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Sample records for betula

  1. 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.

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

    Institute of Scientific and Technical Information of China (English)

    杨永富; 侯丽君; 魏占才; 宋关玲

    2000-01-01

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

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

    Science.gov (United States)

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

    2015-06-01

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

  4. 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.

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

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

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

  6. 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..

  7. 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.

  8. 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.

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

    Science.gov (United States)

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

    2014-12-01

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

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

    Science.gov (United States)

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

    2017-03-06

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

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

    Science.gov (United States)

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

    2011-06-01

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

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

    Science.gov (United States)

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

    2013-06-01

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

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

    Science.gov (United States)

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

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2017-03-01

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

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2011-11-01

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

  19. 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

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

    Science.gov (United States)

    Theriault, Gabriel; Nkongolo, Kabwe

    2016-08-01

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

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

    Institute of Scientific and Technical Information of China (English)

    WEIJi-cheng; YANGChuan-ping; WANGChao; JIANGJing

    2005-01-01

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

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    Olga V. Yatsenko

    2014-04-01

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

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

    Science.gov (United States)

    Lewis, Jeffrey; Qvarfort, Ulf; Sjöström, Jan

    2015-01-01

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

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

    Science.gov (United States)

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

    2011-11-01

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

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

    Science.gov (United States)

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

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

  7. 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.

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

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    Chang Su

    2014-12-01

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

  9. 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.

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

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    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.

  11. 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.

  12. 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.

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

    Science.gov (United States)

    Deslippe, Julie R; Simard, Suzanne W

    2011-11-01

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

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

    Science.gov (United States)

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

    2017-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Lin Chen

    2016-12-01

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

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

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    Carsten Ambelas Skjøth

    2015-12-01

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

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

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    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

  18. 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.

  19. 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.

  20. 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.

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

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    Chao Wang

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

  2. 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.

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

    Science.gov (United States)

    Arbellay, Estelle; Stoffel, Markus; Bollschweiler, Michelle

    2010-10-01

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

  4. 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.

  5. 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.

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

    Science.gov (United States)

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

    2012-09-25

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

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

    Science.gov (United States)

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

    2002-02-04

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

  8. [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.

  9. 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

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

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    Wei Hao

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

  11. 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...

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

    NARCIS (Netherlands)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2015-06-01

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

  14. 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.

  15. 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...

  16. 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.

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

    Science.gov (United States)

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

    2002-12-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  1. 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. 

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

    Science.gov (United States)

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

    2011-10-01

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

  3. 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.

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

    Science.gov (United States)

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

    2008-01-01

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

  5. 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.

  6. 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

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

    Institute of Scientific and Technical Information of China (English)

    赵喆; 刘延文; 纪福利; 刘晓兰; 贾忠奎; 马履一

    2016-01-01

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

  8. 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.

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

    Science.gov (United States)

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

    2011-08-01

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

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

    Science.gov (United States)

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

    2011-11-01

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

  11. 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.

  12. 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.

  13. 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.

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

    Science.gov (United States)

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

    2008-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  16. 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

    2014-01-01

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

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

    OpenAIRE

    2012-01-01

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

  18. 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)

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

    2013-01-01

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

  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, 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

  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, 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

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

    Science.gov (United States)

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

    2016-09-01

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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    卫晶; 赵惠玲; 毕润成; 苗艳明

    2012-01-01

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

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

    Science.gov (United States)

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

    2014-11-01

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

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

    Science.gov (United States)

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

    2015-08-01

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

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

    OpenAIRE

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

    2008-01-01

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

  9. [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

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

    Directory of Open Access Journals (Sweden)

    P. Collen

    2004-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-10-15

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

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

    Science.gov (United States)

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

    2010-07-01

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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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}.

  18. 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.

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

    Science.gov (United States)

    Truong, C; Palmé, A E; Felber, F

    2007-01-01

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

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

    Science.gov (United States)

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

    2010-07-01

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

  1. Isolation of methyl syringate as a specific aflatoxin production inhibitor from the essential oil of Betula alba and aflatoxin production inhibitory activities of its related compounds.

    Science.gov (United States)

    Jermnak, Usuma; Yoshinari, Tomoya; Sugiyama, Yasumasa; Tsuyuki, Rie; Nagasawa, Hiromichi; Sakuda, Shohei

    2012-02-15

    Methyl syringate was isolated from the essential oil of Betula alba as an aflatoxin production inhibitor. It inhibited aflatoxin production of Aspergillus parasiticus and Aspergillus flavus with IC(50) values of 0.9 and 0.8 mM, respectively, without significantly inhibiting fungal growth. Methyl syringate reduced mRNA levels of genes (aflR, pksA, and omtB) [corrected] encoding proteins required for aflatoxin biosynthesis. Methyl gallate, methyl 3,4,5-trimethoxybenzoate, and methyl 3-O-methylgallate inhibited both aflatoxin production and fungal growth of A. parasiticus and A. flavus. However, their acids and syringic acid did not inhibit aflatoxin production and growth of A. parasiticus significantly, although gallic acid inhibited aflatoxin production of A. flavus with selectivity. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of methyl syringate was much weaker than that of gallic acid. These results showed that methyl syringate has a unique inhibitory activity toward aflatoxin production with a different mode of action from that of gallic acid.

  2. 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;

  3. 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

  4. 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.

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

    Science.gov (United States)

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

    2008-12-01

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

  6. Study on Growth Volume of Different Provenances of Betula alnoides Plantation%不同种源西南桦人工林生长量研究

    Institute of Scientific and Technical Information of China (English)

    袁莲珍; 史富强; 许林红; 刘际梅

    2012-01-01

    Using Excel and DPS data software Duncan multiple comparisons, the DBH, tree height and volume of 25 provenances of Betula alnoides in Puwen Experimental Farm were analyzed, results showed that: DBH, tree height and growth volume of five years different provenances Belula alnoides had the remarkable difference, the growth curve of two years tended to be linear, growth curve of four years and five years tended to be waveform: Provenance E (Tianyang of Guangxi province) had the largest growth volume, the next is provenance K (Lancang of Yunnan) : and in the four years, the smallest is the provenance A ( Linyun of Cuangxi) : in the five years, the smallest is the provenance J ( Mojiang of Yunnan).%对普文试验林场的25个不同种源西南桦子测林测定胸径、树高、材积等生长性状,利用Excel和DPS数据软件Duncan进行数据分析.结果表明:不同种源西南桦5a生时胸径、树高和材积存在着显著差异,生长曲线在2 a生时近趋于直线;在4 a生和5 a生时生长曲线呈波形;生长量最大的是种源E(广西田阳),其次是种源K(云南澜沧);4 a生时生长量最小的是种源A(广西凌云),5a生时生长量最小的是种源J(云南墨江).

  7. 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.

  8. Diarylheptanoids from leaves of Betula platyphylla%白桦叶中的二苯基庚烷类化合物

    Institute of Scientific and Technical Information of China (English)

    王素娟; 裴月湖

    2001-01-01

    目的对白桦叶的化学成分做系统研究,以更好的开发利用我国的植物资源。方法采用硅胶柱、凝胶柱及制备薄层色谱法进行分离,通过波谱技术(1HNMR,13CNMR,1H-1HCOSY,HMQC,HMBC,NOESY)进行结构鉴定。结果分离鉴定了4种二苯基庚烷类化合物,槭木素丁(Ⅰ),氧杂二苯庚烯(Ⅱ),17-甲基-15-甲氧基-7-氧代槭木素丁(Ⅲ),槭木素十一(Ⅳ)。结论化合物Ⅲ,Ⅳ均首次从本种植物中分离得到,并纠正了化合物Ⅲ的碳谱数据归属。%Object To study the chemical consti tuents of Betula platyphyllaSuk. for the better deve-lopmen t an d utilization of botanic resources of our country. Methods The constituents were isolated by column chromatography (silica gel and Sephadex LH 20) and preparative TLC, and identified by means of spectral data (1HNMR, 13CNMR, 1H-1HCOSY, HMQC, HMBC, NOESY). Resu lts 4 diarylheptanoids were obtained and elucidated as acerogenin E (Ⅰ ), (3R)-3, 5′-dihydroxy-4′-methoxy-3′, 4″-oxo-l, 7-diphenyl-l-hep te ne (Ⅱ), 15-methoxy-17-O-methyl-7-oxoacerogenin E (Ⅲ), ac erogenin K (Ⅳ). Conclusion Compounds Ⅲ and Ⅳ were isolated for the first time from this plant and the assignment of 13CNMR data o f compound Ⅲ was corrected.

  9. [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.

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

    Directory of Open Access Journals (Sweden)

    Lisa Öberg

    2012-01-01

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

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

    Science.gov (United States)

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

    2007-03-01

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

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

    Science.gov (United States)

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

    2017-04-01

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

  13. [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.

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

    Science.gov (United States)

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

    2012-06-01

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

  15. 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

  16. Four Novel Cellulose Synthase (CESA Genes from Birch (Betula platyphylla Suk. Involved in Primary and Secondary Cell Wall Biosynthesis

    Directory of Open Access Journals (Sweden)

    Xuemei Liu

    2012-09-01

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

  17. 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 .

  18. 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.

  19. 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

  20. 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

  1. Benefits in Mixed Forest of Cunninghamia lanceolata and Betula luminifera%杉木光皮桦混交林效益的研究

    Institute of Scientific and Technical Information of China (English)

    黄承标; 邓绍林; 农必昌

    2001-01-01

    对桂西北杉木光皮桦混交林和杉木纯林的对比研究表明,35年生杉桦混交林的立木蓄积量为441.087 m3*hm-2,比杉木纯林高3.6%。混交林枯枝落叶层现存量及其N,P,K,Ca,Mg等元素的质量浓度分别为13.18 t*hm-2,158.3,6.1,16.5,86.3和32.3 kg*hm-2,分别比杉木纯林高9.7%,76.7%,69.4%,96.4%,83.2%,17.0%。混交林地(0~100 cm)土壤容重为0.81~1.22 g*hm-3,比杉木纯林低1.0%~8.0%,而土壤孔隙度,通气度和持水量分别比杉木纯林高2.0%~3.9%。土壤有机质、全氮、水解氮、有效磷和速效钾分别比杉木纯林高5.5%~49.8%。%Comparative studies were conducted on mixed forest of Cunninghamia lanceolata and Betula luminifera and pure Cunninghamia lanceolata forest in westren of Guangxi.The result showed that the growing stocks in stands of 35-year-old mixed forest was 441.087 m3*hm-2,which was by 3.6% higher than those of the same years old forests of pure Cunninghamia lanceolata.The mean standing crop of litteron forest floor in mixed forest was 13.18 t*hm-2 and the mass concentration of N,P,K,Ca,Mg were 158.3,6.1,16.5,86.3,32.3 kg*hm-2,respectively.Being by 9.7%,76.7%,69.4%,96.4%,83.2%,17.0% higher than that of pure Cunninghamia lanceolata forest,respectively.In mixed forest,the soil volume weight (0~100 cm) were 0.81~1.22 g*cm-3,were 1.0%~8.0% lower than that of pure Cunninghamia lanceolata,but it total poresity aeration porosity and moisture capacty were 2.0%~3.9% higher than that of pure Cunninghamia lanceolata,respectively.The nutrientconcentration of organic matter,TN,hydrolazable N,available P and repidly available K in the soil,being by 5.5%~49.8% higher than that of pure Cunninghamia lanceolata,respectively.

  2. 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.

  3. 长白山北坡岳桦林线变动的水热条件分析%Water and Heat Changes of Betula ermanii Treeline on Northern Slope of Changbai Mountains

    Institute of Scientific and Technical Information of China (English)

    王晓东; 刘惠清

    2011-01-01

    近50年来长白山北坡林线种群呈现明显的扩张态势.为揭示林线变动机制,本文以长白山天池气象站的气象数据(1953-2007年)为基础,结合野外的气温观测,以温暖指数(WI)及湿润指数(WI)为生态气候指标,以16℃·月和68.8mm/℃·月为阈值,通过数据保证率的计算推测55年来长白山北坡岳桦林线的水热条件变化.结果表明:以WI和HI指标确定的林线位置分别在1975~2460 m和1584~2231m.WI与HI变化对林线高度变动影响的交互作用不显著(P>0.05),WI与HI变化呈显著负相关(P<0.01),两种林线变化也呈负相关(r=0.11<0),交互作用和相关分析结果显示水热条件的不同步变化使岳桦林线上侵不能达到各自的潜在高度,林线位置波动在1975~2231m.林线上缘波动的复杂程度高于下缘,波动幅度与胁迫力的大小呈正相关.%The treeline of Betula ermanii population had an obviously expanding trend on the northern slope of the Changbai Mountains in recent 50 years. In order to examine the changing mechanism of treeline, in this study, based on the data from Tianchi meteorological station (2624 m altitude) regarded as a referencing site (1953-2007) and the air temperature field measurement, using two eco-climatic preferences which were warmth index (WI) and humid index (HI), the ecotone boundary between Betula ermanii and tundra on the northern slope of the Changbai Mountains was determined by assurance ratio. The results were calculated by using the thresholds at 16 ℃· month and 68.8 mm/℃·month, and they showed that the two treelines were at 1975-2460 m and 1584-2231 m respectively. The interaction influence of WI and HI changes on treeline was not significant (p>0.05). There was a significant negative correlation between WI and HI change (p<0.01). In addition, there was a negative correlation between two treelines changes (r =-0.11<0). The results of correlation and interaction analysis indicated that the

  4. 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.

  5. Characteristics of nutrient contents and storages i n Castanopsis hystrix and Betula alnoides%红椎和西南桦营养元素的含量与储量特征

    Institute of Scientific and Technical Information of China (English)

    谭玲; 何友均; 覃林; 陈绍志

    2015-01-01

    Nutrient elements in different organs of the plant and different contents or storages of nutrient elements in the same organs,not only reflect the plant’s own biological characteristics,but also reflect the plant under certain habitats capacity to absorb and accumulation of mineral from soil.To illustrate the characteristics of nutrient element contents and storages of different valuable local forestation hardwood species in the southern subtropical area of Chi-na,we studied the contents and storages of five nutrient elements (N,P,K,Ca and Mg)in Castanopsis hystrix and Betula alnoides from the Experimental Centre of Tropical Forestry of Chinese Academy of Forestry located in Pingx-iang,Guangxi.We have got some meaningful results from collecting plant samples,laboratory test and statistical a-nalysis method.The total contents of these five nutrient elements in different organs of Castanopsis hystrix and Bet-ula alnoides were in the order of leaf>fine root>twig>medium root>thick root>bark>root tip>stem.The con-tents of N and K were the highest among the five elements,followed by Ca and Mg,while P was the lowest in various organs of the two trees.The contents of N and P in leaf were significantly higher than those in other organs for Cas-tanopsis hystrix and Betula alnoides (Ptwig>bark>leaf>thick root>fine root>medium root.The nutrient utilization effi-ciency of Castanopsis hystrix was slightly higher than that of Betula alnoides.The study revealed that the nutritional requirements of Castanopsis hystrix and Betula alnoides would provide theoretical basis for adj usting and improving the two trees growing environment,as well as making forest land nutrient management strategies.%营养元素在植物不同器官及不同营养元素在同一器官中的含量与储量特征,不仅反映植物自身的生物学特性,而且还反映了植物在一定的生境下从土壤中吸收和蓄积矿质养分的能力.为了阐明我国南亚热带不同珍优乡土阔叶造

  6. The Selection of Reference Genes for Quantitative PCR in Betula luminifera%光皮桦实时荧光定量PCR内参基因的筛选

    Institute of Scientific and Technical Information of China (English)

    刘文哲; 牛明月; 李秀云; 林二培; 黄华宏; 童再康

    2016-01-01

    [Objective]Real-time quantitative PCR ( RT-qPCR) has become the preferred approach to the quantification of gene expression. Besides its simplicity and efficiency,this method requires suitable reference genes to guarantee the accuracy of the quantification. Betula luminifera is not only a high-quality timber species with excellent wood properties, but also an ideal species for genetic study. Stability of candidate reference genes in different tissues was investigated using RT-qPCR and expression analysis software to select suitable reference genes,the reliability of the reference genes was further verified through expression analysis of two functional genes in different tissues. [Method]16 housekeeping genes were chosen as candidate reference genes,and specificity of the primers was investigated by agarose gel electrophoresis and melting curve of target amplified fragments. The software of geNorm,NormFinder and BestKeeper were used to analyze expression stability of reference genes in 16 different tissues. Furthermore,two functional genes were selected to verify the reliability of the suitable reference genes. [Result]Electrophoresis results showed distinct PCR products with the expected size,and the single-peak melting curves further indicated the specificity of the selected primers. Except 18S,the Ct values of the candidate genes were all between 25 to 30 ,indicating the expressions of these candidate genes were quite stable in different tissues. EF1α was characterized as the most stable gene based on NormFinder and BestKeeper analysis, while TATA was ranked in the first place according to geNorm. UBi-lp showed the most unstable expression. Furthermore, three top-stable genes ( EF1α,TATA and UBi4 ) and the unstable gene UBi-lp were chosen to verify the reliability of the reference genes. As results,the two target genes showed consistent expression profiles when normalized by the three top-ranked reference genes,and UBi-lp failed to standardize the expression

  7. Population Structure Dynamics of Betula luminifera Secondary Forest in Jixi County of Anhu i Province, China%绩溪光皮桦次生林的种群动态1)

    Institute of Scientific and Technical Information of China (English)

    万志兵; 程国源; 丁强强; 方乐金

    2014-01-01

    对绩溪光皮桦次生林种群进行了调查,以种群生命表及生存分析理论为基础,以林木径级结构代表龄级结构,编制了绩溪光皮桦种群静态生命表,分析绩溪光皮桦次生林种群结构的动态变化特点。结果表明:光皮桦种群结构呈纺锤型,幼龄个体数量偏少,中龄个体数居多,而老龄个体则相对数量较少,说明种群有衰退的趋势;在第Ⅴ龄级时该种群出现死亡高峰,其种群存活曲线属 Deevey-Ⅱ型;绩溪光皮桦次生林种群具有前期种群数量少,中期稳定,末期衰退的特点。%The experiment was conducted to determine population structure dynamic and quantitative statistics of Betula luminif-era in a secondary forest of Jixi county, Anhui Province.By the population life table and survival analysis, the life table of Betula luminifera population was constructed and age classes were replaced with size-classes, therefore, the population structure dynamic of B.luminifera was explored.The results of the population structure illustrates a spindle type with a gradually decline in population.The individual plants of class I and class II are not enough.The survival curve in the pop-ulation is a Deevey-Ⅱtype with a peak of mortality in size class V.The population size ofB .luminifera declines sharply in early stage, stabilizes in middle stage and falls rapidly in last stage.

  8. Study on Anatomy and Physiology of Graft Healing Process in‘P .armeniaeae f olia/P .betulae f olia’%‘杏叶梨/杜梨’嫁接愈合过程的解剖学与生理学研究

    Institute of Scientific and Technical Information of China (English)

    黄曼娜; 孙华丽; 宋健坤; 杨英杰; 王然

    2014-01-01

    针对‘杏叶梨(Pyrus armeniacaefolia/杜梨(Pyrus betulifolia)’嫁接组合出现的“小脚”现象,以杜梨自体嫁接(杜梨/杜梨)为对照,进行了愈合过程解剖结构观察及生理变化分析,以探讨梨嫁接亲和性机理。结果表明:杏叶梨的材皮比显著小于杜梨;砧穗嫁接愈合过程解剖学观测可大致分为4个阶段,分别为隔离层形成、愈伤组织形成、砧穗愈伤组织相互接触及分化和新输导组织形成;‘杏叶梨/杜梨’嫁接口愈合速度滞后‘杜梨/杜梨’6d;与‘杜梨/杜梨’自体嫁接对照相比,‘杏叶梨/杜梨’嫁接口处多酚氧化酶(PPO )与苯丙氨酸解氨酶(PA L )活性变化幅度较大,除个别观测点(嫁接后18d)外,PPO活性大部分时期高于‘杜梨/杜梨’;木质素含量在两种嫁接组合的愈合后期均表现增加趋势,但‘杜梨/杜梨’增加趋势更明显;‘杜梨/杜梨’可溶性糖含量高峰早于‘杏叶梨/杜梨’;两种嫁接组合可溶性蛋白含量变化趋势相近,但‘杜梨/杜梨’嫁接口可溶性蛋白含量显著高于‘杏叶梨/杜梨’。%On the scion overgrowing phenomenon of ‘P . armeniaeae f olia/P .betulae f olia’ in field ,the P .betuli f olia antilogous grafting was taken as contrast and the mechanism of graft compatibility was dis-cussed by observing the effects of cicatrization on the anatomical structures and analyzing the physiological change of graft union .The results revealed that the ratio of wood and bark of P .armeniaeaefolia was sig-nificant less than P .betulae f olia .Observing the anatomical structures of graft union ,we found that the graft healing process was approximately divided into 4 stages ,which were the insulating layer forming , callus forming ,connecting and differentiating of callus of the scion and stock ,and the conducting tissue forming respectively .On the rate of cicatrization of graft union ,

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

    Science.gov (United States)

    Zhou, Chenguang; Li, Chenghao

    2016-01-01

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

  10. 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.

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

    Science.gov (United States)

    Pająk, Marek; Halecki, Wiktor; Gąsiorek, Michał

    2017-02-01

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

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

    Science.gov (United States)

    Czernicka, Małgorzata; Pławiak, Jarosław; Muras, Piotr

    2014-01-01

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

  13. 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

  14. 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.

  15. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-02-15

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

  17. Construction and analysis of a subtracted cDNA library of Betula platyphylla female inflorescence%白桦雌花序cDNA消减文库的构建及分析

    Institute of Scientific and Technical Information of China (English)

    魏继承; 杨传平; 王超; 姜静

    2005-01-01

    为研究白桦雌花序花期基因表达情况,以两天为间隔对其进行取样.基于SMART策略,通过RT-PCR,将源自最后时期样品的cDNA作为Driver cDNA,源自其他时期样品的cDNA作为Tester cDNA,构建抑制性消减文库.EST序列经blastX分析表明,该文库中的基因大致可以归为五类,分别同代谢、物质运输和信号转导、细胞周期、胁迫反应及调控相关.本文对基因表达同发育的关系做了探讨.%Female inflorescence of Betula platyphylla was sampled at an interval of each two days to analyze the background of gene expression in floral phase. On the basis of SMART strategy, the driver cDNA was obtained from total RNA of the last sample and the tester cDNA was from that of the others by RT-PCR which were subsequently used to construct a subtracted cDNA library. The result of the ESTs (expression sequence tags) blastX showed that the genes in the subtracted cDNA library could be mainly clustered into 5 groups related to metabolism, transportation and signal transduction, cell cycle, stress response, and regulation. The relationship between gene expression and development was also discussed.

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

    Science.gov (United States)

    Zhang, W; Zwiazek, J J

    2016-11-01

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

  19. Solar UV-B effects on PSII performance in Betula nana are influenced by PAR level and reduced by EDU: results of a 3-year experiment in the High Arctic.

    Science.gov (United States)

    Albert, Kristian R; Mikkelsen, Teis N; Ro-Poulsen, Helge; Arndal, Marie F; Boesgaard, Kristine; Michelsen, Anders; Bruhn, Dan; Schmidt, Niels M

    2012-07-01

    The long-term and diurnal responses of photosystem II (PSII) performance to near-ambient UV-B radiation were investigated in High Arctic Betula nana. We conducted an UV exclusion experiment with five replicated blocks consisting of open control (no filter), photosynthetic active radiation and UV-B transparent filter control (Teflon), UV-B-absorbing filter (Mylar) and UV-AB-absorbing filter (Lexan). Ethylenediurea (EDU), a chemical normally used to protect plants against ozone injury, was sprayed on the leaves both in the field and in an additional laboratory study to investigate if EDU mitigated the effects of UV-B. Chlorophyll-a fluorescence induction curves were used for analysis of OJIP test parameters. Near-ambient UV-B radiation reduced across season maximum quantum yield (TR(o) /ABS = F(v) /F(m)), approximated number of active PSII reaction center (RC/ABS) and the performance index (PI(ABS)), despite improved leaf screening against UV-B with higher content of UV-B-absorbing compounds and a lower specific leaf area. EDU application counteracted the negative impact of UV-B on TR(o) /ABS, RC/ABS and PI(ABS) . This indicates that the mechanisms behind UV-B and ozone damage share some common features. The midday depression was present in all treatments, but TR(o) /ABS and PI(ABS) were persistently lower in near-ambient UV-B compared to UV-B reduction. The recovery phase was particularly impaired in near-ambient UV-B and interactive effects between treatment × hour raised TR(o) /ABS, RC/ABS and PI(ABS) higher in reduced UV-B compared to near-ambient UV-B. This demonstrates current solar UV-B to reduce the PSII performance both on a daily as well as a seasonal basis in this High Arctic species.

  20. Effects of Drought Stress on Photosynthesis & Content of Osmoregulation Substance for Betula maximowicziana%干旱胁迫对真桦光合特性及渗透调节物质含量的影响

    Institute of Scientific and Technical Information of China (English)

    王晓冬; 李蕴峰; 刘宇明

    2012-01-01

    Using potted seedlings of Betula maximowicziana as material,an experiment was conducted to study the effects of drought stress on photosynthesis content of osmoregulation substance.Result shows that: net photosynthetic rate(P_n),transpiration rate,stomatal conductance(G_s) in seedlings of B.maximowicziana were significantly decreased by drought stress;decreased range increase with the increased levels of stress.At initial stage of the stress,G_s intercellular CO_2 content(C_i) decrease with the decrease of the P_n in group of slight or medium drought stress;photosynthesis reduction is mainly due to stomatal factor;for the metaphase or late stage,a decreasing P_n with higher C_i indicated that non-stomatal factor is the leading limitation.Soluble sugar in seedlings of B.maximowicziana increased under soil moisture stress,but non-significant change in soluble protein;soluble sugar is the main osmoregulation substance.%以真桦盆栽幼苗为试材,研究干旱胁迫对真桦叶片光合作用和渗透调节物质含量的影响。结果表明:干旱胁迫使真桦幼苗净光合速率、蒸腾速率和气孔导度显著降低,降低幅度随胁迫程度的加剧而加大。胁迫初期,轻度和中度干旱胁迫组真桦幼苗净光合速率降低的同时气孔导度和胞间CO2浓度同时降低,光合速率降低的主要原因是气孔因素;胁迫中期和后期,各干旱处理组光合速率降低的同时胞间CO2浓度均显著升高,非气孔限制是净光合速率降低的主要原因。真桦在干旱胁迫过程中,可溶性蛋白变化不显著,可溶性糖含量增加,为主要的渗透调节物质。

  1. 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.

  2. Effects of Nitrogen Deposition on Soil Nitrogen Mineralization of Betula platyphylla Forest in Daxing ’ an Mountains%施氮量对大兴安岭白桦次生林土壤氮矿化的影响

    Institute of Scientific and Technical Information of China (English)

    包翔; 包秀霞; 刘星岑

    2015-01-01

    以大兴安岭白桦天然次生林为研究对象,分析施氮量对土壤氮矿化的影响。结果表明,白桦次生林土壤中铵态氮、硝态氮和有效氮质量分数在生长季间存在显著差异。总体上,土壤中有效氮素质量分数在7月份最高,5月份最低。白桦次生林土壤中铵态氮、硝态氮和有效氮质量分数均随着氮沉降量的增加而增加;同时氮沉降也显著增加了土壤氨化速率、硝化速率和氮矿化速率,其中氨化速率的增幅大于硝化速率的增幅。不同施氮处理下,净矿化速率与土壤有机碳质量分数间的相关性比与全氮质量分数间更为密切。%In a natural secondary forest of Betula platyphylla in Daxing’ an Mountains, we studied the effects of nitrogen deposi-tion on soil nitrogen mineralization.The contents of NH4-N, NO3-N and available N were significant differences among the growing seasons.Available N content was the highest on July and the lowest on May.The contents of NH4-N, NO3-N, available N, soil ammonification rate, nitrification rate and nitrogen mineralization rate were significantly increased with the increasing of N deposition.The ammonification rate of increase was greater than the nitrification rate.Under different N contents, the correlation ratio between the soil organic carbon and total N net mineralization rate was higher than total N.

  3. Effects of N exponential fertilization on nutrient loading and photosynthesis of Betula platyphylla seedlings%氮素指数施肥对白桦播种苗养分承载和光合作用的影响

    Institute of Scientific and Technical Information of China (English)

    郝龙飞; 刘婷岩; 张连飞; 贾斌英; 李宁; 李开隆

    2014-01-01

    为改善白桦苗木质量,本文采用常规施肥( CF)、指数施肥( EF)、1/2指数施肥( HEF)、2倍指数施肥( DEF)以及对照( CK)处理,研究容器苗中不同N施肥处理对白桦1年生播种苗生物量分配、养分含量动态和养分承载以及苗木叶片光合能力的影响。结果表明:1)生长结束后,EF处理提高了苗木生物量,同时改善了苗木根系生物量所占比例。 EF处理苗木总生物量较CK提高23.87%(P0.05)。 EF处理苗木叶面积高于CF处理14.3%(PDEF>HEF>CF>CK。 EF处理有效促进了苗木生物量积累,提高了苗木养分承载,同时明显提高了苗木体内P、K的养分利用效率,因此EF处理为最佳施肥方式。%In order to improve Betula platyphylla seedling quality, the biomass allocation, nutrient ( N, P, K) content dynamics, nutrient loading and leaf photosynthesis of B. platyphylla container seedlings under constant ( CF) , exponential ( EF) , half exponential ( HEF) and doubled exponential fertilization ( DEF) regimes and control (CK) were studied in the first year growing. Results showed that:1) at the end of the growing season, EF treatment improved the biomass of seedlings and the biomass proportion of root. The total biomass of seedlings under EF treatment was greater than that under CK ( P 0. 05) respectively. Meanwhile, seedling leaf area under EF treatment was greater than that under CF treatment in 14. 3%. 4) The concentration of N, P and N, K nutrient under 5 fertilization treatments was linear correlation. Exponential fertilization improved the P, K uptake efficiency ( EF>DEF>HEF>CF>CK) in seedlings. EF reffectively promoted biomass accumulation and improved nutrient loading, meanwhile, significantly increased P, K utilization. EF is the best fertilization regime for B. platyphylla seedlings.

  4. The Dynamics Response of Betula ermanii Population and Climate Change on Different Slopes Aspect of North Slope,Changbai Mountains%长白山北坡林线岳桦种群动态对气候变化响应的坡向分异

    Institute of Scientific and Technical Information of China (English)

    王晓东; 刘惠清

    2012-01-01

    To discover the relation between Betula ermanii population dynamics and climate change on treeline ecotone of Changbai Mountains,53 plots were selected on three different slope aspects(northeast,southeast,east slopes) through treeline ecotone on north slope of Changbai Mountains.Distributing character of the diameter-class(diameter at breast height(DBH)) structure of shrub and single-trunk forms were described by four aggregation indices.Trend analysis of distributing character was carried through by unitary linearity equations.Different reflection of the dynamics response of Betula ermanii population to climate change on different slope aspects was analyzed by stepwise regression and correlation analysis.The results are as follows:the results of trend analysis of the diameter-class distributing(slopes of equations are negative) shows the capacity expansion rate of shrub form is east slopes〉southeast slopes〉northeast slopes and that of single trunk form is northeast slopes〉east slopes〉southeast slopes.The population expansion is leapfrog and pulsatile from low to high(p〉0.01).The result of One-way ANOVA displays that daily mean temperature on three slopes are significant differences(p〈0.05) and the temperature change has synchronism.The results of correlation analysis between annual stem recruitment of Betula ermanii population and 14 ecological preferences of air temperature(1953-2008) show that the different response of population dynamics to climate change caused by different temperature on three slopes.The difference of climate change lead to different expansion of Betula ermanii population on different positions.%选取长白山北坡岳桦(Betula ermanii)苔原交错带3个不同坡向(东北坡、东南坡、东坡)的岳桦径级结构为研究对象,分析坡向在岳桦种群动态与气候变化之间关系的异同。结果表明:三坡向的岳桦种群扩张和气温高低存在明显差异。14个

  5. Spatiotemporal dynamics of seed rain in natural forest of Betula alnoides in Jingxi County,Guangxi, China%广西靖西西南桦天然林种子雨的时空动态

    Institute of Scientific and Technical Information of China (English)

    郭俊杰; 赵志刚; 欧景莉; 沙二; 林开勤; 曾杰; 徐大平

    2012-01-01

    Aims Our objective was to study spatiotemporal dynamics of seed dispersal of Betula alnoides and analyze its correlation with wind speed and wind direction at community and individual levels. Methods Seed dispersal was investigated for a natural forest and an isolated tree of B. alnoides. We set seven sample lines 100 to 355 m long in or around the natural forest. One seed trap was placed every 5 m, and seeds were collected every two days. We set eight sample lines (east, southeast, south, southwest, west, northwest, north, northeast) around the isolated tree. Three seed traps were placed every 5 m from 0 to 50 m and every 10 m from 60 to 150 m, and seeds were collected each day. Wind speed and wind directions were measured at two sites. Seed rain density was calculated. Important findings The seed rain lasted 83 and 60 days at the community and individual levels, respectively. The starting, fastigium and subsiding stages of seed dispersal lasted 11,32 and 40 days for the community and 9, 25 and 26 days for the isolated individual. Seeds dispersed at the fastigium stage accounted for 83.1% and 68.7% of all seeds collected at the community and individual levels, respectively. Seed rain density was higher during the day than at night, and the highest seed rain density by day occurred at 12:00-16:00. At the individual level, seed rain density decreased with increasing distance from the maternal tree, and 79.6% of seeds were collected in the area of 0-30 m around the maternal tree. Seed rain density at the community level also decreased with longer distance from the forest edge, and 79.6% of seeds were collected in the area of 0-45 m around the forest edge. The seed rain density was significantly different among directions (p < 0.01), which was affected by wind direction. Seed rain density was also positively affected by wind speed (p < 0.05).%以一片西南桦(Betula alnoides)天然林和一个西南桦独立单株为研究对象,通过收集散种期内与林分或

  6. Isolation and Expression of Flowering Locus T (FT) Gene in Betula platyphylla%白桦开花位点Flowering Locus T(FT)基因的分离及其表达

    Institute of Scientific and Technical Information of China (English)

    马丽丽; 邱丽丽; 付扬威; 荆瑞瑞; 刘雪梅

    2012-01-01

    FT及其同源基因在促进植物成花和发育阶段转变过程中起重要作用.应用RT-PCR和RACE技术分离了白桦FT基因的cDNA,全长为928 bp,其开放阅读框为525 bp,编码174个氨基酸.预测的蛋白质分子量为19.6kDa,理论等电点为7.73.该预测蛋白序列含有保守的PEBP蛋白结构域,命名为BplFT,并在GenBank注册,登录号为JQ409561.该基因序列同其它16种植物的相似性为74% ~ 93%,其中与无花果(Ficus carica)的相似度最高为93%,与拟南芥(Arabidopsis thaliana)的相似度最低为74%,并构建了该基因序列的进化树.通过qRT-PCR的方法检测BplFT基因在白桦不同时期不同组织中的转录表达,在营养器官的表达高于花器官,成熟组织要高于幼嫩的组织,在成熟茎中的表达量最高,推测BplFT基因在成熟的营养器官发育中起重要作用,并可能参与调控次生细胞壁的形成.另外,选择了白桦雄花序突变体进行该基因的转录表达分析,该基因在突变体雌花序、雄花序、幼叶及幼茎中均为上调表达,预示着BplFT基因不仅仅参与营养组织发育,在花器官发育中也具有一定的作用.%Flowering Locus T ( FT) gene and its homologues play an important role in promotion flowering plants and changes in developmental stage. The full cDNA of FT gene was isolated from Betula platyphylla Suk. by methods of reverse transcription polymerase chain reaction ( RT-PCR) and 5' and 3' rapid amplification of cDNA ends (RACE) . Results showed that FT gene contains an open reading frame (ORF) of 525 bp encoding 174 amino acids. Molecular weight of the deduced protein of BplFT is 19. 6 kDa and the theoretical isoelectric point is 7.73. The FT conserved protein domain of PEBP was confirmed in the sequence, so the isolated gene was named as BplFT, and registered in GenBank with accession number JQ409561. The deduced amino acid sequence shared 74% -93% of identity with other sixteen plant species, the maximum

  7. 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

  8. 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.

  9. 光皮桦茎叶cDNA文库构建及部分EST序列SSR分析%Library construction of cDNA and SSR analysis of partial ESTs for stem and leaf of Betula luminifera

    Institute of Scientific and Technical Information of China (English)

    张敏; 黄华宏; 林二培; 周厚君; 王亚辉; 童再康

    2012-01-01

    A cDNA library of stem and leaf from Betula luminifera was constructed.The primary titer of cDNA library was about 1.5×106 pfu/mL,its recombinant efficiency reached 97.3%,and the size of insert DNA fragments ranged from 0.5 to 3.0 kb,with an average of 1.3 kb.The results indicated that it was a higher-quality cDNA library,and could be used in gene cloning and gene expression profile analysis.Distribution and frequency of SSRs were analyzed in 224 non-redundant ESTs from B.luminifera cDNA library,using online searching software.The results showed that 60 SSRs distributed in 47 EST sequences,accounting for 26.80% of all ESTs.Dinucleotide would be the major repeat types,accounting for 70.00% of the total number of acquired SSRs.The tri-nucleotide and tetra-nucleotide repeats accounted for 28.30% and 1.70% respectively.This research might lay the foundation for designing the targeted EST-SSR primers and genetic diversity analysis by mining the information of EST-SSR loci in B.luminifera EST sequence data.%以光皮桦茎叶组织为材料,构建了cDNA文库。初级文库滴度为1.5×106pfu/mL,重组率达97.3%,插入片段大小在0.5~3.0kb之间,平均长度约为1.3kb,表明所构建的文库质量较高,可用于后续基因克隆及基因表达谱的研究。利用微卫星查找软件对获得的224条EST序列进行微卫星位点搜寻及其丰度、分布比较,发现47条序列含微卫星位点60个,占全部EST序列的26.80%;在所有SSRs中二碱基重复最多,为42个,占总数的70.00%,含三、四碱基重复分别占总数的28.30%和1.70%。通过对光皮桦EST序列中微卫星位点信息的发掘分析,为有针对性地设计EST-SSR引物、进行遗传多样性分析奠定了基础。

  10. ALLOZYME DIVERSITY IN NATURAL POPULATIONS OF BETULA ALNOIDES FROM GUANGXI, CHINA%广西区西南桦天然居群遗传多样性的研究

    Institute of Scientific and Technical Information of China (English)

    曾杰; 王中仁; 周世良; 郑海水; 白嘉雨

    2003-01-01

    以采自广西区11个西南桦(Betula alnoides)天然居群的种子培育出的幼苗为材料,取其嫩叶开展21种酶系统的水平切片淀粉凝胶电泳实验,运用作者改进的Tris-马来酸提取缓冲液 (含30%PVP 40 000和1%2-巯基乙醇),筛选出AMP(氨基肽酶Aminopeptidase)、FBA(果糖二磷酸酶Fructose-bisphosphate aldolase)、GDH(谷氨酸脱氢酶Glutamate dehydrogenase)、G6PD(6-磷酸葡萄糖脱氢酶Glucose-6-phosphate dehydrogenase)、IDH(异柠檬酸脱氢酶Isocitrate dehydrogenase)、MDH(苹果酸脱氢酶Malate dehydrogenase)、PGD(6-磷酸葡萄糖酸脱氢酶Phosphogluconate dehydrogenase)、PGI(磷酸葡萄糖异构酶Phosphoglucoisomerase)、PGM(磷酸葡萄糖变位酶Phosphoglucomutase)和SKD(莽草酸脱氢酶Shikimate dehydrogenase)等10种酶,获得了清晰且可重复的酶谱.通过谱带遗传分析确定了15个位点,其中有6个单态位点,9个多态位点 (0.95标准),具40个等位基因.在居群水平上,西南桦的多态位点百分数 (P) 为55.2%,平均每个位点的等位基因数 (A) 为2.00,平均预期杂合度 (He) 为0.204.均超过Hamrick (1992)等提出的远交风媒木本植物的平均值(53.0%,1.84%和0.154),表明西南桦的遗传变异水平高.在11个西南桦居群内,实际杂合度 (Ho)均高于预期杂合度,出现杂合子过量,可能存在利于杂合子的自然选择.西南桦遗传多样性与地理位置相关不显著.居群2 (靖西地州)、5 (平果海城)、9 (田林者苗) 包含绝大部分的等位基因,而且具较高的遗传多样性,应加以保护和管理,作为其基因资源就地保存的基地.本研究解决了以西南桦嫩叶为材料进行等位酶分析的关键技术,为进一步开展西南桦乃至桦木属树种的遗传结构和遗传多样性等提供了技术基础;同时掌握了西南桦天然居群的遗传多样性现状,为其有效保护和合理经营以及西南桦的遗传改良提供了理论依据.

  11. 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

  12. 粤北西南桦种源试验林星天牛危害分析与早期综合评价%Hazard Analysis of Anoplophora chinensis and Early Comprehensive Selection of Betula alnoides Provenances in Northern Guangdong Province

    Institute of Scientific and Technical Information of China (English)

    赵志刚; 张朝斌; 丘英华; 郭俊杰; 何永佳; 翁启杰; 曾杰

    2011-01-01

    Betula alnoides Buch. -Ham. Ex D. Don is a fast-growing and precious tree species in tropical and warm subtropical regions. The wood borer damage has recently been one of key factors limiting the large-scale expansion of B. Alnoides plantations. A trial including 26 provenances and 322 families were established at Shaoguan State-owned Forest Farm in northern Guangdong Province, which were suffered from heavy damage of wood borers within two years after planted. The growth performance and resistances to wood borers of B. Alnoides were investigated for the purpose of early selection of germplasm. The results showed that there were significant differences among prove-nances in height and base diameter (P 0. 05) , and the mean attack rates for one-year-old and two-year-old B. Alnoides trees were 48. 21% and 36. 27% , respectively. Early selection of B. Alnoides provenance was carried out based on its growth performance and the attack rate by the wood borers. These findings could be contributive to understand the occurrence of A. Chinensis, protect from its damage, and provide evidences to select germplsm of B. Alnoides with good growth performance and strong resistance to A. Chinensis in northern Guangdong and surrounding areas with similar environment.%西南桦(Betula alnoides Buch.-Ham.Ex D.Don)是我国热带南亚热带地区的一个优良乡土阔叶树种[1-2],在云南、广西、广东等地被广泛应用于珍贵用材林基地建设,是该区域造林面积最大的乡土阔叶树种之一[2].西南桦木材可用于制作木地板、高档家具以及室内装饰等[3],而且人工林具维持生物多样性、涵养水源、保持地力以及较高的固碳能力等优良生态特性[2],在用材林、生态公益林等建设中具有重要的地位和发展潜力.经过二十多年的研究,西南桦的良种选育和栽培技术已取得显著成果,促进了人工林的发展,但在西南桦推广种植过程中,尤其是近几年来,蛀干害虫的

  13. 华西雨屏区亮叶桦凋落叶分解对模拟氮沉降的响应%Response of Betula luminifera leaf litter decomposition to simulated nitrogen deposition in the Rainy Area of West China

    Institute of Scientific and Technical Information of China (English)

    涂利华; 胡红玲; 胡庭兴; 张健; 雒守华; 戴洪忠

    2012-01-01

    Aims Our objective was to determine the effect of simulated increased nitrogen (N) deposition on decomposition of Betula luminifera leaf litter, under a high wet-nitrogen deposition background.Methods From January 2008 to February 2009, a field experiment of simulated N deposition was conducted in a B. Luminifera plantation in the Rainy Area of West China. The levels of nitrogen deposition were control (CK), low, medium and high N (0, 5, 15 and 30 g Nm-2·a-1, respectively). A field experiment using the litterbag method was conducted on the decomposition of leaf litter of B. Luminifera. In the end of each month, NH4NO3 was added into N-treated plots.Important findings Despite the high background N deposition, there were significant effects of simulated increased N deposition on B. Luminifera leaf litter. N treatments significantly slowed the decomposition of B. Luminifera leaf litter through inhibiting the decay of lignin and cellulose. The time of 95% mass loss (r95%) of B. Luminifera leaf litter was increased by 1.14-1.96 a from 2.65 a (T95o/o of CK) caused by simulated N deposition. Simulated N deposition significantly increased the remaining amount of carbon, N, phosphorus, potassium, and magnesium after one year of decomposition. However, calcium release rate was stimulated by simulated N deposition in all three N treatments. The initial chemical characteristics of litter determined the response direction of litter decomposition to simulated N deposition, as well as the nutrient release pattern during litter decomposition.%从2008年1月至2009年2月,对华西雨屏区亮叶桦(Betula luminifera)人工林进行了模拟氮(N)沉降试验,N沉降水平分别为对照(CK,0gN·m-2·a-1)、低N(5 gN·m-2·a-1)、中N(15 g N·m-2·a-1)和高N(30g N·m-2·a-1).利用凋落袋法对亮叶桦凋落叶进行原位分解试验,并在每月下旬定量地对各处理施N (NH4NO3).结果表明,虽然华西雨屏区大气N沉降量较高,但模拟N沉降试验表明:在N

  14. 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.

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

    Science.gov (United States)

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

    2002-12-01

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

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

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    夏磊; 吴福忠; 杨万勤; 谭波

    2012-01-01

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

  18. Analysis on diameter structure of the mixed forest of Larix principis-rupprechtii Mayr.and Betula platyphylla Suk.in Mengluan Forestry Farm%河北省孟滦林场落叶松白桦混交林直径结构分析

    Institute of Scientific and Technical Information of China (English)

    崔丽红; 兰永生; 王丽华; 陈永军; 黄选瑞

    2012-01-01

    Stand diameter structure, as the most basic and important stand structure, means the distribution status of all kinds of trees with different diameters in a stand. The knowledge of the stand diameter structure is to clearly understand the results from single wood growth and stand competition. The research on the rules of dynamic changes of stand diameter structure will contribute more benefits to revealing the essence of stand development rule. The article investigates all the plants with>3 cm DBH in the mixed forest of Larix Principis-rupprechtii Mayr. and Betula platyphylla Suk. in the Mengluan Forestry Farm, Mulan Forestry Administration as research object by using sample plot method, and analyzes the distribution characteristics of diameter structure of main tree species with the statistical software Forstat2. 1. The statistic analysis shows the largest number of trees appears in the middle diameter class and the smaller number of trees in the small diameter class, with poor stand regeneration. Based on the integrated effect of normal distribution, gamma distribution, logarithmic normal distribution, binomial distribution and Poisson distribution, the forest diameter distribution law is supposed to be better reflected.%林分直径结构是林分内各种大小直径林木的分配状态,它是最基本也最重要的林分结构.了解林分的直径结构,也就对单木生长以及林分竞争所产生的结果有了清楚的认识;探讨林分直径结构动态变化规律更是有利于揭示林分发展规律的实质[1].本研究以木兰林管局孟滦林场华北落叶松白桦混交林为研究对象,采用标准地调查法对林内胸径大于3 cm的林木进行每木检尺,并使用Forstat2.1统计软件对主要树种直径结构分布规律进行研究,研究发现,各树种处于中间径阶的林木株数最多;小径阶林木较少,林分更新较差;综观拟合效果,正态分布、伽玛分布、对数正态分布、二项分布以

  19. 不同盐梯度处理下沼泽小叶桦的生理特征及叶片结构%Photosynthetic Performance and Variation in Leaf Anatomic Structure of Betula microphylla var.paludosa under Different Saline Conditions

    Institute of Scientific and Technical Information of China (English)

    王斌; 巨波; 赵慧娟; 张群; 朱义; 崔心红

    2011-01-01

    设计盐梯度(0,2‰,4‰,6‰,8‰盐溶液的质量比为NaCl∶ Na2SO4∶ NaHCO3=75%∶15%∶10%)试验分析沼泽小叶桦生理表现和叶片解剖结构.结果显示:在低于4‰盐度时沼泽小叶桦能正常生长,6%‰盐度时沼泽小叶桦生长发育不良,当盐度8‰时沼泽小叶桦只能存活30天左右;在低盐度处理下沼泽小叶桦光合生理表现和叶片解剖结构正常;随着盐度增加,其叶片净光合速率、气孔导度、胞间CO2浓度、蒸腾速率、叶绿素含量等指标均下降,而叶片中可溶性糖含量、脯氨酸含量、蛋白质含量升高;当盐度≥0.4%时,沼泽小叶桦叶片栅栏细胞逐渐纵向伸长且排列更紧密,叶绿体从椭圆形变成球形,叶绿体中出现粗大的淀粉粒和脂质球,表明其对滨海盐土具有一定的适应能力.%Betula microphylla var. Paludosa is a salt tolerant plant and naturally grows in inland. In order to explore possibility in transplanting the species to marine salina, we investigated photosynthetic performance and leaf anatomic structure of B. Microphylla , grown under control (nutrient soil) or salt-stress conditions (nutrient soil containing different salinity; 2‰, 4‰, 6‰, 8‰ of the solution for 60 days. The species had normal photosynthetic performance and leaf anatomic structure under lower salinity conditions. When soil salinity increased (≥0. 4%) , the net photosynthesis rate, stomatal conductance, transpiration rate, internal CO2 concentration, and chlorophyll content in leaves all decreased, whereas the soluble sugar, proline and protein contents of leaf increased. Accordingly, cells of the palisade tissue in B. Microphylla var. Paludosa leaf elongated and piled closely, in comparison with that under lower salinity conditions, and the chloroplasts changed from elliptical shape to round shape and in which many 1 ipid droplets and starch grains occurred in it. These results indicated that B. Microphylla var

  20. 大兴安岭北部白桦次生林林内积雪及浅层土壤温度分布特征1)%Characteristics of Temperature in Snow-cover and Shallow-soil in Betula platyphylla Secondary Forests in the Northern Daxing’ an Mountains

    Institute of Scientific and Technical Information of China (English)

    朱宾宾; 满秀玲; 王树力; 俞正祥

    2015-01-01

    We studied the characteristics of temperature in snow-cover and shallow-soil by locating observation in Betula platyphylla secondary forest in the northern Daxing ’an Mountains.With the increasing of the snow depth , snow-cover had greater difference of temperature , when the snow depth was in 11.36-140.0 cm and air temperature was 13.10℃ , and the temperature diversity between snow-bottom and snow-surface was6 .89℃, however, when the depth of snow reached up to 275.-30 cm and the air temperature lowered to -30.20℃, then, the temperature diversity between snow-bottom and snow-surface got to 18.87℃.As air temperature cooled to 17.10℃, the snow-surface temperature cooled 17.31℃, snow-bottom temperature only cooled 5.34℃, which showed that certain thick snow had thermal effect on snow-bottom temperature , and the thicker the snow was , the greater insulated effect became .With the increasing of the snow depth , snow-cover had grea-ter difference of temperature-gradient, when the snow depth was 132.5 cm, the temperature-gradient diversity between the upper and lower was 0.17℃/cm, nevertheless, when the depth of snow reached up to 29.80 cm, the temperature-gradient difference soared to 0.65℃/cm, which showed that when cold air passed through the topsnow , and showed the cooling effect on subsnow .The snow-cover delayed the transmission of cold air to the subsoil , when the depth of snow was 11.36-14 cm, shallow-soil cooled 2.59℃on condition that air temperature cooled 6℃;when the depth of snow rose go up to 26.00-34.80 cm, shallow-soil merely cooled 2.63℃on condition that air temperature cooled 8℃.The thicker snow-cover was , the more obvious snow-cover sluggished the invasion of cold air to soil .Under 12.46 cm snow-cover , the temperature-gradient were 0.26℃/cm and 0.13℃/cm in soil-layers of 0-10 cm and 20-30 cm, respectively .When the snow depth was 30.22 cm, the temperature-gradients of 0-10 cm and 20-30 cm soil-layers were 0.31 and 0

  1. Xylem Characteristics of Tension Wood and Endogenous Hormones Distributions during Its Early Formation Period in Betula luminifera%光皮桦应拉木的显微特征及其形成早期内源激素分布

    Institute of Scientific and Technical Information of China (English)

    何辉; 楼雄珍; 林二培; 俞友明; 童再康; 黄华宏

    2016-01-01

    【目的】分析光皮桦应拉木的显微结构、理化特性及其形成早期的内源激素分布,以期为揭示应拉木形成机制提供理论依据。【方法】以无性系1V25-2为材料,通过人工拉弯诱导形成应拉木,测定其主要显微特征和物理化学特性,并应用 ELISA分析其形成早期阶段主要内源激素的分布规律。【结果】经12个月的拉弯处理,应拉区木质部的细胞壁明显增厚,纤维平均双壁厚是对应木的1.8倍,形成明显的胶质纤维层。应拉木的平均纤维长度、纤维素含量均明显大于对应木,而木质素含量则相反。拉弯处理的早期阶段,不同木质部类型中的4种激素含量呈现不同的分布特征。应拉区木质部中 IAA含量均小于对应区,但仅处理7天的木质部样品两区块间差异达到显著水平。GAs(GA1+GA3)也表现出与 IAA类似的变化规律。除拉弯处理6 h的样品外,应拉区木质部 BR 含量均显著小于对应区和对照,且随着处理时间延长对应区木质部 BR含量呈递增趋势。ZR含量在应拉区和对应区木质部间皆无明显差异,但表现出随处理时间延长而增加的趋势,处理7天时2区块的 ZR 含量均显著高于对照。【结论】经12个月的拉弯处理,光皮桦应拉区木质部的细胞壁明显增厚,出现明显的胶质纤维层;平均纤维长度、纤维素含量增加,表现出特有的理化特征。在拉弯处理早期阶段,4种内源激素在木质部中的含量呈现出不同的分布变化,推测这些激素的重新分布可能与光皮桦应拉木的形成有一定关系。%Objective]Reaction wood is one of the limiting factors for efficient cultivation and wood utilization of fast-growing timber species. There are various types of tension woods ( TWs) in Betula luminifera plantation,but the research on their characteristics and forming causes is absent. In this study,microscopic structure

  2. 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.

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    Smolibowska Joanna

    2016-09-01

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

  5. 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.

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

    Science.gov (United States)

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

    2004-08-01

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

  7. 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.

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

    Science.gov (United States)

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

    2011-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Lucyna Pawłowska

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Eetu ePuttonen

    2016-02-01

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

  11. 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.

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

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    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.

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

    Science.gov (United States)

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

    2014-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-12-01

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

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

    Science.gov (United States)

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

    2008-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Lucyna Pawłowska

    2014-01-01

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

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

    Science.gov (United States)

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

    2016-12-01

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

  18. 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.

  19. 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.

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

    Science.gov (United States)

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

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

  1. 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.

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

    NARCIS (Netherlands)

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

    1999-01-01

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

  3. 西南桦苗木生长对微波辐射和IBA浸种的响应%Growth Response of Betula alnoides Seedlings to Microwave Radiation and IBA Soaking Seeds Treatment

    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

    采用裂区试验设计,分别以有无微波辐射和IBA浸种为主区和副区进行西南桦苗木培育试验.结果表明:西南桦苗木的地径和苗高生长对微波、IBA及其二者间的交互作用都具有积极的响应.苗龄120天时,苗木平均地径在有和无微波前提下,均以IBA浓度250 mg/L溶液浸种最大(分别为0.60、0.78 mm);150天时,微波辐射、无IBA溶液浸种平均地径最大,达1.19 mm;而2个苗期的苗木平均高均以微波辐射、不采用IBA浸种的最高,分别为12.39、16.10 cm; 150天时,微波辐射的平均地径(0.70 mm)较无微波辐射的地径(0.41mm)大;120时,微波辐射的苗平均高(6.58 cm)的大于无微波(4.98 cm)的平均苗高;150天,微波辐射的平均苗高(8.16 cm)的大于无微波(5.78 cm)的平均苗高.

  4. Cloning of BplAGL Related to Floral Development of Betula platyphylla%白桦中一花发育相关基因BplAGL的克隆及时序表达分析

    Institute of Scientific and Technical Information of China (English)

    魏继承; 任如意; 国会艳; 宗宪春; 郝爱平; 杨传平

    2010-01-01

    对白桦花序进行分期取材,CTAB法提取总RNA,基于SMART(Switching Mechanism At 5' end of RNA Transcript)策略进行cDNA合成,根据现有EST序列设计基因特异性引物,通过RACE(rapid amplification of cDNA end)手段克隆了一花发育相关基因--BplAGL,使用TreeTOP工具对其系统发生进行了评价.采用外标实时定量PCR分析其花期时序表达模式,认为BplAGL可能属于D功能基因.

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

    Institute of Scientific and Technical Information of China (English)

    张军; 柴永江; 杨敏生

    2006-01-01

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

  6. 白桦提取物对大鼠下丘脑组织中5-HT含量的影响*%Effect Betula HaatyphyHa suk(BPS) Extract on 5- HT Hypothalamus of Rats

    Institute of Scientific and Technical Information of China (English)

    杜旭; 刘璐; 薛欣

    2001-01-01

    目的研究白桦提取物对酵母致大鼠发热的影响及对下丘脑组织中5-HT含量的影响.为其解热降温机理作用提供依据.方法用荧光分光光度计在480nm/365nm处测定5-HT含量.单位以每mg鲜脑组织含5-HT的ng数表示.结果酵母模型组大鼠体温及下丘脑组织中5-HT含量均明显高于正常对照组,给药组大鼠给予白桦提取物后1h体温显著下降,下丘脑组织中5-HT含量亦明显降低.讨论本实验结果显示:白桦提取物对酵母致发热大鼠有明显的解热作用,其解热作用与影响体温调节中枢介质5-HT的含量有关.

  7. Leaf Litter Decomposition and Its Relationship with Soil Properties in Betula alnoides and Eucalyptus urophylla ×E.grandis%西南桦和尾巨桉凋落叶分解及其与土壤性质的相关性

    Institute of Scientific and Technical Information of China (English)

    郝建; 莫慧华; 黄弼昌; 周燕萍; 蔡道雄

    2016-01-01

    Compared with the E.urophylla ×E.grandis stand,the B.alnoides had significantly higher contents of soil or-ganic carbon (SOC),total N,total P,total K as well as higher N /P ratio in 0 -1 0 and 1 0 -20 cm soil depth. However,the litter decomposition had no significant effects on SOC,total K,pH,C /N ratio and N /P ratio in 20-30 cm soil depth.The correlation analysis revealed that the organic C of leaf litter was significantly related to SOC,total N,total P,total K and N /P ratio,whereas the total N of leaf litter was significantly related to soil total N,pH and C /N ratio.[Conclusion]The nutrient contents of leaf litter were found to be significantly correlated with the soil nutrient condition.Compared with the E.urophylla ×E.grandis,the nutrient contents of leaf litter were significantly higher in B.alnoides,and subsequently,faster decomposition rate of leaf litter resulted in high-er soil nutrient contents.%[目的]探讨南亚热带西南桦和尾巨桉人工纯林的凋落叶分解动态及其与土壤化学性质之间的相关关系。[方法]采用原位分解袋法研究凋落叶的分解过程。[结果]表明:西南桦、尾巨桉人工林凋落叶分解系数分别为0.96 a -1和0.88 a -1。在为期12个月的分解试验中,2种凋落叶有机 C 含量在整个分解过程中呈逐渐下降趋势;全K 含量和 C /N 比在分解前期迅速下降,之后趋于平缓;全 N 含量和全 P 含量在整个分解过程中呈逐渐上升趋势;2种凋落叶 N /P 比则呈先升高后下降的趋势。无论是分解前期还是分解后期,凋落叶质量损失与 N 含量均呈显著正相关(前期 R =0.877;后期 R =0.855),与 C /N 均呈显著负相关(前期 R =-0.735;后期 R =-0.697)。与尾巨桉林地土壤性质相比,西南桦凋落叶分解提高了林地010、1020 cm 土壤的有机 C、全 N、全 P、全 K、N /P,对2030 cm 土壤有机 C、全 K、pH 值、C /N、N /P 则未产生显著影响。相关分析表明:凋落叶初始有机 C 含量与土壤有机C、全 N、全 P、全 K、N /P 显著相关;凋落叶初始全 N 含量与土壤全 N、pH 值、C /N 显著相关。[结论]凋落叶的养分含量与土壤养分的关系紧密;与尾巨桉相比,西南桦凋落叶的养分含量明显较高,分解速率更快,释放到土壤中的养分也更多。

  8. EFFECT OF SIMULATED NITROGEN DEPOSITION ON SOIL RESPIRATION IN Betula Platyphylla FOREST IN SOUTH OF DAXING'ANLING MOUNTAINS IN CHINA%氮沉降对大兴安岭南段白桦林土壤呼吸的影响

    Institute of Scientific and Technical Information of China (English)

    邱睿; 魏江生; 周梅; 赵鹏武; 颜学佳; 刘星岑

    2015-01-01

    近年来随着人类活动导致全球范围内大气氮沉降量开始增加,竟而改变了陆地生态系统氮的输入,并影响到了土壤碳排放.为揭示氮沉降对土壤呼吸的影响,2013年5月至9月在大兴安岭南段的赛罕乌拉森林生态站白桦林内进行模拟氮沉降试验,使用便携式土壤CO2通量观测仪LI-8100测定不同人工添加氮浓度[CK(0)、LN(10kg·hm-2·a-1)、MN(25kg·hm-2·a-1)和HN(50kg·hm-2·a-1)]对土壤呼吸的影响.结果表明:①氮沉降处理未显著改变土壤呼吸速率的日变化和季节性变化规律;②氮沉降显著促进了白桦林土壤呼吸速率,与CK相比,HN、MN和LN处理分别使7月中旬土壤日平均呼吸速率提高了17.93%、11.67%和3.50%,使生长季土壤平均呼吸速率提高了42.48%、30.09%和16.52%;③土壤呼吸与温度呈极显著的指数相关(P<0.01),CK、HN、MN和LN处理下,土壤呼吸温度敏感系数Q1o分别为2.43、2.13、2.52和2.31.

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

    Science.gov (United States)

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

    2015-11-01

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

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

    DEFF Research Database (Denmark)

    Heliasz, Michal; Johansson, Torbjörn; Lindroth, Anders

    2011-01-01

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

  11. 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,

  12. General Classification Handbook for Floodplain Vegetation in Large River Systems. Chapter 1 of Book 2, Collection of Environmental Data

    Science.gov (United States)

    2004-01-01

    tuberculatus WM Amorpha A. fruiticosa WMS Betula B. nigra FF, LF Bidens B. cernua, B. frondosa SMA Carex C. spp.1 SM Carya C. cordiformis, C. illinoensis LF...include pecan ( Carya ), hickory ( Carya ), river birch (Betula), sycamore (Platanus), and red/black oak (Quercus). This general class is most com- mon...near the edge of the floodplain, or out of the floodplain. This general class typi- cally consists of red or white oak (Quercus), hickory ( Carya

  13. Biophysical feedbacks between the Pleistocene megafauna extinction and climate: The first human-induced global warming?

    Science.gov (United States)

    Doughty, Christopher E.; Wolf, Adam; Field, Christopher B.

    2010-08-01

    A large increase in Betula during a narrow 1000 year window, ˜13,800 years before present (YBP) in Alaska and Yukon corresponded in time with the extinction of mammoths and the arrival of humans. Pollen data indicate the increase in Betula during this time was widespread across Siberia and Beringia. We hypothesize that Betula increased due to a combination of a warming climate and reduced herbivory following the extinction of the Pleistocene mega herbivores. The rapid increase in Betula modified land surface albedo which climate-model simulations indicate would cause an average net warming of ˜0.021°C per percent increase in high latitude (53-73°N) Betula cover. We hypothesize that the extinction of mammoths increased Betula cover, which would have warmed Siberia and Beringia by on average 0.2°C, but regionally by up to 1°C. If humans were partially responsible for the extinction of the mammoths, then human influences on global climate predate the origin of agriculture.

  14. Clone and Analysiso f ReverseT ran script ase of Ty1-copia-like Retrotransposon s in Betula platyphly la under Sodi-um Nitroprusside (SNP) and Methyl Jasmonate (MeJA) Treatment%硝普钠(SNP)和茉莉酸甲酯(MeJA)诱导的白桦Ty1-copia类逆转座子的克隆及分析

    Institute of Scientific and Technical Information of China (English)

    梁楠松; 曾凡锁; 李博; 郭梁; 詹亚光

    2013-01-01

    We designed the primers of reverse transcriptase according to the conserved domains of the Ty1-copia retrotransposons reverse transcriptase.We obtained several fragments of reverse transcriptase from callus of birch by using improved RT-PCR.Eleven and nine fragments were amplified from callus of birch treated by sodium nitroprusside ( SNP) and methyl jasmonate (MeJA), respectively.The length of 21 reverse transcriptase sequences (named Bprt 1-21) is from 205 to 290 bp, with the consistency of 71.93%, the heterogeneity of from 1.1% to 50.9% and the heterogeneity of amino acid se-quences of from 0.0% to 57.1%.The sequences from birch treated by SNP or MeJA are clustered, respectively.The transcription of Ty1-copia-like retrotransposons can be activated by different signals.The analysis of the phylogenetic tree of reverse transcriptase of Ty1-coip a-like retrotransposons between birch and apple revealed each of the reverse transcripta-ses are clustered together, but the evolutional relationship between Bprt9, Bprt11 and DQ410750 are closer.Bprt15, Bprt19, DQ410751 and DQ410753 are clustered together.Therefore, the horizontal transmission can exist in retrotrans-posons.%利用 Tyl-copia类逆转座子逆转录酶( RT)的保守区域设计引物,优化了扩增条件后利用RT-PCR从白桦愈伤组织中得到了1条逆转录酶序列。利用硝普钠( SNP)和茉莉酸甲酯( MeJA)诱导后分别扩增克隆了11条和9条逆转录酶序列。这21条逆转录酶序列(命名Bprt1-21)变化范围为205~290 bp,一致性为71.93%,异质性为11.%~50.9%,翻译成氨基酸的异质性为0~57.1%。经SNP和MeJA处理的样品中,获得的逆转录酶序列基本是分别聚类,初步证明不同的Ty1-copia类逆转座子能够分别响应不同的信号而被转录激活。分析所获得的21逆转录酶序列和苹果中19条逆转录转座子序列( DQ410748~DQ410766)进化关系发现,逆转录酶基本各自聚类,但是Bprt9、Bprt11和DQ410750进化关系比较接近,Bprt15、Bprt19、DQ410751和DQ410753聚为一类,证明逆转座子存在水平传递。

  15. 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.

  16. 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 ...

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

    Science.gov (United States)

    Weber, Günther; Konieczyński, Paweł

    2003-04-01

    Aqueous extracts of birch leaves ( folium Betulae), peppermint leaves ( folium Menthae), sage leaves ( folium Salviae), valerian roots ( radix Valerianae), and dandelion roots ( radix Taraxaci) are analysed for the three essential elements magnesium, manganese and zinc. Ultrafiltration reveals that 60-100% of these metals are present as low molecular weight species (complexation.

  18. National Wetland Plant List Indicator Rating Definitions

    Science.gov (United States)

    2012-07-01

    cut grass), Acorus americanus (sweetflag), Carex aquatilis (leafy tussock sedge ), and Toxicodendron vernix (poison sumac). FACW (Facultative Wetland...where water saturates the soils or floods the soil surface at least seasonally. Examples include Carex scoparia (broom sedge ), Aconitum columbianum...Ambrosia artemisifolia (annual ragweed), Betula papyrifera (paper birch), Carex eburnea (bristle-leaf sedge ), Carya ovata (shag-bark hickory), Elymus

  19. Dicty_cDB: FC-IC1683 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available equence. 44 0.16 2 CD269836 |CD269836.1 T143A02135F (FHIG:A) Ectomycorrhiza plate...70770.1 T143A01691F (FHIG:A) Ectomycorrhiza plate culture Betula pendula/Paxillus involutus mixed EST librar

  20. 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...

  1. 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

  2. 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

  3. 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=

  4. 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

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  6. Mechanisms to Detoxify Selected Organic Contaminants in Higher Plants and Microbes, and Their Potential Use in Landscape Management

    Science.gov (United States)

    2004-10-01

    intracellular spaces → cell walls of cortical cells → endodermis → diffusion through the casparian strip ( suberized barrier) → xylem. If organic compounds...Bald cypress (Taxodium distichum) River bitch (Betula nigra) Cherry-bark oak ( Quercus falcata) Bentazon Live oak ( Quercus viginiaga) Plants

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

    NARCIS (Netherlands)

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

    2000-01-01

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

  8. Comparative measurements of transpiration an canopy conductance in two mixed deciduous woodlands differing in structure and species composition

    DEFF Research Database (Denmark)

    Herbst, Mathias; Rosier, Paul T.W.; Morecroft, Michael D.;

    2008-01-01

    Transpiration of two heterogeneous broadleaved woodlands in southern England was monitored by the sap flux technique throughout the 2006 growing season. Grimsbury Wood, which had a leaf area index (LAI) of 3.9, was dominated by oak (Quercus robur L.) and birch (Betula pubescens L.) and had a cont...

  9. 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

  10. Wood-inhabiting dematiaceous Hyphomycetes in the Kampinos National Park

    Directory of Open Access Journals (Sweden)

    A. Borowska

    2014-08-01

    Full Text Available In this work the results of investigations of wood-inhabiting fungal communities in several forest associations arę presented. The populations of these fungi on the wood of Carpinus betulus, Quercus robur, Betula verrucosa, Tilia cordata and Pinus sylvestris are also analyzed.

  11. Apple mosaic virus

    Science.gov (United States)

    Apple mosaic virus (ApMV), a member of the ilarvirus group, naturally infects Betula, Aesculus, Humulus, and several crop genera in the family Rosaceae (Malus, Prunus, Rosa and Rubus). ApMV was first reported in Rubus in several blackberry and raspberry cultivars in the United States and subsequentl...

  12. 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

  13. Cottonwoods of the Midwest: A Community Profile

    Science.gov (United States)

    2008-05-01

    Bitternut hickory Carya cordiformis X X Pignut hickory Carya glabra X Pecan Carya illinoensis X Shellbark hickory Carya lacinios X Shagbark...rugosa X Pawpaw Asimina triloba X River birch Betula nigra X American hornbeam Carpinus caroliniana X Water hickory Carya aquatica X...hickory Carya ovata X Mockernut hickory Carya tomentosa X Sugarberry Celtis laevigata X Hackberry Celtis occidentalis X X Eastern redbud

  14. A Regional Guidebook for Applying the Hydrogeomorphic Approach to the Functional Assessment of Forested Wetlands in Alluvial Valleys of East Texas

    Science.gov (United States)

    2010-10-01

    hickory Carya illinoensis pecan Carya spp. hickory Celtis laevigata sugarberry Celtis occidentalis hackberry Cephalanthus occidentalis...abundance were deciduous holly and red maple. Matos and Rudolph (1985) recorded overcup oak, laurel oak, sweetgum, black gum, water hickory ( Carya ...switchcane Berchemia scandens supplejack Betula nigra river birch Campsis radicans trumpet creeper Carpinus caroliniana ironwood Carya aquatica water

  15. 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

  16. Predicting tree pollen season start dates using thermal conditions.

    Science.gov (United States)

    Myszkowska, Dorota

    2014-01-01

    Thermal conditions at the beginning of the year determine the timing of pollen seasons of early flowering trees. The aims of this study were to quantify the relationship between the tree pollen season start dates and the thermal conditions just before the beginning of the season and to construct models predicting the start of the pollen season in a given year. The study was performed in Krakow (Southern Poland); the pollen data of Alnus, Corylus and Betula were obtained in 1991-2012 using a volumetric method. The relationship between the tree pollen season start, calculated by the cumulated pollen grain sum method, and a 5-day running means of maximum (for Alnus and Corylus) and mean (for Betula) daily temperature was found and used in the logistic regression models. The estimation of model parameters indicated their statistically significance for all studied taxa; the odds ratio was higher in models for Betula, comparing to Alnus and Corylus. The proposed model makes the accuracy of prediction in 83.58 % of cases for Alnus, in 84.29 % of cases for Corylus and in 90.41 % of cases for Betula. In years of model verification (2011 and 2012), the season start of Alnus and Corylus was predicted more precisely in 2011, while in case of Betula, the model predictions achieved 100 % of accuracy in both years. The correctness of prediction indicated that the data used for the model arrangement fitted the models well and stressed the high efficacy of model prediction estimated using the pollen data in 1991-2010.

  17. 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

  18. Tree and shrub expansion over the past 34 years at the tree-line near Abisko, Sweden.

    Science.gov (United States)

    Rundqvist, Sara; Hedenås, Henrik; Sandström, Anneli; Emanuelsson, Urban; Eriksson, Håkan; Jonasson, Christer; Callaghan, Terry V

    2011-09-01

    Shrubs and trees are expected to expand in the sub-Arctic due to global warming. Our study was conducted in Abisko, sub-arctic Sweden. We recorded the change in coverage of shrub and tree species over a 32- to 34-year period, in three 50 x 50 m plots; in the alpine-tree-line ecotone. The cover of shrubs and trees (tree stems (> or =3.5 cm) were noted and positions determined. There has been a substantial increase of cover of shrubs and trees, particularly dwarf birch (Betula nana), and mountain birch (Betula pubescens ssp. czerepanovii), and an establishment of aspen (Populus tremula). The other species willows (Salix spp.), juniper (Juniperus communis), and rowan (Sorbus aucuparia) revealed inconsistent changes among the plots. Although this study was unable to identify the causes for the change in shrubs and small trees, they are consistent with anticipated changes due to climate change and reduced herbivory.

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

    OpenAIRE

    Finér, Leena

    1989-01-01

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

  20. Vegetation and environmental responses to climate forcing during the Last Glacial Maximum and deglaciation in the East Carpathians: attenuated response to maximum cooling and increased biomass burning

    Science.gov (United States)

    Magyari, E. K.; Veres, D.; Wennrich, V.; Wagner, B.; Braun, M.; Jakab, G.; Karátson, D.; Pál, Z.; Ferenczy, Gy; St-Onge, G.; Rethemeyer, J.; Francois, J.-P.; von Reumont, F.; Schäbitz, F.

    2014-12-01

    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 Lateglacial vegetation dynamics in this area; however, our knowledge on the LGM vegetation composition is very 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 (with Pinus, Betula, Salix, Populus and Picea) 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 demonstrate xerophytic 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 Betula 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 support population genetic inferences regarding the regional presence of some temperate deciduous trees during the LGM (Fagus sylvatica, Corylus avellana, Fraxinus excelsior). Our sedimentological data also demonstrate intensified aeolian dust accumulation between 26,000 and 20,000 cal yr BP.

  1. 16 Pollen Allergens Differ From Nonallergenic Pollen Proteins by Their Lower Extent of Evolutionary Conservation

    OpenAIRE

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

    2012-01-01

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

  2. USSR Report, Chemistry.

    Science.gov (United States)

    2007-11-02

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

  3. Phase 2 Site Investigations Report. Volume 1 of 3: General Annex-Wide Information

    Science.gov (United States)

    1994-09-01

    Rose Rosa mudiflora Northern Arrowwood Viburnum recognitum Northern Red Oak Quercus rubra Orchard Grass Dactylis glomerata Panic Grass Panicum sp...Paper Birch Betula papyrifera Partridge-Berry Mitchela repens Pink Ladyslipper Cypripedium Poison Ivy Toxicodendron radicans Poverty Grass Danthonia ...mixture of white pine and oak is the predominant forest type in the northern portion (Figure 2-5). Open areas vegetated with grasses , forbs, and

  4. Remedial Investigations Report for Fort Devens Subbury Training Annex, Maynard, Massachusetts, Sites P11/P13 and Sites A12/P36/P37, Phase 2. Volume 1

    Science.gov (United States)

    1995-12-01

    Poverty grass Danthonia spicata X Panic grass Panicum sp. X Common Milkweed Ascelpias syriaca X X Indian Pipe Monotropa uniflora X Pink Ladyslipper...Viburnum recognitum Northern Red Oak Quercus rubra Orchard Grass Dactylis glomerata Panic Grass Panicum sp. Paper Birch Betula papyrifera Partridge-Berry...Mitchella repens Pink Ladyslipper Cypripedium Poison Ivy Toxicodendron radicans Poverty Grass Danthonia spicata Privet Ligustrum vulgare Queen Anne’s

  5. 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

  6. 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

  7. 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

  8. 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

  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: 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

  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: 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

  13. 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

  14. 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

  15. 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

  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: 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. Soil Physical and Chemical Properties of Different Forests in Burned Area of Daxing’ an Mountains after Vegeta-tion Restoration%大兴安岭火烧迹地植被恢复后土壤理化性质1)

    Institute of Scientific and Technical Information of China (English)

    辛颖; 赵雨森; 陈强

    2013-01-01

    An experiment was conducted to study the soil physical and chemical properties of four forest types in serious burned area of Daxing’ an Mountains.Soil pH of Pinus sylvestris var.mongolica plantation increased, but that of Larix gmelini plantation, Betula platyphlla natural forest and Pobulus davidiana natural forest decreased.The soil organic matter, total N, hydrolyzable N, total P and available P of Larix gmelini plantation, Betula platyphlla natural forest and Pobulus davidi-ana natural forest increased in different degree.The soilbulk density of Larix gmelini plantation, Betula platyphlla natural forest decreased, but that of Pinus sylvestris var.mongolica plantation and Pobulus davidiana natural forest increased.The soil porosity of Betula platyplh la natural forest was the best.Therefore, after vegetation restoration, Larix gmelini planta-tion, Betula platyphlla natural forest and Pobulus davidiana natural forest can improve the soil.%以大兴安岭重度火烧迹地经过植被恢复后形成的4种林分类型为研究对象,研究重度火烧迹地在经过植被恢复后,不同林分类型土壤理化学性质的变化。研究结果表明:与对照样地相比,樟子松林土壤pH值升高,兴安落叶松林、白桦林和山杨林土壤pH值均降低。兴安落叶松林、白桦林和山杨林土壤有机质、全N、水解N、全P、有效P质量分数均有不同程度的升高。兴安落叶松林和白桦林土壤密度降低,樟子松林和山杨林的土壤密度升高。白桦林土壤孔隙度最好。综合比较可以看出,大兴安岭重度火烧迹地经过植被恢复后,兴安落叶松林、白桦林和山杨林均在一定程度上改良了土壤。

  3. 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

  4. 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. 

  5. 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

  6. 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.

  7. 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.

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

    OpenAIRE

    Kumar, Hemanathan; Alén, Raimo; Sahoo, Gokarneswar

    2016-01-01

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

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

    OpenAIRE

    Morales Suárez, Luis Orlando

    2014-01-01

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

  10. 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

  11. 4 种新烟碱类内吸性杀虫剂对光肩星天牛毒力研究

    Institute of Scientific and Technical Information of China (English)

    王凤乐

    2007-01-01

    @@ 光肩星天牛(Anoplophora glabripennis)不仅严重为害中国西北地区杨树等树木,而且它也威胁美国城市树木、森林及木材等相关工业.该虫为害的主要树种有槭树(Acer spp.)、桦树(Betula spp.)、杨树(Populus spp.)、榆树(Ulmus spp.)、柳树(Salix spp.)等,在中国还发现沙枣(Elaeagnus angustifolia)也是成虫的适宜寄主.

  12. [Soil enzyme activities under two forest types as affected by different levels of nitrogen deposition].

    Science.gov (United States)

    Zhao, Yu-tao; Li, Xue-feng; Han, Shi-jie; Hu, Yan-ling

    2008-12-01

    A simulation test was conducted to study the change trends of soil cellulase, polyphenol oxidase, and sucrase activities under natural broadleaf-Korean pine (Pinus koraiensis) and secondary poplar (Populus davidiana) -birch (Betula platyphylla) mixed forests as affected by 0, 25, and 50 kg x hm(-2) x a(-1) of N deposition. The results showed that the effects of elevated N deposition on test enzyme activities varied with forest type, and short-term nitrogen addition could significantly affect the test enzyme activities. High N deposition decreased soil polyphyneol oxidase activity, and correspondingly, soil cellulase and sucrase activities also had a trend of decrease.

  13. 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

  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. Plant and microbial uptake and allocation of organic and inorganic nitrogen related to plant growth forms and soil conditions at two subarctic tundra sites in Sweden

    DEFF Research Database (Denmark)

    Sørensen, Pernille Lærkedal; Clemmensen, Karina Engelbrecht; Michelsen, Anders

    2008-01-01

    transported a high proportion of 15N to aboveground parts, whereas the dwarf shrubs allocated most 15N to underground storage. Enhanced 13C in Betula nana roots represents the first field evidence of uptake of intact glycine by this important circumpolar plant. Plant and microbial uptake of label...... was complementary as plants took up more inorganic than organic N, while microbes preferred organic N. Microbes initially took up a large part of the added label, but over the following four weeks microbial 15N decreased by 50% and most 15N was recovered in soil organic matter, while a smaller but slowly increasing...

  16. Airborne Pollen Grains in Zonguldak,Turkey,2001-2002

    Institute of Scientific and Technical Information of China (English)

    Ayse KAPLAN

    2004-01-01

    The variation in airborne pollen concentration of the Zonguldak region, Turkey was studied for two consecutive years 2001-2002 using a Durham sampler. During this period, a total of 61 304 pollen grains belonging to 43 taxa were recorded. Of these 43 taxa, 26 belonged to arboreal and 17 to nonarboreal plants. The main pollen types were Pinaceae, Populus, Carpinus, Betula, Corylus, Fagus orientalis,Castanea sativa, Alnus glutinosa, Quercus, Cupressaceae, Chenopodiaceae and Gramineae, representing 96.7% of the pollen spectrum. Pollen concentration reached the highest level in March.

  17. The pollen season dynamics and the relationship among some season parameters (start, end, annual total, season phases) in Kraków, Poland, 1991-2008.

    Science.gov (United States)

    Myszkowska, D; Jenner, B; Stępalska, D; Czarnobilska, E

    2011-09-01

    The dynamics of 15 taxa pollen seasons in Kraków, in 1991-2008 was monitored using a Burkard volumetric spore trap of the Hirst design. The highest daily pollen concentrations were achieved in the first half of May, and they were caused mainly by Betula and Pinus pollen. The second period of the high concentrations took place from the middle of July to the end of August (mainly Urtica pollen). Tree pollen seasons were shorter (18-24 days) in comparison with the most herbaceous pollen seasons (73-89 days), except at Artemisia and Ambrosia seasons (30 and 24 days, respectively). The season phases (percentyles) of the spring and late-summer taxa were the most variable in the consecutive years. The highest annual sums were noted for Urtica, Poaceae (herbaceous pollen seasons) and for Betula, Pinus, Alnus (tree pollen seasons), and the highest variability of annual totals was stated for Urtica, Populus, Fraxinus and the lowest for Ambrosia, Corylus, Poaceae. For the plants that pollinate in the middle of the pollen season (Quercus, Pinus and Rumex), the date of the season start seems not to be related to the season end, while for late pollen seasons, especially for Ambrosia and Artemisia, the statistically negative correlation between the start and the end season dates was found. Additionally, for the most studied taxa, the increase in annual pollen totals was observed. The presented results could be useful for the allergological practice and general botanical knowledge.

  18. Palynological records of environmental changes in the middle part of Inner Mongolia, China

    Institute of Scientific and Technical Information of China (English)

    SHI Peijun; SONG Changqing

    2003-01-01

    A 2.4-m-long core was extracted from Diaojiao Lake (41°18′N, 112°21′E) at the foot of the northern part of Daqingshan Mts. High-resolution pollen analysis results of two sites showed 10 arboreal genera, including Pinus, Betula, Picea, Abies, Carpinus, Quercus, Ulmus and more than 20 non-arboreal genera, mainly of Artemisia, Labiatae, Nitraria, Polygonaceae, Ranunculus, Thalictrum, Umbelliferae, Caryophyllaceae and Cyperaceae dominating the record. Fern spores, aquatic pollen and algae were also observed in some sections of the cores. The sequence was divided stratigraphically into six pollen assemblage zones by a stratigraphically-constrained cluster analysis using an incremental sum of squares method. The vegetation underwent the following stage changes: steppe with sparsetrees, steppe, forest, and steppe. During the middle Holocene, a mixed forest of Pinus, Betula and Quercus occurred on the mountainous areas, and Pinus forestdominated the frontal plains. Six climatic stages were inferred from total pollen flux and pollen percentage from the two sites using a transfer function: humid-cool (10000-7800 aBP), arid-cold (9200-7800 aBP), arid-warm (7800-7100 aBP), humid-warm (7100-4400 aBP), arid-warm (4400-3000 aBP), arid-cold (3000-2100 aBP) phases were identified.

  19. Pollen seasons of selected tree and shrub taxa in Kraków and its neighbourhood

    Directory of Open Access Journals (Sweden)

    Dorota Myszkowska

    2012-12-01

    Full Text Available The aim of the study was to compare the dynamics of pollen seasons of selected tree and shrub taxa among measurement sites in Kraków and its neighbourhood. The study was performed in Kraków and Piotrkowice Małe in 2002, as well as in Kraków and Giebułtów in 2006. During the study the volumetric method was applied and pollen grains were counted along four horizontal lines. The lowest percentage of Corylus pollen and the highest percentage of Betula pollen were found in the analysed sites. The differences among start dates in various measurement sites in a given year were inconsiderable. Statistically signifi cant differences of SPI values for the majority of taxa were found between measurement sites and between seasons for Kraków. The pollen season dynamics showed one (Betula, Pinaceae or more maximum values (Corylus, Populus, Fraxinus, Salix. The occurrence of many peaks could be explained by the appearance of several species within one genus in the studied area or by various weather conditions. In 2002 maximum pollen concentrations were recorded earlier than in 2006. The differences in these dates could be explained better by cumulative temperature >5℃ than >0℃.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-04-15

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

  1. 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.

  2. 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.

  3. [An orientational examination of the effects of extracts from mixtures of herbal drugs on selected renal functions].

    Science.gov (United States)

    Masteiková, R; Klimas, R; Samura, B B; Savickas, A; Samura, B A; Belaij, S I; Samura, I B; Rabisková, M; Chalupová, Z; Bernatoniene, J

    2007-04-01

    The paper aimed to determine the effects of mixtures of selected medicinal plants on some physiological renal functions, i.e. excretion of urine and electrolytes and changes in the quantity of prostaglandins E2 (PGE2) and kallikrein-kinins in rat blood plasma after water and salt load. The following medicinal plants were selected for the examination: downy birch (Betula pubescens EHRH.), everlasting flower (Helichrysum arenarium L. MOENCH.), hawthorn (Crataegus oxyacantha L.), woodland strawberry (Fragaria vesca L.), sweet corn (Zea mays L.), German chamomile (Matricaria recutita L.), and field horsetail (Equisetum arvense L.). Herbal drugs were used to compose 6 mixtures. Extracts from these mixtures were administered to Wistar strain males and their effects were compared with the effects of an administered suspension of hydrochlorothiazide, an extract from field horsetail herb alone, and a control group of animals which was not administered any preparation. The greatest diuretic effect was found in a mixture composed of birch leaves (Betulae folium), hawthorn berries (Crataegi fructus), strawberry leaves (Fragariae folium), corn silk (Maydis stigmata), chamomile flowers (Matricariae flos), and horsetail herb (Equiseti herba). Its effect was greater by 47% and 34% than the effect of a horsetail herb extract and a hydrochlorothiazide suspension (p < 0.05), respectively. The extract from this mixture also increased the quantity of prostaglandins E2 and kallikrein-kinins in rat blood plasma in water and salt load.

  4. 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.

  5. РАСТИТЕЛЬНОСТЬ ЗАКАЗНИКА «ЗАЛЕСОВСКИЙ» (АЛТАЙСКИЙ КРАЙ)

    OpenAIRE

    Терёхина, Татьяна; Елесова, Наталья; Копытина, Татьяна; Иванова, Мария

    2013-01-01

    Растительность заказника «Залесовский» представлена черневой тайгой со значительным участием комплекса травянистых третичных реликтов. Характерными ассоциациями растительности являются: Abies sibirica+Betula pendula–Crepis sibirica, Abies sibirica+Betula pendula–Brachypodium pinnatum+Aegopodium podagraria, Abies sibirica–Salix caprea, Populus tremula+Abies sibirica–Aconitum septentrionale, Abies sibirica+Populus tremulaAegopodium podagraria+Filipendula ulmaria, Abies sibirica+Populus tremula–...

  6. Quantitative relationships between vegetation and several pollen taxa in surface soil from North China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    According to the vegetation investigation and pollen analysis of surface samples sampled along a precipitation gradient of the Northeast China Transect (NECT), several pollen taxa, including Pinus, Betula, Quercus, Tilia, Acer, Ulmus, Artemisia, Chenopodiaceae, Gramineae and Cyperaceae, were chosen to make the regression and correlation analyses. The results indicated that there exists a close relationship between vegetation and pollen taxa in surface samples. The regression parameters for ten taxa in the forests in the eastern part of NECT were different from those in the steppes in the western part. Pinus, Betula, Artemisia and Chenopodiaceae, which have large slope and y-intercept terms, were over-representative taxa. Acer, Gramineae and Cyperaceae, which have small slope and y-intercept terms, were under-representative taxa. Quercus, Tilia and Ulmus whose slope terms have negative correlation with y-intercept terms were equi-representative taxa. The pollen taxa with large slope or large y-intercept terms have small variability coefficients, implying that the slope and y-intercept terms for these pollen taxa are of high accuracy in the estimation of plant abundance from pollen frequencies.

  7. 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.

  8. Hydrogen Apparent Fractionation between Precipitation and Leaf Wax n-Alkanes from Conifers and Deciduous Angiosperms along a Longitudinal Transect in Eurasia

    Science.gov (United States)

    Pedentchouk, Nikolai; Fisher, Katherine; Wagner, Thomas

    2010-05-01

    D/H composition of individual organic compounds derived from leaf wax may provide a wealth of information regarding plant-water relations in studies of plant ecology and climate change. Extracting that information from the organic D/H signal requires a thorough understanding of hydrogen isotope fractionation between environmental water and organic compounds. The purpose of this project is to investigate the importance of plant types and local climatic conditions on hydrogen apparent fractionation in higher terrestrial plants. We determined D/H composition of n-alkanes derived from leaf wax extracted from several extant plants representing common evergreen and deciduous conifer (Pinus and Larix) and deciduous angiosperm (Betula, Salix, and Sorbus) genera along a longitudinal transect from the UK to central Siberia at 10 different locations. These data were used to calculate the apparent fractionation factor (epsilon) between source water, estimated using the Online Isotopes in Precipitation Calculator, and n-alkanes. Our initial results show the following. First, we found large differences in the epsilon values among different genera at each location, e.g. Betula -63‰ vs. Salix -115‰ in Norwich, UK, and Betula -86‰ vs. Salix -146‰ in Novosibirsk, Russia. Assuming the plants at individual locations utilized soil water of very similar deltaD values, variations in the epsilon values are likely to be explained by differences in plant physiology and biochemistry. Second, we identified extensive shifts in the epsilon values in individual species along the transect from the UK to central Siberia, e.g. Betula -63‰ in Norwich vs. -104‰ in Zotino, Krasnoyarsk Krai, central Siberia and Salix -115‰ in Norwich vs. -164‰ in Sodankyla, Finland. With the exception of Sorbus, there is a positive relationship between the MAT (mean annual temperature) and epsilon values at locations above 2 °C MAT, suggesting a possible climatic effect on isotopic fractionation

  9. 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

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

    Directory of Open Access Journals (Sweden)

    Gilissen Ludovicus JWJ

    2006-07-01

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

  11. High-resolution study of Late Glacial and Early Holocene vegetation and tree line changes in the Southern Carpathian Mountains

    Science.gov (United States)

    Magyari, E.; Jakab, G.; Braun, M.; Buczkó, K.; Bálint, M.

    2009-04-01

    The Retezat Massif of the S Carpathian Mountains abounds in glacial lakes, mainly above 1900 m a.s.l., just above the present day tree limit formed by Picea abies and Pinus cembra in the northern slopes. For the reconstruction of Late Glacial and Early Holocene vegetation and tree line changes in this mountain, two lakes were selected: Taul dintre Brazi (1740 m a.s.l.) and Lake Gales (1990 m a.s.l.). Sediments obtained from these lakes extend back to the Late Glacial, and so provide us an exceptional opportunity to study 1) when trees were first established locally around the lower lake following glacial retreat and 2) what tree and shrub species were present and replaced each other in the Late Glacial and early postglacial forests in response to the high-amplitude climatic fluctuation, and in case of the Early Holocene, the high-amplitude climatic amelioration. Pollen, conifer stomata and plant macrofossils were studied from both lake sediments at approximately 100 years resolution. Sediment chronologies were based on multiple AMS radiocarbon dates. Preliminary results from this study show that Pinus mugo, Pinus cembra, Picea abies and Betula nana appeared very early during the lateglacial interstadial, ca. 14,500 cal yr BP followed by Larix decidua around 14,200 cal yr BP. Pinus cembra gained dominance in the Latglacial interstadial forest and survived locally during the Younger Dryas reversal unlike Picea abies. Another important result was the reconstruction of the Early Holocene forest composition around the lower lake that proved much more species rich than the present-day forest; Picea abies grew together with Larix decidua, Pinus mugo, Pinus cembra, Alnus viridis, Juniperus, Betula nana and Betula pubescens during the Early Holocene, furthermore the stomatal record suggested that conifer species were evenly distributed around the lake. In light of our data, the position of the Early Holocene tree line reached 1990 m a.s.l. by ca. 10,700 cal yr BP (i

  12. 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.

  13. 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....... 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....... This was caused partly by increased dominance of EM plants and partly by stimulation of EM mycelial growth. •  We conclude that cycling of carbon and nitrogen through EM fungi will increase when strongly nutrient-limited arctic ecosystems are exposed to a warmer and more nutrient-rich environment. This has...

  14. 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.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    Leena Hamberg

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

  17. 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.

  18. 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.

  19. Long-term forest dynamics at Gribskov, eastern Denmark with early-Holocene evidence for thermophilous broadleaved tree species

    DEFF Research Database (Denmark)

    Overballe-Petersen, Mette V; Nielsen, Anne Birgitte; Hannon, Gina E.

    2012-01-01

    We report on a full-Holocene pollen, charcoal and macrofossil record from a small forest hollow in Gribskov, eastern Denmark. The Fagus sylvatica pollen record suggests the establishment of a small Fagus population at Gribskov in the early Holocene together with early establishment of other...... thermophilous broadleaved trees, including Quercus sp., Tilia sp. and Ulmus sp. The macrofossils contribute to the vegetation reconstruction with evidence for local presence of species with low pollen productivity or easily degraded pollen types such as Populus. The charcoal record shows frequent burning during...... two periods of the early Holocene and from c. 3000 cal. BP to present. The early-Holocene part of the record indicates a highly disturbed forest ecosystem with frequent fires and abundant macrofossils of particularly Betula sp. and Populus sp. The sediment stratigraphy and age–depth relationships give...

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

    Science.gov (United States)

    Kalny, Piotr; Fijałek, Zbigniew; Daszczuk, Anna; Ostapczuk, Peter

    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).

  1. 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)

  2. 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.

  3. 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.

  4. 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.

  5. 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...

  6. Sex differences in cognition are stable over a 10-year period in adulthood and old age.

    Science.gov (United States)

    de Frias, Cindy M; Nilsson, Lars-Göran; Herlitz, Agneta

    2006-01-01

    Sex differences in declarative memory and visuospatial ability are robust in cross-sectional studies. The present longitudinal study examined whether sex differences in cognition were present over a 10-year period, and whether age modified the magnitude of sex differences. Tests assessing episodic and semantic memory, and visuospatial ability were administered to 625 nondemented adults (initially aged 35-80 years), participating in the population-based Betula study at two follow-up occasions. There was stability of sex differences across five age groups and over a 10-year period. Women performed at a higher level than men on episodic recall, face and verbal recognition, and semantic fluency, whereas men performed better than women on a task-assessing, visuospatial ability. Sex differences in cognitive functions are stable over a 10-year period and from 35 to 90 years of age.

  7. Contributions on the diagnosis of fluorine damage. I. Fluorine damage in indicator plants in the wild flora

    Energy Technology Data Exchange (ETDEWEB)

    Borsdorf, W.

    1960-01-01

    In an area of Central Germany affected by gaseous waste containing fluorine, the wild flora and some cultivated plants were investigated as to their suitability as indicators of fluorine pollution. As a result of three years of observation a list of 59 species is presented, four susceptibility groups being distinguished on the basis of the macroscopic symptoms of the damage (necrosis on the leaf tips and margins, less frequently in the zones between the ribs). Vitis vinifera L., Carpinus betula L., Iris germanica L., Arrenatherum clatius (L.) J.u.C. Presl and Dactylis glomenata L. proved to be extremely sensitive. The intensity of the symptoms is influenced, among other things, by a number of environmental factors (topographic features, predominant direction of winds, precipitation and degree of afforestation). 6 references.

  8. [Vegetation and its relation with climate conditions near the timberline of Beitai, the Xiaowutai Mts., northern China].

    Science.gov (United States)

    Yu, Pengtao; Liu, Hongyan; Cui, Haiting

    2002-05-01

    On the basis of field investigations, the timberline range of Beitai, the Xiaowutai Mountains was carved up, and the changes in the makeup and diversity of plants with the altitude were discussed. The results showed that the timberline with gradual changes in the northern slope of Beitai ranged from 2620-2800 m. In timberline, herbaceous plants were rich, and the diversity was higher than that in coniferous forest and sub-alpine meadow zones. The turnover rates of species were gradually hoisting from the centre of timberline to sub-alpine meadow and forest zones, and highest at the edge of timberline. Betula, Picea meyreri and Larix principis-ruprechtii species were the ecological indicator for research on environmental changes. Climate indication significance of these arbor species distributed in and near the timberline was also discussed.

  9. 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

  10. Limiting factors for vegetation development during the early late glacial in Denmark

    DEFF Research Database (Denmark)

    Mortensen, Morten Fischer; Odgaard, Bent Vad; Jessen, Cathrine

    .g. climate change, soil erosion or soil development. In an attempt to identify the most important factors determining the temporal variation of the pollen record at Slotseng, redundancy analysis (RDA) was applied to subsets of pollen data representing a moving window of 20 samples at a time (1-20, 2-21, 3...... to climate change suggests that other factors limited vegetational development. These factors included soil instability, aridity and low soil nitrogen.. This study highlights the multitude of climatic, physical, chemical and biological interactions important for the formation of pollen records of late...... periods at Slotseng was dominated by Betula nana and Dryas octopetala and associated with many herbs of open habitats. Late-glacial pollen records are frequently interpreted only in the context of climate change. However, the forcing mechanisms of vegetational change may shift over time between e...

  11. 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.

  12. Modeling the Current and Future Distribution of Treeline Species in the Nepal Himalaya

    Science.gov (United States)

    Chhetri, P. K.; Cairns, D. M.

    2015-12-01

    Knowledge of the current distribution of treeline species is important for predicting their future distribution in the landscape. Many studies have indicated that treeline will advance with climate change. Treeline advance will result in a loss of alpine biodiversity because the advancing treeline will fragment alpine ecosystems. A species distribution modeling approach using predicted climate data can increase our understanding of how treeline species will expand their range in the future. We used the Maxent model to predict the current and future distributions of three dominant treeline species, Abies spectabilis, Betula utilis, and Pinus wallichiana, of the Nepal Himalaya. The Maxent model predicted that the distribution of treeline species will change significantly under future climate change scenarios. The range of these treeline species will expand northward or upslope in response to future climate change. The model also indicated that temperature-related climatic variables are the most important determinants of the distribution of treeline species.

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

    Science.gov (United States)

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

    2004-09-01

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

  14. Plant species differences in particulate matter accumulation on leaf surfaces.

    Science.gov (United States)

    Sæbø, A; Popek, R; Nawrot, B; Hanslin, H M; Gawronska, H; Gawronski, S W

    2012-06-15

    Particulate matter (PM) accumulation on leaves of 22 trees and 25 shrubs was examined in test fields in Norway and Poland. Leaf PM in different particle size fractions (PM(10), PM(2.5), PM(0.2)) differed among the species, by 10- to 15-folds at both test sites. Pinus mugo and Pinus sylvestris, Taxus media and Taxus baccata, Stephanandra incisa and Betula pendula were efficient species in capturing PM. Less efficient species were Acer platanoides, Prunus avium and Tilia cordata. Differences among species within the same genus were also observed. Important traits for PM accumulation were leaf properties such as hair and wax cover. The ranking presented in terms of capturing PM can be used to select species for air pollution removal in urban areas. Efficient plant species and planting designs that can shield vulnerable areas in urban settings from polluting traffic etc. can be used to decrease human exposure to anthropogenic pollutants.

  15. Reproductive strategies of Caltha palustris L. under various living conditions

    Directory of Open Access Journals (Sweden)

    Cezary Werpachowski

    2014-01-01

    Full Text Available Reproductive effort and strategies of Caltha palustris were compared for four phytocoeno­ses located in the southern Biebrza basin: sedge reedswamp (Caricetum gracilis, sedge-moss community (Caricetum limoso-diandrae, willow-birch brushwood (Salix cinerea-Betula pubescens, and alder-bog forest (Carici elongatae-Alnetum, The individuals of analysed populations were found to differ with respect to their biomass allocation to generative and vegetative reproduction. Three types of reproductive strategies were distinguished: generative (G, vegetative (V and intermediate (G/V. The individuals growing in the alder-bog forest had the highest reproductive effort (V strategy, while those from sedge reedswamp - the lowest (G strategy.

  16. Deconstruction of Nordic hardwood in switchable ionic liquids and acylation of the dissolved cellulose.

    Science.gov (United States)

    Eta, Valerie; Mikkola, Jyri-Pekka

    2016-01-20

    Nordic hardwood (Betula pendula) was fractionated in a batch autoclave equipped with a custom-made SpinChem(®) rotating bed reactor, at 120 °C using CO2 and CS2-based switchable ionic liquids systems. Analyses of the non-dissolved wood after treatment showed that 64 wt% of hemicelluloses and 70 wt% of lignin were removed from the native wood. Long processing periods or successive short-time treatments using fresh SILs further decreased the amount of hemicelluloses and lignin in the non-dissolved fraction to 12 and 15 wt%, respectively. The cellulose-rich fraction was partially dissolved in an organic superbase and an ionic liquid system for further derivatization. Homogeneous acylation of the dissolved cellulose in the presence or absence of catalyst resulted in cellulose acetates with variable degree of substitution (DS), depending on the treatment conditions. By varying the reaction conditions, the cellulose acetate with the desired DS could be obtained under mild conditions.

  17. 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.

  18. Tundra in the rain: differential vegetation responses to three years of experimentally doubled summer precipitation in Siberian shrub and Swedish bog tundra.

    Science.gov (United States)

    Keuper, Frida; Parmentier, Frans-Jan W; Blok, Daan; van Bodegom, Peter M; Dorrepaal, Ellen; van Hal, Jurgen R; van Logtestijn, Richard S P; Aerts, Rien

    2012-01-01

    Precipitation amounts and patterns at high latitude sites have been predicted to change as a result of global climatic changes. We addressed vegetation responses to three years of experimentally increased summer precipitation in two previously unaddressed tundra types: Betula nana-dominated shrub tundra (northeast Siberia) and a dry Sphagnum fuscum-dominated bog (northern Sweden). Positive responses to approximately doubled ambient precipitation (an increase of 200 mm year(-1)) were observed at the Siberian site, for B. nana (30 % larger length increments), Salix pulchra (leaf size and length increments) and Arctagrostis latifolia (leaf size and specific leaf area), but none were observed at the Swedish site. Total biomass production did not increase at either of the study sites. This study corroborates studies in other tundra vegetation types and shows that despite regional differences at the plant level, total tundra plant productivity is, at least at the short or medium term, largely irresponsive to experimentally increased summer precipitation.

  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. PURIFICATION OF HARDWOOD-DERIVED AUTOHYDROLYSATES

    Directory of Open Access Journals (Sweden)

    Joni Tapani Lehto,

    2012-02-01

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

  1. MECHANICAL PROPERTIES ANALYSIS AND RELIABILITY ASSESSMENT OF LAMINATED VENEER LUMBER (LVL HAVING DIFFERENT PATTERNS OF ASSEMBLY

    Directory of Open Access Journals (Sweden)

    Bing Xue,

    2012-02-01

    Full Text Available Laminated Veneer Lumber (LVL panels made from poplar (Populus ussuriensis Kom. and birch (Betula platyphylla Suk. veneers were tested for mechanical properties. The effects of the assembly pattern on the modulus of elasticity (MOE and modulus of rupture (MOR of the LVL with vertical load testing were investigated. Three analytical methods were used: composite material mechanics, computer simulation, and static testing. The reliability of the different LVL assembly patterns was assessed using the method of Monte-Carlo. The results showed that the theoretical and ANSYS analysis results of the LVL MOE and MOR were very close to those of the static test results, and the largest proportional error was not greater than 5%. The veneer amount was the same, but the strength and reliability of the LVL made of birch veneers on the top and bottom was much more than the LVL made of poplar veneers. Good assembly patterns can improve the utility value of wood.

  2. 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.

  3. 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.

  4. 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.

  5. A Primary Study on Altitudinal Pattern, Type of of Picea brachytyla formation in Baishuijiang Nature Reserve%白水江自然保护区麦吊云杉群落类型与垂直格局初步分析

    Institute of Scientific and Technical Information of China (English)

    王建宏; 许闰; 吴俊成; 尹峰

    2006-01-01

    麦吊云杉(Picea brachytyla)为我国二级重点保护植物,也是甘肃白水江国家级自然保护区针阔混交林带(2 100~2 900 m)主要的建群种之一.以第3次大熊猫调查植被数据为基础,以树种重要值为指标,分析了白水江保护区麦吊云杉群落的结构特征.结果表明:该保护区麦吊云杉群落按乔木重要值的大小可划分为10个亚群系,其中与糙皮桦(Betula utilis)和红桦(Betula albo-sinensis)形成的混交林分布最广;麦吊云杉的主要伴生树种为糙皮桦和红桦,其次为铁杉(Tsuga chinensis)、岷江冷杉(Abies chensiensis)、五裂槭(Acer oliverianum)、泡花树(Meliosma dilleniifolia)、华山松(Pinus armandi)等;麦吊云杉群落从低海拔向高海拔的递变规律是由与温性针阔叶树种华山松、铁杉、糙皮桦、红桦等组成的亚群系向与寒温性针叶树冷杉等形成亚群系递变.

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

    Directory of Open Access Journals (Sweden)

    Amon, Leeli

    2010-06-01

    Full Text Available Reinvestigation of the late glacial Solova (Remmeski basin, based on plant macro­fossil and diatom record, AMS 14C chronology and sediment composition (loss-on-ignition and magnetic susceptibility data, provided information on vegetation history and palaeoenvironmental and palaeoclimatic changes since the time of the deglaciation of the area around 14 000 cal yr BP. The chronology of the sequence is based on seven AMS dates on terrestrial macrofossils, providing evidence of rapid sedimentation in between 14 000 and 13 500 cal yr BP. Loss-on-ignition data show a clear short-lived warming episode centred to 13 800 cal yr BP, tentatively correlated with the GI-1c warming of the event stratigraphy of the Last Termination in the North Atlantic region, which suggests that at least parts of the Haanja Heights were ice-free by 14 000 cal yr BP. Macrofossil evidence indicates Betula nana–Dryas octopetala-dominated open tundra communities with Saxifraga on dry ground, and Carex sp. and Juncus on wet ground at that time. The first evidence of the postglacial presence of tree birch (Betula pendula in Estonia is dated back to 13 500 cal yr BP. However, conifer remains were not found in the late glacial sediment sequence of Solova Bog. The late-Allerød (GI-1a organic deposits, which are quite typical of other parts of Estonia and indicate general warming, are missing at Solova, most probably due to a hiatus in sedimentation in this very small and shallow upland basin.

  7. 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

    Directory of Open Access Journals (Sweden)

    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.

  8. Younger Dryas To Mid-Holocene Environmental History Of The Lowlands Of NW Transylvania, Romania

    Science.gov (United States)

    Feurdean, A.; Mosbrugger, V.; Onac, B. P.; Polyak, V.; Veres, D.

    2007-12-01

    Pollen, micro-charcoal and total carbon analyses on sediments from the Turbuta profile located in the Transylvanian Basin (NW Romania) reveal information on previously unknown Younger Dryas to mid-Holocene environmental changes. The chronostratigraphy relies on AMS 14C measurements on organic matter and U/Th TIMS datings of snail shells. Results indicate the presence of Pinus and Betula open woodlands with small populations of Picea, Ulmus, Alnus and Salix before 12,000 cal yr BP, correlates well with the environmental developments expected for Younger Dryas stadial. A fairly abrupt replacement of Pinus and Betula by Ulmus dominated woodlands at ca. 11,900 cal. yr BP, likely represents competition effects of vegetation driven by climate warming at the onset of the Holocene. By 11,000 cal yr BP, the woodlands were increasingly diverse and dense with the expansion of Quercus, Fraxinus and Tilia, the establishment of Corylus, and the decline of upland herbaceous and shrubs taxa. The marked expansion of Quercus accompanied by Tilia between 10,500 and 8,000 cal yr BP could be the result of low effective moisture associated with both low elevation of the site and with regional change towards a drier climate. At 10,000 cal. yr BP Corylus spread across the region, and by 8,000 cal yr BP it replaced Quercus as a dominant forest constituent, with only little representation of Picea abies. Carpinus became established around 5,500 cal yr BP, but it was only a minor constituent in local woodlands until ca. 5,000 cal yr BP. Results from this study also indicate that the woodlands in the lowlands of Turbuta were never closed.

  9. Rapid carbon turnover beneath shrub and tree vegetation is associated with low soil carbon stocks at a subarctic treeline.

    Science.gov (United States)

    Parker, Thomas C; Subke, Jens-Arne; Wookey, Philip A

    2015-05-01

    Climate warming at high northern latitudes has caused substantial increases in plant productivity of tundra vegetation and an expansion of the range of deciduous shrub species. However significant the increase in carbon (C) contained within above-ground shrub biomass, it is modest in comparison with the amount of C stored in the soil in tundra ecosystems. Here, we use a 'space-for-time' approach to test the hypothesis that a shift from lower-productivity tundra heath to higher-productivity deciduous shrub vegetation in the sub-Arctic may lead to a loss of soil C that out-weighs the increase in above-ground shrub biomass. We further hypothesize that a shift from ericoid to ectomycorrhizal systems coincident with this vegetation change provides a mechanism for the loss of soil C. We sampled soil C stocks, soil surface CO2 flux rates and fungal growth rates along replicated natural transitions from birch forest (Betula pubescens), through deciduous shrub tundra (Betula nana) to tundra heaths (Empetrum nigrum) near Abisko, Swedish Lapland. We demonstrate that organic horizon soil organic C (SOCorg ) is significantly lower at shrub (2.98 ± 0.48 kg m(-2) ) and forest (2.04 ± 0.25 kg m(-2) ) plots than at heath plots (7.03 ± 0.79 kg m(-2) ). Shrub vegetation had the highest respiration rates, suggesting that despite higher rates of C assimilation, C turnover was also very high and less C is sequestered in the ecosystem. Growth rates of fungal hyphae increased across the transition from heath to shrub, suggesting that the action of ectomycorrhizal symbionts in the scavenging of organically bound nutrients is an important pathway by which soil C is made available to microbial degradation. The expansion of deciduous shrubs onto potentially vulnerable arctic soils with large stores of C could therefore represent a significant positive feedback to the climate system.

  10. HPLC identification and determination of myricetin, quercetin, kaempferol and total flavonoids in herbal drugs

    Directory of Open Access Journals (Sweden)

    Svetlana Kulevanova

    2003-05-01

    Full Text Available A new and rapid HPLC method for identification and determination of myricetin, quercetin, kaempferol and total flavonoids in ten herbal drugs of Macedonian origin is presented. Preparation of samples (Uvae ursi folim, Pruni spinosae flos, Sambuci flos, Betulae folim, Primulae flos, Herniariae herba, Centaurii herba, Tiliae flos, Robiniae pseudoacaciae flos, Bursae pastoris herba included hydrolysis of glycosides and extraction of total aglycones with ethyl acetate. HPLC analysis with UV-diode array detection was carried out on RP C18 column, using 5% acetic acid and acetonitrile in agradient elution mode and column temperature of 30 o C. The monitoring of the elution is performed in the whole UV-range and the acquisition of data for quantitative analysis at 367 nm. Screening of the extracts showed presence of quercetin in nine, kaempferol in seven and myricetin in only one sample. The quantitative analysis showed that the content of quercetin ranged from 0.026-0.506 % (m/m, while for kaempferol it was from traces to 1.246 %. Uvaeursi folium and Pruni spinosae flos were rich in content of quercetin (0.482 % and 0.506 %, respectively, while Pruni spinosae flos and Robiniae pseudoaccaciae flos contained the highest amounts of kaempferol (1.246 % and 0.892 %, respectively. Myricetin was identified and determined only in Betulae folium (0.102 %. The content of total flavonoids in the investigated samples expressed in terms of quercetin ranged from 0.040 to 1.680 %. The proposed HPLC method is convenient for use in routine analysis of myricetin, quercetin and kaempferol, as well as for estimation of total flavonoids content in herbal drugs.

  11. 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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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

  13. 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).

  14. Spatial Pattern for Fraxinus mandshurica Population in Second Growth Forest of Maoershan Mountains%帽儿山地区天然次生林中水曲柳种群格局分析

    Institute of Scientific and Technical Information of China (English)

    吴文娟; 王庆成; 许丽娟

    2013-01-01

    采用点格局分析法研究帽儿山地区天然次生林中水曲柳( Fraxinus mandshurica)不同龄级的种群空间分布格局及水曲柳与五角槭( Acer mono)、春榆( Ulmus propinqua)和白桦(Betula platyphylla )种群的空间关联性。结果表明:水曲柳龄级I林木个体在1~50 m尺度上呈现聚集分布;龄级II与龄级III的聚集程度较龄级I缓和;水曲柳龄级III与龄级I、龄级II林木个体在所有尺度上都表现为显著负相关或有负相关趋势。林分内主要树种种群有不同的空间格局分布,其中水曲柳在小尺度(10~22 m)上表现聚集分布,在大尺度则呈随机分布;五角槭、春榆和白桦在各个尺度下均呈聚集分布。种间关联性分析表明:水曲柳与五角槭、白桦和春榆在空间关联上都呈现正相关或有正相关趋势。水曲柳种群与群落内其它优势树种形成的斑块在群落中镶嵌分布,具有较高的群落稳定性;但水曲柳幼树在大树聚集的斑块不易存活,影响了水曲柳种群发展。%We analyzed spatial pattern distributions for different age classes of Fraxinus mandshurica and spatial associations be-tween Fraxinus mandshurica and other dominant species ( Acer mono, Ulmus propinqua and Betula platyphylla) for second growth forest in Maoershan Mountains .Individuals in age class I of Fraxinus mandshurica show clumped distribution at scales from 1 m to 50 m.Individuals of age class II and age class III show weaker clumped distribution than those of age class I.Age class III shows negative correlation with age class I at most scales, and it also exhibits negative association with age class II.Fraxinus mandshurica population shows clumped distribution at small-scale (10-22 m) and random dis-tribution at large-scale (23-50 m).The spatial pattern distributions of Acer mono, Ulmus propinqua and Betula platyphylla show clumped distribution.With the association analysis, they have

  15. Interactions between climate and vegetation during the Lateglacial period as recorded by lake and mire sediment archives in Northern Italy and Southern Switzerland

    Science.gov (United States)

    Vescovi, Elisa; Ravazzi, Cesare; Arpenti, Enrico; Finsinger, Walter; Pini, Roberta; Valsecchi, Verushka; Wick, Lucia; Ammann, Brigitta; Tinner, Willy

    2007-06-01

    We reconstruct the vegetational history of the southern side of the Alps at 18,000-10,000 cal yr BP using previous and new AMS-dated stratigraphic records of pollen, stomata, and macrofossils. To address potential effects of climatic change on vegetation, we compare our results with independent paleoclimatic series (e.g. isotope and chironomid records from the Alps and the Alpine forelands). The period before 16,000 cal yr BP is documented only at the lowland sites. The previous studies used for comparison with our new Palughetto record, however, shows that Alpine deglaciation must have started before 18,000-17,500 cal yr BP south of the Alps and that deglaciated sites were colonized by open woods and shrublands ( Juniperus, tree Betula, Larix, Pinus cembra) at ca 17,500 cal yr BP. The vegetational history of a new site (Palughetto, 1040 m a.s.l.) is consistent with that of previous investigations in the study region. Our results show three conspicuous vegetational shifts delimited by statistically significant pollen zones, at ca 14,800-14,400, 13,300-12,800 and 11,600-11,200 cal yr BP. At sites situated above 1000 m a.s.l. (e.g. Palughetto, Pian di Gembro) forests expanded in alpine environments at ca 14,500 cal yr BP (onset of Bølling period, GI-1 in the Greenland ice record). At the same time, rather closed treeline communities of the lowlands were replaced by dense stands of Pinus sylvestris and Betula. These early forests and shrublands consisted of Larix, P. cembra, Juniperus, P. sylvestris, Pinus mugo, and Betula, and had become established at ca 16,000 cal yr BP, probably in response to a temperature increase. If combined with other records from the Southern Alps, our data suggest that treeline ascended by ca 800-1000 m in a few centuries at most, probably as a consequence of climatic warming at the beginning of the Bølling period. At 13,100-12,800 cal yr BP the onset of a long-lasting decline of P. sylvestris was accompanied by the expansion of Quercus

  16. 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

  17. 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

  18. 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

  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. 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

  1. 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.

  2. Recent pollen spectra and zonal vegetation in the western USSR

    Science.gov (United States)

    Peterson, G. M.

    The relationship of modern pollen spectra to present-day vegetation is critical to the reconstruction of vegetation and climate from fossil pollen spectra. This study uses isopoll maps to illustrate the pollen-vegetation relationships in the Soviet Union west of 100°E and presents descriptive statistics for 544 modern samples of arboreal pollen and for 370 samples of herb pollen obtained from the Soviet palynological literature. Data are assembled from this large geographic region and presented in a standardized form on a scale which can be used to relate quantitative pollen data to zonal vegetation and climatic variables and to make comparisons with other regions. In order to show the relationship between pollen types and major ecotones in forested and non-forested areas, the pollen data are presented as percentages of a sum including both arboreal and non-arboreal pollen. Major pollen types which attain values of 10% or more in at least one vegetation zone include Betula (birch), Cyperaceae (sedges), Picea (spruce), Pinus (total pine), Pinus sibirica, Ericaceae (heath family), Gramineae (grasses), Artemisia (sage), and Chenopodiaceae (i.e., saltbush, Russian thistle, pigweed family). Samples from the tundra and forest-tundra have high values of Ericaceae (heath family), birch, alder, and sedge pollen. In the boreal forest, pine, spruce, and birch pollen predominate. In the mixed and deciduous forests, Tilia (linden), Quercus (oak), Ulmus (elm), and Corylus (hazel) pollen attain maximum values. In the forest-steppe and steppe zones, arboreal pollen decreases in importance and is replaced by non-arboreal pollen types. Pollen of Artemisia and Chenopodiaceae predominates in the semi-desert zones. In spite of variation in the pollen spectra arising from the use of different sediment types (soil, peat, and river sediments), and human disturbance of vegetation, the pollen spectra are clearly related to zonal vegetation. Pollen spectra from the western USSR show

  3. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-12-01

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

  5. 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

  6. Late Pleniglacial vegetation in eastern-central Europe: are there modern analogues in Siberia?

    Science.gov (United States)

    Magyari, Enikő Katalin; Kuneš, Petr; Jakab, Gusztáv; Sümegi, Pál; Pelánková, Barbora; Schäbitz, Frank; Braun, Mihály; Chytrý, Milan

    2014-07-01

    To characterize Late Pleniglacial (LPG: 26.5-15 ka cal BP) and particularly Last Glacial Maximum (LGM: 21 ± 2 ka cal BP) vegetation and climate, fossil pollen assemblages are often compared with modern pollen assemblages. Given the non-analogue climate of the LPG, a key question is how glacial pollen assemblages and thereby vegetation compare with modern vegetation. In this paper we present three LPG pollen records from the Carpathian Basin and the adjoining Carpathian Mountains to address this question and provide a concise compositional characterization of the LPG vegetation. Fossil pollen assemblages were compared with surface pollen spectra from the Altai-Sayan Mountains in southern Siberia. This area shows many similarities with the LPG vegetation of eastern-central Europe, and has long been considered as its best modern analogue. Ordination and analogue matching were used to characterize vegetation composition and find the best analogues. Our results show that few LPG pollen assemblages have statistically significant analogues in southern Siberia. When analogue pairings occur they suggest the predominance of wet and mesic grasslands and dry steppe in the studied region. Wooded vegetation types (continental and suboceanic hemiboreal forest, continental taiga) appear as significant analogues only in a few cases during the LGM and more frequently after 16 ka cal BP. These results suggest that the LPG landscape of the Carpathian Basin was dominated by dry steppe that occurred outside the river floodplains, while wet and mesic grasslands occurred in the floodplains and on other sites influenced by ground water. Woody vegetation mainly occurred in river valleys, on wet north-facing hillsides, and scattered trees were likely also present on the loess plateaus. The dominant woody species were Larix, Pinus sylvestris, Pinus mugo, Pinus cembra, Picea abies, Betula pendula/pubescens, Betula nana, Juniperus, Hippophaë rhamnoides, Populus, Salix and Alnus. The pollen

  7. 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

  8. 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

  9. 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

  10. Quantitative relationship between pollen and vegetation in northern China

    Institute of Scientific and Technical Information of China (English)

    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 domi- nant 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 vegeta- tion 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%, Ulmus or Populus trees should exist. For shrubby pollen types, the correlation be- tween Vitex pollen percentages and vegetation cover is the highest, then is Corylus

  11. 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

  12. 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

  13. 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

  14. Properties of tree and grass pollen allergens: reinvestigation of the linkage between solubility and allergenicity.

    Science.gov (United States)

    Vrtala, S; Grote, M; Duchêne, M; van Ree, R; Kraft, D; Scheiner, O; Valenta, R

    1993-01-01

    In this study we reinvestigated the kinetics of allergen release from birch pollen (Betula verrucosa) and timothy grass pollen (Phleum pratense) using different protein extraction procedures, immunoblotting with specific antibodies and immune electron microscopy. Pollen allergens such as the major birch pollen allergen, Bet v I, the major timothy grass pollen allergens, Phl p I and Phl p V, group-II/III allergens from timothy grass and profilins were released rapidly and in large amounts from hydrated pollen. Within a few minutes pollen allergens could be detected in aqueous supernatants prepared from birch and grass pollen with serum IgE or specific antibodies. In parallel the allergen content in the pollen pellet fractions decreased. A nonallergenic protein such as heat shock protein 70 can be extracted in sufficient amounts only with harsh extraction procedures. Immune electron microscopy of dry and rehydrated birch pollens showed that after short hydration, the major birch pollen allergen, Bet v I, migrated into the exine and to the surface of intact pollen grains, whereas profilin, against which a lower percentage of patients is sensitized, was retained in the pollen grain. Comparing the amino acid composition and hydrophilicity of the tested allergens with a nonallergenic protein such as heat shock protein 70, no significant difference was noted. In agreement with earlier observations we conclude that the allergenic properties of proteins are rather linked to the amount and speed of solubility from airborne particles than to intrinsic properties.

  15. The sedimentary sequence from the Lake Ķūži outcrop, central Latvia: implications for late glacial stratigraphy

    Directory of Open Access Journals (Sweden)

    Tiiu Koff

    2011-06-01

    Full Text Available Sediment samples from an outcrop in the near-shore area of Lake Ķūži (Vidzeme Heights, Central Latvia were investigated using palaeobotanical (pollen and macrofossil analysis and lithological (grain-size analysis methods and accelerator mass spectrometry 14C dating. A dark, organic-rich sediment layer was found below 1.7 m of sandy layers approximately 30 cm above the present lake level. Radiocarbon dating of a wood sample from the lowermost layer (11 050 ± 60 14C BP, 13 107–12 721 cal BP shows that the layer is of late glacial age. The composition of the pollen spectra is characterized by Betula nana, Cyperaceae pollen and spores of Equisetum, confirming that the lowermost sediments were formed during the late glacial. Fossils of obligate aquatic organisms in the upper layer, which include oospores of Characeae and seeds of Potamogeton, indicate an open water environment. Pollen of Myriophyllum and Potamogeton and non-pollen palynomorphs, such as algal Botryococcus and Pediastrum cf. boryanum, confirm this conclusion. The pollen assemblage from the greyish loam layer following this lacustrine phase shows a pattern characteristic of the Younger Dryas vegetation before the start of the real expansion of birch forests at the beginning of the Holocene.

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

    Directory of Open Access Journals (Sweden)

    Chiang Vincent L

    2009-09-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  18. The importance of the stationary and individual pollen monitoring for the diagnostic of pollen allergy

    Directory of Open Access Journals (Sweden)

    Dorota Myszkowska

    2012-12-01

    Full Text Available The aim of the study was to evaluate pollen seasons of selected taxa with particular reference to allergic taxa such as birch (Betula sp., grasses (Poaceae, mugwort (Artemisia sp. in Cracow in 2003 and 2004 (project number 3 PO5D 034 24 funded by the State Committee for Scientific Research. Pollen concentrations obtained using the stationary Burkard trap and personal Partrap FA 52 were compared. The volumetric method was used in the study. Average daily concentrations (pollen grains × m-3 were obtained by counting pollen grains every hour along 4 longitudinal transects and applying an appropriate conversion factor. Duration of the pollen season was determined using the 95% method. Variations in annual totals of pollen grains (birch and mugwort, in start dates (especially for grasses and in the season duration (birch and grasses were found. The comparison of pollen concentrations obtained using the stationary and personal traps at the same place showed non statistically significant correlation for all the studied taxa and statistically significant correlations for birch, mugwort and grasses (Spearman rank correlation. However, the statistically significant differences between the concentrations obtained using Burkard and Partrap carried by patients (Wilcoxon's test were noted. Very low concentrations of pollen grains measured indoor (work, flats and the influence of the local plants growing in separate place (courtyard of the Allergology Department on the pollen concentration were found.

  19. The likely impact of climate change on the biodiversity of Italian forests

    Directory of Open Access Journals (Sweden)

    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.

  20. Vegetation impact on the thermal regimes of the active layer and near-surface permafrost in the Greater Hinggan Mountains, Northeastern China

    Institute of Scientific and Technical Information of China (English)

    XiaoLi Chang; ShaoPeng Yu; HuiJun Jin; YanLin Zhang

    2014-01-01

    The ground temperature and active layer are greatly influenced by vegetation in the Greater Hinggan Mountains in Northeastern China. However, vegetation, as a complex system, is difficult to separate the influence of its different components on the ground thermal regime. In this paper, four vegetation types, including a Larix dahurica-Ledum palustre var. dilatatum-Bryum forest (P1), a L. dahurica-Betula fruticosa forest (P2), a L. dahurica-Carex tato forest (P3) in the China Forest Ecological Research Network Station in Genhe, and a Carex tato swamp (P4) at the permafrost observation site in Yitulihe, have been selected to study and compare their seasonal and annual influence on the ground thermal regime. Results show that the vegetation insulates the ground resulting in a relatively high ground temperature variability in the Carex tato swamp where there are no tree stands and shrubs when compared with three forested vegetation types present in the area. Vegetation thickness, structure, and coverage are the most important factors that determine the insulating prop-erties of the vegetation. In particular, the growth of ground cover, its water-holding capacity and ability to intercept snow exert a significant effect on the degree of insulation of the soil under the same vegetation.

  1. Host associations between fungal root endophytes and boreal trees.

    Science.gov (United States)

    Kernaghan, Gavin; Patriquin, Glenn

    2011-08-01

    Fungal root endophytes colonize root tissue concomitantly with mycorrhizal fungi, but their identities and host preferences are largely unknown. We cultured fungal endophytes from surface-sterilized Cenococcum geophilum ectomycorrhizae of Betula papyrifera, Abies balsamea, and Picea glauca from two boreal sites in eastern Canada. Isolates were initially grouped on the basis of cultural morphology and then identified by internal transcribed spacer ribosomal DNA sequencing or by PCR restriction fragment length polymorphism. Phylogenetic analysis of the sequence data revealed 31 distinct phylotypes among the isolates, comprising mainly members of the ascomycete families Helotiaceae, Dermateaceae, Myxotrichaceae, and Hyaloscyphaceae, although other fungi were also isolated. Multivariate analyses indicate a clear separation among the endophyte communities colonizing each host tree species. Some phylotypes were evenly distributed across the roots of all three host species, some were found preferentially on particular hosts, and others were isolated from single hosts only. The results indicate that fungal root endophytes of boreal trees are not randomly distributed, but instead form relatively distinct assemblages on different host tree species.

  2. 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.

  3. 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.)

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

    Directory of Open Access Journals (Sweden)

    Vyacheslav V Martemyanov

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

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

    Directory of Open Access Journals (Sweden)

    Vadim G. Lebedev

    2017-01-01

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

  6. Rhododenol and raspberry ketone impair the normal proliferation of melanocytes through reactive oxygen species-dependent activation of GADD45.

    Science.gov (United States)

    Kim, Minjeong; Baek, Heung Soo; Lee, Miri; Park, Hyeonji; Shin, Song Seok; Choi, Dal Woong; Lim, Kyung-Min

    2016-04-01

    Rhododenol or rhododendrol (RD, 4-(4-hydroxyphenyl)-2-butanol) occurs naturally in many plants along with raspberry ketone (RK, 4-(4-hydroxyphenyl)-2-butanone), a ketone derivative, which include Nikko maple tree (Acer nikoense) and white birch (Betula platyphylla). De-pigmenting activity of RD was discovered and it was used as a brightening ingredient for the skin whitening cosmetics. Recently, cosmetics containing RD were withdrawn from the market because a number of consumers developed leukoderma, inflammation and erythema on their face, neck and hands. Here, we explored the mechanism underlying the toxicity of RD and RK against melanocytes using B16F10 murine melanoma cells and human primary epidermal melanocytes. Treatment with RD or RK resulted in the decreased cell viability in a dose-dependent manner which appeared from cell growth arrest. Consistently, ROS generation was significantly increased by RD or RK as determined by DCF-enhanced fluorescence. An antioxidant enzyme, glutathione peroxidase was depleted as well. In line with ROS generation, oxidative damages and the arrest of normal cell proliferation, GADD genes (Growth Arrest and DNA Damage) that include GADD45 and GADD153, were significantly up-regulated. Prevention of ROS generation with an anti-oxidant, N-acetylcysteine (NAC) significantly rescued RD and RK-suppressed melanocyte proliferation. Consistently, up-regulation of GADD45 and GADD153 was significantly attenuated by NAC, suggesting that increased ROS and the resultant growth arrest of melanocytes may contribute to RD and RK-induced leukoderma.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Dermocosmetics for dry skin: a new role for botanical extracts.

    Science.gov (United States)

    Casetti, F; Wölfle, U; Gehring, W; Schempp, C M

    2011-01-01

    Dry skin is associated with a disturbed skin barrier and reduced formation of epidermal proteins and lipids. During recent years, skin-barrier-reinforcing properties of some botanical compounds have been described. Searching the PubMed database revealed 9 botanical extracts that specifically improve skin barrier and/or promote keratinocyte differentiation in vivo after topical application. The topical application of Aloe vera (leaf gel), Betula alba (birch bark extract), Helianthus annuus (sunflower oleodistillate), Hypericum perforatum (St. John's wort extract), Lithospermum erythrorhizon (root extract), Piptadenia colubrina (angico-branco extract) and Simarouba amara (bitter wood extract) increased skin hydration, reduced the transepidermal water loss, or promoted keratinocyte differentiation in humans in vivo. The topical application of Rubia cordifolia root extract and rose oil obtained from Rosa spp. flowers stimulated keratinocyte differentiation in mouse models. The underlying mechanisms of these effects are discussed. It is concluded that some botanical compounds display skin-barrier-reinforcing properties that may be used in dermocosmetics for dry skin. However, more investigations on the mode of action and more vehicle-controlled studies are required.

  14. 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.

  15. Predicting onset and duration of airborne allergenic pollen season in the United States

    Science.gov (United States)

    Zhang, Yong; Bielory, Leonard; Cai, Ting; Mi, Zhongyuan; Georgopoulos, Panos

    2015-02-01

    Allergenic pollen is one of the main triggers of Allergic Airway Disease (AAD) affecting 5%-30% of the population in industrialized countries. A modeling framework has been developed using correlation and collinearity analyses, simulated annealing, and stepwise regression based on nationwide observations of airborne pollen counts and climatic factors to predict the onsets and durations of allergenic pollen seasons of representative trees, weeds and grass in the contiguous United States. Main factors considered are monthly, seasonal and annual mean temperatures and accumulative precipitations, latitude, elevation, Growing Degree Day (GDD), Frost Free Day (FFD), Start Date (SD) and Season Length (SL) in the previous year. The estimated mean SD and SL for birch (Betula), oak (Quercus), ragweed (Ambrosia), mugwort (Artemisia) and grass (Poaceae) pollen season in 1994-2010 are mostly within 0-6 days of the corresponding observations for the majority of the National Allergy Bureau (NAB) monitoring stations across the contiguous US. The simulated spatially resolved maps for onset and duration of allergenic pollen season in the contiguous US are consistent with the long term observations.

  16. 秦岭地区15 ka BP以来的植被与环境%The vegetational and environmental history in Qinling Mountain since 15 ka BP

    Institute of Scientific and Technical Information of China (English)

    赵先贵; 肖玲

    2003-01-01

    通过对秦岭海拔2 200 m一山间盆地沼泽沉积剖面的花粉分析和14C年代测定,结合对该区植被与表土花粉的研究,认为秦岭的暗针叶林带15 ka BP以来植被和环境经历了4个发展阶段:(1) 约15 450~6 760 a BP,植被为冷杉(Abies)-云杉(Picea)林,气候寒冷潮湿;(2) 约6 760~2 940 a BP,沉积物中花粉稀少,以冷杉、云杉、桦(Betula)、栎(Quercus)为主,出现了喜暖型植物桤木(Alnus),气候暖湿;(3) 2 940~40 a BP,植被为冷杉林,气候冷湿;(4) 0~40 a BP,植被为桦、栎、榛(Corylus)、桤木、铁杉(Tsuga)和小片状分布的冷杉,松(Pinus)的数量极少,气候向暖干方向发展,这是近期人为活动干扰的结果.

  17. 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.

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

    Science.gov (United States)

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

    2017-01-01

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

  19. Reaction of Leaf Weevil Phyllobius arborator (Coleoptera: Curculionidae) to Manganese Content in Diet.

    Science.gov (United States)

    Martinek, P; Kula, E; Hedbávný, J

    2016-12-27

    Reaction of leaf weevil (Phyllobius arborator (Herbst)) to increased concentration of manganese in diet was investigated in laboratory rearing with controlled temperature, humidity, and light conditions. Food for leaf weevils in rearing (leaves of birch Betula pendula Roth) was contaminated by soaking the leaves in solutions of MnCl24H2O with graded concentration of manganese. Direct influence of food was characterized by the consumed amount of leaves, period of feeding, and weight of P. arborator adults. At the same time, the levels of manganese in unconsumed food, excrement, and bodies of adults were determined.Even very high content of manganese in food did not cause significantly different reaction of P. arborator adults in comparison to individuals in control treatment. No significant difference in the quantity of the consumed food, weight of adults, and duration of their feeding period was found between the treatments within the experiment. The content of manganese found in food, excrement, and adult beetles indicate that P. arborator avoided manganese intoxication through food by both-voiding manganese through the feces and sequestering it at relatively high concentrations in unspecified parts of their body.

  20. Linking belowground and aboveground phenology in two boreal forests in Northeast China.

    Science.gov (United States)

    Du, Enzai; Fang, Jingyun

    2014-11-01

    The functional equilibrium between roots and shoots suggests an intrinsic linkage between belowground and aboveground phenology. However, much less understanding of belowground phenology hinders integrating belowground and aboveground phenology. We measured root respiration (Ra) as a surrogate for root phenology and integrated it with observed leaf phenology and radial growth in a birch (Betula platyphylla)-aspen (Populus davidiana) forest and an adjacent larch (Larix gmelinii) forest in Northeast China. A log-normal model successfully described the seasonal variations of Ra and indicated the initiation, termination and peak date of root phenology. Both root phenology and leaf phenology were highly specific, with a later onset, earlier termination, and shorter period of growing season for the pioneer tree species (birch and aspen) than the dominant tree species (larch). Root phenology showed later initiation, later peak and later termination dates than leaf phenology. An asynchronous correlation of Ra and radial growth was identified with a time lag of approximately 1 month, indicating aprioritization of shoot growth. Furthermore, we found that Ra was strongly correlated with soil temperature and air temperature, while radial growth was only significantly correlated with air temperature, implying a down-regulating effect of temperature. Our results indicate different phenologies between pioneer and dominant species and support a down-regulation hypothesis of plant phenology which can be helpful in understanding forest dynamics in the context of climate change.

  1. [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.

  2. 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.

  3. A Method for In-Situ Measurement of Stem Water Content in Trees and Shrubs Using Time Domain Reflectometry

    Science.gov (United States)

    Clark, J.; Tape, K. D.; Young, J.

    2015-12-01

    Quantifying vegetation water content is a critical aspect of understanding plant physiology, particularly how plants cope with drought, and ecosystem water balance. Yet, we lack a method to continuously monitor plant water content, particularly on small plants. We developed a method to continuously monitor tree and shrub water content using time domain reflectometry (TDR), a measurement technique commonly used to assess soil moisture. TDR probes were fabricated and inserted into trees and shrubs. Automated measurements were made at 30 minute intervals over several months. Calibration was performed by drying cut sections of trees and shrubs in the lab while making paired TDR and weight measurements on those samples to calculate gravimetric water content. Gravimetric water content was converted to volumetric water content to create a calibration equations relating TDR measurements to water content in Betula neoalaskana, Picea mariana, Populus tremuloides, and Salix alaxensis. Our fabricated TDR probes and our calibration equations permit continuous, non-destructive, and accurate measurements of stem water content in live trees and shrubs. These data show diurnal and seasonal patterns of water content which can be incorporated into plant physiological and hydrological models.

  4. Mid-Wisconsinan environments on the eastern Great Plains

    Science.gov (United States)

    Baker, R. G.; Bettis, E. A., III; Mandel, R. D.; Dorale, J. A.; Fredlund, G. G.

    2009-05-01

    Few sites on the eastern Great Plains contain paleobotanical records for the mid-Wisconsin. We report on four sites, two stream cutbanks and two quarry exposures, ranging in age from >50 to ˜23.4 ka. The oldest site at >50 ka contains a suite of macrofossils from prairie and disturbed ground habitats, with no representation of trees, indicating an open prairie. By ˜38 ka the assemblages include aquatic, wetland, mudflat, and prairie elements with rare specimens of Populus, Betula cf. papyrifera, Salix and at the most northerly site, Picea. This assemblage suggests a prairie/parkland with interspersed marshes, cooler temperatures and increased moisture. Populus and Salix continued to be represented from ˜36 to ˜29 ka, but the only other taxon was Carex. A hiatus may be present at some time during this interval. After ˜29 ka, Picea became dominant on the uplands and it was joined by sedges in local wetlands. At sites near riverine loess sources, loess accumulation began to fill in the wetlands and organic deposition ceased some time after 29 ka.

  5. 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.

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

    Science.gov (United States)

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

    2012-11-15

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

  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. 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.

  9. 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.

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

    Science.gov (United States)

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

    2009-01-01

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

  11. [Effects of different type urban forest plantations on soil fertility].

    Science.gov (United States)

    Sun, Hui-zhen; Chen, Ming-yue; Cai, Chun-ju; Zhu, Ning

    2009-12-01

    Aimed to study the effects of different urban forest plantations on soil fertility, soil samples were collected from eight mono-cultured plantations (Larix gmelinii, Pinus sylvestris var. mongolica, Pinus tabulaeformis var. mukdensis, Phellodendron amurense, Juglans mandshurica, Fraxinus mandshurica, Betula platyphylla, and Quercus mongolica) and one mixed plantation (P. sylvestris var. mongolica + F. mandshurica + Picea koraiensis + P. amurense + B. platyphylla) established in Northeast Forestry University's Urban Forestry Demonstration Research Base in the 1950s, with two sites of neighboring farmland and abandoned farmland as the control. The soils in broadleaved forest plantations except Q. mongolica were near neutral, those in mixed plantation, L. gmelinii, P. sylvestris var. mongolica, and P. tabulaeformis var. mukdensis were slightly acidic, and that in Q. mongolica was acidic. The contents of soil organic matter, total N and P, available P and K, and hydrolysable N tended to decrease with soil depth. There existed significant differences in the chemical indices of the same soil layers among different plantations. The soil fertility was decreased in the order of F. mandshurica > P. amurense > mixed plantation > J. mandshurica > B. platyphylla > abandoned farmland > farmland > P. sylvestris var. mongolica > L. gmelinii > Q. mongolica > P. tabulaeformis var. mukdensis, suggesting that the soil fertility in broadleaved forest plantations except Q. mongolica and in mixed plantation increased, while that in needle-leaved forest plantations tended to decrease.

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

    Science.gov (United States)

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

    2011-06-01

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

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

    Directory of Open Access Journals (Sweden)

    K. Anamthawat-Jónsson

    2010-01-01

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

  14. Climate change alters leaf anatomy, but has no effects on volatile emissions from Arctic plants.

    Science.gov (United States)

    Schollert, Michelle; Kivimäenpää, Minna; Valolahti, Hanna M; Rinnan, Riikka

    2015-10-01

    Biogenic volatile organic compound (BVOC) emissions are expected to change substantially because of the rapid advancement of climate change in the Arctic. BVOC emission changes can feed back both positively and negatively on climate warming. We investigated the effects of elevated temperature and shading on BVOC emissions from arctic plant species Empetrum hermaphroditum, Cassiope tetragona, Betula nana and Salix arctica. Measurements were performed in situ in long-term field experiments in subarctic and high Arctic using a dynamic enclosure system and collection of BVOCs into adsorbent cartridges analysed by gas chromatography-mass spectrometry. In order to assess whether the treatments had resulted in anatomical adaptations, we additionally examined leaf anatomy using light microscopy and scanning electron microscopy. Against expectations based on the known temperature and light-dependency of BVOC emissions, the emissions were barely affected by the treatments. In contrast, leaf anatomy of the studied plants was significantly altered in response to the treatments, and these responses appear to differ from species found at lower latitudes. We suggest that leaf anatomical acclimation may partially explain the lacking treatment effects on BVOC emissions at plant shoot-level. However, more studies are needed to unravel why BVOC emission responses in arctic plants differ from temperate species.

  15. A heat wave during leaf expansion severely reduces productivity and modifies seasonal growth patterns in a northern hardwood forest.

    Science.gov (United States)

    Stangler, Dominik Florian; Hamann, Andreas; Kahle, Hans-Peter; Spiecker, Heinrich

    2016-10-13

    A useful approach to monitor tree response to climate change and environmental extremes is the recording of long-term time series of stem radial variations obtained with precision dendrometers. Here, we study the impact of environmental stress on seasonal growth dynamics and productivity of yellow birch (Betula alleghaniensis Britton) and sugar maple (Acer saccharum Marsh.) in the Great Lakes, St Lawrence forest region of Ontario. Specifically, we research the effects of a spring heat wave in 2010, and a summer drought in 2012 that occurred during the 2005-14 study period. We evaluated both growth phenology (onset, cessation, duration of radial growth, time of maximum daily growth rate) and productivity (monthly and seasonal average growth rates, maximum daily growth rate, tree-ring width) and tested for differences and interactions among species and years. Productivity of sugar maple was drastically compromised by a 3-day spring heat wave in 2010 as indicated by low growth rates, very early growth cessation and a lagged growth onset in the following year. Sugar maple also responded more sensitively than yellow birch to a prolonged drought period in July 2012, but final tree-ring width was not significantly reduced due to positive responses to above-average temperatures in the preceding spring. We conclude that sugar maple, a species that currently dominates northern hardwood forests, is vulnerable to heat wave disturbances during leaf expansion, which might occur more frequently under anticipated climate change.

  16. 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

    2003-07-01

    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.

  17. Availability of ectomycorrhizal fungi to black spruce above the present treeline in Eastern Labrador.

    Science.gov (United States)

    Reithmeier, Laura; Kernaghan, Gavin

    2013-01-01

    Ectomycorrhizal fungi (ECMF) are an important biotic factor in the survival of conifer seedlings under stressful conditions and therefore have the potential to facilitate conifer establishment into alpine and tundra habitats. In order to assess patterns of ectomycorrhizal availability and community structure above treeline, we conducted soil bioassays in which Picea mariana (black spruce) seedlings were grown in field-collected soils under controlled conditions. Soils were collected from distinct alpine habitats, each dominated by a different ectomycorrhizal host shrub: Betula glandulosa, Arctostaphylos alpina or Salix herbacaea. Within each habitat, half of the soils collected contained roots of ectomycorrhizal shrubs (host (+)) and the other half were free of host plants (host(-)). Forest and glacial moraine soils were also included for comparison. Fungi forming ectomycorrhizae during the bioassays were identified by DNA sequencing. Our results indicate that ECMF capable of colonizing black spruce are widespread above the current tree line in Eastern Labrador and that the level of available inoculum has a significant influence on the growth of seedlings under controlled conditions. Many of the host(-) soils possessed appreciable levels of ectomycorrhizal inoculum, likely in the form of spore banks. Inoculum levels in these soils may be influenced by spore production from neighboring soils where ectomycorrhizal shrubs are present. Under predicted temperature increases, ectomycorrhizal inoculum in soils with host shrubs as well as in nearby soils without host shrubs have the potential to facilitate conifer establishment above the present tree line.

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

    Directory of Open Access Journals (Sweden)

    Dehelean Cristina A

    2012-11-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Holocene history and environmental reconstruction of a Hercynian mire and surrounding mountain landscape based on multiple proxies

    Science.gov (United States)

    Dudová, Lydie; Hájková, Petra; Opravilová, Věra; Hájek, Michal

    2014-07-01

    We discovered the first peat section covering the entire Holocene in the Hrubý Jeseník Mountains, representing an island of unique alpine vegetation whose history may display transitional features between the Hercynian and Carpathian regions. We analysed pollen, plant macrofossils (more abundant in bottom layers), testate amoebae (more abundant in upper layers), peat stratigraphy and chemistry. We found that the landscape development indeed differed from other Hercynian mountains located westward. This is represented by Pinus cembra and Larix during the Pleistocene/Holocene transition, the early expansion of spruce around 10,450 cal yr BP, and survival of Larix during the climatic optimum. The early Holocene climatic fluctuations are traced in our profile by species compositions of both the mire and surrounding forests. The mire started to develop as a calcium-rich percolation fen with some species recently considered to be postglacial relicts (Meesia triquetra, Betula nana), shifted into ombrotrophy around 7450 cal yr BP by autogenic succession and changed into a pauperised, nutrient-enriched spruce woodland due to modern forestry activities. We therefore concluded that its recent vegetation is not a product of natural processes. From a methodological viewpoint we demonstrated how using multiple biotic proxies and extensive training sets in transfer functions may overcome taphonomic problems.

  1. New reports, phylogenetic analysis, and a key to Lactarius Pers. in the Greater Yellowstone Ecosystem informed by molecular data

    Directory of Open Access Journals (Sweden)

    Edward G. Barge

    2016-09-01

    Full Text Available The Greater Yellowstone Ecosystem (GYE, located in the Central Rocky Mountains of western North America, is one of the largest nearly intact temperate-zone ecosystems on Earth. Here, Lactarius is an important component of ectomycorrhizal communities in many habitat types, from low elevation riparian areas to high elevation conifer forests and alpine tundra. Molecular phylogenetic analyses of ITS and RPB2 gene sequences along with detailed morphological examination confirm at least 20 Lactarius species, as well as three varieties, and one unresolved species group in the GYE. Eight taxa are reported from the GYE for the first time, and nearly every major ectomycorrhizal host plant in the GYE appears to have at least one Lactarius species associated with it. Broad intercontinental distributions are suggested for alpine Salix and Betula associates, and for certain subalpine Picea and aspen (Populus spp. associates. Some species appear to be restricted to western North America with Pinus, Pseudotsuga or Abies. The distribution and/or host affinities of others is not clear due in part to ambiguous host assignment, taxonomic problems or the relative rarity with which they have been reported.

  2. 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.

  3. Late Glacial to Holocene paleoenvironmental change on the northwestern Pacific seaboard, Kamchatka Peninsula (Russia)

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    Pendea, Ionel Florin; Ponomareva, Vera; Bourgeois, Joanne; Zubrow, Ezra B. W.; Portnyagin, Maxim; Ponkratova, Irina; Harmsen, Hans; Korosec, Gregory

    2017-02-01

    We used a new sedimentary record from a small kettle wetland to reconstruct the Late Glacial and Holocene vegetation and fire history of the Krutoberegovo-Ust Kamchatsk region in eastern Kamchatka Peninsula (Russia). Pollen and charcoal data suggest that the Late Glacial landscape was dominated by a relatively fire-prone Larix forest-tundra during the Greenland Interstadial complex (GI 1) and a subarctic steppe during the Younger Dryas (GS1). The onset of the Holocene is marked by the reappearance of trees (mainly Alnus incana) within a fern and shrub dominated landscape. The Holocene Thermal Maximum (HTM) features shifting vegetational communities dominated by Alnus shrubs, diverse forb species, and locally abundant aquatic plants. The HTM is further defined by the first appearance of stone birch forests (Betula ermanii) - Kamchatka's most abundant modern tree species. The Late Holocene is marked by shifts in forest dynamics and forest-graminoid ratio and the appearance of new non-arboreal taxa such as bayberry (Myrica) and meadow rue (Filipendula). Kamchatka is one of Earth's most active volcanic regions. During the Late Glacial and Holocene, Kamchatka's volcanoes spread large quantities of tephra over the study region. Thirty-four tephra falls have been identified at the site. The events represented by most of these tephra falls have not left evidence of major impacts on the vegetation although some of the thicker tephras caused expansion of grasses (Poaceae) and, at least in one case, forest die-out and increased fire activity.

  4. Carbon constrains fungal endophyte assemblages along the timberline.

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    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.

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

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    Muilenburg, Vanessa L; Herms, Daniel A

    2012-12-01

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

  6. Stem CO2 release under illumination: corticular photosynthesis, photorespiration or inhibition of mitochondrial respiration?

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    Wittmann, Christiane; Pfanz, Hardy; Loreto, Francesco; Centritto, Mauro; Pietrini, Fabrizio; Alessio, Giorgio

    2006-06-01

    In illuminated stems and branches, CO2 release is often reduced. Many light-triggered processes are thought to contribute to this reduction, namely photorespiration, corticular photosynthesis or even an inhibition of mitochondrial respiration. In this study, we investigated these processes with the objective to discriminate their influence to the overall reduction of branch CO2 release in the light. CO2 gas-exchange measurements of young birch (Betula pendula Roth.) branches (photorespiration does not play a pre-dominant role in carbon exchange. This suppression of photorespiration was attributed to the high CO2 concentrations (C(i)) within the bark tissues (1544 +/- 227 and 618 +/- 43 micromol CO2 mol(-1) in the dark and in the light, respectively). Changes in xylem CO2 were not likely to explain the observed decrease in stem CO2 release as gas-exchange measurements before and after cutting of the branches did not effect CO2 efflux to the atmosphere. Combined fluorescence and gas-exchange measurements provided evidence that the light-dependent reduction in CO2 release can pre-dominantly be attributed to corticular refixation, whereas an inhibition of mitochondrial respiration in the light is unlikely to occur. Corticular photosynthesis was able to refix up to 97% of the CO2 produced by branch respiration, although it rarely led to a positive net photosynthetic rate.

  7. 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.

  8. Examination of the bidirectional influences of leisure activity and memory in old people: a dissociative effect on episodic memory.

    Science.gov (United States)

    Mousavi-Nasab, S-M-Hossein; Kormi-Nouri, Reza; Nilsson, Lars-Göran

    2014-08-01

    The present study examined the relationships between different types of social and cognitive activities and different types of episodic and semantic memory. A total of 794 adult men and women from five age cohorts (aged 65-85 at baseline), participating in the longitudinal Betula project on ageing, memory, and health, were included in the study. The participants were studied over 10 years (1995-2005) in three waves. Recognition and recall were used as episodic memory tasks, and knowledge and verbal fluency as semantic memory tasks. The results, after controlling for age, gender, education, and some diseases, including heart disease and hypertension, as covariates, showed unidirectional effects of social activity on episodic memory on all test occasions (β = .10). Also, episodic memory predicted change in cognitive activity for all test waves (β = .21-.22). Findings suggest that social activity can be seen as protective factor against memory decline. It also seems that episodic memory performance is a predictor of cognitive activity in old people. However, the opposite direction does not hold true.

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

    Directory of Open Access Journals (Sweden)

    Vyacheslav V Martemyanov

    Full Text Available The effects of asynchrony in the phenology of spring-feeding insect-defoliators and their host plants on insects' fitness, as well as the importance of this effect for the population dynamics of outbreaking species of insects, is a widespread and well-documented phenomenon. However, the spreading of this phenomenon through the food chain, and especially those mechanisms operating this spreading, are still unclear. In this paper, we study the effect of seasonally declined leafquality (estimated in terms of phenolics and nitrogen content on herbivore fitness, immune parameters and resistance against pathogen by using the silver birch Betula pendula--gypsy moth Lymantria dispar--nucleopolyhedrovirus as the tritrophic system. We show that a phenological mismatch induced by the delay in the emergence of gypsy moth larvae and following feeding on mature leaves has negative effects on the female pupal weight, on the rate of larval development and on the activity of phenoloxidase in the plasma of haemolymph. In addition, the larval susceptibility to exogenous nucleopolyhydrovirus infection as well as covert virus activation were both enhanced due to the phenological mismatch. The observed effects of phenological mismatch on insect-baculovirus interaction may partially explain the strong and fast fluctuations in the population dynamics of the gypsy moth that is often observed in the studied part of the defoliator area. This study also reveals some indirect mechanisms of effect related to host plant quality, which operate through the insect innate immune status and affect resistance to both exogenous and endogenous virus.

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

    Science.gov (United States)

    Martemyanov, Vyacheslav V.; Pavlushin, Sergey V.; Dubovskiy, Ivan M.; Yushkova, Yuliya V.; Morosov, Sergey V.; Chernyak, Elena I.; Efimov, Vadim M.; Ruuhola, Teija; Glupov, Victor V.

    2015-01-01

    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. PMID:26115118

  11. Vegetation shifts observed in arctic tundra 17 years after fire

    Science.gov (United States)

    Barrett, Kirsten; Rocha, Adrian V.; van de Weg, Martine Janet; Shaver, Gaius

    2012-01-01

    With anticipated climate change, tundra fires are expected to occur more frequently in the future, but data on the long-term effects of fire on tundra vegetation composition are scarce. This study addresses changes in vegetation structure that have persisted for 17 years after a tundra fire on the North Slope of Alaska. Fire-related shifts in vegetation composition were assessed from remote-sensing imagery and ground observations of the burn scar and an adjacent control site. Early-season remotely sensed imagery from the burn scar exhibits a low vegetation index compared with the control site, whereas the late-season signal is slightly higher. The range and maximum vegetation index are greater in the burn scar, although the mean annual values do not differ among the sites. Ground observations revealed a greater abundance of moss in the unburned site, which may account for the high early growing season normalized difference vegetation index (NDVI) anomaly relative to the burn. The abundance of graminoid species and an absence of Betula nana in the post-fire tundra sites may also be responsible for the spectral differences observed in the remotely sensed imagery. The partial replacement of tundra by graminoid-dominated ecosystems has been predicted by the ALFRESCO model of disturbance, climate and vegetation succession.

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

    Science.gov (United States)

    Bokszczanin, Kamila Ł; Przybyła, Andrzej A

    2012-03-01

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

  13. 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.

  14. 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.

  15. 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.

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

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    Alexis Achim

    2013-09-01

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

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

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    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

  18. Climate and vegetation history from a 14,000-year peatland record, Kenai Peninsula, Alaska

    Science.gov (United States)

    Jones, Miriam C.; Peteet, Dorothy M.; Kurdyla, Dorothy; Guilderson, Thomas

    2009-09-01

    Analysis of pollen, spores, macrofossils, and lithology of an AMS 14C-dated core from a subarctic fen on the Kenai Peninsula, Alaska reveals changes in vegetation and climate beginning 14,200 cal yr BP. Betula expansion and contraction of herb tundra vegetation characterize the Younger Dryas on the Kenai, suggesting increased winter snowfall concurrent with cool, sunny summers. Remarkable Polypodiaceae (fern) abundance between 11,500 and 8500 cal yr BP implies a significant change in climate. Enhanced peat preservation and the occurrence of wet meadow species suggest high moisture from 11,500 to 10,700 cal yr BP, in contrast to drier conditions in southeastern Alaska; this pattern may indicate an intensification and repositioning of the Aleutian Low (AL). Drier conditions on the Kenai Peninsula from 10,700 to 8500 cal yr BP may signify a weaker AL, but elevated fern abundance may have been sustained by high seasonality with substantial snowfall and enhanced glacial melt. Decreased insolation-induced seasonality resulted in climatic cooling after 8500 cal yr BP, with increased humidity from 8000 to 5000 cal yr BP. A dry interval punctuated by volcanic activity occurred between 5000 and 3500 cal yr BP, followed by cool, moist climate, coincident with Neoglaciation. Tsuga mertensiana expanded after ~ 1500 cal yr BP in response to the shift to cooler conditions.

  19. 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.

  20. From soil to leaves--aluminum fractionation by single step extraction procedures in polluted and protected areas.

    Science.gov (United States)

    Frankowski, Marcin; Zioła-Frankowska, Anetta; Siepak, Jerzy

    2013-09-30

    The paper presents the fractionation of aluminum in the samples of soil and plants of different species using a selective single-step extraction method. The study was conducted in the area located near a chemical plant, which for many years served as a post-crystallization leachate disposal site storing chemical waste (sector I), and in the area around the site: in Wielkopolski National Park, Rogalin Landscape Park and toward the infiltration ponds at the "Dębina" groundwater well-field for the city of Poznań (Poland) (sector II). The results of aluminum fractionation in samples of soil, leaves and plants showed heavy pollution with aluminum, especially in the water soluble aluminum fraction - Alsw (maximum concentration of aluminum in soil extract was 234.8 ± 4.8 mg kg(-1), in the leaves of Betula pendula it was 107.4 ± 1.8 mg kg(-1) and in the plants of Artemisia vulgaris (root) and Medicago sativa (leaves) it amounted to 464.7 ± 10.7 mg kg(-1)and 146.8 ± 1.2 mg kg(-1) respectively). In addition, the paper presents the problem of organic aluminum fractionation in biological samples and it shows the relationship between aluminum concentration in soil and the analysed woody and herbaceous species.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. The response of different plant life forms to natural environment changes

    Directory of Open Access Journals (Sweden)

    Schmidt Svetlana

    2011-03-01

    Full Text Available This paper contains test results revealing norm and stress reactions of various life-form plants: trees — Betula pendula Roth, Tilia platyphyllos Scop., Pinus sylvetris L; water-plant -Galium palustre L.; grass — Solidago Canadensis; cereal — Secale cereal L. Collection and processing of the material was made in the area of Berlin/Brandenburg, Germany. Clark sensor-based method made it possible to determine the amount and rate of the oxygen evolution by plants in the dark and light phase. Under the reaction norm the average amount of the oxygen evolved and the average rate of metabolism processes during dark and light phases are changing simultaneously. Parabolic and periodic dependences of these changes during the vegetation period has been found. Under the stress reaction (drought, illness the rate of metabolism dark reactions is increased by 2—3 times as compared with light reactions. The obtained results may be use for bioindication of the climate change in the Baltic Region.

  11. Reakcii rastenij raznyh zhiznennyh form na izmenenija prirodnoj sredy [The response of different plant life forms to natural environment changes

    Directory of Open Access Journals (Sweden)

    Schmidt Svetlana

    2011-01-01

    Full Text Available This paper contains test results revealing norm and stress reactions of various life-form plants: trees — Betula pendula Roth, Tilia platyphyllos Scop., Pinus sylvetris L; water-plant -Galium palustre L.; grass — Solidago Canadensis; cereal — Secale cereal L. Collection and processing of the material was made in the area of Berlin/Brandenburg, Germany. Clark sensor-based method made it possible to determine the amount and rate of the oxygen evolution by plants in the dark and light phase. Under the reaction norm the average amount of the oxygen evolved and the average rate of metabolism processes during dark and light phases are changing simultaneously. Parabolic and periodic dependences of these changes during the vegetation period has been found. Under the stress reaction (drought, illness the rate of metabolism dark reactions is increased by 2—3 times as compared with light reactions. The obtained results may be use for bioindication of the climate change in the Baltic Region.

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

    Directory of Open Access Journals (Sweden)

    Klimek Andrzej

    2014-12-01

    Full Text Available The Oribatida (known as moss mites or beetle mites increase the breakdown of organic material in the soil. The paper analyses the dynamics of their abundance and number of species after various treatments enriching the soil in 4 study areas: afforested post-agricultural area in the Tuchola Forest, afforested degraded post-military training area in Bydgoszcz-Jachcice, and forest nurseries at Białe Błota and Bielawy. The results show that in post-agricultural and degraded soils at the initial stages of forest succession, the density and number of species of oribatid mites were low, even after phyto-land-improvement (afforestation and lupin as green manure. In the forest nurseries, however, we recorded a positive effect of soil revitalizing after mulching with forest ectohumus (i.e. organic surface layer of the soil. The inoculation of soils with forest mesofauna appeared more effective in nursery plantations of silver birch (Betula pendula and small-leaved lime (Tilia cordata, as compared with Scots pine (Pinus sylvestris. Thus to revitalize degraded soils effectively and to accelerate forest succession, apart from phytoland- improvement, it is advisable also to reintroduce mesofauna, e.g. with the use of forest ectohumus.

  13. The distribution of late-Quaternary woody taxa in northern Eurasia: evidence from a new macrofossil database

    Science.gov (United States)

    Binney, Heather A.; Willis, Katherine J.; Edwards, Mary E.; Bhagwat, Shonil A.; Anderson, Patricia M.; Andreev, Andrei A.; Blaauw, Maarten; Damblon, Freddy; Haesaerts, Paul; Kienast, Frank; Kremenetski, Konstantin V.; Krivonogov, Sergey K.; Lozhkin, Anatoly V.; MacDonald, Glen M.; Novenko, Elena Y.; Oksanen, Pirita; Sapelko, Tatiana V.; Väliranta, Minna; Vazhenina, Ludmila

    2009-11-01

    We present a database of late-Quaternary plant macrofossil records for northern Eurasia (from 23° to 180°E and 46° to 76°N) comprising 281 localities, over 2300 samples and over 13,000 individual records. Samples are individually radiocarbon dated or are assigned ages via age models fitted to sequences of calibrated radiocarbon dates within a section. Tree species characteristic of modern northern forests (e.g. Picea, Larix, tree-Betula) are recorded at least intermittently from prior to the last glacial maximum (LGM), through the LGM and Lateglacial, to the Holocene, and some records locate trees close to the limits of the Scandinavian ice sheet, supporting the hypothesis that some taxa persisted in northern refugia during the last glacial cycle. Northern trees show differing spatio-temporal patterns across Siberia: deciduous trees were widespread in the Lateglacial, with individuals occurring across much of their contemporary ranges, while evergreen conifers expanded northwards to their range limits in the Holocene.

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

    Science.gov (United States)

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

    2012-04-01

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

  15. Leaching of nitrogen and phosphorus during production of forest seedlings in containers.

    Science.gov (United States)

    Juntunen, Marja-Liisa; Hammar, Taina; Rikala, Risto

    2002-01-01

    Little information is available concerning the contamination risk caused by forest seedling nurseries to local surface and ground waters compared with agricultural and horticultural production. Leaching of nitrogen (N) and phosphorus (P) through peat growing medium in containers and nutrient uptake of seedlings were monitored in production of silver birch (Betula pendula Roth), Norway spruce [Picea abies (L.) Karst], and Scots pine (Pinus sylvestris L.) seedlings. About half of the applied nutrients (total amount applied = 149 to 260 kg N ha(-1) and 60 to 108 kg P ha(-1)) was premixed into the peat medium, as is usual in Finnish nursery practice, and the other half was applied to seedlings in liquid form with mobile booms. Depending on tree species, 11 to 19% of the applied N was recovered in leachates and 15 to 63% in seedlings. The undiscovered proportion varied from 19 to 71%. The amounts of leached N were 19 to 41 kg ha(-1). Only 5 to 31% of the applied P was recovered in seedlings; 16 to 64% (11 to 56 kg ha(-1)) was found in leachates. Total N and P load to the environment may increase substantially if nutrients applied in liquid fertilization outside container trays are included. Consequently, it is important to determine the sources of nutrient load in container seedling production to mitigate the risk of environment contamination.

  16. 桑黄多糖对小鼠骨髓造血机能损伤的保护作用

    Institute of Scientific and Technical Information of China (English)

    王中喜; 王晓娟; 田玉菊

    2006-01-01

    桑黄为多孔菌科真菌针层孔菌Phellinus igniarius(L.ex Fr.)Qud.的子实体。药物名称桑黄,别名桑臣、胡孙眼。生长在杨(Populus spp.)、柳(Salix spp.)、白桦(Betula phtyphylla Suk.)等阔叶树的树干上。在日本,正品桑黄被认为是主要寄生在桑树上,拉丁学名为Phellinus linteus.主要产于长岛县男女群岛的女岛,目前在日本和韩国主要作为免疫增强剂和癌症治疗的辅助药物。具有较高的抑制肿瘤及抗病毒活性。是目前已知菌物界抗癌活性有效率排在第一位的菌类植物。

  17. 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%.

  18. 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.

  19. 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.

  20. 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

    2011-01-01

    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.

  1. Extinct mountain goat ( Oreamnos harringtoni) in Southeastern Utah

    Science.gov (United States)

    Mead, Jim I.; Agenbroad, Larry D.; Phillips, Arthur M.; Middleton, Larry T.

    1987-05-01

    The extinct Harrington's mountain goat ( Oreamnos harringtoni Stock) is predominantly known from dry cave localities in the Grand Canyon, Arizona, in addition to two sites in the Great Basin, Nevada, and from San Josecito Cave, Nuevo Leon, Mexico. A dry shelter in Natural Bridges National Monument, on the central Colorado Plateau, southeastern Utah, preserves numerous remains of the extinct mountain goat in addition to pack rat middens. Remains from a 100-cm stratigraphic profile indicate that O. harringtoni lived on the plateau >39,800 yr B.P., the oldest directly dated find of extinct mountain goat. Plant macrofossils indicate that Engelmann's spruce ( Picea engelmannii), limber pine ( Pinus flexilis), rose ( Rosa cf. woodsii), and Douglas fir ( Pseudotsuga menziesii) grew during the late Pleistocene where a riparian and a pinyon-juniper ( Pinus edulis-Juniperus osteosperma) community now predominates; Douglas fir are found only in mesic, protected, north-facing areas. Limber pine, Douglas fir, bark, and grasses were the major dietary components in the dung. A springtime diet of birch ( Betula) is determined from pollen clumps in dung pellets.

  2. Traditional Uses of Plants in the Tolfa–Cerite–Manziate Area (Central Italy

    Directory of Open Access Journals (Sweden)

    Paolo Maria Guarrera

    2015-09-01

    Full Text Available Traditional knowledge of local plant uses is rapidly fading away, especially in rural Mediterranean areas. We carried out ethnobotanical research in 2010-2011 in order to investigate the local knowledge of wild plants in the Tolfa–Cerite–Manziate area of Italy (Latium, district of Rome. We carried out a total of 45 semi-structured interviews with farmers, herders, and fishers. Here, a simple diachronic comparison is made between the current study and a previous one conducted in some of the villages of the study area to highlight potential losses of traditional knowledge of local plants. We documented a total of 102 plant species, belonging to 48 families, along with their uses (excluding food uses. We also reported some non-plant based remedies that were primarily used in veterinary medicine. Some plant uses, especially for making handicrafts, have not been reported previously (e.g., those of Celtis australis L. Cannabaceae, Betula pendula Roth Betulaceae. Many plant uses are no longer remembered in the area, which indicates a loss of local ethnobotanical knowledge.

  3. 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.

  4. Transfer of elements relevant to nuclear fuel cycle from soil to boreal plants and animals in experimental meso- and microcosms.

    Science.gov (United States)

    Tuovinen, Tiina S; Kasurinen, Anne; Häikiö, Elina; Tervahauta, Arja; Makkonen, Sari; Holopainen, Toini; Juutilainen, Jukka

    2016-01-01

    Uranium (U), cobalt (Co), molybdenum (Mo), nickel (Ni), lead (Pb), thorium (Th) and zinc (Zn) occur naturally in soil but their radioactive isotopes can also be released into the environment during the nuclear fuel cycle. The transfer of these elements was studied in three different trophic levels in experimental mesocosms containing downy birch (Betula pubescens), narrow buckler fern (Dryopteris carthusiana) and Scandinavian small-reed (Calamagrostis purpurea ssp. Phragmitoides) as producers, snails (Arianta arbostorum) as herbivores, and earthworms (Lumbricus terrestris) as decomposers. To determine more precisely whether the element uptake of snails is mainly via their food (birch leaves) or both via soil and food, a separate microcosm experiment was also performed. The element uptake of snails did not generally depend on the presence of soil, indicating that the main uptake route was food, except for U, where soil contact was important for uptake when soil U concentration was high. Transfer of elements from soil to plants was not linear, i.e. it was not correctly described by constant concentration ratios (CR) commonly applied in radioecological modeling. Similar nonlinear transfer was found for the invertebrate animals included in this study: elements other than U were taken up more efficiently when element concentration in soil or food was low.

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

    Directory of Open Access Journals (Sweden)

    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%.

  6. Changes in petiole hydraulic properties and leaf water flow in birch and oak saplings in a CO{sub 2}-enriched atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, N.; Morii, N.; Koike, T. [Hokkaido Univ., Sapporo (Japan). Graduate School of Agriculture; Ueda, T. [Hokkaido DALTON, Sapporo (Japan); Funada, R. [Tokyo Univ. of Agriculture and Technology, Tokyo (Japan). Faculty of Agriculture; Takagi, K.; Hiura, T.; Sasa, K. [Hokkaido Univ., Sapporo (Japan). Forests, Field Science Center for Northern Biosphere

    2008-02-15

    This study examined the water flow and petiole hydraulic properties in the individual leaves of Betula maximowicziana Regel and ring-porous Quercus mongolica Fish. ex Ledeb ssp. crispula Menitsky. The aim of the study was to examine the relationship between water flow, hydraulic properties and elevated carbon dioxide (CO2). The effects of elevated CO{sub 2} on sun and shade leaves of 2 petioles were investigated in order to examine structural changes in response to CO{sub 2}. The study was conducted at the Sapporo Experimental Forest in Japan, where a free air CO{sub 2} enrichment system was used to maintain CO{sub 2} levels. Results of the study demonstrated that elevated CO{sub 2} levels consistently decreased water flow, including leaf-specific hydraulic conductivity and total vessel area of the petiole in leaves exposed to the sun. Elevated CO{sub 2} levels had no impact on the hydraulic conductivity of shade leaves. It was concluded that changes in water flow were also associated with changes in petiole hydraulic properties. 57 refs., 2 tabs., 4 figs.

  7. 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.

  8. 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.

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

    Science.gov (United States)

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

    2015-11-12

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

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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.

  13. Addendum to aphids’ fauna, feeding on flowering plants in Krasnoyarsk krai

    Directory of Open Access Journals (Sweden)

    D. L. Grodnitsky

    2016-06-01

    Full Text Available The paper reports on new and previously known data on insufficiently studied fauna of aphids living on flowering plants in Krasnoyarsk region, the main part of a vast geographical province named Central or Middle Siberia, depending on terminology used by authors of literature sources. From physical geography viewpoint, the surveyed territory belongs to the Yenisey river basin. Aphids are an ecologically and morphologically diverse group of insects included in 11 families of the suborder Aphidinea in insect fauna of Russian Federation and 25 families in the world’s fauna. Geographical location, dates of collection of aphid colonies are presented with identification of species-specific feeding preferences. First found in Siberia were Symydobius nanae, Euceraphis betulae, Cavariella cicutae, C. konoi, Uroleucon (Dactynotus aeneum, U. giganteum, U. nigrocampalulae, U. trachelii, Aphis agrimoniae, A. coronillae, A. mongolica, A. neothalictri, A. pruni, A. pseudocomosa, A. pulsatillae, A. sambuci, A. (Debilisiphon umbelliferarum. Collected for the first time from willow were Betacallis comes (normally feeds on birch and alder, B. quadrituberculata (common on birch, colonies of Metopeurum fuscoviride were first found on Achillea millefolium. Aphis craccivora was previously collected from plants of different families, but was never seen on Cruciferae (Capsella bursa­pastoris. Aphis frangulae was concidered to feed exclusively on buckthorn, however, it was found on Chamaenerion angustifolium. Judging on diversity of host species, some aphids may be more important for agriculture than it was previously thought. A general review of Krasnoyarsk Krai aphid fauna is suggested for the first time ever.

  14. 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.

  15. Combining microtomy and confocal laser scanning microscopy for structural analyses of plant-fungus associations.

    Science.gov (United States)

    Rath, Magnus; Grolig, Franz; Haueisen, Janine; Imhof, Stephan

    2014-05-01

    The serious problem of extended tissue thickness in the analysis of plant-fungus associations was overcome using a new method that combines physical and optical sectioning of the resin-embedded sample by microtomy and confocal microscopy. Improved tissue infiltration of the fungal-specific, high molecular weight fluorescent probe wheat germ agglutinin conjugated to Alexa Fluor® 633 resulted in high fungus-specific fluorescence even in deeper tissue sections. If autofluorescence was insufficient, additional counterstaining with Calcofluor White M2R or propidium iodide was applied in order to visualise the host plant tissues. Alternatively, the non-specific fluorochrome acid fuchsine was used for rapid staining of both, the plant and the fungal cells. The intricate spatial arrangements of the plant and fungal cells were preserved by immobilization in the hydrophilic resin Unicryl™. Microtomy was used to section the resin-embedded roots or leaves until the desired plane was reached. The data sets generated by confocal laser scanning microscopy of the remaining resin stubs allowed the precise spatial reconstruction of complex structures in the plant-fungus associations of interest. This approach was successfully tested on tissues from ectomycorrhiza (Betula pendula), arbuscular mycorrhiza (Galium aparine; Polygala paniculata, Polygala rupestris), ericoid mycorrhiza (Calluna vulgaris), orchid mycorrhiza (Limodorum abortivum, Serapias parviflora) and on one leaf-fungus association (Zymoseptoria tritici on Triticum aestivum). The method provides an efficient visualisation protocol applicable with a wide range of plant-fungus symbioses.

  16. 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.

  17. 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.

  18. 伯乐树木材物理力学性质的研究%Study on Physical and Mechanical Properties of Bretschneidera sinensis Wood

    Institute of Scientific and Technical Information of China (English)

    陈奕良; 林鹏; 叶朝坤; 俞友明; 黄华宏; 骆文坚

    2010-01-01

    对伯乐树(Bretschneidera sinensis)木材的物理力学性质进行了测定与分析,结果表明:伯乐树木材的气干密度为0.636 g/cm3,体积干缩系数为0.65%,顺纹抗压强度为57.3 MPa,弦向抗弯强度为108.1 MPa,综合强度为165.4 MPa,冲击韧性46.5 kJ/m2,与光皮桦(Betula luminifera)、鹅掌楸(Liriodendron chinense)、水青冈(Fagus longipetiolata)、水曲柳(Fraxinus mandschurica)、核桃(Juglansregia)、黄檀(Dalbergia hupeana)、枫香(Liquidambar formosana)、柞木(Xylosma racemosum)8种阔叶树种木材相比,其材性属中等.

  19. 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.

  20. 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.

  1. ISOLATION, CLONING AND CHARACTERIZATION OF ACTIN-ENCODING cDNAs FROM Jatropha curcas L. IP-2P

    Directory of Open Access Journals (Sweden)

    Kinya Akashi

    2011-11-01

    Full Text Available Actin is a major component of the plant cytoskeleton, so all cells contain this protein. Actin is expressed constitutivelyand is involved in basic housekeeping functions required for cell maintenance. Because of this, it has been frequentlyused as an internal control to normalize changes in gene expressions analysis. Actually, the information of nucleotidesequence of actin gene of Jatropha curcas L. population IP-2P from Indonesia is not available yet. The objective of thisresearch was to isolate, clone and characterize cDNA of actin genes of J. curcas IP-2P. Three partial actin genesequences had been successfully isolated by PCR using total cDNA as template, and actin primer designed fromconserved region of Arabidopsis thaliana. Nucleotide sequence analysis showed that the length of JcACT fragment is610, 534, and 701 bp encoding 203, 177, and 234 amino acids respectively. Local alignment analysis based on mRNAsequences shows that JcACT fragment shares 98% similarity with actin mRNA of Hevea brasiliensis and 99% withactin mRNA of Ricinus communis. Based on deduced amino acid sequence, JcACT is 100% identical to actins fromPrunus salicina, Gossypium hirsutum, and Betula luminifera. Even though these clones of cDNA are not completed yet,they can be used as reference in J. curcas L. gene expression analysis.

  2. 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.

  3. 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.

  4. 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.

  5. THE CLASS QUERCO-FAGETEA SYLVATICAE IN SICILY: AN EXAMPLE OF BOREO-TEMPERATE VEGETATION IN THE CENTRAL MEDITERRANEAN REGION

    Directory of Open Access Journals (Sweden)

    C. Brullo

    2012-04-01

    Full Text Available A syntaxonomical revision of the class Querco-Fagetea sylvaticae in Sicily, based on literature data and unpublished relevés, is presented. This class groups the mesophilous woods characterized by the dominance of deciduous trees (e.g. Fagus sylvatica, Quercus sp. pl., Acer sp. pl., and more rarely by conifers (Taxus baccata, Pinus nigra subsp. calabrica, as well as by other broadleaved trees, such as Betula aetnensis, Populus tremula, Castanea sativa. In Sicily, these woody communities are widespread in the northern and north-eastern districts of the island, chiefly on the highest peaks (Madonie, Nebrodi, Peloritani, and Etna. This class is represented in Sicily by two, both floristically and ecologically well differentiated orders: Fagetalia sylvaticae, with the sole alliance Geranio versicoloris-Fagion sylvaticae, and Quercetalia pubescenti-petraeae, with the endemic alliance Pino calabricae-Quercion congestae. On the whole, 22 associations have been recognized within the class Querco-Fagetea and for each of them nomenclature, floristic assessment, ecology, syndinamic relationships, and chorology are examined.

  6. Temperature as a modifier of plant-herbivore interaction.

    Science.gov (United States)

    Yang, Shiyong; Ruuhola, Teija; Haviola, Sanna; Rantala, Markus J

    2007-03-01

    Temperature directly affects the growth, survival, and development rates of poikilothermic insect herbivores; it may also have an important indirect impact, via the activities of plant defensive enzymes. The effects of wounding birch leaves and temperature on the growth and development rates of a Lepidopteran moth, Epirrita autumnata, were studied. We also examined the activities of a mountain birch (Betula pubescesns spp. czerepanovii) defensive enzymes, specifically the polyphenoloxidases (PPOs), in relation to temperature and wounding. The optimal temperature for early instars in terms of survival and developmental rates was between +15 and 20 degrees C. Wounding treatment had different effects on birch PPO activity depending on the temperature: at +12 degrees C, wounding decreased the activity, suggesting induced amelioration at that temperature, whereas at +25 degrees C, wounding increased the activity, suggesting induced resistance. However, larval growth was retarded slightly, but significantly, on the leaves of wounded twigs at both temperatures. Both PPO activity and larval growth rates were affected within 12 h, indicating the existence of a transcription- and translation-independent defense system in birch leaves. We suggest that underlying the increase in PPO activity and the decrease in larval growth rate may be H2O2, which has been shown to accumulate in response to wounding. Our results also provide a possible biological mechanism for the hypothesis that low temperatures promote the success of E. autumnata and other Lepidopteran larvae via decreased defensive enzyme activities of host plants at lower temperatures.

  7. Changes in structural and chemical components of wood delignified by fungi

    Energy Technology Data Exchange (ETDEWEB)

    Blanchette, R.A.; Otjen, L.; Effland, M.J.; Eslyn, W.E.

    1985-01-01

    Cerrena unicolor, Ganoderma applanatum, Ischnoderma resinosum and Poria medulla-panis were associated with birch (Betula papyrifera) wood that had been selectively delignified in the forest. Preferential lignin degradation was not uniformly distributed throughout the decayed wood. A typical white rot causing a simultaneous removal of all cell wall components was also present. In the delignified wood, 95 to 98% of the lignin was removed as well as substantial amounts of hemicelluloses. Scanning and transmission electron microscopy were used to identify the micromorphological and ultrastructural changes that occurred in the cells during degradation. In delignified areas the compound middle lamella was extensively degraded causing a defibration of cells. The secondary wall, especially the S2 layer, remained relatively unaltered. In simultaneously white-rotted wood all cell wall layers were progressively removed from the lumen toward the middle lamella causing erosion troughs or holes to form. Large voids filled with fungal mycelia resulted from a coalition of degraded areas. Birch wood decayed in laboratory soil-block tests was also intermittently delignified, selective delignification, sparsely distributed throughout the wood, and a simultaneous rot resulting in the removal of all cell wall components were evident. SEM appears to be an appropriate technique for examining selectively delignified decayed wood. 30 references.

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

    Directory of Open Access Journals (Sweden)

    Cîntă-Pînzaru Simona

    2012-07-01

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

  9. Experimental warming effects on the bacterial community structure and diversity

    Science.gov (United States)

    Kim, W.; Han, S.; Adams, J.; Son, Y.

    2014-12-01

    The objective of this study is to investigate the responses of soil bacterial community to future temperature increase by conducting open-field warming experiment. We conducted an open-field experimental warming system using infra-red heater in 2011 and regulated the temperature of warmed plots by 3oC higher than that of control plots constantly. The seeds of Pinus densiflora, Abies holophylla, Abies koreana, Betula costata, Quercus variabilis, Fraxinus rhynchophylla, and Zelkova serrata were planted in each 1 m × 1 m plot (n=3) in April, 2012. We collected soil samples from the rhizosphere of 7 tree species. DNA was extracted and PCR-amplified for the bacterial 16S gene targeting V1-V3 region. The paired-end sequencing was performed at Beijing Genome Institute (BGI, Hong Kong, China) using 2× 100 bp Hiseq2000 (Illumina). This study aimed to answer the following prediction/hypothesis: 1) Experimental warming will change the structure of soil bacterial community, 2) There will be distinct 'indicator group' which response to warming treatment relatively more sensitive than other groups. 3) Warming treatment will enhance the microbial activity in terms of soil respiration. 4) The rhizoplane bacterial communities for each of 7 tree species will show different response pattern to warming treatment. Since the sequence data does not arrive before the submission deadline, therefore, we would like to present the results and discussions on December 2014, AGU Fall Meeting.

  10. 松茸发生地植被特征及功能分区%Vegetation Characteristics and Functional Division of Tricholoma matsutake habitat

    Institute of Scientific and Technical Information of China (English)

    孙刚; 王振堂

    2000-01-01

    研究了长白山松茸发生地的植被特征及功能分区.结果表明,松茸发生地植被组成比较简单,冠层稀疏,郁闭度较低(一般在0.5~0.6之间).松茸主要生长于赤松(Pinus densiflora)林中、岳桦(Betula ermanii)、杜鹃(Rhododendron dahuricum)和羊胡子苔草(Carex callitrichos)是赤松最常见的伴生种群.以松茸生产为指标,将赤松林划分为适宜松茸生长的高产天然赤松针阔混交林、低产或不产松茸的疏林型天然赤松林、不产松茸的密林型天然赤松林和人工赤松林4类.松茸保护区可分为生态环境保障带、松茸产出带和缓冲带.

  11. 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.

  12. Woody-biomass production in Michigan: species, genotype, and cultural investigations

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.O.

    1984-01-01

    A stepwise approach was adopted in 1978 for developing a comprehensive woody-biomass production system for Michigan. The program consisted of four phases: 1) identification of the most promising biomass species through trial plantings on abandoned agricultural fields and cleared forest stands, 2) preliminary yield comparisons of several species growing in existing experimental plantations, 3) species improvement using standard tree improvement techniques, and 4) development of cultural techniques designed to optimize woody-biomass yield from energy plantations. This dissertation summarizes results of research in each of these areas. Species recommendations for each of three climatic zones in Michigan are based on survival and growth of 23 species at nine oil-field sites after four growing seasons. Pinus sylvestris, P. banksiana, P. resinosa, P. nigra x P. densiflora, Larix leptolepis, Alnus glutinosa, and Picea abies are recommended for use in the Upper Peninsula; Pinus sylvestris, P. resinosa, P. nigra x P. densiflora, Larix leptolepis, Alnus glutinosa, Picea abies, and Quercus robur are recommended for use in the northern Lower Peninsula; and Pinus sylvestris, Alnus glutinosa, Larix leptolepis, Populus, Quercus robur, Fraxinus pennsylvanica, and Salix are recommended for use in the southern Lower Peninsula of Michigan. Yield predictor equations were developed and yields analyzed for 13 species. The best yielding species in the older plantations (14- 16-years old) were Pinus nigra x P. densiflora and Betula alleghaniensis. The best species in the group of younger plantations (five- to nine-years old) were a Populus hybrid mixture and Ailanthus altissima.

  13. 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.

  14. Landscape Mapping and Tree Diversity Assessment of Pangi Valley: A Remote Tribal Area of Himachal Pradesh in Western Himalaya, India

    Directory of Open Access Journals (Sweden)

    Amit KUMAR

    2013-12-01

    Full Text Available Pangi valley in Chamba district of Himachal Pradesh is one of the remote tribal areas in Indian western Himalaya. The plant resources in its landscapes are flourishing under least anthropogenic conditions. For social upliftment of the tribals in this area, a number of developmental activities are being implemented by the government. A study was conducted for mapping of its landuse/landcover using satellite remote sensing to identify major forested landscapes in the region. It was followed by a detailed random stratified sampling of the forested landscapes for phytosociological estimation of its tree species. The 21.97 % of study area was estimated under forests followed by Scrublands and Grassy meadows (18.24 %. Majority of area (54.05 % was Snow and Scree slopes. Among the forests, maximum area was occupied by Mixed Broad Leaved Forest LSE type (36.08% followed by Cedrus deodara (26.94% and Betula utilis (18.07% forest LSE types. These species, owing to immense medicinal properties and value for their economic utilization, feature in threatened and endangered category list of plants. It is, therefore, recommended that the developmental activities may be implemented in scientific way, which may not pose threat to bioresources in this region.

  15. 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.

  16. 红花尔基自然保护区天然樟子松林种内种间竞争分析%Analyses of intraspecific and interspecific competition of Pinus sylvestris var. mongolica natural forest in Honghuaerji Nature Reserve of Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    毛磊; 杨丹青; 王冬梅; 杨晓晖

    2008-01-01

    运用Hegyi单木竞争指数分析了内蒙古红花尔基自然保护区天然樟子松(Pinus sylvestris var.mongolicaLitv.)林内所有胸径大于2 cm的樟子松、山杨(Populus davidiana Dode.)、白桦(Betula platyphylla Suk.)和山荆子(Malus baccata L.)的种内和种间竞争强度.结果表明,样地中主要的竞争木和对象木均为樟子松和白桦;樟子松的种内竞争强度(0.534)远大于种间竞争强度.随径级的增大,樟子松的种内竞争强度逐渐减小,且与胸径存在幂函数关系CI=A·D-B.胸径达到30 cm后,樟子松种内竞争强度变化不明显.作为竞争木,樟子松对其他树种产生了较大的竞争压力.

  17. Airborne pollen assemblages and weather regime in the central-eastern Loess Plateau, China

    Science.gov (United States)

    Li, Yuecong; Ge, Yawen; Xu, Qinghai; Bunting, Jane M.; Lv, Suqing; Wang, Junting; Li, Zetao

    2015-04-01

    This paper presents the results of pollen trapping studies designed to quantify the pollen assemblages carried in the winds of the Loess Plateau in Luochuan and Hunyuan. The one-year-collection samples analysis results show that pollen assemblages can be more sensitive to the change of climate than the vegetation composition, because of the change of pollen production. The analysis results of pollen traps in different weather regimes indicate that the pollen influx coming from dust weather contribute more to the total pollen influx than that coming from non-dust weather. The wind speed is the most important influenced factor to pollen assemblages, then the mean temperature and the mean relative humidity, the wind direction also contributes some. Strong wind coming from dust direction can make the percent and influx of Artemisia and Chenopodiaceae increase obviously with averagely higher than over 2.7 times in dust weather than in non-dust samples. The influences of wind speed and wind direction are not serious to some arboreal pollen such as Rosaceae, Quercus, Betula, Pinus and Ostryopsis, which are mainly influenced by temperature or the relative humidity such as Salix, Hippophae, Carpinus, Brassicaceae, Cupressaceae, Fabaceae.

  18. Surface pollen and its relationship to vegetation in the Zoige Basin, eastern Tibetan Plateau

    Science.gov (United States)

    Li, Furong; Zhao, Yan; Sun, Jinghui; Zhao, Wenwei; Guo, Xiaoli; Zhang, Ke

    2011-09-01

    We use a data set of 23 surface pollen samples from moss polsters in the Zoige Basin to explore the relationship between modern pollen assemblages and contemporary vegetation patterns. The surface pollen samples spanned four types of plant communities: Carex muliensis marsh, Stipa and Kobresia meadow, Carex-dominated forb meadow and Sibiraea angustata scrub. Principal-components analysis (PCA) was used to determine the relationships between modern pollen and vegetation and environmental variables. The results show that the pollen assemblages of surface moss samples generally reflect the features of the modern 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.

  19. 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.

  20. Nutritional ecology of the formosan subterranean termite (Isoptera: Rhinotermitidae): feeding response to commercial wood species.

    Science.gov (United States)

    Morales-Ramos, J A; Rojas, M G

    2001-04-01

    The feeding preferences of the Formosan subterranean termite, Coptotermes formosanus Shiraki, were tested in three separate experiments on 28 different wood species. Experiment 1 was a multiple-choice test designed to test relative preferences among 24 wood species commercially available in New Orleans, LA. Experiment 2 was a similar study designed to test relative preferences among 21 wood species shown or reported to be unpalatable to the Formosan subterranean termite. Experiment 3 was a no-choice test to examine the feeding deterrence of the 10 least preferred wood species. Preference was determined by consumption rates. Birch (Betula alleghaniensis Britton), red gum (Liquidambar styraciflua L.), Parana pine [Araucaria angustifolia (Bert.) 1, sugar maple (Acer saccharum Marsh.), pecan (Carya illinoensis Wangenh.), and northern red oak (Quercus rubra L.) were the most preferred species by C. formosanus in order of consumption rate. All of these species were significantly more preferred than southern yellow pine (Pinus taeda L.), widely used for monitoring. Sinker cypress [ = old growth bald cypress, Taxodium distichum (L.)], western red cedar (Thuja plicata Donn), Alaskan yellow cedar (Chamaecyparis nootkatensis D. Don), eastern red cedar (Juniperus virginiana L.), sassafras [Sassafras albidum (Nutt.)], Spanish cedar (Cedrella odorata L.), Honduras mahogany (Swietenia macrophyla King), Indian rosewood (Dalbergia latifolia Roxb.), Honduras rosewood (D. stevensonii Standl.), and morado (Machaerium sp.) induced significant feeding deterrence and mortality to C. formosanus. The last eight species produced 100% mortality after 3 mo.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

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

    Science.gov (United States)

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

    2013-02-01

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

  7. 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.

  8. 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.

  9. 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.

  10. One Century of Treeline Change and Stability - Experiences from the Swedish Scandes

    Directory of Open Access Journals (Sweden)

    Leif Kullman

    2010-03-01

    Full Text Available This paper elaborates and visualizes processes recorded in a recent regional and multi-site study of elevational treeline dynamics during the period 1915 to 2007 in the Swedish Scandes. The purpose is to give a concrete face of the landscape transformation which is associated with the recorded treeline shifts. The main focus is on stand-level structure of past and present treelines and the advance zones, where climate change elicited responses by Betula pubescens ssp. czerepanovii, Picea abies and Pinus sylvestris. All species shifted their treelines upslope by a maximum of c. 200 m in elevation. Most sites, however, manifested changes of smaller magnitudes. This relates to topoclimatic constraints which decouple treeline performance from the macroclimate. The general character of sites which support large and small treeline shifts, respectively, are outlined. The spacing, age structure, growth rates of the tree advance zones are accounted for each of the concerned species. In temporal and spatial detail, the different tree species responded individualistically according to their specific ecologies. Current spread of young seedlings and saplings to increasingly higher elevations in the alpine tundra is particularly highlighted as it may represent the forefront of future treeline advance. It is argued that the current evolution of the treeline ecotone represents a fundamental, although not necessarily entirely unique, reversal of the long-term (Holocene trend of neoglacial treeline descent.

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

    Directory of Open Access Journals (Sweden)

    Fansuo Zeng

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

  12. Surface pollen and its relationship to vegetation on the southern slope of the eastern Qilian Mountains%东祁连山南坡现代花粉雨与植被

    Institute of Scientific and Technical Information of China (English)

    吕新苗; 陈辉; 许清海

    2006-01-01

    The objective of this study is to investigate pollen-vegetation relationship in the Qilian Mountains. The eastern Qilian Mountains are located in the transitional zone of the Tibetan Plateau, the Loess Plateau and the arid region of Northwest China, which is one of the key areas of global environmental change. A total of 13 surface pollen samples from main vegetation have been collected.Pollen percentages were calculated in all samples. In order to reveal the relationship between pollen composition and the vegetation types from which the soil samples have been collected, Detrended Correspondence Analysis (DCA) ordination method was employed on the pollen data. The results show that dominating vegetation types can be recognized by their pollen spectra: Picea crassifolia forest, alpine shrub and alpine meadow as well. Altitude and temperature determine the distribution of the surface pollen and the vegetation. The good agreement between modern vegetation and surface samples across this area provides a measure of the reliability of using pollen data to reconstruct paleoenvironment and paleovegetation patterns in this or other similar regions. However the loss of Betula pollen in forest needs further investigation. Pollen oxidation is the most important factor contributing to the damage of modern pollen in the study area. Pollen concentrations decrease with the increase of pH values of soils, and decrease sharply when the pH exceeds 7.6.

  13. A unique Middle Pleistocene beech (Fagus)-rich deciduous broad-leaved forest in the Yangtze Delta Plain, East China: Its climatic and stratigraphic implication

    Science.gov (United States)

    Shu, Jun-wu; Wang, Wei-ming

    2012-08-01

    Pollen analysis of Middle Pleistocene sediments from the Yangtze Delta Plain provides a paleoecological reconstruction and has implications for stratigraphic correlation in East China. The pollen assemblage is characterized by high values of Fagus (16.8% on average), which is unusual because Fagus is generally present only sporadically in other lowland Quaternary pollen records from the region. In addition to Fagus, the assemblage has a rich diversity of broad-leaved deciduous trees, including Quercus, Ulmus, Carpinus/Ostrya, Juglans, Betula, and Liquidambar, as well as conifers, including Pinus, Picea, Abies, Larix, and Tsuga. Thus, the pollen flora suggests a broad-leaved deciduous forest mixed with abundant conifers, which developed under cooler and more humid conditions than present. The stable pollen sequence throughout the studied section suggests a stable environment. Beech forests also characterize the Middle Pleistocene of Taiwan and Japan, and thus may be a stratigraphic indicator of the Middle Pleistocene in East Asia. The Yangtze Delta Plain may have been an important refugium for the last survival of Fagus in the lowlands.

  14. Tracing the origin of Arctic driftwood

    Science.gov (United States)

    Hellmann, Lena; Tegel, Willy; Eggertsson, Ã.`Lafur; Schweingruber, Fritz Hans; Blanchette, Robert; Kirdyanov, Alexander; GäRtner, Holger; Büntgen, Ulf

    2013-03-01

    Arctic environments, where surface temperatures increase and sea ice cover and permafrost depth decrease, are very sensitive to even slight climatic variations. Placing recent environmental change of the high-northern latitudes in a long-term context is, however, complicated by too short meteorological observations and too few proxy records. Driftwood may represent a unique cross-disciplinary archive at the interface of marine and terrestrial processes. Here, we introduce 1445 driftwood remains from coastal East Greenland and Svalbard. Macroscopy and microscopy were applied for wood anatomical classification; a multi-species subset was used for detecting fungi; and information on boreal vegetation patterns, circumpolar river systems, and ocean current dynamics was reviewed and evaluated. Four conifer (Pinus, Larix, Picea, and Abies) and three deciduous (Populus, Salix, and Betula) genera were differentiated. Species-specific identification also separated Pinus sylvestris and Pinus sibirica, which account for ~40% of all driftwood and predominantly originate from western and central Siberia. Larch and spruce from Siberia or North America represents ~26% and ~18% of all materials, respectively. Fungal colonization caused different levels of driftwood staining and/or decay. Our results demonstrate the importance of combining wood anatomical knowledge with insight on boreal forest composition for successfully tracing the origin of Arctic driftwood. To ultimately reconstruct spatiotemporal variations in ocean currents, and to better quantify postglacial uplift rates, we recommend consideration of dendrochronologically dated material from many more circumpolar sites.

  15. Differential anatomical responses to elevated CO2 in saplings of four hardwood species.

    Science.gov (United States)

    Watanabe, Yoko; Satomura, Takami; Sasa, Kaichiro; Funada, Ryo; Koike, Takayoshi

    2010-07-01

    To determine whether an elevated carbon dioxide concentration ([CO(2)]) can induce changes in the wood structure and stem radial growth in forest trees, we investigated the anatomical features of conduit cells and cambial activity in 4-year-old saplings of four deciduous broadleaved tree species - two ring-porous (Quercus mongolica and Kalopanax septemlobus) and two diffuse-porous species (Betula maximowicziana and Acer mono) - grown for three growing seasons in a free-air CO(2) enrichment system. Elevated [CO(2)] had no effects on vessels, growth and physiological traits of Q. mongolica, whereas tree height, photosynthesis and vessel area tended to increase in K. septemlobus. No effects of [CO(2)] on growth, physiological traits and vessels were seen in the two diffuse-porous woods. Elevated [CO(2)] increased larger vessels in all species, except B. maximowicziana and number of cambial cells in two ring-porous species. Our results showed that the vessel anatomy and radial stem growth of Q. mongolica, B. maximowicziana and A. mono were not affected by elevated [CO(2)], although vessel size frequency and cambial activity in Q. mongolica were altered. In contrast, changes in vessel anatomy and cambial activity were induced by elevated [CO(2)] in K. septemlobus. The different responses to elevated [CO(2)] suggest that the sensitivity of forest trees to CO(2) is species dependent.

  16. Holocene peatland shifts in vegetation, carbon, and climate at Imnavait, Alaska

    Science.gov (United States)

    Peteet, D. M.; Nichols, J. E.; Ouni, S.; Pavia, F.; Pearl, Y.

    2012-12-01

    The Imnavait Creek basin (68 40'N, 149 20'W; elevation 875-945 m) in the foothills of the Brooks Range, AK has been well studied in terms of modern vegetational communities, hydrology, and soils. But paleoclimate and paleovegetation reconstructions are limited. We retrieved a 2-m peatland core to examine the macrofossil/biomarker/carbon sequestration history throughout the Holocene and late-glacial. AMS 14C dates of the macrofossil remains will allow us to calculate carbon sequestration rates. The Holocene history (the top meter) records marked shifts in vascular plant as well as bryophyte history. A tri-partite sequence is apparent, with Andromeda/Sphagnum remains abundant in the early Holocene. The absence of bryophytes and the presence of Eriophorum and Carex achenes characterize the mid-Holocene. Andromeda and Betula nana with Sphagnum remains are abundant in the upper 30 cm of the core. Hydrogen isotope ratios of leaf wax alkanes record higher effective moisture in the early and late Holocene, suggesting more evaporative loss in the mid-Holocene which is characterized by Eriophorum. We compare our results with previously observed palynological shifts from lakes in the region and place this Arctic paleorecord in a larger perspective of peatland histories in a N-S transect covering nearly 10 degrees of latitude across Alaska. This tripartite pattern of effective moisture appears to be the same throughout the Alaskan transect, suggesting strong climatic control.

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

    Science.gov (United States)

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

    2011-01-01

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

  18. 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.

  19. Biomass Accumulation and Net Primary Production during the Early Stage of Secondary Succession after a Severe Forest Disturbance in Northern Japan

    Directory of Open Access Journals (Sweden)

    Tomotsugu Yazaki

    2016-11-01

    Full Text Available Quantitative evaluations of biomass accumulation after disturbances in forests are crucially important for elucidating and predicting forest carbon dynamics in order to understand the carbon sink/source activities. During early secondary succession, understory vegetation often affects sapling growth. However, reports on biomass recovery in naturally-regenerating sites are limited in Japan. Therefore, we traced annual or biennial changes in plant species, biomass, and net primary production (NPP in a naturally regenerating site in Japan after windthrow and salvage-logging plantation for nine years. The catastrophic disturbance depleted the aboveground biomass (AGB from 90.6 to 2.7 Mg·ha−1, changing understory dominant species from Dryopteris spp. to Rubus idaeus. The mean understory AGB recovered to 4.7 Mg·ha−1 in seven years with the dominant species changing to invasive Solidago gigantea. Subsequently, patches of deciduous trees (mainly Betula spp. recovered whereas the understory AGB decreased. Mean understory NPP increased to 272 g·C·m−2·year−1 within seven years after the disturbance, but decreased thereafter to 189 g·C·m−2·year−1. Total NPP stagnated despite increasing overstory NPP. The biomass accumulation is similar to that of naturally regenerating sites without increase of trees in boreal and temperate regions. Dense ground vegetation and low water and nutrient availability of the soil in the study site restrict the recovery of canopy-forming trees and eventually influence the biomass accumulation.

  20. 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

  1. Late Glacial to Holocene environmental variabilities: A new multi-proxy paleolimnological study of sedimentary sequences from Como (northern Italy)

    Science.gov (United States)

    Höbig, N.; Martinelli, E.; Motella, S.; Michetti, A. M.; Livio, F.; Tinner, W.; Reicherter, K.; Castelletti, L.

    2012-04-01

    Lake Como (northern Italy) is the deepest Italian lake, reaching a depth of about 425 m. The lambda-shaped lake expands about 45 km in NE-SW direction. Southwards of the hydrologically closed western branch, two sediment cores of 70 m (S1) and 65 m length (S2) were taken in the year 2005 close to the cathedral of Como (Piazza Verdi). The drilling sites are located in the middle of the Southern Alps, some 300 m from the present-day lakeshore. The cores provide the first detailed Late Glacial to Holocene multi-proxy record for the Lake Como basin. Our research is aimed at investigating the environmental and geological evolution of the Insubria Region. The multi-proxy study of the stratigraphic sequences contain geophysical, geotechnical, sedimentological, paleobotanical, and radiocarbon analyses. They have been performed for core S1 and are still in progress on core S2. With this data the working group focuses on two main issues. The first topic is the reconstruction of the natural and anthropogenic processes controlling the ground subsidence in the Como urban area (e.g., Comerci et al., 2007) and another aim is to reconstruct vegetation and land-use dynamics. In particular, 150 samples of vegetal macroremains have been collected in the palustrine deposits along S1 core, down to 31,00 m. Below this depth (dated 14C 12,496 ± 55 yr BP - 15,050 - 14,250 cal yr BP), the amount of plant macroremains in the sediment drops dramatically. The taxonomic determination was carried out on more than 800 macroremains. They are represented by fragments of wood, leaves, needles, seeds, fruits, mosses and tiny charcoals (Motella, 2009, unpublished PhD Thesis). Picea/Larix, Pinus sp., Juniperus with Betula, found in the deeper levels (30.80 - 30.00 m), are the first arboreal taxa that colonized the shores of Lake Como, and show that the reforestation began in this area about 16,000 years ago. During the early Holocene (25.10 m) Abies alba expanded and further upwards the sequence

  2. 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

  3. 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

  4. 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

  5. Plant and mycorrhizal weathering at the laboratory mesocosm scale

    Science.gov (United States)

    Andrews, M. Y.; Leake, J.; Banwart, S. A.; Beerling, D. J.

    2011-12-01

    The evolutionary development of large vascular land plants in the Paleozoic is hypothesized to have enhanced weathering of Ca and Mg silicate minerals. This plant-centric view overlooks the fact that plants and their associated mycorrhizal fungi co-evolved. Many weathering processes usually ascribed to plants may actually be driven by the combined activities of roots and mycorrhizal fungi. This study focuses on two key evolutionary events in plant and fungal evolution: 1) the transition from gymnosperm-only to mixed angiosperm-gymnosperm forests in the Mesozoic and 2) the similarly timed rise of ectomycorrhizal fungi (EM) in a previously arbuscular mycorrhizal (AM) only world. Here we present results from a novel mesocosm-scale laboratory experiment designed to allow investigation of plant- and mycorrhizae-driven carbon fluxes and mineral weathering at different soil depths, and under ambient (400 ppm) and elevated (1500 ppm) atmospheric CO2. To test our hypothesis that photosynthetic carbon flux from the plant to the roots and fungal partner drives biological weathering of minerals, we studied five mycorrhizal plant species: the gymnosperms Sequoia sempervirens (AM), Pinus sylvestris (EM) and Ginkgo biloba (AM), and two angiosperms, Magnolia grandiflora (AM) and Betula pendula (EM). This long term (7-9 months) experiment was grown in controlled environment chambers, with replicated systems at two atmospheric CO2 levels. Each mycorrhizal plant had access to isolated horizontal mesh cores containing crushed granite and basalt at three depths, in a compost:sand (50:50 vol:vol) bulk substrate, with appropriate plant-free and mineral-free controls. 14CO2 pulse-labeling provided a snapshot of the magnitude, timing, and allocation of carbon through the atmosphere-plant-fungi-soil system and also measured mycorrhizal fungal activity associated with the target granite and basalt. Total plant and fungal biomass were also assessed in relation to +/- mineral treatments and

  6. 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)

  7. 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

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

    Science.gov (United States)

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

    2009-12-01

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

  9. 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

  10. 开花调控基因BpMADS4无抗性表达载体的构建%Construction of Non-resistance Plant Expression Vector of Flowering Regulatory Gene BpMADS4

    Institute of Scientific and Technical Information of China (English)

    李玉生; 吴永杰; 赵艳华; 吴雅琴; 程和禾; 陈龙

    2012-01-01

    为了构建含有报告基因GFP基因和BpMADS4基因的无抗性双元表达载体pCAMBIA1302-GFP-Bp,参考已发表的欧洲白桦(Betula pendula)开花调控基因(BpMADS4)序列,利用逆转录-聚合酶链式反应(RT-PCR)从欧洲白桦的幼嫩花序中克隆得到促进开花的BpMADS4基因。将该基因替换pCAMBIA1302载体中的潮霉素抗性基因,构建含有报告基因GFP基因和BpMADS4基因的无抗性双元表达载体pCAM-BIA1302-GFP-Bp。结果表明:成功构建了无抗性双元表达载体pCAMBIA1302-GFP-Bp。该表达载体在苹果遗传转化中不使用抗生素筛选,可以解决抗生素抗性筛选降低苹果转基因转化效率的问题以及转基因苹果中选择标记基因造成的生物安全性问题,用该载体转化苹果可以缩短苹果童期,有效提高其育种效率。本研究为筛选对环境安全的、具有易成花特性的苹果新种质奠定了基础。%To construct the non-resistance plant binary expression vector pCAMBIA1302-GFP-Bp containing GFP and BpMADS4 genes, according to the published flowering regulatory gene (BpMADS4) sequence of Betula pendula, we obtained BpMADS4 gene from the young inflorescence of B. pendula by RT-PCR method. The tide amphotericin resistance gene in pCAMBIA1302 vector was replaced by BpMADS4 gene. The results showed that PCR identification, restriction enzyme digestion and sequence analysis confirmed the non-resistance plant binary expression vector pCAMBIA1302-GFP-Bp was successfully constructed. Using pCAMBIA1302-GFP-Bp vector, antibiotic was not used in genetic transformation of apple. Some problems such as antibiotic resistance screening reducing the efficiency of apple transformation, and biological safety problems caused by using select marker genes in transgenie apple could be resolved. Transforming pCAMBIA1302-GFP-Bp vector into apple could shorten the juvenile stage, and effectively improve the breeding efficiency. This laid a foundation for

  11. Modeling the impact of disturbances on the carbon cycle of a mixed-deciduous forest in the upper Midwest

    Science.gov (United States)

    Frasson, R.; Bohrer, G.; Medvigy, D.; Ivanov, V. Y.; Vogel, C.; Curtis, P.

    2013-12-01

    Disturbances, either natural or anthropogenic, impact the carbon and water cycles. Therefore, understanding their immediate effect, as well as how fluxes evolve while forests recover from disturbances is essential to carbon and water cycle modeling. Our study area is located in northern Michigan and encompasses the mixed-deciduous forest surrounding the University of Michigan Biological Station (UMBS). The two AmeriFlux affiliated towers operated by the UMBS, one with an undisturbed footprint and a second overlooking the Forest Accelerated Succession ExperimenT (FASET) site, a 39 ha area where all aspen (Populus spp.) and birch (Betula papyrifera) trees were girdled, provides the supporting data for our study. We used the Ecosystem Demography model version 2 (ED2) to run three scenarios: a control (undisturbed) case, a homogeneous disturbance (dist-1) where 30% of the leaf area was removed regardless of functional type, and a FASET like disturbance (dist-2) where all early successional trees, which occupy 30% of leaf area, were removed. We parameterized ED2 using observations of monthly and yearly net ecosystem exchange (NEE), latent, and sensible heat fluxes from the undisturbed site (UMBS-AmeriFlux) from pre-disturbance years. We force the model using meteorological data recorded by the flux towers and evaluate the output of the three cases against NEE, latent, and sensible heat fluxes measured at the UMBS-AmeriFlux site (undisturbed case) and against the FASET tower (cases dist-1 and dist-2) after the disturbance occurred. Our results indicate that in such a case of an intermediate disturbance the results of the disturbance are defendant on the functional type that was affected. As a result of this study, we expect to improve the understanding of the role disturbances and the subsequent recovery on carbon and water fluxes of broadleaved deciduous forests.

  12. Young infants with atopic dermatitis can display sensitization to Cor a 9, an 11S legumin-like seed-storage protein from hazelnut (Corylus avellana).

    Science.gov (United States)

    Verweij, Marjoke M; Hagendorens, Margo M; De Knop, Kathleen J; Bridts, Chris H; De Clerck, Luc S; Stevens, Wim J; Ebo, Didier G

    2011-03-01

    Allergy to hazelnut (Corylus avellana) can be severe and occur at young age. Atopic dermatitis (AD) can involve sensitization to various foods. The objective is to investigate the pattern of hazelnut sensitization in infants with AD. Sera of 34 infants all under 1 year of age and suffering from AD were selected according to prior specific IgE results. Twenty-nine infants were sensitized to traditional food allergens, five were not. From the 29 infants with a sensitization to at least one food allergen, 20 demonstrated IgE reactivity to hazelnut. All sera were analyzed with the allergen microarray immunoassay (ImmunoCAP ISAC). Twelve (60%) of the children with IgE reactivity to hazelnut demonstrated sensitization to Cor a 9, the 11S legumin-like seed-storage protein from hazelnut. In these infants, no sensitization to Cor a 1, the homologue of the major birch pollen allergen Bet v 1 (Betula verrucosa), or the lipid transfer protein (Cor a 8) from hazelnut was demonstrable. Half of the children sensitized to Cor a 9 demonstrated IgE reactivity to its homologue in peanut (Arachis hypogaea; Ara h 3) from which five were also sensitized to Gly m 6 from soy (Glycine max). None of the infants with AD without IgE reactivity to hazelnut demonstrated sensitization to Cor a 1, 8, or 9. In conclusion, young infants with atopic dermatitis sensitized to hazelnut can already display IgE reactivity to Cor a 9, a potentially dangerous hazelnut component. The mechanism(s) of this early sensitization and its clinical significance remain elusive.

  13. Hazelnut (Corylus avellana) vicilin Cor a 11: molecular characterization of a glycoprotein and its allergenic activity.

    Science.gov (United States)

    Lauer, Iris; Foetisch, Kay; Kolarich, Daniel; Ballmer-Weber, Barb