the lower SOC availability, lower fraction of labile SOC, and lower soil microbial biomass. These results may contribute to increased understanding of controls over belowground carbon cycling in deciduous forests.

  6. Large ontogenetic declines in intra-crown leaf area index in two temperate deciduous tree species.

    Science.gov (United States)

    Nock, C A; Caspersen, J P; Thomas, S C

    2008-03-01

    The widespread occurrence of age-related changes in leaf morphology and allocation suggests that the leaf area index of individual trees (intra-crown LAI) may decline late in ontogeny. We used direct, within-canopy measurements to quantify the LAI of canopy trees with exposed crowns of two temperate deciduous species. Intra-crown LAI declined from approximately 7 to 4 in Acer saccharum, and from approximately 9.5 to 6.5 in Betula alleghaniensis, as tree size increased (from 15 to 72 cm diameter at breast height [dbh]). For A. saccharum, age (which varied from 30 to 160 years) was a significantly better predictor of LAI decline than dbh. We also modeled the effect of ontogenetic declines in LAI on understory light availability and found that light transmission increases significantly as canopy trees grow and mature. Our results thus suggest that gradual declines in LAI with tree age may play an important and overlooked role in contributing to the heterogeneity of sub-canopy light regimes in mature forests. PMID:18459337

  7. Canopy carbon net assimilation of an urban, naturally assembled brownfield forest

    Science.gov (United States)

    Schafer, K. V.; Wadhwa, S.; Tripathee, R.; Gallagher, F. J.

    2010-12-01

    In this study, we have been investigating an urban brownfield at Liberty State Park that has been abandoned approximately for 40 years. Natural colonization has taken place that allowed a pioneer forest to grow with primarily Betula populifera and Populus spec. Despite soil metal contamination this urban forest exhibits moderate annual productivity and serves as a carbon sink. Diameters at breast height (DBH, 1.35 m above ground) of all trees in a study plot were measured. Aboveground biomass equations were determined for both species through destructive sampling. Aboveground net primary production was about 770 gC m-2 a-1 in 2009. Canopy net assimilation (AnC) was modeled with the canopy conductance constrained assimilation (4CA) model using measured sapflux derived conductance and photosynthetic parameters measured with a LICOR 6400. Annual AnC in 2009 was approximately 1500 gC m-2 a-1 thus with a partitioning of biomass and respiration in the same range of most natural forest with less anthropogenic induced stress. Urban brownfields thus can serve as C sinks and provide phytostabilization of contaminants.

  8. The Pleistocene biogeography of eastern North America: A nonmigration scenario for deciduous forest

    Energy Technology Data Exchange (ETDEWEB)

    Loehle, C. [Argonne National Lab., IL (United States). Environmental Research Div.; Iltis, H. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Botany

    1998-12-31

    The current reconstruction of the vegetation of eastern North America at the last glacial maximum postulates a very wide zone of tundra and boreal forest south of the ice. This reconstruction requires that the deciduous forest retreated far to the south. The authors believe that this reconstruction is seriously in error. Geologic evidence for glacial activity or tundra is absent from the southern Appalachians. Positive evidence for boreal forest is based on pollen identifications for Picea, Betula, and Pinus, when in reality southern members of these genera have pollen that cannot be distinguished from that of northern members. Further, pollen of typical southern species such as oaks and hickories occurs throughout profiles that past authors had labeled boreal. Pollen evidence for a far southern deciduous forest refuge is lacking. Data on endemics are particularly challenging for the scenario in which deciduous forest migrated to the south and back. The southern Appalachian region is rife with endemics that are often extreme-habitat specialists unable to migrate. The previously glaciated zone is almost completely lacking in endemics. Outlier populations, range boundaries, and absence of certain hybrids all argue against a large boreal zone. The new reconstruction postulates a cold zone no more than 75--100 miles wide south of the ice in the East.

  9. [Temperature sensitivity of soil organic carbon mineralization and β-glucosidase enzymekinetics in the northern temperate forests at different altitudes, China].

    Science.gov (United States)

    Fan, Jin-juan; Li, Dan-dan; Zhang, Xin-yu; He, Nian-peng; Bu, Jin-feng; Wang, Qing; Sun, Xiao-min; Wen, Xue-fa

    2016-01-01

    Soil samples, which were collected from three typical forests, i.e., Betula ermanii forest, coniferous mixed broad-leaved forest, and Pinus koraiensis forest, at different altitudes along the southern slope of Laotuding Mountain of Changbai Mountain range in Liaoning Province of China, were incubated over a temperature gradient in laboratory. Soil organic carbon mineralization rates (Cmin), soil β-1,4-glucosidase (βG) kinetics and their temperature sensitivity (Q₁₀) were measured. The results showed that both altitude and temperature had significant effects on Cmin · Cmin increased with temperature and was highest in the B. ermanii forest. The temperature sensitivity of Cmin [Q₁₀(Cmin)] ranked in order of B. ermanii forest > P. koraiensis forest > coniferous mixed broad-leaved forest, but did not differ significantly among the three forests. Both the maximum activity (Vmax) and the Michaelis constant (Km) of the βG responded positively to temperature for all the forests. The temperature sensitivity of Vmax [Q₁₀(Vmax)] ranged from 1.78 to 1.90, and the temperature sensitivity of Km [Q₁₀(Km)] ranged from 1.79 to 2.00. The Q₁₀(Vmax)/Q10(Km) ratios were significantly greater in the B. ermanii soil than in the other two forest soils, suggesting that the βG kinetics-dependent impacts of the global warming or temperature increase on the decomposition of soil organic carbon were temperature sensitive for the forests at the higher altitudes.

  10. Mechanism Underlying the Spatial Pattern Formation of Dominant Tree Species in a Natural Secondary Forest.

    Directory of Open Access Journals (Sweden)

    Guodong Jia

    Full Text Available Studying the spatial pattern of plant species may provide significant insights into processes and mechanisms that maintain stand stability. To better understand the dynamics of naturally regenerated secondary forests, univariate and bivariate Ripley's L(r functions were employed to evaluate intra-/interspecific relationships of four dominant tree species (Populus davidiana, Betula platyphylla, Larix gmelinii and Acer mono and to distinguish the underlying mechanism of spatial distribution. The results showed that the distribution of soil, water and nutrients was not fragmented but presented clear gradients. An overall aggregated distribution existed at most distances. No correlation was found between the spatial pattern of soil conditions and that of trees. Both positive and negative intra- and interspecific relationships were found between different DBH classes at various distances. Large trees did not show systematic inhibition of the saplings. By contrast, the inhibition intensified as the height differences increased between the compared pairs. Except for Larix, universal inhibition of saplings by upper layer trees occurred among other species, and this reflected the vertical competition for light. Therefore, we believe that competition for light rather than soil nutrients underlies the mechanism driving the formation of stand spatial pattern in the rocky mountainous areas examined.

  11. Factors influencing caesium-137 levels in moose (Alces alces) and small game in Northern Sweden

    International Nuclear Information System (INIS)

    In the third annual hunting season after the Chernobyl accident the concentration of Cs-137 in meat of northern Swedish moose was significantly higher than in the first one (1986). In September 1986 the mean Cs concentration was 500 Bq/kg in calves but in September 1988 it has risen 1300 Bq/kg. This increase was only temporary and a rapid decline occured after September and by December 1988 the concentration of Cs was the same as in late 1986. Adult moose showed the same increase during the hunt 1988 but to a lower magnitude. Typical food plants of moose such as bilberry (Vaccinum myrtillus) and birch (Betula pubescens) showed, contradictory to expected by the level in moose, a decline of concentration caesium from 1986 to 1988. A probable explanation to the dramatically increased concentration of Cs in moose is a change in diet selection during 1988. Small mammals such as voles and lemmings showed a variation in concentration of caesium-137 which was more dependent on other factors than on their body size. This emphasize the necessity to study diet selection by herbivores in detail in order to predict uptake and changes in environmental contaminants. (orig.)

  12. ALPINE VEGETATION ECOTONE DYNAMICS IN GANGOTRI CATCHMENT USING REMOTE SENSING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    C. P. Singh

    2012-09-01

    Full Text Available Analysis of the satellite imagery reveals two different perspectives of the vegetation ecotone dynamics in Gangotri catchment. On one hand, there is evidence of upward shift in the alpine tree and vegetation ecotone over three decades. On the other hand, there has been densification happening at the past treeline. The time series fAPAR data of two decades from NOAA-AVHRR confirms the greening trend in the area. The density of trees in Chirbasa has gone up whereas in Bhojbasa there is no significant change in NDVI but the number of groves has increased. Near Gaumukh the vegetal activity has not shown any significant change. We found that the treeline extracted from satellite imagery has moved up about 327±80m and other vegetation line has moved up about 401±77m in three decades. The vertical rate of treeline shift is found to be 11m/yr with reference to 1976 treeline; however, this can be 5m/yr if past toposheet records (1924 – 45 are considered as reliable reference. However, the future IPCC scenario based bioclimatic fundamental niche modelling of the Betula utilis (a surrogate to alpine treeline suggests that treeline could be moving upward with an average rate of 3m/yr. This study not only confirms that there is an upward shift of vegetation in the alpine zone of Himalayas, but also indicate that old vegetation ecotones have grown denser

  13. Effects of invasive European bird cherry (Prunus padus) on leaf litter processing by aquatic invertebrate shredder communities in urban Alaskan streams

    Science.gov (United States)

    Roon, David A.; Wipfli, Mark S.; Wurtz, Tricia L.

    2014-01-01

    European bird cherry (Prunus padus) (EBC) is an invasive ornamental tree that is spreading rapidly in riparian forests of urban Alaska. To determine how the spread of EBC affects leaf litter processing by aquatic invertebrate shredders, we conducted complementary leaf pack experiments in two streams located in Anchorage, Alaska. The first experiment contrasted invasive EBC with three native tree species—thin-leaf alder (Alnus tenuifolia), paper birch (Betula neoalaskana), and black cottonwood (Populus trichocarpa)—in one reach of Chester Creek; finding that EBC leaf litter broke down significantly faster than birch and cottonwood, but at a similar rate to alder. The second experiment contrasted EBC with alder in four reaches of Campbell and Chester creeks; finding that while EBC leaf litter broke down significantly faster than alder in Chester Creek, EBC broke down at a similar rate to alder in Campbell Creek. Although EBC sometimes supported fewer shredders by both count and mass, shredder communities did not differ significantly between EBC and native plants. Collectively, these data suggest that invasive EBC is not currently exhibiting strong negative impacts on leaf litter processing in these streams, but could if it continues to spread and further displaces native species over time.

  14. 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.

  15. Late Glacial and Early Holocene Climatic Changes Based on a Multiproxy Lacustrine Sediment Record from Northeast Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Kokorowski, H D; Anderson, P M; Sletten, R S; Lozhkin, A V; Brown, T A

    2008-05-20

    Palynological (species assemblage, pollen accumulation rate), geochemical (carbon to nitrogen ratios, organic carbon and biogenic silica content), and sedimentological (particle size, magnetic susceptibility) data combined with improved chronology and greater sampling resolution from a new core from Elikchan 4 Lake provide a stronger basis for defining paleoenvironmental changes than was previously possible. Persistence of herb-dominated tundra, slow expansion of Betula and Alnus shrubs, and low percentages of organic carbon and biogenic silica suggest that the Late-Glacial transition (ca. 16,000-11,000 cal. yr BP) was a period of gradual rather than abrupt vegetation and climatic change. Consistency of all Late-Glacial data indicates no Younger Dryas climatic oscillation. A dramatic peak in pollen accumulation rates (ca. 11,000-9800 cal. yr BP) suggests a possible summer temperature optimum, but finer grain-sizes, low magnetic susceptibility, and greater organic carbon and biogenic silica, while showing significant warming at ca. 11,000 cal. yr BP, offer no evidence of a Holocene thermal maximum. When compared to trends in other paleo-records, the new Elikchan data underscore the apparent spatial complexity of climatic responses in Northeast Siberia to global forcings between ca. 16,000-9000 cal. yr BP.

  16. Response of seedlings of different tree species to elevated C02 in Changbai Mountain

    Institute of Scientific and Technical Information of China (English)

    DAILi-min; JILan-zhu; WANGMiao; LIQiu-rong

    2003-01-01

    Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Lanx olgensis,Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadleaved/Korean pine forest, to elevated CO2 were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998-1999). Two concentrations of CO2 were designed: elevated CO2 (700 pmol· mol-1) and ambient CO2 (400μmol· mol-1). The study results showed that the height growth of the tree seedlings grown at elevated CO2 increased by about 10%-40% compared to those grown at ambient CO2. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration and chlorophyll content to elevated CO2 varied with tree species.The broad-leaf tree species were more sensitive to the elevated CO2than conifer tree species. All seedlings showed a photo-synthetic acclimation to Iong-term elevated CO2.

  17. Drought and shade deplete nonstructural carbohydrate reserves in seedlings of five temperate tree species.

    Science.gov (United States)

    Maguire, Andrea J; Kobe, Richard K

    2015-12-01

    Plants that store nonstructural carbohydrates (NSC) may rely on carbon reserves to survive carbon-limiting stress, assuming that reserves can be mobilized. We asked whether carbon reserves decrease in resource stressed seedlings, and if NSC allocation is related to species' relative stress tolerances. We tested the effects of stress (shade, drought, and defoliation) on NSC in seedlings of five temperate tree species (Acer rubrum Marsh., Betula papyrifera Marsh., Fraxinus americana L ., Quercus rubra L., and Quercus velutina Lam.). In a greenhouse experiment, seedlings were subjected to combinations of shade, drought, and defoliation. We harvested seedlings over 32-97 days and measured biomass and NSC concentrations in stems and roots to estimate depletion rates. For all species and treatments, except for defoliation, seedling growth and NSC accumulation ceased. Shade and drought combined caused total NSC decreases in all species. For shade or drought alone, only some species experienced decreases. Starch followed similar patterns as total NSC, but soluble sugars increased under drought for drought-tolerant species. These results provide evidence that species deplete stored carbon in response to carbon limiting stress and that species differences in NSC response may be important for understanding carbon depletion as a buffer against shade- and drought-induced mortality.

  18. Soil propagule banks of ectomycorrhizal fungi share many common species along an elevation gradient.

    Science.gov (United States)

    Miyamoto, Yumiko; Nara, Kazuhide

    2016-04-01

    We conducted bioassay experiments to investigate the soil propagule banks of ectomycorrhizal (EM) fungi in old-growth forests along an elevation gradient and compared the elevation pattern with the composition of EM fungi on existing roots in the field. In total, 150 soil cores were collected from three forests on Mt. Ishizuchi, western Japan, and subjected to bioassays using Pinus densiflora and Betula maximowicziana. Using molecular analyses, we recorded 23 EM fungal species in the assayed propagule banks. Eight species (34.8 %) were shared across the three sites, which ranged from a warm-temperate evergreen mixed forest to a subalpine conifer forest. The elevation pattern of the assayed propagule banks differed dramatically from that of EM fungi on existing roots along the same gradient, where only a small proportion of EM fungal species (3.5 %) were shared across sites. The EM fungal species found in the assayed propagule banks included many pioneer fungal species and composition differed significantly from that on existing roots. Furthermore, only 4 of 23 species were shared between the two host species, indicating a strong effect of bioassay host identity in determining the propagule banks of EM fungi. These results imply that the assayed propagule bank is less affected by climate compared to EM fungal communities on existing roots. The dominance of disturbance-dependent fungal species in the assayed propagule banks may result in higher ecosystem resilience to disturbance even in old-growth temperate forests. PMID:26231215

  19. The rhizosphere and PAH amendment mediate impacts on functional and structural bacterial diversity in sandy peat soil

    Energy Technology Data Exchange (ETDEWEB)

    Yrjaelae, Kim, E-mail: kim.yrjala@helsinki.f [Department of Biological and Environmental Sciences, General Microbiology, University of Helsinki, P.O. Box 56, (Biocenter 1C), 00014 Helsinki (Finland); Keskinen, Anna-Kaisa; Akerman, Marja-Leena; Fortelius, Carola [METROPOLIA University of Applied Science, Vantaa (Finland); Sipilae, Timo P. [Department of Biological and Environmental Sciences, General Microbiology, University of Helsinki, P.O. Box 56, (Biocenter 1C), 00014 Helsinki (Finland)

    2010-05-15

    To reveal the degradation capacity of bacteria in PAH polluted soil and rhizosphere we combined bacterial extradiol ring-cleavage dioxygenase and 16S rRNA analysis in Betula pubescens rhizoremediation. Characterisation of the functional bacterial community by RFLP revealed novel environmental dioxygenases, and their putative hosts were studied by 16S rRNA amplification. Plant rhizosphere and PAH amendment effects were detected by the RFLP/T-RFLP analysis. Functional species richness increased in the birch rhizosphere and PAH amendment impacted the compositional diversity of the dioxygenases and the structural 16S rRNA community. A shift from an Acidobacteria and Verrucomicrobia dominated to an Alpha- and Betaproteobacteria dominated community structure was detected in polluted soil. Clone sequence analysis indicated catabolic significance of Burkholderia in PAH polluted soil. These results advance our understanding of rhizoremediation and unveil the extent of uncharacterized functional bacteria to benefit bioremediation by facilitating the development of the molecular tool box to monitor bacterial populations in biodegradation. - The bacterial community analysis using 16S rRNA and extradiol dioxygenase marker genes in rhizoremediation revealed both a rhizosphere and a PAH-pollution effect.

  20. Evaluation of urban environment pollution based on the accumulation of macro- and trace elements in epiphytic lichens.

    Science.gov (United States)

    Parzych, Agnieszka; Astel, Aleksander; Zduńczyk, Anna; Surowiec, Tomasz

    2016-01-01

    Nitrogen, phosphorus, potassium, magnesium, zinc, nickel, copper, manganese, iron and lead accumulation properties of three epiphytic lichen species (Hypogymnia physodes (L.) Nyl., Parmelia sulcata Taylor and Xanthoria parietina (L.) Th. Fr.) were compared. An assessment of pollution of the municipal environment in Słupsk (Poland) according to macro- and trace elements was also done. Lichen samples were taken in Autumn 2013 from Betula pendula, Fraxinus excelsior, Acer platanoides, A. pseudoplatanus and Populus sp. trees. Sampling stations comprised of house development areas, green urban parks, vicinity of streets with heavy traffic and industrial enterprises. It was found that lichens represent diverse accumulation properties to pollutants according to the species. X. parietina indicated the highest bioaccumulation in relation to N, K, Mg, Zn and Fe, the thalli of H. physodes accumulated the largest amounts of Ni and Pb, while P. sulcata P and Cu. Manganese was accumulated in similar quantities by all species. Evidences acquired by the use of factor analysis proved that pollution in Słupsk municipal environment is a serious issue with three major sources domination: street dust, marine factor and residual oil combustion. The high-risk areas were detected and visualized using surface maps based on Kriging algorithm. It was seen that the highest pollution occurs in the town centre, while the smallest happened on its outskirts and in urban parks.

  1. Þéttleiki og fjölbreytileiki sveppróta í misgömlum birki og lerkiskógum

    OpenAIRE

    Brynja Hrafnkelsdóttir 1982

    2009-01-01

    Þéttleiki og fjölbreytileiki útrænnar svepprótar var rannsakaður í misgömlum birkiskógum (Betula pubescens) og lerkiskógum (Larix sibirica) á Fljótsdalshéraði, auk þess sem skóglaust mólendi var haft með til samanburðar. Leitað var svara við eftirfarandi spurningum: a) Er svepprótarsmit til staðar í skóglausu landi á Fljótsdalshéraði? b) Myndast svepprót á birkiplöntum ef þær eru gróðursettar í lerkiskóg? Myndast svepprót á lerkiplöntur ef þær eru gróðursettar í birkiskóg? c) Er hægt að no...

  2. Holocene grassland vegetation, climate and human impact in central eastern Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    HUANG; Fei; Kealhofer; Lisa; XIONG; Shangfa; HUANG; Fengb

    2005-01-01

    Phytolith and pollen preserved in the Taipusi Banner paleosol profile, central eastern Inner Mongolia, provide evidence of Holocene grassland vegetation, climate and human impact. The combined phytolith and pollen records reveal a major change in vegetation composition about 5000 a BP. Before 5000 a BP, the vegetation was dominated by Aneurolepidium chinese-Stipa grandis grassland of C4 grasses. After 5000 a BP, C4 grasses rapidly retreated,indicating a shift to colder and more arid conditions. The gradual invasion of Stipa krylovii, Agropyron desertorum, Ephedra, Chenopodiaceae and Caragana reveal the onset of grassland degeneration. Between 10000 and 8720 a BP, the Aneurolepidium chinese-Stipa grandis grassland included a small proportion of Artemisia shrub and Echionopos type plants, implying a strong winter monsoon and very weak summer monsoon. From 8720 to 7000 a BP, C4 grasses were common, indicating a strengthening of the summer monsoon. Between 7000 and 5000 a BP,the Holocene thermal maximum was evident, with a significant expansion of C4 grasses and the presence of some trees (such as Pinus and Betula, and so on) in or near the study site. From 4200-3000 a BP, a sandy grassland of Artemisia and Agropyron desertorum together with As ter-type taxa occurred. Precipitation amelioration took place between 3000 and 2170 a BP, with a rapid development of Echinops type plants and a small expansion of C4 grasses. From 2170 a BP to present, human activities accelerated the process of grassland degeneration.

  3. 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 (O2) and non-photorespiratory (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. PMID:17080940

  4. Influence of wind on daily airborne pollen counts in Catalonia (NE Iberian Peninsula)

    Science.gov (United States)

    tareq Majeed, Husam; Periago, Cristina; Alarcón, Marta; De Linares, Concepción; Belmonte, Jordina

    2016-04-01

    The aim of this study is to analize the influence of wind (speed and direction) on the daily airborne pollen counts recorded in Catalonia (NE Iberian Peninsula) of 21 pollen taxa recorded at 6 aerobiological stations: Barcelona, Bellaterra, Girona, Lleida Manresa, and Tarragona for the period 2004-2014. The taxa studied are Alnus, Betula, Castanea, Cupressaceae, Fagus, Fraxinus, Olea, Pinus, Platanus, total Quercus, Quercus deciduous type, Quercus evergreen type, Ulmus, Corylus, Pistacia, Artemisia, Chenopodiaceae/Amaranthaceae, Plantago, Poaceae, Polygonaceae, and Urticaceae. The mean daily wind direction was divided into 8 sectors: N, NE, E, SE, S, SW, W and NW. For each sector, the correlation between the daily pollen concentrations and wind speed using Spearman's rank correlation coefficient was computed and compared with the wind rose charts. The results showed that Tarragona was the station with more significant correlations followed by Bellaterra, Lleida and Manresa. On the other hand, Artemisia was the most correlated taxon with mainly negative values, and Fagus was the least. The W wind direction showed the largest number of significant correlations, mostly positive, while the N direction was the least and negatively correlated.

  5. Mechanism Underlying the Spatial Pattern Formation of Dominant Tree Species in a Natural Secondary Forest.

    Science.gov (United States)

    Jia, Guodong; Yu, Xinxiao; Fan, Dengxing; Jia, Jianbo

    2016-01-01

    Studying the spatial pattern of plant species may provide significant insights into processes and mechanisms that maintain stand stability. To better understand the dynamics of naturally regenerated secondary forests, univariate and bivariate Ripley's L(r) functions were employed to evaluate intra-/interspecific relationships of four dominant tree species (Populus davidiana, Betula platyphylla, Larix gmelinii and Acer mono) and to distinguish the underlying mechanism of spatial distribution. The results showed that the distribution of soil, water and nutrients was not fragmented but presented clear gradients. An overall aggregated distribution existed at most distances. No correlation was found between the spatial pattern of soil conditions and that of trees. Both positive and negative intra- and interspecific relationships were found between different DBH classes at various distances. Large trees did not show systematic inhibition of the saplings. By contrast, the inhibition intensified as the height differences increased between the compared pairs. Except for Larix, universal inhibition of saplings by upper layer trees occurred among other species, and this reflected the vertical competition for light. Therefore, we believe that competition for light rather than soil nutrients underlies the mechanism driving the formation of stand spatial pattern in the rocky mountainous areas examined. PMID:27028757

  6. Research on dynamics of tundra ecosystems and their potential response to energy resource development. Progress report, May 1, 1978-April 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Miller, P.C.

    1979-01-01

    The ecological effects (costs and benefits) of impacts that can be expected from the development and utilization of energy resources in the arctic. The impacts selected for study are: altered nutrient availability (nitrogen and phosphorus); altered patterns of soil water drainage; and vehicle tracks. The general ecosystem characteristics chosen to provide integrative measures of the possible ecological effects include annual primary production and the relative aboveground growth of the different species or growth forms comprising the vegetation. Plant growth forms are defined by height, leaf longevity, position of the perennating bud, and rooting pattern. The growth forms and species selected are: erect deciduous shrubs (Betula nana, Vaccinium uliginosum, Salix pulchra); erect evergreen shrubs (Ledum palustre); prostrate evergreen shrub (Vaccinium vitis-idaea); tussock graminoid (Eriophorum vaginatum); rhizomatous graminoid (Carex bigelowii, Carex aquatilis, Eriophorum angustifolium); forb (Artemisia arctica); grass (Calamagrostis or Arctagrostis); cushion moss (Dicranum sp.); Sphagnum sp.; and Polytrichum commune. Progress is reported in field and laboratory studies. The main conclusion of the research is that species respond individually in terms of nutrient and total nonstructural carbohydrates accumulation to fertilization, and that the growth forms studied are not distinctive from each other on the basis of plant nutrition or growth. The explicit mechanism for integrating and guiding this research and for extrapolating the existing data base to make quantitative predictions of the effects of perturbations is a simulation model of arctic tundra vegetation and soil processes called ARTUS (Arctic Tundra Simulator). (JGB)

  7. Low molecular weight components of pollen alter bronchial epithelial barrier functions.

    Science.gov (United States)

    Blume, Cornelia; Swindle, Emily J; Gilles, Stefanie; Traidl-Hoffmann, Claudia; Davies, Donna E

    2015-01-01

    The bronchial epithelium plays a key role in providing a protective barrier against many environmental substances of anthropogenic or natural origin which enter the lungs during breathing. Appropriate responses to these agents are critical for regulation of tissue homeostasis, while inappropriate responses may contribute to disease pathogenesis. Here, we compared epithelial barrier responses to different pollen species, characterized the active pollen components and the signaling pathways leading to epithelial activation. Polarized bronchial cells were exposed to extracts of timothy grass (Phleum pratense), ragweed (Ambrosia artemisifolia), mugwort (Artemisia vulgaris), birch (Betula alba) and pine (Pinus sylvestris) pollens. All pollen species caused a decrease in ionic permeability as monitored trans-epithelial electrical resistance (TER) and induced polarized release of mediators analyzed by ELISA, with grass pollen showing the highest activity. Ultrafiltration showed that the responses were due to components isorhamnetin present in grass pollen contributed to the overall effect on airway epithelial barrier responses. In conclusion, bronchial epithelial barrier functions are differentially affected by several low molecular weight components released by pollen. Furthermore, ionic permeability and innate cytokine production are differentially regulated. PMID:26451347

  8. History of formation of forests in the plain part of Ukraine in the Holocene

    International Nuclear Information System (INIS)

    Full text: The authors analyzed and generalized the results of palynological and radiocarbon-dating studies of Holocene deposits of the forest, forest-steppe and steppe zones of Ukraine. Based on the obtained data, we reconstructed the pattern of main changes of vegetation and climate starting from 10,300 years BP. We consider changes in forest vegetation of the studied area in the Early (PB-1, PB-2, BO-1, BO-2, BO-3), Middle (AT-1, AT-2, AT-3, SB-1, SB-2, SB-3) and Late Holocene. For most important forest-forming trees (species of Pinus, Betula, Alnus, Quercus, Tilia, Carpinus, Fagus etc.), the main periods of their maximum participation in Ukrainian forest vegetation were identified. Broadleaf forests and mixed forests with participation of broadleaf trees were most widespread in Ukraine 4,500-6,200 years BP. During the second phase of the Atlantic time of the Holocene the northern border of the steppe zone in Ukraine was stable. Expansion of forest communities in the steppe zone progressed through gradual increase of forest areas that originally occurred in flood plains and ravines. (author)

  9. Forest biomass at Xiaolong Mountain in Gansu Province,China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In order to accurately estimate the size of the carbon pool and the capacity of the carbon sink in the forested areas of Xiaolong Mountain in Gansu Province,we have established regression equations of organ biomass of eight tree species.We measured and investigated the biomass of different forest stand types based on data from 1259 standard sample plots and 836 standard sample trees.for eight types of forest stands on Xiaolong Mountain,are as follows:Quercus aliena var.acuteserrata 84.05,Pinus tabulaeformis 62.44,Quercus variabilis 81.77,Populus sp.and Betula sp.combined 77.44,Larix sp.69.00,Pinus armandii 70.07,Picea sp.96.49 and Abies sp.98.72.We also looked at other broad-leaved mixed forests.Our study shows that the biomass of a single tree of each tree species is closely related to the diameter at breast height (DBH) and to tree height.The biomass of single trees as well as stand volumes is closely related to average DBH,average tree height and to stand density.

  10. Stomatal proxy record of CO2 concentrations during the Last Termination demonstrates dynamic climate behaviour and an important role for CO2.

    Science.gov (United States)

    Steinthorsdottir, Margret; Wohlfarth, Barbara; Kylander, Malin E.; Blaauw, Maarten; Reimer, Paula J.

    2013-04-01

    We present a new stomatal proxy-based record of CO2 concentrations spanning Greenland Interstadial 1 (Allerød pollen zone, GI-1a to 1c), Greenland Stadial 1 (Younger Dryas pollen zone, GS-1) and the first part of the Holocene (Preboreal pollen zone). The calibrated atmospheric CO2 concentrations are based on Betula nana (dwarf birch) leaves from a fossil lake sedimentary sequence in south-eastern Sweden. The stomatal proxy method relies on the inverse relationship between stomatal density on plant leaves and atmospheric CO2 concentrations to reconstruct variations in past CO2 concentrations. The record presented here demonstrates that the overall pattern of CO2 evolution during this period was dynamic, with significant abrupt fluctuations in CO2 concentration when the climate moved from interstadial to stadial state and vice versa. The cooling at the GI-1/GS-1 transition was preceded by an abrupt warming, and the warming at the GS-1/Holocene transition was preceded by an abrupt cooling. This scenario is in contrast to CO2 records reconstructed from air bubbles trapped in ice, which indicate a gradual increase in concentrations, but largely in alignment with previously published stomatal proxy-based CO2 records. A new loss-on-ignition chemical record (used here as a proxy for temperature), from the same locality, lends independent support to the CO2 record.

  11. A paleoecological reconstruction of the Late Glacial and Holocene based on multidisciplinary studies at Steregoiu site (Gutai Mts., Romania

    Directory of Open Access Journals (Sweden)

    Angelica Feurdean

    2001-09-01

    Full Text Available High resolution analyses of pollen, mineral magnetic properties, loss of ignition, lithostratigraphy and AMS 14C measurements of lake sediments and peat deposits accumulated in the former crater lake of Steregoiu (Gutâiului Mts., NW Romania, gave new and important information about vegetation and climate changes from the period GS-2 to the present. During the Lateglacial, three cold events were recorded: before 14,700 cal. years BP (GS-2, 14,050–13,800 cal. years BP (GI-1d, 12,900-11,500 cal. years BP (GS-1, and a warm climatic event between 13,800-12,950 cal. years BP (GI-1c to GL-1a. The Late Glacial/Holocene transition around 11,500 cal. years BP, was determined by an expansion of Betula, Alnus and Picea, followed by a rapid and strong expansion of Ulmus. At 10,700 cal. years BP, dense and highly diverse forests with Ulmus, Quercus, Tilia, Fraxinus and a few Acer and Corylus individuals dominated the area. Corylus and Picea were the dominant species in the forests from 10,150 to 8,500 cal. years BP. The first occurrence of single Fagus pollen grains was around 8,000 cal years BP. Only at 4,700 cal year BP Fagus and Carpinus became widespread and established trees in the local woodlands.

  12. Stomatal proxy record of CO2 concentrations from the last termination suggests an important role for CO2 at climate change transitions

    Science.gov (United States)

    Steinthorsdottir, Margret; Wohlfarth, Barbara; Kylander, Malin E.; Blaauw, Maarten; Reimer, Paula J.

    2013-05-01

    A new stomatal proxy-based record of CO2 concentrations ([CO2]), based on Betula nana (dwarf birch) leaves from the Hässeldala Port sedimentary sequence in south-eastern Sweden, is presented. The record is of high chronological resolution and spans most of Greenland Interstadial 1 (GI-1a to 1c, Allerød pollen zone), Greenland Stadial 1 (GS-1, Younger Dryas pollen zone) and the very beginning of the Holocene (Preboreal pollen zone). The record clearly demonstrates that i) [CO2] were significantly higher than usually reported for the Last Termination and ii) the overall pattern of CO2 evolution through the studied time period is fairly dynamic, with significant abrupt fluctuations in [CO2] when the climate moved from interstadial to stadial state and vice versa. A new loss-on-ignition chemical record (used here as a proxy for temperature) lends independent support to the Hässeldala Port [CO2] record. The large-amplitude fluctuations around the climate change transitions may indicate unstable climates and that “tipping-point” situations were involved in Last Termination climate evolution. The scenario presented here is in contrast to [CO2] records reconstructed from air bubbles trapped in ice, which indicate lower concentrations and a gradual, linear increase of [CO2] through time. The prevalent explanation for the main climate forcer during the Last Termination being ocean circulation patterns needs to re-examined, and a larger role for atmospheric [CO2] considered.

  13. Diet and nutrient balance of red panda in Nepal

    Science.gov (United States)

    Panthi, Saroj; Coogan, Sean C. P.; Aryal, Achyut; Raubenheimer, David

    2015-10-01

    We identified the winter plant species consumed by red panda in the Dhorpatan Hunting Reserve of eastern Nepal and compared this to the early-summer diet which was determined previously by Panthi et al. (2012). In addition, we estimated the proximate nutritional content of the leaves identified in red panda diet for both seasons, and we used nutritional geometry to explore macronutrient balance of leaves from the two different sampling periods. We identified six different plants in winter scats, which were the same as found in the previously determined early-summer diet. Arundinaria spp. bamboos were the main species found (82.1 % relative frequency), followed by Acer spp. (6.3 %), Betula utilis (4.6 %), Quercus semicarpifolia (3.7 %), Berberis spp. (1.3 %), and lichens (1.0 %), leaving 2.0 % unidentified. Geometric analysis suggested that the macronutrient balance of seasonal diets were similar in nutrient balance to the most frequently consumed Arundinaria spp. Differences in macronutrient balance may indicate seasonal nutrient preferences, such as increased carbohydrate intake in winter for thermogenesis, and increased protein and lipid intake in early summer to support reproduction and lactation; however, these differences may also indicate differences in resource availability. Habitat conserved for red panda in the region should include sufficient Arundinaria spp. as well as lesser consumed plants which may serve as complimentary foods.

  14. Suitability of thermoluminescence, chemiluminescence, ESR and viscosity measurements as detection method for the irradiation of medicinal herbs

    International Nuclear Information System (INIS)

    Chemiluminescence, electron spin resonance, thermoluminescence and viscosity measurements have been investigated for their suitability as detection method for the irradiation of the medicinal herbs anise seeds (anisi fructus), valerian roots (valerianae radix), redberry leaves (uvae ursi folium), birch leaves (betulae folium), greek hay seeds (foenugraeci semen), cayenne pepper (capsici fructus acer), black-aldertee bark (frangulae cortex), fennel fruits (feoniculi fructus), rose hip shells (cynosbati fructus), coltsfoot (farfarae folium), acorus roots (calami rhizoma), chamomile flowers (matricariae flos), caraway (carvi fructus), lavender flowers (lavandulae flos), linseed (lini semen), lime tree flowers (tiliae flos), St. Mary's thistle fruit (cardui mariae herba), lemon balm (melissae folium), java tea (orthosiphonis folium), peppermint (menthae piperitae folium), sage leaves (salviae folium), scouring rush (equiseti herba), senna leaves (sennae folium), plantain herbs (plantaginis lanceolata herba), thyme herbs (thymi herba), juniper berries (juniperi fructus), hawthorne herbs (crataegi folium), wheat starch (amylum tritici) and wormwood (absinthii herba). Depending on the herbs, the methods used were more or less suitable. Chemiluminescence measurements showed the smallest differences between untreated and irradiated samples whereas thermoluminescence measurements on isolated minerals from the vegetable drugs gave better results. In some herbs radiation-specific radicals could be identified by ESR spectroscopy. Viscosity measurement is suitable for some herbs as fast and inexpensive method for screening. (orig.)

  15. 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.

  16. A new electrodynamic balance design for low temperature studies

    Directory of Open Access Journals (Sweden)

    H.-J. Tong

    2014-07-01

    Full Text Available In this paper we describe a newly designed cold electrodynamic balance (CEDB system, which was built to study the evaporation kinetics and freezing properties of supercooled water droplets. The temperature of the CEDB chamber at the location of the levitated water droplet can be controlled in the range: −40 to +40 °C, which is achieved using a combination of liquid nitrogen cooling and heating by positive temperature coefficient heaters. The measurement of liquid droplet radius is obtained by analyzing the Mie elastic light scattering from a 532 nm laser. The Mie scattering signal was also used to characterize and distinguish droplet freezing events; liquid droplets produce a regular fringe pattern whilst the pattern from frozen particles is irregular. The evaporation rate of singly levitated water droplets was calculated from time resolved measurements of the radii of evaporating droplets and a clear trend of the evaporation rate on temperature was measured. The statistical freezing probabilities of aqueous pollen extracts (pollen washing water are obtained in the temperature range: −4.5 to −40 °C. It was found that that pollen washing water from water birch (Betula fontinalis occidentalis pollen can act as ice nuclei in the immersion freezing mode at temperatures as warm as −22.45 (±0.65 °C.

  17. 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.

  18. Airborne pollen spectrum and hay fever type prevalence in Vinnitsa, central Ukraine

    Directory of Open Access Journals (Sweden)

    Victoria Valeriivna Rodinkova

    2015-12-01

    Full Text Available The article deals with the main pollen spectrum in relation to patients’ sensitivity determined in the ambient air of Vinnitsa city located in central Ukraine. The study performed by gravimetric sampling in the years 1999–2000 and by volumetric sampling in the years 2009–2014 showed that Urtica, Betula, Pinus, Alnus, Fraxinus, Ambrosia, Artemisia, Juglans, Carpinus, Populus, Quercus, Acer, Salix, Poaceae, Amarathaceae, and Polygonaceae pollen grains are prevalent among the airborne allergen types in the urban atmosphere. The principal pollen types remain the same but over time their quantities have changed. The relative abundance of Carpinus and Amaranthaceae airborne pollen decreased while the fraction of Urtica pollen increased in the last decade. From 50 to 69 pollen types were determined in the ambient air depending on the season. From 24 to 27 pollen types represented woody plants and from 22 to 46 pollen types belonged to the herbaceous plants. A considerable decrease in herbal pollen types is noted in the Vinnitsa air at present. It was shown that children were sensitive to weed pollen grains, including ragweed, mugwort, and grass, while adults were more sensitive to tree and grass pollen grains. Further studies of the pollen spectrum in the ambient air of this city are required in order to control the hay fever symptoms.

  19. Depth distribution and composition of seed banks under different tree layers in a managed temperate forest ecosystem

    Science.gov (United States)

    Godefroid, Sandrine; Phartyal, Shyam S.; Koedam, Nico

    2006-05-01

    In the present work we examined the composition and distribution across three soil layers of the buried soil seed bank under three different overstory types ( Fagus sylvatica, Quercus robur, Pinus sylvestris) and in logging areas in a 4383-ha forest in central Belgium. The objectives were: (1) to investigate whether species composition and species richness of soil seed banks are affected by different forest stands; (2) to examine how abundant are habitat-specific forest species in seed banks under different planted tree layers. The study was carried out in stands which are replicated, managed in the same way (even-aged high forest), and growing on the same soil type with the same land-use history. In the investigated area, the seed bank did show significant differences under oak, beech, pine and in logging areas, respectively in terms of size, composition and depth occurrence. All species and layers taken together, the seed bank size ranked as follows: oakwood > beechwood > logging area > pinewood. The same pattern was found for forest species. Seed numbers of Betula pendula, Calluna vulgaris, Dryopteris dilatata and Rubus fruticosus were significantly higher under the beech canopy. Carex remota, Impatiens parviflora and Lotus sp. showed a significantly denser seed bank in logging areas, while Digitalis purpurea seeds were significantly more abundant in soils under the oak canopy. The fact that the seed bank of an originally homogeneous forest varies under different planted stands highlights that a long period of canopy conversion can affect the composition and depth of buried seeds.

  20. The effect of u.v.-B radiation on u.v.-absorbing secondary metabolites in birch seedlings grown under simulated forest soil conditions

    International Nuclear Information System (INIS)

    Birch (Betula pendula Roth) seedlings were grown under enhanced u.v.-B radiation and simulated forest-soil conditions, after which individual secondary metabolites were determined in the leaves. It was found that not all of the u.v.-absorbing secondary metabolites of the seedlings responded to supplementary u.v.-B radiation. Under increased u.v.-B radiation, significant increases in concentration were observed only for the major flavonoid, quercitrin, the minor fiavonoid, myricetin-3-galactoside, and for chlorogenic acid. On the other hand, 3,4′dihydroxypropiophenone-3-β-D-glucopyranoside decreased under u.v.-B irradiation. The concentration of phenolic compounds in the leaves changed during the growing season (between two harvests) but this change was not related to u.v.-B enhancement. A low availability of mineral nutrients did not impair the capacity of the seedlings to accumulate u.v.-protecting phenolic compounds under increased u.v.-B radiation. The growth conditions used might have affected the intracellular concentrations of secondary metabolites, and thus furnished the birch seedlings with an increased tolerance of u.v.-B radiation. These findings point to the significance of certain phenolic components in the protection of deciduous trees against u.v.-B radiation. (author)

  1. Reconstruction of vegetation and lake level at Moon Lake, North Dakota, from high-resolution pollen and diatom data

    Energy Technology Data Exchange (ETDEWEB)

    Grimm, E.C.; Laird, K.R.; Mueller, P.G. [Illinois State Museum, Springfield, IL (United States)]|[Univ. of Minnesota, Minneapolis, MN (United States)

    1995-06-01

    High-resolution fossil-pollen and diatom data from Moon Lake, North Dakota, reveal major climate and vegetation changes near the western margin of the tall-grass prairie. Fourteen AMS radiocarbon dates provide excellent time control for the past {approximately}11,800 {sup 14}C years B.P. Picea dominated during the late-glacial until it abruptly declined {approximately}10,300 B.P. During the early Holocene ({approximately}10,300-8000 B.P.), deciduous trees and shrubs (Populus, Betula, Corylus, Quercus, and especially Ulmus) were common, but prairie taxa (Poaceae, Artemisia, and Chenopodiaceae/Amaranthaceae) gradually increased. During this period the diatoms indicate the lake becoming gradually more saline as water-level fell. By {approximately}8000 B.P., salinity had increased to the point that the diatoms were no longer sensitive to further salinity increases. However, fluctuating pollen percentages of mud-flat weeds (Ambrosia and Iva) indicate frequently changing water levels during the mid-Holocene ({approximately}8000-5000 B.P.). The driest millennium was 7000-6000 B.P., when Iva annua was common. After {approximately}3000 B.P. the lake became less-saline, and the diatoms were again sensitive to changing salinity. The Medieval Warm Period and Little Ice Age are clearly evident in the diatom data.

  2. Catechol O-methyltransferase Val158Met polymorphism is associated with cognitive performance in nondemented adults.

    Science.gov (United States)

    de Frias, Cindy M; Annerbrink, Kristina; Westberg, Lars; Eriksson, Elias; Adolfsson, Rolf; Nilsson, Lars-Göran

    2005-07-01

    The catechol O-methyltransferase (COMT) gene is essential in the metabolic degradation of dopamine in the prefrontal cortex. In the present study, we examined the effect of a Val158Met polymorphism in the COMT gene on individual differences and changes in cognition (executive functions and visuospatial ability) in adulthood and old age. The participants were 292 nondemented men (initially aged 35-85 years) from a random sample of the population (i.e., the Betula study) tested at two occasions with a 5-year interval. Confirmatory factor analyses were used to test the underlying structure of three indicators of executive functions (verbal fluency, working memory, and Tower of Hanoi). Associations between COMT, age, executive functioning, and visuospatial (block design) tasks were examined using repeated-measures analyses of variance. Carriers of the Val allele (with higher enzyme activity) compared with carriers of the Met/Met genotype (with low enzyme activity) performed worse on executive functioning and visuospatial tasks. Individuals with the Val/Val genotype declined in executive functioning over the 5-year period, whereas carriers of the Met allele remained stable in performance. An Age x COMT interaction for visuospatial ability located the effect for middle-aged men only. This COMT polymorphism is a plausible candidate gene for executive functioning and fluid intelligence in nondemented middle-aged and older adults. PMID:16102234

  3. Fungal Assemblages in Different Habitats in an Erman’s Birch Forest

    Science.gov (United States)

    Yang, Teng; Sun, Huaibo; Shen, Congcong; Chu, Haiyan

    2016-01-01

    Recent meta-analyses of fungal diversity using deeply sequenced marker genes suggest that most fungal taxa are locally distributed. However, little is known about the extent of overlap and niche partitions in total fungal communities or functional guilds within distinct habitats on a local forest scale. Here, we compared fungal communities in endosphere (leaf interior), phyllosphere (leaf interior and associated surface area) and soil samples from an Erman’s birch forest in Changbai Mountain, China. Community structures were significantly differentiated in terms of habitat, with soil having the highest fungal richness and phylogenetic diversity. Endophytic and phyllosphere fungi of Betula ermanii were more phylogenetically clustered compared with the corresponding soil fungi, indicating the ability of that host plants to filter and select their fungal partners. Furthermore, the majority of soil fungal taxa were soil specialists, while the dominant endosphere and phyllosphere taxa were aboveground generalists, with soil and plant foliage only sharing forest were strictly niche specialized and constrained by weak migration among habitats. The findings suggest that phylogenetic relatedness and functional guilds’ assignment can effectively interpret the certain ecological processes. PMID:27625646

  4. Tc1-like transposable elements in plant genomes

    Science.gov (United States)

    2014-01-01

    Background The Tc1/mariner superfamily of transposable elements (TEs) is widespread in animal genomes. Mariner-like elements, which bear a DDD triad catalytic motif, have been identified in a wide range of flowering plant species. However, as the founding member of the superfamily, Tc1-like elements that bear a DD34E triad catalytic motif are only known to unikonts (animals, fungi, and Entamoeba). Results Here we report the identification of Tc1-like elements (TLEs) in plant genomes. These elements bear the four terminal nucleotides and the characteristic DD34E triad motif of Tc1 element. The two TLE families (PpTc1, PpTc2) identified in the moss (Physcomitrella patens) genome contain highly similar copies. Multiple copies of PpTc1 are actively transcribed and the transcripts encode intact full length transposase coding sequences. TLEs are also found in angiosperm genome sequence databases of rice (Oryza sativa), dwarf birch (Betula nana), cabbage (Brassica rapa), hemp (Cannabis sativa), barley (Hordium valgare), lettuce (Lactuta sativa), poplar (Populus trichocarpa), pear (Pyrus x bretschneideri), and wheat (Triticum urartu). Conclusions This study extends the occurrence of TLEs to the plant phylum. The elements in the moss genome have amplified recently and may still be capable of transposition. The TLEs are also present in angiosperm genomes, but apparently much less abundant than in moss. PMID:24926322

  5. Long-term ecological behaviour of abandoned uranium mill tailings. 1

    International Nuclear Information System (INIS)

    Inactive uranium mill tailings were surveyed in the Province of Ontario to describe their surface characteristics, identify naturally invading biota, and determine essential chemical and physical parameters associated with the tailings. Inactive tailings sites can have wet areas, tailings completely covered with water, and dry areas. In the wet areas of most sites, wetland vegetation stands were found which were dominated by species of cattails (Typhaceae), along with some species of rushes (Juncaceae) and sedges (Cyperceae). Dry areas of the tailings exhibited a variety of surface features which are often a reflection of different amelioration efforts. Most of the indigenous species of vascular plants identified on dry areas of the tailings occurred only sporadically. Invading plants found on most sites were the tree species, trembling aspen (Populus tremuloides) and paper birch (Betula papyrifera). Elemental concentration and some physical characteristics of the tailings collected from a depth of 0-20 cm were determined. Uptake of heavy metals and radionuclides were evaluated in trees found in the dry areas and in cattails (Typha latifolia) in the wetland areas. Water bodies on tailings and surface water leaving the tailings, before and after treatment, were characterized in this survey. Aquatic bryophytes have invaded some water bodies on the tailings, and acid tolerant algae were evident in most of the water associated with the tailings. Ecological processes occurring on inactive uranium mill tailings which were identified in this survey are essential in evaluating the long-term fate of these waste sites

  6. 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.

  7. Bioconversion of Birch Wood Hemicellulose Hydrolyzate to Xylitol.

    Science.gov (United States)

    Miura, Masahiro; Shimotori, Yasutaka; Nakatani, Hisayuki; Harada, Akira; Aoyama, Masakazu

    2015-06-01

    A sugar solution containing 42.9 g l(-1) of xylose was prepared from the wood of Japanese white birch (Betula platyphylla var. japonica) by hydrolysis with 3 % sulfuric acid with a liquor-to-solid ratio of 4 (g g(-1)) at 120 °C for 1 h. During the acid hydrolysis, undesirable by-products were generated, such as acetic acid, furfural, and low-molecular-weight phenols, which inhibit bioconversion of xylose to xylitol. These inhibitors were successfully removed from the hydrolyzate by sorption onto a steam-activated charcoal followed by treatment with an anion exchange resin. Bioconversion of the detoxified hydrolyzate to xylitol by the yeast Candida magnoliae was investigated under the microaerobic conditions. The oxygen transfer rate (OTR) varied from 9.6 to 22.3 mmol O2 l(-1) h(-1). The best fermentative performance of C. magnoliae in the birch wood hydrolyzate (xylitol yield 0.74 g xylitol g xylose(-1); volumetric productivity 1.0 g l(-1) h(-1)) was obtained at the OTR of 12.6 mmol O2 l(-1) h(-1). PMID:25894947

  8. Essential and non-essential elements in natural vegetation in southern Norway: Contribution from different sources

    Energy Technology Data Exchange (ETDEWEB)

    Nordløkken, Marit, E-mail: marit.nordlokken@ntnu.no; Berg, Torunn; Flaten, Trond Peder; Steinnes, Eiliv

    2015-01-01

    Concentrations of essential and non-essential elements in five widespread species of natural boreal vegetation were studied with respect to seasonal variation and contribution from different sources. The plant species included in the study were Betula pubescens, Sorbus aucuparia, Vaccinium myrtillus, Vaccinium uliginosum, Calluna vulgaris and Deschampsia flexuosa. Concentrations of elements essential to plants remained essentially constant or decreased slightly throughout the growing season. Concentrations of most non-essential elements increased or tended to increase on a dry mass basis from June to July as well as from July to September. The increasing trend for these elements was observed for all species except C. vulgaris. Principal component analysis (PCA) of the material indicated a common source for many of the non-essential elements; Sc, Ti, V, Ga, As, Y, Sb, lanthanides, Pb, Bi, and U, i.e. both elements presumably of geogenic origin and elements associated with trans-boundary air pollution. Uptake by plant roots appeared to be the main source of nutrient elements as well as some non-essential elements. - Highlights: • Concentrations of elements in different plant species were studied. • Changes in concentrations during a growing season were identified. • PCA indicated a common source for many of the non-essential elements. • Uptake by roots appeared to be the plant’s main source of nutrient elements.

  9. 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%.

  10. Pulse Pressure magnifies the effect of COMTVal158Met on 15 Year Episodic Memory Trajectories

    Directory of Open Access Journals (Sweden)

    Ninni ePersson

    2016-03-01

    Full Text Available We investigated whether a physiological marker of cardiovascular health, pulse pres­sure (PP, and age magnified the effect of the functional COMT Val158Met (rs4680 pol­ymor­phism on 15-year cognitive trajectories (episodic memory [EM], visuospatial ability, and se­man­tic memory using data from 1585 non-demented adults from the Betula study. A mul­tiple-group growth model was specified to gauge individual differences in change. The allelic variants showed negligible differences across the cognitive markers in average trends. The older portion of the sample selectively age-magnified the effects of Val158Met on EM changes, resulting in greater decline in Val compared to homozygote Met carriers. This effect was attenuated by sta­tistical control for PP. Further, PP mod­erated the effects of COMT on 15-year EM trajectories, resulting in greater decline in Val carriers, even after accounting for the confounding effects of sex, education, cardiovascular diseases (dia­betes, stroke, and hypertension, and chronological age, controlled for practice gains. The effect was still present after excluding individuals with a history of cardiovascular diseases. The effects of cognitive change were not moderated by any other covariates. This report underscores the importance of addressing synergistic effects in nor­mal cognitive aging, as the addition thereof may even place healthy individuals at greater risk for memory decline.

  11. The Contribution of Moss to Plot-Based Spectral Signals in Moist Acidic Low Arctic Tundra

    Science.gov (United States)

    May, J. L.; Beamish, A. L.

    2015-12-01

    To determine the contribution of moss to peak season normalized difference index (NDVI) field measurement of intact vegetation communities were compared to communities with individual species and litter successively removed until only the moss layer remained. Spectral measurements (n=3) were collected using a field radiometer in five upland and five lowland plots in a moist acidic tundra ecosystem at the Imnaviat Creek Watershed, North Slope Alaska. After spectral measurements were taken individual species were removed in the same order in each plot by clipping them at the moss layer. As individual species were removed NDVI values decreased. Decreases were greatest when dwarf shrub species Salix richardsonii sb. pulchra and Betula nana were removed. Notable increases in NDVI were observed once standing litter was removed. The NDVI values of the moss layer were comparable to intact vegetation communities depending on the bryophyte species composition. This suggests that the NDVI signal of moss is largely masked by vascular species but represents a significant factor missing from overall, large-scale NDVI signals. The results of this study corroborate recent data that points to the mismatch between ground based NDVI and aerial and satellite derived NDVI. This preliminary case study provides a strong basis for better characterization of the contribution of moss to NDVI for improved correction of air and space borne imagery.

  12. Molecular characterization of recombinant T1, a non-allergenic periwinkle (Catharanthus roseus) protein, with sequence similarity to the Bet v 1 plant allergen family.

    Science.gov (United States)

    Laffer, Sylvia; Hamdi, Said; Lupinek, Christian; Sperr, Wolfgang R; Valent, Peter; Verdino, Petra; Keller, Walter; Grote, Monika; Hoffmann-Sommergruber, Karin; Scheiner, Otto; Kraft, Dietrich; Rideau, Marc; Valenta, Rudolf

    2003-01-01

    More than 25% of the population suffer from Type I allergy, an IgE-mediated hypersensitivity disease. Allergens with homology to the major birch ( Betula verrucosa ) pollen allergen, Bet v 1, belong to the most potent elicitors of IgE-mediated allergies. T1, a cytokinin-inducible cytoplasmic periwinkle ( Catharanthus roseus ) protein, with significant sequence similarity to members of the Bet v 1 plant allergen family, was expressed in Escherichia coli. Recombinant T1 (rT1) did not react with IgE antibodies from allergic patients, and failed to induce basophil histamine release and immediate-type skin reactions in Bet v 1-allergic patients. Antibodies raised against purified rT1 could be used for in situ localization of natural T1 by immunogold electron microscopy, but did not cross-react with most of the Bet v 1-related allergens. CD analysis showed significant differences regarding secondary structure and thermal denaturation behaviour between rT1 and recombinant Bet v 1, suggesting that these structural differences are responsible for the different allergenicity of the proteins. T1 represents a non-allergenic member of the Bet v 1 family that may be used to study structural requirements of allergenicity and to engineer hypo-allergenic plants by replacing Bet v 1-related allergens for primary prevention of allergy. PMID:12656672

  13. Fossils and a large molecular phylogeny show that the evolution of species richness, generic diversity, and turnover rates are disconnected.

    Science.gov (United States)

    Xing, Yaowu; Onstein, Renske E; Carter, Richard J; Stadler, Tanja; Peter Linder, H

    2014-10-01

    The magnitude and extent of global change during the Cenozoic is remarkable, yet the impacts of these global changes on the biodiversity and evolutionary dynamics of species diversification remain poorly understood. To investigate this question, we combine paleontological and neontological data for the angiosperm order Fagales, an ecologically important clade of about 1370 species of trees with an exceptional fossil record. We show differences in patterns of accumulation of generic diversity, species richness, and turnover rates for Fagales. Generic diversity evolved rapidly since the Late Cretaceous and peaked during the Eocene or Oligocene. Turnover rates were high during periods of extreme global climate change, but relatively low when the climate remained stable. Species richness accumulated gradually throughout the Cenozoic, possibly at an accelerated pace after the Middle Miocene. Species diversification occurred in new environments: Quercoids radiating in Oligocene subtropical seasonally arid habitats, Casuarinaceae in Australian pyrophytic biomes, and Betula in Late Neogene holarctic habitats. These radiations were counterbalanced by regional extinctions in Late Neogene mesic warm-temperate forests. Thus, the overall diversification at species level is linked to regional radiations of clades with appropriate ecologies exploiting newly available habitats.

  14. Can Urban Trees Reduce the Impact of Climate Change on Storm Runoff?

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    Katarina ZABRET

    2015-11-01

    Full Text Available The process of urbanisation leads to significant changes in surface cover, which influence the hydrological properties of an area. The infiltration of precipitation into the soil is reduced, so that both surface water runoff and the velocity at which water travels have increased drastically. In recent decades climate change has also been observed to affect precipitation trends. Many studies have shown that the amount of rainfall is increasing and that heavy rainfall events are becoming more frequent. These changes are producing more runoff, which has to be drained. Urban trees can reduce the amount of precipitation reaching the ground due to rainfall interception, and are becoming increasingly recognized as an effective means for the regulation of storm water volumes and costs. The study measured rainfall interception in an urban area. It shows that Betula pendula can intercept 20.6% of annual rainfall, whereas Pinus nigra could intercept as much as 51.0% of annual rainfall. The advantage of rainfall interception was shown in the case of a parking lot where the planting of trees was able to reduce runoff by up to 17%.

  15. Elevated Atmospheric CO2 Affects Ectomycorrhizal Species Abundance and Increases Sporocarp Production under Field Conditions

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    Douglas L. Godbold

    2015-04-01

    Full Text Available Anthropogenic activities during the last century have increased levels of atmospheric CO2. Forest net primary productivity increases in response to elevated CO2, altering the quantity and quality of carbon supplied to the rhizosphere. Ectomycorrhizal fungi form obligate symbiotic associations with the fine roots of trees that mediate improved scavenging for nutrients in exchange for a carbohydrate supply. Understanding how the community structure of ectomycorrhizal fungi is altered by climate change is important to further our understanding of ecosystem function. Betula pendula and Fagus sylvatica were grown in an elevated CO2 atmosphere delivered using free air carbon dioxide enrichment (FACE under field conditions in the U.K., and Picea abies was grown under elevated CO2 in glass domes in the Czech Republic. We used morphotyping and sequencing of the internal transcribed spacer region of the fungal ribosomal operon to study ectomycorrhizal community structure. Under FACE, un-colonised roots tips increased in abundance for Fagus sylvatica, and during 2006, sporocarp biomass of Peziza badia significantly increased. In domes, ectomycorrhizal community composition shifted from short-distance and smooth medium-distance to contact exploration types. Supply and competition for carbon belowground can influence ectomycorrhizal community structure with the potential to alter ecosystem function.

  16. Putative forest glacial refugia in the Western and Eastern Carpathians

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    Józef Mitka

    2014-04-01

    Full Text Available An examination of thermophilous species pollen deposits found in the Plenivistulian river alluvial terraces in the Polish Western Carpathians was conducted. Of the 16 palaeobotanical sites evaluated, most often noted were Alnus and Betula t. alba; Abies, Carpinus and Corylus occurred less frequently, and Quercus, Tilia and Ulmus were rare. Fagus and Fraxinus pollen were absent. Abies and Carpinus were relatively overrepresented, because their frequency of occurrence was similar to Corylus avellana, i.e. one of the most cold-resistant species. Based on a literature survey of phylogeographic studies and data regarding the forest species Aconitum moldavicum, A. variegatum, Bromus benekenii, Carpinus betulus, Lathyrus vernus, Lonicera nigra, and the moderately thermophilous Rosa pendulina, 47 cryptic refugial areas of temperate plant species are postulated. The combined analysis indicates that they could have survived the last glaciation in the W & E Carpathian microrefugia close to 650 m a.s.l., and in Podolia (north of the Eastern Carpathians along a contour of 300 m a.s.l.

  17. Co-occurrence of airborne allergenic pollen grains and fungal spores in Rzeszów, Poland (2000-2002

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    Idalia Kasprzyk

    2012-12-01

    Full Text Available The co-occurrence of airborne allergenic pollen grains and fungal spores was estimated in Rzeszów in the years 2000-2002. The volumetric method was used in this aerobiological study. Six taxa of pollen grains and five types of fungal spores characterized by strong allergenicity and/or high concentrations in the air were analyzed. The time series of pollen grains and fungal spores were compared using PCA analysis. The periods of the greatest concentrations of tree pollen did not coincide with similar periods for herbaceous plants and fungal spores. From February to mid-March, Alnus pollen dominated in the air. The second period was characterized by Betula pollen. It occurred in April. Herbaceous pollen and fungal spores occurred in the air simultaneously (from mid May to the end of August, creating a risky situation for sensitized people. The periods of the highest concentrations of Epicoccum and Ganoderma fungal spores did not coincide with the same period for the examined plant taxa. In Rzeszów the probability of becoming exposed to very high concentrations of allergenic pollen and fungal spores at the same time was high, especially in July, when the highest concentrations of Poaceae, Alternaria and Cladosporium were noted. The hypersensitivity to only one plant or fungal allergen is rarely encountered. Under the present scenarios of global warming, pollen seasons of many taxa will be longer and sufferers will have year-long symptoms.

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

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    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.

  19. Coupled long-term summer warming and deeper snow alters species composition and stimulates gross primary productivity in tussock tundra.

    Science.gov (United States)

    Leffler, A Joshua; Klein, Eric S; Oberbauer, Steven F; Welker, Jeffrey M

    2016-05-01

    Climate change is expected to increase summer temperature and winter precipitation throughout the Arctic. The long-term implications of these changes for plant species composition, plant function, and ecosystem processes are difficult to predict. We report on the influence of enhanced snow depth and warmer summer temperature following 20 years of an ITEX experimental manipulation at Toolik Lake, Alaska. Winter snow depth was increased using snow fences and warming was accomplished during summer using passive open-top chambers. One of the most important consequences of these experimental treatments was an increase in active layer depth and rate of thaw, which has led to deeper drainage and lower soil moisture content. Vegetation concomitantly shifted from a relatively wet system with high cover of the sedge Eriophorum vaginatum to a drier system, dominated by deciduous shrubs including Betula nana and Salix pulchra. At the individual plant level, we observed higher leaf nitrogen concentration associated with warmer temperatures and increased snow in S. pulchra and B. nana, but high leaf nitrogen concentration did not lead to higher rates of net photosynthesis. At the ecosystem level, we observed higher GPP and NEE in response to summer warming. Our results suggest that deeper snow has a cascading set of biophysical consequences that include a deeper active layer that leads to altered species composition, greater leaf nitrogen concentration, and higher ecosystem-level carbon uptake. PMID:26747269

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

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    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.

  1. Characteristic of Tuber spp. localities in natural stands with emphasis on plant species composition

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    Dorota Hilszczanska

    2014-12-01

    Full Text Available Fungi belonging to the genus Tuber establish ectomycorrhizal symbioses with shrubs, trees and some herbaceous plants. Some Tuber species, for example, T. melanosporum, T. magnatum, T. aestivum are economically important because they produce edible fruiting bodies with a distinctive taste and flavor. Our concept of truffle ecophysiology is dominated by the symbiosis with deciduous hosts, such as: Quercus spp., Fagus sylvatica, Castanea sativa, Corylus spp., Carpinus betulus, Ostrya carpinifolia, Betula verrucosa, and Tilia spp., whereas the real range of hosts in nature seems to be much wider. Moreover, interactions between Tuber mycelium and plant community could be more complex than just forming the ectomycorrhizal symbiosis. Here we show our inventory of plants and soils at six truffle’ sites in the southern part of Poland (Nida Basin and Przedbórz Upland. The aim of this study was to widen our understanding of ecological factors affecting Tuber spp., in the context of pioneering stage of research on truffles in Poland. We hope our findings will have a practical application and will help to choose suitable soils for truffle orchards.

  2. Annual and Monthly Variations in Litter Macronutrients of Three Subalpine Forests in Western China

    Institute of Scientific and Technical Information of China (English)

    YANG Wan-Qin; WANG Kai-Yun; S.KELLOM(A)KI; ZHANG Jian

    2006-01-01

    Macronutrients (N, P, K, Ca, Mg, and S) in litter of three primarily spruce (Picea purpurea Masters) (SF), fir (Abies faxoniana Rehder & E. H. Wilson) (FF), and birch (Betula platyphylla Sukaczev) (BF) subalpine forests in western China were measured to understand the monthly variations in litter nutrient concentrations and annual and monthly nutrient returns via litterfall. Nutrient concentration in litter showed the rank order of Ca > N > Mg > K > S > P. Monthly variations in nutrient concentrations were greater in leaf litter (LL) than other litter components. The highest and lowest concentrations of N, P, K, and S in LL were found in the growing season and the nongrowing season, respectively, but Ca and Mg were the opposite. Nutrient returns via litterfall showed a marked monthly pattern with a major peak in October and one or two small peaks in February and/or May, varying with the element and stand type, but no marked monthly variations in nutrient returns via woody litter, reproductive litter, except in May for the BF, and moss litter. Not only litter production but also nutrient concentration controlled the annual nutrient return and the monthly nutrient return pattern. The monthly patterns of the nutrient concentration and return were of ecological importance for nutrient cycling and plant growth in the subalpine forest ecosystems.

  3. The role of selected tree species in industrial sewage sludge/flotation tailing management.

    Science.gov (United States)

    Mleczek, Mirosław; Rutkowski, Paweł; Niedzielski, Przemysław; Goliński, Piotr; Gąsecka, Monika; Kozubik, Tomisław; Dąbrowski, Jędrzej; Budzyńska, Sylwia; Pakuła, Jarosław

    2016-11-01

    The aim of the study was to estimate the ability of ten tree and bush species to tolerate and accumulate Cd, Cu, Pb, Zn, and As species [As(III), As(V), and total organic arsenic] in industrial sewage sludge extremely contaminated with arsenic (almost 27.5 g kg(-1)) in a pot experiment. The premise being that it will then be possible to select the most promising tree/bush species, able to grow in the vicinity of dams where sewage sludge/flotation tailings are used as landfill. Six of the ten tested tree species were able to grow on the sludge. The highest content of total As was observed in Betula pendula roots (30.0 ± 1.3 mg kg(-1) DW), where the dominant As species was the toxic As(V). The highest biomass of Quercus Q1 robur (77.3 § 2.6 g) and Acer platanoides (76.0 § 4.9 g) was observed. A proper planting of selected tree species that are able to thrive on sewage sludge/flotation tailings could be an interesting and promising way to protect dams. By utilizing differences in their root systems and water needs, we will be able to reduce the risk of fatal environmental disasters. PMID:27348264

  4. Long-Term Arctic Peatland Dynamics, Vegetation and Climate History of the Pur-Taz Region, Western Siberia

    Science.gov (United States)

    Peteet, Dorothy; Andreev, Andrei; Bardeen, William; Mistretta, Francesca

    1998-01-01

    Stratigraphic analyses of peat composition, LOI, pollen, spores, macrofossils, charcoal, and AMS ages are used to reconstruct the peatland, vegetation and climatic dynamics in the Pur-Taz region of western Siberia over 5000 years (9300 - 4500 BP). Section stratigraphy shows many changes from shallow lake sediment to different combinations of forested or open sedge, moss, and Equisetum fen and peatland environments. Macrofossil and pollen data indicate that Larix sibirica and Betula pubescens trees were first to arrive, followed by Picea obovata. The dominance of Picea macrofossils 6000-5000 BP in the Pur-Taz peatland along with regional Picea pollen maxima indicate warmer conditions and movement of the spruce treeline northward at this time. The decline of pollen and macrofossils from all of these tree species in uppermost peats suggests a change in the environment less favorable for their growth, perhaps cooler temperatures and/or less moisture. Of major significance is the evidence for old ages of the uppermost peats in this area of Siberia, suggesting a real lack of peat accumulation in recent millennia or recent oxidation of uppermost peat.

  5. Regeneration dynamics of dominant tree species along an altitudinal gradient in moist temperate valley slopes of the Garhwal Himalaya

    Institute of Scientific and Technical Information of China (English)

    Sumeet Gairola; C.M.Sharma; S.K.Ghildiyal; Sarvesh Suyal

    2012-01-01

    The present study was undertaken in moist temperate forest of Mandal-Chopta area in the Garhwal region of Uttarakhand,India.The aim of the present study was to understand the regeneration dynamics of the dominant tree species along an altitudinal gradient in naturally regenerating,restricted access forest.The overall regeneration status was fairly high in the study area.Most of the native canopy and undercanopy dominants had frequent reproduction and expanding populations,which suggests the stability of forest structure/composition and further expansion of dominant species.The overall regeneration of trees in the forest had a greater contribution of middle and understorey species.Because of infrequent reproduction and declining populations of some of the dominant native species viz.,Abies pindrow,Alnus nepalensis and Betula alnoides,structural/compositional changes in the future are expected in respective forests dominated by them.Abies pindrow and Taxus baccata need immediate attention by forest managers for their survival in the area.Seedlings were found to be more prone to competition from herb and shrubs than saplings.

  6. Predicting leaf wax n-alkane 2H/1H ratios: controlled water source and humidity experiments with hydroponically grown trees confirm predictions of Craig-Gordon model.

    Science.gov (United States)

    Tipple, Brett J; Berke, Melissa A; Hambach, Bastian; Roden, John S; Ehleringer, James R

    2015-06-01

    The extent to which both water source and atmospheric humidity affect δ(2)H values of terrestrial plant leaf waxes will affect the interpretations of δ(2)H variation of leaf waxes as a proxy for hydrological conditions. To elucidate the effects of these parameters, we conducted a long-term experiment in which we grew two tree species, Populus fremontii and Betula occidentalis, hydroponically under combinations of six isotopically distinct waters and two different atmospheric humidities. We observed that leaf n-alkane δ(2)H values of both species were linearly related to source water δ(2)H values, but with slope differences associated with differing humidities. When a modified version of the Craig-Gordon model incorporating plant factors was used to predict the δ(2)H values of leaf water, all modelled leaf water values fit the same linear relationship with n-alkane δ(2)H values. These observations suggested a relatively constant biosynthetic fractionation factor between leaf water and n-alkanes. However, our calculations indicated a small difference in the biosynthetic fractionation factor between the two species, consistent with small differences calculated for species in other studies. At present, it remains unclear if these apparent interspecies differences in biosynthetic fractionation reflect species-specific biochemistry or a common biosynthetic fractionation factor with insufficient model parameterization.

  7. The rhizosphere and PAH amendment mediate impacts on functional and structural bacterial diversity in sandy peat soil

    International Nuclear Information System (INIS)

    To reveal the degradation capacity of bacteria in PAH polluted soil and rhizosphere we combined bacterial extradiol ring-cleavage dioxygenase and 16S rRNA analysis in Betula pubescens rhizoremediation. Characterisation of the functional bacterial community by RFLP revealed novel environmental dioxygenases, and their putative hosts were studied by 16S rRNA amplification. Plant rhizosphere and PAH amendment effects were detected by the RFLP/T-RFLP analysis. Functional species richness increased in the birch rhizosphere and PAH amendment impacted the compositional diversity of the dioxygenases and the structural 16S rRNA community. A shift from an Acidobacteria and Verrucomicrobia dominated to an Alpha- and Betaproteobacteria dominated community structure was detected in polluted soil. Clone sequence analysis indicated catabolic significance of Burkholderia in PAH polluted soil. These results advance our understanding of rhizoremediation and unveil the extent of uncharacterized functional bacteria to benefit bioremediation by facilitating the development of the molecular tool box to monitor bacterial populations in biodegradation. - The bacterial community analysis using 16S rRNA and extradiol dioxygenase marker genes in rhizoremediation revealed both a rhizosphere and a PAH-pollution effect.

  8. Encroachment of woody species on a drained transitional peat bog in ‘Mszar Bogdaniec’ nature reserve (Western Poland

    Directory of Open Access Journals (Sweden)

    Dyderski Marcin K.

    2015-09-01

    Full Text Available One of the most important threats for open peat bog ecosystems is encroachment of woody species, which causes transformation of habitat conditions and leads to retreat of specialised species. Drainage increases the rate of succession. The aim of study is the assessment of human-accelerated succession in a transitional bog. The study was conducted in ‘Mszar Bogdaniec’ nature reserve (W Poland. The structure of vegetation and tree stands was described and compared using ordination methods. Near the peat bog border, tree stands of Betula pubescens developed. Towards the middle part of the peat bog, the number, cover and height of trees decreased. The central part of the peat bog was covered by Sphagno recurvi–Eriophoretum vaginati in dryer parts and Sphagno recurvi–Eriophoretum angustifolii in wetter parts. The study showed that the successional sequence in these conditions differs from the classical bog succession scheme. Despite high propagule pressure of Pinus sylvestris, the most important woody species was B. pubescens, which performed better than other species. Erechtites hieracifolia, an alien invasive herb species, which previously was rarely recorded in bogs, appeared when the bog was dried by drainage. In this study, it reached high frequency and abundance, which shows that it may be a next serious threat to disturbed wetland ecosystems.

  9. A large herbivore triggers alternative successional trajectories in the boreal forest.

    Science.gov (United States)

    Hidding, Bert; Tremblay, Jean-Pierre; Côté, Steeve D

    2013-12-01

    Alternative successional trajectories (AST) may result in multiple climax states within an ecosystem when disturbances affect colonization history. In the boreal forest, ungulates have been proposed to drive AST because, under herbivore pressure, preferred species may go extinct and apparent competition may benefit browsing-resistant species. Over a 15-year period following logging, we tested whether deer herbivory altered plant species composition and whether the competitive advantage of resistant species was maintained following herbivore removal. We compared exclosures built immediately after logging with delayed exclosures built eight years later on Anticosti Island, Quebec, Canada. Although the palatable tree Betula papyrifera (paper birch) and some palatable herbs recovered in delayed exclosures, we observed legacies in both tree and herb cover. Woody regeneration in delayed exclosures was dominated by Picea glauca (white spruce), and Poaceae (grasses) were abundant in the field layer. Given that only early-successional species recovered, whereas late-successional broadleaf species and Abies balsamea (balsam fir) remained rare, succession may follow an AST after a limited browsing period during early succession. PMID:24597230

  10. The likely impact of climate change on the biodiversity of Italian forests

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    Borghetti M

    2012-12-01

    Full Text Available Based on literature results and our expert evaluation, we report some likely impacts of climate change on the biodiversity of forest communities in Italy by the end of this century. In the Mediterranean region and on the Apennines: at low altitudes, vulnerability of Pinus sp. and Quercus ilex forests, with loss of intraspecific genetic variability; transition from Mediterranean closed-canopy macchia to scattered shrublands; risk of local extinction for coastal populations of mesic/relic hardwood species (e.g., Quercus robur, Carpinus betulus, Zelkova sicula, Fraxinus sp.; ’eastern’ relic species like Quercus troiana, Quercus frainetto, Quercus aegilops, and Q. gussonei in Sicily, and the peripheral low-altitude Fagus sylvatica populations, will be highly vulnerable; in the mid-altitude forest, vulnerability of most demanding species like Quercus cerris and Castanea sativa, possible immigration of Mediterranean species like Quercus ilex; in the montane forest, Fagus sylvatica and Abies alba will be less competitive with respect to more continental and drought-resistant tree species, and could loose genetic variability; relic species like Taxus baccata and Betula aetnensis may be at risk. In the alpine region: upward movement of timberline and changes in timberline communities, for instance Picea abies may be more competitive over Larix decidua, and fragmented species like Pinus cembra might become vulnerable. In general, we recognize the difficulty in separating the effects of climatic variables from those of other processes, like fires and land-use change.

  11. Study on the Relationship between Forest Fire and Forest Types in Saihanba Forest Center%塞罕坝机械林场森林类型与林火关系的研究

    Institute of Scientific and Technical Information of China (English)

    于士涛

    2014-01-01

    该文通过对塞罕坝机械林场野外调查获取实地数据来分析林场的林型特征与火灾的关系,得出结论如下:樟子松纯林属于极易燃类型;白桦林属于中等易燃类型;蒙古栎林属较易燃类型;落叶松和白桦的混交林内属于较难燃类型;落叶松、樟子松和云杉的混交林内属于较易燃类型。%In this dissertation datum gotten by some field investigation was also used to analyze the rela⁃tion between forest fire and the character of forest. The main conclusions as follows:Forest of L. gmelinii is difficult to burn;forest of Pinus sylvestris var. mongolica Litv is very inflammable;forest of Betula platy⁃phylla Suk is mid-inflammable;forest of Quercus mongolica Fisch is correspondingly inflammable. Mixed for⁃est of L. gmelinii and P. sylvestris var. mongolica Litv is uninflammable;mixed forest of L. gmelinii,P. syl⁃vestris var. mongolica Litv and Picea asperata Mast is correspondingly inflammable.

  12. Variance analysis on different trees species depending on soil type – uncontaminated and heavy metals contaminated ones

    Directory of Open Access Journals (Sweden)

    Monica MARIAN

    2008-05-01

    Full Text Available This paper summarizes our research work regarding the dynamics of vegetation growth of miscellaneous species of trees planted and monitored in the particular environment of the tailing pond in Bozanta Mare (Maramures County. The structure of soil bearing high content of heavy metals and cyanides considerably impacts the ecologic conditions of tailing ponds. Aspects related to soil characteristics (such as structure, size of particles, porosity, texture, chemical composition are included. Vegetal species that have accommodated within the tail pond are included as well. In the framework of our experiment we have planted seedlings belonging to four species of trees: Quercus petraea, Populus tremula, Betula verrucosa, Salix caprea. We have planted the seedlings in different location contexts in the tailing pond (“in situ”, as we have also planted “ex situ” witness trees. Our aim was to monitor the dynamics of growth of the stem and of cuttings. Our contribution, based on the outcomes of our research, consists in the formulation of functional correlations spotted between cormophites and micro biota, between the species of trees and their environmental underlying conditions, with the overarching goal to optimize the activities undertaken in order to alleviate the tailing ponds inherent to mining activities.

  13. Arctic Shrub Growth Response to Climate Variation and Infrastructure Development on the North Slope of Alaska

    Science.gov (United States)

    Ackerman, D.; Finlay, J. C.; Griffin, D.

    2015-12-01

    Woody shrub growth in the arctic tundra is increasing on a circumpolar scale. Shrub expansion alters land-atmosphere carbon fluxes, nutrient cycling, and habitat structure. Despite these ecosystem effects, the drivers of shrub expansion have not been precisely established at the landscape scale. This project examined two proposed anthropogenic drivers: global climate change and local infrastructure development, a press disturbance that generates high levels of dust deposition. Effects of global change were studied using dendrochronology to establish a relationship between climate and annual growth in Betula and Salix shrubs growing in the Alaskan low Arctic. To understand the spatial heterogeneity of shrub expansion, this analysis was replicated in shrub populations across levels of landscape properties including soil moisture and substrate age. Effects of dust deposition on normalized difference vegetation index (NDVI) and photosynthetic rate were measured on transects up to 625 meters from the Dalton Highway. Dust deposition rates decreased exponentially with distance from road, matching previous models of road dust deposition. NDVI tracked deposition rates closely, but photosynthetic rates were not strongly affected by deposition. These results suggest that dust deposition may locally bias remote sensing measurements such as NDVI, without altering internal physiological processes such as photosynthesis in arctic shrubs. Distinguishing between the effects of landscape properties, climate, and disturbance will improve our predictions of the biogeochemical feedbacks of arctic shrub expansion, with potential application in climate change modeling.

  14. β-Amyloid binding in elderly subjects with declining or stable episodic memory function measured with PET and [{sup 11}C]AZD2184

    Energy Technology Data Exchange (ETDEWEB)

    Mattsson, Patrik [Karolinska Institutet, Centre for Psychiatry Research, Department of Clinical Neuroscience, Stockholm (Sweden); Karolinska University Hospital, Karolinska Institutet, Department of Clinical Neuroscience, Centre for Psychiatry Research, Stockholm (Sweden); Forsberg, Anton; Halldin, Christer [Karolinska Institutet, Centre for Psychiatry Research, Department of Clinical Neuroscience, Stockholm (Sweden); Persson, Jonas; Nilsson, Lars-Goeran [Karolinska Institute and Stockholm University, Aging Research Center (ARC), Stockholm (Sweden); Nyberg, Lars [Umeaa University, Department of Radiation Sciences (Diagnostic Radiology), Umeaa (Sweden); Farde, Lars [Karolinska Institutet, Centre for Psychiatry Research, Department of Clinical Neuroscience, Stockholm (Sweden); AstraZeneca Translational Science Center at Karolinska Institutet, Stockholm (Sweden)

    2015-09-15

    Cognitive decline has been suggested as an early marker for later onset of Alzheimer's disease. We therefore explored the relationship between decline in episodic memory and β-amyloid using positron emission tomography (PET) and [{sup 11}C]AZD2184, a radioligand with potential to detect low levels of amyloid deposits. Healthy elderly subjects with declining (n = 10) or stable (n = 10) episodic memory over 15 years were recruited from the population-based Betula study and examined with PET. Brain radioactivity was measured after intravenous administration of [{sup 11}C]AZD2184. The binding potential BP{sub ND} was calculated using linear graphical analysis with the cerebellum as reference region. The binding of [{sup 11}C]AZD2184 in total grey matter was generally low in the declining group, whereas some binding could be observed in the stable group. Mean BP{sub ND} was significantly higher in the stable group compared to the declining group (p = 0.019). An observation was that the three subjects with the highest BP{sub ND} were ApoE ε4 allele carriers. We conclude that cognitive decline in the general population does not seem to stand by itself as an early predictor for amyloid deposits. (orig.)

  15. Pseudometallophytes colonising Pb/Zn mine tailings: a description of the plant-microorganism-rhizosphere soil system and isolation of metal-tolerant bacteria.

    Science.gov (United States)

    Becerra-Castro, C; Monterroso, C; Prieto-Fernández, A; Rodríguez-Lamas, L; Loureiro-Viñas, M; Acea, M J; Kidd, P S

    2012-05-30

    The plant-microorganism-soil system of three pseudometallophytes (Betula celtiberica, Cytisus scoparius and Festuca rubra) growing in a Pb/Zn mine was characterised. Plant metal accumulation, soil metal fractions (rhizosphere and non-vegetated) and bacterial densities were determined. Total Cd, Pb and Zn in non-vegetated soils was up to 50, 3000 and 20,000 mg kg(-1) dry weight, respectively. The residual fraction dominated non-vegetated soils, whereas plant-available fractions became important in rhizosphere soils. All plant species effectively excluded metals from the shoot. F. rubra presented a shoot:root transport factor of ≤0.2 and this population could be useful in future phytostabilisation trials. Culturable bacterial densities and diversity were low (predominantly Actinobacteria). Rhizosphere soils hosted higher total and metal-tolerant bacterial densities. Seventy-four metal-tolerant rhizobacteria were isolated, and characterised genotypically (BOX-PCR, 16S rDNA) and phenotypically [Cd/Zn tolerance, biosurfactant production and plant growth promoting (PGP) traits]. Several isolates resisted high concentrations of Cd and Zn, and only a few presented PGP traits. Fourteen isolates were evaluated for promoting plant growth of two species (Salix viminalis and Festuca pratensis). Thirteen inoculants enhanced growth of F. pratensis, while only three enhanced growth of S. viminalis. Growth enhancement could not always be related to isolate PGP traits. In conclusion, some isolates show potential application in phytostabilisation or phytoextraction techniques. PMID:22483595

  16. Surface pollen and its relationship to vegetation in the Zoige Basin, eastern Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    Furong LI; Yan ZHAO; Jinghui SUN; Wenwei ZHAO; Xiaoli GUO; Ke ZHANG

    2011-01-01

    We use a data set of 23 surface pollen samples from moss polsters in the Zoige Basin to explore the relationship between modem pollen assemblages and contemporary vegetation patterns.The surface pollen samples spanned four types of plant communities:Carex muliensis marsh,Stipa and Kobresia meadow,Carexdominated forb meadow and Sibiraea angustata scrub.Principal-components analysis(PCA)was used to determine the relationships between modem pollen and vegetation and environmental variables.The results show that the pollen assemblages of surface moss samples generally reflect the features of the modem vegetation,basically similar in the vegetation types and the dominant genera; however,they don't show a very clear distinction between different communities.Our results also demonstrate that pollen representation of different families or genus varied.Some tree taxa,such as Pinus and Betula,and herb types,such as Artemisia are over-represented,while Asteraceae,Ranunculaceae and Cyperaceae are moderately represented,and Poaceae and Rosaceae are usually under-represented in our study region.PCA results indicate that the distribution of vegetation in the Zoige Basin is mainly controlled by precipitation and altitude.

  17. Environmental monitoring program for the Ormen Lange Onshore Processing Plant and the Reserve Power Plant at Nyhamna, Gossa. Monitoring of vegetation and soil: re-analyses and establishment of new monitoring plots in 2010.; Miljoeovervaakingsprogram for Ormen Lange landanlegg og Reservegasskraftverk paa Nyhamna, Gossa. Overvaaking av vegetasjon og jord: gjenanalyser og nyetablering av overvaakingsfelter i 2010

    Energy Technology Data Exchange (ETDEWEB)

    Aarrestad, P.A.; Bakkestuen, V.; Stabbetorp, O.E.; Myklebost, Heidi

    2011-07-01

    conducted for three distinct habitats: wet oligotrophic heathland, and hummocks and lawns on raised bogs. The site in hummocks was established in 2010, whereas the other sites were re-analyzed with the same methods as in 2008. The parameters are monitored within delimited plots. The vegetation is monitored in permanently marked plots (0.5m x 0.5m), ten for each vegetation type at each site, in total 60 plots. In each plot the abundance of vascular plants, bryophytes and lichens are recorded, as well as the cover of the vegetation layers. Plant growth is measured in each site for 20 individuals of Betula nana, Calluna vulgaris, and Sphagnum capillifolium. Five samples of each of Racomitrium lanuginosum, Sphagnum capillifolium and Cladonia arbuscula from each site are collected and analyzed for plant nutrient content and the heavy metals copper (Cu), nickel (Ni), mercury (Hg), lead (Pb), and zinc (Zn). Ten soil samples are collected from each habitat at each site and analyzed for ph, Kjeldahl nitrogen, exchangeable elements, cation exchange capacity, and base saturation, a total of 30 samples from each site. The heavy metals Cu, Ni, Hg, Pb, and Zn are measured in samples of peat mud, 10 samples from each site. Peat water is analyzed for chemical nutrients and heavy metals, 10 samples from each site. The chemical analyses are conducted at the Norwegian Forest and Landscape Institute and NILU. There is still no indication that any pollution has affected the species composition of the vegetation. The vegetation is stable at both sites, both in wet heathland and in lawns on raised bogs. A few species occurring at low frequency in 2008 were not recorded in 2010, and some previously unrecorded species were found. This is normal for re-analyses of vegetation. There were significant differences in plant growth for Betula nana and Calluna vulgaris between the two sites, with highest growth rate at Aukra. This is most likely due to better climatic. (Author)

  18. Species diversity of epiphytic bryophytes in Baihua Mountain National Nature Reserve,Beijing%北京百花山自然保护区树附生苔藓植物物种多样性

    Institute of Scientific and Technical Information of China (English)

    田晔林; 李俊清; 石爱平; 于建军; 王文和

    2013-01-01

    An investigation was conducted on the species diversity of epiphytic bryophytes in Baihua Mountain National Nature Reserve, Beijing in 2004-2010. A total of 495 specimens were recorded, belonging to 34 species, 21 genera, and 13 families, among which, Pottiaceae, Leskeaceae, Entodontaceae, Orthotrichaceae, and Hypnaceae were the dominant families, and Lindbergia sinensis, Pylaisiella polyantha, L. brachyptera, and Frullania musicicola were the dominant species. There were three peaks of the vertical distribution of the epiphytic bryophytes, i. e. , altitude 1700 m (10 species) , and only 5 species were distributed at altitude 1200-1300 m. Shannon index was the highest for Betula platyphylla ( 1. 816) and the smallest for Juglans mandshurica (1. 500) , Pielou evenness index was the highest for Populus davidiaria (0. 910) and the smallest for Q. liaotungensis (0.591) , Simpson index was the highest for Q. liaotungensis (0.335) and the smallest for P. davidiana (0. 181) , and Patrick index was the highest for Q. liaotungensis (13) and the smallest for P. davidiana and J. mandshurica (7). The species diversity indices of the epiphytic bryophytes were related to habitat, bark crack, and water availability.%北京百花山保护区树附生苔藓植物共有13科21属34种,其中优势科有丛藓科(Pottiaceae)、薄罗藓科(Leskeaceae)、绢藓科(Entodontaceae)、木灵藓科(Orthotrichaceae)和灰藓科(Hypnaceae),优势种有中华细枝藓(Lindbergia sinensis)、金灰藓(Pylaisiella polyantha)、细枝藓(L.brachyptera)、盔瓣耳叶苔(Frullania musicicola)等.海拔1200 m以下地带(14种)、海拔1400 ~ 1500 m地带(11种)以及海拔1700 m以上地带(10种)是百花山树附生苔藓植物垂直分布的3个高峰.海拔1200 ~ 1300 m为低谷(5种).树附生植物物种Shannon指数最大的是白桦(Betula platyphylla)(1.816),最小的是核桃楸(Juglans mandshurica)(1.500);山杨(Populus davidiana)树附生植物的Pielou均匀度指数最高(0

  19. Community structure and regeneration characteristics of Taxus yunnanensis in northwest Yunnan Province of Southwest China%滇西北云南红豆杉群落结构与更新特征

    Institute of Scientific and Technical Information of China (English)

    刘万德; 李帅锋; 张志钧; 苏建荣

    2012-01-01

    Taking the Taxus yunnanensis communities in northwest Yunnan Province as test ob-jects and based on the field investigation data at three sites ( Lanping, Xianggelila, and Ninglang counties) of northwest Yunnan, this paper analyzed the species composition, species diversity, stem size class, and regeneration features of the T. yunnanensis communities. The dominant spe-cies in the T. yunnanensis communities were Yushania niitakayamensis, Tsuga dumosa, T. yun-nanensis , Betula albo-sinensis, and Fargesia yunnanensis. Xianggelila had the higher species richness of family, genus, and shrubs than the other two counties, but no significant differences were observed in the species richness of trees and lianas and the total species richness among the three counties. Lanping and Xianggelila had the higher species richness and abundance at smal-ler size classes (DBH < 5 cm) , while Ninglang had the highest species richness and abundance at the second diameter class (1 cm≤DBH < 5 cm) and height class (5 cm≤H<10 m). The wild T. yunnanensis population had weak regeneration ability through seedling, but had stronger sprouting ability. The ratio of the stems through sprouting to through seedling was 1. 314. The major sprouting types at all of the three sites were stem basal sprouting and stem epicormic sprou-ting. Ninglang had the highest sprouting stems, but all the three sites had no significant differ-ences in the mean diameter and height of sprouting stems.%以云南西北部云南红豆杉(Taxus yunnanensis)群落为研究对象,利用在兰坪县、香格里拉县和宁蒗县的野外样地调查数据,分析了云南红豆杉群落物种组成、多样性、结构及云南红豆杉更新特征.结果表明:云南红豆杉群落主要物种包括玉山竹(Yushania niitakayamensis)、云南铁杉(Tsuga dumosa)、云南红豆杉、红桦(Betula albo-sinensis)和云南箭竹(Fargesia yunnanensis).香格里拉县具有较高的科、属、灌木物种丰富度,但乔木、

  20. Comprehensive Evaluation of Forest Community Stability of Different Types of Low-Quality Forest Stands in the Greater Higgnan Mountains%大兴安岭不同类型低质林群落稳定性的综合评价

    Institute of Scientific and Technical Information of China (English)

    宋启亮; 董希斌

    2014-01-01

    The low-quality forest community stability was comprehensively evaluated by calculating subordinate function values of a model which was established based on fuzzy synthetic evaluation by a total of 30 factors of 5 indices of species diversity,soil physical properties,soil chemical properties,litter characteristics and soil carbon flux in 5 typical low-quality forest stands that mixed conifer and broadleaved forest,Populus davidiana forest,Quercus mongolica forest,Betula platyphylla forest and broadleaved mixed forest in the Greater Higgnan Mountains. The results showed that: The indices of species diversity,litter characteristics and soil carbon flux of mixed conifer and broadleaved forest are highest,the index of soil chemical properties of broadleaved mixed forest is highest,the index of soil physical properties of Quercus mongolica forest is highest,forest community stability of 5 types of forest communities in the Great Higgnan Mountains,ranked in the decreasing order of community of mixed conifer and broadleaved forest > broadleaved mixed forest > Quercus mongolica forest>Betula platyphylla forest >Populus davidiana forest. The evaluation results can provide theoretical basis for the ecosystem restoration of low-quality forest stands in the Greater Higgnan Mountains.%以大兴安岭林区分布的针阔混交林、山杨林、蒙古栎林、白桦林和阔叶混交林5种典型低质林森林群落类型为研究对象,选择反映森林群落基本特征的物种多样性、土壤物理性质、土壤化学性质、枯落物特性和土壤碳通量这5项指标,共30个评价因子,运用模糊数学中隶属函数的方法综合评价低质林森林群落稳定性。结果表明:针阔混交林物种多样性、枯落物特性、土壤碳通量指标最高,阔叶混交林土壤化学性质指标最高,蒙古栎林土壤物理性质指标最高,大兴安岭5种森林群落稳定性表现为针阔混交林>阔叶混交林>蒙古栎林>白

  1. 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

  2. 我国东北4种常见阔叶乔木物候对气候变化的响应%Response of 4 Common Broad-Leaved Arbors Phenology to Climate Change in the Northeast China

    Institute of Scientific and Technical Information of China (English)

    裴顺祥; 郭泉水; 辛学兵; 刘玮; 洪明

    2011-01-01

    物候现象是指示气候及自然环境变化的重要指标(Pe(n)uelas et al.,2001;Moresette et al.,2009).自然物候记录可以提供全球环境变化最直接和最有效的证据.已有研究结果表明,受全球气候变化影响,1952-2000年地中海地区(Pe(n)uelas et al.,2001)、1851-1994年匈牙利(Walkovszky,1998)、1936-1998年美国Wisconsin地区(Bradley et al.,1999)和1970-1999年美国华盛顿地区(Abu-Asab et al.,2001)的许多植物花期提前了1个星期左右;中国北纬33°左右地区植物的早春物候每10年提前1.1 ~4.3天,晚春物候提前1.4~5.4天(Zheng et al.,2006).%In order to reveal the response of four broad - leaved arbors to climate change, we studied relationships between interannual variations of air temperature and various phenophases (I.e., seasonal biological events) of broad-leaved arbors species ( Betula platyphylla, Juglans mandshurica, Ulmus pumila and Morus alba ) in the Harbin, based on meteorological data from 1951 -2008 and phenological data from 1963 -2008. Results showed that the air temperature in Harbin had an increasing trend from 1951 to 2008, especially after 1978. The increase of the annual minimum temperature was greater than that of the annual maximum temperature and annual mean temperature. Annual precipitation slightly increased, but not significantly. In the period of 1963 -2008, bud burst, beginning of leaf expansion and first flowering of the 4 species all shifted to 5. 7 d, 10. 2 d and 7. 9 d earlier, respectively, and end of leaf - falling was delayed for 7. 5 d. The pattern of phenological change was consistent with that of air temperature change. The phenophases earlier or later was mainly subjected to air temperature, especially the mean temperature of the same month and previous month when phenophase began. The phenophase had little correlation with the precipitation. When the mean temperature in March rose up by 1 ℃ , Betula platyphylla, Juglans mandshurica, Ulmus pumila

  3. Holocene local forest history at two sites in Småland, southern Sweden - insights from quantitative reconstructions using the Landscape Reconstruction Algorithm

    Science.gov (United States)

    Cui, Qiaoyu; Gaillard, Marie-José; Lemdahl, Geoffrey; Olsson, Fredrik; Sugita, Shinya

    2010-05-01

    et al.; Trondman et al., CL 1.22; Mazier et al. CL 1.21) we used 3 sets of pollen taxa (20, 22, 31) and 3 sets of pollen productivity estimates (PPEs) (1. southern Sweden; 2. southern Sweden except for cereals, Calluna, Plantago and Rumex, Denmark; 3. the mean of all PPEs available in NW Europe). The Spearman rank correlation test shows that there are no significant differences between the 9 runs. LOVE was applied on the pollen records from the two small bogs following the same strategy. We also compared the LOVE estimates (20 taxa, PPEs dataset 2) with the records of plant macro-remains and coleoptera species that are indicators of the local occurrence of conifers (Pinus and Picea), Betula, and deciduous trees. The results show large discrepancies between the LOVE estimates and pollen percentages. The LOVE estimates are higher than pollen percentages for Cyperaceae, Gramineae and Filipendula, and the broaded-leaved trees Corylus, Fraxinus, and Tilia. In contrast, the LOVE estimates for Pinus and Betula are generally much lower than their pollen percentages. LOVE estimates and pollen percentages are relatively similar for Alnus, Quercus, and Calluna. The LOVE reconstruction confirms the assumed difference between the sites in terms of the abundance of birch and pine, which was not clearly demonstrated by the pollen percentages and accumulation rates. The Pinus LOVE estimates are significantly higher at one of the sites, which explains the differences in fire history between the sites. The comparison of the LOVE estimates with plant macro-remains and coleoptera species shows a good correspondence. References: Greisman, A. and Gaillard, MJ, 2009. Journal of Quaternary Science, 24(6):593-611. Olsson, F. et al. 2009. Palaeogeography, Palaeoclimatology, Palaeoecology, 10.1016/j.palaeo.2009.07.013 Sugita, S., 1993. Quaternary Research, 39:239-244. Sugita, S., 2007a. The Holocene, 17(2):229-241. Sugita, S., 2007b. The Holocene, 17(2):243-257.

  4. Altitudinal gradients of soil and vegetation carbon and nitrogen in a high altitude nature reserve of Karakoram ranges.

    Science.gov (United States)

    Shedayi, Arshad Ali; Xu, Ming; Naseer, Iqnaa; Khan, Babar

    2016-01-01

    This study aimed to investigate the correlation of carbon and nitrogen in soil and leaves with the altitude, vegetation type, herbaceous biomass (HB), litter mass (LM) and with each other. Soil and leaf samples collected from different forest types along altitudinal gradients in the Karakoram Mountains. Dry and gas law methods were used for the chemical analysis. Regression models used for correlation analysis and T test for comparison. The correlation of soil total carbon (STC) and soil total nitrogen (STN) along altitudinal gradients and correlation between soil organic carbon (SOC) and STN was significantly positive with the values R(2) = 0.1684, p = 0.01, R(2) = 0.1537, p = 0.009 and R(2) = 0.856, p = 7.31E-10 respectively, while it was non-significant between soil inorganic carbon (SIC) and altitude and also between SIC and STN. The concentration of SOC and STN was highest in the broad leaved Betula utilis forest (22.31, 1.6 %) and least in the mixed (Pinus, Juniper, Betula) forest soil (0.85, 0.09 %) respectively. In the tree species leaf total carbon (LTC) and leaf total nitrogen (LTN) were highest in the Pinus wallichiana (PW) (632.54, 19.77), and least in the Populus alba (87.59, 4.06). In the shrub species LTC and LTN nitrogen were highest in the Rosa webiana (235.64, 7.45) and least in the Astragalus gilgitensis (43.45, 1.60) respectively. Total carbon and total nitrogen showed a slightly decreasing and increasing trend with altitude in the leaf and soil samples, respectively. The mean nitrogen and carbon was higher in the leaves of trees (3, 97.95) than in the shrubs (2.725, 74.24) and conifers (2.26, 76.46) than in the leaves of the deciduous (2, 46.36) trees. The correlation between LTC and STN was non-significant. Strong significant (R(2) = 0.608, p = 0.003) and weak non-significant (R(2) = 0.04, p = 0.32) relationships were found in STN and STC with LM and HB respectively. SOC (75.15 %) was found to be the main contributor to

  5. 冀北山地天然次生林土壤有机质空间异质性研究%Spatial Variability of Soil Organic Matte in Natural Secondary Forest

    Institute of Scientific and Technical Information of China (English)

    梁文俊; 魏曦; 朱宝才

    2015-01-01

    【目的】以冀北山地山杨白桦天然次生林为研究对象,探讨该群落土壤垂直方向有机质的分布格局和空间变异特征。【方法】采用大面积野外调查数据,运用统计学、GIS 空间结构分析技术进行分析。结果表明:土壤有机质含量最高的是0~20 cm 层,20~40 cm 有机质含量最小。变异系数随土壤深度的增加逐渐增大,3层都属于中度变异;3层有机质含量的最佳理论模型分别为指数模型、高斯模型和球型模型;各层有机质含量集中区和插值分析分级面积有所不同,但总体变化规律是一致的。0~20 cm 土层土壤有机质含量最大,20~40 cm 层是有机质消耗集中区,有机质含量最小,40~60 cm 层处于中等水平。【结论】研究区是属于次生山杨白桦林,土壤环境受外界破坏较少,土层垂直方向空间变异不显著,母质层有机质的形成和表层土壤有机质的消耗都处在合理的范围内,体现了该区域土壤处于健康、可持续发展的良好状态。%Objective]Populus davidiana + Betula platyphylla natural secondary forest was used as research objective in this study.The aim of this study was to explore the vertical distribu-tion and spatial variation of soil organic matter of the forest.[Method]Field survey data,statis-tics and GIS spatial structure analysis techniques were used in this study.[Results]The content of soil organic matter was the highest in the 0-20 cm layer but the content of 20-40cm was the lowest.The coefficient of variation increased with increasing soil depth and three layers belonged to moderate variation.The best theoretical models of organic matter in three layer were exponen-tial,Gaussian and spherical models.Each layer organic matter content focus area and interpola-tion analysis grade area was different,but the overall change was the same.Soil organic matter of 0 -20 cm layer was the largest.Soil layer of 20-40 cm was

  6. Natural Regeneration Pattern of Urban Forests in Harbin%哈尔滨城市森林自然演替格局研究

    Institute of Scientific and Technical Information of China (English)

    梅琳琳; 冯树丹; 达良俊; 宋坤; 王冰; 关兵兵

    2012-01-01

    In order to strengthen the urban protects of the variety of vegetation biodiversity and reasonable utilization, to perfect the system of ecology theory about the urban vegetation, the author did a lot of research about Haerbin urban forest natural succession pattern. The author decided to adopt the vegetation sociology research combine with every wood investigation research, researching 11 kinds of urban forest natural regeneration pattern in Harbin. The results showed that the difference kinds and quantities of composition about the woody plants under the forest different types of urban forest in maintaining woody plant diversity were quite different. Based on frequency distribution of DBH, population structure of each tree species fell into 3 types: unimodal type, L type and sporadic type. In the case, 4 representative species belonged to unimodal type: Populus berolinensis, Pinus tabulaeformis var. mukdensis, Larix gmelini, Pinus sylvestris var. mongolic; 4 L-types were: Populus davidiana, Phellodendron amurense, Fraxinus mandshurica, and Ulmus pumila; 3 sporadic types were: Juglans mandshurica, Betula platyphylla, and Picea koraiensis. It was suggested that the habitat, the seed resources and the seed dispersal pattern were the key limitation of urban forests.%为了加强城市植被生物多样性的保护与合理利用,完善城市植被生态学研究的理论体系,对哈尔滨城市森林自然演替格局进行研究.采用植被社会学调查与每木调查相结合的方法,对哈尔滨11种城市森林类型进行天然更新格局研究.结果表明,林下木本植物的种类和数量组成有所差异,不同城市森林类型在维持木本植物多样性方面存在较大差异.根据胸径级频率分布的形状,将各树种的种群结构归纳为3种类型:种群结构单峰型的为中东杨(Populus berolinensis)、黑皮油松(Pinus tabulaeformis var.mukdensis)、兴安落叶松(Larix gmelini)、樟子松(Pinus sylvestris var

  7. 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

  8. Altitudinal variation of soil organic carbon stocks in temperate forests of Kashmir Himalayas, India.

    Science.gov (United States)

    Ahmad Dar, Javid; Somaiah, Sundarapandian

    2015-02-01

    Soil organic carbon stocks were measured at three depths (0-10, 10-20, and 20-30 cm) in seven altitudes dominated by different forest types viz. Populus deltoides, 1550-1800 m; Juglans regia, 1800-2000 m; Cedrus deodara, 2050-2300 m; Pinus wallichiana, 2000-2300 m; mixed type, 2200-2400 m; Abies pindrow, 2300-2800 m; and Betula utilis, 2800-3200 m in temperate mountains of Kashmir Himalayas. The mean range of soil organic carbon (SOC) stocks varied from 39.07 to 91.39 Mg C ha(-1) in J. regia and B. utilis forests at 0-30 cm depth, respectively. Among the forest types, the lowest mean range of SOC at three depths (0-10, 10-20, and 20-30 cm) was observed in J. regia (18.55, 11.31, and 8.91 Mg C ha(-1), respectively) forest type, and the highest was observed in B. utilis (54.10, 21.68, and 15.60 Mg C ha(-1), respectively) forest type. SOC stocks showed significantly (R (2) = 0.67, P = 0.001) an increasing trend with increase in altitude. On average, the percentages of SOC at 0-10-, 10-20-, and 20-30-cm depths were 53.2, 26.5, and 20.3 %, respectively. Bulk density increased significantly with increase in soil depth and decreased with increase in altitude. Our results suggest that SOC stocks in temperate forests of Kashmir Himalaya vary greatly with forest type and altitude. The present study reveals that SOC stocks increased with increase in altitude at high mountainous regions. Climate change in these high mountainous regions will alter the carbon sequestration potential, which would affect the global carbon cycle.

  9. Patterns of plant diversity in seven temperate forest types of Western Himalaya, India

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    Javid Ahmad Dar

    2016-09-01

    Full Text Available Plant biodiversity patterns were analyzed in seven temperate forest types [Populus deltoides (PD, Juglans regia, Cedrus deodara, Pinus wallichiana, mixed coniferous, Abies pindrow (AP and Betula utilis (BU] of Kashmir Himalaya. A total of 177 plant species (158 genera, 66 families were recorded. Most of the species are herbs (82.5%, while shrubs account for 9.6% and trees represent 7.9%. Species richness ranged from 24 (PD to 96 (AP. Shannon, Simpson, and Fisher α indices varied: 0.17–1.06, 0.46–1.22, and 2.01–2.82 for trees; 0.36–0.94, 0.43–0.75, and 0.08–0.35 for shrubs; and 0.35–1.41, 0.27–0.95, and 5.61–39.98 for herbs, respectively. A total of five species were endemic. The total stems and basal area of trees were 35,794 stems (stand mean 330 stems/ha and 481.1 m2 (stand mean 40.2 m2/ha, respectively. The mean density and basal area ranged from 103 stems/ha (BU to 1,201 stems/ha (PD, and from 19.4 m2/ha (BU to 51.9 m2/ha (AP, respectively. Tree density decreased with increase in diameter class. A positive relationship was obtained between elevation and species richness and between elevation and evenness (R2 = 0.37 and 0.19, respectively. Tree and shrub communities were homogenous in nature across the seven forest types, while herbs showed heterogeneous distribution pattern.

  10. Paleontology, paleoclimatology and paleoecology of the late middle miocene Musselshell Creek flora, Clearwater County Idaho. A preliminary study of a new fossil flora

    Energy Technology Data Exchange (ETDEWEB)

    Baghai, N.L. [Univ. of Texas, Austin, TX (United States); Jorstad, R.B. [Eastern Illinois Univ., Charleston, IL (United States)

    1995-10-01

    The Musselshell Creek flora (12.0-10.5 Ma) of northern Idaho is used to reconstruct paleoclimatic and paleoecologic parameters of the Pacific Northwest during the late Middle Miocene. Other megafossil and microfossil floral records spanning 12.0-6.4 Ma are unknown from this region. The Musselshell Creek fossil flora, previously undescribed, is preserved in lacustrine clays and sediments that accumulated in a narrow valley surrounded by rugged terrain. Dominant taxa include dicotyledons and conifers. Most of the leaves are preserved as impressions or compressions. Some fossil leaves retained their original pigmentation, cellular anatomy, and organic constituents. Other fossils include excellent remains of pollen and spores, dispersed leaf cuticle, pyritized wood, and disarticulated fish bones. A destructive statistical analysis of one block of sediment, approximately 30 cm x 45 cm (1.5 sq. ft) recovered 14 orders, 23 families, and 34 genera of spermatophyte plant fossils. These floral elements are compared with two other earlier Miocene floras which were similarly sampled. Common megafossil genera include Quercus, Zizy-phoides, Taxodium, Alnus, Castanea, Magnolia, Acer, Ex-bucklandia, Sequoia, Populus, and Betula. The rare occurrence of Ginkgo leaves is a first record of this taxon in the Idaho Miocene. Additional plant taxa, are represented by palynomorphs. Common pollen taxa are Pinus, Abies, Carya, Quercus, and Tilia. Most of the megafossil and microfossil flora assemblage is characteristic of a streambank to floodplain environment that existed in a warm to cool temperate climate similar to the modern Mid-Atlantic coast of the United States. 47 refs., 5 figs., 4 tabs.

  11. 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.

  12. Chemometrics in biomonitoring: Distribution and correlation of trace elements in tree leaves.

    Science.gov (United States)

    Deljanin, Isidora; Antanasijević, Davor; Bjelajac, Anđelika; Urošević, Mira Aničić; Nikolić, Miroslav; Perić-Grujić, Aleksandra; Ristić, Mirjana

    2016-03-01

    The concentrations of 15 elements were measured in the leaf samples of Aesculus hippocastanum, Tilia spp., Betula pendula and Acer platanoides collected in May and September of 2014 from four different locations in Belgrade, Serbia. The objective was to assess the chemical characterization of leaf surface and in-wax fractions, as well as the leaf tissue element content, by analyzing untreated, washed with water and washed with chloroform leaf samples, respectively. The combined approach of self-organizing networks (SON) and Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) aided by Geometrical Analysis for Interactive Aid (GAIA) was used in the interpretation of multiple element loads on/in the tree leaves. The morphological characteristics of the leaf surfaces and the elemental composition of particulate matter (PM) deposited on tree leaves were studied by using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) detector. The results showed that the amounts of retained and accumulated element concentrations depend on several parameters, such as chemical properties of the element and morphological properties of the leaves. Among the studied species, Tilia spp. was found to be the most effective in the accumulation of elements in leaf tissue (70% of the total element concentration), while A. hippocastanum had the lowest accumulation (54%). After water and chloroform washing, the highest percentages of removal were observed for Al, V, Cr, Cu, Zn, As, Cd and Sb (>40%). The PROMETHEE/SON ranking/classifying results were in accordance with the results obtained from the GAIA clustering techniques. The combination of the techniques enabled extraction of additional information from datasets. Therefore, the use of both the ranking and clustering methods could be a useful tool to be applied in biomonitoring studies of trace elements. PMID:26748000

  13. Transpiration of urban trees and its cooling effect in a high latitude city

    Science.gov (United States)

    Konarska, Janina; Uddling, Johan; Holmer, Björn; Lutz, Martina; Lindberg, Fredrik; Pleijel, Håkan; Thorsson, Sofia

    2016-01-01

    An important ecosystem service provided by urban trees is the cooling effect caused by their transpiration. The aim of this study was to quantify the magnitude of daytime and night-time transpiration of common urban tree species in a high latitude city (Gothenburg, Sweden), to analyse the influence of weather conditions and surface permeability on the tree transpiration, and to find out whether tree transpiration contributed to daytime or nocturnal cooling. Stomatal conductance and leaf transpiration at day and night were measured on mature street and park trees of seven common tree species in Gothenburg: Tilia europaea, Quercus robur, Betula pendula, Acer platanoides, Aesculus hippocastanum, Fagus sylvatica and Prunus serrulata. Transpiration increased with vapour pressure deficit and photosynthetically active radiation. Midday rates of sunlit leaves ranged from less than 1 mmol m-2 s-1 ( B. pendula) to over 3 mmol m-2 s-1 ( Q. robur). Daytime stomatal conductance was positively related to the fraction of permeable surfaces within the vertically projected crown area. A simple estimate of available rainwater, comprising of precipitation sum and fractional surface permeability within the crown area, was found to explain 68 % of variation in midday stomatal conductance. Night-time transpiration was observed in all studied species and amounted to 7 and 20 % of midday transpiration of sunlit and shaded leaves, respectively. With an estimated night-time latent heat flux of 24 W m-2, tree transpiration significantly increased the cooling rate around and shortly after sunset, but not later in the night. Despite a strong midday latent heat flux of 206 W m-2, a cooling effect of tree transpiration was not observed during the day.

  14. Do elevations in temperature, CO2, and nutrient availability modify belowground carbon gain and root morphology in artificially defoliated silver birch seedlings?

    Science.gov (United States)

    Huttunen, Liisa; Saravesi, Karita; Markkola, Annamari; Niemelä, Pekka

    2013-09-01

    Climate warming increases the risk of insect defoliation in boreal forests. Losses in photosynthetically active surfaces cause reduction in net primary productivity and often compromise carbon reserves of trees. The concurrent effects of climate change and removal of foliage on root growth responses and carbohydrate dynamics are poorly understood, especially in tree seedlings. We investigated if exposures to different combinations of elevated temperature, CO2, and nutrient availability modify belowground carbon gain and root morphology in artificially defoliated 1-year-old silver birches (Betula pendula). We quantified nonstructural carbohydrates (insoluble starch as a storage compound; soluble sucrose, fructose, and glucose) singly and in combination in fine roots of plants under winter dormancy. Also the total mass, fine root proportion, water content, and length of roots were defined. We hypothesized that the measured properties are lower in defoliated birch seedlings that grow with ample resources than with scarce resources. On average, fertilization markedly decreased both the proportion and the carbohydrate concentrations of fine roots in all seedlings, whereas the effect of fertilization on root water content and dry mass was the opposite. However, defoliation mitigated the effect of fertilization on the root water content, as well as on the proportion of fine roots and their carbohydrate concentrations by reversing the outcomes. Elevation in temperature decreased and elevation in CO2 increased the absolute contents of total nonstructural carbohydrates, whereas fertilization alleviated both these effects. Also the root length and mass increased by CO2 elevation. This confirms that surplus carbon in birch tissues is used as a substrate for storage compounds and for cell wall synthesis. To conclude, our results indicate that some, but not all elements of climate change alter belowground carbon gain and root morphology in defoliated silver birch seedlings.

  15. Boron nutrition affects the carbon metabolism of silver birch seedlings.

    Science.gov (United States)

    Ruuhola, Teija; Keinänen, Markku; Keski-Saari, Sarita; Lehto, Tarja

    2011-11-01

    Boron (B) is an essential micronutrient whose deficiency is common both in agriculture and in silviculture. Boron deficiency impairs the growth of plants and affects many metabolic processes like carbohydrate metabolism. Boron deficiency and also excess B may decrease the sink demand by decreasing the growth and sugar transport which may lead to the accumulation of carbohydrates and down-regulation of photosynthesis. In this study, we investigated the effects of B nutrition on the soluble and storage carbohydrate concentrations of summer leaves and autumn buds in a deciduous tree species, Betula pendula Roth. In addition, we investigated the changes in the pools of condensed tannins between summer and autumn harvests. One-year-old birch seedlings were fertilized with a complete nutrient solution containing three different levels of B: 0, 30 and 100% of the standard level for complete nutrient solution. Half of the seedlings were harvested after summer period and another half when leaves abscised. The highest B fertilization level (B100) caused an accumulation of starch and a decrease in the concentrations of hexoses (glucose and fructose) in summer leaves, whereas in the B0 seedlings, hexoses (mainly glucose) accumulated and starch decreased. These changes in carbohydrate concentrations might be related to the changes in the sink demand since the autumn growth was the smallest for the B100 seedlings and largest for the B30 seedlings that did not accumulate carbohydrates. The autumn buds of B30 seedlings contained the lowest levels of glucose, glycerol, raffinose and total polyols, which was probably due to the dilution effect of the deposition of other substances like phenols. Condensed tannins accumulated in high amounts in the birch stems during the hardening of seedlings and the largest accumulation was detected in the B30 treatment. Our results suggest that B nutrition of birch seedlings affects the carbohydrate and phenol metabolism and may play an important

  16. Retranslocation of foliar nutrients of deciduous tree seedlings in different soil condition under free-air O3 enrichment

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    Shi C

    2016-06-01

    Full Text Available Retranslocation is the amount of an element that is depleted from old plant components and is provided for new growth. Leaf senescence is usually accelerated at elevated O3 (eO3, and leaf shedding is influenced by soil nutrient availability (and acidification. In this study, we focused on the net retranslocation and allocation dynamics of foliar nutrients (N, P, Mg, K, Ca, Mn, Fe and Al to investigate the effect of eO3 on birch (Betula platyphylla var. japonica, oak (Quercus mongolica var. crispula, and beech (Fagus crenata seedlings grown in different soil conditions. Seedlings of the 3 species were planted in a free-air O3 enrichment system under 3 soil types (brown forest soil, serpentine soil, volcanic ash soil for one growing season. All tree species were grown with 3 replications per each plot at elevated O3 (about 80 ppb and ambient condition (O3 ranging 25-35 ppb. Leaf samples were taken from the top part of seedlings during the growing season in mid-September, and senescing leaves were sampled in mid-November. Both were collected for chemical composition analysis. Retranslocation rate of P was markedly increased by eO3 in birch and significantly differed among soil types in oak seedlings, while was constant across treatments in beech seedlings. Retranslocation of N in oak seedlings was significantly affected by soil type. Retranslocation of other elements was most sensitive to both eO3 and soil type in beech seedlings. The influence of differential growth patterns among species in modulating the physiological response of seedlings to high levels of ozone and different soil conditions are discussed.

  17. How reproducible are the measurements of leaf fluctuating asymmetry?

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    Mikhail V. Kozlov

    2015-06-01

    Full Text Available Fluctuating asymmetry (FA represents small, non-directional deviations from perfect symmetry in morphological characters. FA is generally assumed to increase in response to stress; therefore, FA is frequently used in ecological studies as an index of environmental or genetic stress experienced by an organism. The values of FA are usually small, and therefore the reliable detection of FA requires precise measurements. The reproducibility of fluctuating asymmetry (FA was explored by comparing the results of measurements of scanned images of 100 leaves of downy birch (Betula pubescens conducted by 31 volunteer scientists experienced in studying plant FA. The median values of FA varied significantly among the participants, from 0.000 to 0.074, and the coefficients of variation in FA for individual leaves ranged from 25% to 179%. The overall reproducibility of the results among the participants was rather low (0.074. Variation in instruments and methods used by the participants had little effect on the reported FA values, but the reproducibility of the measurements increased by 30% following exclusion of data provided by seven participants who had modified the suggested protocol for leaf measurements. The scientists working with plant FA are advised to pay utmost attention to adequate and detailed description of their data acquisition protocols in their forthcoming publications, because all characteristics of instruments and methods need to be controlled to increase the quality and reproducibility of the data. Whenever possible, the images of all measured objects and the results of primary measurements should be published as electronic appendices to scientific papers.

  18. Spatial and Temporal Variation in Feather Moss Associated Nitrogen Fixation in Coniferous and Deciduous Dominated Alaskan Boreal Forests

    Science.gov (United States)

    Jean, M.; Mack, M. C.; Johnstone, J. F.

    2015-12-01

    Dominant canopy tree species have strong effects on the composition and function of understory species. In boreal forests, forest floor bryophytes and their associated microbes are a primary source of ecosystem nitrogen (N) inputs, and thus an important process regulating ecosystem productivity. Bryophyte composition and abundance varies with forest composition, yet how such changes can affect ecosystem processes such as N fixation is still poorly understood. Our goal is to investigate how cyanobacteria-based N fixation occurring in the two most common feather mosses in the Alaskan boreal forest (Pleurozium schreberi and Hylocomium splendens) varies among coniferous and deciduous forest types, over the growing season, and across a nutrient availability gradient. Twelve patches of H. splendens and P. schreberi were identified in three pairs (blocks) of adjacent stands of paper birch (Betula neoalaskana) and black spruce (Picea mariana) near Fairbanks, interior Alaska. Sampling occurred in one block in June, July, August, and September 2014, and in the three blocks once in August 2014. Moss leaf area, moisture and weight, as well as environmental variables such as air temperature and canopy cover were recorded. Fixation rates were consistently higher for P. schreberi than for H. splendens. Overall, N fixation rates were lower in birch than in spruce stands and peaked in August, or July for P. schreberi in birch stands. Moreover, fixation rates varied along the nutrient availability gradient, with fixation rates higher where nutrient availability was lower. This difference was especially clear in spruce stands. Our preliminary results suggest that moss species, canopy type, and environmental factors all influence N fixation rates in Alaskan boreal forests. Our results will enhance the knowledge of the processes that drive N fixation in boreal forests, which is important for predicting ecosystem consequences of changing forest composition.

  19. Bud flush phenology and nursery carryover effect of paper birch provenances

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    Dhar A

    2015-12-01

    Full Text Available Paper birch (Betula papyrifera Marsh is an ecologically valuable species with a broad geographic distribution across the North America. Its diversity, versatility and enduring nature make it an ideal candidate for a selective breeding program in this region. However, an understanding of the genecology of this species is fundamental to deploy it successfully. Ten paper birch provenances were collected from British Columbia (BC, Canada and northern Idaho (USA along elevational transects to determine whether observed bud flush phenology was due to genetics and /or environmental variation or their interaction. Seedlings were grown at three different nurseries: University of Idaho (46°44’N, Landing (50°17’N and Little Forestry (54°00’N and planted in a randomized single tree interlocking block design in three common gardens at Sandpoint, ID (48°13’N, Skimikin, BC (50°45’N and Red Rock, BC (53°45’N. Results indicate that variation in the timing of bud flush is a complex interaction among local genetic characteristics and environmental conditions of the growing site. Birch bud flush followed a general geographic trend where provenances at the southern common garden (Sandpoint required less time (Day of Year, DoY and fewer growing degree days (GDD compared to central (Skimikin and northern (Red Rock common gardens. Although there were significant differences in the timing of bud flush among provenances along an elevational gradient, none of the regions showed the expected linear elevational cline, trends were inconsistent. Further, birch bud flush was significantly influenced by nursery displacement effects in the initial year of establishment but disappeared within three years. These results provide an opportunity to characterize bud flush phenology of paper birch and would be useful for improving operational paper birch seed transfer programs in BC.

  20. Effects of elevated CO2 leaf diets on gypsy moth (Lepidoptera: Lymantriidae) respiration rates.

    Science.gov (United States)

    Foss, Anita R; Mattson, William J; Trier, Terry M

    2013-06-01

    Elevated levels of CO2 affect plant growth and leaf chemistry, which in turn can alter host plant suitability for insect herbivores. We examined the suitability of foliage from trees grown from seedlings since 1997 at Aspen FACE as diet for the gypsy moth (Lymantria dispar L.) Lepidoptera: Lymantriidae: paper birch (Betula papyrifera Marshall) in 2004-2005, and trembling aspen (Populus tremuloides Michaux) in 2006-2007, and measured consequent effects on larval respiration. Leaves were collected for diet and leaf chemistry (nutritional and secondary compound proxies) from trees grown under ambient (average 380 ppm) and elevated CO2 (average 560 ppm) conditions. Elevated CO2 did not significantly alter birch or aspen leaf chemistry compared with ambient levels with the exception that birch percent carbon in 2004 and aspen moisture content in 2006 were significantly lowered. Respiration rates were significantly higher (15-59%) for larvae reared on birch grown under elevated CO2 compared with ambient conditions, but were not different on two aspen clones, until larvae reached the fifth instar, when those consuming elevated CO2 leaves on clone 271 had lower (26%) respiration rates, and those consuming elevated CO2 leaves on clone 216 had higher (36%) respiration rates. However, elevated CO2 had no apparent effect on the respiration rates of pupae derived from larvae fed either birch or aspen leaves. Higher respiration rates for larvae fed diets grown under ambient or elevated CO2 demonstrates their lower efficiency of converting chemical energy of digested food stuffs extracted from such leaves into their biosynthetic processes.