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Sample records for beech trees

  1. Alterations in the nitrogen dynamics of European beech trees infested by the woolly beech aphid

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    Levia, D. F.; Michalzik, B.

    2012-12-01

    Insects are a major stressor in wooded ecosystems, triggering profound changes in the hydrology, biogeochemistry, and net primary productivity of infested forests. The influence of woolly beech aphids (Phyllaphis fagi L.) on nitrogen cycling via throughfall, stemflow, and litter leachates is not well understood. Employing a combination of field sampling, X-ray photoelectron spectroscopy, and scanning electron microscopy, we examined and compared the alterations and partitioning of nitrogen (particulate, dissolved, organic, inorganic) between control (uninfested) and infested trees. Preliminary results suggest that the amount of nitrogen routed to the soil is much lower in throughfall and stemflow of infested trees than control trees. Preliminary X-ray photoelectron spectroscopy and scanning electron microscopy measurements on the abaxial surface of sample leaves have demonstrated that the surface microbiology and nitrogen chemistry of control, lightly infested, and heavily infested leaves are notably different. These observations suggest that the aphids alter the phyllosphere ecology to such an extent that they trigger nitrogen uptake by microbes on the leaf surface in the presence of easily available carbon from aphid excretions (i.e., honeydew). A better understanding of nitrogen cycling in stressed forests would advance theories of nitrogen cycling.

  2. Pointer years in the growth of beech trees of the NP "Đerdap" area

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    Stajić Branko

    2014-01-01

    Full Text Available This paper defines pointer years and years with distinctive tree rings in the growth of beech in 3 sites (ecological units-EU of the area of Đerdap, in order to observe the reactions of trees to the effects of various factors of growth. The pointer years were determined by the Schweingruber (1983 methodology. The years with distintive tree rings were defined as the years of beech growth with very pronounced distinctive growth rings (annual ring width at least ± 2 standard deviations higher or lower than the arithmetic mean and pronounced typical growth rings (annual ring width at least ± 1.5 standard deviation higher or lower than the arithmetic mean. The common pointer years for the growth of beech in the site conditions of all three ecological units are 1977 and 1988 (negative pointer years. A particular pointer year is 1988, when in more than 90% of trees under the analyzed environmental conditions the marked reduction of tree rings width of the trees (EUB or very pronounced reduction in the width of tree rings (EUA and ESV were observed. [Projekat Ministarstva nauke Republike Srbije, br. 43007: Istraživanje klimatskih promena na životnu sredinu: praćenje uticaja, adaptacija i ublažavanje

  3. Attitudes of ornamental trees and shrubs producers towards nursery production of ornamental beech cultivars in Serbia

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    Nonić Marina

    2016-01-01

    Full Text Available European beech (Fagus sylvatica L. is, along with its significance as a forest species, renowned as an ornamental species, due to its numerous cultivars. Ornamental beech cultivars are planted in various green spaces, but a small number of such trees have ascertained in Serbia. For the time being, production of beech cultivars is represented in a very small number of nurseries, with a negligible share of those seedlings in their total assortment. The aim of this research is to study the attitudes of ornamental trees and shrubs producers towards the nursery production of ornamental beech cultivars, and possibilities of its improvements in Serbia. “Door to door” survey and in-depth interviews were used as research techniques. Surveys with the representatives of 65 nurseries in Serbia (in the selected statistical region Šumadija and Western Serbia were conducted in the first stage of data collection. In the second stage of data collection were interviewed the representatives of the 10 nurseries who, during the survey, pointed out that they produce ornamental beech cultivars. Nurserymen’s attitudes suggest that there is a possibility to improve the production of ornamental beech cultivars in Serbia, with the appropriate support measures and increased interest of customers on the market, i.e. with the provision of subsidies for the production of seedlings and greater use of cultivars by utility companies in the cities of Serbia. [Projekat Ministarstva nauke Republike Srbije, br. ТP 31041: Establishment of forest plantations to increase the afforested areas in Serbia

  4. Factors impacting stemflow generation in a European beech forest: Individual tree versus neighborhood properties

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    Metzger, Johanna Clara; Germer, Sonja; Hildebrandt, Anke

    2017-04-01

    The redistribution of precipitation by canopies changes the water flow dynamics to the forest floor. The spatial pattern of throughfall has been researched in a number of studies in different ecosystems. Yet, also stemflow substantially influences water input patterns, constituting a mean of 12% of gross precipitation for European beech as one of the most abundant tree species in Central Europe. While the initiation of stemflow depends mostly on precipitation event properties, stemflow amounts are strongly shaped by canopy structure. Stemflow research has mainly addressed the impact of single tree morphological variables. In previous studies, the impact of forest structure on area-based stemflow was studied comparing plots with different properties using few exemplary stemflow measurements. In non-homogeneous stands, this approach might not be accurate, as the variation of stand properties like tree density could change tree individual stemflow fluxes. To investigate this, a total measurement of all trees per plot is required. We hypothesize, that in addition to individual tree metrics, tree neighborhood relations have a significant impact on stemflow generation in a heterogeneous beech forest. Our study site is located in the pristine forest of the National Park Hainich, central Germany. It is heterogeneous in respect to tree density, species composition and tree age. We measured stemflow in an areal approach, for all trees on 11 subplots (each 10 m x 10 m) spaced evenly throughout a 1 ha plot. This involved overall 65 trees, which is 11% of the plot's trees. 27 precipitation events were recorded in spring and early summer of 2015 and 2016. Stand properties were surveyed, including diameter at breast height, height, position and species of a tree. From this data, we calculated neighborhood properties for each tree, as number, basal area, and relative height of neighboring trees within a radius of the plot's mean tree distance. Using linear mixed effects models, we

  5. Proximate content and lipid profile of seeds from Rapanea melanophloeos (The Cape Beech) tree

    International Nuclear Information System (INIS)

    Lotier, N.; Chivandi, E.; Lembede, B.W.; Ibrahim, K.G.; Nyakudya, T.T.

    2017-01-01

    Rapanea melanophloeos(Cape beech)is a fruit-bearing tree indigenous to Southern Africa which produces edible fruit. Seed samples obtained from ripe fruit of the Cape beech trees had their proximate analysis and lipid profiling done. The dry matter and ash contributed 91.29 +- 0.00 %, 1.50 +- 0.01 % of the mass of the seed. Whilst the other proximate analytes namely crude fibre, crude protein and ether extract made up 5.71 +- 0.43 %, 10.50 +- 0.49 % and 4.75 +- 0.09 percentage of the mass of the seeds respectively. The fatty acid profile of the seed oil revealed Linoleic acid (50.43 +- 0.38 %) to be the most dominant. R. melanophloeos seeds are not a viable source of nutrients. (author)

  6. Variability of European beech wood density as influenced by interactions between tree-ring growth and aspect

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    Daniela Diaconu

    2016-02-01

    Full Text Available Background: Wood density is considered to be the most important predictor of wood quality but despite its importance, diffuse-porous tree species have been the subject of only a limited number of studies. The importance of European beech forests for Central Europe calls for profound research to examine the potential impact of a warmer climate on the quality of beech timber. Methods: In this study we analysed the influence of tree-ring width and tree-ring age on the wood density of beech, and whether the wood density response to these two parameters is modified by aspect. A linear mixed-effects model for wood density was constructed for mean density data measured with high frequency densitometry on stem discs from 72 beech trees sampled from two different aspects (northeast -NE and southwest -SW of a valley in southwestern Germany. Results: Part of the variability of mean annual wood density was explained by cambial age: an increase in cambial age resulted in an increase in mean wood density. Tree-ring width and aspect had only a small influence on wood density. Wood density on the SW aspect was lower than on the NE with a difference of approximately 0.006 g/cm3. The between-tree variability was very high. Conclusions: The significant interaction between cambial age and aspect reflects the importance of site conditions at older tree ages: with increasing cambial age the difference between aspects becomes stronger. Our results give a better understanding of the importance of site conditions on the wood quality of beech. Keywords: Fagus sylvatica, HF densitometry, Wood quality, Wood density, Aspect

  7. Tree and stand growth of mature Norway spruce and European beech under long-term ozone fumigation

    International Nuclear Information System (INIS)

    Pretzsch, Hans; Dieler, Jochen; Matyssek, Rainer; Wipfler, Philip

    2010-01-01

    In a 50- to 70-year-old mixed stand of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) in Germany, tree cohorts have been exposed to double ambient ozone (2xO 3 ) from 2000 through 2007 and can be compared with trees in the same stand under the ambient ozone regime (1xO 3 ). Annual diameter growth, allocation pattern, stem form, and stem volume were quantified at the individual tree and stand level. Ozone fumigation induced a shift in the resource allocation into height growth at the expense of diameter growth. This change in allometry leads to rather cone-shaped stem forms and reduced stem stability in the case of spruce, and even neiloidal stem shapes in the case of beech. Neglect of such ozone-induced changes in stem shape may lead to a flawed estimation of volume growth. On the stand level, 2xO 3 caused, on average, a decrease of 10.2 m 3 ha -1 yr -1 in European beech. - Ozone effects on tree growth and stem shape were investigated for Norway spruce and European beech; the study reveals species-specific reaction patterns in growth rate and allometry under ozone exposure.

  8. Tree and stand growth of mature Norway spruce and European beech under long-term ozone fumigation

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    Pretzsch, Hans, E-mail: h.pretzsch@lrz.tum.d [Chair for Forest Growth and Yield Science, Technische Universitaet Muenchen, Am Hochanger 13, D-85354 Freising (Germany); Dieler, Jochen [Chair for Forest Growth and Yield Science, Technische Universitaet Muenchen, Am Hochanger 13, D-85354 Freising (Germany); Matyssek, Rainer [Chair for Ecophysiology of Plants, Technische Universitaet Muenchen, Am Hochanger 13, D-85354 Freising (Germany); Wipfler, Philip [Chair for Forest Growth and Yield Science, Technische Universitaet Muenchen, Am Hochanger 13, D-85354 Freising (Germany)

    2010-04-15

    In a 50- to 70-year-old mixed stand of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) in Germany, tree cohorts have been exposed to double ambient ozone (2xO{sub 3}) from 2000 through 2007 and can be compared with trees in the same stand under the ambient ozone regime (1xO{sub 3}). Annual diameter growth, allocation pattern, stem form, and stem volume were quantified at the individual tree and stand level. Ozone fumigation induced a shift in the resource allocation into height growth at the expense of diameter growth. This change in allometry leads to rather cone-shaped stem forms and reduced stem stability in the case of spruce, and even neiloidal stem shapes in the case of beech. Neglect of such ozone-induced changes in stem shape may lead to a flawed estimation of volume growth. On the stand level, 2xO{sub 3} caused, on average, a decrease of 10.2 m{sup 3} ha{sup -1} yr{sup -1} in European beech. - Ozone effects on tree growth and stem shape were investigated for Norway spruce and European beech; the study reveals species-specific reaction patterns in growth rate and allometry under ozone exposure.

  9. Bark vegetation contributes to nitrous oxide (N2O) deposition by mature beech trees

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    Machacova, Katerina; Maier, Martin; Svobodova, Katerina; Lang, Friederike; Urban, Otmar

    2017-04-01

    Nitrous oxide (N2O) contributes to the acceleration of the greenhouse effect. Accordingly, there is an urgent need to investigate the natural capability of forest ecosystems to exchange N2O with the atmosphere. While the soils of temperate forests were shown to be a significant natural source of N2O, trees have been so far overlooked in the forest N2O inventories. Trees are known, however, to emit this gas, especially at very high N2O concentration in soil. We determined the N2O fluxes in mature beech trees (Fagus sylvatica) in two upland mountain forests (White Carpathians, CZ; Black Forest, DE) with predominant soil N2O uptake. To understand these fluxes, N2O exchange in photoautotrophic organisms associated with beech stems (lichens, mosses, and algae) was further investigated under laboratory conditions. Fluxes were measured in situ in June and July 2015 using static chamber systems followed by chromatographic and photo-acoustic analyses of N2O concentration changes. In both forests studied, all beech stems deposited N2O from the atmosphere. Such consistent uptake of N2O by stems represents a novel and unique finding which is in the contrast to current limited studies presenting trees as N2O emitters. The mean stem deposition rates were significantly higher in the White Carpathians (-3.8 μg N2O m-2 stem area h-1) than in the Black Forest (-2.3 μg N2O m-2 h-1). The forest floor was a strong sink for N2O (White Carpathians: -111, Black Forest: -81 μg N2O m-2 soil area h-1). The N2O concentration profiles within the soil did not identify any apparent production or consumption processes. Photoautotrophic organisms (lichens, mosses, and algae), largely associated with the bark of studied trees, were collected for further analyses. The detailed incubation experiments revealed that all sampled organisms deposited N2O under the conditions of full rehydration and air temperature of 25˚ C. Their deposition rates per unit area were in the same order of magnitude as

  10. The neglected bee trees: European beech forests as a home for feral honey bee colonies

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    Patrick Laurenz Kohl

    2018-04-01

    Full Text Available It is a common belief that feral honey bee colonies (Apis mellifera L. were eradicated in Europe through the loss of habitats, domestication by man and spread of pathogens and parasites. Interestingly, no scientific data are available, neither about the past nor the present status of naturally nesting honeybee colonies. We expected near-natural beech (Fagus sylvatica L. forests to provide enough suitable nest sites to be a home for feral honey bee colonies in Europe. Here, we made a first assessment of their occurrence and density in two German woodland areas based on two methods, the tracing of nest sites based on forager flight routes (beelining technique, and the direct inspection of potential cavity trees. Further, we established experimental swarms at forest edges and decoded dances for nest sites performed by scout bees in order to study how far swarms from beekeeper-managed hives would potentially move into a forest. We found that feral honey bee colonies regularly inhabit tree cavities in near-natural beech forests at densities of at least 0.11–0.14 colonies/km2. Colonies were not confined to the forest edges; they were also living deep inside the forests. We estimated a median distance of 2,600 m from the bee trees to the next apiaries, while scout bees in experimental swarms communicated nest sites in close distances (median: 470 m. We extrapolate that there are several thousand feral honey bee colonies in German woodlands. These have to be taken in account when assessing the role of forest areas in providing pollination services to the surrounding land, and their occurrence has implications for the species’ perception among researchers, beekeepers and conservationists. This study provides a starting point for investigating the life-histories and the ecological interactions of honey bees in temperate European forest environments.

  11. Battling beech bark disease: establishment of beech seed orchards in Michigan

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    Jennifer L. Koch; Robert L. Heyd

    2013-01-01

    Amidst the dead, dying, and deformed beech trees left in the wake of beech bark disease (BBD), we are fortunate to find beech trees that remain healthy even in heavily infested areas. In stands across several US states it has been reported that disease-free beech trees are often found in clusters, providing evidence that resistance could be a genetic trait. Trees...

  12. Transcriptional signatures in leaves of adult European beech trees (Fagus sylvatica L.) in an experimentally enhanced free air ozone setting

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    Olbrich, Maren, E-mail: maren.olbrich@helmholtz-muenchen.d [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany); Gerstner, Elke; Bahnweg, Guenther [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany); Haeberle, Karl-Heinz; Matyssek, Rainer [Technische Universitaet Muenchen, Ecophysiology of Plants, Am Hochanger 13, 85354 Freising (Germany); Welzl, Gerhard [Institute of Developmental Genetics, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany); Heller, Werner; Ernst, Dieter [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, 85764 Neuherberg (Germany)

    2010-04-15

    Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavaria). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two other transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. - At the transcriptional level, leaves of mature beech trees barely react to double ambient ozone concentrations; differences are detected primarily between sun/shade leaves and between different growing seasons.

  13. Transcriptional signatures in leaves of adult European beech trees (Fagus sylvatica L.) in an experimentally enhanced free air ozone setting

    International Nuclear Information System (INIS)

    Olbrich, Maren; Gerstner, Elke; Bahnweg, Guenther; Haeberle, Karl-Heinz; Matyssek, Rainer; Welzl, Gerhard; Heller, Werner; Ernst, Dieter

    2010-01-01

    Tropospheric ozone causes severe oxidative stress in plants. To investigate the transcriptional responsiveness of adult trees to ozone, fully-expanded sun and shade leaves of mature beech trees were harvested at four time points over the entire vegetation period in 2005 and 2006. Microarray analyses were conducted on leaves from trees grown in the field under ambient and twice-ambient ozone concentrations at Kranzberger Forst (Bavaria). Beech trees changed their transcript levels in response to ozone. In the years 2005 and 2006 different transcription patterns were observed; this may have been a result of different weather conditions and ozone uptake. Furthermore, we obtained differences in mRNA expression patterns between shade and sun leaves. In the ozone-treated sun leaves of 2005, slightly up- and down-regulated transcript levels were detected, particularly in the spring and autumn, whereas shade leaves clearly exhibited reduced mRNA levels, particularly at the end of the vegetation period. In 2006, this pattern could not be confirmed, and in the autumn, four other transcripts were slightly up-regulated in ozone-treated shade leaves. In addition, two other transcripts were found to be influenced in sun leaves in the spring/summer. While we detected changes in the levels of only a few transcripts, the observed effects were not identical in both years. In conclusion, elevated ozone exhibited very small influence on the transcription levels of genes of mature beech trees. - At the transcriptional level, leaves of mature beech trees barely react to double ambient ozone concentrations; differences are detected primarily between sun/shade leaves and between different growing seasons.

  14. Tree- and Stand-Level Thinning Effects on Growth of European Beech (Fagus sylvatica L. on a Northeast- and a Southwest-Facing Slope in Southwest Germany

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    Daniela Diaconu

    2015-09-01

    Full Text Available Anticipated changes in climate and research findings on the drought sensitivity of beech have triggered controversial discussions about the future of European beech. We investigated the growth response of beech on the tree- and stand-level in mature stands to three different thinning intensities (no thinning, strong thinning, very strong thinning on a northeast- and southwest-facing slope in Southwest Germany. Linear mixed-effects models were formulated to describe effects on growth parameters on the tree- and stand-level (diameter, height, basal area, volume. At the stand-level, the stand basal area increment and stand volume increment were lower on the thinned plots. At the tree-level, the basal area increment significantly increased with increasing thinning intensity. The growth of individual trees was also influenced by initial tree size, the size-related rank of the tree within a stand, and by the aspect of the site. Our data indicate that growth of European beech is impaired on the southwest-facing slope with a warmer and drier climate and that a very strong thinning regime applied at advanced age can accelerate growth of European beech trees even on the warmer and drier site. Our findings, therefore, imply that in a warmer climate intensive thinning may also represent an important adaptive forest management measure in European beech stands.

  15. Armillaria mellea and mortality of beech affected by beech bark disease

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    Philip M. Wargo

    1983-01-01

    The role of Armillaria mellea in the mortality of beech trees affected by beech bark disease was determined by excavating root systems of beech trees infested by beech scale, Cryptococcus fagisuga, or also infected by the bark fungus, Nectria coccinea var. faginata. Only trees infected by

  16. THE ROLE OF TREEFALL COMPLEXES IN REGENERATION OF TREE SPECIES AND IN MAINTAINING OF BIOLOGICAL DIVERSITY OF NATURAL BEECH AND DARK CONIFEROUS-BEECH FORESTS OF THE UKRAINIAN CARPATHIANS

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    S. I. Ripa

    2017-06-01

    Full Text Available Understanding of maintaining biological diversity mechanisms is important for elaborating methods for the restoration of natural forests that most fully implement ecosystem functions. The objectives of work are: to identify intact beech and dark coniferous-beech forests of the Carpathians on the basis of analyzing history of nature management and field studies; to characterize the population structure of the main tree species in the intact forests of the Carpathians; to determine the renewal of various species of trees, shrubs, herbs and bryophytes to treefall microsites in the forest types studied. The objects of the research are monodominant beech forests and mixed (dark coniferous-beech forests of the Ukrainian Carpathians, in which beech (Fagus sylvatica, white fir (Abies alba and European spruce (Picea abies are the main dominant of tree sinusia. Monodominant beech forests (the age of stands 250–350 years were studied on 9 sample plots (from 1 to 1.05 ha laid in the Ugolsky forest range of the Carpathian Biosphere Reserve at an altitude of 600 to 1000 m above sea level, and also on the 2 sample plots (from 1 to 1.09 hectares laid in the Lower Volovets forestry at an altitude of 600–800 meters above sea level. Uneven-aged dark coniferous-beech forest (the age of forest stands is 250–300 years old was explored on one sample plot (1.2 ha laid in the Podlisnivsky forestry of the Carpathian National Park at an altitude of 750 m above sea level. Population analysis of the main tree and shrub species as well as geobotanical releves was made on the sample plots. Treefall microsite complexes were investigated to identify the peculiarities in the location of tree undergrowth, herb and moss species in beech and mixed forests. The following elements of treefall microsite complex were singled out: treefall pit, treefall mound and tree trunk. At each treefall microsite complex the research was carried out according to the following scheme: an

  17. Modelling individual tree height to crown base of Norway spruce (Picea abies (L. Karst. and European beech (Fagus sylvatica L..

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    Ram P Sharma

    Full Text Available Height to crown base (HCB of a tree is an important variable often included as a predictor in various forest models that serve as the fundamental tools for decision-making in forestry. We developed spatially explicit and spatially inexplicit mixed-effects HCB models using measurements from a total 19,404 trees of Norway spruce (Picea abies (L. Karst. and European beech (Fagus sylvatica L. on the permanent sample plots that are located across the Czech Republic. Variables describing site quality, stand density or competition, and species mixing effects were included into the HCB model with use of dominant height (HDOM, basal area of trees larger in diameters than a subject tree (BAL- spatially inexplicit measure or Hegyi's competition index (HCI-spatially explicit measure, and basal area proportion of a species of interest (BAPOR, respectively. The parameters describing sample plot-level random effects were included into the HCB model by applying the mixed-effects modelling approach. Among several functional forms evaluated, the logistic function was found most suited to our data. The HCB model for Norway spruce was tested against the data originated from different inventory designs, but model for European beech was tested using partitioned dataset (a part of the main dataset. The variance heteroscedasticity in the residuals was substantially reduced through inclusion of a power variance function into the HCB model. The results showed that spatially explicit model described significantly a larger part of the HCB variations [R2adj = 0.86 (spruce, 0.85 (beech] than its spatially inexplicit counterpart [R2adj = 0.84 (spruce, 0.83 (beech]. The HCB increased with increasing competitive interactions described by tree-centered competition measure: BAL or HCI, and species mixing effects described by BAPOR. A test of the mixed-effects HCB model with the random effects estimated using at least four trees per sample plot in the validation data confirmed

  18. On the influence of provenance to soil quality enhanced stress reaction of young beech trees to summer drought.

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    Buhk, Constanze; Kämmer, Marcel; Beierkuhnlein, Carl; Jentsch, Anke; Kreyling, Jürgen; Jungkunst, Hermann F

    2016-11-01

    Climate projections propose that drought stress will become challenging for establishing trees. The magnitude of stress is dependent on tree species, provenance, and most likely also highly influenced by soil quality. European Beech ( Fagus sylvatica ) is of major ecological and economical importance in Central European forests. The species has an especially wide physiological and ecological amplitude enabling growth under various soil conditions within its distribution area in Central Europe. We studied the effects of extreme drought on beech saplings (second year) of four climatically distinct provenances growing on different soils (sandy loam and loamy sand) in a full factorial pot experiment. Foliar δ 13 C, δ 15 N, C, and N as well as above- and belowground growth parameters served as measures for stress level and plant growth. Low-quality soil enhanced the effect of drought compared with qualitatively better soil for the above- and belowground growth parameters, but foliar δ 13 C values revealed that plant stress was still remarkable in loamy soil. For beeches of one provenance, negative sandy soil effects were clearly smaller than for the others, whereas for another provenance drought effects in sandy soil were sometimes fatal. Foliar δ 15 N was correlated with plant size during the experiment. Plasticity of beech provenances in their reaction to drought versus control conditions varied clearly. Although a general trend of declining growth under control or drought conditions in sandy soil was found compared to loamy soil, the magnitude of the effect of soil quality was highly provenance specific. Provenances seemed to show adaptations not only to drought but also to soil quality. Accordingly, scientists should integrate information about climatic pre-adaptation and soil quality within the home range of populations for species distribution modeling and foresters should evaluate soil quality and climatic parameters when choosing donor populations for

  19. Root-derived carbon and nitrogen from beech and ash trees differentially fuel soil animal food webs of deciduous forests.

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    Sarah L Zieger

    Full Text Available Evidence is increasing that soil animal food webs are fueled by root-derived carbon (C and also by root-derived nitrogen (N. Functioning as link between the above- and belowground system, trees and their species identity are important drivers structuring soil animal communities. A pulse labeling experiment using 15N and 13C was conducted by exposing beech (Fagus sylvatica and ash (Fraxinus excelsior seedlings to 13CO2 enriched atmosphere and tree leaves to 15N ammonium chloride solution in a plant growth chamber under controlled conditions for 72 h. C and N fluxes into the soil animal food web of beech, associated with ectomycorrhizal fungi (EMF, and ash, associated with arbuscular mycorrhizal fungi (AMF, were investigated at two sampling dates (5 and 20 days after labeling. All of the soil animal taxa studied incorporated root-derived C, while root-derived N was only incorporated into certain taxa. Tree species identity strongly affected C and N incorporation with the incorporation in the beech rhizosphere generally exceeding that in the ash rhizosphere. Incorporation differed little between 5 and 20 days after labeling indicating that both C and N are incorporated quickly into soil animals and are used for tissue formation. Our results suggest that energy and nutrient fluxes in soil food webs depend on the identity of tree species with the differences being associated with different types of mycorrhiza. Further research is needed to prove the generality of these findings and to quantify the flux of plant C and N into soil food webs of forests and other terrestrial ecosystems.

  20. Drought Stress Reaction of Growth and Δ13C in Tree Rings of European Beech and Norway Spruce in Monospecific Versus Mixed Stands Along a Precipitation Gradient

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    Cynthia Schäfer

    2017-05-01

    Full Text Available Tree rings include retrospective information about the relationship between climate and growth, making it possible to predict growth reaction under changing climate. Previous studies examined species-specific reactions under different environmental conditions from the perspective of tree ring growth and 13C discrimination (Δ13C. This approach is extended to monospecific versus mixed stands in the present paper. We investigated the resistance and resilience of Norway spruce (Picea abies [L.] Karst and European beech (Fagus sylvatica [L.] in response to the drought event in 2003. The study was carried out along a precipitation gradient in southern Germany. Responses of basal area increment (BAI and Δ13C were correlated with a Climate-Vegetation-Productivity-Index (CVPI. The species showed different strategies for coping with drought stress. During the summer drought of 2003, the BAI of spruces reveal a lower resistance to drought on dry sites than those of beech. For beech, we found an increasing resistance in BAI and Δ13C from dry to moist sites. In mixture with spruce, beech had higher resistance and resilience for Δ13C with increasing site moisture. The combination of Δ13C and tree ring growth proxies improves our knowledge of species-specific and mixture-specific reactions to drought for sites with different moisture conditions.

  1. Comparison of protein profiles of beech bark disease-resistant or beech bark disease-susceptible American beech

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    Mary E. Mason; Marek Krasowski; Judy Loo; Jennifer. Koch

    2011-01-01

    Proteomic analysis of beech bark proteins from trees resistant and susceptible to beech bark disease (BBD) was conducted. Sixteen trees from eight geographically isolated stands, 10 resistant (healthy) and 6 susceptible (diseased/infested) trees, were studied. The genetic complexity of the sample unit, the sampling across a wide geographic area, and the complexity of...

  2. Beech tree analyses in the Bohemian/Austrian/Bavarian frontier region; Fallstudie Buche im Dreilaendereck Boehmen/Oberoesterreich/Bayern

    Energy Technology Data Exchange (ETDEWEB)

    Kirchner, M. [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Muenchen (Germany). Inst. fuer Oekologische Chemie; Baumgarten, M.; Matyssek, R. [Muenchen Univ., Freising (DE). Lehrstuhl fuer Forstbotanik] [and others

    2000-08-01

    The condition of beech trees was investigated in six forest stands in the Bayerischer Wald and Boehmerwald mountains between 1995 and 1997 in order to establish the interdependence between tree conditions, the prevailing natural and anthropogenic site factors, and air pollution especially with groundlevel ozone. Details of the investigations are presented. Although a potential long-term effect of ozone cannot be excluded, the damage observed in beech trees in this region since the eighties is assumed to be caused not by a single factor but by complex interaction patterns between several anthropogenic and natural factors. [German] Es erfolgte im Untersuchungsgebiet Bayerischer Wald/Boehmerwald im Zeitraum 1995 bis 1997 eine detaillierte Zustandscharakterisierung von Altbuchen an sechs Standorten. Im Rahmen der Gesamtuntersuchung sollte geklaert werden, ob Zusammenhaenge zwischen dem Baumzustand und den herrschenden natuerlichen und anthropogenen Standortfaktoren und Luftbelastungen mit Schwerpunkt des bodennahen Ozons bestehen. An Hand kontinuierlicher Ozonmessungen konnte bestaetigt werden, dass die Konzentration des bodennahen Ozons im wesentlichen eine Funktion der Meereshoehe ist; somit ist an Hochlagenstandorten von hoeheren Immissionen auszugehen. Bei den moeglicherweise besser an photooxidativen Stress akklimatisierten Hochlagenbuchen waren die Schaeden bei erhoehter Ozonbelastung geringer ausgepraegt als bei Tieflagenbuchen. Fuer die Hypothese, wonach man eine staerkere Schaedigung der Hochlagenbestaende zu erwarten hat, wurde keine Bestaetigung gefunden. Inositol wird seit einiger Zeit als sensitiver Indikator diskutiert, der auf veraenderte Umweltbedingungen reagiert. Die Inositolkonzentration in Sonnenblaettern von Altbuchen im Bayerischen Wald war in 1995 um ca. 50% geringer als in 1996. Bei den Jungbuchen im Phytotronenexperiment kam es bei anhaltendem Ozonstress und zunehmender Schaedigung zu einer starken Reduktion der Inositolkonzentration in

  3. Study of Gap-phase Regeneration in a Managed Beech Forest: Relations between Tree Regeneration and Light, Substrate Features and Cover of Ground Vegetation

    Directory of Open Access Journals (Sweden)

    MIHÓK, Barbara

    2005-01-01

    Full Text Available Gap formation by wind is a characteristic disturbance event in European beech forests. Changes in abiotic environmental variables depend on gap size and different site features. The aim of this gap-study is to test the effect of gap size on spatial distribution of abiotic environmental variables and on the abundance and distribution of tree regeneration. Eight experimental gaps – three large (d: 35-40 m and five small (d: 10-15 m – were created in a mesotrophic beech forest in winter 2000/2001. Data were collected systematically in 1m x 1m quadrats before gap creation and subsequently on five occasions. Hemispherical photographs were used to estimate relative light intensity along a gap–under-canopy transect. First results of this long-term study suggest that establishment of beech seedlings is negatively influenced by dispersal limitation in large gaps and amount of slash as well, while it seems to be insensitive to environmental conditions. Development of beech saplings is accelerated by increased light intensity, and by protective effect of dense herb layer in opened sites. Salix caprea — as a light demanding species — appears mostly in the centre of large gaps.

  4. Transformation of iron forms during pedogenesis after tree uprooting in a natural beech-dominated forest

    Czech Academy of Sciences Publication Activity Database

    Tejnecký, V.; Šamonil, P.; Matys Grygar, Tomáš; Vašát, R.; Ash, C.; Drahota, P.; Šebek, O.; Němeček, K.; Drábek, O.

    2015-01-01

    Roč. 132, SEP (2015), s. 12-20 ISSN 0341-8162 Institutional support: RVO:61388980 Keywords : Soil formation * Iron forms * Tree uprooting * Pit–mound microtopography * Cambisols * Old-growth temperate forest Subject RIV: DF - Soil Science Impact factor: 2.612, year: 2015

  5. Nitrogen deposition outweighs climatic variability in driving annual growth rate of canopy beech trees: evidence from long-term growth reconstruction across a geographic gradient.

    Science.gov (United States)

    Gentilesca, Tiziana; Rita, Angelo; Brunetti, Michele; Giammarchi, Francesco; Leonardi, Stefano; Magnani, Federico; van Noije, Twan; Tonon, Giustino; Borghetti, Marco

    2018-03-23

    In this study, we investigated the role of climatic variability and atmospheric nitrogen deposition in driving long-term tree growth in canopy beech trees along a geographic gradient in the montane belt of the Italian peninsula, from the Alps to the southern Apennines. We sampled dominant trees at different developmental stages (from young to mature tree cohorts, with tree ages spanning from 35 to 160 years) and used stem analysis to infer historic reconstruction of tree volume and dominant height. Annual growth volume (G V ) and height (G H ) variability were related to annual variability in model simulated atmospheric nitrogen deposition and site-specific climatic variables, (i.e. mean annual temperature, total annual precipitation, mean growing period temperature, total growing period precipitation, and standard precipitation evapotranspiration index) and atmospheric CO 2 concentration, including tree cambial age among growth predictors. Generalized additive models (GAM), linear mixed-effects models (LMM), and Bayesian regression models (BRM) were independently employed to assess explanatory variables. The main results from our study were as follows: i) tree age was the main explanatory variable for long-term growth variability; ii) GAM, LMM, and BRM results consistently indicated climatic variables and CO 2 effects on G V and G H were weak, therefore evidence of recent climatic variability influence on beech annual growth rates was limited in the montane belt of the Italian peninsula; iii) instead, significant positive nitrogen deposition (N dep ) effects were repeatedly observed in G V and G H ; the positive effects of N dep on canopy height growth rates, which tended to level off at N dep values greater than approximately 1.0 g m -2 y -1 were interpreted as positive impacts on forest stand above-ground net productivity at the selected study sites. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights

  6. Conspecific negative density dependence in American beech

    Directory of Open Access Journals (Sweden)

    Benjamin S. Ramage

    2017-06-01

    Full Text Available Background One of the most important drivers of forest biodiversity is conspecific negative density dependence (CNDD, a reduction in performance when conspecific densities are high. While the majority of CNDD research has focused on tropical forests, evidence is mounting that CNDD may also play an important role in temperate forests. To further explore the potential reach of this phenomenon, we investigated CNDD in American beech (Fagus grandifolia in a mature mid-Atlantic forest. Methods We used bivariate point pattern analyses to examine spatial relationships between large beech trees and conspecific saplings, and we also contrasted these patterns with comparable patterns for heterospecifics. In addition, to address the possibility of dispersal limitation and the associated effects on spatial patterns, we analyzed seedling density as a function of adult conspecific abundance. Results We found that beech saplings were more repelled from large conspecifics than large heterospecifics, despite the fact that beech seedling density was positively correlated with beech basal area. However, saplings of other canopy tree species were also repelled from adult beech trees, suggesting a general suppressive effect. Nonetheless, the discrepancy between beech seedling and sapling densities beneath adult conspecifics suggests that beech seedling survival rates were reduced in vicinity of conspecific adults. Conclusions Regardless of the extent to which beech inhibits heterospecific trees, a negative effect on conspecific recruits may be critical for biodiversity maintenance. Without this conspecific suppression, a dense layer of shade-tolerant beech saplings could form beneath adult beech trees. If this were to occur, beech would have a substantial head-start following canopy disturbance, and this late-successional species could potentially dominate a stand in perpetuity, through repeated disturbance cycles.

  7. Ozone fumigation (twice ambient) reduces leaf infestation following natural and artificial inoculation by the endophytic fungus Apiognomonia errabunda of adult European beech trees

    International Nuclear Information System (INIS)

    Olbrich, Maren; Knappe, Claudia; Wenig, Marion; Gerstner, Elke; Haeberle, Karl-Heinz; Kitao, Mitsutoshi; Matyssek, Rainer; Stich, Susanne; Leuchner, Michael; Werner, Herbert; Schlink, Katja; Mueller-Starck, Gerhard; Welzl, Gerhard; Scherb, Hagen; Ernst, Dieter; Heller, Werner; Bahnweg, Guenther

    2010-01-01

    In 2006, a controlled infection study was performed in the 'Kranzberger Forst' to address the following questions: (1) Will massive artificial inoculation with Apiognomonia errabunda override the previously observed inhibitory effect of chronic ozone? (2) Can biochemical or molecular markers be detected to account for the action of ozone? To this end six adult beech trees were chosen, three ozone fumigated (2x ozone) and three control trees (ambient = 1x ozone). Spore-sprayed branches of sun and shade crown positions of each of the trees, and uninoculated control branches, were enclosed in 100-L plastic bags for one night to facilitate infection initiation. Samples were taken within a five-week period after inoculation. A. errabunda infestation levels quantified by real-time PCR increased in leaves that were not fumigated with additional ozone. Cell wall components and ACC (ethylene precursor 1-amino cyclopropane-1-carboxylic acid) increased upon ozone fumigation and may in part lead to the repression of fungal infection. - Chronic sublethal ozone exposure reduces both natural and artificial infestation of beech leaves by the endophytic fungus Apiognomonia errabunda.

  8. Ozone fumigation (twice ambient) reduces leaf infestation following natural and artificial inoculation by the endophytic fungus Apiognomonia errabunda of adult European beech trees

    Energy Technology Data Exchange (ETDEWEB)

    Olbrich, Maren; Knappe, Claudia; Wenig, Marion; Gerstner, Elke [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Haeberle, Karl-Heinz; Kitao, Mitsutoshi; Matyssek, Rainer [Forest Botany, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Stich, Susanne [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Leuchner, Michael; Werner, Herbert [Bioclimatology, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Schlink, Katja; Mueller-Starck, Gerhard [Section of Forest Genetics, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Welzl, Gerhard [Institute of Developmental Genetics, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Scherb, Hagen [Institute of Biomathematics and Biometry, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Ernst, Dieter; Heller, Werner [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Bahnweg, Guenther, E-mail: bahnweg@helmholtz-muenchen.d [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany)

    2010-04-15

    In 2006, a controlled infection study was performed in the 'Kranzberger Forst' to address the following questions: (1) Will massive artificial inoculation with Apiognomonia errabunda override the previously observed inhibitory effect of chronic ozone? (2) Can biochemical or molecular markers be detected to account for the action of ozone? To this end six adult beech trees were chosen, three ozone fumigated (2x ozone) and three control trees (ambient = 1x ozone). Spore-sprayed branches of sun and shade crown positions of each of the trees, and uninoculated control branches, were enclosed in 100-L plastic bags for one night to facilitate infection initiation. Samples were taken within a five-week period after inoculation. A. errabunda infestation levels quantified by real-time PCR increased in leaves that were not fumigated with additional ozone. Cell wall components and ACC (ethylene precursor 1-amino cyclopropane-1-carboxylic acid) increased upon ozone fumigation and may in part lead to the repression of fungal infection. - Chronic sublethal ozone exposure reduces both natural and artificial infestation of beech leaves by the endophytic fungus Apiognomonia errabunda.

  9. Drought as a modifier of interaction between adult beech and spruce - impacts on tree water use, C budgets and biotic interactions above- and belowground

    Science.gov (United States)

    Grams, Thorsten

    2017-04-01

    Understanding biotic interactions among tree species with their microbial associates under drought will be crucial for silviculture in meeting ecological challenges of the future. This contribution gives an overview on a project integrating a throughfall-exclusion experiment (TEE) on adult trees with a natural precipitation gradient (PGR) in central European forests. Focus is on drought affecting species interaction above and belowground, including associated ectomycorrhizal (ECM) communities. Study objects are pure and mixed forests dominated by adult European beech and Norway spruce trees (c. 70-years old). At the throughfall-exclusion experiment (TEE), trees are readily accessible via scaffolding and canopy crane (Kranzberg Forest, southern Germany). Effects of experimentally induced, repeated summer drought are assessed with roughly 100 trees assigned to a total of 12 plots (Kranzberg forest ROOF experiment, kroof.wzw.tum.de). The summer drought treatment started in 2014 and was repeated in 2015 and 2106. The focus on species interaction is intensified by a parallel study along a natural precipitation gradient with plot triplets of monocultures and mixed cultures of European beech and Norway spruce at each of the five study sites. Complementary resource use, effects of competitive vs. facilitation and related changes in ECM communities are exemplified for the two tree species of contrasting foliage (i.e. deciduous vs. evergreen) and stomatal sensitivity to drought (i.e. an-isohydric vs. isohydric behavior). At the TEE site, precipitation throughfall was completely excluded from early spring to late fall (i.e. March to November), resulting in pre-dawn leaf water potentials of both beech and spruce as low as -2.5 MPa. Despite significant reductions in growth and rate of photosynthesis by up to 80% under drought, NSC budget of trees was hardly affected. Moreover, phloem functionality, tested as phloem transport velocity through 13C-labeling of recent

  10. Phosphorus resorption by young beech trees and soil phosphatase activity as dependent on phosphorus availability.

    Science.gov (United States)

    Hofmann, Kerstin; Heuck, Christine; Spohn, Marie

    2016-06-01

    Motivated by decreasing foliar phosphorus (P) concentrations in Fagus sylvatica L. forests, we studied P recycling depending on P fertilization in mesocosms with juvenile trees and soils of two contrasting F. sylvatica L. forests in a greenhouse. We hypothesized that forests with low soil P availability are better adapted to recycle P than forests with high soil P availability. The P resorption efficiency from senesced leaves was significantly higher at the P-poor site (70 %) than at the P-rich site (48 %). P fertilization decreased the resorption efficiency significantly at the P-poor site to 41 %, while it had no effect at the P-rich site. Both acid and alkaline phosphatase activity were higher in the rhizosphere of the P-poor than of the P-rich site by 53 and 27 %, respectively, while the activities did not differ in the bulk soil. Fertilization decreased acid phosphatase activity significantly at the P-poor site in the rhizosphere, but had no effect on the alkaline, i.e., microbial, phosphatase activity at any site. Acid phosphatase activity in the P-poor soil was highest in the rhizosphere, while in the P-rich soil, it was highest in the bulk soil. We conclude that F. sylvatica resorbed P more efficiently from senescent leaves at low soil P availability than at high P availability and that acid phosphatase activity in the rhizosphere but not in the bulk soil was increased at low P availability. Moreover, we conclude that in the P-rich soil, microbial phosphatases contributed more strongly to total phosphatase activity than plant phosphatases.

  11. Effect of tree size and competition on tension wood production over time in beech plantations and assessing relative gravitropic response with a biomechanical model.

    Science.gov (United States)

    Dassot, Mathieu; Fournier, Meriem; Ningre, François; Constant, Thiéry

    2012-09-01

    Gravitropic movements are unexpected mechanical processes that could disturb tree design allometries derived from the physics of nonliving bodies. We investigated whether the scaling law of gravitropic performance (power of -2 of stem diameter) derived from integrative biomechanical modeling is disturbed by ontogeny or environment, then discuss the silvicultural and dendroecological consequences. In a beech (Fagus sylvatica) plantation, four plots with different initial planting densities evolved without any intervention for 26 yr. Regular tree inventories and a silvicultural model were used to monitor competition over time in each plot. The radial production of tension wood was quantified using a cross-section of the stems at 1.30-m height, and an integrative biomechanical model computed the tree gravitropic performance over time. All trees developed tension wood over the whole period, with higher amounts at the youngest age, resulting in theoretical lean corrections of ca. 20-30° on the first 4 m of the stem over the whole period. The scaling law of gravitropic performance is slightly larger than the power of -2 of stem diameter. Gravitropic performance in forest ecosystems is mainly limited by size (diameter). Ontogenic acclimation of tension wood formation allows the youngest trees to be more reactive. No additional effect of spacing was found. However, silviculture influences size and, therefore, tree reactivity at a given age. Such results will be helpful for dendroecological approaches that use wood as a marker of environmental disturbances or a trait linked to plant strategies.

  12. Calcium biogeochemical cycle at the beech tree-soil solution interface from the Strengbach CZO (NE France): insights from stable Ca and radiogenic Sr isotopes

    Science.gov (United States)

    Schmitt, Anne-Désirée; Gangloff, Sophie; Labolle, François; Chabaux, François; Stille, Peter

    2017-09-01

    Calcium (Ca) is the fourth most abundant element in mineral nutrition and plays key physiological and structural roles in plant metabolism. At the soil-water-plant scale, stable Ca isotopes are a powerful tool for the identification of plant-mineral interactions and recycling via vegetation. Radiogenic Sr isotopes are often used as tracers of Ca sources and mixtures of different reservoirs. In this study, stable Ca and radiogenic Sr are combined and analysed in several organs from two beech trees that were collected in June and September in the Strengbach critical zone observatory (CZO) (NE France) and in corresponding soil solutions. At the beech-tree scale, this study confirms the field Ca adsorption (i.e., physico-chemical mechanism and not vital effects) on carboxyl acid groups of pectin in the apoplasm of small roots. The analysis of the xylem sap and corresponding organs shows that although the Strengbach CZO is nutrient-poor, Ca seems to be non-limiting for tree-growth. Different viscosities of xylem sap between the stemwood and branches or leaves can explain δ44/40Ca values in different tree-organs. The bark and phloem 40Ca-enrichments could be due to Ca-oxalate precipitation in the bark tissues and in the phloem. The results from this study regarding the combination of these two isotopic systems show that the isotopic signatures of the roots are dominated by Ca fractionation mechanisms and Sr, and thus Ca, source variations. In contrast, translocation mechanisms are only governed by Ca fractionation processes. This study showed that at the root-soil solution interface, litter degradation was not the main source of Ca and Sr and that the soil solutions are not the complement of uptake by roots for samples from the 2011/2013 period. The opposite is observed for older samples. These observations indicate the decreasing contribution of low radiogenic Sr fluxes, such as recycling, alimenting the soil solutions. Such reduced importance of nutrient uptake and

  13. VEGETATION DYNAMICS IN EUROPEAN BEECH FORESTS

    Directory of Open Access Journals (Sweden)

    A. FISCHER

    1997-01-01

    Full Text Available Dynamic processes can be classified in terms of their time scale, their spatial scale, the elements observed, and the degree of human impact. Using these categories the regeneration of the tree layer, the regeneration of the herb layer as well as successional changes of supraregional importance (immissions, global change are discussed. A virgin (mixed European beech forest consists of a mosaic of sub-stands that can be typified by their structure and developmental stage (phase of the tree layer; in some phases the tree individuals of each sub-stand are rather even-aged. Natural cyclic regeneration of virgin (mixed European beech forests mainly includes the tree species of the terminal phases, expecially the beech itself. Changes of tree species composition within the cycle are the exception; in European beech forests light-demanding pioneers seem to be restricted to rather small patches under natural conditions. In contrast, the sequence (1 felled-area flora, (2 pioneer shrub/pioneer forest and (3 terminal forest is a characteristic feature of managed deciduous forests as a consequence of soil disturbances. During the cyclic regeneration of the tree layer of European beech forests the floristic content of the ground layer vegetation does not change fundamentally. Regeneration of many of the ground layer species of beech forests via generative diaspores is more or less restricted to micro-disturbances. In contrast disturbance of the topsoil and creation of open habitats for the establishment of saplings in the absence of competition is taking place all over a clear-cutting area. European beech forests are subject to changes of floristic structure caused by immissions. Especially nitrogen, emitted over decades in large quantities, causes a successive change in floristics: species requiring high amounts of nitrogen are increasing in beech forests all over Europe. Most of them are rapidly and tall growing species, outcompeting the slower and smaller

  14. Thermopower of beech wood biocarbon

    Science.gov (United States)

    Smirnov, I. A.; Smirnov, B. I.; Orlova, T. S.; Sulkovski, Cz.; Misiorek, H.; Jezowski, A.; Muha, J.

    2011-11-01

    This paper reports on measurements of the thermopower S of high-porosity samples of beech wood biocarbon with micron-sized sap pores aligned with the tree growth direction. The measurements have been performed in the temperature range 5-300 K. The samples have been fabricated by pyrolysis of beech wood in an argon flow at different carbonization temperatures ( T carb). The thermopower S has been measured both along and across the sap pores, thus offering a possibility of assessing its anisotropy. The curves S( T carb) have revealed a noticeable increase of S for T carb biocarbons, which suggests that for T carb ˜ 1000°C they undergo a phase transition of the insulator-(at T carb 1000°C) type. The existence of this transition is attested also by the character of the temperature dependences S( T) of beech wood biocarbon samples prepared at T carb above and below 1000°C.

  15. Influence of Root Diameter and Soil Depth on the Xylem Anatomy of Fine- to Medium-Sized Roots of Mature Beech Trees in the Top- and Subsoil.

    Science.gov (United States)

    Kirfel, Kristina; Leuschner, Christoph; Hertel, Dietrich; Schuldt, Bernhard

    2017-01-01

    Despite their importance for water uptake and transport, the xylem anatomical and hydraulic properties of tree roots have only rarely been studied in the field. We measured mean vessel diameter ( D ), vessel density (VD), relative vessel lumen area (lumen area per xylem area) and derived potential hydraulic conductivity ( K p ) in the xylem of 197 fine- to medium-diameter roots (1-10 mm) in the topsoil and subsoil (0-200 cm) of a mature European beech forest on sandy soil for examining the influence of root diameter and soil depth on xylem anatomical and derived hydraulic traits. All anatomical and functional traits showed strong dependence on root diameter and thus root age but no significant relation to soil depth. Averaged over topsoil and deep soil and variable flow path lengths in the roots, D increased linearly with root diameter from ∼50 μm in the smallest diameter class (1-2 mm) to ∼70 μm in 6-7 mm roots (corresponding to a mean root age of ∼12 years), but remained invariant in roots >7 mm. D never exceeded ∼82 μm in the 1-10 mm roots, probably in order to control the risk of frost- or drought-induced cavitation. This pattern was overlain by a high variability in xylem anatomy among similar-sized roots with K p showing a higher variance component within than between root diameter classes. With 8% of the roots exceeding average K p in their diameter class by 50-700%, we obtained evidence of the existence of 'high-conductivity roots' indicating functional differentiation among similar-sized roots. We conclude that the hydraulic properties of small to medium diameter roots of beech are mainly determined by root age, rendering root diameter a suitable predictor of hydraulic functioning, while soil depth - without referring to path length - had a negligible effect.

  16. Influence of Root Diameter and Soil Depth on the Xylem Anatomy of Fine- to Medium-Sized Roots of Mature Beech Trees in the Top- and Subsoil

    Directory of Open Access Journals (Sweden)

    Kristina Kirfel

    2017-07-01

    Full Text Available Despite their importance for water uptake and transport, the xylem anatomical and hydraulic properties of tree roots have only rarely been studied in the field. We measured mean vessel diameter (D, vessel density (VD, relative vessel lumen area (lumen area per xylem area and derived potential hydraulic conductivity (Kp in the xylem of 197 fine- to medium-diameter roots (1–10 mm in the topsoil and subsoil (0–200 cm of a mature European beech forest on sandy soil for examining the influence of root diameter and soil depth on xylem anatomical and derived hydraulic traits. All anatomical and functional traits showed strong dependence on root diameter and thus root age but no significant relation to soil depth. Averaged over topsoil and deep soil and variable flow path lengths in the roots, D increased linearly with root diameter from ∼50 μm in the smallest diameter class (1–2 mm to ∼70 μm in 6–7 mm roots (corresponding to a mean root age of ∼12 years, but remained invariant in roots >7 mm. D never exceeded ∼82 μm in the 1–10 mm roots, probably in order to control the risk of frost- or drought-induced cavitation. This pattern was overlain by a high variability in xylem anatomy among similar-sized roots with Kp showing a higher variance component within than between root diameter classes. With 8% of the roots exceeding average Kp in their diameter class by 50–700%, we obtained evidence of the existence of ‘high-conductivity roots’ indicating functional differentiation among similar-sized roots. We conclude that the hydraulic properties of small to medium diameter roots of beech are mainly determined by root age, rendering root diameter a suitable predictor of hydraulic functioning, while soil depth – without referring to path length – had a negligible effect.

  17. Assessing the risk caused by ground level ozone to European forest trees: A case study in pine, beech and oak across different climate regions

    International Nuclear Information System (INIS)

    Emberson, Lisa D.; Bueker, Patrick; Ashmore, Mike R.

    2007-01-01

    Two different indices have been proposed for estimation of the risk caused to forest trees across Europe by ground-level ozone, (i) the concentration based AOT40 index (Accumulated Over a Threshold of 40 ppb) and (ii) the recently developed flux based AFstY index (Accumulated stomatal Flux above a flux threshold Y). This paper compares the AOT40 and AFstY indices for three forest trees species at different locations in Europe. The AFstY index is estimated using the DO 3 SE (Deposition of Ozone and Stomatal Exchange) model parameterized for Scots pine (Pinus sylvestris), beech (Fagus sylvatica) and holm oak (Quercus ilex). The results show a large difference in the perceived O 3 risk when using AOT40 and AFstY indices both between species and regions. The AOT40 index shows a strong north-south gradient across Europe, whereas there is little difference between regions in the modelled values of AFstY. There are significant differences in modelled AFstY between species, which are predominantly determined by differences in the timing and length of the growing season, the periods during which soil moisture deficit limits stomatal conductance, and adaptation to soil moisture stress. This emphasizes the importance of defining species-specific flux response variables to obtain a more accurate quantification of O 3 risk. - A new flux-based model provides a revised assessment of risks of ozone impacts to European forests

  18. Belowground carbon allocation by trees drives seasonal patterns of extracellular enzyme activities by altering microbial community composition in a beech forest soil.

    Science.gov (United States)

    Kaiser, Christina; Koranda, Marianne; Kitzler, Barbara; Fuchslueger, Lucia; Schnecker, Jörg; Schweiger, Peter; Rasche, Frank; Zechmeister-Boltenstern, Sophie; Sessitsch, Angela; Richter, Andreas

    2010-08-01

    *Plant seasonal cycles alter carbon (C) and nitrogen (N) availability for soil microbes, which may affect microbial community composition and thus feed back on microbial decomposition of soil organic material and plant N availability. The temporal dynamics of these plant-soil interactions are, however, unclear. *Here, we experimentally manipulated the C and N availability in a beech forest through N fertilization or tree girdling and conducted a detailed analysis of the seasonal pattern of microbial community composition and decomposition processes over 2 yr. *We found a strong relationship between microbial community composition and enzyme activities over the seasonal course. Phenoloxidase and peroxidase activities were highest during late summer, whereas cellulase and protease peaked in late autumn. Girdling, and thus loss of mycorrhiza, resulted in an increase in soil organic matter-degrading enzymes and a decrease in cellulase and protease activity. *Temporal changes in enzyme activities suggest a switch of the main substrate for decomposition between summer (soil organic matter) and autumn (plant litter). Our results indicate that ectomycorrhizal fungi are possibly involved in autumn cellulase and protease activity. Our study shows that, through belowground C allocation, trees significantly alter soil microbial communities, which may affect seasonal patterns of decomposition processes.

  19. Thinning in artificially regenerated young beech stands

    Directory of Open Access Journals (Sweden)

    Novák Jiří

    2015-12-01

    Full Text Available Although beech stands are usually regenerated naturally, an area of up to 5,000 ha year−1 is artificially regenerated by beech in the Czech Republic annually. Unfortunately, these stands often showed insufficient stand density and, consequently, lower quality of stems. Therefore, thinning methods developed for naturally regenerated beech stands are applicable with difficulties. The paper evaluates the data from two thinning experiments established in young artificially regenerated beech stands located in different growing conditions. In both experiments, thinning resulted in the lower amount of salvage cut in following years. Positive effect of thinning on periodic stand basal area increment and on periodic diameter increment of dominant trees was found in the beech stand located at middle elevations. On the other hand, thinning effects in mountain conditions were negligible. Thinning focusing on future stand quality cannot be commonly applied in artificially regenerated beech stands because of their worse initial quality and lower density. However, these stands show good growth and response to thinning, hence their management can be focused on maximising beech wood production.

  20. Development of molecular tools for use in beech bark disease management

    Science.gov (United States)

    Jennifer L. Koch; David W. Carey; Mary E. Mason; C. Dana Nelson; Abdelali Barakat; John E. Carlson; David. Neale

    2011-01-01

    Beech bark disease (BBD) has been killing American beech trees in eastern North America since the late 1890s. The disease is initiated by feeding of the beech scale insect, Cryptococcus fagisuga, which leads to the development of small fissures in the bark.

  1. Contrasting effects of environmental change on the radial growth of co-occurring beech and fir trees across Europe

    Czech Academy of Sciences Publication Activity Database

    Bošela, M.; Lukac, M.; Castagneri, D.; Sedmák, R.; Biber, P.; Carrer, M.; Konopka, B.; Nola, P.; Nagel, T.; Popa, I.; Roibu, C. C.; Svoboda, M.; Trotsiuk, V.; Büntgen, Ulf

    2018-01-01

    Roč. 615, feb (2018), s. 1460-1469 ISSN 0048-9697 Institutional support: RVO:86652079 Keywords : fagus-sylvatica l. * abies-alba * silver fir * climate-change * site productivity * summer drought * norway spruce * bark beetle * range core * forests * Dendroecology * Climate change * Growth sensitivity * Mixed forests * Plant-climate interactions * Tree rings Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental science s (social aspects to be 5.7) Impact factor: 4.900, year: 2016

  2. Comparisons of protein profiles of beech bark disease resistant and susceptible American beech (Fagus grandifolia

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    Mason Mary E

    2013-01-01

    Full Text Available Abstract Background Beech bark disease is an insect-fungus complex that damages and often kills American beech trees and has major ecological and economic impacts on forests of the northeastern United States and southeastern Canadian forests. The disease begins when exotic beech scale insects feed on the bark of trees, and is followed by infection of damaged bark tissues by one of the Neonectria species of fungi. Proteomic analysis was conducted of beech bark proteins from diseased trees and healthy trees in areas heavily infested with beech bark disease. All of the diseased trees had signs of Neonectria infection such as cankers or fruiting bodies. In previous tests reported elsewhere, all of the diseased trees were demonstrated to be susceptible to the scale insect and all of the healthy trees were demonstrated to be resistant to the scale insect. Sixteen trees were sampled from eight geographically isolated stands, the sample consisting of 10 healthy (scale-resistant and 6 diseased/infested (scale-susceptible trees. Results Proteins were extracted from each tree and analysed in triplicate by isoelectric focusing followed by denaturing gel electrophoresis. Gels were stained and protein spots identified and intensity quantified, then a statistical model was fit to identify significant differences between trees. A subset of BBD differential proteins were analysed by mass spectrometry and matched to known protein sequences for identification. Identified proteins had homology to stress, insect, and pathogen related proteins in other plant systems. Protein spots significantly different in diseased and healthy trees having no stand or disease-by-stand interaction effects were identified. Conclusions Further study of these proteins should help to understand processes critical to resistance to beech bark disease and to develop biomarkers for use in tree breeding programs and for the selection of resistant trees prior to or in early stages of BBD

  3. Fifty-year impacts of the beech bark disease in the Bartlett Experimental Forest, New Hampshire

    Science.gov (United States)

    William B. Leak

    2006-01-01

    Records from the early 1950s on the Bartlett Experimental Forest in New Hampshire showed that the percentage of American beech trees infected with heavy beech scale and Nectria was up to the 80 to 90% range. An inventory of beech bark disease conditions in three stands in 2004 showed that an older, uneven-aged stand managed by individual tree selection for 50 years had...

  4. Hypoxylon species on beech and other broadleaves

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    Milijašević Tanja

    2004-01-01

    Full Text Available Fungi in the genus Hypoxylon cause wood decay and most of them are saprophytes on dead wood or parasites of weakness. The following species in this genus were identified in this study performed at several localities in Serbia and Montenegro: H. deustum, H. fragiforme, H. nummularium, H. multiforme, H. rubiginosum and H. fuscum. Among them the most significant species is H. deustum, the fungus causing root and butt rot of standing beech trees. It was recorded from all coppice and high forests of beech. This paper presents the morphological characteristics of the recorded fungi their range, plant hosts and significance.

  5. Beech forests of Azerbaijan: The modern condition, age structure and regeneration

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    Z.M. Hasanov

    2017-12-01

    Full Text Available Azerbaijan is a country with low forest cover, only 11.8% of the territory is covered with forests. All forests perform important water-soil-protection functions. In forests, naturally grow 107 species of trees and 328 shrubs species. Despite the fact that there are many species in dendroflora, only 10 tree species have economic value for the forest sector of the country. Beech (31.68%, oak (27.40% and hornbeam (26.01% are growing in 85.09% of forested areas. Beech forests are spread on 327 thousand hectares from 989,5 of total forest lands of he Republic. Beech forests are a source of high-quality wood and beech nuts. All beech forests grow in mountains at heights of 600–800 and 1600–1800 m above the sea level and performing important ecological functions. Until recently there were no problems with natural renewal of the beech forests, but now the regeneration of beech forests is alarming. In recent years, the productivity and density of beech forests decreased substantially, the natural regeneration proceeds unsatisfactorily and, consequently, reduction of beech forests takes place. We have researched 33,8 thousand hectares of beech forests of the Lesser Caucasus, their natural regeneration and made analysis of age structure of forests. Keywords: Fagus orientalis, Beech forests, Silviculture, Natural regeneration, Age class

  6. Space sequestration below ground in old-growth spruce-beech forests – signs for facilitation?

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    Andreas eBolte

    2013-08-01

    Full Text Available Scientists are currently debating the effects of mixing tree species for the complementary resource acquisition in forest ecosystems. In four unmanaged old-growth spruce-beech forests in strict nature reserves in southern Sweden and northern Germany we assessed forest structure and fine rooting profiles and traits (≤ 2 mm by fine root sampling and the analysis of fine root morphology and biomass. These studies were conducted in selected tree groups with four different interspecific competition perspectives: (1 spruce as a central tree, (2 spruce as competitor, (3 beech as a central tree, and (4 beech as competitor. Mean values of life fine root attributes like biomass (FRB, length (FRL, and root area index (RAI were significantly lower for spruce than for beech in mixed stands. Vertical profiles of fine root attributes adjusted to one unit of basal area (BA exhibited partial root system stratification when central beech is growing with spruce competitors. In this constellation, beech was able to raise its specific root length (SRL and therefore soil exploration efficiency in the subsoil, while increasing root biomass partitioning into deeper soil layers. According to relative values of fine root attributes (rFRA, asymmetric below-ground competition was observed favoring beech over spruce, in particular when central beech trees are admixed with spruce competitors. We conclude that beech fine rooting is facilitated in the presence of spruce by lowering competitive pressure compared to intraspecific competition whereas the competitive pressure for spruce is increased by beech admixture. Our findings underline the need of spatially differentiated approaches to assess interspecific competition below ground. Single-tree approaches and simulations of below-ground competition are required to focus rather on microsites populated by tree specimens as the basic spatial study area.

  7. A comparison of two stem injection treatments applied to American beech in central West Virginia

    Science.gov (United States)

    Jeffrey D. Kochenderfer; Gary W. Miller; James N. Kochenderfer

    2012-01-01

    Efficacies for two herbicide stem injection treatments on American beech (Fagus grandifolia Ehrh.) and impacts to nontarget residual trees were evaluated in central West Virginia. The treatments consisted of hack-and-squirt injection of all beech stems ≥1.0 in. to 9.9 in. diameter at breast height (d.b.h.) with either imazapyr as Arsenal...

  8. Effects of simultaneous ozone exposure and nitrogen loads on carbohydrate concentrations, biomass, growth, and nutrient concentrations of young beech trees (Fagus sylvatica)

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, V.F.D. [Institute for Applied Plant Biology, Sandgrubenstr. 25/27, 4124 Schoenenbuch (Switzerland)]. E-mail: vera.thomas@iap.ch; Braun, S. [Institute for Applied Plant Biology, Sandgrubenstr. 25/27, 4124 Schoenenbuch (Switzerland); Flueckiger, W. [Institute for Applied Plant Biology, Sandgrubenstr. 25/27, 4124 Schoenenbuch (Switzerland)

    2006-09-15

    Beech seedlings were grown under different nitrogen fertilisation regimes (0, 20, 40, and 80 kg N ha{sup -1} yr{sup -1}) for three years and were fumigated with either charcoal-filtered (F) or ambient air (O{sub 3}). Nitrogen fertilisation increased leaf necroses, aphid infestations, and nutrient ratios in the leaves (N:P and N:K), as a result of decreased phosphorus and potassium concentrations. For plant growth, biomass accumulation, and starch concentrations, a positive nitrogen effect was found, but only for fertilisations of up to 40 kg N ha{sup -1} yr{sup -1}. The highest nitrogen load, however, reduced leaf area, leaf water content, growth, biomass accumulation, and starch concentrations, whereas soluble carbohydrate concentrations were enhanced. The ozone fumigation resulted in reduced leaf area, leaf water content, shoot growth, root biomass accumulation, and decreased starch, phosphorus, and potassium concentrations, increasing the N:P and N:K ratios. A combined effect of the two pollutants was detected for the leaf area and the shoot elongation, where ozone fumigation amplified the nitrogen effects. - The effects of nitrogen and ozone on growth, carbohydrate concentrations, and nutrients are mainly additive.

  9. Assessing native small mammals' responses to an incipient invasion of beech bark disease through changes in seed production of American beech

    Science.gov (United States)

    Justin N. Rosemier; Andrew J. Storer

    2011-01-01

    Exotic tree diseases have direct impacts on their host and may have indirect effects on native fauna that rely on host tree species. For example, American beech (Fagus grandifolia [Ehrh.]) is a dominant overstory component throughout its range and, like all tree species, is vulnerable to a broad array of insects and pathogens. These pests include...

  10. Conservation genetics of the European beech in France

    Science.gov (United States)

    A. Ducousso; B. Musch; S. Irola; A. Quenu; A. Hampe; R.J. Petit

    2017-01-01

    European beech (Fagus sylvatica) is one of the most abundant tree species in Europe. Its genetic structure and diversity have been investigated using both molecular markers and adaptive traits as assessed in field and laboratory experimental tests looking at adaptative traits. A great deal of information also exists on the Quaternary history of the...

  11. Water shortage affects the water and nitrogen balance in Central European beech forests.

    Science.gov (United States)

    Gessler, A; Keitel, C; Nahm, M; Rennenberg, H

    2004-05-01

    Whilst forest policy promotes cultivation and regeneration of beech dominated forest ecosystems, beech itself is a highly drought sensitive tree species likely to suffer from the climatic conditions prognosticated for the current century. Taking advantage of model ecosystems with cool-moist and warm-dry local climate, the latter assumed to be representative for future climatic conditions, the effects of climate and silvicultural treatment (different thinning regimes) on water status, nitrogen balance and growth parameters of adult beech trees and beech regeneration in the understorey were assessed. In addition, validation experiments with beech seedlings were carried out under controlled conditions, mainly in order to assess the effect of drought on the competitive abilities of beech. As measures of water availability xylem flow, shoot water potential, stomatal conductance as well as delta (13)C and delta (18)O in different tissues (leaves, phloem, wood) were analysed. For the assessment of nitrogen balance we determined the uptake of inorganic nitrogen by the roots as well as total N content and soluble N compounds in different tissues of adult and young trees. Retrospective and current analysis of delta (13)C, growth and meteorological parameters revealed that beech growing under warm-dry climatic conditions were impaired in growth and water balance during periods with low rain-fall. Thinning affected water, N balance and growth mostly of young beech, but in a different way under different local climatic conditions. Under cool, moist conditions, representative for the current climatic and edaphic conditions in beech forests of Central Europe, thinning improves nutrient and water status consistent to published literature and long-term experience of forest practitioners. However, beech regeneration was impaired as a result of thinning at higher temperatures and under reduced water availability, as expected in future climate.

  12. Cascading effects of a highly specialized beech-aphid–fungus interaction on forest regeneration

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    Susan C. Cook-Patton

    2014-06-01

    Full Text Available Specialist herbivores are thought to often enhance or maintain plant diversity within ecosystems, because they prevent their host species from becoming competitively dominant. In contrast, specialist herbivores are not generally expected to have negative impacts on non-hosts. However, we describe a cascade of indirect interactions whereby a specialist sooty mold (Scorias spongiosa colonizes the honeydew from a specialist beech aphid (Grylloprociphilus imbricator, ultimately decreasing the survival of seedlings beneath American beech trees (Fagus grandifolia. A common garden experiment indicated that this mortality resulted from moldy honeydew impairing leaf function rather than from chemical or microbial changes to the soil. In addition, aphids consistently and repeatedly colonized the same large beech trees, suggesting that seedling-depauperate islands may form beneath these trees. Thus this highly specialized three-way beech-aphid–fungus interaction has the potential to negatively impact local forest regeneration via a cascade of indirect effects.

  13. Effect of stand edge on the natural regeneration of spruce, beech and Douglas-fir

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    Lumír Dobrovolný

    2012-01-01

    Full Text Available Our work aimed at studying the strategy of woody plants regeneration during the regeneration of a spruce stand with the admixture of beech and Douglas-fir by border cutting (NW-SE aspect on acidic sites of higher elevations in the Bohemian-Moravian Upland. Spruce is better adapted to bear shade than Douglas-fir. Nevertheless, in optimal light conditions up to a distance of ca. 35 m (about 16% DIFFSF from the stand edge, the Douglas-fir can put the spruce into danger as to height growth. By contrast to beech, the density of spruce is significantly higher within the distance of 45 m (about 15% DIFFSF from the stand edge but further on the situation would change to the benefit of beech. The density of Douglas-fir significantly dominates over beech within a distance of 35 m from the stand edge; from 55 m (less than 15% DIFFSF, the situation changes in favour of beech. Beech can survive in full shade deep in the stand core waiting for its opportunity to come. As compared to spruce and Douglas-fir, the height growth of beech was at all times significantly greater at a distance of 25 m from the stand edge. Converted to practical conditions, spruce and Douglas-fir with individually admixed beech seedlings showed good prosperity approximately up to a distance of one stand height from the edge. A mixture of spruce and beech did well at a greater distance but good prosperity at a distance of 2–3 stand heights was shown only by beech. Thus, border regeneration eliminates disadvantages of the climatic extremes of clear-cutting and specifics of shelterwood felling during which one – usually shade-tolerant tree species dominates in the natural regeneration (e.g. beech.

  14. Variation in Ecophysiological Traits and Drought Tolerance of Beech (Fagus sylvatica L.) Seedlings from Different Populations

    Science.gov (United States)

    Cocozza, Claudia; de Miguel, Marina; Pšidová, Eva; Ditmarová, L'ubica; Marino, Stefano; Maiuro, Lucia; Alvino, Arturo; Czajkowski, Tomasz; Bolte, Andreas; Tognetti, Roberto

    2016-01-01

    Frequency and intensity of heat waves and drought events are expected to increase in Europe due to climate change. European beech (Fagus sylvatica L.) is one of the most important native tree species in Europe. Beech populations originating throughout its native range were selected for common-garden experiments with the aim to determine whether there are functional variations in drought stress responses among different populations. One-year old seedlings from four to seven beech populations were grown and drought-treated in a greenhouse, replicating the experiment at two contrasting sites, in Italy (Mediterranean mountains) and Germany (Central Europe). Experimental findings indicated that: (1) drought (water stress) mainly affected gas exchange describing a critical threshold of drought response between 30 and 26% SWA for photosynthetic rate and Ci/Ca, respectively; (2) the Ci to Ca ratio increased substantially with severe water stress suggesting a stable instantaneous water use efficiency and an efficient regulation capacity of water balance achieved by a tight stomatal control; (3) there was a different response to water stress among the considered beech populations, differently combining traits, although there was not a well-defined variability in drought tolerance. A combined analysis of functional and structural traits for detecting stress signals in beech seedlings is suggested to assess plant performance under limiting moisture conditions and, consequently, to estimate evolutionary potential of beech under a changing environmental scenario. PMID:27446118

  15. Differential Responses of Herbivores and Herbivory to Management in Temperate European Beech

    Science.gov (United States)

    Gossner, Martin M.; Pašalić, Esther; Lange, Markus; Lange, Patricia; Boch, Steffen; Hessenmöller, Dominik; Müller, Jörg; Socher, Stephanie A.; Fischer, Markus; Schulze, Ernst-Detlef; Weisser, Wolfgang W.

    2014-01-01

    Forest management not only affects biodiversity but also might alter ecosystem processes mediated by the organisms, i.e. herbivory the removal of plant biomass by plant-eating insects and other arthropod groups. Aiming at revealing general relationships between forest management and herbivory we investigated aboveground arthropod herbivory in 105 plots dominated by European beech in three different regions in Germany in the sun-exposed canopy of mature beech trees and on beech saplings in the understorey. We separately assessed damage by different guilds of herbivores, i.e. chewing, sucking and scraping herbivores, gall-forming insects and mites, and leaf-mining insects. We asked whether herbivory differs among different forest management regimes (unmanaged, uneven-aged managed, even-aged managed) and among age-classes within even-aged forests. We further tested for consistency of relationships between regions, strata and herbivore guilds. On average, almost 80% of beech leaves showed herbivory damage, and about 6% of leaf area was consumed. Chewing damage was most common, whereas leaf sucking and scraping damage were very rare. Damage was generally greater in the canopy than in the understorey, in particular for chewing and scraping damage, and the occurrence of mines. There was little difference in herbivory among differently managed forests and the effects of management on damage differed among regions, strata and damage types. Covariates such as wood volume, tree density and plant diversity weakly influenced herbivory, and effects differed between herbivory types. We conclude that despite of the relatively low number of species attacking beech; arthropod herbivory on beech is generally high. We further conclude that responses of herbivory to forest management are multifaceted and environmental factors such as forest structure variables affecting in particular microclimatic conditions are more likely to explain the variability in herbivory among beech forest

  16. Trypodendron domesticum and Trypodendron signatum: two scolytid species involved in beech decline in Belgium

    Science.gov (United States)

    B. Gaubicher; M. De Proft; J.-C. Gregoire

    2003-01-01

    Xylophagous scolytids (Ambrosia beetles) have long been known to prefer fallen or seriously weakened trees and stumps. They are attracted to this host material by ethanol produced by the fermenting phloem and sapwood. However, these insects have begun aggressively attacking living beeches in Southern Belgium, raising the issue of a possible shift towards primarity....

  17. Qualitative survey of five beech damaging Coleoptera (Scolytidae and Lymexylonidae) in Wallonia (Southern Belgium)

    Science.gov (United States)

    Jean-Marc Henin; Olivier Huart; Phillipe Lejeune; Jacques Rondeux

    2003-01-01

    In 2000 and 2001, Trypodendron domesticum L. and T. signatum (F.) (Col.: Scolytidae) were one of the main causes of the depreciation of more than 1,600,000 m³ of standing beech trees, Fagus sylvatica L., in Wallonia (Southern Belgium). In 2001, a survey aiming at assessing the range of those indigenous...

  18. Diversity of dead wood inhabiting fungal and bryophytes in semi-natural beech forests in Europe

    NARCIS (Netherlands)

    Ódor, P.; Heilmann-Clausen, J.; Christensen, M.; Aude, E.; Dort, van K.W.; Piltaver, A.; Siller, I.; Veerkamp, M.T.; Walleyn, R.; Standovár, T.; Hees, van A.F.M.; Kosec, J.; Matocec, N.; Kraigher, H.; Grebenc, T.

    2006-01-01

    Saproxylic organisms are among the most threatened species in Europe and constitute a major conservation problem because they depend on the most important forestry product - dead wood. Diversity of fungal and bryophyte communities occurring on dead beech trees was analyzed in five European countries

  19. Beech cupules as keystone structures for soil fauna.

    Science.gov (United States)

    Melguizo-Ruiz, Nereida; Jiménez-Navarro, Gerardo; Moya-Laraño, Jordi

    2016-01-01

    Facilitative or positive interactions are ubiquitous in nature and play a fundamental role in the configuration of ecological communities. In particular, habitat modification and niche construction, in which one organism locally modifies abiotic conditions and favours other organisms by buffering the effects of adverse environmental factors, are among the most relevant facilitative interactions. In line with this, 'keystone structures', which provide resources, refuge, or advantageous services decisive for other species, may allow the coexistence of various species and thus considerably contribute to diversity maintenance. Beech cupules are woody husks harbouring beech fruits that remain in the forest soil for relatively long periods of time. In this study, we explored the potential role of these cupules in the distribution and maintenance of the soil fauna inhabiting the leaf litter layer. We experimentally manipulated cupule availability and soil moisture in the field to determine if such structures are limiting and can provide moist shelter to soil animals during drought periods, contributing to minimize desiccation risks. We measured invertebrate abundances inside relative to outside the cupules, total abundances in the leaf litter and animal body sizes, in both dry and wet experimental plots. We found that these structures are preferentially used by the most abundant groups of smaller soil animals-springtails, mites and enchytraeids-during droughts. Moreover, beech cupules can be limiting, as an increase in use was found with higher cupule densities, and are important resources for many small soil invertebrates, driving the spatial structure of the soil community and promoting higher densities in the leaf litter, probably through an increase in habitat heterogeneity. We propose that fruit woody structures should be considered 'keystone structures' that contribute to soil community maintenance. Therefore, beech trees may indirectly facilitate soil fauna

  20. Beech cupules as keystone structures for soil fauna

    Directory of Open Access Journals (Sweden)

    Nereida Melguizo-Ruiz

    2016-10-01

    Full Text Available Facilitative or positive interactions are ubiquitous in nature and play a fundamental role in the configuration of ecological communities. In particular, habitat modification and niche construction, in which one organism locally modifies abiotic conditions and favours other organisms by buffering the effects of adverse environmental factors, are among the most relevant facilitative interactions. In line with this, ‘keystone structures’, which provide resources, refuge, or advantageous services decisive for other species, may allow the coexistence of various species and thus considerably contribute to diversity maintenance. Beech cupules are woody husks harbouring beech fruits that remain in the forest soil for relatively long periods of time. In this study, we explored the potential role of these cupules in the distribution and maintenance of the soil fauna inhabiting the leaf litter layer. We experimentally manipulated cupule availability and soil moisture in the field to determine if such structures are limiting and can provide moist shelter to soil animals during drought periods, contributing to minimize desiccation risks. We measured invertebrate abundances inside relative to outside the cupules, total abundances in the leaf litter and animal body sizes, in both dry and wet experimental plots. We found that these structures are preferentially used by the most abundant groups of smaller soil animals—springtails, mites and enchytraeids—during droughts. Moreover, beech cupules can be limiting, as an increase in use was found with higher cupule densities, and are important resources for many small soil invertebrates, driving the spatial structure of the soil community and promoting higher densities in the leaf litter, probably through an increase in habitat heterogeneity. We propose that fruit woody structures should be considered ‘keystone structures’ that contribute to soil community maintenance. Therefore, beech trees may

  1. Anthropogenic nitrogen deposition alters growth responses of European beech (Fagus sylvativa L.) to climate change.

    Science.gov (United States)

    Hess, Carsten; Niemeyer, Thomas; Fichtner, Andreas; Jansen, Kirstin; Kunz, Matthias; Maneke, Moritz; von Wehrden, Henrik; Quante, Markus; Walmsley, David; von Oheimb, Goddert; Härdtle, Werner

    2018-02-01

    Global change affects the functioning of forest ecosystems and the services they provide, but little is known about the interactive effects of co-occurring global change drivers on important functions such as tree growth and vitality. In the present study we quantified the interactive (i.e. synergistic or antagonistic) effects of atmospheric nitrogen (N) deposition and climatic variables (temperature, precipitation) on tree growth (in terms of tree-ring width, TRW), taking forest ecosystems with European beech (Fagus sylvatica L.) as an example. We hypothesised that (i) N deposition and climatic variables can evoke non-additive responses of the radial increment of beech trees, and (ii) N loads have the potential to strengthen the trees' sensitivity to climate change. In young stands, we found a synergistic positive effect of N deposition and annual mean temperature on TRW, possibly linked to the alleviation of an N shortage in young stands. In mature stands, however, high N deposition significantly increased the trees' sensitivity to increasing annual mean temperatures (antagonistic effect on TRW), possibly due to increased fine root dieback, decreasing mycorrhizal colonization or shifts in biomass allocation patterns (aboveground vs. belowground). Accordingly, N deposition and climatic variables caused both synergistic and antagonistic effects on the radial increment of beech trees, depending on tree age and stand characteristics. Hence, the nature of interactions could mediate the long-term effects of global change drivers (including N deposition) on forest carbon sequestration. In conclusion, our findings illustrate that interaction processes between climatic variables and N deposition are complex and have the potential to impair growth and performance of European beech. This in turn emphasises the importance of multiple-factor studies to foster an integrated understanding and models aiming at improved projections of tree growth responses to co-occurring drivers

  2. Pregermination Treatment and Germination Characteristics of Oriental Beech (Fagus orientalis Lipsky in the Caspian Region

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    REZAII, Afsaneh

    2010-01-01

    Full Text Available Oriental beech is one of the most important tree species in the Caspian region that regeneratesnaturally.Seed pretreatment plays an important role in beech reforestation .For this reason the seeds ofthree different provenances; Gilan (Asalem, Nowshahr (Makarood, Gorgan (Cheshmeh gholgholy,across the Caspian region, were collected and after viability test (TTC placed under cold stratification(for 8-19 weeks to overcome dormancy. The results have shown that pregermination treatments haddesirable effects on seed germination. There were significant variations between three origins anddifferent treatment duration and germination characterstics. The Nowshahr and Gilan origins showedmore similarity.

  3. Soil base saturation combines with Beech Bark Disease to influence composition and structure of Sugar Maple-Beech forests in an acid rain-impacted region

    Science.gov (United States)

    Lawrence, Gregory B.; McDonnell, Todd C.; Sullivan, Timothy J.; Dovciak, Martin; Bailey, Scott W.; Antidormi, Michael; Zarfos, Michael R.

    2017-01-01

    Sugar maple, an abundant and highly valued tree species in eastern North America, has experienced decline from soil calcium (Ca) depletion by acidic deposition, while beech, which often coexists with sugar maple, has been afflicted with beech bark disease (BBD) over the same period. To investigate how variations in soil base saturation combine with effects of BBD in influencing stand composition and structure, measurements of soils, canopy, subcanopy, and seedlings were taken in 21 watersheds in the Adirondack region of NY (USA), where sugar maple and beech were the predominant canopy species and base saturation of the upper B horizon ranged from 4.4 to 67%. The base saturation value corresponding to the threshold for Al mobilization (16.8%) helped to define the species composition of canopy trees and seedlings. Canopy vigor and diameter at breast height (DBH) were positively correlated (P soils, soil-Ca depletion and BBD may have created opportunities for gap-exploiting species such as red maple and black cherry, whereas in high-base saturation soils, sugar maple dominated the canopy. Where soils were beginning to recover from acidic deposition effects, sugar maple DBH and basal area increased progressively from 2000 to 2015, whereas for beech, average DBH did not change and basal area did not increase after 2010.

  4. Climate threats on growth of rear-edge European beech peripheral populations in Spain

    Science.gov (United States)

    Dorado-Liñán, I.; Akhmetzyanov, L.; Menzel, A.

    2017-12-01

    European beech ( Fagus sylvatica L.) forests in the Iberian Peninsula are a clear example of a temperate forest tree species at the rear edge of its large distribution area in Europe. The expected drier and warmer climate may alter tree growth and species distribution. Consequently, the peripheral populations will most likely be the most threatened ones. Four peripheral beech forests in the Iberian Peninsula were studied in order to assess the climate factors influencing tree growth for the last six decades. The analyses included an individual tree approach in order to detect not only the changes in the sensitivity to climate but also the potential size-mediated sensitivity to climate. Our results revealed a dominant influence of previous and current year summer on tree growth during the last six decades, although the analysis in two equally long periods unveiled changes and shifts in tree sensitivity to climate. The individual tree approach showed that those changes in tree response to climate are not size dependent in most of the cases. We observed a reduced negative effect of warmer winter temperatures at some sites and a generalized increased influence of previous year climatic conditions on current year tree growth. These results highlight the crucial role played by carryover effects and stored carbohydrates for future tree growth and species persistence.

  5. Partitioning of ecosystem respiration in a beech forest

    DEFF Research Database (Denmark)

    Brændholt, Andreas; Ibrom, Andreas; Larsen, Klaus Steenberg

    2018-01-01

    of Reco in a temperate beech forest at diel, seasonal and annual time scales. Reco was measured by eddy covariance while respiration rates from soil, tree stems and isolated coarse tree roots were measured bi-hourly by an automated closed-chamber system. Soil respiration (Rsoil) was measured in intact...... with the highest respiration rates around 13:00-15:00 CET for Rstem, and the highest respiration seen from 9:00–15:00 for Rroot. In contrast, Rsoil showed the lowest respiration during daytime with no clear difference in the diel pattern between the intact and trenched soil plots. Finally, we calculated annual......Terrestrial ecosystem respiration (Reco) represents a major component of the global carbon cycle. It consists of many sub-components, such as aboveground plant respiration and belowground root and microbial respiration, each of which may respond differently to abiotic factors, and thus to global...

  6. A contribution to the sessile oak site and beech site defining in central Serbia

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    Krstić Milun

    2009-01-01

    Full Text Available The study was carried out in sessile oak forests and beech forests in the region central Serbia. The stands are classified as pure stands with the percentage of other species up to 10% per tree number, mixed forests of sessile oak with other species, and mixed forests of beech with other species, whose percentage does not exceed 50%. Altogether 257 stands were monitored - 202 beech stands and 55 sessile oak stands. By the applied method of defining the local heat potential (Lujić, 1960, modified by Ratknić et al. (2001 and Krstić (2004, 2008, which represents possibility of soil heating without vegetation, were determined. In this way, a scale of 162 possible combinations of local heat potential was obtained, which explains more precisely the dependence of beech stands and sessile oak stands on the topographic conditions. By applying the weighted values of the thermal co-ordinates of aspect and slope (E for each altitudinal belt of 100 m, it was concluded that pure stands have the widest ecological range. Pure beech stands occur at the sites with 34 combinations of thermal co-ordinates E.V=4.6 to 8.12. Pure sessile oak stands occur at the sites with 12 combinations of thermal co-ordinates E.V=5.10 to 8.11. The percentage of mixed beech stands with other broadleaf species is the highest at the sites with the co-ordinate V=10-11 (at the altitudes between 700 and 900 m is about 60 %. Mixed stands of sessile oak and beech are located on the terrains with combinations of thermal co-ordinates E.V=7.9 to 8.12. By using the local heat potential of a region, it can be identified which sites, i.e. which combinations of exposure, slope and altitude belong to the particular tree species. Consequently, a more reliable selection of tree species can be done for the bio-reclamation of barrens and other deforested terrains.

  7. Assortment structure in beech coppice stands in the Crni vrh region

    Directory of Open Access Journals (Sweden)

    Danilović Milorad

    2003-01-01

    Full Text Available Assortment structure in beech coppice stands was studied for the region of Crni vrh. Assortment structure was determined according to the standard (JUS in two ecological units. The study results show that the assortment value structure significantly increases with the increase of tree diameter and that there are no statistically significant differences in assortment structure between the selected ecological units. The dependence of the assortment value structure on tree diameter can be represented by an exponential function. The value percentage of assortments made of stem wood in theoretical crosscutting depending on tree diameter has an increasing tendency, except for the wood for excelsior.

  8. Aphid infestation affecting the biogeochemistry of European beech saplings

    Science.gov (United States)

    Michalzik, B.; Levia, D. F., Jr.; Bischoff, S.; Näthe, K.

    2014-12-01

    Mass outbreaks of herbivore insects are known to perturb the functional properties of forests. However, it is less clear how endemic to moderate aboveground herbivory affects the vertical flow of nutrients from tree canopies to the soil. Here, we report on the effects of low to moderate infestation levels of the woolly beech aphid (Phyllaphis fagi L.) on the nutrient dynamics and hydrology of European beech (Fagus sylvatica L.). In a potted sapling experiment, we followed the vertical dynamics of nutrients via throughfall (TF), stemflow (SF) and litter leachates (LL) collected over ten weeks underneath infested and uninfested control trees. Aphid infestation amplifies the fluxes of K+, Mn2+ and particulate nitrogen (0.45μm aphid abundance by 26 and 16%, respectively. Differences in canopy-derived dissolved nitrogen and carbon compounds, sulfur (S), Ca2+, Mg2+, Na+ were aphid abundance on nutrient dynamics was most notable in TF and SF and diminished in LL.Aphid infestation greatly altered the SF fluxes of DOC, K+, Mn2+, DON and sulfur-species, which were significantly concentrated at the tree base by "funneling" the rainfall through the canopy biomass to the trunk. Normalized to one square meter, water and nutrient fluxes were amplified by a factor of up to 200 compared to TF.Imaging of leaf surfaces by scanning electron microscopy exhibited notable differences of the surface morphology and microbiology of control, lightly infested, and heavily infested leaves. This observation might point to an aphid-mediated alteration of the phyllosphere ecology triggering the microbial uptake of NH4-N and SO4-S and its transformation to particulate N by magnified biomass growth of the phyllosphere microflora, consequently changing the chemical partitioning and temporal availability of nitrogen.

  9. Spontaneous establishment of late successional tree species English oak (.i.Quercus robur./i.) and European beech (.i.Fagus sylvatica./i.) at reclaimed alder plantation and unreclaimed post mining sites

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan; Vobořilová, V.; Janoušová, I.; Kadochová, Štěpánka; Matějíček, L.

    2015-01-01

    Roč. 77, April (2015), s. 1-8 ISSN 0925-8574 Grant - others:GAČR(CZ) GA13-10377S Program:GA Institutional support: RVO:60077344 Keywords : restoration * tree colonisation * succession * disturbance * mycorrhiza * microhabitats Subject RIV: EH - Ecology, Behaviour Impact factor: 2.740, year: 2015

  10. Effect of CO2 enhancement on beech (Fagus sylvatica L. seedling root rot due to Phytophthora plurivora and Phytophthora cactorum

    Directory of Open Access Journals (Sweden)

    Tkaczyk Miłosz

    2014-09-01

    Full Text Available Global climate change is associated with higher concentrations of atmospheric carbon dioxide (CO2. The ongoing changes are likely to have significant, direct or indirect effects on plant diseases caused by many biotic agents such as phytopathogenic fungi. This study results showed that increased CO2 concentration did not stimulate the growth of 1-year-old beech Fagus sylvatica L seedlings but it activated pathogenic Phytophthora species (P. plurivora and P. cactorum which caused significant reduction in the total number of fine roots as well as their length and area. The results of the greenhouse experiment indicated that pathogens once introduced into soil survived in pot soil, became periodically active (in sufficient water conditions and were able to damage beech fine roots. However, the trees mortality was not observed during the first year of experiment. DNA analyses performed on soil and beech tissue proved persistence of introduced Phytophthora isolates.

  11. Desiccation and Mortality Dynamics in Seedlings of Different European Beech (Fagus sylvatica L.) Populations under Extreme Drought Conditions

    Science.gov (United States)

    Bolte, Andreas; Czajkowski, Tomasz; Cocozza, Claudia; Tognetti, Roberto; de Miguel, Marina; Pšidová, Eva; Ditmarová, Ĺubica; Dinca, Lucian; Delzon, Sylvain; Cochard, Hervè; Ræbild, Anders; de Luis, Martin; Cvjetkovic, Branislav; Heiri, Caroline; Müller, Jürgen

    2016-01-01

    European beech (Fagus sylvatica L., hereafter beech), one of the major native tree species in Europe, is known to be drought sensitive. Thus, the identification of critical thresholds of drought impact intensity and duration are of high interest for assessing the adaptive potential of European beech to climate change in its native range. In a common garden experiment with one-year-old seedlings originating from central and marginal origins in six European countries (Denmark, Germany, France, Romania, Bosnia-Herzegovina, and Spain), we applied extreme drought stress and observed desiccation and mortality processes among the different populations and related them to plant water status (predawn water potential, ΨPD) and soil hydraulic traits. For the lethal drought assessment, we used a critical threshold of soil water availability that is reached when 50% mortality in seedling populations occurs (LD50SWA). We found significant population differences in LD50SWA (10.5–17.8%), and mortality dynamics that suggest a genetic difference in drought resistance between populations. The LD50SWA values correlate significantly with the mean growing season precipitation at population origins, but not with the geographic margins of beech range. Thus, beech range marginality may be more due to climatic conditions than to geographic range. The outcome of this study suggests the genetic variation has a major influence on the varying adaptive potential of the investigated populations. PMID:27379105

  12. Some Indicators of Beech Forests Vitality in the Republic of Serbia in Period 2004-2009

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    Radovan Nevenić

    2011-06-01

    Full Text Available Background and Purpose: Forests monitoring is one of the largest forest bio-monitoring systems that is carried out in order to record changes by using the most important environmental parameters. The National Focal Centre for forest monitoring in the Republic of Serbia, within the Institute of Forestry of the Republic of Serbia has been taking an active part in an international program of ICP Forest, with a view to improving its working activities and harmonizing them with other approaches to monitoring forests and forest ecosystems. Material and Methods: In order to determine forest ecosystem processes, it is necessary to carry out detailed research of ecological and socio-economic consequences of forest deterioration and to study the impacts of regional climate changes on forest communities. In the period from 2004 to 2009, observations were performed on 130 sample plots and data necessary for further analysis were collected. These plots are systematically arranged in either a 16x16 km or a 4 x 4 km grid system. The main parameters assessed on the sample plots are the degree of defoliation and discolouration as well as the extent of damage. A comparative analysis of the data obtained in this period will provide a better insight into the present state of beech forests in Serbia as well the effects of defoliation and discolouration trends. Results and Conclusion: Beech is the most common broadleaved tree species on the Level I sample plots. Its health state is the result of adverse effects of complex factors of abiotic and biotic origin (i.e. effects of both living organisms and complex natural processes within the beech forests habitats. This paper presents some indicators of beech forest vitality whose occurrence show certain regularity and which can be interpreted as a trend. The annual values of the health state elements and the fluctuations of these parameters from year to year present important indicators of vitality of beech forests in

  13. Beech and spruce under the influence of electromagnetic radiation by radar

    International Nuclear Information System (INIS)

    Götz, G.; Matyssek, R.; Käs, G.

    2001-01-01

    Throughout a three-year study period beech and spruce trees were examined for potential effects of electromagnetic radiation by radar on the morphological and physiological performance at the crown level. No effects of radar on photosynthesis, transpiration, stomatal regulation as well as twig and foliage differentiation were found in late summer after seasonal exposure to this kind of radiation, when comparing radar-exposed with shielded crown parts. Adverse effects caused by radar on forest trees appear to be unlikely on a short-term scale, given conditions similar to those of this case study [de

  14. Safeguarding saproxylic fungal biodiversity in Apennine beech forest priority habitats

    Science.gov (United States)

    Maggi, Oriana; Lunghini, Dario; Pecoraro, Lorenzo; Sabatini, Francesco Maria; Persiani, Anna Maria

    2015-04-01

    The FAGUS LIFE Project (LIFE11/NAT/IT/135) targets two European priority habitats, i.e. Habitat 9210* Apennine beech forests with Taxus and Ilex, and Habitat 9220* Apennine beech forests with Abies alba, within two National Parks: Cilento, Vallo di Diano and Alburni; Gran Sasso and Monti della Laga. The current limited distribution of the target habitats is also due to the impact of human activities on forest systems, such as harvesting and grazing. The FAGUS project aims at developing and testing management strategies able to integrate the conservation of priority forest habitats (9210* and 9220*) and the sustainable use of forest resources. In order to assess the responses to different management treatments the BACI monitoring design (Before-After, Control-Intervention) has been applied on forest structure and diversity of focus taxa before and after experimental harvesting treatments. Conventional management of Apennine beech forests impacts a wealth of taxonomic groups, such as saproxylic beetles and fungi, which are threatened throughout Europe by the lack of deadwood and of senescing trees, and by the homogeneous structure of managed forests. Deadwood has been denoted as the most important manageable habitat for biodiversity in forests not only for supporting a wide diversity of organisms, but also for playing a prominent role in several ecological processes, creating the basis for the cycling of photosynthetic energy, carbon, and nutrients stored in woody material. Especially fungi can be regarded as key group for understanding and managing biodiversity associated with decaying wood. The before-intervention field sampling was carried out in Autumn 2013 in 33 monitoring plots across the two national Parks. The occurrence at plot level of both Ascomycota and Basidiomycota sporocarps was surveyed. All standing and downed deadwood with a minimum diameter of 10 cm was sampled for sporocarps larger than 1 mm, and information on decay class and fungal morphogroups

  15. Radial variations in cation exchange capacity and base saturation rate in the wood of pedunculate oak and European beech

    Energy Technology Data Exchange (ETDEWEB)

    Herbauts, J.; Penninckx, V.; Gruber, W.; Meerts, P. [Universite Libre de Bruxelles, Laboratoire de genetique et d' ecologie vegetales, Brussels (Belgium)

    2002-10-01

    Visual observation of pedunculate oak trees and European beech trees in a mixed forest stand in the Belgian Ardennes revealed decreasing cation concentration profiles in wood. In order to determine whether these profiles are attributable to endogenous factors or to decreased availability of cations in the soil, radial profiles of water-soluble, exchangeable and total cations were investigated. Cation exchange capacity of wood was also determined. Results showed wood cation exchange capacity to decrease from pith to bark in European beech and from pith to outer heartwood in pedunculate oak. Decreasing profiles of exchangeable calcium and magnesium in peduncular oak and exchangeable calcium in European beech were found to be strongly constrained by cation exchange capacity, and thus not related to environmental change. Base cation saturation rate showed no consistent radial change in either species. It was concluded that the results did not provide convincing evidence to attribute the decrease in divalent cation concentration in pedunculate oak and European beech in this location to be due to atmospheric pollution. 42 refs., 1 tab., 4 figs.

  16. A new approach in the monitoring of the phytosanitary conditions of forests: the case of oak and beech stands in the Sicilian Regional Parks

    Directory of Open Access Journals (Sweden)

    Cinzia Rizza

    2016-10-01

    Full Text Available The objective of this study was to investigate the health conditions of oak and beech stands in the three Regional Parks of Sicily (Etna, Madonie and Nebrodi. A total of 81 sampling areas were investigated, 54 in oak stands and 27 in beech stands. The phytosanitary conditions of each tree within the respective sampling area was expressed with a synthetic index namely phytosanitary class (PC. Oak stands showed severe symptoms of decline, with 85% of the sampling areas including symptomatic trees. In general, beech stands were in better condition, with the exception of Nebrodi Park, where trees showed severe symptoms of decline. On oak trees, infections of fungal pathogens were also observed, including Biscogniauxia mediterranea, Polyporus sp., Fistulina hepatica, Mycrosphaera alphitoides and Armillaria sp. By contrast, on beech trees Biscogniauxia nummularia, Fomes fomentarius and Neonectria radicicola were recognized. Furthermore, twenty-two permanent sampling areas were delimited with the aim of monitoring regularly the health conditions of forests in these three parks.

  17. Evaluating management regimes for European beech forests using dynamic programming

    Directory of Open Access Journals (Sweden)

    Juan Torres Rojo

    2014-12-01

    Full Text Available Aim of study: This contribution describes a systematic search method for identifying optimum thinning regimes for beech forests (Fagus sylvatica L. by using a combination of optimization heuristics and a simple whole stand growth prediction model. Area of study: Data to build the model come from standard and management forest inventories as well as yield tables from the Northern and Western part of Germany and from southern and central Denmark.Material and Methods: Growth projections are made from equations to project basal area and top height.  The remaining stand variables are recovered from additional equations fitted from forest inventory data or acquired from other authors.  Mortality is estimated through an algorithm based on the maximum density line. The optimization routine uses a two-state dynamic programming model. Thinning type is defined by the NG index, which describes the ratio of the proportion of removed trees and basal area with respect to the same proportion  before thinning. Main results: Growth equations fitted from inventory data show high goodness of fit with R2 values larger than 0.85 and high significance levels for the parameter estimates. The mortality algorithm converges quickly providing mortality estimates within the expected range.Research Highlights: The combination of a simple growth and yield model within a Dynamic Programming framework in conjunction with NG values as indicators of thinning type yield good estimates of practical thinning schedules compared to thinning recommendations provided by diverse authors.Keywords: beech (Fagus sylvatica L.; NG ratio; thinning optimization; growth and yield simulation; mortality.

  18. Beech forests (order Fagetalia sylvaticae Pawlowski 1928) in Serbia

    OpenAIRE

    Branko Karadžić

    2018-01-01

    Beech forests occupy considerable areas in Serbia. The principal aims of this research were to detect variability patterns and determine biodiversity components in Serbian beech forests. The K-means clustering of a data set comprising 270 relevés and more than 500 species revealed seven ecologically interpretable groups of beech forests in Serbia. The groups are presented in a synoptic table, with calculation of diagnostic species. Canonical correspondence analysis indicates that ...

  19. Beech forests (order Fagetalia sylvaticae Pawlowski 1928 in Serbia

    Directory of Open Access Journals (Sweden)

    Branko Karadžić

    2018-02-01

    Full Text Available Beech forests occupy considerable areas in Serbia. The principal aims of this research were to detect variability patterns and determine biodiversity components in Serbian beech forests. The K-means clustering of a data set comprising 270 relevés and more than 500 species revealed seven ecologically interpretable groups of beech forests in Serbia. The groups are presented in a synoptic table, with calculation of diagnostic species. Canonical correspondence analysis indicates that the altitudinal gradient is the main factor affecting diversification of the investigated forests. Species richness and alpha diversity are greatest in beech forests of ravine habitats

  20. Major Changes in Growth Rate and Growth Variability of Beech (Fagus sylvatica L. Related to Soil Alteration and Climate Change in Belgium

    Directory of Open Access Journals (Sweden)

    Nicolas Latte

    2016-08-01

    Full Text Available Global change—particularly climate change, forest management, and atmospheric deposition—has significantly altered forest growing conditions in Europe. The influences of these changes on beech growth (Fagus sylvatica L. were investigated for the past 80 years in Belgium, using non-linear mixed effects models on ring-width chronologies of 149 mature and dominant beech trees (87–186 years old. The effects of the developmental stage (i.e., increasing tree size were filtered out in order to focus on time-dependent growth changes. Beech radial growth was divided into a low-frequency signal (=growth rate, mainly influenced by forest management and atmospheric deposition, and into a high-frequency variability (≈mean sensitivity, mainly influenced by climate change. Between 1930 and 2008, major long-term and time-dependent changes were highlighted. The beech growth rate has decreased by about 38% since the 1950–1960s, and growth variability has increased by about 45% since the 1970–1980s. Our results indicate that (1 before the 1980s, beech growth rate was not predominantly impacted by climate change but rather by soil alteration (i.e., soil compaction and/or nitrogen deposition; and (2 since the 1980s, climate change induced more frequent and intense yearly growth reductions that amplified the growth rate decrease. The highlighted changes were similar in the two ecoregions of Belgium, although more pronounced in the lowlands than in the uplands.

  1. Edaphic potentials of beech forests on Brezovica

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    Knežević Milan

    2002-01-01

    Full Text Available The study deals with the soils in the montane beech forest (Fagetum moesiacae montanum Jov. 53 in the management units "Južni Kuèaj II" and "Bogovina I", on the mountain massif Brezovica. Soil genesis in the beech forests of Brezovica, along with vegetation and relief, was affected by the character of parent rock. The study soils occur over two types of bedrock: limestone and argilloschist The soil types and sub-types are defined based on the profile morphology, parent rock and pedogenetic processes Two types of soil were analysed on limestone: black earth (calcomelanosol and brown soil (calcocambisol. Two sub-types of black earth were defined: organomineral and brownised. There are two varieties of organomineral black earth: colluvial and lithic. Also two sub-types of brown soils were defined and: typical and illimerised. The soils on limestone are characterised by great spatial variability. Different combinations of soil formations occur on a small area. Soil combinations consist of two or three development phases, the most represented of which are the following: organomineral black earth - brownised black earth; organomineral black earth - brownised black earth - typical brown soil; typical brown soil - illimerised soil Typical brown soil is formed on argilloschists and it occurs in two forms: medium deep, medium skeletal acid brown soil and deep, poorly skeletal acid brown soil The most productive sites of the montane beech forest on Brezovica are deep acid brown soils and the soil combination: typical brown soil - illimerised soil on limestone.

  2. Spatial patterns and broad-scale weather cues of beech mast seeding in Europe.

    Science.gov (United States)

    Vacchiano, Giorgio; Hacket-Pain, Andrew; Turco, Marco; Motta, Renzo; Maringer, Janet; Conedera, Marco; Drobyshev, Igor; Ascoli, Davide

    2017-07-01

    Mast seeding is a crucial population process in many tree species, but its spatio-temporal patterns and drivers at the continental scale remain unknown . Using a large dataset (8000 masting observations across Europe for years 1950-2014) we analysed the spatial pattern of masting across the entire geographical range of European beech, how it is influenced by precipitation, temperature and drought, and the temporal and spatial stability of masting-weather correlations. Beech masting exhibited a general distance-dependent synchronicity and a pattern structured in three broad geographical groups consistent with continental climate regimes. Spearman's correlations and logistic regression revealed a general pattern of beech masting correlating negatively with temperature in the summer 2 yr before masting, and positively with summer temperature 1 yr before masting (i.e. 2T model). The temperature difference between the two previous summers (DeltaT model) was also a good predictor. Moving correlation analysis applied to the longest eight chronologies (74-114 yr) revealed stable correlations between temperature and masting, confirming consistency in weather cues across space and time. These results confirm widespread dependency of masting on temperature and lend robustness to the attempts to reconstruct and predict mast years using temperature data. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  3. Dead wood in European beech (Fagus sylvatica) forest reserves

    NARCIS (Netherlands)

    Christensen, M.; Hahn, K.; Mountford, E.P.; Ódor, P.; Standovár, T.; Rozenbergar, D.; Diaci, J.; Wijdeven, S.M.J.; Meyer, P.; Winter, S.; Vrska, T.

    2005-01-01

    Data were analysed on the volume of dead wood in 86 beech forest reserves, covering most of the range of European beech forests. The mean volume was 130 m3/ha and the variation among reserves was high, ranging from almost nil to 550 m3/ha. The volume depended significantly on forest type, age since

  4. Nitrous oxide emissions from a beech forest floor measured by eddy covariance and soil enclosure techniques

    DEFF Research Database (Denmark)

    Pihlatie, M.; Rinne, J.; Ambus, P.

    2005-01-01

    Spring time nitrous oxide (N2O) emissions from an old beech (Fagus sylvatica L.) forest were measured with eddy covariance (EC) and chamber techniques. The aim was to obtain information on the spatial and temporal variability in N2O emissions and link the emissions to soil environmental parameters...... the first week of May when the trees were leafing and the soil moisture content was at its highest. If chamber techniques are used to estimate ecosystem level N2O emissions from forest soils, placement of the chambers should be considered carefully to cover the spatial variability in the soil N2O emissions...

  5. Climate Change Impairs Nitrogen Cycling in European Beech Forests.

    Science.gov (United States)

    Dannenmann, Michael; Bimüller, Carolin; Gschwendtner, Silvia; Leberecht, Martin; Tejedor, Javier; Bilela, Silvija; Gasche, Rainer; Hanewinkel, Marc; Baltensweiler, Andri; Kögel-Knabner, Ingrid; Polle, Andrea; Schloter, Michael; Simon, Judy; Rennenberg, Heinz

    2016-01-01

    European beech forests growing on marginal calcareous soils have been proposed to be vulnerable to decreased soil water availability. This could result in a large-scale loss of ecological services and economical value in a changing climate. In order to evaluate the potential consequences of this drought-sensitivity, we investigated potential species range shifts for European beech forests on calcareous soil in the 21st century by statistical species range distribution modelling for present day and projected future climate conditions. We found a dramatic decline by 78% until 2080. Still the physiological or biogeochemical mechanisms underlying the drought sensitivity of European beech are largely unknown. Drought sensitivity of beech is commonly attributed to plant physiological constraints. Furthermore, it has also been proposed that reduced soil water availability could promote nitrogen (N) limitation of European beech due to impaired microbial N cycling in soil, but this hypothesis has not yet been tested. Hence we investigated the influence of simulated climate change (increased temperatures, reduced soil water availability) on soil gross microbial N turnover and plant N uptake in the beech-soil interface of a typical mountainous beech forest stocking on calcareous soil in SW Germany. For this purpose, triple 15N isotope labelling of intact beech seedling-soil-microbe systems was combined with a space-for-time climate change experiment. We found that nitrate was the dominant N source for beech natural regeneration. Reduced soil water content caused a persistent decline of ammonia oxidizing bacteria and therefore, a massive attenuation of gross nitrification rates and nitrate availability in the soil. Consequently, nitrate and total N uptake of beech seedlings were strongly reduced so that impaired growth of beech seedlings was observed already after one year of exposure to simulated climatic change. We conclude that the N cycle in this ecosystem and here

  6. Climate Change Impairs Nitrogen Cycling in European Beech Forests.

    Directory of Open Access Journals (Sweden)

    Michael Dannenmann

    Full Text Available European beech forests growing on marginal calcareous soils have been proposed to be vulnerable to decreased soil water availability. This could result in a large-scale loss of ecological services and economical value in a changing climate. In order to evaluate the potential consequences of this drought-sensitivity, we investigated potential species range shifts for European beech forests on calcareous soil in the 21st century by statistical species range distribution modelling for present day and projected future climate conditions. We found a dramatic decline by 78% until 2080. Still the physiological or biogeochemical mechanisms underlying the drought sensitivity of European beech are largely unknown. Drought sensitivity of beech is commonly attributed to plant physiological constraints. Furthermore, it has also been proposed that reduced soil water availability could promote nitrogen (N limitation of European beech due to impaired microbial N cycling in soil, but this hypothesis has not yet been tested. Hence we investigated the influence of simulated climate change (increased temperatures, reduced soil water availability on soil gross microbial N turnover and plant N uptake in the beech-soil interface of a typical mountainous beech forest stocking on calcareous soil in SW Germany. For this purpose, triple 15N isotope labelling of intact beech seedling-soil-microbe systems was combined with a space-for-time climate change experiment. We found that nitrate was the dominant N source for beech natural regeneration. Reduced soil water content caused a persistent decline of ammonia oxidizing bacteria and therefore, a massive attenuation of gross nitrification rates and nitrate availability in the soil. Consequently, nitrate and total N uptake of beech seedlings were strongly reduced so that impaired growth of beech seedlings was observed already after one year of exposure to simulated climatic change. We conclude that the N cycle in this

  7. Ecological species group—Environmental factors relationships in unharvested beech forests in the north of Iran

    Science.gov (United States)

    Mohammad Naghi Adel; Hassan Pourbabaei; Daniel C. Dey

    2014-01-01

    Beech forests are the richest forest community in Iran because they are both economically and environmentally valuable. The greatest forest volume occurs in Iran's beech forests. Forests dominated by oriental beech (Fagus orientalis Lipskey) cover about 565,000 ha and represent the total area of indigenous forests in Guilan Province. A system for classifying beech...

  8. Use of microsatellite markers in an American beech (Fagus grandifolia) population and paternity testing

    Science.gov (United States)

    Jennifer Koch; Dave Carey; M.E. Mason

    2010-01-01

    Cross-species amplification of six microsatellite markers from European beech (Fagus sylvatica Linn) and nine markers from Japanese beech (Fagus crenata Blume) was tested in American beech (Fagus grandifolia Ehrh.). Three microsatellites from each species were successfully adapted for use in American beech...

  9. Isoprenoid emission response to changing light conditions of English oak, European beech and Norway spruce

    Science.gov (United States)

    van Meeningen, Ylva; Schurgers, Guy; Rinnan, Riikka; Holst, Thomas

    2017-09-01

    Light is an important environmental factor controlling biogenic volatile organic compound (BVOC) emissions, but in natural conditions its impact is hard to separate from other influential factors such as temperature. We studied the light response of foliar BVOC emissions, photosynthesis and stomatal conductance on three common European tree species, namely English oak (Quercus robur), European beech (Fagus sylvatica) and two provenances of Norway spruce (Picea abies) in Taastrup, Denmark. Leaf scale measurements were performed on the lowest positioned branches of the tree in July 2015. Light intensity was increased in four steps (0, 500, 1000 and 1500 µmol m-2 s-1), whilst other chamber conditions such as temperature, humidity and CO2 levels were fixed. Whereas the emission rate differed between individuals of the same species, the relative contributions of compounds to the total isoprenoid emission remained similar. Whilst some compounds were species specific, the compounds α-pinene, camphene, 3-carene, limonene and eucalyptol were emitted by all of the measured tree species. Some compounds, like isoprene and sabinene, showed an increasing emission response with increasing light intensity, whereas other compounds, like camphene, had no significant emission response to light for most of the measured trees. English oak and European beech showed high light-dependent emission fractions from isoprene and sabinene, but other emitted compounds were light independent. For the two provenances of Norway spruce, the compounds α-pinene, 3-carene and eucalyptol showed high light-dependent fractions for many of the measured trees. This study highlights differences between compound emissions in their response to a change in light and a possible light independence for certain compounds, which might be valid for a wider range of tree species. This information could be of importance when improving emission models and to further emphasize the discussion regarding light or

  10. Beech carbon productivity as driver of ectomycorrhizal abundance and diversity.

    Science.gov (United States)

    Druebert, Christine; Lang, Christa; Valtanen, Kerttu; Polle, Andrea

    2009-08-01

    We tested the hypothesis that carbon productivity of beech (Fagus sylvatica) controls ectomycorrhizal colonization, diversity and community structures. Carbon productivity was limited by long-term shading or by girdling. The trees were grown in compost soil to avoid nutrient deficiencies. Despite severe limitation in photosynthesis and biomass production by shading, the concentrations of carbohydrates in roots were unaffected by the light level. Shade-acclimated plants were only 10% and sun-acclimated plants were 74% colonized by ectomycorrhiza. EM diversity was higher on roots with high than at roots with low mycorrhizal colonization. Evenness was unaffected by any treatment. Low mycorrhizal colonization had no negative effects on plant mineral nutrition. In girdled plants mycorrhizal colonization and diversity were retained although (14)C-leaf feeding showed almost complete disruption of carbon transport from leaves to roots. Carbohydrate storage pools in roots decreased upon girdling. Our results show that plant carbon productivity was the reason for and not the result of high ectomycorrhizal diversity. We suggest that ectomycorrhiza can be supplied by two carbon routes: recent photosynthate and stored carbohydrates. Storage pools may be important for ectomycorrhizal survival when photoassimilates were unavailable, probably feeding preferentially less carbon demanding EM species as shifts in community composition were found.

  11. Low Light Availability Associated with American Beech Is the Main Factor for Reduced Sugar Maple Seedling Survival and Growth Rates in a Hardwood Forest of Southern Quebec

    Directory of Open Access Journals (Sweden)

    Alexandre Collin

    2017-10-01

    Full Text Available Several recent studies have reported a marked increase in American beech dominance (Fagus grandifolia Ehrh. relative to sugar maple (Acer saccharum Marsh. in late successional forests of North America. However, many factors have been proposed to explain this sudden shift in tree species composition. We investigated the microsite factors responsible for maple regeneration failure under maple-beech stands, focusing on both light availability and soil conditions. The survival and growth of maple seedlings planted in the natural soil and in pots with enriched soil were monitored for two years, as well as foliar nutrition and herbivory damages of natural seedlings. The results indicate that low light availability associated with the presence of beech is the primary factor leading to maple regeneration failures. Soil nutrient availability and foliar nutrition of natural seedlings did not differ between forest types. Yet, the results indicate that factors such as allelopathy and preferential herbivory on maple seedlings under beech could be superimposed effects that hinder maple regeneration. Under similar forests, a control of beech sapling abundance in the understory followed by selection cutting could be one way to promote and maintain maple populations in the longer term.

  12. Effect of the density of transplants in reforestation on the morphological quality of the above-ground part of European beech (Fagus sylvatica L. six years after planting

    Directory of Open Access Journals (Sweden)

    Kateřina Houšková

    2013-01-01

    Full Text Available Quality of the above-ground part of European beech planted at different densities and spacing patterns for the purpose of artificial forest regeneration was monitored 3, 4 and 6 years after planting. The initial numbers of beech transplants were 5,000 pcs.ha−1, 10,000 pcs.ha−1, 15,000 pcs.ha−1 and 20,000 pcs.ha−1. The spacing pattern of transplants was either square or rectangular nearly in all variants: 1.4 × 1.4 m, 2 × 1 m, 1 × 1 m, 0.8 × 0.8 m, 1 ×0.65 m, 0.7 × 0.7 m and 1 × 0.5 m. Conclusions following out from the research are as follows: 1. neither the chosen density of transplants nor their spacing pattern had an essential influence on the after-planting loss or damage of trees; 2. through the planting of larger-diameter transplants it is possible to achieve canopy closure more rapidly as well as faster growth of the plantation; these beech plants keep the edge in growth and quality even 6 years after planting; 3. the higher is the beech plantation density, the less individuals occur in such a plantation with inappropriate stem form; 4. beech plants of the worst quality were found on plots with the lowest initial density of transplants (5,000 and 10,000 pcs.ha−1, yet the number of promising trees was sufficient even there. Thus, none of the experimental numbers of transplants per hectare or spacing arrangements of the European beech transplants can be claimed as inappropriate; however, further monitoring of the plots is necessary.

  13. Resilient Leaf Physiological Response of European Beech (Fagus sylvatica L. to Summer Drought and Drought Release

    Directory of Open Access Journals (Sweden)

    Ellen E. Pflug

    2018-02-01

    Full Text Available Drought is a major environmental constraint to trees, causing severe stress and thus adversely affecting their functional integrity. European beech (Fagus sylvatica L. is a key species in mesic forests that is commonly expected to suffer in a future climate with more intense and frequent droughts. Here, we assessed the seasonal response of leaf physiological characteristics of beech saplings to drought and drought release to investigate their potential to recover from the imposed stress and overcome previous limitations. Saplings were transplanted to model ecosystems and exposed to a simulated summer drought. Pre-dawn water potentials (ψpd, stomatal conductance (gS, intercellular CO2 concentration (ci, net-photosynthesis (AN, PSII chlorophyll fluorescence (PItot, non-structural carbohydrate concentrations (NSC; soluble sugars, starch and carbon isotope signatures were measured in leaves throughout the growing season. Pre-dawn water potentials (ψpd, gS, ci, AN, and PItot decreased as drought progressed, and the concentration of soluble sugars increased at the expense of starch. Carbon isotopes in soluble sugars (δ13CS showed a distinct increase under drought, suggesting, together with decreased ci, stomatal limitation of AN. Drought effects on ψpd, ci, and NSC disappeared shortly after re-watering, while full recovery of gS, AN, and PItot was delayed by 1 week. The fast recovery of NSC was reflected by a rapid decay of the drought signal in δ13C values, indicating a rapid turnover of assimilates and a reactivation of carbon metabolism. After recovery, the previously drought-exposed saplings showed a stimulation of AN and a trend toward elevated starch concentrations, which counteracted the previous drought limitations. Overall, our results suggest that the internal water relations of beech saplings and the physiological activity of leaves are restored rapidly after drought release. In the case of AN, stimulation after drought may partially

  14. Structure, electrical resistivity, and thermal conductivity of beech wood biocarbon produced at carbonization temperatures below 1000°C

    Science.gov (United States)

    Parfen'eva, L. S.; Orlova, T. S.; Kartenko, N. F.; Smirnov, B. I.; Smirnov, I. A.; Misiorek, H.; Jezowski, A.; Muha, J.; Vera, M. C.

    2011-11-01

    This paper reports on measurements of the thermal conductivity κ and the electrical resistivity ρ in the temperature range 5-300 K, and, at 300 K, on X-ray diffraction studies of high-porosity (with a channel pore volume fraction of ˜47 vol %) of the beech wood biocarbon prepared by pyrolysis (carbonization) of tree wood in an argon flow at the carbonization temperature T carb = 800°C. It has been shown that the biocarbon template of the samples studied represents essentially a nanocomposite made up of amorphous carbon and nanocrystallites—"graphite fragments" and graphene layers. The sizes of the nanocrystallites forming these nanocomposites have been determined. The dependences ρ( T) and κ( T) have been measured for the samples cut along and perpendicular to the tree growth direction, thus permitting determination of the magnitude of the anisotropy of these parameters. The dependences ρ( T) and κ( T), which have been obtained for beech biocarbon samples prepared at T carb = 800°C, are compared with the data amassed by us earlier for samples fabricated at T carb = 1000 and 2400°C. The magnitude and temperature dependence of the phonon thermal conductivity of the nanocomposite making up the beech biocarbon template at T carb = 800°C have been found.

  15. Impact of windstorm on a community of centipedes (Chilopoda) in a beech forest in Western Poland.

    Science.gov (United States)

    Leśniewska, Małgorzata; Skwierczyński, Filip

    2018-01-01

    The study was carried out in the years 2016-2017, five years after a windstorm which destroyed 1/3 of the protected beech forest area in the west of Poland. The community of centipedes in the area affected by the windstorm was depleted in terms of the species richness, diversity, and population density. The dominance structures were shortened and the species composition was rebuilt. The areas that proved to be the richest in terms of species richness and diversity among the sites affected by the windstorm were the one where windfallen trees were left and the other where beech trees had been planted by humans. In total, the quantitative and qualitative samples collected four times throughout a year featured 608 specimens from 11 species of two centipede orders - Lithobiomorpha and Geophilomorpha. Lithobius curtipes and L. forficatus were found in all of the investigated areas. L. pelidnus and L. piceus were captured at control sites exclusively. Only one species - L. erythrocephalus was found solely at the damaged site. The most numerous and most frequently found species in the community were L. curtipes , L. mutabilis , and Strigamia acuminata respectively. Although windstorms are natural phenomena their consequences may lead to significant changes in the community of the investigated soil animals. The importance of coarse woody debris, significantly contributing to the improvement and maintenance of species richness and diversity of Chilopoda, has once again been confirmed.

  16. The effects of habitat degradation on metacommunity structure of wood-inhabiting fungi in European beech forests

    DEFF Research Database (Denmark)

    Halme, Panu; Ódor, Péter; Christensen, Morten

    2013-01-01

    on biodiversity, but actual knowledge of the conservation efficiency is limited, especially for recent reserves. The structure of ecological communities is often described with measures of nestedness, beta diversity and similarity between communities. We studied whether these measures differ among forest reserves...... with different management histories. For this purpose, we used a large data set of wood-inhabiting fungi collected from dead beech trees in European beech-dominated forest reserves. The structure of fungal assemblages showed high beta diversity, while nestedness and similarity was low. During the decomposition...... extirpated specialized species from the local species pools in managed sites, and resulted in more homogeneous communities in managed sites. It is alarming that community structure is affected the most in the latest decay stages where the decay process turns the dead wood into litter, and which is thus...

  17. Allocation of recent photoassimilates in mature European beech and Norway spruce - seasonal variability and responses to experimentally increased tropospheric O3 concentration and long-term drought

    Science.gov (United States)

    Grams, Thorsten

    2016-04-01

    This contribution summarizes a series of C allocation studies in maturing European beech and Norway spruce trees at Kranzberg Forest, located in southern Germany. Study objects are 60 to 70 year old trees, readily accessible via scaffoldings and canopy crane. Allocation of recently fixed photoassimilates is assessed either by conventional branch-bag labelling with 99 atom% 13CO2 or whole-tree labeling using 13C-depleted CO2 (isoFACE system). While labeling in branch bags, employed for few hours only, focused on phloem functionality in particular under long-term drought, C labeling of whole tree canopies was employed for up to 20 days, studying allocation of recent photoassimilates from the canopy along branches and stems to roots and soils below ground. In all experiments, dynamics of C allocation were mostly pursued assessing carbon isotopic composition of CO2 efflux from woody tissues which typically reflected isotopic composition of phloem sugars. Effects of severe and long-term summer drought are assessed in an ongoing experiment with roughly 100 trees assigned to a total of 12 plots (kroof.wzw.tum.de). Precipitation throughfall was completely excluded since early spring, resulting in pre-dawn leaf water potentials of both beech and spruce up to -2.2 MPa. The hypothesis was tested that long-term drought affects allocation of recently fixed C to branches and phloem functionality. In the annual course under unstressed conditions, phloem transport speed from the canopy to the stem (breast height) was double in beech compared to spruce, with highest transport velocities in early summer (about 0.51 and 0.26 m/h) and lowest in spring (0.26 and 0.12 m/h for beech and spruce, respectively). After leaf flush in spring, growth respiration of beech trunks was largely supplied by C stores. Recent photoassimilates supplied beech stem growth in early summer and refilled C stores in late summer, whereas seasonality was less pronounced in spruce. The hypothesis that growth

  18. Disintegration of beech wood char during thermal conversion

    DEFF Research Database (Denmark)

    Hindsgaul, Claus

    In the present work the processes occurring in the structures of slowly pyrolysed beech wood char during thermal gasification have been investigated. Emphasis was put on physical changes and gas transport properties during conversion. The highly anisotropic structure of wood was preserved in its...... differences of 3—4 orders of magnitude between the longitudinal and other directions in freshly pyrolysed beech wood char. Diffusion in the longitudinal direction of the beech wood char before gasification corresponded to direct, unobstructed diffusion through its vessel cells. Radial and tangential diffusion...... were limited by Knudsen diffusion through the pits in the wood cell walls for degrees of conversion by gasification up to at least 0.5. A computer model of slab gasification based on the diffusion measurements successfully predicted the mass loss rate during diffusion-limited gasification of beech wood...

  19. Optimization of thinning technology in beech coppice stands in Crni Vrh region

    Directory of Open Access Journals (Sweden)

    Bajić Vojislav

    2004-01-01

    Full Text Available The application of rationalized thinning technology in beech coppice stands was studied. Three basic methods of thinning: schematic, selection and combined method were analyzed. In the framework of each of the above thinning methods, different thinning varieties were designed, differing by the degree of crosscutting, width of gathering lines and their distance. The applied method of felling and crosscutting is the whole tree method or log method, and the form of work organization (1M+1R. The felling and crosscutting are characterized by two key work operations: directed felling and manual collection of the felled wood material. Manual collection is made significantly easier by the correct selection of tree felling direction which in turn affects significantly the rationalization of the entire thinning process.

  20. Effect of Altitude and Aspect on Wood-Water Relations of Beech (Fagus orientalis Lipsky. Wood

    Directory of Open Access Journals (Sweden)

    Elif Topaloğlu

    2013-11-01

    Full Text Available Effects of altitude and aspect on wood-water relations in Oriental beech (Fagus orientalis Lipsky. were studied. Study area divided into five altitude steps and two aspect groups, total of 20 trees were cut off. In order to determine the wood-water relations; volume density value, fiber saturation point, maximum moisture content, and shrinkage and swelling percentages were determined. According to results, with 95% significance level (p<0,05, altitude affects volume density value, shrinkage and swelling percentages, fiber saturation point and maximum moisture content; aspect affects volume density value, tangential and radial shrinkage percentages, volumetric shrinkage percentage, tangential and longitudinal swelling percentages, fiber saturation point and maximum moisture content while it has no effect on longitudinal shrinkage percentage, radial and volumetric swelling percentages. Results demonstrated that northern aspect and first altitude step has the lowest values, thus, this aspect and altitude step making a suitable place for this tree species to be used as solid wood.

  1. Beech bark necrosis: partitioning the environmental and spatial variation of the damage severity in Central and South-Eastern Europe

    Directory of Open Access Journals (Sweden)

    Benjamín Jarčuška

    2013-11-01

    Full Text Available The beech bark necrosis (BBN infestation severity of Europeanbeech (Fagus sylvatica L. was assessed in regions of Central (CE andSouth-Eastern Europe (SE. Altogether more than 10,000 trees were sampled at 114 sites. Using variation partitioning method, we examined the pure and shared effects of stand, site, climate and spatial sets of variables on mean BBN severity. Our rating included (i the whole stand, (ii tree social status classes, (iii canopy (C and (iv understory (U trees separately. We found that C trees were less affected by BBN than sub-canopy and U trees in both regions. There were found inter-regional differences in amount of explained variability (25.4–73.9% for whole stand BBN and in the sensitivity of C and U trees to the environmental gradients. The analysisrevealed that the climate and spatial variables followed by stand variables had the largest marginal effects on mean BBN severity in all models, while the site set of variables had the weakest one. More than half of the explained variation was shared among four sets of variables in SE, contrary to CE. Except to U trees in SE, the effect of climate – pure or spatially structured – remained the highest also after partitioning of variance; more in SE than in CE. Taking into account positive association between mean annual temperature and mean BBN severity in C trees in SE, reinforced negative effect of climate change on the necrosis might be expected to be more seriousmainly in low situated beech forests there. Promoting the tree speciesdiversity in forested areas with higher incidence of beech bark necrosis, i.e. in low altitudes in SE, could reduce the susceptibility of forests to the necrosis at regional level in the future. For better understanding of the relative importance of environmental and spatial variables on BBN severity, further research performed on finer spatial scale (extent and grain is necessary, along with accounting for pathogens involved in the

  2. Gap Dynamics and Structure of Two Old-Growth Beech Forest Remnants in Slovenia

    Science.gov (United States)

    Rugani, Tihomir; Diaci, Jurij; Hladnik, David

    2013-01-01

    Context Due to a long history of intensive forest exploitation, few European beech (Fagus sylvatica L.) old-growth forests have been preserved in Europe. Material and Methods We studied two beech forest reserves in southern Slovenia. We examined the structural characteristics of the two forest reserves based on data from sample plots and complete inventory obtained from four previous forest management plans. To gain a better understanding of disturbance dynamics, we used aerial imagery to study the characteristics of canopy gaps over an 11-year period in the Kopa forest reserve and a 20-year period in the Gorjanci forest reserve. Results The results suggest that these forests are structurally heterogeneous over small spatial scales. Gap size analysis showed that gaps smaller than 500 m2 are the dominant driving force of stand development. The percentage of forest area in canopy gaps ranged from 3.2 to 4.5% in the Kopa forest reserve and from 9.1 to 10.6% in the Gorjanci forest reserve. These forests exhibit relatively high annual rates of coverage by newly established (0.15 and 0.25%) and closed (0.08 and 0.16%) canopy gaps. New gap formation is dependant on senescent trees located throughout the reserve. Conclusion We conclude that these stands are not even-sized, but rather unevenly structured. This is due to the fact that the disturbance regime is characterized by low intensity, small-scale disturbances. PMID:23308115

  3. Carbon cycling along a gradient of beech bark disease impact in the Catskill Mountains, New York

    Energy Technology Data Exchange (ETDEWEB)

    Hancock, J.E.; Arthur, M.A. [Kentucky Univ., Lexington, KY (United States). Dept. of Forestry; Weathers, K.C.; Lovett, G.M. [Inst. of Ecosystem Studies, Millbrook, NY (United States)

    2008-05-15

    Beech bark disease (BBD) is having a significant impact on the forest structure and composition of the Catskill Mountains, where forests formerly co-dominated by American beech and sugar maples are now shifting towards sugar maple dominance. In this study, the effects of BBD on annual aboveground net primary production and soil carbon dioxide (CO{sub 2}) efflux were investigated in 8 forest plots in order to examine differences in aboveground net primary productivity (ANPP) and soil CO{sub 2} efflux across a gradient of BBD impacts. A series of plots in a single watershed was used to represent different points along the gradient. The study hypothesized that ANPP would initially increase with BBD impact. The influence of higher nitrogen (N) mineralization rates and greater N availability was also examined. Annual ANPP was estimated as the sum of annual litterfall and annual wood increment. Allometric equations were used to estimate the wood biomass of each tree over a period of 2 years. Soil CO{sub 2} efflux measurements were measured with a temperature probe. Univariate linear and nonlinear regression analyses were used to detect relationships between response variables. Results of the study showed that growing season soil CO{sub 2} efflux declined by 40 per cent along the BBD gradient. 32 refs., 1 tab., 4 figs.

  4. Elastic and Strength Properties of Heat-Treated Beech and Birch Wood

    Directory of Open Access Journals (Sweden)

    Vlastimil Borůvka

    2018-04-01

    Full Text Available This paper deals with the impact of heat treatment on the elastic and strength properties of two diffuse porous hardwoods, namely Fagus sylvatica and Betula pendula. Two degrees of the heat treatment were used at temperatures of 165 °C and 210 °C. The dynamic and static elasticity modulus, bending strength, impact toughness, hardness, and density were tested. It is already known that an increase in treatment temperature decreases the mechanical properties and, on the other hand, leads to a better shape and dimensional stability. Higher temperatures of the heat treatment correlated with lower elastic and strength properties. In the case of higher temperature treatments, the decline of tested properties was noticeable as a result of serious changes in the chemical composition of wood. It was confirmed that at higher temperature stages of treatment, there was a more pronounced decrease in beech properties compared to those of the birch, which was the most evident in their bending strength and hardness. Our research confirmed that there is no reason to consider birch wood to be of a lesser quality, although it is regarded by foresters as an inferior tree species. After the heat treatment, the wood properties are almost the same as in the case of beech wood.

  5. Height-Diameter Models for Mixed-Species Forests Consisting of Spruce, Fir, and Beech

    Directory of Open Access Journals (Sweden)

    Petráš Rudolf

    2014-06-01

    Full Text Available Height-diameter models define the general relationship between the tree height and diameter at each growth stage of the forest stand. This paper presents generalized height-diameter models for mixed-species forest stands consisting of Norway spruce (Picea abies Karst., Silver fir (Abies alba L., and European beech (Fagus sylvatica L. from Slovakia. The models were derived using two growth functions from the exponential family: the two-parameter Michailoff and three-parameter Korf functions. Generalized height-diameter functions must normally be constrained to pass through the mean stand diameter and height, and then the final growth model has only one or two parameters to be estimated. These “free” parameters are then expressed over the quadratic mean diameter, height and stand age and the final mathematical form of the model is obtained. The study material included 50 long-term experimental plots located in the Western Carpathians. The plots were established 40-50 years ago and have been repeatedly measured at 5 to 10-year intervals. The dataset includes 7,950 height measurements of spruce, 21,661 of fir and 5,794 of beech. As many as 9 regression models were derived for each species. Although the “goodness of fit” of all models showed that they were generally well suited for the data, the best results were obtained for silver fir. The coefficient of determination ranged from 0.946 to 0.948, RMSE (m was in the interval 1.94-1.97 and the bias (m was -0.031 to 0.063. Although slightly imprecise parameter estimation was established for spruce, the estimations of the regression parameters obtained for beech were quite less precise. The coefficient of determination for beech was 0.854-0.860, RMSE (m 2.67-2.72, and the bias (m ranged from -0.144 to -0.056. The majority of models using Korf’s formula produced slightly better estimations than Michailoff’s, and it proved immaterial which estimated parameter was fixed and which parameters

  6. Ash recycling to spruce and beech stands effects on nutrients, growth, nitrogen dynamics and carbon balance; Askaaterfoering till gran- och bokbestaand - effekter paa naering, tillvaext, kvaevedynamik och kolbalans

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, Gunnar

    2006-03-15

    Ash recycling is an important part in a modern, sustainable forestry, especially in whole-tree harvest systems. Nutrients lost at harvest are returned to the forest with the wood-ash. In the project the effects of ash treatment on needle and leaf chemistry, tree growth, soil chemistry, soil water chemistry, and carbon and nitrogen dynamics were studied on 23 Norway spruce sites in south-western Sweden and in ten European beech sites in Scania, southern Sweden. On some of the sites there were previously established ash recycling experiments, but on a majority of the sites ash recycling was performed without experimental lay-out and ash and control plots were established afterwards. The most common dose was two tons of self hardened crushed wood-ash and two tons of Mg-lime. On average seven to eight years after ash recycling the results were 1. increased exchangeable stores of base cations in the soil in the beech and the spruce stands 2. increased base saturation in the beech and the spruce stands and increased BC/Al in the spruce stands 3. increased concentrations and ratios to N of P, Ca, Zn, and S in the needles, the increased P-values are especially important since P is close to or below deficiency levels in a majority of the spruce stands 4. decreased K-concentration in the beech leaves 5. increased tree growth with on average 14 % in the ash treated spruce stands compared to the control plots 6. increased carbon and nitrogen amounts in the biomass in the spruce stands 7. tendencies towards increased amounts of carbon and nitrogen in the soil in the beech stands and no effect in the soil in the spruce stands 8. increased concentrations of Ca, Mg, and SO{sub 4} and no effect on ANC in the soil water 9. no effect on potential net mineralization but increased potential nitrification rates 10. decreased concentration of nitrate in the soil water in the beech stands and no effect in the spruce stands 11. lower system N losses in the beech stands and possibly in the

  7. Diversity and primary productivity of hill beech forests from Doftana Valley (Romanian Subcarpathians

    Directory of Open Access Journals (Sweden)

    Mihaela Paucã-Comãnescu

    2009-12-01

    Full Text Available The hill beech forests cover most of the woody area in the Doftana Valley. The present study refers, for the first time, to two beech forests typical to this belt, which belong to the phytocoenological associations Epipactieto-Fagetum (Resmeriţă, 1972, in the Lunca Mare area, and Hieracio rotundati-Fagetum (Vida 1983, Täuber 1987 in the Sotrile area, from floristic, structural, biomass and necromass accumulation point of view, within the framework of the vertical structure of biocoenosis. The limestone substratum, occasionally with small outcrops in the first beech forest, differs chiefly through the pH levels (6.34-5.67 from the siliceous substratum (pH 5.11-4.36 in the second beech forest. The layer of trees is dominated by Fagus sylvatica in both forests; this species is associated with Cerasus avium (4.5%, Acer pseudoplatanus (2% and Sorbus torminalis (2% in the first beech forest, and is monodominant in the second. Although the forest underwent selective cuts, more intense in the Lunca Mare area, the aboveground ligneous biomass reaches nowadays 222 t/ha in the Lunca Mare area compared to only 163 t/ha in the Sotrile area; the average height is 28.8ą2.49 m and 23.7ą1.12 m, respectively, and the diameter is 33.30ą7.9 cm and 31.60ą6.28 cm, respectively. The species of macrofungi, not very numerous during the study because of scarce precipitations (6 and 7 species, respectively, are predominant on the rhytidoma trees in the beech forest rooted on the limestone ground; in the Sotrile beech forest they are joined by mycorrhizal and parasite species. The layer of shrub is underdeveloped. The herbaceous layer is discontinuous, and includes, along herbs, small plants and saplings belonging to the ligneous species and to liana Hedera helix. The maximal value of the aboveground biomass of the layer is 317 kg/ha DM in the Lunca Mare area and 235 kg /ha DM in the Sotrile area. Bryophyta is present in large quantities, especially in the Sotrile

  8. Variations of Mercury Concentrations in American Beech Foliage over a Growing Season

    Science.gov (United States)

    Stinson, I.; Tsui, M. T. K.; Chow, A. T.

    2017-12-01

    Accumulation of atmospheric gaseous mercury (Hg) in foliage is well known, however, a small fraction of Hg always exists as highly bioavailable methylmercury (MeHg) in foliage but the source of MeHg in foliage is unknown. Recent studies suggested in-vivo Hg methylation in foliage while others suggested external inputs (e.g., precipitation) as sources of MeHg in foliage. This study assesses the accumulation of total Hg and MeHg within the foliage of a small sample set of American Beech trees, one of the common tree species in the east coast and the study site is located within the campus of University of North Carolina - Greensboro, over the growing season in 2017 (spring, summer, and fall). In addition, this study evaluates the Hg concentrations in foliage as related to other physiological parameters (e.g., stomatal density, leaf area, chlorophyll, and carbon/nitrogen content) and the changes in environmental characteristics (e.g., sunlight) over the growing season. For this investigation, five American Beech trees with varying characteristics (height, age, and location) were selected. On a biweekly basis, starting late April 2017, foliage samples were collected and composited from different positions on each tree. For the samples processed to date, our results indicate that total Hg accumulation is occurring for all five trees with an initial mean value of 5.79 ng/g, increasing to a mean value of 13.9 ng/g over a ten-week period. Coincidentally, there has been a similar increase in chlorophyll (a+b) concentrations for the foliage, and there is a strong, positive relationship between chlorophyll and total-Hg concentrations. However, we found no relationships between total Hg concentrations and stomatal density of foliage or carbon/nitrogen content. This study is still ongoing and will continue through the end of the growing season in 2017. Additionally, from the same sample sets, besides total Hg analysis and other ancillary parameters in foliage, MeHg analysis

  9. Effect of species composition on carbon and nitrogen stocks in forest floor and mineral soil in Norway spruce and European beech mixed forests

    Science.gov (United States)

    Andivia, Enrique; Rolo, Víctor; Jonard, Mathieu; Formánek, Pavel; Ponette, Quentin

    2015-04-01

    Management of existing forests has been identified as the main strategy to enhance carbon sequestration and to mitigate the impact of climate change on forest ecosystems. In this direction, the conversion of Norway spruce monospecific stands into mixed stands by intermingling individuals of European beech is an ongoing trend in adaptive forest management strategies, especially in Central Europe. However, studies assessing the effect of changes in tree species composition on soil organic carbon (SOC) and nitrogen stocks are still scarce and there is a lack of scientific evidence supporting tree species selection as a feasible management option to mitigate the effects of predicted future climatic scenarios. We compared C and N stocks in the forest floor (litter and humus) and the top 10 cm of mineral soil in two monospecific stands of Norway spruce and European beech and in a mixed stand of both species. The effect of tree species composition on the C and N stocks and its spatial distribution was evaluated based on litterfall, root production, elevation and canopy opening, and by using a combination of modelling and geostatistical techniques. C stock was highest in the Norway spruce and the mixed stands, while N stock was highest in the mixed stand and lowest under European beech, with intermediate values in the Norway spruce stand. Each forest type showed differences in forest floor properties, suggesting that species composition is an important factor governing forest floor characteristics, including C and N stocks. The distribution of C and N stocks between forest soil layers was different for each forest type. C and N stocks were highest in the hummus layer under Norway spruce, whereas both stocks were lowest in the European beech stand. On the other hand, the mixed stand showed the highest C and N accumulation in the uppermost mineral soil layer, while the monospecific stands showed similar values. Litterfall was the main contribution to C and N stocks of the

  10. Beech bark necrosis: partition- ing the environmental and spatial variation of the damage severity in Central and South-Eastern Europe

    Directory of Open Access Journals (Sweden)

    Benjamín Jarčuška

    2013-12-01

    Full Text Available The beech bark necrosis (BBN infestation severity of European beech (Fagus sylvatica L. was assessed in regions of Central (CE and South-Eastern Europe (SE. Altogether more than 10,000 trees were sampled at 114 sites. Using variation partitioning method, we examined the pure and shared effects of stand, site, climate and spatial sets of variables on mean BBN severity. Our rating included (i the whole stand, (ii tree social status classes, (iii canopy (C and (iv understory (U trees separately. We found that C trees were less affected by BBN than sub-canopy and U trees in both regions. There were found inter-regional differences in amount of explained variability (25.4–73.9% for whole stand BBN and in the sensitivity of C and U trees to the environmental gradients. The analysis revealed that the climate and spatial variables followed by stand variables had the largest marginal effects on mean BBN severity in all models, while the site set of variables had the weakest one. More than half of the explained variation was shared among four sets of variables in SE, contrary to CE. Except to U trees in SE, the effect of climate – pure or spatially structured – remained the highest also after partitioning of variance; more in SE than in CE. Taking into account positive association between mean annual temperature and mean BBN severity in C trees in SE, reinforced negative effect of climate change on the necrosis might be expected to be more serious mainly in low situated beech forests there. Promoting the tree species diversity in forested areas with higher incidence of beech bark necrosis, i.e. in low altitudes in SE, could reduce the susceptibility of forests to the necrosis at regional level in the future. For better understanding of the relative importance of environmental and spatial variables on BBN severity, further research performed on finer spatial scale (extent and grain is necessary, along with accounting for pathogens involved in the

  11. Declining atmospheric deposition of heavy metals over the last three decades is reflected in soil and foliage of 97 beech (Fagus sylvatica) stands in the Vienna Woods.

    Science.gov (United States)

    Türtscher, Selina; Berger, Pétra; Lindebner, Leopold; Berger, Torsten W

    2017-11-01

    Rigorous studies on long-term changes of heavy metal distribution in forest soils since the implementation of emission controls are rare. Hence, we resampled 97 old-growth beech stands in the Vienna Woods. This study exploits an extensive data set of soil (infiltration zone of stemflow and between trees area) and foliar chemistry from three decades ago. It was hypothesized that declining deposition of heavy metals is reflected in soil and foliar total contents of Pb, Cu, Zn, Ni, Mn and Fe. Mean soil contents of Pb in the stemflow area declined at the highest rate from 223 to 50 mg kg -1 within the last three decades. Soil contents of Pb and Ni decreased significantly both in the stemflow area and the between trees area down to 80-90 cm soil depth from 1984 to 2012. Top soil (0-5 cm) accumulation and simultaneous loss in the lower soil over time for the plant micro nutrients Cu and Zn are suggested to be caused by plant uptake from deep horizons. Reduced soil leaching, due to a mean soil pH (H 2 O) increase from 4.3 to 4.9, and increased plant cycling are put forward to explain the significant increase of total Mn contents in the infiltration zone of beech stemflow. Top soil Pb contents in the stemflow area presently exceed the critical value at which toxicity symptoms may occur at numerous sites. Mean foliar contents of all six studied heavy metals decreased within the last three decades, but plant supply with the micro nutrients Cu, Zn, Mn and Fe is still in the optimum range for beech trees. It is concluded that heavy metal pollution is not critical for the studied beech stands any longer. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Perry Beeches Coaching Programme: Evaluation Report and Executive Summary

    Science.gov (United States)

    Lord, Pippa; Bradshaw, Sally; Stevens, Eleanor; Styles, Ben

    2015-01-01

    The Perry Beeches Coaching Programme aimed to improve the reading and writing skills of Year 7 pupils with low levels of attainment in four English secondary schools. Across the project, 16 coaches were employed to provide academic support to pupils who had not reached level 4c in English at the end of Key Stage 2. Originally it had been intended…

  13. Hot callusing for propagation of American beech by grafting

    Science.gov (United States)

    David W. Carey; Mary E. Mason; Paul Bloese; Jennifer L. Koch

    2013-01-01

    To increase grafting success rate, a hot callus grafting system was designed and implemented as part of a multiagency collaborative project to manage beech bark disease (BBD) through the establishment of regional BBD-resistant grafted seed orchards. Five years of data from over 2000 hot callus graft attempts were analyzed using a logistic regression model to determine...

  14. Experimental Study on Dry Torrefaction of Beech Wood

    NARCIS (Netherlands)

    Gucho, Eyerusalem Merin; Shahzad, K.; Bramer, Eduard A.; Akhtar, N.A.; Brem, Gerrit

    2015-01-01

    Torrefaction is a thermochemical pre-treatment process for upgrading the properties of biomass to resemble those of fossil fuels such as coal. Biomass properties of particular interest are chemical composition, physical property and combustion characteristics. In this work, torrefaction of beech

  15. HOW ARE PLANT SPECIES IN CENTRAL EUROPEAN BEECH (FAGUS SYLVATICA L. FORESTS AFFECTED BY TEMPERATURE CHANGES? SHIFT OF POTENTIAL SUITABLE HABITATS UNDER GLOBAL WARMING

    Directory of Open Access Journals (Sweden)

    M. C. Jantsch

    2013-10-01

    Full Text Available This study reveals which temperature range is favoured or avoided by 156 forest plant species and how the distribution of potential suitable habitats of species in beech forests may change in the future. We performed 140 phytosociological relevés along a temperature gradient (4.1 to 9.8 °C in Bavaria, southern Germany, on south exposed slopes. One half of the plots were located on acidic substrate, the other half on base-rich substrate. Generalized linear models (GLM were used to analyse species occurrence along the temperature gradient and to model habitats for species in beech forests under a present (1971-2000 and a future climate (2071-2100 scenario assuming a temperature increase of 1.8 °C. Herb species of beech forests are more adapted to lower temperatures and tree species more to higher temperatures. Current habitats will clearly change under increasing temperatures. We found large habitat losses for Luzula sylvatica (Huds. Gaudin, Maianthemum bifolium (L. F. W. Schmidt, Picea abies (L. H. Karst., Prenanthes purpurea L. and large habitat gains for Carpinus betulus L., Impatiens parviflora DC., Prunus avium (L. L. and Quercus petraea (Matt. Liebl. on both substrates. Forestry will be affected positively as well as negatively with a change in tree cultivation. Losses in biodiversity might be strong for mountainous forests and must also be considered in future conservation plans.

  16. Can decision rules simulate carbon allocation for years with contrasting and extreme weather conditions? A case study for three temperate beech forests

    DEFF Research Database (Denmark)

    Campioli, Matteo; Verbeeck, Hans; Van den Bossche, Joris

    2013-01-01

    allocation scheme taking into account drought-induced changes in allocation dynamics and acclimation of respiration. Model validation was performed against extensive datasets of C fluxes and C pools for a 9 years period (2000-2008) for the site of parameterisation (the beech forest of Hesse, France...... allocation and wood growth at beech stands with contrasting climate and standing stock. However, the allocation model required high quality GPP input and errors (even modest) in GPP resulted in large errors in the growth of the tree organs lowest in the modelled sink hierarchy (woody organs). The ability...... of drought-induced changes in fine root dynamics and of short-term thermal acclimation of maintenance respiration should not be overlooked when simulating the C cycle of forests, particularly for sites likely to experience extreme drought and heat waves. The most relevant model bias was the inaccurate...

  17. Intra-specific variations in expression of stress-related genes in beech progenies are stronger than drought-induced responses.

    Science.gov (United States)

    Carsjens, Caroline; Nguyen Ngoc, Quynh; Guzy, Jonas; Knutzen, Florian; Meier, Ina Christin; Müller, Markus; Finkeldey, Reiner; Leuschner, Christoph; Polle, Andrea

    2014-12-01

    Rapidly decreasing water availability as a consequence of climate change is likely to endanger the range of long-lived tree species. A pressing question is, therefore, whether adaptation to drought exists in important temperate tree species like European beech (Fagus sylvatica L.), a wide-spread, dominant forest tree in Central Europe. Here, five beech stands were selected along a precipitation gradient from moist to dry conditions. Neutral genetic markers revealed strong variation within and little differentiation between the populations. Natural regeneration from these stands was transferred to a common garden and used to investigate the expression of genes for abscisic acid (ABA)-related drought signaling [9-cis-epoxy-dioxygenase (NCED), protein phosphatase 2C (PP2C), early responsive to dehydration (ERD)] and stress protection [ascorbate peroxidase (APX), superoxide dismutase (SOD), aldehyde dehydrogenase (ALDH), glutamine amidotransferase (GAT)] that are involved in drought acclimation. We hypothesized that progenies from dry sites exhibit constitutively higher expression levels of ABA- and stress-related genes and are less drought responsive than progenies from moist sites. Transcript levels and stress responses (leaf area loss, membrane integrity) of well-irrigated and drought-stressed plants were measured during the early, mid- and late growing season. Principal component (PC) analysis ordered the beech progenies according to the mean annual precipitation at tree origin by the transcript levels of SOD, ALDH, GAT and ERD as major loadings along PC1. PC2 separated moist and drought treatments with PP2C levels as important loading. These results suggest that phosphatase-mediated signaling is flexibly acclimated to the current requirements, whereas stress compensatory measures exhibited genotypic variation, apparently underlying climate selection. In contrast to expectation, the drought responses were less pronounced than the progeny-related differences and the

  18. Specific impacts of beech and Norway spruce on the structure and diversity of the rhizosphere and soil microbial communities.

    Science.gov (United States)

    Uroz, S; Oger, P; Tisserand, E; Cébron, A; Turpault, M-P; Buée, M; De Boer, W; Leveau, J H J; Frey-Klett, P

    2016-06-15

    The impacts of plant species on the microbial communities and physico-chemical characteristics of soil are well documented for many herbs, grasses and legumes but much less so for tree species. Here, we investigate by rRNA and ITS amplicon sequencing the diversity of microorganisms from the three domains of life (Archaea, Bacteria and Eukaryota:Fungi) in soil samples taken from the forest experimental site of Breuil-Chenue (France). We discovered significant differences in the abundance, composition and structure of the microbial communities associated with two phylogenetically distant tree species of the same age, deciduous European beech (Fagus sylvatica) and coniferous Norway spruce (Picea abies Karst), planted in the same soil. Our results suggest a significant effect of tree species on soil microbiota though in different ways for each of the three microbial groups. Fungal and archaeal community structures and compositions are mainly determined according to tree species, whereas bacterial communities differ to a great degree between rhizosphere and bulk soils, regardless of the tree species. These results were confirmed by quantitative PCR, which revealed significant enrichment of specific bacterial genera, such as Burkholderia and Collimonas, known for their ability to weather minerals within the tree root vicinity.

  19. Transfer Analysis of Provenance Trials Reveals Macroclimatic Adaptedness of European Beech (Fagus sylvatica L.

    Directory of Open Access Journals (Sweden)

    RASZTOVITS, Ervin

    2009-01-01

    Full Text Available The aim of the study was to analyse provenance tests of beech situated close to theSoutheastern-continental limits of the species, in order to develop a response model of adaptation andplasticity of populations on evolutionary-ecological basis, following sudden climatic changes as aresult of transplanting. Modelling of juvenile height was performed with the help of ecodistancevariables. The concept of transfer analysis and ecodistance is based on the hypothesis that phenotypicresponse to macroclimatic changes depends on the inherited adaptive potential of the population andon the magnitude and direction of experienced environmental change. In common garden experiments,the transfer to the planting site is interpreted as simulation of environmental change. The applicationof ecodistance of transfer for evaluating common garden experiments provides much neededquantitative information about response of tree populations to predicted climatic changes.The analysis of three field experiments of European beech in SE Europe invalidate earlier doubtsabout the existence of macroclimatic adaptation patterns in juvenile growth and justify restrictions ofuse of reproductive material on the basis of evolutionary ecology. The presented model illustrates thatresponse to climatic change is regionally divergent, depending on testing conditions and on hereditarytraits. In particular, climatic warming in the central-northern part of the range may lead to productionincrease. However, under the stressful and uncertain conditions at the lower (xeric limit of thespecies, growth depression and vitality loss are predicted. The deviating behaviour of higher elevationprovenances support their separate treatment.The results may be utilised in climate change adaptation and mitigation policy in forestry andnature conservation, to revise rules for use of reproductive material and also for validatingevolutionary and ecological hypotheses related to climate change effects.

  20. Influence of Furfurylation on Practical Properties of Beech Plywood

    Directory of Open Access Journals (Sweden)

    Aisona Talaei

    2016-09-01

    Full Text Available In this study, the influence of Furfurylation on practical properties of beech plywood investigated. Furfurylation of beech layers were performed by impregnation and heat catalyze up to 30% and 70% weight percent gain. Plywood specimens made by 2 resins (Urea Formaldehyde and Methylene Diphenyl Diisocyanate. Practical properties of furfurylated specimens investigated and compared to untreated specimens. Modulus of rupture (MOR, modulus of elasticity (MOE, shear strength, water absorption and thickness swelling were determined. Results revealed that by increasing the furfurylation level, modulus of elasticity (MOE, water absorption and thickness swelling (dimensional stability improved. But modulus of rupture (MOR just increased up to 30% furfurylation and decreased in higher levels of furfurylation. Furfurylation had a negative effect on shear strength of bond line and decreased by increasing the furfurylation level.

  1. China's Beech Forests in the Pre-Quaternary

    Directory of Open Access Journals (Sweden)

    L. Yu-Sheng

    1998-01-01

    Full Text Available Fagus in China is never dominant in Late Cretaceous and Tertiary floras although it might reach its highest diversity in the Miocene. The genus Fagus was more widely distributed during the Palaeogene than in the Neogene. Furthermore, the ecological requirements of Fagus in the Palaeogene seem much broader than those in the Neogene onwards. This is because the Palaeogene floras containing Fagus lived in various conditions from an arid and hot climate to a humid and warm habitat. Additionally, Fagus then coexisted with many kinds of hygrophilous, thermophilous and xerophilous plants. However, the wide distribution, broad ecological adaptation and species composition changed greatly in the Neogene. The Neogene Fagus-containing floras are slightly more similar to the modern beech forests than the Palaeogene ones, although a big difference remains. Chinese fossil data document the post-Tertiary development of the modern beech forests. doi:10.1002/mmng.19980010111

  2. SYNTAXOMOMICAL SURVEY O F EUROPEAN BEECH FORESTS: SOME GENERAL CONCLUSIONS

    Directory of Open Access Journals (Sweden)

    H. DIERSCHKE

    1997-01-01

    Full Text Available A short overwiev is given about the historical development of syntaxonomy of European beech forests. Different solutions of classification have been proposed, following more or less two main approaches: Division of alliances and suballiances by ecologically or geographically orientated species groups. A new classification of European beech forests is proposed with 8 (or more geographically orientated alliances, which can be further divided into suballiances by ecological species groups. For each alliance character and differential species, nomenclatural type and the area is mentioned, based on a (non puplished synthetic table, including 10.006 relevés from all parts of Europe. From this table also some overlapping species groups (a-n are given.

  3. Natural and anthropogenic stress in spruce and beech ecosystems in the Solling project

    International Nuclear Information System (INIS)

    Murach, D.

    1989-01-01

    The investigations show that low Ca/Al-ratios in mineral soil horizons cause a shallow root system with spruce. But obviously other soil conditions expect acidification can also be responsible for a shallow root system. Additional investigations and field experiments have to find out the driving forces. A new phenomenon in fine root investigations are the low fine root concentrations in the uppermost mineral soil horizons. It is to be observed with spruce as well as with beech in stands with strong acidification of the top soil. Further experiments are needed to evaluate what are the main chemical variables (pH, heavy metals etc.) In this way soil acidification can cause reductions of fine root biomasses in subsoils as well as in uppermost soil horizons. These reductions can influence the response of trees to water stress. Relations to the symptoms of needle losses with spruce are likely. The close correlations between the chemistry of the soil, the roots and the needles indicate, that the yellowing symptoms of spruce trees, which were related to Mg-deficiency, are caused by Mg-deficiency in the soil. It is to be emphazised that it is not a pure Mg-deficiency. Ion antagonism to Al and especially to H in connection with fine root distribution are of main importance. (orig.)

  4. THE QUALITY OF THE SURFACE AT THE BEECH WOODTURNING

    Directory of Open Access Journals (Sweden)

    Mirela CHERCIU

    2015-05-01

    Full Text Available There have been experiments made with outside cylindrical beech woodturning with low cutting speed, and feed successively changed. We study, qualitative rather than quantitative, the roughnesss of the surface achieved. It interprets the appearance of each surface based on the theory of cutting considerations. Resulted surface images are given, photographed with a camera and microscope. It appears that here are no propellers generated by the cutting tool nose on the cylindrical part, excepting the situation of using high feeds.

  5. Changes in susceptibility of beech (Fagus sylvatica) seedlings towards Phytophthora citricola under the influence of elevated atmospheric CO{sub 2} and nitrogen fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Fleischmann, F., E-mail: fleischmann@wzw.tum.d [Phytopathology of Woody Plants, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Raidl, S. [Department Biology I and GeoBioCenterLMU, Systematic Mycology, Ludwig Maximilians Universitaet Muenchen, Menzinger Strasse 67, 80638 Muenchen (Germany); Osswald, W.F. [Phytopathology of Woody Plants, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany)

    2010-04-15

    The growth-differentiation balance hypothesis (GDBH) predicts changes in susceptibility of plants against herbivores with changing resource availability. In the presented study we tested the validity of the GDBH for trees infected with a root pathogen. For this purpose Fagus sylvatica seedlings grown under different atmospheric CO{sub 2}- and soil nitrogen regimes were infected with the root pathogen Phytophthora citricola. High nitrogen supply increased total biomass of beech regardless of the CO{sub 2}-treatment, whereas elevated CO{sub 2} enhanced biomass only in the high nitrogen treatment. The responses of beech under the different growing regimes to the Phytophthora root infection were not in line with the predictions of the GDBH. Enhanced susceptibility of beech against P. citricola was found in seedlings grown under elevated CO{sub 2} and low nitrogen supply. Fifteen months after inoculation these plants were characterized by enhanced water use efficiency, by altered root-shoot ratios, and by enhanced specific root tip densities. - Susceptibility of Fagus sylvatica to the root pathogen Phytophthora citricola increased under elevated CO{sub 2}

  6. Changes in susceptibility of beech (Fagus sylvatica) seedlings towards Phytophthora citricola under the influence of elevated atmospheric CO2 and nitrogen fertilization

    International Nuclear Information System (INIS)

    Fleischmann, F.; Raidl, S.; Osswald, W.F.

    2010-01-01

    The growth-differentiation balance hypothesis (GDBH) predicts changes in susceptibility of plants against herbivores with changing resource availability. In the presented study we tested the validity of the GDBH for trees infected with a root pathogen. For this purpose Fagus sylvatica seedlings grown under different atmospheric CO 2 - and soil nitrogen regimes were infected with the root pathogen Phytophthora citricola. High nitrogen supply increased total biomass of beech regardless of the CO 2 -treatment, whereas elevated CO 2 enhanced biomass only in the high nitrogen treatment. The responses of beech under the different growing regimes to the Phytophthora root infection were not in line with the predictions of the GDBH. Enhanced susceptibility of beech against P. citricola was found in seedlings grown under elevated CO 2 and low nitrogen supply. Fifteen months after inoculation these plants were characterized by enhanced water use efficiency, by altered root-shoot ratios, and by enhanced specific root tip densities. - Susceptibility of Fagus sylvatica to the root pathogen Phytophthora citricola increased under elevated CO 2

  7. Phenotypic Plasticity Explains Response Patterns of European Beech (Fagus sylvatica L. Saplings to Nitrogen Fertilization and Drought Events

    Directory of Open Access Journals (Sweden)

    Christoph Dziedek

    2017-03-01

    Full Text Available Abstract: Climate and atmospheric changes affect forest ecosystems worldwide, but little is known about the interactive effects of global change drivers on tree growth. In the present study, we analyzed single and combined effects of nitrogen (N fertilization and drought events (D on the growth of European beech (Fagus sylvatica L. saplings in a greenhouse experiment. We quantified morphological and physiological responses to treatments for one‐ and two‐year‐old plants. N fertilization increased the saplings’ aboveground biomass investments, making them more susceptible to D treatments. This was reflected by the highest tissue dieback in combined N and D treatments and a significant N × D interaction for leaf δ13C signatures. Thus, atmospheric N deposition can strengthen the drought sensitivity of beech saplings. One‐year‐old plants reacted more sensitively to D treatments than two‐year‐old plants (indicated by D‐induced shifts in leaf δ13C signatures of one‐year‐old and two‐year‐old plants by +0.5‰ and −0.2‰, respectively, attributable to their higher shoot:root‐ratios (1.8 and 1.2, respectively. In summary, the saplings’ treatment responses were determined by their phenotypic plasticity (shifts in shoot:root‐ratios, which in turn was a function of both the saplings’ age (effects of allometric growth trajectories = apparent plasticity and environmental impacts (effects of N fertilization = plastic allometry.

  8. Ecological species group—Environmental factors relationships in unharvested beech forests in the north of Iran

    Science.gov (United States)

    Mohammad Naghi Adel; Hassan Pourbabaei; Daniel C. Dey

    2014-01-01

    Beech forests are the richest forest community in Iran because they are both economically and environmentally valuable. The greatest forest volume occurs in Iran's beech forests. Forests dominated by oriental beech (Fagus orientalis Lipskey) cover about 565,000 ha and represent the total area of indigenous forests in Guilan Province. A system...

  9. Litter quality effects of beech and hornbeam on undergrowth species diversity in Luxembourg forests on limestone and decalcified marl

    NARCIS (Netherlands)

    Kooijman, A.M.

    2010-01-01

    Question: Do beech and hornbeam differ in undergrowth species diversity, and could these differences be explained by mass of the organic layer, pH or soil moisture? Could species richness under beech and hornbeam be explained by differences in N dynamics? Location: Ancient forests dominated by beech

  10. The role of granivorous rodents in beech forest regeneration in the Beskydy Mts. (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Heroldová, Marta; Suchomel, J.; Purchart, L.; Homolka, Miloslav

    2008-01-01

    Roč. 1, č. 2 (2008), s. 131-134 ISSN 1803-2451 R&D Projects: GA MZe QH72075 Institutional research plan: CEZ:AV0Z60930519 Keywords : beech mast biomass * granivorous rodents * daily consumption rate * mountain beech forest * regeneration Subject RIV: EH - Ecology, Behaviour

  11. Arthropod diversity in pristine vs. managed beech forests in Transcarpathia (Western Ukraine

    Directory of Open Access Journals (Sweden)

    Vasyl Chumak

    2015-01-01

    We conclude that biodiversity in pristine beech forests is not generally higher than in managed beech forests. However, the much higher amount of dead wood in pristine forests provides a source habitat for saproxylic species spreading into managed forest plots in the same region, but not to distant forests, far from virgin forests, such as in Western Europe.

  12. Wood and bark anatomy of young beech in relation to Cryptococcus attack

    Science.gov (United States)

    David. Lonsdale

    1983-01-01

    Within a sample of European beech, partial resistance to attack by the beech scale, Cryptococcus fagisuga, was associated with a smooth bark which had a regular, vertical pattern in its surface 'growth lines'. Such bark contained relatively little lignified outer parenchyma, and the main stone cell layer was strongly developed. The '...

  13. Timely salvage can reduce losses from beech scale-Nectria attack

    Science.gov (United States)

    David Crosby; J. C. Bjorkbom

    1958-01-01

    Beech is one of our more common hardwoods. It is an important component of the northern hardwood forest type, which occupies about 29 percent of the commercial forest land in the New England and Middle Atlantic States. In terms of total sawtimber volume, beech follows close on sugar maple, red oak, and yellow birch. It is used for a variety of products such as...

  14. Harvested wood products and carbon sink in a young beech high forest

    Directory of Open Access Journals (Sweden)

    Pilli R

    2008-03-01

    Full Text Available According to art. 3.4 of the Kyoto Protocol (KP, Italy has elected forest management as additional human-induced activity to attain the goal of reduction in greenhouse gas emissions. The whole forest area not subjected to afforestation, reforestation or deforestation processes since 1990 will be considered as managed forest. In order to analyse different management strategies, the Carbon-Pro Project, involving 9 partners of the European CADSES area, considered a young beech high forest (ex-coppice, defined as "transitory silvicultural system" as a common case study for the Pre-alps region. Using data collected with forest plans during the period 1983 - 2005, aboveground and belowground forest carbon stock and sink of a specific forest compartment were estimated by the Carbon Stock Method proposed by the IPCC Guidelines. In order to apply this approach 41 trees were cut and a species-specific allometric equation was developed. Considering the aboveground tree biomass, the carbon sink amounts to 1.99 and 1.84 Mg C ha-1 y-1 for the period 1983 - 1994 and 1994 - 2005 respectively. Adding the belowground tree biomass, the estimated sink amounts to 2.59 and 2.39 Mg C ha-1 y-1 for each period. Taking the harvested wood products (firewood, the total carbon sequestration during the second period is 0.16 Mg C ha-1 y-1. The case study highlights the possible rules for the different management strategies. In effect, the utilisation of the entire increase in aboveground biomass as firewood gives an energy substitution effect but, according to the Marrakesh Accords, it cannot be accounted for the KP. On the other hand, an accumulation strategy gives the maximum possible carbon absorption and retention.

  15. Seasonal evolution of carbon allocation to biomass in a French beech forest.

    Science.gov (United States)

    Heid, Laura; Calvaruso, Christophe; Conil, Sébastien; Turpault, Marie-Pierre; Longdoz, Bernard

    2015-04-01

    The objective of this study is to get a better understanding of ecosystem behavior in term of assimilated carbon (C) use. In the global climate change context, this C allocation could play a critical role in predicting ecosystems long terms emissions (Trumbore 2006) and has become a major goal of several emergent studies The monthly C allocation has been determined for a 50-year old beech forest located in north-east of France through the quantification of Gross Primary Production (GPP), biomass production and some of its components (holocelluloses, lignin). In a second phase, the potential factors influencing those productions and allocations throughout a year have been assessed. The temporal evolution of GPP was obtained from the partitioning of eddy-covariance flux measurements and monitored for one year. It was connected to tree aboveground C biomass growth at a monthly step. To achieve the latter, site specific allometric equations were used with trees diameter at breast height (DBH) measured monthly during the growing season on one hand and, on the other hand, C concentrations were deduced from analyses on trunk cores (sampled monthly) and on leaves and bulk branches cores (sampled at the beginning and at the end of the growing season). The C allocated to the aboveground biomass was then estimated, along with the portion allocated to structural C. The results show the delay existing between the end of the tree growth and carbon assimilation. We analyze the possibility to explain this divergence by a compensation coming from the C concentration evolution. Keywords: Carbon allocation, Forest, Biomass production, Carbon concentration, Eddy Covariance Trumbore S. 2006. Carbon Respired by Terrestrial Ecosystems - Recent Progress and Challenges. Global Change Biology 12 (2): 141-53.

  16. Thermal conductivity of high-porosity biocarbon preforms of beech wood

    Science.gov (United States)

    Parfen'eva, L. S.; Orlova, T. S.; Kartenko, N. F.; Sharenkova, N. V.; Smirnov, B. I.; Smirnov, I. A.; Misiorek, H.; Jezowski, A.; Wilkes, T. E.; Faber, K. T.

    2010-06-01

    This paper reports on measurements performed in the temperature range 5-300 K for the thermal conductivity κ and electrical resistivity ρ of high-porosity (cellular pores) biocarbon preforms prepared by pyrolysis (carbonization) of beech wood in an argon flow at carbonization temperatures of 1000 and 2400°C. X-ray structure analysis of the samples has been performed at 300 K. The samples have revealed the presence of nanocrystallites making up the carbon matrices of these biocarbon preforms. Their size has been determined. For samples prepared at T carb = 1000 and 2400°C, the nanocrystallite sizes are found to be in the ranges 12-25 and 28-60 κ( T) are determined for the samples cut along and across the tree growth direction. The thermal conductivity κ increases with increasing carbonization temperature and nanocrystallite size in the carbon matrix of the sample. Thermal conductivity measurements conducted on samples of both types have revealed an unusual temperature dependence of the phonon thermal conductivity for amorphous materials. As the temperature increases from 5 to 300 K, it first increases in proportion to T, to transfer subsequently to ˜ T 1.5 scaling. The results obtained are analyzed.

  17. A slight recovery of soils from Acid Rain over the last three decades is not reflected in the macro nutrition of beech (Fagus sylvatica) at 97 forest stands of the Vienna Woods✰

    Science.gov (United States)

    Berger, Pétra; Lindebner, Leopold

    2016-01-01

    Rigorous studies of recovery from soil acidification are rare. Hence, we resampled 97 old-growth beech stands in the Vienna Woods. This study exploits an extensive data set of soil (infiltration zone of stemflow and between trees area at different soil depths) and foliar chemistry from three decades ago. It was hypothesized that declining acidic deposition is reflected in soil and foliar chemistry. Top soil pH within the stemflow area increased significantly by 0.6 units in both H2O and KCl extracts from 1984 to 2012. Exchangeable Ca and Mg increased markedly in the stemflow area and to a lower extent in the top soil of the between trees area. Trends of declining base cations in the lower top soil were probably caused by mobilization of organic S and associated leaching with high amounts of sulfate. Contents of C, N and S decreased markedly in the stemflow area from 1984 to 2012, suggesting that mineralization rates of organic matter increased due to more favorable soil conditions. It is concluded that the top soil will continue to recover from acidic deposition. However, in the between trees areas and especially in deeper soil horizons recovery may be highly delayed. The beech trees of the Vienna Woods showed no sign of recovery from acidification although S deposition levels decreased. Release of historic S even increased foliar S contents. Base cation levels in the foliage declined but are still adequate for beech trees. Increasing N/nutrient ratios over time were considered not the result of marginally higher N foliar contents in 2012 but of diminishing nutrient uptake due to the decrease in ion concentration in soil solution. The mean foliar N/P ratio already increased to the alarming value of 31. Further nutritional imbalances will predispose trees to vitality loss. PMID:27344089

  18. The yeast flora of some decaying mushrooms on trunks of living trees

    NARCIS (Netherlands)

    Middelhoven, W.J.

    2004-01-01

    Several ascomycetous and basidiomycetous yeasts were isolated from rotten mushrooms on the trunks of beech and tamarisk trees. One strain, identified as the novel species Cryptococcus allantoinivorans, assimilated allantoin as the sole carbon source. Phylogenetically it belongs to the C. laurentii

  19. Nitrogen addition enhances drought sensitivity of young deciduous tree species

    Directory of Open Access Journals (Sweden)

    Christoph Dziedek

    2016-07-01

    Full Text Available Understanding how trees respond to global change drivers is central to predict changes in forest structure and functions. Although there is evidence on the mode of nitrogen (N and drought (D effects on tree growth, our understanding of the interplay of these factors is still limited. Simultaneously, as mixtures are expected to be less sensitive to global change as compared to monocultures, we aimed to investigate the combined effects of N addition and D on the productivity of three tree species (Fagus sylvatica, Quercus petraea, Pseudotsuga menziesii in relation to functional diverse species mixtures using data from a four-year field experiment in Northwest Germany. Here we show that species mixing can mitigate the negative effects of combined N fertilization and D events, but the community response is mainly driven by the combination of certain traits rather than the tree species richness of a community. For beech, we found that negative effects of D on growth rates were amplified by N fertilization (i.e. combined treatment effects were non-additive, while for oak and fir, the simultaneous effects of N and D were additive. Beech and oak were identified as most sensitive to combined N+D effects with a strong size-dependency observed for beech, suggesting that the negative impact of N+D becomes stronger with time as beech grows larger. As a consequence, the net biodiversity effect declined at the community level, which can be mainly assigned to a distinct loss of complementarity in beech-oak mixtures. This pattern, however, was not evident in the other species-mixtures, indicating that neighborhood composition (i.e. trait combination, but not tree species richness mediated the relationship between tree diversity and treatment effects on tree growth. Our findings point to the importance of the qualitative role (‘trait portfolio’ that biodiversity play in determining resistance of diverse tree communities to environmental changes. As such, they

  20. Reciprocal trade of Carbon and Nitrogen at the root-fungus interface in ectomycorrhizal beech plants

    Science.gov (United States)

    Kaiser, Christina; Mayerhofer, Werner; Dietrich, Marlies; Gorka, Stefan; Schintlmeister, Arno; Reipert, Siegfried; Schweiger, Peter; Weidinger, Marieluise; Wiesenbauer, Julia; Martin, Victoria; Richter, Andreas; Woebken, Dagmar

    2017-04-01

    Plants deliver recently assimilated carbon (C) to mycorrhizal fungi, and receive nutrients, such as N and P, in exchange. A reciprocal exchange of C and nutrients between plants and mycorrhizal fungi (i.e., fungi which deliver more nutrients receive more plant C in return and vice versa) has been suggested for arbuscular mycorrhizal symbioses by some studies, but challenged by others. For ectomycorrhizal associations even less is known on how the exchange of C for nutrients is regulated, and whether it is based on reciprocity, or other controls. The aim of this study was to test the concept of reciprocal rewards between beech (Fagus sylvatica) and their associated ectomycorrhizal fungi on different scales, namely (a) across associations between individual root tips of beech and different fungal partners, and (b) at the subcellular scale at the plant-fungus interface. We exposed young beech trees associated with natural mycorrhizal fungal communities to a 13CO2 atmosphere and added 15N-labelled amino acids to a 'litter compartment', that mycorrhizal hyphae, but not plant roots could access. Plants were harvested within 2 days after application of 15N and less than one day after applying 13CO2. If the trading of C for N was reciprocal, we expect that 13C would be correlated to 15N across individual plant-fungal connections and at the subcellular scale within one mycorrhizal root tip, respectively. We collected individual mycorrhizal root-tips from 8 plants right after harvest, analyzed their 13C and 15N content by isotope-ratio mass spectrometry (EA-IRMS) and performed ITS sequencing to identify fungal communities associated with individual root tips. Selected mycorrhizal root tips were also prepared for nano-scale secondary ion mass spectrometry (NanoSIMS) to visualize the spatial distribution of 13C and 15N in cross-sections of mycorrhizal root-tips at the subcellular scale. Our results showed a significant, albeit weak correlation between 13C and 15N across

  1. Similar net ecosystem exchange of beech stands located in France and Denmark

    DEFF Research Database (Denmark)

    Granier, A.; Pilegaard, K.; Jensen, N.O.

    2002-01-01

    Net ecosystem exchange (NEE), as measured with eddy covariance was compared for two European beech stands for the years 1996-1999: a young beech forest (32 year-old) growing in east France, and a mature beech stand (80 year-old) located in Denmark. Those sites are included in the Carboeuroflux...... the growing season. Related to this close parallelism was the similarity of temporal variation in temperature and in global radiation range and variations. Nevertheless, different rainfall distribution within the years, especially in 1997, induced different water stress intensities at the two sites...

  2. Species richness pattern along altitudinal gradient in Central European beech forests

    Czech Academy of Sciences Publication Activity Database

    Hrivnák, R.; Gömöry, D.; Slezák, M.; Ujházy, K.; Hédl, Radim; Jarčuška, B.; Ujházyová, M.

    2014-01-01

    Roč. 49, č. 3 (2014), s. 425-441 ISSN 1211-9520 Institutional support: RVO:67985939 Keywords : altitude * beech-dominated forest * species richness Subject RIV: EF - Botanics Impact factor: 1.778, year: 2014

  3. Investigation of beech wood modified by radio-frequency discharge plasma

    Czech Academy of Sciences Publication Activity Database

    Novák, I.; Popelka, A.; Špitalský, Z.; Mičušík, M.; Omastová, M.; Valentin, M.; Sedliačik, J.; Janigová, I.; Kleinová, A.; Šlouf, Miroslav

    2015-01-01

    Roč. 119, September (2015), s. 88-94 ISSN 0042-207X Institutional support: RVO:61389013 Keywords : radio-frequency plasma * beech wood * adhesive properties Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.558, year: 2015

  4. Chilling and forcing requirements for foliage bud burst of European beech (Fagus sylvatica L.) differ between provenances and are phenotypically plastic

    DEFF Research Database (Denmark)

    Kramer, Koen; Ducousso, Alexis; Gömöry, Dušan

    2017-01-01

    Abstract The timing of foliar budburst is an important component of the fitness of trees. Adaptation of budburst to local temperatures and phenotypic plasticity in the date of budburst to changes in temperature can therefore be expected. In this study, we analysed provenance trials of European...... beech (Fagus sylvatica L.) established over a wide geographic and climatic range in Europe. The analysis was based on a phenological model that represents the key processes at budburst phenology of temperate- and boreal zone deciduous trees. We conclude that adaptive differences exist between...... provenances in the critical chilling- and forcing requirements triggering budburst. Moreover, it is likely that these provenances show a plastic response to local environmental conditions for these two factors. Chilling- and forcing temperature requirements are key traits determining a tree’s response...

  5. Flux-profile relationships over a fetch limited beech forest

    DEFF Research Database (Denmark)

    Dellwik, E.; Jensen, N.O.

    2005-01-01

    heat flux and momentum (phi(h) and phi(m)) and analysed as a function of atmospheric stability and fetch. For heat, the influences of the roughness sublayer and the internal boundary layer were in agreement with previous studies. For momentum, the strong vertical gradient of the flow just above...... surface. The different influence of the roughness sublayer on phi(h) and phi(m) is reflected in the aerodynamic resistance for the site. The aerodynamic resistance for sensible heat is considerably smaller than the corresponding value for momentum.......The influence of an internal boundary layer and a roughness sublayer on flux-profile relationships for momentum and sensible heat have been investigated for a closed beech forest canopy with limited fetch conditions. The influence was quantified by derivation of local scaling functions for sensible...

  6. Joint Slovak-Ukraine-Germany Beech Ecosystems as the World Natural Heritage

    Directory of Open Access Journals (Sweden)

    Vološčuk Ivan

    2014-08-01

    Full Text Available The European beech Fagus sylvatica L. ssp. sylvatica L. is exclusively found in Europe. The beech survived the ice age in small refuges in the south and south-east Europe and went on to colonise large parts of the continent. The post-ice age colonisation of the landscape by the beech took place parallel to the settlement of land by humans and the formation of a more complex society. For centuries much of the Carpathian mountain forests remained untouched (Fig. 1. Virgin forests constitute a natural heritage of global significance. In 2007, 10 protected areas with the Primeval Beech Forests of Carpathians (Slovakia, Ukraine were added to UNESCO’s World Heritage List. On 25 June 2011, the UNESCO World Heritage Committee added five of Germany’s beech forest protected areas to the World Heritage List. This extended the transboundary world natural heritage site ‘Primeval Beech Forest of the Carpathians’, located in the Slovak Republic and Ukraine, to include a German forest protected areas, and renamed it ‘Primeval Beech Forests of the Carpathians and Ancient Beech Forests of Germany’. This paper is aimed at the presentation of the outstanding universal value of the ecological processes in the Joint World Heritage Sites, short description of protected areas and principles of their integrated management plan. This paper also deals with problems in management plan realisation in practice. Ultimate goal is to achieve that management and socio-economic sustainable development practices are in harmony with primary objectives of World Heritage Site protection, biodiversity conservation, ecosystem and landscape stability, rational use of natural resources, ecotourism development and with potential of the landscape in largest possible extend.

  7. Ecological, Typological Properties and Photosynthetic Activity (FAPAR of Common Beech (Fagus sylvatica L. Ecosystems in Croatia

    Directory of Open Access Journals (Sweden)

    Ivan Pilaš

    2016-12-01

    Full Text Available Background and purpose: The purpose of this study was to assess the structural and functional properties of common beech forest ecosystems in Croatia across a wide macro-climatic gradient (Mediterranean, Alpine and Continental and to gain insight into the ways they adapt to progressing short-term climatic extremes and anomalies. Material and Methods: Research was undertaken by integration of the expert based, country scale typological delineation of 13 beech ecosystem types, climatic and topographic grids and indices of ecosystem performances such as the JRC FAPAR (Fraction of Absorbed Photosynthetically Active Radiation. Results: This study reveals preferential environmental conditions for beech ecosystem types together with limiting conditions in three margins of the beech distribution area: highest altitudinal zone, south-eastern continental Pannonian zone and the Mediterranean. The results show that the common beech can adapt to a very wide range of environmental conditions: annual mean temperatures from 2.1oC to 13.5oC, annual precipitation from 739 mm to 3444 mm, and altitudinal range from 20.3 m up to 1576 m above sea level. FAPAR reveals some new insight into the adaptive potential and response mechanisms of the common beech to emerging climate change. Conclusion: The common beech has great potential to adapt to increasing spring warming by a preterm shift of phenology onset and retain relatively stable productivity during the phenology peak in July and August, unrelated to external climatic forcing. These findings indicate that the flexibility of phenological timing, especially during springtime, present one of the important mechanisms of adaptation and resilience of the common beech.

  8. Ecological, Typological Properties and Photosynthetic Activity (FAPAR of Common Beech (Fagus sylvatica L. Ecosystems in Croatia

    Directory of Open Access Journals (Sweden)

    Ivan Pilaš

    2017-01-01

    Full Text Available Background and purpose: The purpose of this study was to assess the structural and functional properties of common beech forest ecosystems in Croatia across a wide macro-climatic gradient (Mediterranean, Alpine and Continental and to gain insight into the ways they adapt to progressing short-term climatic extremes and anomalies. Material and Methods: Research was undertaken by integration of the expert based, country scale typological delineation of 13 beech ecosystem types, climatic and topographic grids and indices of ecosystem performances such as the JRC FAPAR (Fraction of Absorbed Photosynthetically Active Radiation. Results: This study reveals preferential environmental conditions for beech ecosystem types together with limiting conditions in three margins of the beech distribution area: highest altitudinal zone, south-eastern continental Pannonian zone and the Mediterranean. The results show that the common beech can adapt to a very wide range of environmental conditions: annual mean temperatures from 2.1oC to 13.5oC, annual precipitation from 739 mm to 3444 mm, and altitudinal range from 20.3 m up to 1576 m above sea level. FAPAR reveals some new insight into the adaptive potential and response mechanisms of the common beech to emerging climate change. Conclusion: The common beech has great potential to adapt to increasing spring warming by a preterm shift of phenology onset and retain relatively stable productivity during the phenology peak in July and August, unrelated to external climatic forcing. These findings indicate that the flexibility of phenological timing, especially during springtime, present one of the important mechanisms of adaptation and resilience of the common beech.

  9. Carbon and Nitrogen Pools and Fluxes in Adjacent Mature Norway Spruce and European Beech Forests

    Directory of Open Access Journals (Sweden)

    Filip Oulehle

    2016-11-01

    Full Text Available We compared two adjacent mature forest ecosystem types (spruce vs. beech to unravel the fate of assimilated carbon (C and the cycling of organic and inorganic nitrogen (N without the risk of the confounding influences of climatic and site differences when comparing different sites. The stock of C in biomass was higher (258 t·ha−1 in the older (150 years beech stand compared to the younger (80 years planted spruce stand (192 t·ha−1, whereas N biomass pools were comparable (1450 kg·ha−1. Significantly higher C and N soil pools were measured in the beech stand, both in forest floor and mineral soil. Cumulative annual CO2 soil efflux was similar among stands, i.e., 9.87 t·ha−1·year−1 of C in the spruce stand and 9.01 t·ha−1·year−1 in the beech stand. Soil temperature explained 78% (Q10 = 3.7 and 72% (Q10 = 4.2 of variability in CO2 soil efflux in the spruce and beech stand, respectively. However, the rather tight N cycle in the spruce stand prevented inorganic N losses, whereas losses were higher in the beech stand and were dominated by nitrate in the mineral soil. Our results highlighted the long-term consequences of forest management on C and N cycling.

  10. Genetic effects of air pollution on forest tree species of the Carpathian Mountains

    International Nuclear Information System (INIS)

    Longauer, Roman; Goemoery, Dusan; Paule, Ladislav; Blada, Ioan; Popescu, Flaviu; Mankovska, Blanka; Mueller-Starck, Gerhard; Schubert, Roland; Percy, Kevin; Szaro, Robert C.; Karnosky, David F.

    2004-01-01

    The effects of air pollution on the genetic structure of Norway spruce, European silver fir and European beech were studied at four polluted sites in Slovakia, Romania and Czech Republic. In order to reduce potential effects of site heterogeneity on the health condition, pair-wise sampling of pollution-tolerant and sensitive trees was applied. Genotypes of sampled trees were determined at 21 isozyme gene loci of spruce, 18 loci of fir and 15 loci of beech. In comparison with Norway spruce, fewer genetic differences were revealed in beech and almost no differentiation between pollution-tolerant and sensitive trees was observed in fir. In adult stands of Norway spruce, sensitive trees exhibited higher genetic multiplicity and diversity. The decline of pollution-sensitive trees may result thus in a gradual genetic depletion of pollution-exposed populations of Norway spruce through the loss of less frequent alleles with potential adaptive significance to altered stressing regimes in the future. Comparison of the subsets of sensitive and tolerant Norway spruce individuals as determined by presence or absence of discolorations (''spruce yellowing'') revealed different heterozygosity at 3 out of 11 polymorphic loci. - Genetic effects of air pollution on main forest trees of the Carpathians are species- and site-specific

  11. Risk of genetic maladaptation due to climate change in three major European tree species.

    Science.gov (United States)

    Frank, Aline; Howe, Glenn T; Sperisen, Christoph; Brang, Peter; Clair, J Bradley St; Schmatz, Dirk R; Heiri, Caroline

    2017-12-01

    Tree populations usually show adaptations to their local environments as a result of natural selection. As climates change, populations can become locally maladapted and decline in fitness. Evaluating the expected degree of genetic maladaptation due to climate change will allow forest managers to assess forest vulnerability, and develop strategies to preserve forest health and productivity. We studied potential genetic maladaptation to future climates in three major European tree species, Norway spruce (Picea abies), silver fir (Abies alba), and European beech (Fagus sylvatica). A common garden experiment was conducted to evaluate the quantitative genetic variation in growth and phenology of seedlings from 77 to 92 native populations of each species from across Switzerland. We used multivariate genecological models to associate population variation with past seed source climates, and to estimate relative risk of maladaptation to current and future climates based on key phenotypic traits and three regional climate projections within the A1B scenario. Current risks from climate change were similar to average risks from current seed transfer practices. For all three climate models, future risks increased in spruce and beech until the end of the century, but remained low in fir. Largest average risks associated with climate projections for the period 2061-2090 were found for spruce seedling height (0.64), and for beech bud break and leaf senescence (0.52 and 0.46). Future risks for spruce were high across Switzerland. However, areas of high risk were also found in drought-prone regions for beech and in the southern Alps for fir. Genetic maladaptation to future climates is likely to become a problem for spruce and beech by the end of this century, but probably not for fir. Consequently, forest management strategies should be adjusted in the study area for spruce and beech to maintain productive and healthy forests in the future. © 2017 John Wiley & Sons Ltd.

  12. Temperature responses of growth and wood anatomy in European beech saplings grown in different carbon dioxide concentrations

    International Nuclear Information System (INIS)

    Overdieck, D.; Ziche, D.; Bottcher-Jungclaus, K.

    2007-01-01

    This study investigated relationships between wood anatomical properties, growth, and mass allocation of well-watered beech saplings growing in different temperature and carbon dioxide (CO 2 ) regimes. The study was conducted to test whether growth was enhanced by increasing temperature and CO 2 , as well as to determine whether the leaf area to stem cross-sectional area ratio, leaf mass ratio, and leaf area ratio declined with increasing temperature. The study also investigated the hypothesis that vessel member and size decreases with increasing temperature and CO 2 as well as the hypothesis that wood parenchyma content declines with increasing temperature and increases in response to elevated CO 2 . The beech saplings were grown in 7-1 pots for 2.5 years in field-phytotron chambers supplied with ambient or elevated CO 2 . Temperatures in the chambers ranged in increments of 2 degrees C. Soil was not fertilized and soil water and air humidity were kept constant. Data were evaluated by regression analysis. Results of the study showed that stem diameter was significantly larger at increased temperatures. In addition, stems were taller, and leaf area and stem mass were greater. The allocation pattern was influenced by temperature, as leaf mass ratio and leaf area ratio decreased with increasing temperature. Elevated CO 2 enhanced height growth by 8.8 per cent, and decreased coarse root mass and total mass by 10.3 per cent. The root/shoot ratio was decreased by 11.7 per cent. At final harvest, a synergistic interaction was observed between elevated CO 2 and temperature yielded trees that were 3.2 per cent taller at -4 degrees C, and 12.7 per cent taller at 4 degrees C than trees grown in ambient CO 2 . After 2.5 seasons, the cross-sectional area of the oldest stem part was approximately 32 per cent greater in the 4 degree C treatment than the -4 degree C treatment. In the final year, approximately 67 per cent more leaf area per unit tree ring area was produced in the

  13. Effects of drought on leaf carbon source and growth of European beech are modulated by soil type

    Science.gov (United States)

    Liu, Jian-Feng; Arend, Matthias; Yang, Wen-Juan; Schaub, Marcus; Ni, Yan-Yan; Gessler, Arthur; Jiang, Ze-Ping; Rigling, Andreas; Li, Mai-He

    2017-02-01

    Drought potentially affects carbon balance and growth of trees, but little is known to what extent soil plays a role in the trade-off between carbon gain and growth investment. In the present study, we analyzed leaf non-structural carbohydrates (NSC) as an indicator of the balance of photosynthetic carbon gain and carbon use, as well as growth of European beech (Fagus sylvatica L.) saplings, which were grown on two different soil types (calcareous and acidic) in model ecosystems and subjected to a severe summer drought. Our results showed that drought led in general to increased total NSC concentrations and to decreased growth rate, and drought reduced shoot and stem growth of plants in acidic soil rather than in calcareous soil. This result indicated that soil type modulated the carbon trade-off between net leaf carbon gain and carbon investment to growth. In drought-stressed trees, leaf starch concentration and growth correlated negatively whereas soluble sugar:starch ratio and growth correlated positively, which may contribute to a better understanding of growth regulation under drought conditions. Our results emphasize the role of soil in determining the trade-off between the balance of carbon gain and carbon use on the leaf level and growth under stress (e.g. drought).

  14. Non-linear height-diameter models for oriental beech (Fagus orientalis Lipsky in the Hyrcanian forests, Iran

    Directory of Open Access Journals (Sweden)

    Ahmadi, K.

    2013-01-01

    Full Text Available The relationship between tree height and diameter is an important element in growth and yield models, in carbon budget and timber volume models, and in the description of stand dynamics. Six non-linear growth functions (i.e. Chapman-Richards, Schnute, Lundqvist/Korf, Weibull, Modified Logistic and Exponential were fitted to tree height-diameter data of oriental beech in the Hyrcanian mixed hardwood forests of Iran. The predictive performance of these models was in the first place assessed by means of different model evaluation criteria such as adjusted R squared (adjR2, root mean square error (RMSE, Akaike information criterion (AIC, mean difference (MD, mean absolute difference (MAD and mean square (MS error criteria. Although each of the six models accounted for approximately 75% of total variation in height, a large difference in asymptotic estimates was observed. Apart from this, the predictive performance of the models was also evaluated by means of cross-validation and by splitting the data into 5-cm diameter classes. Plotting the MD in relation to these diameter at breast height (DBH classes showed for all growth functions, except for the Modified Logistic function, similar mean prediction errors for small- and medium-sized trees. Large-sized trees, however, showed a higher mean prediction error. The Modified Logistic function showed the worst performance due to a large model bias. The Exponential and Lundqvist/Korf models were discarded due to their showing biologically illogical behavior and unreasonable estimates for the asymptotic coefficient, respectively. Considering all the above-mentioned criteria, the Chapman-Richards, Weibull, and Schnute functions provided the most satisfactory height predictions. However, we would recommend the Chapman-Richards function for further analysis because of its higher predictive performance.

  15. Meteorological Drivers of Extremes in Daily Stem Radius Variations of Beech, Oak and Pine in Northeastern Germany: An Event Coincidence Analysis

    Directory of Open Access Journals (Sweden)

    Jonatan Frederik Siegmund

    2016-06-01

    Full Text Available Observed recent and expected future increases in frequency and intensity of climatic extremes in central Europe may pose critical challenges for domestic tree species. Continuous dendrometer recordings provide a valuable source of information on tree stem diameter or radius variations, offering the possibility to study a tree's response to environmental influences at a high temporal resolution. In this study, we analyze stem radius variations (SRV of three domestic tree species (beech, oak and pine from 2012 to 2014. We use the novel statistical approach of event coincidence analysis (ECA to investigate the simultaneous occurrence of extreme daily weather conditions and extreme SRVs, where extremes are defined with respect to the common values at a given phase of the annual growth period. Besides defining extreme events based on individual meteorological variables, we additionally introduce conditional and joint ECA as new multivariate extensions of the original methodology and apply them for testing 105 different combinations of variables regarding their impact on SRV extremes. Our results reveal a strong susceptibility of all three species to the extremes of several meteorological variables. Yet, the inter-species differences regarding their response to the meteorological extremes are comparatively low. The obtained results provide a thorough extension of previous correlation-based studies by emphasizing on the timings of climatic extremes only. We suggest that the employed methodological approach should be further promoted in forest research regarding the investigation of tree responses to changing environmental conditions.

  16. Mechanical properties of Beech -Furfuryl alcohol wood polymer

    Directory of Open Access Journals (Sweden)

    Hamideh Abdolzadeh

    2013-11-01

    Full Text Available In this study, mechanical properties of wood polymer (beech-furfuryl alcohol were investigated. In this regard, the properties of specimens with three different values of furfurylation (20%, 30% and 65% in comparison with control specimens were evaluated. The furfurylation was carried out with impregnation of specimens with full-cell method followed by polymerization of furfuryl alcohol monomer with heat catalyst. Static bending, tension perpendicular to the grain, compression parallel and perpendicular to the grain, shear parallel to the grain and hardness of specimens were determined according to ASTM D-143. Results have shown that with increasing furfurylation, static bending strength increases and tension perpendicular to the grain decreases. In addition, the compression perpendicular to the grain and shear parallel to the grain in specimens with high furfurylation value increases in comparison with control specimens. The radial hardness of the wood polymer sp­ecimens in comparison with control specimens increases greatly and ascendant trend of specimen's hardness was observed being increasing with furfurylation value.

  17. Response of the leaf phenology and tree-ring width of European beech to climate variability

    Czech Academy of Sciences Publication Activity Database

    Kolář, Tomáš; Giagli, K.; Trnka, Miroslav; Bednářová, E.; Vavrčík, H.; Rybníček, Michal

    2016-01-01

    Roč. 50, č. 2 (2016), č. článku 1520. ISSN 0037-5330 R&D Projects: GA MŠk(CZ) LO1415; GA ČR GA13-04291S Grant - others:EHP(CZ) EHP-CZ02-OV-1-014-2014 Program:CZ02 Institutional support: RVO:67179843 Keywords : dendroclimatology * Fagus sylvatica * temperature * radial increment * soil moisture Subject RIV: EH - Ecology, Behaviour Impact factor: 1.495, year: 2016

  18. Listening to old beech and young cherry trees - long-term research in the Alleghenies

    Science.gov (United States)

    Susan L. Stout; Coeli M. Hoover; Todd E. Ristau

    2006-01-01

    Long-term research results have been a foundation of forestry practice on the Allegheny Plateau since the 1970s. This includes results from monitoring reference conditions in areas set aside for this purpose and from long-running manipulative studies, some dating back to the 1920s. The success of long-term research in this region reflects the commitment of a handful of...

  19. Large beech (Fagus sylvatica) trees as ‘lifeboats’ for lichen diversity in central European forests

    Czech Academy of Sciences Publication Activity Database

    Hofmeister, J.; Hošek, J.; Malíček, J.; Palice, Zdeněk; Syrovátková, L.; Steinová, J.; Černajová, I.

    2016-01-01

    Roč. 25, č. 6 (2016), s. 1073-1090 ISSN 0960-3115 Institutional support: RVO:67985939 Keywords : Fagus * forest management * Red-listed species Subject RIV: EH - Ecology, Behaviour Impact factor: 2.265, year: 2016

  20. Cryptogamic stem covers may contribute to nitrous oxide consumption by mature beech trees

    Czech Academy of Sciences Publication Activity Database

    Macháčová, Kateřina; Maier, M.; Svobodová, Kateřina; Lang, F.; Urban, Otmar

    2017-01-01

    Roč. 7, OCT (2017), č. článku 13243. ISSN 2045-2322 R&D Projects: GA MŠk(CZ) LO1415; GA MŠk(CZ) LM2015061; GA ČR(CZ) GJ17-18112Y Institutional support: RVO:67179843 Keywords : nitrous oxide * N2O * field conditions * cryptogamic stem Subject RIV: ED - Physiology OBOR OECD: Plant sciences, botany Impact factor: 4.259, year: 2016

  1. The natural abundance of 15N in litter and soil profiles under six temperate tree species: N cycling depends on tree species traits and site fertility

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Nilsson, Lars Ola; Schmidt, Inger Kappel

    2013-01-01

    for these N variables and for the litter δ15N and enrichment factor. Litter from ash and sycamore maple with high N status and low fungal mycelia activity was enriched in 15N (+0.9 delta units) relative to other tree species (European beech, pedunculate oak, lime and Norway spruce) even though the latter...... species leached more nitrate.The δ15N pattern reflected tree species related traits affecting the N cycling as well as site fertility and former land use, and possibly differences in N leaching. The tree species δ15N patterns reflected fractionation caused by uptake of N through mycorrhiza rather than due...

  2. Preliminary report of ecological factors influencing incidence and severity of beech bark disease in the Appalachian region

    Science.gov (United States)

    David P. McCann; William L. MacDonald

    2013-01-01

    Resistance to Cryptococcus fagisuga, a primary component of the beech bark disease (BBD) complex, is heritable. Reportedly about 1-2 percent of American beech (Fagus grandifolia Ehrh.) are genetically resistant to C. fagisuga. This project is designed to identify environmental factors contributing to BBD...

  3. Ungulate Impact on Natural Regeneration in Spruce-Beech-Fir Stands in Černý důl Nature Reserve in the Orlické Hory Mountains, Case Study from Central Sudetes

    Directory of Open Access Journals (Sweden)

    Zdeněk Vacek

    2014-11-01

    Full Text Available The paper presents the results of a study on tree regeneration of forest stands in the Černý důl Nature Reserve, which is situated in the Orlické hory Mountains Protected Landscape area in the Czech Republic. Research was conducted in a spruce-beech stand with an admixture of silver fir, sycamore maple and rowan on two comparative permanent research plots (PRPs (PRP 1—fenced enclosure and PRP 2—unfenced. Typological, soil, phytosociological and stand characteristics of the two PRPs are similar. The results showed that ungulate browsing is a limiting factor for successful development of natural regeneration of autochthonous tree species. The population of tree species of natural regeneration on the fenced plot (PRP 1 is sufficient in relation to the site and stand conditions. However, natural regeneration on PRP 2 is considerably limited by browsing. Damage is greatest to fir, sycamore maple and rowan; less severe to beech; and the least to spruce.

  4. Leaf morphology and phenology of Beech (Fagus sylvatica L.) are linked to environmental conditions depending on the altitudinal origin

    Science.gov (United States)

    Capdevielle-Vargas, Renee; Schuster, Christina; Estrella, Nicole; Menzel, Annette

    2014-05-01

    One of the principal responses of temperate climate trees to climate warming, besides migration, will be in-situ adaptation/evolution. For both, germination and growth rates can have a strong impact on survival and long-term recruitment and establishment of a species. Leaf morphology traits, together with phenology, are relevant to the study of inherent capacities of plants to adapt to an ever changing climate, especially in alpine regions, where a rapid warming has been observed in the last decades. The aim of this study was to evaluate the changes in possible adaptive traits (e.g. leaf morphology and phenology) of Beech (Fagus sylvatica L.) and to asses a decisive component of the survival strategy of this important broadly distributed Central European tree species. We collected beech seeds at six sites along two transects of a south- (900, 1000 and 1100-1400 m.a.s.l.) and a north-facing slope (800, 900 and 1100 m.a.s.l.) in 2011 (mast year) near Garmisch-Partenkirchen, Germany. All the seeds were stratified before sowing; 150 seeds were selected from each site and sowed (at the beginning of the spring) in square containers in a greenhouse under the same climatic conditions; seven phenological stages were defined following a modified beech germination key and the phenology of every seed was recorded three times a week. Harvesting took place 38/42 days after sowing and the specific leaf area (SLA), biomass, and leaf morphology (lamina length and width) were recorded for each seedling. Seeds from lower sites of the two transects presented a poorer germination rates (e.g. 30% for the south 900 m.a.s.l. site) and (75% for the north 800 m.a.s.l. site) when compared to seeds originating from higher elevations within the same transect. The highest germination percentages (98 and 85%) were observed in seeds originating from the highest elevations (e.g. 1100-1400 m.a.s.l. of the south site and 1100 m.a.s.l. of the north site, respectively). Although no significant

  5. Up in the tree--the overlooked richness of bryophytes and lichens in tree crowns.

    Directory of Open Access Journals (Sweden)

    Steffen Boch

    Full Text Available Assessing diversity is among the major tasks in ecology and conservation science. In ecological and conservation studies, epiphytic cryptogams are usually sampled up to accessible heights in forests. Thus, their diversity, especially of canopy specialists, likely is underestimated. If the proportion of those species differs among forest types, plot-based diversity assessments are biased and may result in misleading conservation recommendations. We sampled bryophytes and lichens in 30 forest plots of 20 m × 20 m in three German regions, considering all substrates, and including epiphytic litter fall. First, the sampling of epiphytic species was restricted to the lower 2 m of trees and shrubs. Then, on one representative tree per plot, we additionally recorded epiphytic species in the crown, using tree climbing techniques. Per tree, on average 54% of lichen and 20% of bryophyte species were overlooked if the crown was not been included. After sampling all substrates per plot, including the bark of all shrubs and trees, still 38% of the lichen and 4% of the bryophyte species were overlooked if the tree crown of the sampled tree was not included. The number of overlooked lichen species varied strongly among regions. Furthermore, the number of overlooked bryophyte and lichen species per plot was higher in European beech than in coniferous stands and increased with increasing diameter at breast height of the sampled tree. Thus, our results indicate a bias of comparative studies which might have led to misleading conservation recommendations of plot-based diversity assessments.

  6. Up in the Tree – The Overlooked Richness of Bryophytes and Lichens in Tree Crowns

    Science.gov (United States)

    Boch, Steffen; Müller, Jörg; Prati, Daniel; Blaser, Stefan; Fischer, Markus

    2013-01-01

    Assessing diversity is among the major tasks in ecology and conservation science. In ecological and conservation studies, epiphytic cryptogams are usually sampled up to accessible heights in forests. Thus, their diversity, especially of canopy specialists, likely is underestimated. If the proportion of those species differs among forest types, plot-based diversity assessments are biased and may result in misleading conservation recommendations. We sampled bryophytes and lichens in 30 forest plots of 20 m × 20 m in three German regions, considering all substrates, and including epiphytic litter fall. First, the sampling of epiphytic species was restricted to the lower 2 m of trees and shrubs. Then, on one representative tree per plot, we additionally recorded epiphytic species in the crown, using tree climbing techniques. Per tree, on average 54% of lichen and 20% of bryophyte species were overlooked if the crown was not been included. After sampling all substrates per plot, including the bark of all shrubs and trees, still 38% of the lichen and 4% of the bryophyte species were overlooked if the tree crown of the sampled tree was not included. The number of overlooked lichen species varied strongly among regions. Furthermore, the number of overlooked bryophyte and lichen species per plot was higher in European beech than in coniferous stands and increased with increasing diameter at breast height of the sampled tree. Thus, our results indicate a bias of comparative studies which might have led to misleading conservation recommendations of plot-based diversity assessments. PMID:24358373

  7. Up in the tree--the overlooked richness of bryophytes and lichens in tree crowns.

    Science.gov (United States)

    Boch, Steffen; Müller, Jörg; Prati, Daniel; Blaser, Stefan; Fischer, Markus

    2013-01-01

    Assessing diversity is among the major tasks in ecology and conservation science. In ecological and conservation studies, epiphytic cryptogams are usually sampled up to accessible heights in forests. Thus, their diversity, especially of canopy specialists, likely is underestimated. If the proportion of those species differs among forest types, plot-based diversity assessments are biased and may result in misleading conservation recommendations. We sampled bryophytes and lichens in 30 forest plots of 20 m × 20 m in three German regions, considering all substrates, and including epiphytic litter fall. First, the sampling of epiphytic species was restricted to the lower 2 m of trees and shrubs. Then, on one representative tree per plot, we additionally recorded epiphytic species in the crown, using tree climbing techniques. Per tree, on average 54% of lichen and 20% of bryophyte species were overlooked if the crown was not been included. After sampling all substrates per plot, including the bark of all shrubs and trees, still 38% of the lichen and 4% of the bryophyte species were overlooked if the tree crown of the sampled tree was not included. The number of overlooked lichen species varied strongly among regions. Furthermore, the number of overlooked bryophyte and lichen species per plot was higher in European beech than in coniferous stands and increased with increasing diameter at breast height of the sampled tree. Thus, our results indicate a bias of comparative studies which might have led to misleading conservation recommendations of plot-based diversity assessments.

  8. How climate, migration ability and habitat fragmentation affect the projected future distribution of European beech.

    Science.gov (United States)

    Saltré, Frédérik; Duputié, Anne; Gaucherel, Cédric; Chuine, Isabelle

    2015-02-01

    Recent efforts to incorporate migration processes into species distribution models (SDMs) are allowing assessments of whether species are likely to be able to track their future climate optimum and the possible causes of failing to do so. Here, we projected the range shift of European beech over the 21st century using a process-based SDM coupled to a phenomenological migration model accounting for population dynamics, according to two climate change scenarios and one land use change scenario. Our model predicts that the climatically suitable habitat for European beech will shift north-eastward and upward mainly because (i) higher temperature and precipitation, at the northern range margins, will increase survival and fruit maturation success, while (ii) lower precipitations and higher winter temperature, at the southern range margins, will increase drought mortality and prevent bud dormancy breaking. Beech colonization rate of newly climatically suitable habitats in 2100 is projected to be very low (1-2% of the newly suitable habitats colonised). Unexpectedly, the projected realized contraction rate was higher than the projected potential contraction rate. As a result, the realized distribution of beech is projected to strongly contract by 2100 (by 36-61%) mainly due to a substantial increase in climate variability after 2050, which generates local extinctions, even at the core of the distribution, the frequency of which prevents beech recolonization during more favourable years. Although European beech will be able to persist in some parts of the trailing edge of its distribution, the combined effects of climate and land use changes, limited migration ability, and a slow life-history are likely to increase its threat status in the near future. © 2014 John Wiley & Sons Ltd.

  9. Tree Contractions and Evolutionary Trees

    OpenAIRE

    Kao, Ming-Yang

    2001-01-01

    An evolutionary tree is a rooted tree where each internal vertex has at least two children and where the leaves are labeled with distinct symbols representing species. Evolutionary trees are useful for modeling the evolutionary history of species. An agreement subtree of two evolutionary trees is an evolutionary tree which is also a topological subtree of the two given trees. We give an algorithm to determine the largest possible number of leaves in any agreement subtree of two trees T_1 and ...

  10. The Investigation of Acoustic Properties of Carbon Fiber-Polyester Composites and Comparing the Results with Poplar, Walnut and Beech Wood Specimens

    Directory of Open Access Journals (Sweden)

    Amir soheil Pirayeshfar

    2011-12-01

    Full Text Available In this paper, regarding the high capability of polymeric composites as a substitute of the wood in musical instruments, the acoustic properties of carbon fiber-polyester composites, such as elastic modulus, acoustic coefficient, acoustic coefficient efficiency etc, were investigated using free longitudinal and flexural vibration non-destructive tests and forced vibration non-destructive test. For better understanding, three wooden samples of poplar, walnut and beech trees (frequently used in the manufacturing of musical instruments were chosen and analyzed. Comparing the results showed that the resultant composites had essential acoustic and vibrational properties higher than those of wood samples. Ultrasonic velocity and elastic modulus in longitudinal direction of carbon composites were approximately 11300 m/s and 130GPa, respectively. Besides, the damping results of carbon composites are magnificent and far better than those of the wood specimens.

  11. Aluminum solubility and mobility in relation to organic carbon in surface soils affected by six tree species of the northeastern United States

    NARCIS (Netherlands)

    Dijkstra, F.A.; Fitzhugh, R.D.

    2003-01-01

    We compared Al solubility and mobility in surface soils among six tree species (sugar maple [Acer saccharum], white ash [Fraxinus americana], red maple [Acer rubrum, L.], American beech [Fagus grandifolia, Ehrh.], red oak [Quercus rubra, L.], and hemlock [Tsuga canadensis, Carr.]) in a mixed

  12. Temperature responses of growth and wood anatomy in European beech saplings grown in different carbon dioxide concentrations.

    Science.gov (United States)

    Overdieck, Dieter; Ziche, Daniel; Böttcher-Jungclaus, Kerstin

    2007-02-01

    Effects of temperature on growth and wood anatomy were studied in young European beech (Fagus sylvatica L.) grown in 7-l pots for 2.5 years in field-phytotron chambers supplied with an ambient (approximately 400 micromol mol-1) or elevated (approximately 700 micromol mol-1) carbon dioxide concentration ([CO2]). Temperatures in the chambers ranged in increments of 2 degrees C from -4 degrees C to +4 degrees C relative to the long-term mean monthly (day and night) air temperature in Berlin-Dahlem. Soil was not fertilized and soil water and air humidity were kept constant. Data were evaluated by regression analysis. At final harvest, stem diameter was significantly greater at increased temperature (Delta1 degrees C: 2.4%), stems were taller (Delta1 degrees C: 8.5%) and stem mass tree-1 (Delta1 degrees C: 10.9%) and leaf area tree-1(Delta1 degrees C: 6.5%) were greater. Allocation pattern was slightly influenced by temperature: leaf mass ratio and leaf area ratio decreased with increasing temperature (Delta1 degrees C: 2.3% and 2.2% respectively), whereas stem mass/total mass increased (Delta1 degrees C: 2.1%). Elevated [CO2] enhanced height growth by 8.8% and decreased coarse root mass/total mass by 10.3% and root/shoot ratio by 11.7%. Additional carbon was mainly invested in aboveground growth. At final harvest a synergistic interaction between elevated [CO2] and temperature yielded trees that were 3.2% taller at -4 degrees C and 12.7% taller at +4 degrees C than trees in ambient [CO2]. After 2.5 seasons, cross-sectional area of the oldest stem part was approximately 32% greater in the +4 degrees C treatment than in the -4 degrees C treatment, and in the last year approximately 67% more leaf area/unit tree ring area was produced in the highest temperature regime compared with the lowest. Elevated [CO2] decreased mean vessel area of the 120 largest vessels per mm2 by 5.8%, causing a decrease in water conducting capacity. There was a positive interaction between

  13. Population dynamics of the felted beech scale and associated Neonectria species, causal agents of beech bark disease

    Science.gov (United States)

    Jeffrey Garnas; David Houston; Matthew Ayres; Celia Evans

    2009-01-01

    Biotic threats to tree growth, survival, or reproduction often arise from interactions among a suite of species, primarily insects and fungi, that function together to varying degrees to defeat host defenses, secure resources, and infect...

  14. Decomposition of beech (Fagus sylvatica) and pine (Pinus nigra) litter along an Alpine elevation gradient: Decay and nutrient release.

    Science.gov (United States)

    Berger, Torsten W; Duboc, Olivier; Djukic, Ika; Tatzber, Michael; Gerzabek, Martin H; Zehetner, Franz

    2015-08-01

    Litter decomposition is an important process for cycling of nutrients in terrestrial ecosystems. The objective of this study was to evaluate direct and indirect effects of climate on litter decomposition along an altitudinal gradient in a temperate Alpine region. Foliar litter of European beech ( Fagus sylvatica ) and Black pine ( Pinus nigra ) was incubated in litterbags during two years in the Hochschwab massif of the Northern Limestone Alps of Austria. Eight incubation sites were selected following an altitudinal/climatic transect from 1900 to 900 m asl. The average remaining mass after two years of decomposition amounted to 54% (beech) and 50% (pine). Net release of N, P, Na, Al, Fe and Mn was higher in pine than in beech litter due to high immobilization (retention) rates of beech litter. However, pine litter retained more Ca than beech litter. Altitude retarded decay (mass loss and associated C release) in beech litter during the first year only but had a longer lasting effect on decaying pine litter. Altitude comprises a suite of highly auto-correlated characteristics (climate, vegetation, litter, soil chemistry, soil microbiology, snow cover) that influence litter decomposition. Hence, decay and nutrient release of incubated litter is difficult to predict by altitude, except during the early stage of decomposition, which seemed to be controlled by climate. Reciprocal litter transplant along the elevation gradient yielded even relatively higher decay of pine litter on beech forest sites after a two-year adaptation period of the microbial community.

  15. Effect of particle geometry and micro-structure on fast pyrolysis of beech wood

    NARCIS (Netherlands)

    Westerhof, Roel Johannes Maria; Nygard, H.; van Swaaij, Willibrordus Petrus Maria; Kersten, Sascha R.A.; Brilman, Derk Willem Frederik

    2012-01-01

    The influence of particle geometry and microstructure in fast pyrolysis of beech wood has been investigated. Milled wood particles (<0.08–2.4 mm) and natural wood cylinders (2–14 mm) with different lengths (10–50 mm) and artificial wood cylinders (Dp = 0.5–14 mm) made of steel walls, filled with

  16. Mapping beech (Fagus sylvatica L.) forest structure with airborne hyperspectral imagery

    CSIR Research Space (South Africa)

    Cho, Moses A

    2009-06-01

    Full Text Available improvement in estimating the beech forest structural attributes compared to NDVI using linear regression models. Mean DBH was the best predicted variable among the stand parameters (calibration R2 = 0.62 for an exponential model fit and standard error...

  17. Chilocorus stigma (Coleoptera: Coccinellidae) and other predators of beech scale in central New York

    Science.gov (United States)

    Mark Mayer; Douglas C. Allen

    1983-01-01

    The twice-stabbed lady beetle Chilocorus stigma (Say), was studied in two infestations of beech scale, Cryptococccus fagisuga Lind., to elucidate predator biology and to determine the predator's effect on scale populations. C. stigma is univoltine in north-central regions of New York and its seasonal...

  18. The influence of regeneration fellings on the development of artificially regenerated beech (Fagus sylvatica L.) plantations

    Czech Academy of Sciences Publication Activity Database

    Bednář, Pavel; Černý, J.

    2014-01-01

    Roč. 62, č. 5 (2014), s. 859-867 ISSN 1211-8516 Institutional support: RVO:67179843 Keywords : European beech * regeneration felling * artificial regeneration * height * DBH – the diameter at breast-height * quality * ISF – Indirect Site Factor Subject RIV: GK - Forestry

  19. Plastic Growth response of European beech provenances to dry site conditions

    NARCIS (Netherlands)

    Stojnic, S.; Sass, U.G.W.; Orlovic, S.; Matovic, B.; Eilmann, B.

    2013-01-01

    Due to projected global warming, there is a great concern about the ability of European beech to adapt to future climate conditions. Provenance trials provide an excellent basis to assess the potential of various provenances to adjust to given climate conditions. In this study we compared the

  20. Steel-to-timber joints of beech-lvl with very high strength steel dowels

    NARCIS (Netherlands)

    Misconel, A.; Ballerini, M.; van de Kuilen, J.W.G.; Eberhardsteiner, J.; Winter, W.; Fadai, A.; Pöll, M.

    2016-01-01

    Double-shear steel-to-timber joints of beech laminated veneer lumber (LVL) with slotted-in steel plates using very high strength steel (VHSS) dowels have been investigated. Tensile tests on full-scale joints with one, two, three and six dowels have been carried out,

  1. Signals from beech (Fagus sylvatica L.) in response to precipitation extremes - flowering induction and reduced foliation

    DEFF Research Database (Denmark)

    Callesen, Ingeborg

    Reduced foliation in older (but also young) beech (Fagus sylvatica L.) stands was observed in Denmark in the mid 1990ies and culminated with the 1996 summer drought and heat wave. Large differences in the degree of reduced foliation between regions and within stands were observed e.g. reflecting...

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

    NARCIS (Netherlands)

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

    2003-01-01

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

  3. Methanol and other VOC fluxes from a Danish beech forest during late springtime

    DEFF Research Database (Denmark)

    Schade, Gunnar W.; Solomon, Sheena J.; Dellwik, Ebba

    2011-01-01

    occurred during both day and night with highest fluxes (0.2 mg C m−2 h−1) during a warm period; deposition occurred dominantly at daytime. Confirming previous branch-level measurements on beech, the forest’s monoterpene emissions (0–0.5 mg C m−2 h−1), and in-canopy mixing ratios showed a diurnal cycle...

  4. The yeast flora of some decaying mushrooms on trunks of living trees

    OpenAIRE

    Middelhoven, W.J.

    2004-01-01

    Several ascomycetous and basidiomycetous yeasts were isolated from rotten mushrooms on the trunks of beech and tamarisk trees. One strain, identified as the novel species Cryptococcus allantoinivorans, assimilated allantoin as the sole carbon source. Phylogenetically it belongs to the C. laurentii complex, Papiliotrema bandonii being the closest relative. Some ascomycetous strains could not be distinguished from Pichia guillermondii, but deviated considerably in rDNA sequences. In addition to...

  5. Future of Beech in Southeast Europe from the Perspective of Evolutionary Ecology

    Directory of Open Access Journals (Sweden)

    MÁTYÁS, Csaba

    2010-01-01

    Full Text Available The aim of this study is to provide quantitative information on the effect of climaticchange on the growth and vitality of European beech: although the species is considered in itsoptimum highly plastic and adaptable, it becomes climate-sensitive closer to its xeric (lowerdistribution limits. The future of beech in Southeast Europe requires special attention because thisregion harbours significant populations living at or near their xeric distribution boundary. Even thoughthe low elevation occurrences are uniquely vulnerable to climatic shifts, observations and modellingstudies pertaining to this region are particularly scarce.Out of climatic factors determining the xeric distributional limits for beech, Ellenberg’s droughtindex (EQ appeared as the most influential. Growth response analyses in comparative tests haveconfirmed the existence of macroclimatic adaptation of beech and have proven that warming and morearid conditions lead to decline of growth and vitality, while no decline was observed if EQ changed inthe opposite direction. The response to weather extremes was investigated in field plots. Recurrentsummer droughts of 3 to 4 consecutive years, above mean EQ value 40-42 resulted in pest and diseaseattacks and mass mortality.The discussed approaches indicate consistently a high level of uncertainty regarding the future ofbeech at the xeric limit in Southeast Europe. According to field observations and bioclimatic data inHungary, a large part of low-elevation beech forests presently in the zone of EQ index 20 might bethreatened by the warming in the second half of the century, while higher-elevation occurrences mayremain stable.The interpretation of the results bears some stipulations, such as the consequence of ecologicaland human interactions in influencing present distribution patterns, the unclear role of persistence,natural selection and plasticity and uncertainties of climate projections. Grim projections mayprobably be partly

  6. Carbon and nitrogen in forest floor and mineral soil under six common European tree species

    DEFF Research Database (Denmark)

    Vesterdal, Lars; Schmidt, Inger K.; Callesen, Ingeborg

    2007-01-01

    The knowledge of tree species effects on soil C and N pools is scarce, particularly for European deciduous tree species. We studied forest floor and mineral soil carbon and nitrogen under six common European tree species in a common garden design replicated at six sites in Denmark. Three decades...... after planting the six tree species had different profiles in terms of litterfall, forest floor and mineral soil C and N attributes. Three groups were identified: (1) ash, maple and lime, (2) beech and oak, and (3) spruce. There were significant differences in forest floor and soil C and N contents...... and C/N ratios, also among the five deciduous tree species. The influence of tree species was most pronounced in the forest floor, where C and N contents increased in the order ash = lime = maple soil only in some of the sampled soil layers within 30...

  7. Microwave sensing of tree trunks

    Science.gov (United States)

    Jezova, Jana; Mertens, Laurence; Lambot, Sebastien

    2015-04-01

    was divided into three sections to separate parts with different moisture (heartwood and sapwood) or empty space (decays). For easier manipulation with the antenna we developed a special ruler for measuring the distance along the scans. Instead of the surveying wheel we read the distance with a camera, which was fixed on the antenna and focused on the ruler with a binary pattern. Hence, during whole measurement and the data processing we were able to identify an accurate position on the tree in view of the scan. Some preliminary measurements on the trees were also conducted. They were performed using a GSSI 900 MHz antenna. Several tree species (beech, horse-chestnut, birch, ...) in Louvain-la-Neuve and Brussels, Belgium, have been investigated to see the internal structure of the tree decays. The measurements were carried out mainly by circumferential measurement around the trunk and also by vertical measurement along the trunk for approximate detection of the cavity. The comparison between the numerical simulations, simplified tree trunk model and real data from trees is presented. This research is funded by the Fonds de la Recherche Scientifique (FNRS, Belgium) and benefits from networking activities carried out within the EU COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar".

  8. Seasonal and inter-annual dynamics of growth, non-structural carbohydrates and C stable isotopes in a Mediterranean beech forest.

    Science.gov (United States)

    Scartazza, Andrea; Moscatello, Stefano; Matteucci, Giorgio; Battistelli, Alberto; Brugnoli, Enrico

    2013-07-01

    Seasonal and inter-annual dynamics of growth, non-structural carbohydrates (NSC) and carbon isotope composition (δ(13)C) of NSC were studied in a beech forest of Central Italy over a 2-year period characterized by different environmental conditions. The net C assimilated by forest trees was mainly used to sustain growth early in the season and to accumulate storage carbohydrates in trunk and root wood in the later part of the season, before leaf shedding. Growth and NSC concentration dynamics were only slightly affected by the reduced soil water content (SWC) during the drier year. Conversely, the carbon isotope analysis on NSC revealed seasonal and inter-annual variations of photosynthetic and post-carboxylation fractionation processes, with a significant increase in δ(13)C of wood and leaf soluble sugars in the drier summer year than in the wetter one. The highly significant correlation between δ(13)C of leaf soluble sugars and SWC suggests a decrease of the canopy C isotope discrimination and, hence, an increased water-use efficiency with decreasing soil water availability. This may be a relevant trait for maintaining an acceptable plant water status and a relatively high C sink capacity during dry seasonal periods. Our results suggest a short- to medium-term homeostatic response of the Collelongo beech stand to variations in water availability and solar radiation, indicating that this Mediterranean forest was able to adjust carbon-water balance in order to prevent C depletion and to sustain plant growth and reserve accumulation during relatively dry seasons.

  9. Wood quality and value production in mixed fir-spruce-beech stands: long-term research in the Western Carpathians

    Directory of Open Access Journals (Sweden)

    Petráš Rudolf

    2016-06-01

    Full Text Available Stem quality and damage was evaluated in mixed spruce-fir-beech stands. Moreover, an assortments structure was determined with their financial value. Results were compared with pure spruce (Picea abies [L.] Karst., fir (Abies alba Mill. and beech (Fagus sylvatica L. stands. Repeated measurements on 31 long-term research plots, stand assortment models, assortment yield models and value yield models were used. Stem quality of fir and spruce was only slightly lower in mixed stands compared to pure stands but beech stem quality was considerably worse in mixed stands. Fir and spruce had slightly lower proportions of better IIIA quality logs and higher proportions of IIIB quality in mixed stands. Beech had worse assortment structure than spruce and fir, in general. Pure beech stands had higher proportions of better I–IIIA quality assortments than mixed stands by 1–7%. Fir and spruce average value production (€ m−3 culminated at about 56 and 62 cm mean diameters. Almost the same value production was found in pure stands. In these stands it culminated at the mean diameter of 58 and 60 cm. Beech produced substantially less value on the same sites. In mixed stands, its value production culminated at the mean diameter of 40 cm. In pure stands, it culminated at the mean diameter of 36 cm. Although the production was found to be similar in both mixed and pure forests, higher damage intensity and less stem quality in mixed forests suggest that the pure forests can be more profitable.

  10. Native fauna on exotic trees: phylogenetic conservatism and geographic contingency in two lineages of phytophages on two lineages of trees.

    Science.gov (United States)

    Gossner, Martin M; Chao, Anne; Bailey, Richard I; Prinzing, Andreas

    2009-05-01

    The relative roles of evolutionary history and geographical and ecological contingency for community assembly remain unknown. Plant species, for instance, share more phytophages with closer relatives (phylogenetic conservatism), but for exotic plants introduced to another continent, this may be overlaid by geographically contingent evolution or immigration from locally abundant plant species (mass effects). We assessed within local forests to what extent exotic trees (Douglas-fir, red oak) recruit phytophages (Coleoptera, Heteroptera) from more closely or more distantly related native plants. We found that exotics shared more phytophages with natives from the same major plant lineage (angiosperms vs. gymnosperms) than with natives from the other lineage. This was particularly true for Heteroptera, and it emphasizes the role of host specialization in phylogenetic conservatism of host use. However, for Coleoptera on Douglas-fir, mass effects were important: immigration from beech increased with increasing beech abundance. Within a plant phylum, phylogenetic proximity of exotics and natives increased phytophage similarity, primarily in younger Coleoptera clades on angiosperms, emphasizing a role of past codiversification of hosts and phytophages. Overall, phylogenetic conservatism can shape the assembly of local phytophage communities on exotic trees. Whether it outweighs geographic contingency and mass effects depends on the interplay of phylogenetic scale, local abundance of native tree species, and the biology and evolutionary history of the phytophage taxon.

  11. Impact of tree species on soil carbon stocks and soil acidity in southern Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Oostra, Swantje [Swedish Univ. of Agricultural Sciences, Alnarp (Sweden). Dept. of Landscape Planning; Majdi, Hooshang [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Sciences; Olsson, Mats [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Soils

    2006-10-15

    The impact of tree species on soil carbon stocks and acidity in southern Sweden was studied in a non-replicated plantation with monocultures of 67-year-old ash (Fraxinus excelsior L.), beech (Fagus silvatica L.), elm (Ulmus glabra Huds.), hornbeam (Carpinusbetulus L.), Norway spruce (Picea abies L.) and oak (Quercus robur L.). The site was characterized by a cambisol on glacial till. Volume-determined soil samples were taken from the O-horizon and mineral soil layers to 20 cm. Soil organic carbon (SOC), total nitrogen (TN), pH (H2O), cation-exchange capacity and base saturation at pH 7 and exchangeable calcium, magnesium, potassium and sodium ions were analysed in the soil fraction < 2 mm. Root biomass <5 mm in diameter) and its proportion in the forest floor and mineral soil varied between tree species. There was a vertical gradient under all species, with the highest concentrations of SOC, TN and base cations in the O-horizon and the lowest in the 10-20 cm layer. The tree species differed with respect to SOC, TN and soil acidity in the O-horizon and mineral soil. For SOC and TN, the range in the O-horizon was spruce> hornbeam > oak > beech > ash > elm. The pH in the O-horizon ranged in the order elm > ash > hornbeam > beech > oak > spruce. In the mineral soil, SOC and TN ranged in the order elm > oak > ash = hornbeam > spruce > beech, i.e. partly reversed, and pH ranged in the same order as for the O-horizon. It is suggested that spruce is the best option for fertile sites in southern Sweden if the aim is a high carbon sequestration rate, whereas elm, ash and hornbeam are the best solutions if the aim is a low soil acidification rate.

  12. Patterns of drought tolerance in major European temperate forest trees: climatic drivers and levels of variability.

    Science.gov (United States)

    Zang, Christian; Hartl-Meier, Claudia; Dittmar, Christoph; Rothe, Andreas; Menzel, Annette

    2014-12-01

    The future performance of native tree species under climate change conditions is frequently discussed, since increasingly severe and more frequent drought events are expected to become a major risk for forest ecosystems. To improve our understanding of the drought tolerance of the three common European temperate forest tree species Norway spruce, silver fir and common beech, we tested the influence of climate and tree-specific traits on the inter and intrasite variability in drought responses of these species. Basal area increment data from a large tree-ring network in Southern Germany and Alpine Austria along a climatic cline from warm-dry to cool-wet conditions were used to calculate indices of tolerance to drought events and their variability at the level of individual trees and populations. General patterns of tolerance indicated a high vulnerability of Norway spruce in comparison to fir and beech and a strong influence of bioclimatic conditions on drought response for all species. On the level of individual trees, low-growth rates prior to drought events, high competitive status and low age favored resilience in growth response to drought. Consequently, drought events led to heterogeneous and variable response patterns in forests stands. These findings may support the idea of deliberately using spontaneous selection and adaption effects as a passive strategy of forest management under climate change conditions, especially a strong directional selection for more tolerant individuals when frequency and intensity of summer droughts will increase in the course of global climate change. © 2014 John Wiley & Sons Ltd.

  13. The potential of beech seedlings to adapt to low P availability in soil - plant versus microbial effects on P mobilising potential in the rhizosphere

    Science.gov (United States)

    Meller, Sonia; Frey, Beat; Frossard, Emmanuel; Spohn, Marie; Schack-Kirchner, Helmer; Luster, Jörg

    2016-04-01

    The objective of our work was to investigate to what extent tree seedlings (Fagus sylvatica) are able to adapt the process of P mobilisation in the rhizosphere according to P speciation in the soil. Such mobilisation activity can include root exudation of P mobilising compounds or stimulation of specific P mobilising soil microbes. We hypothesized that Fagus sylvatica seedlings can adapt their own activity based on their P nutritional status and genetic memory of how to react under a given nutritional situation. To test the hypothesis, we set up a cross-growth experiment with beech of different provenances growing in soil from their own provenance site and in soil differing in P availability. Experiments were performed as a greenhouse experiment, with temperature control and natural light, during one vegetation period in rhizoboxes . We used two acidic forest soils, contrasting in P availability, collected at field sites of the German research priority program "Ecosystem Nutrition". Juvenile trees were collected along with the soils at the sites and planted respectively. The occurrence of P mobilising compounds and available P in the rhizosphere and in bulk soil were measured during the active growth season of the plants. In particular, we assessed phosphatase activity, (measured with zymography and plate enzymatic assay at pH 4,6.5, and 11) carboxylates and phosphate (measured by application of ion exchange membranes to specific soil micro zones, and by microdialysis), and pH (mapping with optodes). Plant P nutrition status was assessed by total P, N/P, phosphatase activity, and metabolic (TCA extractable) P in the leaves. The P-nutritional status of the beech provenances differed markedly independent from the P status of the soil where they were actually grown during experiment. In particular, the juvenile trees from the site rich in mineral P were sufficient in P, while those from the P-poor site with mostly organic P, were deficient. Enzymatic activity at the

  14. Flowering Trees

    Indian Academy of Sciences (India)

    Dolichandrone atrovirens (Roth) K. Schum. (Spathe Trumpet Tree) of Bignoniaceae is a medium-sized handsome tree with a straight bole that branches at the top. Leaves are once pinnate, with two to three pairs of leaflets. Young parts of the tree are velvety. Inflorescence is a branched raceme borne at the branch ends.

  15. Nematode communities of natural and managed beech forests - a pilot study

    DEFF Research Database (Denmark)

    Strandmark, Lisa Bjørnlund; Madsen, Mette Vestergård; Johansson, Sanne

    2002-01-01

    was found in a Canonical Community Ordination (CANOCO) that related nematode data and various soil parameters in each sample. Beech forests of Mid-Zealand (Suserup) had significantly lower sand content, higher pH, higher PPI and higher nematode diversity according to the Shannon-index than the forests...... of North Zealand (Farum and Rankeskov). A distinct difference in the distribution of families was observed between sites, which could be governed by differences in texture and pH. The MI of the two old natural forest sites (Farum and Suserup) was significantly higher than the comparable managed sites......, while this was not the case for Rankeskov, which is in a less mature state. There was a significantly higher adult/juvenile ratio and higher relative abundance of bacterial feeders in the natural forests compared to the managed forests. The apparent relation between pH and Maturity Index in beech...

  16. EXPERIMENTAL RESEARCH CONCERNING THE OPTIMAL DIMENSIONS OF AN ELASTIC STRUCTURE OF BEECH WOOD PARQUET

    Directory of Open Access Journals (Sweden)

    Olimpia-Minerva ȚURCAȘ (DIACONU

    2015-12-01

    Full Text Available This paper presents the results of the experimental research concerning the modulus of elasticity and the average value of the bending strength in case of beech (Fagus sylvatica L. wood. The investigations were performed according to SR EN 408-2004. The results of the research have been analysed in order to establish the variable parameters to be considered for the final experimental research focused on beech wood floor structures that meet the necessary requirements for the sports halls applications. The research presented in the paper is a part of the study theme of the Ph. D. thesis, which investigates the flooring structures able to support the requirements of sports halls activities, different from one sport to another.

  17. Effect furfurylation on physical properties and surface quality of two species of Beech and Fir

    Directory of Open Access Journals (Sweden)

    aysona talai

    2016-12-01

    Full Text Available The objective of this study was investigation of furfurylation effect on water absorption, thickness swelling, contact angle and surface roughness in two species such as beech (Fagus orientalis and fir (Abies alba. In this regard, two different values of furfurylation of beech and fir wood specimens in the form of low level and high level were carried out and compared with control specimens. The furfurylation was carried out with impregnation under pressure and polymerization of furfuryl alcohol monomer with heat catalyst. For evaluating the water absorption and thickness swelling, specimens were subjected to long-term water immersion, and their dimension changes were determined at different times. The surface roughness and contact angle testes were also carried out. Results indicated that water absorption and thickness swelling were reduced. Results also indicated that drop contact angles were decreased and surface roughness were increased by increasing of furfurylation level.

  18. CULTIVATION OF P. FLORIDA SUPLEMENTED OF RICE BRAIN ON BEECH WOOD WASTE

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    Hüseyin SİVRİKAYA

    1998-03-01

    Full Text Available Cultivation of Pleurotus spp. reached to the second largest in amount after Agaricus bisporus (Lange sing. in the world. There recently has also been growing interest to cultivate them on wastes of forest and agricultural plants in Turkey. In the scope of study Pleurotus florida was produced on beech wood sawmill waste and rice brain. Beech wood sawmill waste (Fagus orientalis Lipsky were used as main substrate and supplemented with rice brain as co-substrate by 10 % W/W, 0 % W/W, 40 % W/W mixing ratios based on dry weights. To produce P. florida substrates were ground, air dried, moistured up to 70-80 % by tap water, supplemented, pasteurized with live steam and spawned. Highest yields (440 gr/kg of P. florida were obtained by supplementing wood waste and rice brain (% 80 + % 20. Furthermore, the best mycelia development were obtained by % 90 + % 10.

  19. Decomposition, nitrogen and phosphorus mineralization from beech leaf litter colonized with ectomycorrhizal or litter decomposing basidiomycetes

    OpenAIRE

    COLPAERT, Jan; VAN TICHELEN, Katia

    1996-01-01

    The decomposition and the nitrogen and phosphorus mineralization of fresh beech (Fagus sylvatica L.) leaf litter are described. Leaves were buried for up to 6 months in plant containers in which Scots pine (Pinus sylvestris L.) seedlings were cultivated at a low rate of nutrient addition. The saprotrophic abilities of three ectomycorrhizal fungi, Thelephora terrestris Ehrh.: Fr., Suillus bovinus (L.: Fr.) O. Kuntze and Paxillus involutes (Batsch: Fr) Fr., were compared with the degradation ca...

  20. Waste heaps left by historical Zn-Pb ore mining are hotspots of species diversity of beech forest understory vegetation.

    Science.gov (United States)

    Woch, Marcin W; Stefanowicz, Anna M; Stanek, Małgorzata

    2017-12-01

    Metalliferous mining and smelting industries are associated with very high levels of heavy metal(loid) contamination of the environment. Heavy metals have been proved to significantly influence the species diversity and composition of grassland communities, but little is known on their effects on forest understory vegetation. Therefore, the aim of this study was to investigate the effects of the presence of small heaps of waste rock left by historical Zn-Pb ore mining on understory vegetation. The heaps are scattered over vast areas of beech forests in southern Poland. Three types of study plots were established: (1) on waste heaps themselves, (2) in their vicinity (5-10m from the foot of the heaps, with no waste rock but potentially influenced by the heaps through drainage water), and (3) at least 100m from the foot of the heaps (pseudo-control). In all plots vegetation parameters, i.e., plant species number, cover and community composition, life forms and strategies, as well as basic soil properties were assessed. Although the heaps contained high concentrations of metals, namely Cd, Pb and Zn, they were characterised by higher cover and diversity of understory vegetation, including ancient forest and endangered species, in comparison to their surroundings. They were also characterised by the distinct species composition of their plant communities. This might have resulted from the beneficial influence of high pH and Ca content originating from waste rock composed of dolomite and calcite, as well as from increased habitat heterogeneity, e.g. soil skeleton and steeper slopes. Another important factor influencing the richness and composition of understory was tree cover, which relates to the light transmissibility of the canopy. Our study proved that the disturbance brought about by the former mining and processing of metal ores led to the formation of species-rich understory with high frequency and cover of naturally-valuable species. Copyright © 2017 Elsevier B

  1. Leaf morphometric characteristics variability of different beech provenances in juvenile development stage

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    Šijačić-Nikolić Mirjana

    2013-01-01

    Full Text Available The taxonomic status of beech from the Balkan Peninsula is not yet clearly defined. There is no agreement among different authors about the morphological characteristics discriminating between the Balkan and European and/or Eastern beech. For most characteristics, the mean values are different but the ranges of variation overlap considerably. Provenance trial of beech established in Serbia, at the locality Debeli Lug, has provided an opportunity for research of interprovenance variability at the level of leaf morphometric characteristics in juvenile development stage. Research included 10 provenances originating from the Western Balkans (Serbian provenance 36 and 38; Croatian provenance 24 and 25; Bosnian provenance 30 and 32 and from Central Europe (German provenance 47 and 49; Austrian provenance 56 and Hungarian provenance 42, where following morphometric characteristics were analyzed: leaf length (Ll, leaf width (Lw, petiole lenght (Pl, leaf base width on 1 cm (Blw, number of veins - left (Vl, number of veins - right (Vr, distance between 3rd and 4th vein - left (Dv 3-4. The results of this research show existence of clear differentiation among provenances from the Western Balkan and from Central Europe, from the point of leaf dimensions, number of veins and leaf base width. [Projekat Ministarstva nauke Republike Srbije, br. TR31041: Establishment of Wood Plantations Intended for Afforestation of Serbia i br. 43007: Studying climate change and its influence on the environment: impacts, adaptation and mitigation

  2. Ground level ozone effects in individual growth phases of central european submountain beech forests

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    Kellerová Daniela

    2014-03-01

    Full Text Available We observed ground level ozone concentrations on a series of five beech experimental plots, one representing the original stand and the other four generated and modified by cuts of graduated intensity. The study was carried out in a beech ecosystem in the Kremnické vrchy Mts, the Western Carpathian region, in years 1999-2008. The plots, established in 1989, were evaluated and compared statistically before and after the cutting modification in 2004. The level of significance of the effect of this intervention was 99% on the plot representing small-area clear-cut and on the plot treated with medium cut. Differences, though not significant, were also found in the other plots. Apart from the effects due to the stocking reduction, the whole post-intervention period was characterised with the influence of progressively increasing average air temperatures and similarly increasing ozone concentrations. Globally, the ozone concentrations on all plots were lower (average value 39 μg m-3 during the period 1999-2003 than in the following years 2004-2008 (average value 55 μg m-3. Maximum values measured in the growing season ranged from 36 to 140 μg m-3. The allowable limit exceeded 10 times in years 1999-2003 but 17 times in years 2004-2008, implying worsening conditions in Central European beech forest stands.

  3. The role of extreme drought events in modelling the distribution of beech at its xeric limit

    Science.gov (United States)

    Rasztovits, Ervin; Berki, Imre; Eredics, Attila; Móricz, Norbert

    2014-05-01

    Context: Projections of species distribution models (SDMs) for future climate conditions are based on long term mean climate data. For management and conservation issues SDMs have been extensively used, but it is not tested whether models that are successful in predicting current distributions are equally powerful in predicting distributions under future climates. Methods: Observations after 2003 confirms that extreme drought events played an important role in driving beech mortality at low-elevation xeric limits. The objective of this study was (1) to set up a simple extreme drought event based vitality model (EDM) using sanitary logging information as a proxy of vitality response of beech and (2) to compare the spatial pattern of the predicted vitality loss provided by the EDM with the distribution limits of the SDMs for three terms (2025, 2050 and 2100) in Hungary to assess model performance. Results: Prediction for vitality loss for 2025 obtained from the EDM was in agreement with those of the SDM, but for the end of the century the EDM predicted a more serious decline in almost all regions of Hungary. Conclusion: The result of the comparison suggests that the increasing frequency and severity of extremes might play a more important role in limiting the distribution of beech in the future near to the xeric limit than long-term means.

  4. Extra-zonal beech forests in Tuscany: structure, diversity and synecologic features

    Directory of Open Access Journals (Sweden)

    Viciani D

    2011-07-01

    Full Text Available The present paper focuses on the structural, synecological and floristic diversity features of beech-dominated forest communities in four major areas of the Antiapenninic Tyrrhenian system in Tuscany: Metalliferous hills, mountains to the south of Mt. Amiata, volcanic area of the upper Lente valley and Mt. Cetona. These are relict woodlands of Holo-Pleistocene origin with a special ecological and conservation value due to their extrazonal location in lowland submediterranean areas. Results show substantial among-area differences in structure, synecology and plant species composition, but in general a potential for coppices to reach the tall forest stage, as demonstrated by the old-growth stands of Pietraporciana and Sassoforte. Compared with montane Apenninic beechwoods, the relatively rich flora of the studied communities include thermophilous species with a southern Apennine-Balkan distribution, making their syntaxonomical position unclear. Closer affinities are found with the calcicolous Beech Forests of the association and with the silicicolous ones of the . Based on the Natura 2000 system, all the examined communities belong to the priority Habitat “Apennine beech forests with and ” (code: 9210*. Due their relict nature, these biotopes appear vulnerable to climate changes and to a production-oriented forest management. Criteria of naturalistic silviculture should instead promote the dynamic development of these communities towards tall forests and their natural regeneration.

  5. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.

    2013-01-01

    We introduce a new compression scheme for labeled trees based on top trees [3]. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  6. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.

    2015-01-01

    We introduce a new compression scheme for labeled trees based on top trees. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  7. Response patterns in adult forest trees to chronic ozone stress: identification of variations and consistencies

    International Nuclear Information System (INIS)

    Nunn, Angela J.; Reiter, Ilja M.; Haeberle, Karl-Heinz; Langebartels, Christian; Bahnweg, Guenther; Pretzsch, Hans; Sandermann, Heinrich; Matyssek, Rainer

    2005-01-01

    The responsiveness of adult beech and spruce trees to chronic O 3 stress was studied at a free-air O 3 exposure experiment in Freising/Germany. Over three growing seasons, gas exchange characteristics, biochemical parameters, macroscopic O 3 injury and the phenology of leaf organs were investigated, along with assessments of branch and stem growth as indications of tree performance. To assess response pattern to chronic O 3 stress in adult forest trees, we introduce a new evaluation approach, which provides a comprehensive, readily accomplishable overview across several tree-internal scaling levels, different canopy regions and growing seasons. This new approach, based on a three-grade colour coding, combines statistical analysis and the proficient ability of the 'human eye' in pattern recognition. - Responses of adult forest trees to chronic O 3 stress can be visualized in a survey table applying a three-grade colour coding to each investigated parameter

  8. Exemplifying whole-plant ozone uptake in adult forest trees of contrasting species and site conditions

    International Nuclear Information System (INIS)

    Nunn, Angela J.; Wieser, Gerhard; Metzger, Ursula; Loew, Markus; Wipfler, Philip; Haeberle, Karl-Heinz; Matyssek, Rainer

    2007-01-01

    Whole-tree O 3 uptake was exemplified for Picea abies, Fagus sylvatica and Larix decidua in stands at high and low altitude and contrasting water availability through sap flow measurement in tree trunks, intrinsically accounting for drought and boundary layer effects on O 3 flux. O 3 uptake of evergreen spruce per unit foliage area was enhanced by 100% at high relative to low elevation, whereas deciduous beech and larch showed similar uptake regardless of altitude. The responsiveness of the canopy conductance to water vapor and, as a consequence, O 3 uptake to soil moisture and air humidity did not differ between species. Unifying findings at the whole-tree level will promote cause-effect based O 3 risk assessment and modeling. - Sap flow-based assessment of whole-tree O 3 uptake reflects similar responsiveness of canopy conductance and O 3 uptake across contrasting tree species and site conditions

  9. Vapor-pressure deficit and extreme climatic variables limit tree growth.

    Science.gov (United States)

    Sanginés de Cárcer, Paula; Vitasse, Yann; Peñuelas, Josep; Jassey, Vincent E J; Buttler, Alexandre; Signarbieux, Constant

    2018-03-01

    Assessing the effect of global warming on forest growth requires a better understanding of species-specific responses to climate change conditions. Norway spruce and European beech are among the dominant tree species in Europe and are largely used by the timber industry. Their sensitivity to changes in climate and extreme climatic events, however, endangers their future sustainability. Identifying the key climatic factors limiting their growth and survival is therefore crucial for assessing the responses of these two species to ongoing climate change. We studied the vulnerability of beech and spruce to warmer and drier conditions by transplanting saplings from the top to the bottom of an elevational gradient in the Jura Mountains in Switzerland. We (1) demonstrated that a longer growing season due to warming could not fully account for the positive growth responses, and the positive effect on sapling productivity was species-dependent, (2) demonstrated that the contrasting growth responses of beech and spruce were mainly due to different sensitivities to elevated vapor-pressure deficits (VPD), (3) determined the species-specific limits to VPD above which growth rate began to decline, and (4) demonstrated that models incorporating extreme climatic events could account for the response of growth to warming better than models using only average values. These results support that the sustainability of forest trees in the coming decades will depend on how extreme climatic events will change, irrespective of the overall warming trend. © 2017 John Wiley & Sons Ltd.

  10. Subsoil methanogenesis as source of stem CH4 emission in upland forest trees: preferential CH4 transport via the root system?

    Science.gov (United States)

    Maier, M.; Machacova, K.; Urban, O.; Friederike, L.

    2016-12-01

    Quantifying and understanding green house gas fluxes in natural soil-plant-atmosphere systems are crucial to predicting global climate change. Wetland species or trees at waterlogged sites are known to emit large amounts of CH4. Yet upland forest soils are regarded as CH4 sinks and tree species like upland European beech (Fagus sylvatica, L.) are assumed not to emit CH4. We studied the soil-atmosphere and stem-atmosphere fluxes of CH4, and soil gas profiles at two upland beech forest sites in Central Europe. Soil was a net CH4 sink at both. Unusually there was one beech tree with substantial CH4 emissions that were higher than the CH4 sink of the soil. The soil gas profile at this tree indicated CH4 production at a soil depth >0.3 m, despite the net uptake of CH4 observed at the soil surface adjacent to the tree. Field soil assessment showed strong redoximorphic color patterns in the adjacent soil. We think that there is a transport link between the soil and stem via the root system representing a preferential transport mechanism for CH4 despite the fact that beech roots usually do not bear aerenchyma. The gas transport process , either via dissolved CH4 in the xylem water or in the root gas phase, is not yet clear. The observed CH4 stem emissions represent an important CH4flux in this ecosystem, und thus should be considered in future research. AcknowledgementThis research was financially supported by the Czech Academy of Sciences and the German Academic Exchange Service within the project "Methane (CH4) and nitrous oxide (N2O) emissions from Fagus sylvatica trees" (DAAD-15-03), National Programme for Sustainability I (LO1415) and project DFG (MA 5826/2-1). We would like to thank Marek Jakubik, Katerina Svobodova, Sinikka Paulus, Ellen Halaburt and Sally Haddad for technical support.

  11. Upland Trees Contribute to Exchange of Nitrous Oxide (N2O) in Forest Ecosystems

    Science.gov (United States)

    Tian, H.; Thompson, R.; Canadell, J.; Winiwarter, W.; Machacova, K.; Maier, M.; Halmeenmäki, E.; Svobodova, K.; Lang, F.; Pihlatie, M.; Urban, O.

    2017-12-01

    The increase in atmospheric nitrous oxide (N2O) concentration contributes to the acceleration of the greenhouse effect. However, the role of trees in the N2O exchange of forest ecosystems is still an open question. While the soils of temperate and boreal forests were shown to be a natural source of N2O, trees have been so far overlooked in the forest N2O inventories. We determined N2O fluxes in common tree species of boreal and temperate forests: Scots pine (Pinus sylvestris), Norway spruce (Picea abies), downy and silver birch (Betula pubescens, B. pendula), and European beech (Fagus sylvatica). We investigated (1) whether these tree species exchange N2O with the atmosphere under natural field conditions, (2) how the tree N2O fluxes contribute to the forest N2O balance, and (3) whether these fluxes show seasonal dynamics. The studies were performed in a boreal forest (SMEAR II station, Finland; June 2014 - May 2015) and two temperate mountain forests (White Carpathians, Czech Republic; Black Forest, Germany; June and July 2015). Fluxes of N2O in mature tree stems and forest floor were measured using static chamber systems followed by chromatographic and photo-acoustic analyses of N2O concentration changes. Pine, spruce and birch trees were identified as net annual N2O sources. Spruce was found the strongest emitter (0.27 mg ha-1 h-1) amounting thus up to 2.5% of forest floor N2O emissions. All tree species showed a substantial seasonality in stem N2O flux that was related to their physiological activity and climatic variables. In contrast, stems of beech trees growing at soils consuming N2O may act as a substantial sink of N2O from the atmosphere. Consistent N2O consumption by tree stems ranging between -12.1 and -35.2 mg ha-1 h-1 and contributing by up to 3.4% to the forest floor N2O uptake is a novel finding in contrast to current studies presenting trees as N2O emitters. To understand these fluxes, N2O exchange of photoautotrophic organisms associated with

  12. Status and trend of tree growth and mortality rate at the CONECOFOR plots, 1997-2004

    Directory of Open Access Journals (Sweden)

    Gianfranco Fabbio

    2013-11-01

    Full Text Available The circumference of trees in the CONECOFOR permanent monitoring plots (PMPs were measured by three surveys carried out in 1997, 2000 and 2005. Plots were arranged into forest types according to tree species, management system and stand structure: beech (Fagus sylvatica L. and spruce (Picea abies K. high forests, aged coppice forests and transitory crops (deciduous, evergreen oaks and beech. Diameter distribution, basal area, basal area increment, tree mortality rate and in-growth were calculated per layer (dominant, intermediate, dominated within each PMP, to point out relative contributions and changes. A range in relative annual growth was detected both within and between types over the monitored period, but an obvious reduction of annual increment was found in two/thirds of plots over 2000-04 as compared to 1997-99. Current mortality, mostly allocated into the dominated and intermediate layers, can be explained as “regular” due to overstocking and high inter-tree competition in almost all of the observed case-studies. Opposite patterns were found to occur as for stand growth vs. mortality rate between coppice forests and the other types owing to the different dynamics of tree competition in progress. Drought 2003 is the likely large-scale factor determining the reduced annual growth course over the second period.

  13. Late Holocene Decline of Beech Populations in the Central Great Lakes Region: Drought- Induced Vegetation Change in a Humid Region.

    Science.gov (United States)

    Booth, R. K.; Jackson, S. T.; Taylor, M.; Pendall, E.; Sousa, V. A.

    2007-12-01

    A large decline in beech populations ( Fagus grandifolia) has been well-documented from pollen records in southeastern Michigan and Southern Ontario between 1000 and 600 BP. These records reveal that declines in beech pollen were generally associated with increases in oak ( Quercus) and pine ( Pinus). The beech decline probably extended eastward into western Pennsylvania and New York, although beech populations in Upper Michigan remained unaffected or even expanded during this time period. The causes of these forest changes and their spatial patterning is not completely understood, although they have been variously attributed to anthropogenic disturbance, climatic cooling, or drought. Recent paleoclimate evidence from the region indicates that the most severe droughts of the last 2000 years occurred between 1000 and 700 BP. However, direct attribution of drought as a cause of the decline has been problematic because of uncertainties associated with comparison of radiocarbon-dated chronologies. We have conducted tandem investigations of pollen, charcoal, hydroclimate proxies (testate amoebae, humification), and a temperature proxy (d18O of Sphagnum cellulose) from the archives contained in three Sphagnum-dominated peatlands of the region. Two of these peatlands were located within the region of the beech decline (eastern, lower Michigan) and the other was outside the decline region (Upper Michigan). Our results reveal that a series of large droughts, likely the combined result of decreased summer precipitation and warm temperatures, were associated with the beech decline. Large wildfires were also associated with the droughts. Neither droughts nor beech declines were recorded in Upper Michigan. High-resolution analysis of beech pollen and hydroclimate proxies at sites that experienced the droughts reveals complex dynamics at multidecadal timescales between 1000-700 BP, with large fluctuations in beech pollen, available moisture, and charcoal concentrations. Our

  14. Temporal variability of the NPP-GPP ratio at seasonal and interannual time scales in a temperate beech forest

    Directory of Open Access Journals (Sweden)

    M. Campioli

    2011-09-01

    Full Text Available The allocation of carbon (C taken up by the tree canopy for respiration and production of tree organs with different construction and maintenance costs, life span and decomposition rate, crucially affects the residence time of C in forests and their C cycling rate. The carbon-use efficiency, or ratio between net primary production (NPP and gross primary production (GPP, represents a convenient way to analyse the C allocation at the stand level. In this study, we extend the current knowledge on the NPP-GPP ratio in forests by assessing the temporal variability of the NPP-GPP ratio at interannual (for 8 years and seasonal (for 1 year scales for a young temperate beech stand, reporting dynamics for both leaves and woody organs, in particular stems. NPP was determined with biometric methods/litter traps, whereas the GPP was estimated via the eddy covariance micrometeorological technique.

    The interannual variability of the proportion of C allocated to leaf NPP, wood NPP and leaf plus wood NPP (on average 11% yr−1, 29% yr−1 and 39% yr−1, respectively was significant among years with up to 12% yr−1 variation in NPP-GPP ratio. Studies focusing on the comparison of NPP-GPP ratio among forests and models using fixed allocation schemes should take into account the possibility of such relevant interannual variability. Multiple linear regressions indicated that the NPP-GPP ratio of leaves and wood significantly correlated with environmental conditions. Previous year drought and air temperature explained about half of the NPP-GPP variability of leaves and wood, respectively, whereas the NPP-GPP ratio was not decreased by severe drought, with large NPP-GPP ratio on 2003 due mainly to low GPP. During the period between early May and mid June, the majority of GPP was allocated to leaf and stem NPP, whereas these sinks were of little importance later on. Improved estimation of seasonal GPP and of the

  15. De novo transcriptome assembly and analysis of differential gene expression in response to drought in European beech.

    Directory of Open Access Journals (Sweden)

    Markus Müller

    Full Text Available Despite the ecological and economic importance of European beech (Fagus sylvatica L. genomic resources of this species are still limited. This hampers an understanding of the molecular basis of adaptation to stress. Since beech will most likely be threatened by the consequences of climate change, an understanding of adaptive processes to climate change-related drought stress is of major importance. Here, we used RNA-seq to provide the first drought stress-related transcriptome of beech. In a drought stress trial with beech saplings, 50 samples were taken for RNA extraction at five points in time during a soil desiccation experiment. De novo transcriptome assembly and analysis of differential gene expression revealed 44,335 contigs, and 662 differentially expressed genes between the stress and normally watered control group. Gene expression was specific to the different time points, and only five genes were significantly differentially expressed between the stress and control group on all five sampling days. GO term enrichment showed that mostly genes involved in lipid- and homeostasis-related processes were upregulated, whereas genes involved in oxidative stress response were downregulated in the stressed seedlings. This study gives first insights into the genomic drought stress response of European beech, and provides new genetic resources for adaptation research in this species.

  16. Influence of xylem ray integrity and degree of polymerization on bending strength of beech wood decayed by Pleurotus ostreatus and Trametes versicolor

    Science.gov (United States)

    Ehsan Bari; Reza Oladi; Olaf Schmidt; Carol A. Clausen; Katie Ohno; Darrel D. Nicholas; Mehrdad Ghodskhah Daryaei; Maryam Karim

    2015-01-01

    The scope of this research was to evaluate the influence of xylem ray (XR) and degree of polymerization (DP) of holocellulose in Oriental beech wood (Fagus orientalis Lipsky.) on impact bending strength against two white-rot fungi. Beech wood specimens, exposed to Pleurotus ostreatus and Trametes versicolor, were evaluated for...

  17. Tree Species Identity Shapes Earthworm Communities

    Directory of Open Access Journals (Sweden)

    Stephanie Schelfhout

    2017-03-01

    Full Text Available Earthworms are key organisms in forest ecosystems because they incorporate organic material into the soil and affect the activity of other soil organisms. Here, we investigated how tree species affect earthworm communities via litter and soil characteristics. In a 36-year old common garden experiment, replicated six times over Denmark, six tree species were planted in blocks: sycamore maple (Acer pseudoplatanus, beech (Fagus sylvatica, ash (Fraxinus excelsior, Norway spruce (Picea abies, pedunculate oak (Quercus robur and lime (Tilia cordata. We studied the chemical characteristics of soil and foliar litter, and determined the forest floor turnover rate and the density and biomass of the earthworm species occurring in the stands. Tree species significantly affected earthworm communities via leaf litter and/or soil characteristics. Anecic earthworms were abundant under Fraxinus, Acer and Tilia, which is related to calcium-rich litter and low soil acidification. Epigeic earthworms were indifferent to calcium content in leaf litter and were shown to be mainly related to soil moisture content and litter C:P ratios. Almost no earthworms were found in Picea stands, likely because of the combined effects of recalcitrant litter, low pH and low soil moisture content.

  18. Flowering Trees

    Indian Academy of Sciences (India)

    Flowering Trees. Acrocarpus fraxinifolius Wight & Arn. (PINK CEDAR, AUSTRALIAN ASH) of. Caesalpiniaceae is a lofty unarmed deciduous native tree that attains a height of 30–60m with buttresses. Bark is thin and light grey. Leaves are compound and bright red when young. Flowers in dense, erect, axillary racemes.

  19. Flowering Trees

    Indian Academy of Sciences (India)

    Brachichiton acerifolius F. Muell., commonly called as the Illawara flame tree is a member of Malvaceae family and is native to sub-tropical parts of Australia. Due to its spectacular flowers and tolerance to wide range of climates, it's now cultivated all over the world for its beauty. The tree produces flowers during the.

  20. Flowering Trees

    Indian Academy of Sciences (India)

    Cassia siamia Lamk. (Siamese tree senna) of Caesalpiniaceae is a small or medium size handsome tree. Leaves are alternate, pinnately compound and glandular, upto 18 cm long with 8–12 pairs of leaflets. Inflorescence is axillary or terminal and branched. Flowering lasts for a long period from March to February.

  1. Flowering Trees

    Indian Academy of Sciences (India)

    Srimath

    Grevillea robusta A. Cunn. ex R. Br. (Sil- ver Oak) of Proteaceae is a daintily lacy ornamental tree while young and growing into a mighty tree (45 m). Young shoots are silvery grey and the leaves are fern- like. Flowers are golden-yellow in one- sided racemes (10 cm). Fruit is a boat- shaped, woody follicle.

  2. Flowering Trees

    Indian Academy of Sciences (India)

    Baccaurea courtallensis Muell.-Arg. of Euphorbiaceae is an evergreen tree that is very attractive when in flower. Leaves are alternate. Male and female flowers are borne on separate trees. Inflorescences bearing several flowers arise in tufts on tubercles on the stem. Fruits are crimson red in colour. Seeds are covered.

  3. Some clastic rocks as parent rocks in beech forests of Brezovica - Južni Kučaj

    Directory of Open Access Journals (Sweden)

    Joksimović Vesna

    2003-01-01

    Full Text Available On the large forest areas, where the measures of soil quality improvement are absent or rarely undertaken, the rocks are the sources of a great number of elements in plant nutrition and one of the factors affecting the contents of some elements in plants. The aim of the study is to determine the differences in the contents of Cu, Zn, Mn, Ni, Fe, Cd, Co, Pb and Cr in the beech leaves developed in the same climate conditions, on morphologically similar terrains, composed of different types of sedimentary rocks. This paper presents the study results of the contents of the above elements in argillites, sandstones (grauwackes and microconglomerates occurring as the parent rocks in high beech forests in the region of GJ Bogovina (Brezovica Južni Kučaj and in the leaves of beech developed on these rocks.

  4. Contributions to the phytocoenologic study in pure european beech stand forests in Codru-Moma Mountains (North-Western Romania

    Directory of Open Access Journals (Sweden)

    Călin-Gheorghe PĂŞCUŢ

    2010-05-01

    Full Text Available In the present work we present a phytocoenologic study on the associations found in pure European beech stand forests in Codru-Moma Mountains namely: Festuco drymejae-Fagetum Morariu et al. 1968, Luzulo albidae-Fagetum sylvaticae Zólyomi 1955.Characterization of the associations we studied and presentation of the tables have been made considering the selection of the most representative relevées of pure European beech forests belonging to Codru-Moma Mountains.The phytocoenoses of pure forest stands of European beech forests belonging to the two associations were analyzed in terms of floristic composition, life forms spectrum, spectrum chart of the floral elements and ecological indices.

  5. Forest vegetation in western Romania in relation to climate variables: Does community composition reflect modelled tree species distribution?

    Directory of Open Access Journals (Sweden)

    S. Heinrichs

    2016-12-01

    Full Text Available European beech (Fagus sylvatica L. is the prevailing tree species of mesic forests in Central Europe. Increasing summer temperatures and decreasing precipitation, as climate change scenarios predict, may, however, negatively influence beech growth and induce a shift to more thermophilous forest communities. Temperatures as expected in the future for western Central Europe are currently found in parts of western Romania. In light of this climate analogy we investigated forest vegetation as an indicator for future vegetation changes in five regions of western Romania representing a climatic gradient. We related species composition to climate variables and examined if tree and understorey species composition respond similarly to the climatic gradient. We further analysed if tree species occurrences correspond with their modelled distance to the rear niche edge. We found evidence for climatic effects on vegetation composition among regions as well as within deciduous and pine forests, respectively. This underlines that vegetation composition is a useful indicator for environmental change. Tree and understorey species compositions were closely linked showing that community-based characterization of forest stands can provide additional information on tree species suitability along environmental gradients. Both, vegetation composition and a climatic marginality index demonstrate the rear niche edge occurrence of beech in the studied sites of Romania and can predict the site suitability for different tree species. While vegetation surveys indicate Quercus petraea to be associated to moderately mesic forests, the marginality index suggested an inner niche position of sessile oak along the climatic gradient. Phytosociological relevés that differentiate between subspecies (or microspecies of sessile oak with differing habitat requirements should be considered to complement national forest inventories and species distribution maps when modelling rear

  6. Soil carbon accumulation and nitrogen retention traits of four tree species grown in common gardens

    DEFF Research Database (Denmark)

    Gurmesa, Geshere Abdisa; Schmidt, Inger Kappel; Gundersen, Per

    2013-01-01

    explored. Effects of four tree species on soil C and N stocks and soil water nitrate concentration below the root zone were evaluated in a common garden design replicated at eight sites in Denmark. The tree species were beech (Fagus sylvatica L.), oak (Quercus robur L.), larch (Larix leptolepis Kaempf......Tree species effects on soil carbon (C) accumulation are uncertain, especially with respect to the mineral soil C, and the consistency of such effects across soil types is not known. The interaction between C accumulation and nitrogen (N) retention among common tree species has also been little......), and Norway spruce (Picea abies (L) Karst.). After four decades, there were significant differences in forest floor C stocks among all four species, and C stocks increased consistently in the order oak soil texture gradient of the sites. Forest floor N stocks only...

  7. Leaf area index from litter collection: impact of specific leaf area variability within a beech stand

    International Nuclear Information System (INIS)

    Bouriaud, O.; Soudani, K.; Breda, N.

    2003-01-01

    Litter fall collection is a direct method widely used to estimate leaf area index (LAI) in broad-leaved forest stands. Indirect measurements using radiation transmittance and gap fraction theory are often compared and calibrated against litter fall, which is considered as a reference method, but few studies address the question of litter specific leaf area (SLA) measurement and variability. SLA (leaf area per unit of dry weight, m 2 ·g -1 ) is used to convert dry leaf litter biomass (g .m - 2) into leaf area per ground unit area (m 2 ·m -2 ). We paid special attention to this parameter in two young beech stands (dense and thinned) in northeastern France. The variability of both canopy (closure, LAI) and site conditions (soil properties, vegetation) was investigated as potential contributing factors to beech SLA variability. A systematic description of soil and floristic composition was performed and three types of soil were identified. Ellenberg's indicator values were averaged for each plot to assess nitrogen soil content. SLA of beech litter was measured three times during the fall in 23 plots in the stands (40 ha). Litter was collected bimonthly in square-shaped traps (0.5 m 2 ) and dried. Before drying, 30 leaves per plot and for each date were sampled, and leaf length, width, and area were measured with the help of a LI-COR areameter. SLA was calculated as the ratio of cumulated leaf area to total dry weight of the 30 leaves. Leaves characteristics per plot were averaged for the three dates of litter collection. Plant area index (PAI), estimated using the LAI-2000 plant canopy analyser and considering only the upper three rings, ranged from 2.9 to 8.1. Specific leaf area of beech litter was also highly different from one plot to the other, ranging from 150 to 320 cm 2 ·g -1 . Nevertheless, no relationship was found between SLA and stand canopy closure or PAI On the contrary, a significant relationship between SLA and soil properties was observed. Both SLA

  8. Heavy metal concentrations of the moss Mnium hornum in beech stands of the Westphalian Bight

    International Nuclear Information System (INIS)

    Clement, M.; Werner, W.

    1989-01-01

    Samples of Mnium hornum (Hedw.), collected in beech forests of the Westphalian Bight and its adjoining fringe mountains (Teutoburger Wald, Eggegebirge), were analysed for Pb, Zn and Cd. It could be shown that heavy metal contents of Mnium hornum decrease with increasing distance to the Ruhr area, the main location of heavy metal emitting coal and steel industry in North Rhine-Westphalia. On the other hand the contents increase with altitude in the Teutoburger Wald and the Eggegebirge, which are the first north-eastern and eastern lying barriers for the main southwest and west winds from the Ruhr area. (orig.)

  9. Identification of stress biomarkers for drought and increased soil temperature in seedlings of European beech ( Fagus sylvatica )

    Energy Technology Data Exchange (ETDEWEB)

    Popović, Milica [Department of Biochemistry, Faculty of Chemistry, University of Belgrade, Belgrade, Serbia.; Laboratory for Environmental and Life Sciences, University of Nova Gorica, Glavni Trg 9 – SI-5261, Vipava, Slovenia.; Gregori, Marco [Laboratory for Environmental and Life Sciences, University of Nova Gorica, Glavni Trg 9 – SI-5261, Vipava, Slovenia.; Dipartimento di Scienze Mediche Chirurgiche e della Salute Trieste, Universita degli Studi di Trieste, Friuli-Venezia Giulia, Italy.; Vodnik, Dominik [Biotechnical Faculty, Department of Agronomy, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia.; Ferlan, Mitja [Slovenian Forestry Institute, Večna pot 2, SI-1000 Ljubljana, Slovenia.; Mrak, Tanja [Slovenian Forestry Institute, Večna pot 2, SI-1000 Ljubljana, Slovenia.; Štraus, Ines [Slovenian Forestry Institute, Večna pot 2, SI-1000 Ljubljana, Slovenia.; McDowell, Nathan G. [Slovenian Forestry Institute, Večna pot 2, SI-1000 Ljubljana, Slovenia.; Pacific Northwest National Laboratory, Richland, WA 99354, USA.; Kraigher, Hojka [Slovenian Forestry Institute, Večna pot 2, SI-1000 Ljubljana, Slovenia.; de Marco, Ario [Laboratory for Environmental and Life Sciences, University of Nova Gorica, Glavni Trg 9 – SI-5261, Vipava, Slovenia.

    2017-11-01

    Drought is an environmental stress that impacts plant productivity. Projections show both an increase in intense rain events and a reduction in the number of rain days, conditions that leads to increased risk of drought. Consequently, the identification of molecular biomarkers suitable for evaluating the impact of water deprivation conditions on forest plant seedlings is of significant value for monitoring purposes and forest management. In this study, we evaluated a biochemical methodology for the assessment of drought stress coupled with variable soil temperature in European beech (Fagus sylvatica L.) seedlings by analyzing a set of metabolites and enzymes involved in free radical scavenging and cell wall synthesis. The results indicate that the specific activities and isoform profile of superoxide dismutases and glutathione peroxidases together with the variation of phenolic compounds enable discrimination between seedlings with different degrees of photosynthetic activity. This approach represents a promising platform for the assessment of drought stress in forest trees and could serve for enhancing selection and breeding practices, allowing for plants that are more tolerant of abiotic stress.

  10. Detecting short spatial scale local adaptation and epistatic selection in climate-related candidate genes in European beech (Fagus sylvatica) populations.

    Science.gov (United States)

    Csilléry, Katalin; Lalagüe, Hadrien; Vendramin, Giovanni G; González-Martínez, Santiago C; Fady, Bruno; Oddou-Muratorio, Sylvie

    2014-10-01

    Detecting signatures of selection in tree populations threatened by climate change is currently a major research priority. Here, we investigated the signature of local adaptation over a short spatial scale using 96 European beech (Fagus sylvatica L.) individuals originating from two pairs of populations on the northern and southern slopes of Mont Ventoux (south-eastern France). We performed both single and multilocus analysis of selection based on 53 climate-related candidate genes containing 546 SNPs. FST outlier methods at the SNP level revealed a weak signal of selection, with three marginally significant outliers in the northern populations. At the gene level, considering haplotypes as alleles, two additional marginally significant outliers were detected, one on each slope. To account for the uncertainty of haplotype inference, we averaged the Bayes factors over many possible phase reconstructions. Epistatic selection offers a realistic multilocus model of selection in natural populations. Here, we used a test suggested by Ohta based on the decomposition of the variance of linkage disequilibrium. Overall populations, 0.23% of the SNP pairs (haplotypes) showed evidence of epistatic selection, with nearly 80% of them being within genes. One of the between gene epistatic selection signals arose between an FST outlier and a nonsynonymous mutation in a drought response gene. Additionally, we identified haplotypes containing selectively advantageous allele combinations which were unique to high or low elevations and northern or southern populations. Several haplotypes contained nonsynonymous mutations situated in genes with known functional importance for adaptation to climatic factors. © 2014 John Wiley & Sons Ltd.

  11. 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.

  12. Environment vs. Plant Ontogeny: Arthropod Herbivory Patterns on European Beech Leaves along the Vertical Gradient of Temperate Forests in Central Germany

    Directory of Open Access Journals (Sweden)

    Stephanie Stiegel

    2018-01-01

    Full Text Available Environmental and leaf trait effects on herbivory are supposed to vary among different feeding guilds. Herbivores also show variability in their preferences for plant ontogenetic stages. Along the vertical forest gradient, environmental conditions change, and trees represent juvenile and adult individuals in the understorey and canopy, respectively. This study was conducted in ten forests sites in Central Germany for the enrichment of canopy research in temperate forests. Arthropod herbivory of different feeding traces was surveyed on leaves of Fagus sylvatica Linnaeus (European beech; Fagaceae in three strata. Effects of microclimate, leaf traits, and plant ontogenetic stage were analyzed as determining parameters for herbivory. The highest herbivory was caused by exophagous feeding traces. Herbivore attack levels varied along the vertical forest gradient for most feeding traces with distinct patterns. If differences of herbivory levels were present, they only occurred between juvenile and adult F. sylvatica individuals, but not between the lower and upper canopy. In contrast, differences of microclimate and important leaf traits were present between the lower and upper canopy. In conclusion, the plant ontogenetic stage had a stronger effect on herbivory than microclimate or leaf traits along the vertical forest gradient.

  13. Flowering Trees

    Indian Academy of Sciences (India)

    Srimath

    shaped corolla. Fruit is large, ellipsoidal, green with a hard and smooth shell containing numerous flattened seeds, which are embedded in fleshy pulp. Calabash tree is commonly grown in the tropical gardens of the world as a botanical oddity.

  14. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  15. Seasonal variations of the amount of carbon allocated to respiration after in situ 13CO2 pulse labelling of trees (Invited)

    Science.gov (United States)

    Epron, D.; Dannoura, M.; Ngao, J.; Plain, C.; Berveller, D.; Chipeaux, C.; Gerant, D.; Bosc, A.; Maillard, P.; Loustau, D.; Damesin, C.; Cats Project (Anr-07-Blan-0109)

    2010-12-01

    Soil and trunk respiration are the major sources of carbon from forest ecosystems to the atmosphere and they account for a large fraction of total ecosystem respiration. The amount of photosynthate allocated to respiration affects the growth of the tree and the potential for carbon sequestration of forest ecosystems. This study, aiming at understanding patterns of carbon allocation to respiration among species and seasons, consisted in pure 13CO2 labelling of the entire crown of three different tree species (beech, oak and pine) at distinct phenological stages between Sept 2008 and Feb 2010. 13C was then tracked for several weeks in soil and trunk CO2 efflux at high temporal resolution using tuneable diode laser absorption spectrometry (Plain et al. 2009). Recovery of 13C in trunk and soil CO2 efflux was observed a few couple of hours after the beginning of the labelling in oak and beech. There is a rapid transfer of 13C belowground with a maximum occurring within 2 to 4 days after labelling. Label was recovered at the same time in the respiration and in the biomass of both fine roots and microbes. Maximum recovery occurred earlier in beech and oak, while it happened later in Pine. Indeed, the velocity of phloem transport, calculated as the difference of time lags in 13C recovery in trunk respiration at different height, was around 0.10-0.2m/h in pine and around 0.2-1.2 m/h in oak and beech, reflecting difference in phloem anatomy between angiosperm and gymnosperm. The cumulated amount of label recovered in soil CO2 efflux 20 days after labelling varied among the seasons in all species, from 1 to 16% in beech, 2 to 11% in oak and 1 to 11% in pine. For all species, allocation to soil respiration was greater in early summer compared to spring, late summer and autumn. A compartmental analysis is further conducted to characterise functional pools of labelled substrates and storage compounds that contribute to both trunk and soil respiration. [Plain C, Gérant D

  16. Preparation, characterization and phenol adsorption capacity of activated carbons from African beech wood sawdust

    Directory of Open Access Journals (Sweden)

    N.T. Abdel-Ghani

    2016-05-01

    Full Text Available In the present study, different activated carbons were prepared from carbonized African beech wood sawdust by potassium hydroxide activation. The activated carbons were characterized by brunauer–emmett–teller, scanning electron microscope, fourier transform infrared spectroscopy, and thermogravimetric analyzer. The phenol adsorption capacity of the prepared carbons was evaluated. The different factors affecting phenol’s removal were studied including: contact time, solution pH and initial phenol concentration. The optimum phenol removal was obtained after a contact time of 300 min. and at an initial phenol solution pH 7. The maximum removal percentages were determined at 5mg/l initial phenol concentration as 79, 93, 94 and 98% for AC0, AC1, AC2 and AC3; respectively. The adsorption of phenol on African beech sawdust activated carbons was found to follow the Lagergren first order kinetics and the intraparticle diffusion mechanism gave a good fit to the experimental data. The isothermal models applied fitted the experimental data in the order: Langmuir> Dubinin–Radushkevich> Freundlich and Temkin.

  17. Heat capacity and phonon mean free path in the biocarbon matrix of beech

    Science.gov (United States)

    Parfen'eva, L. S.; Orlova, T. S.; Smirnov, B. I.; Smirnov, I. A.; Misiorek, H.; Wlosewicz, D.; Jezowski, A.

    2011-08-01

    The heat capacity at constant pressure C p of the biocarbon matrix prepared at a beech wood carbonization temperature of 1000°C has been measured in the temperature range 80-300 K. It has been shown that, in the temperature range 90-180 K, the heat capacity is C ˜ T 0.8 and, at T = 190-300 K, it is C p ˜ T 1.2. The phonon mean free path l( T) in the biocarbon matrix has been calculated using the obtained dependences C p ( T), our previous results on the phonon thermal conductivity of the carbon framework of this biocarbon matrix, and data available in the literature on the sound velocity in the matrix. It has been demonstrated that, in the temperature range 200-300 K, the mean value of l is ˜ 15 Å, which is close to the sizes of nanocrystallites ("carbon fragments") of ˜ 12Å, obtained earlier from X-ray diffraction data for the carbon matrix under consideration. These nanocrystallites participate in the formation of the carbon framework of the beech wood biocarbon matrix.

  18. Plant biodiversity of beech forests in central-northern Italy: a methodological approach for conservation purposes

    Directory of Open Access Journals (Sweden)

    Marcantonio M

    2012-07-01

    Full Text Available Forests are reckoned essentials as biodiversity reservoirs and carbon sinks. Current threats to forest ecosystems (e.g., climate changes, habitat loss and fragmentation, management changes call for monitoring their biodiversity and preserving their ecological functions. In this study, we characterized plants diversity of five beech forests located in central and north Apennines mountain chain, using results by a probabilistic sampling. In order to achieve our goals, we have considered species richness and abundance, taxonomic distinctness and species composition, using both old and new analytical approaches. Results have shown how: (1 the forest type dominated by Fagus sylvatica is characterized by high complexity, with marked compositional, structural and biodiversity differences; (2 beech forests of Pigelleto di Piancastagnaio and Valle della Corte show the highest plants diversity values. The ecological characteristics of these areas, which sustain high diversity values, are unique and of great conservation interest; (3 the use of species richness as the only diversity measure have not allowed an efficient differentiation between studied areas. Indeed, the use of different indexes and analytical methods is required to detect multiple characteristics of biological diversity, as well as to carry out efficient biodiversity surveys aimed to develop optimal conservation strategies. In the future, we plan to apply the sampling methodology and the analytical approach used in this paper to characterize plants diversity of similar forest types.

  19. Investigating the European beech (Fagus sylvatica L.) leaf characteristics along the vertical canopy profile: leaf structure, photosynthetic capacity, light energy dissipation and photoprotection mechanisms.

    Science.gov (United States)

    Scartazza, Andrea; Di Baccio, Daniela; Bertolotto, Pierangelo; Gavrichkova, Olga; Matteucci, Giorgio

    2016-09-01

    Forest functionality and productivity are directly related to canopy light interception and can be affected by potential damage from high irradiance. However, the mechanisms by which leaves adapt to the variable light environments along the multilayer canopy profile are still poorly known. We explored the leaf morphophysiological and metabolic responses to the natural light gradient in a pure European beech (Fagus sylvatica L.) forest at three different canopy heights (top, middle and bottom). Structural adjustment through light-dependent modifications in leaf mass per area was the reason for most of the variations in photosynthetic capacity. The different leaf morphology along the canopy influenced nitrogen (N) partitioning, water- and photosynthetic N-use efficiency, chlorophyll (Chl) fluorescence and quali-quantitative contents of photosynthetic pigments. The Chl a to Chl b ratio and the pool of xanthophyll-cycle pigments (VAZ) increased at the highest irradiance, as well as lutein and β-carotene. The total pool of ascorbate and phenols was higher in leaves of the top and middle canopy layers when compared with the bottom layer, where the ascorbate peroxidase was relatively more activated. The non-photochemical quenching was strongly and positively related to the VAZ/(Chl a + b) ratio, while Chl a/Chl b was related to the photochemical efficiency of photosystem II. Along the multilayer canopy profile, the high energy dissipation capacity of leaves was correlated to an elevated redox potential of antioxidants. The middle layer gave the most relevant contribution to leaf area index and carboxylation capacity of the canopy. In conclusion, a complex interplay among structural, physiological and biochemical traits drives the dynamic leaf acclimation to the natural gradients of variable light environments along the tree canopy profile. The relevant differences observed in leaf traits within the canopy positions of the beech forest should be considered for

  20. Tree Age Effects on Fine Root Biomass and Morphology over Chronosequences of Fagus sylvatica, Quercus robur and Alnus glutinosa Stands.

    Science.gov (United States)

    Jagodzinski, Andrzej M; Ziółkowski, Jędrzej; Warnkowska, Aleksandra; Prais, Hubert

    2016-01-01

    There are few data on fine root biomass and morphology change in relation to stand age. Based on chronosequences for beech (9-140 years old), oak (11-140 years) and alder (4-76 years old) we aimed to examine how stand age affects fine root biomass and morphology. Soil cores from depths of 0-15 cm and 16-30 cm were used for the study. In contrast to previously published studies that suggested that maximum fine root biomass is reached at the canopy closure stage of stand development, we found almost linear increases of fine root biomass over stand age within the chronosequences. We did not observe any fine root biomass peak in the canopy closure stage. However, we found statistically significant increases of mean fine root biomass for the average individual tree in each chronosequence. Mean fine root biomass (0-30 cm) differed significantly among tree species chronosequences studied and was 4.32 Mg ha(-1), 3.71 Mg ha(-1) and 1.53 Mg ha(-1), for beech, oak and alder stands, respectively. The highest fine root length, surface area, volume and number of fine root tips (0-30 cm soil depth), expressed on a stand area basis, occurred in beech stands, with medium values for oak stands and the lowest for alder stands. In the alder chronosequence all these values increased with stand age, in the beech chronosequence they decreased and in the oak chronosequence they increased until ca. 50 year old stands and then reached steady-state. Our study has proved statistically significant negative relationships between stand age and specific root length (SRL) in 0-30 cm soil depth for beech and oak chronosequences. Mean SRLs for each chronosequence were not significantly different among species for either soil depth studied. The results of this study indicate high fine root plasticity. Although only limited datasets are currently available, these data have provided valuable insight into fine root biomass and morphology of beech, oak and alder stands.

  1. Removal of non benzidine direct red dye from aqueous solution by using natural sorbents: Beech and silver fir

    Czech Academy of Sciences Publication Activity Database

    Muntean, S.G.; Todea, A.; Bakardjieva, Snejana; Bologa, C.

    2017-01-01

    Roč. 66, MAR (2017), s. 235-250 ISSN 1944-3994 Institutional support: RVO:61388980 Keywords : Adsorption * Beech * Direct red * Kinetics * Silver fir Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 1.631, year: 2016

  2. The formation of a ligno-suberised layer and necrophylactic periderm in beech bark (Fagus sylvatica L.)

    Science.gov (United States)

    Primoz Oven; Niko Torelli; Walter C. Shortle; Martin Zupancic

    1999-01-01

    Beech (Fagus sylvatica L.) bark was wounded in early April of 1993 and tissue changes followed on days 7, 14, 21, 28, 35, 42, 49, 56, 84, 112, and 140. In 7 days, tissue at the wound surface became necrotic and discoloured. In 14 days the walls of the parenchyma cells immediately underneath the necrotic tissue became thickened and after 21 days...

  3. Mechanical properties and chemical composition of beech wood exposed for 30 and 120 days to white-rot fungi

    Science.gov (United States)

    Ehsan Bari; Hamid Reza Taghiyari; Behbood Mohebby; Carol A. Clausen; Olaf Schmidt; Mohammad Ali Tajick Ghanbary; Mohammad Javad Vaseghi

    2015-01-01

    The effects of exposing specimens of Oriental beech [Fagus sylvatica subsp. orientalis (Lipsky) Greuter and Burdet] to the white-rot fungi Pleurotus ostreatus (Jacq.: Fr.) Kummer and Trametes versicolor (L.: Fr.) Pilát strain 325 have been studied concerning the mechanical properties and...

  4. Effect of particle size on the composition of lignin derived oligomers obtained by fast pyrolysis of beech wood

    NARCIS (Netherlands)

    Zhou, Shuai; Garcia-Perez, Manuel; Pecha, Brennan; McDonald, Armando G.; Westerhof, Roel Johannes Maria

    2014-01-01

    The effect of particle size on the yield and composition of lignin derived oligomers (also known as pyrolytic lignin (PL)) was studied in a fluidized bed reactor. Milled beech wood particles of sizes between 0.3 and 0.55 and cylinders of 3–14 mm were pyrolyzed at 500 °C. The lignin oligomers were

  5. 77 FR 31642 - Hawker Beech Craft Defense Company, LLC, Also Known As Hawker Beechcraft Corporation, Also Known...

    Science.gov (United States)

    2012-05-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Employment and Training Administration Hawker Beech Craft Defense Company, LLC, Also Known As Hawker Beechcraft Corporation, Also Known As Hawker Beechcraft International SVC, Also Known As Rapid Surplus Parts...

  6. Local-scale topoclimate effects on treeline elevations: a country-wide investigation of New Zealand’s southern beech treelines

    Directory of Open Access Journals (Sweden)

    Bradley S. Case

    2015-10-01

    Full Text Available Although treeline elevations are limited globally by growing season temperature, at regional scales treelines frequently deviate below their climatic limit. The cause of these deviations relate to a host of climatic, disturbance, and geomorphic factors that operate at multiple scales. The ability to disentangle the relative effects of these factors is currently hampered by the lack of reliable topoclimatic data, which describe how regional climatic characteristics are modified by topographic effects in mountain areas. In this study we present an analysis of the combined effects of local- and regional-scale factors on southern beech treeline elevation variability at 28 study areas across New Zealand. We apply a mesoscale atmospheric model to generate local-scale (200 m meteorological data at these treelines and, from these data, we derive a set of topoclimatic indices that reflect possible detrimental and ameliorative influences on tree physiological functioning. Principal components analysis of meteorological data revealed geographic structure in how study areas were situated in multivariate space along gradients of topoclimate. Random forest and conditional inference tree modelling enabled us to tease apart the relative effects of 17 explanatory factors on local-scale treeline elevation variability. Overall, modelling explained about 50% of the variation in treeline elevation variability across the 28 study areas, with local landform and topoclimatic effects generally outweighing those from regional-scale factors across the 28 study areas. Further, the nature of the relationships between treeline elevation variability and the explanatory variables were complex, frequently non-linear, and consistent with the treeline literature. To our knowledge, this is the first study where model-generated meteorological data, and derived topoclimatic indices, have been developed and applied to explain treeline variation. Our results demonstrate the potential

  7. Tree Species Classification By Multiseasonal High Resolution Satellite Data

    Science.gov (United States)

    Elatawneh, Alata; Wallner, Adelheid; Straub, Christoph; Schneider, Thomas; Knoke, Thomas

    2013-12-01

    Accurate forest tree species mapping is a fundamental issue for sustainable forest management and planning. Forest tree species mapping with the means of remote sensing data is still a topic to be investigated. The Bavaria state institute of forestry is investigating the potential of using digital aerial images for forest management purposes. However, using aerial images is still cost- and time-consuming, in addition to their acquisition restrictions. The new space-born sensor generations such as, RapidEye, with a very high temporal resolution, offering multiseasonal data have the potential to improve the forest tree species mapping. In this study, we investigated the potential of multiseasonal RapidEye data for mapping tree species in a Mid European forest in Southern Germany. The RapidEye data of level A3 were collected on ten different dates in the years 2009, 2010 and 2011. For data analysis, a model was developed, which combines the Spectral Angle Mapper technique with a 10-fold- cross-validation. The analysis succeeded to differentiate four tree species; Norway spruce (Picea abies L.), Silver Fir (Abies alba Mill.), European beech (Fagus sylvatica) and Maple (Acer pseudoplatanus). The model success was evaluated using digital aerial images acquired in the year 2009 and inventory point records from 2008/09 inventory. Model results of the multiseasonal RapidEye data analysis achieved an overall accuracy of 76%. However, the success of the model was evaluated only for all the identified species and not for the individual.

  8. Testing the applicability of BIOME-BGC to simulate beech gross primary production in Europe using a new continental weather dataset

    DEFF Research Database (Denmark)

    Chiesi, Marta; Chirici, Gherardo; Marchetti, Marco

    2016-01-01

    A daily 1-km Pan-European weather dataset can drive the BIOME-BGC model for the estimation of current and future beech gross primary production (GPP). Annual beech GPP is affected primarily by spring temperature and more irregularly by summer water stress.The spread of beech forests in Europe...... forest ecosystems having different climatic conditions where the eddy covariance technique is used to measure water and carbon fluxes. The experiment is in three main steps. First, the accuracy of BIOME-BGC GPP simulations is assessed through comparison with flux observations. Second, the influence...

  9. Chemical and morphological characteristics of key tree species of the Carpathian Mountains

    International Nuclear Information System (INIS)

    Mankovska, Blanka; Godzik, Barbara; Badea, Ovidiu; Shparyk, Yuri; Moravcik, Pavel

    2004-01-01

    Concentrations of Al, B, Ca, Cu, Fe, K, Mg, Mn, N, Na, P, S and Zn in the foliage of white fir (Abies alba), Norway spruce (Picea abies) and common beech (Fagus sylvatica) from 25 sites of the Carpathian Mts. forests (Czech Republic, Poland, Romania, Slovakia and Ukraine) are discussed in a context of their limit values. S/N ratio was different from optimum in 90% of localities when compared with the European limit values. Likewise we found increase of Fe and Cu concentrations compared with their background levels in 100% of locations. Mn concentrations were increased in 76% of localities. Mn mobilization values indicate the disturbance of physiological balance leading to the change of the ratio with Fe. SEM-investigation of foliage waxes from 25 sites in the Carpathian Mts. showed, that there is a statistically significant difference in mean wax quality. Epistomatal waxes were damaged as indicated by increased development of net and amorphous waxes. The most damaged stomata in spruce needles were from Yablunitsa, Synevir and Brenna; in fir needles from Stoliky, and in beech leaves from Mala Fatra, Morske Oko and Beregomet. Spruce needles in the Carpathian Mts. had more damaged stomata than fir needles and beech leaves. Spruce seems to be the most sensitive tree species to environmental stresses including air pollution in forests of the Carpathian Mountains. Foliage surfaces of three forest tree species contained Al, Si, Ca, Fe, Mg, K, Cl, Mn, Na, Ni and Ti in all studied localities. Presence of nutrition elements (Ca, Fe, Mg, K and Mn) on foliage surface hinders opening and closing stomata and it is not physiologically usable for tree species. - Chemical composition of foliage and structure of epicuticular waxes indicated phytotoxic effects of air pollution in many forest sites of the Carpathian Mountains

  10. Chemical and morphological characteristics of key tree species of the Carpathian Mountains

    Energy Technology Data Exchange (ETDEWEB)

    Mankovska, Blanka; Godzik, Barbara; Badea, Ovidiu; Shparyk, Yuri; Moravcik, Pavel

    2004-07-01

    Concentrations of Al, B, Ca, Cu, Fe, K, Mg, Mn, N, Na, P, S and Zn in the foliage of white fir (Abies alba), Norway spruce (Picea abies) and common beech (Fagus sylvatica) from 25 sites of the Carpathian Mts. forests (Czech Republic, Poland, Romania, Slovakia and Ukraine) are discussed in a context of their limit values. S/N ratio was different from optimum in 90% of localities when compared with the European limit values. Likewise we found increase of Fe and Cu concentrations compared with their background levels in 100% of locations. Mn concentrations were increased in 76% of localities. Mn mobilization values indicate the disturbance of physiological balance leading to the change of the ratio with Fe. SEM-investigation of foliage waxes from 25 sites in the Carpathian Mts. showed, that there is a statistically significant difference in mean wax quality. Epistomatal waxes were damaged as indicated by increased development of net and amorphous waxes. The most damaged stomata in spruce needles were from Yablunitsa, Synevir and Brenna; in fir needles from Stoliky, and in beech leaves from Mala Fatra, Morske Oko and Beregomet. Spruce needles in the Carpathian Mts. had more damaged stomata than fir needles and beech leaves. Spruce seems to be the most sensitive tree species to environmental stresses including air pollution in forests of the Carpathian Mountains. Foliage surfaces of three forest tree species contained Al, Si, Ca, Fe, Mg, K, Cl, Mn, Na, Ni and Ti in all studied localities. Presence of nutrition elements (Ca, Fe, Mg, K and Mn) on foliage surface hinders opening and closing stomata and it is not physiologically usable for tree species. - Chemical composition of foliage and structure of epicuticular waxes indicated phytotoxic effects of air pollution in many forest sites of the Carpathian Mountains.

  11. Nonlinear mixed effect models for predicting relationships between total height and diameter of oriental beech trees in Kestel, Turkey

    Directory of Open Access Journals (Sweden)

    Ilker Ercanli

    2015-01-01

    Full Text Available Modelos estadísticos no lineales de efectos mixtos se utilizaron para predecir las relaciones entre la altura total y el diámetro a la altura del pecho (DAP en rodales de árboles de haya oriental (Fagus orientalis Lipsky en Kestel, Bursa, al noroeste de Turquía. Un total de 124 parcelas de muestreo se seleccionaron para representar la calidad de sitio, edad y densidad de rodal. Nueve modelos no lineales generalizados de altura-diámetro se ajustaron y evaluaron con base en el criterio de información de Akaike, el criterio de información bayesiana de Schwarz, la raíz del cuadrado medio del error (RMSE por sus siglas en inglés, el sesgo absoluto y el coeficiente de determinación ajustado (R2adj. El modelo no lineal de Schnute se seleccionó como el mejor modelo predictivo. El modelo de altura-diámetro basado en el enfoque del modelo no lineal de efectos mixtos representó 90.6 % de la varianza total en las relaciones de altura-diámetro y los valores de RMSE de 1.48 m. Varios escenarios que difieren en el diseño de muestreo y el tamaño de los árboles submuestra, seleccionados del conjunto de datos de validación, revelaron que cuatro árboles submuestra seleccionados al azar produjeron los mejores resultados predictivos (reducción de 43.3 % de la suma de errores cuadrados, 98.4 % del sesgo absoluto y 36.9 % de la RMSE en relación con las predicciones de los efectos fijos.

  12. Production of high concentrated cellulosic ethanol by acetone/water oxidized pretreated beech wood.

    Science.gov (United States)

    Katsimpouras, Constantinos; Kalogiannis, Konstantinos G; Kalogianni, Aggeliki; Lappas, Angelos A; Topakas, Evangelos

    2017-01-01

    Lignocellulosic biomass is an abundant and inexpensive resource for biofuel production. Alongside its biotechnological conversion, pretreatment is essential to enable efficient enzymatic hydrolysis by making cellulose susceptible to cellulases. Wet oxidation of biomass, such as acetone/water oxidation, that employs hot acetone, water, and oxygen, has been found to be an attractive pretreatment method for removing lignin while producing less degradation products. The remaining enriched cellulose fraction has the potential to be utilized under high gravity enzymatic saccharification and fermentation processes for the cost-competing production of bioethanol. Beech wood residual biomass was pretreated following an acetone/water oxidation process aiming at the production of high concentration of cellulosic ethanol. The effect of pressure, reaction time, temperature, and acetone-to-water ratio on the final composition of the pretreated samples was studied for the efficient utilization of the lignocellulosic feedstock. The optimal conditions were acetone/water ratio 1:1, 40 atm initial pressure of 40 vol% O 2 gas, and 64 atm at reaction temperature of 175 °C for 2 h incubation. The pretreated beech wood underwent an optimization step studying the effect of enzyme loading and solids content on the enzymatic liquefaction/saccharification prior to fermentation. In a custom designed free-fall mixer at 50 °C for either 6 or 12 h of prehydrolysis using an enzyme loading of 9 mg/g dry matter at 20 wt% initial solids content, high ethanol concentration of 75.9 g/L was obtained. The optimization of the pretreatment process allowed the efficient utilization of beech wood residual biomass for the production of high concentrations of cellulosic ethanol, while obtaining lignin that can be upgraded towards high-added-value chemicals. The threshold of 4 wt% ethanol concentration that is required for the sustainable bioethanol production was surpassed almost twofold

  13. Natural radiation dose of small mammalians in beech forest of Rokkasho, Japan

    International Nuclear Information System (INIS)

    Ohtsuka, Yoshihito; Iyogi, Takashi; Takaku, Yuichi; Hisamatsu, Shun'ichi

    2008-01-01

    Full text: Protection of the environment itself from radiation hazards is recognized as important as that of humans. Actual data on the background natural radiation dose, which is necessary to evaluate the effect of radiation, are very few, especially in the terrestrial environment. Forests around the Japan's first large scale nuclear fuel reprocessing plant in Rokkasho were selected as the research field for evaluating the background natural radiation to the environment. Data observed will be used in future for the comparison with the radiation dose from radionuclides released from the plant. Small mammalians, mouse (Apodeums argentus) and mole (Urotrichus talpoides), were selected as representative animals of the forests in this study, and it was planned to measure their radiation doses from natural sources; environmental γ-rays, Rn and internal radionuclides. The forests around the plant were classified into three types: beech, oak and coniferous. We have been measuring the natural radiation to the mammalians in each of those forests one by one and report the data for the beech forest here. The mammalians caught in traps in the beech forest during June-October, 2006 were analyzed for their natural radionuclides burdens ( 210 Pb, 210 Po, 40 K, 87 Rb, 226 Ra, 238 U and 232 Th) in 11 organs and carcass. Radiation dose rates from environmental γ-rays and atmospheric concentration of Rn in the forest were also measured during August-December, 2006. Mean internal dose rates of mouse and mole caught in June, 2006 were estimated to be 0.036 μGy h -1 and 0.28 μGy h -1 , respectively, from mean concentrations of the nuclides in a total body and internal dose conversion coefficients by FASSET. The difference of the dose between the two mammalian species was attributed to higher contribution of 210 Po in mole, in which dose reached 0.25 μGy h -1 in contrast to that in mouse of 0.016 μGy h -1 . The concentration of 210 Po in kidney of mole (0.37 Bq g -1 wet) was

  14. Flowering Trees

    Indian Academy of Sciences (India)

    branched evergreen shrub or small tree (6–7 m) with soft whitish-yellow wood. Branches are numerous and drooping. The leaves are elliptic-lanceolate and somewhat fleshy. Flowers are in loose axillary and terminal much-branched inflorescence, ...

  15. Flowering Trees

    Indian Academy of Sciences (India)

    narrow towards base. Flowers are large and attrac- tive, but emit unpleasant foetid smell. They appear in small numbers on erect terminal clusters and open at night. Stamens are numerous, pink or white. Style is slender and long, terminating in a small stigma. Fruit is green, ovoid and indistinctly lobed. Flowering Trees.

  16. ~{owering 'Trees

    Indian Academy of Sciences (India)

    Stamens are fused into a purple staminal tube that is toothed. Fruit is about 0.5 in. across, nearly globose, generally 5-seeded, green but yellow when ripe, quite smooth at first but wrinkled in drying, remaining long on the tree ajier ripening. The species is widely natural but occasionally cultivated for firewood as it grows very ...

  17. Flowering Trees

    Indian Academy of Sciences (India)

    Srimath

    quick-growing deciduous tree with a small crown. Branches are covered with dark conical prickles, which fall off after some time. The leaves are compound with three leaflets. Bright red or scarlet flowers which appear following leaf fall are in clusters at branch ends. Birds and bees visit flowers for nectar. Fruit is a cylindrical ...

  18. Flowering Trees

    Indian Academy of Sciences (India)

    deciduous tree with irregularly-shaped trunk, greyish-white scaly bark and milky latex. Leaves in opposite pairs are simple, oblong and whitish beneath. Flowers that occur in branched inflorescence are white, 2–. 3cm across and fragrant. Calyx is glandular inside. Petals bear numerous linear white scales, the corollary.

  19. Flowering Trees

    Indian Academy of Sciences (India)

    Muntingia calabura L. (Singapore cherry) of. Elaeocarpaceae is a medium size handsome ever- green tree. Leaves are simple and alternate with sticky hairs. Flowers are bisexual, bear numerous stamens, white in colour and arise in the leaf axils. Fruit is a berry, edible with several small seeds embedded in a fleshy pulp ...

  20. Flowering Trees

    Indian Academy of Sciences (India)

    Srimath

    . (6-10m high) evergreen tree with a straight trunk and broad open crown. Leaves are clustered at the end of twigs. They are dark green, broadest near the rounded apex and tapering towards the base with a short stalk. Flowers are greenish or ...

  1. ~{owering 'Trees

    Indian Academy of Sciences (India)

    size (upto 40 ft. high) deciduous tree with thick trunk, large crown of spreading branches and furrowed greenish-brown bark. (picture shows a young specimen). Leaves are 10-20 in. long, twice compound bearing numerous dark- green ...

  2. Flowering Trees

    Indian Academy of Sciences (India)

    Guaiacum officinale L. (LIGNUM-VITAE) of Zygophyllaceae is a dense-crowned, squat, knobbly, rough and twisted medium-sized ev- ergreen tree with mottled bark. The wood is very hard and resinous. Leaves are compound. The leaflets are smooth, leathery, ovate-ellipti- cal and appear in two pairs. Flowers (about 1.5.

  3. Flowering Trees

    Indian Academy of Sciences (India)

    IAS Admin

    Caesalpinia coriaria (Jacq.) Willd. (THE AMERICAN SUMACH, DIVI-DIVI) of. Caesalpiniaceae is a small unarmed tree reaching up to 10 m in height with a spreading crown. Leaves are alternate and twice compound. The flowers are small, about 0.6 cm (enlarged 5 times here), greenish-yellow, fragrant and appear in dense ...

  4. Flowering Trees

    Indian Academy of Sciences (India)

    Canthium parviflorum Lam. of Rubiaceae is a large shrub that often grows into a small tree with conspicuous spines. Leaves are simple, in pairs at each node and are shiny. Inflorescence is an axillary few-flowered cymose fascicle. Flowers are small (less than 1 cm across), 4-merous and greenish-white. Fruit is ellipsoid ...

  5. Flowering Trees

    Indian Academy of Sciences (India)

    Diospyros peregrina (Gaertn.) Guercke Syn. Diospyros embryopteris Pers., Diospyros malabarica Desr. (PALE MOON EBONY, RIBER EBONY) of Ebenaceae is a small or mid-sized slow-growing evergreen tree with spreading branches that form a dense crown. The bark is smooth, thick, dark and flakes off in large shreds.

  6. Flowering Trees

    Indian Academy of Sciences (India)

    Andira inermis (wright) DC. , Dog Almond of Fabaceae is a handsome lofty evergreen tree. Leaves are alternate and pinnately compound with 4–7 pairs of leaflets. Flowers are fragrant and are borne on compact branched inflorescences. Fruit is ellipsoidal one-seeded drupe that is peculiar to members of this family.

  7. :Ffowering 'Trees-

    Indian Academy of Sciences (India)

    The tree is a host of lac insects which secrete a resinous substance that yields shellac or lac. A ruby-coloured gum known as Bengal Kino is collected from the incisions made in the bark. The wood, resistant to water, is used in water-well work. The seeds are used as anthelmintic and as an antidote for snake-bite.

  8. Flowering Trees

    Indian Academy of Sciences (India)

    Trincomali Wood of Tiliaceae is a tall evergreen tree with straight trunk, smooth brownish-grey bark and simple broad leaves. Inflorescence is much branched with white flowers. Stamens are many with golden yellow anthers. Fruit is a capsule with six spreading wings. Seeds bear short stiff hairs that cause skin irritation.

  9. Tree Mortality

    Science.gov (United States)

    Mark J. Ambrose

    2012-01-01

    Tree mortality is a natural process in all forest ecosystems. However, extremely high mortality also can be an indicator of forest health issues. On a regional scale, high mortality levels may indicate widespread insect or disease problems. High mortality may also occur if a large proportion of the forest in a particular region is made up of older, senescent stands....

  10. Flowering Trees

    Indian Academy of Sciences (India)

    Sterculia foetida L. (INDIAN ALMOND,. JAVA OLIVE) of Sterculiaceae is a tall deciduous tree reaching a height of 20 m with faintly ridged grey bark. The bole reaches up to 2m in girth. Branches are reddish, usually horizontal. Leaves are large, palmately compound (5–7 leaflets) and clustered at the branch ends. Flowers ...

  11. Efficient modelling of foliage distribution and crown dynamics in monolayer tree species.

    Science.gov (United States)

    Beyer, Robert

    2017-12-01

    In response to the computational limitations of individual leaf-based tree growth models, this article presents a new approach for the efficient characterisation of the spatial distribution of foliage in monolayered trees in terms of 2D foliage surfaces. Much like the recently introduced 3D leaf area density, this concept accommodates local crown plasticity, which is a common weak point in large-scale growth models. Recognizing phototropism as the predominant driver of spatial crown expansion, we define the local light gradient on foliage surfaces. We consider the partial differential equation describing the evolution of a curve expanding along the light gradient and present an explicit solution. The article concludes with an illustration of the incorporation of foliage surfaces in a simple tree growth model for European beech (Fagus sylvatica L.), and discusses perspectives for applications in functional-structural models.

  12. Comparative study on the mechanical performance of beech and ash laminated panels

    Directory of Open Access Journals (Sweden)

    Andreea HEGYI

    2014-07-01

    Full Text Available This paper presents a comparative study on the mechanical performance of beech and ash wood laminated panels. Within the experimental study the bending strength, bending modulus of elasticity and the bonding characteristics to gluing (bonding quality were analyzed. The experimental results emphasized the influence of the type of wood, the panel thickness, the effect on the bending strength, respectively on the gluing quality of the direction of the wood lamellas in relation with the mechanical load (direction of cutting specimens. It can be said that the use of hardwood meets the needs and demands of the construction area, but it’s necessary a careful analysis of the requests that occur mainly at the site, thus an optimal direction of the wooden glued lamellas can be chosen. Laminated wood panels are a product with real physical and mechanical qualities, which can be successfully used to obtain construction elements that are bringing benefits to environmental quality of living areas.

  13. Study on Adhesion Strength of clear Coatings in Beech -Furfuryl alcohol wood polymer

    Directory of Open Access Journals (Sweden)

    Aisona Talaei

    2016-06-01

    Full Text Available The objective of this study was to determine the influence of Furfurylation treatment on adhesion strength of clear coatings and surface roughness of Beech (Fagus orientalis wood. Furfurylation of specimens were performed by impregnation and heat catalyze up to 20% and 65% weight percent gain. Half of the specimens coated with acid catalyst paint and half of them coated with polyurethane based paint. Surface roughness and adhesion strength (Pull-off and cross-hatch cutter test were analysed and compared to untreated specimens. Results revealed that 20% furfurylated specimens did not show significant difference in roughness and adhesion strength, compared to untreated control. But 65% furfurylated specimens caused decline in adhesion strength and raise in surface roughness. Polyurethane based paint had better efficiency and adhesion strength than acid catalyst paint. The highest adhesion strength observed in 20% furfurylated specimens coated with polyurethane and the least obtained in 65% furfurylated wood coated with acid catalyst paint.

  14. Characteristics of the soil in mountain beech communities on mountain Manjača

    Directory of Open Access Journals (Sweden)

    Eremija Saša

    2008-01-01

    Full Text Available The presented results of soil study, which will be used for defining the beech forest types of management unit 'Dubička Gora' on Mt. Manjača, are the basis for solving a series of current tasks of forestry profession. Relief and chemical nature of limestone are the main factors of the soil cover differentiation (Knežević, Košanin, 2004.. The results of physical and chemical soil properties are shown and its taxonomy is determined. Forest cover is represented by heterogeneous units-forest combinations. Four basic soil types are defined on the basis of detailed field and laboratory research: rendzina on dolomite, chernozem on limestone, brown soil on limestone, illimerised soil on limestone and dolomite.

  15. Determining the degree of fire retardancy of plywood with thermogravimetry, part I: Beech plywood

    Directory of Open Access Journals (Sweden)

    Gavrilović-Grmuša Ivana

    2007-01-01

    Full Text Available The basic motive of this work is the ever more pronounced need for fire-resistant plywood. In this work, beech veneers have been impregnated with solutions of chosen fire retardants, which are diammonium phosphate monoammonium phosphate, sodium acetate, water glass, sodium tetra borate and boric acid. To determine the preliminary level of fire retardancy achieved in veneers before manufacturing of finished plywood, thermo gravimetric (TG and derivative thermogravimetric (DTG methods are used. TG and DTG analyses of treated and untreated wood, as well as of fire retardants alone, were performed on a Perkin-Elmer TGS-2 thermo gravimetric equipment. Fire resistance of plywood was tested in accordance with standard test for resistance to the effects of fire and the most efficient fire retardants monoammonium phosphate and sodium tetra borate, had the same results as TG/DTG analyses, which points out the validity of TG methods in predicting success of fire retardants in future products.

  16. Tree-Ring Nitrogen Isotopes As Environmental Monitoring Tools - Inferring Air Quality Changes And Climate Effects

    Science.gov (United States)

    Savard, M. M.; Begin, C.; Smirnoff, A.; Marion, J.

    2008-12-01

    Anthropogenic emissions of atmospheric nitrogen greatly increased over the last 150 years, however the monitoring of nitrous oxide concentration in North America started only recently, generally during the last 30 years. Could the geochemical characteristics of tree rings be used to infer past changes in nitrogen cycles of temperate regions? To address this question we use long-term series (125 years) of nitrogen stable isotopes (δ15N) obtained from rings of pine (Pinus strobus) and beech (Fagus grandifolia) trees in the Montreal region (western Quebec), and of beech specimens in the Georgian Bay Islands National Park (central Ontario). Reliability tests of N concentrations in wood treated for removal of soluble materials reveal that the reproducibility from tree to tree is poor, and that the concentrations in both Pine and Beech trees change in the heartwood-sapwood transition zones. We therefore reject N concentration as environmental indicator. Alternatively, the N stable isotopes pass all reliability tests. In Montreal, short-term δ15N fluctuations correlate directly with precipitation and inversely with temperature. A long-term decreasing isotope trend suggests progressive changes in soil chemistry after 1951. A pedochemical change is also inferred for the Georgian Bay site on the basis of a positive δ15N trend initiated after 1971. At both sites, the long-term δ15N series correlate with a proxy for NOx emissions, and the δ13C values of the same ring series suggest that all studied trees have been stressed by phytotoxic pollutants. We propose that the contrasted long-term δ15N changes of Montreal and Georgian Bay reflect deposition of NOx emissions from cars and coal-power plants, with higher proportions from coal burning in Georgian Bay. This interpretation is conceivable because recent monitoring indicates that coal-power plant NOx emissions play an important role in the annual N budget in Ontario, but they seem negligible on the Quebec side. This

  17. The influence of seedling density in containers on morphological characteristics of European beech

    Directory of Open Access Journals (Sweden)

    Wrzesiński Piotr

    2015-09-01

    Full Text Available This study examines the influence on growth parameters, in particular the morphological features of the root system, of 1-year-old European beech seedlings cultivated in containers with two different densities. The experiment was conducted in the container nursery in Skierdy (Forest District of Jabłonna in spring 2011. After 10 months of cultivation in Hiko polyethylene containers, above- and below-ground parts of the seedlings were measured. The measurements of the root system were conducted with a scanner and the WinRHIZO software. No influence due to the seedling density on either shoot height or thickness was observed, but instead the research showed that different seedling densities affected the development of root systems. The mean root thickness and dry mass of the European beech seedlings were significantly higher at the lower density. The influence of seedling density on the development of root mass deserves special attention as it is the most important factor affecting future growth of the seedlings during cultivation. This tendency also suggests that the amount of nutrients allocated to shoot development may be higher in order to improve the efficiency of photosynthesis. At both densities, differences in biomass accumulation affected the root-toshoot ratio. In seedlings cultivated at the lower density, the increased dry root matter of the seedlings resulted in a significant increase in the root-to-shoot ratio. This may cause a potential growth advantage of these seedlings after they are planted and may thus result in a more productive cultivation.

  18. Forty-two years of change in an old-growth and second-growth beech-maple forest of north central Ohio

    Science.gov (United States)

    Natalie R. Pinheiro; P. Charles Goebel; David M. Hix

    2008-01-01

    Using data collected in 1964 and 2006, we examined changes in the composition and structure of a second-growth and old-growth beech-maple forest of Crall Woods, located in Ashland County of north central Ohio. Over the 42 years, the old-growth forest (estimated to be at least 250 years old) experienced a significant shift in species composition as American beech,...

  19. Coppice Woods and Pollard Trees in the Visual Arts

    Directory of Open Access Journals (Sweden)

    Lacina Jan

    2016-11-01

    Full Text Available The sprouting capacity of some broadleaves has been used for their regeneration since ancient times. Often concurrently with taking advantage of sprouting stools, the trees used to be shaped also by pruning their stems, namely on pasturelands and in grazing forests. The activity of woodcutters and shepherds was obviously rather common in warmer climates with broadleaved stands because coppice and pollard trees appear relatively often in the visual arts from ancient works through the period if the Italian and German Renaissance up to the romantic and realistic landscape painting of the 19th century overlapping into the 20th century. For centuries, most frequently illustrated in European and Czech paintings have been pollard willows (Salix spp.. Other coppice and pollard tree species identified in paintings are oaks (Quercus spp., hornbeam (Carpinus betulus, European beech (Fagus sylvatica, European chestnut (Castanea sativa, and rarely other species, too. Artists apparently often used bizarrely shaped woods to increase the dramatic atmosphere of their landscape sceneries as well as figural compositions, and the coppice and pollard trees had certainly also a symbolic meaning in some of their works.

  20. Comparison of the chemical properties of wheat straw and beech fibers following alkaline wet oxidation and laccase treatments

    DEFF Research Database (Denmark)

    Schmidt, A. S.; Mallon, S.; Thomsen, Anne Belinda

    2002-01-01

    reacted differently in the two processes. The chemical composition changed little following enzyme treatment. After alkaline wet oxidation, fibers enriched in cellulose were obtained. With both materials, almost all hemicellulose (80%) together with a large portion of the lignin were solubilised......Wheat straw (Triticum aestivum) and beech (Fagus sylvatica), were used to evaluate the effects of two pre-treatment processes (alkaline wet oxidation and enzyme treatment with laccase) on lignocellulosic materials for applications in particleboards and fiberboards. Wheat straw and beech fibers...... by alkaline wet oxidation, but essentially all cellulose remained in the solid fraction. Following enzyme treatment most material remained as a solid. For wheat straw, reaction with acetic anhydride indicated that both treatments resulted in more hydroxyl groups being accessible for reaction. The enzyme...

  1. Effect of temperate climate tree species on gross ammonification, gross nitrification and N2O formation

    Science.gov (United States)

    Brüggemann, N.; Rosenkranz, P.; Papen, H.; Butterbach-Bahl, K.

    2003-04-01

    Microbial nitrogen turnover processes in the soil, like ammonification, nitrification and denitrification, play an important role in the formation of nitrous oxide (N2O): (i) ammonification, because it releases nitrogen from organic material in the form of ammonium (NH4+), which in turn can serve as substrate for nitrification; (ii) nitrification itself (i.e. the turnover of NH4+ to nitrate, NO3-), during which nitric oxide (NO) and N2O can be released as by-products at varying ratios; (iii) denitrification, in which NO3- serves as electron acceptor and is converted to molecular nitrogen (N2) via NO and N2O as intermediates, that can also be partially lost to the atmosphere. Temperate forest soils are a substantial source of atmospheric N2O contributing up to 10% to the total atmospheric N2O budget. However, this figure is afflicted with a huge uncertainty due to a number of factors governing the soil N2O formation, consumption, release and uptake, which are not fully understood at present. To one of these factors belongs the influence of the tree species on nitrogen turnover processes in the soil and the formation of N trace gases related with them. The aim of the present work was to analyse this tree species effect for the temperate climate region. For this purpose the effect of five different temperate tree species, having the same age and growing on the same soil in direct vicinity to each other, on gross ammonification and gross nitrification as well as on N2O formation was investigated. The trees (common beech, Fagus sylvatica; pedunculate oak, Quercus robur; Norway spruce, Picea abies; Japanese larch, Larix leptolepis; mountain pine, Pinus mugo) were part of a species trial in Western Jutland, Denmark, established in 1965 on a former sandy heathland. Samples from the soil under these five tree species were taken in spring and in summer 2002, respectively, differentiating between organic layer and mineral soil. The gross rates of ammonification as well of

  2. Surface tree languages and parallel derivation trees

    NARCIS (Netherlands)

    Engelfriet, Joost

    1976-01-01

    The surface tree languages obtained by top-down finite state transformation of monadic trees are exactly the frontier-preserving homomorphic images of sets of derivation trees of ETOL systems. The corresponding class of tree transformation languages is therefore equal to the class of ETOL languages.

  3. Influence of litter diversity on dissolved organic matter release and soil carbon formation in a mixed beech forest.

    Directory of Open Access Journals (Sweden)

    Andrea Scheibe

    Full Text Available We investigated the effect of leaf litter on below ground carbon export and soil carbon formation in order to understand how litter diversity affects carbon cycling in forest ecosystems. 13C labeled and unlabeled leaf litter of beech (Fagus sylvatica and ash (Fraxinus excelsior, characterized by low and high decomposability, were used in a litter exchange experiment in the Hainich National Park (Thuringia, Germany. Litter was added in pure and mixed treatments with either beech or ash labeled with 13C. We collected soil water in 5 cm mineral soil depth below each treatment biweekly and determined dissolved organic carbon (DOC, δ13C values and anion contents. In addition, we measured carbon concentrations and δ13C values in the organic and mineral soil (collected in 1 cm increments up to 5 cm soil depth at the end of the experiment. Litter-derived C contributes less than 1% to dissolved organic matter (DOM collected in 5 cm mineral soil depth. Better decomposable ash litter released significantly more (0.50±0.17% litter carbon than beech litter (0.17±0.07%. All soil layers held in total around 30% of litter-derived carbon, indicating the large retention potential of litter-derived C in the top soil. Interestingly, in mixed (ash and beech litter treatments we did not find a higher contribution of better decomposable ash-derived carbon in DOM, O horizon or mineral soil. This suggest that the known selective decomposition of better decomposable litter by soil fauna has no or only minor effects on the release and formation of litter-derived DOM and soil organic matter. Overall our experiment showed that 1 litter-derived carbon is of low importance for dissolved organic carbon release and 2 litter of higher decomposability is faster decomposed, but litter diversity does not influence the carbon flow.

  4. Influence of litter diversity on dissolved organic matter release and soil carbon formation in a mixed beech forest.

    Science.gov (United States)

    Scheibe, Andrea; Gleixner, Gerd

    2014-01-01

    We investigated the effect of leaf litter on below ground carbon export and soil carbon formation in order to understand how litter diversity affects carbon cycling in forest ecosystems. 13C labeled and unlabeled leaf litter of beech (Fagus sylvatica) and ash (Fraxinus excelsior), characterized by low and high decomposability, were used in a litter exchange experiment in the Hainich National Park (Thuringia, Germany). Litter was added in pure and mixed treatments with either beech or ash labeled with 13C. We collected soil water in 5 cm mineral soil depth below each treatment biweekly and determined dissolved organic carbon (DOC), δ13C values and anion contents. In addition, we measured carbon concentrations and δ13C values in the organic and mineral soil (collected in 1 cm increments) up to 5 cm soil depth at the end of the experiment. Litter-derived C contributes less than 1% to dissolved organic matter (DOM) collected in 5 cm mineral soil depth. Better decomposable ash litter released significantly more (0.50±0.17%) litter carbon than beech litter (0.17±0.07%). All soil layers held in total around 30% of litter-derived carbon, indicating the large retention potential of litter-derived C in the top soil. Interestingly, in mixed (ash and beech litter) treatments we did not find a higher contribution of better decomposable ash-derived carbon in DOM, O horizon or mineral soil. This suggest that the known selective decomposition of better decomposable litter by soil fauna has no or only minor effects on the release and formation of litter-derived DOM and soil organic matter. Overall our experiment showed that 1) litter-derived carbon is of low importance for dissolved organic carbon release and 2) litter of higher decomposability is faster decomposed, but litter diversity does not influence the carbon flow.

  5. Long-term tree inventory data from mountain forest plots in France.

    Science.gov (United States)

    Fuhr, Marc; Cordonnier, Thomas; Courbaud, Benoît; Kunstler, Georges; Mermin, Eric; Riond, Catherine; Tardif, Pascal

    2017-04-01

    We present repeated tree measurement data from 63 permanent plots in mountain forests in France. Plot elevations range from 800 (lower limit of the montane belt) to 1942 m above sea level (subalpine belt). Forests mainly consist of pure or mixed stands dominated by European beech (Fagus sylvatica), Silver fir (Abies alba), and Norway spruce (Picea abies), in association with various broadleaved species at low elevation and with Arolla pine (Pinus cembra) at high elevation. The plot network includes 23 plots in stands that have not been managed for the last 40 years (at least) and 40 plots in plots managed according to an uneven-aged system with single-tree or small-group selection cutting. Plot sizes range from 0.2 to 1.9 ha. Plots were installed from 1994 to 2004 and remeasured two to five times during the 1994-2015 period. During the first census (installation), living trees more than 7.5 cm in dbh were identified, their diameter at breast height (dbh) was measured and their social status (strata) noted. Trees were spatially located, either with x, y, and z coordinates (40 plots) or within 0.25-ha square subplots (23 plots). In addition, in a subset of plots (58 plots), tree heights and tree crown dimensions were measured on a subset of trees and dead standing trees and stumps were included in the census. Remeasurements after installation include live tree diameters (including recruited trees), tree status (living, damaged, dead, stump), and for a subset of trees, height. At the time of establishment of the plots, plot densities range from 181 to 1328 stems/ha and plot basal areas range from 13.6 to 81.3 m 2 /ha. © 2017 by the Ecological Society of America.

  6. A discrete element modelling approach for block impacts on trees

    Science.gov (United States)

    Toe, David; Bourrier, Franck; Olmedo, Ignatio; Berger, Frederic

    2015-04-01

    These past few year rockfall models explicitly accounting for block shape, especially those using the Discrete Element Method (DEM), have shown a good ability to predict rockfall trajectories. Integrating forest effects into those models still remain challenging. This study aims at using a DEM approach to model impacts of blocks on trees and identify the key parameters controlling the block kinematics after the impact on a tree. A DEM impact model of a block on a tree was developed and validated using laboratory experiments. Then, key parameters were assessed using a global sensitivity analyse. Modelling the impact of a block on a tree using DEM allows taking into account large displacements, material non-linearities and contacts between the block and the tree. Tree stems are represented by flexible cylinders model as plastic beams sustaining normal, shearing, bending, and twisting loading. Root soil interactions are modelled using a rotation stiffness acting on the bending moment at the bottom of the tree and a limit bending moment to account for tree overturning. The crown is taken into account using an additional mass distribute uniformly on the upper part of the tree. The block is represented by a sphere. The contact model between the block and the stem consists of an elastic frictional model. The DEM model was validated using laboratory impact tests carried out on 41 fresh beech (Fagus Sylvatica) stems. Each stem was 1,3 m long with a diameter between 3 to 7 cm. Wood stems were clamped on a rigid structure and impacted by a 149 kg charpy pendulum. Finally an intensive simulation campaign of blocks impacting trees was done to identify the input parameters controlling the block kinematics after the impact on a tree. 20 input parameters were considered in the DEM simulation model : 12 parameters were related to the tree and 8 parameters to the block. The results highlight that the impact velocity, the stem diameter, and the block volume are the three input

  7. Attraction and antennal response of the common wasp, Vespula vulgaris (L.), to selected synthetic chemicals in New Zealand beech forests.

    Science.gov (United States)

    El-Sayed, Ashraf M; Manning, Lee-Anne; Unelius, C Rikard; Park, Kye Chung; Stringer, Lloyd D; White, Nicola; Bunn, Barry; Twidle, Andrew; Suckling, David M

    2009-09-01

    The common wasp, Vespula vulgaris (L.), and the German wasp, Vespula germanica (F.), are significant problems in New Zealand beech forests (Nothofagus spp.), adversely affecting native birds and invertebrate biodiversity. This work was undertaken to develop synthetic attractants for these species to enable more efficient monitoring and management. Seven known wasp attractants (acetic acid, butyl butyrate, isobutanol, heptyl butyrate, octyl butyrate and 2,4-hexadienyl butyrate) were field tested, and only heptyl butyrate and octyl butyrate attracted significantly higher numbers of wasps than a non-baited trap. Accordingly, a series of straight-chain esters from methyl to decyl butyrate were prepared and field tested for attraction of social wasps. Peak biological activity occurred with hexyl butyrate, heptyl butyrate, octyl butyrate and nonyl butyrate. Polyethylene bags emitting approximately 18.4-22.6 mg day(-1) of heptyl butyrate were more attractive than polyethylene bags emitting approximately 14.7-16.8 mg day(-1) of heptyl butyrate in the field. Electroantennogram (EAG) studies indicated that queens and workers of V. vulgaris had olfactory receptor neurons responding to various aliphatic butyrates. These results are the first to be reported on the EAG response and the attraction of social wasps to synthetic chemicals in New Zealand beech forests and will enable monitoring of social wasp activity in beech forests. Copyright 2009 Society of Chemical Industry.

  8. Trees are good, but…

    Science.gov (United States)

    E.G. McPherson; F. Ferrini

    2010-01-01

    We know that “trees are good,” and most people believe this to be true. But if this is so, why are so many trees neglected, and so many tree wells empty? An individual’s attitude toward trees may result from their firsthand encounters with specific trees. Understanding how attitudes about trees are shaped, particularly aversion to trees, is critical to the business of...

  9. Seasonal variations of belowground carbon transfer assessed by in situ 13CO2 pulse labelling of trees

    Directory of Open Access Journals (Sweden)

    L. Barthes

    2011-05-01

    Full Text Available Soil CO2 efflux is the main source of CO2 from forest ecosystems and it is tightly coupled to the transfer of recent photosynthetic assimilates belowground and their metabolism in roots, mycorrhiza and rhizosphere microorganisms feeding on root-derived exudates. The objective of our study was to assess patterns of belowground carbon allocation among tree species and along seasons. Pure 13CO2 pulse labelling of the entire crown of three different tree species (beech, oak and pine was carried out at distinct phenological stages. Excess 13C in soil CO2 efflux was tracked using tuneable diode laser absorption spectrometry to determine time lags between the start of the labelling and the appearance of 13C in soil CO2 efflux and the amount of 13C allocated to soil CO2 efflux. Isotope composition (δ13C of CO2 respired by fine roots and soil microbes was measured at several occasions after labelling, together with δ13C of bulk root tissue and microbial carbon. Time lags ranged from 0.5 to 1.3 days in beech and oak and were longer in pine (1.6–2.7 days during the active growing season, more than 4 days during the resting season, and the transfer of C to the microbial biomass was as fast as to the fine roots. The amount of 13C allocated to soil CO2 efflux was estimated from a compartment model. It varied between 1 and 21 % of the amount of 13CO2 taken up by the crown, depending on the species and the season. While rainfall exclusion that moderately decreased soil water content did not affect the pattern of carbon allocation to soil CO2 efflux in beech, seasonal patterns of carbon allocation belowground differed markedly between species, with pronounced seasonal variations in pine and beech. In beech, it may reflect competition with the strength of other sinks (aboveground growth in late spring and storage in late summer that were not observed in oak. We report a fast transfer of recent photosynthates to the mycorhizosphere and we conclude that the

  10. Seasonal variations of belowground carbon transfer assessed by in situ 13CO2 pulse labelling of trees

    Science.gov (United States)

    Epron, D.; Ngao, J.; Dannoura, M.; Bakker, M. R.; Zeller, B.; Bazot, S.; Bosc, A.; Plain, C.; Lata, J. C.; Priault, P.; Barthes, L.; Loustau, D.

    2011-05-01

    Soil CO2 efflux is the main source of CO2 from forest ecosystems and it is tightly coupled to the transfer of recent photosynthetic assimilates belowground and their metabolism in roots, mycorrhiza and rhizosphere microorganisms feeding on root-derived exudates. The objective of our study was to assess patterns of belowground carbon allocation among tree species and along seasons. Pure 13CO2 pulse labelling of the entire crown of three different tree species (beech, oak and pine) was carried out at distinct phenological stages. Excess 13C in soil CO2 efflux was tracked using tuneable diode laser absorption spectrometry to determine time lags between the start of the labelling and the appearance of 13C in soil CO2 efflux and the amount of 13C allocated to soil CO2 efflux. Isotope composition (δ13C) of CO2 respired by fine roots and soil microbes was measured at several occasions after labelling, together with δ13C of bulk root tissue and microbial carbon. Time lags ranged from 0.5 to 1.3 days in beech and oak and were longer in pine (1.6-2.7 days during the active growing season, more than 4 days during the resting season), and the transfer of C to the microbial biomass was as fast as to the fine roots. The amount of 13C allocated to soil CO2 efflux was estimated from a compartment model. It varied between 1 and 21 % of the amount of 13CO2 taken up by the crown, depending on the species and the season. While rainfall exclusion that moderately decreased soil water content did not affect the pattern of carbon allocation to soil CO2 efflux in beech, seasonal patterns of carbon allocation belowground differed markedly between species, with pronounced seasonal variations in pine and beech. In beech, it may reflect competition with the strength of other sinks (aboveground growth in late spring and storage in late summer) that were not observed in oak. We report a fast transfer of recent photosynthates to the mycorhizosphere and we conclude that the patterns of carbon

  11. Production dynamics of fine roots in beech forests: possible mechanism of resource allocation between above- and below-ground production

    Science.gov (United States)

    Nakahata, R.; Osawa, A.; Naramoto, M.; Mizunaga, H.; Sato, M.

    2017-12-01

    The masting phenomenon that seed production has large annual variation with spatial synchrony appears generally in beeches. Therefore, net primary production and carbon allocation mechanism in beech forests may differ among several years in relation to annual variation of seed production. On the other hand, fine roots play key roles in carbon dynamics and nutrient and water acquisition of an ecosystem. Evaluation of fine root dynamics is essential to understand long-term dynamics of production in forest ecosystems. Moreover, the influence of mast seeding on resource allocation should be clarified in such beech forests. The aim of this study is to clarify possible relationships between the patterns of above- and below-ground production in relation to the masting events using observation data of litter fall and fine root dynamics. We applied the litter trap method and a minirhizotron method in a cool-temperate natural forest dominated by beech (Fagus crenata Blume). Ten litter traps were set from 2008 to 2016, then annual leaf and seed production were estimated. Four minirhizotron tubes were buried in Aug. 2008 and soil profiles were scanned monthly until Nov. 2016 during the periods of no snow covering. The scanned soil profiles were analyzed for calculating fine root production using the WinRHIZO Tron software. In the present study site, rich production of mast seeding occurred biennially and fine root production showed various seasonal patterns. There was no significant correlation between seed production and annual fine root production in the same year. However, seed production had a positive correlation with fine root production in autumn in the previous year and indicated a negative correlation with that in autumn in the current year. These results indicate that higher fine root production has led to increased nutrient acquisition, which resulted in rich seed production in the next year. It is also suppressed after the masting events due to shortage in

  12. Simple street tree sampling

    Science.gov (United States)

    David J. Nowak; Jeffrey T. Walton; James Baldwin; Jerry. Bond

    2015-01-01

    Information on street trees is critical for management of this important resource. Sampling of street tree populations provides an efficient means to obtain street tree population information. Long-term repeat measures of street tree samples supply additional information on street tree changes and can be used to report damages from catastrophic events. Analyses of...

  13. Programming macro tree transducers

    DEFF Research Database (Denmark)

    Bahr, Patrick; Day, Laurence E.

    2013-01-01

    A tree transducer is a set of mutually recursive functions transforming an input tree into an output tree. Macro tree transducers extend this recursion scheme by allowing each function to be defined in terms of an arbitrary number of accumulation parameters. In this paper, we show how macro tree ...

  14. Modular tree automata

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2012-01-01

    Tree automata are traditionally used to study properties of tree languages and tree transformations. In this paper, we consider tree automata as the basis for modular and extensible recursion schemes. We show, using well-known techniques, how to derive from standard tree automata highly modular r...

  15. Role of six European tree species and land-use legacy for nitrogen and water budgets in forests

    DEFF Research Database (Denmark)

    Riis Christiansen, Jesper; Vesterdal, Lars; Callesen, Ingeborg

    2010-01-01

    -year-old common garden design with stands of common ash (Fraxinus excelsior), European beech (Fagus sylvatica L.), pedunculate oak (Quercus robur), small-leaved lime (Tilia cordata Mill.), sycamore maple (Acer pseudoplatanus) and Norway spruce (Picea abies [L.] Karst.) replicated at two sites...... leaching of N was significantly higher at Mattrup than at Vallø. Accordingly, the sites differed in soil properties in relation to rates and dynamics of N cycling. We conclude that tree species affect the N cycle differently but the legacy of land use exerted a dominant control on the N cycle within...

  16. Gap formation in Danish beech (Fagus sylvatica) forests of low management intensity

    DEFF Research Database (Denmark)

    Ritter, Eva; Vesterdal, Lars

    2006-01-01

    -based managed forest, soil solution was collected for 5 years and soil moisture measured in the fourth year after gap formation. Average NO3-N concentrations were significantly higher in the gaps (9.9 and 8.1 mg NO3-N l(-1), respectively) than under closed canopy (0.2 mg l(-1)). In the semi-natural forest....... In the semi-natural forest, advanced regeneration and lateral closure of the gap affected soil moisture levels in the gap in the last year of the study. Author Keywords: gaps; drainage fluxes; Fagus sylvatica L.; nitrate; soil moisture; soil solution; unmanaged forest ecosystems; WATBAL......Soil moisture content (0-90 cm depth) and nitrate-nitrogen (NO3-N) concentrations in soil solution (90 cm depth) were monitored after gap formation (diameter 15-18 m) in three Danish beech-dominated forests on nutrient-rich till soils. NO3-N drainage losses were estimated by the water balance model...

  17. Fine root dynamics of mature European beech (Fagus sylvatica L.) as influenced by elevated ozone concentrations

    International Nuclear Information System (INIS)

    Mainiero, Raphael; Kazda, Marian; Haeberle, Karl-Heinz; Nikolova, Petia Simeonova; Matyssek, Rainer

    2009-01-01

    Fine root dynamics (diameter < 1 mm) in mature Fagus sylvatica, with the canopies exposed to ambient or twice-ambient ozone concentrations, were investigated throughout 2004. The focus was on the seasonal timing and extent of fine root dynamics (growth, mortality) in relation to the soil environment (water content, temperature). Under ambient ozone concentrations, a significant relationship was found between fine root turnover and soil environmental changes indicating accelerated fine root turnover under favourable soil conditions. In contrast, under elevated ozone, this relationship vanished as the result of an altered temporal pattern of fine root growth. Fine root survival and turnover rate did not differ significantly between the different ozone regimes, although a delay in current-year fine root shedding was found under the elevated ozone concentrations. The data indicate that increasing tropospheric ozone levels can alter the timing of fine root turnover in mature F. sylvatica but do not affect the turnover rate. - Doubling of ozone concentrations in mature European beech affected the seasonal timing of fine root turnover rather than the turnover rate.

  18. Modeling and Simulation of Pyrolysis Process for a Beech Wood Material

    Directory of Open Access Journals (Sweden)

    I. M. Idriss

    2017-12-01

    Full Text Available Modeling and simulation of beech wood was carried out using Aspen Plus simulation commercial package. The model was created based on pyrolysis product yield, proximate and ultimate analysis of the wood species. In the model development, RYield was used to represent pyrolysis reactor as a non- stoichiometric type that decomposes the wood into categories of conventional compounds. The model was simulated to give the components compositions in both gaseous and liquid products. The simulation was first conducted at a temperature of 450oC, for range of feed particle sizes from 1.6-2.0 mm, using atmospheric pressure. Five different runs were carried out by varying their temperatures and particle size. The investigation revealed the effect of pyrolysis temperature and wood particle size on compositions of liquid and gaseous products. The results showed that production of methanol increases with temperature but decreases at temperatures beyond 550oC. Carbon dioxide yield decreases with increase in temperature while that of carbon monoxide and methane get higher as temperature increases.

  19. The influence of fire retardants on the properties of beech and poplar veneers and plywood

    Directory of Open Access Journals (Sweden)

    Miljković Jovan

    2005-01-01

    Full Text Available Rising demands for fire resistance properties of wood construction and elements matching new standards have been an important part of building codes during the last decade. On the other side, lack of more detailed research on interaction between wood species and selected fire retardant chemicals even with basically one is evident. This is particularly truth with domestic wood species. In this research, beech and poplar veneers were immersed in 25% solutions of monoammonium phosphate (MP and sodium acetate (SA and impregnated for different periods of time. To determine the preliminary level of fire retardancy achieved in veneers before manufacturing of finished plywood, thermo gravimetric (TG and derivative thermo gravimetric (DTG methods were used. TG and DTG analyses of treated and untreated wood, as well as of fire retardants alone, were performed. The next properties of impregnated and no impregnated veneers and plywood were determined: absorption of imp regnant solution (A, weight percent gain (WPG of imp regnant, equilibrium moisture content (EMC, pH values, and in the case of plywood, strength and fire resistance. Fire resistance of plywood was tested in accordance with standard test for resistance to the effects of fire and the most efficient fire retardant, monoammonium phosphate, had the same result as TG/DTG analyses, which pointed out the validity of TG methods in predicting fire resistance of future products.

  20. Thermal conductivity of the amorphous and nanocrystalline phases of the beech wood biocarbon nanocomposite

    Science.gov (United States)

    Kartenko, N. F.; Orlova, T. S.; Parfen'eva, L. S.; Smirnov, B. I.; Smirnov, I. A.

    2014-11-01

    Natural composites (biocarbons) obtained by carbonization of beech wood at different carbonization temperatures T carb in the range of 800-2400°C have been studied using X-ray diffraction. The composites consist of an amorphous matrix and nanocrystallites of graphite and graphene. The volume fractions of the amorphous and nanocrystalline phases as functions of T carb have been determined. Temperature dependences of the phonon thermal conductivity κ( T) of the biocarbons with different temperatures T carb (1000 and 2400°C) have been analyzed in the range of 5-300 K. It has been shown that the behavior of κ( T) of the biocarbon with T carb = 1000°C is controlled by the amorphous phase in the range of 5-50 K and by the nanocrystalline phase in the range of 100-300 K. The character of κ( T) of the biocarbon with T carb = 2400°C is determined by the heat transfer (scattering) in the nanocrystalline phase over the entire temperature range of 5-300 K.

  1. Thermal conductivity at the amorphous-nanocrystalline phase transition in beech wood biocarbon

    Science.gov (United States)

    Parfen'eva, L. S.; Orlova, T. S.; Smirnov, B. I.; Smirnov, I. A.; Misiorek, H.; Jezowski, A.; Ramirez-Rico, J.

    2014-05-01

    High-porosity samples of beech wood biocarbon (BE-C) were prepared by pyrolysis at carbonization temperatures T carb = 650, 1300, and 1600°C, and their resistivity ρ and thermal conductivity κ were studied in the 5-300 and 80-300 K temperature intervals. The experimental results obtained were evaluated by invoking X-ray diffraction data and information on the temperature dependences ρ( T) and κ( T) for BE-C samples prepared at T carb = 800, 1000, and 2400°C, which were collected by the authors earlier. An analysis of the κ( T carb) behavior led to the conclusion that the samples under study undergo an amorphous-nanocrystalline phase transition in the interval 800°C < T carb < 1000°C. Evaluation of the electronic component of the thermal conductivity revealed that the Lorentz number of the sample prepared at T carb = 2400°C exceeds by far the classical Sommerfeld value, which is characteristic of metals and highly degenerate semiconductors.

  2. Specific features of the electrical properties in partially graphitized porous biocarbons of beech wood

    Science.gov (United States)

    Popov, V. V.; Orlova, T. S.; Gutierrez-Pardo, A.; Ramirez-Rico, J.

    2015-09-01

    The electrical and galvanomagnetic properties of partially graphitized highly porous bioC(Ni) biocarbon matrices produced by pyrolysis (carbonization) of beech wood at temperatures T carb = 850-1600°C in the presence of a Ni-containing catalyst have been studied in comparison with their microstructural features. The temperature dependences of the resistivity, the magnetoresistance, and the Hall coefficient have been measured in the temperature range of 4.2-300 K in magnetic fields to 28 kOe. It has been shown that an additional graphite phase introduction into samples with T carb ≥ 1000°C results in an increase in the carrier mobility by a factor of 2-3, whereas the carrier (hole) concentration remains within ~1020 cm-3, as in biocarbons obtained without catalyst. An analysis of experimental data has demonstrated that the features of the conductivity and magnetoresistance of these samples are described by quantum corrections related to their structural features, i.e., the formation of a globular graphite phase of nano- and submicrometer sizes in the amorphous matrix. The quantum corrections to the conductivity decrease with increasing carbonization temperature, which indicates an increase in the degree of structure ordering and is in good agreement with microstructural data.

  3. Factors affecting industrial wood, material production yield in Turkey’s natural beech forests

    Directory of Open Access Journals (Sweden)

    Atilla Atik

    2014-07-01

    Full Text Available The objectives of the present study are to determine the most important factors affecting industrial wood material production yield in natural oriental beech forests in Turkey using a multifaceted approach and to help entrepreneurs consider these factors to develop more sensitive and realistic production plans. In Günye Forest Management in Bartın province of the West Black Sea Region of Turkey, 41 production units were chosen as the study area. The 1277 ha study area was included in the 2007 and 2010 production management plan. The general state of the stand, natural stand structure, and production methods and tools are the factors thought most strongly affect industrial wood material production yield; 26 variables representing these factors were evaluated in the study. Through multidimensional statistical analyses, including main components, factor and regression  analysis, we found that the most important factors affecting production yield were fertility, aspect of land, skidding method, stand structure, skidding distance, growing stock, transportation and harmful abiotic factors. Production units were divided into three groups based on yield rates and the 26 variables, using discriminate analysis. From the results of the study, a sample model can be developed to help forest managers predict and plan annual industrial wood production more sensitively and realistically.

  4. City of Pittsburgh Trees

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Trees cared for and managed by the City of Pittsburgh Department of Public Works Forestry Division. Tree Benefits are calculated using the National Tree Benefit...

  5. Spatial pattern of tree diversity and evenness across forest types in Majella National Park, Italy

    Directory of Open Access Journals (Sweden)

    Mohammad Redowan

    2015-09-01

    Full Text Available Background Estimation of tree diversity at broader scale is important for conservation planning. Tree diversity should be measured and understood in terms of diversity and evenness, two integral components to describe the structure of a biological community. Variation of the tree diversity and evenness with elevation, topographic relief, aspect, terrain shape, slope, soil nutrient, solar radiation etc. are well documented. Methods Present study explores the variation of tree diversity (measured as Shannon diversity and evenness indices of Majella National Park, Italy with five available forest types namely evergreen oak woods, deciduous oak woods, black/aleppo pine stands, hop-hornbeam forest and beech forest, using satellite, environmental and field data. Results Hop-hornbeam forest was found to be most diverse and even while evergreen Oak woods was the lowest diverse and even. Diversity and evenness of forest types were concurrent to each other i.e. forest type which was more diverse was also more even. As a broad pattern, majority portion of the study area belonged to medium diversity and high evenness class. Conclusions Satellite images and other GIS data proved useful tools in monitoring variation of tree diversity and evenness across various forest types. Present study findings may have implications in prioritizing conservation zones of high tree diversity at Majella.

  6. Făgetele primare din România, o contribuţie la Patrimoniul Mondial UNESCO [Romania’s primary beech forests, a contribution to UNESCO World Heritage

    Directory of Open Access Journals (Sweden)

    Iovu Adrian Biriș

    2014-08-01

    Full Text Available The World Heritage List (WHL of UNESCO currently comprises 1007 properties in 161 States Parties. Most of these sites are cultural (779 and only 197 are natural sites whereas 31 are mixed sites with outstanding universal cultural and natural values. Romania has only 8 sites registered on WHL of UNESCO, 7 cultural sites and one natural site – The Danube Delta Biosphere Reserve - being underrepresented in relation with the real value of its natural patrimony. Beech is a deciduous species exclusively European and the beech forests constitute the potential natural vegetation for the temperate zone of Europe. Beech forests represent an outstanding and globally unparalleled example of the ongoing ecological processes of post-glacial expansion. This is a key factor for supporting the nomination of beech forests under WHL of UNESCO. Romania, the country with the larges area of beech forests and well preserved primary beech forests, has an important responsibility for the conservation of an adequate and representative network of beech forests. Considering these aspects, the Ministry of the Environment and Climate Change - Department for Waters, Forests and Fisheries, National Forest Administration – Romsilva, Forest Research and Management Institute, WWF Danube-Carpathian Programme Office and Greenpeace CEE Romania Foundation have signed a protocol for collaboration having as target the selection of certain beech forests to be included on the WHL of UNESCO. Keywords

  7. Biomass and morphology of fine roots in temperate broad-leaved forests differing in tree species diversity: is there evidence of below-ground overyielding?

    Science.gov (United States)

    Meinen, Catharina; Hertel, Dietrich; Leuschner, Christoph

    2009-08-01

    Biodiversity effects on ecosystem functioning in forests have only recently attracted increasing attention. The vast majority of studies in forests have focused on above-ground responses to differences in tree species diversity, while systematic analyses of the effects of biodiversity on root systems are virtually non-existent. By investigating the fine root systems in 12 temperate deciduous forest stands in Central Europe, we tested the hypotheses that (1) stand fine root biomass increases with tree diversity, and (2) 'below-ground overyielding' of species-rich stands in terms of fine root biomass is the consequence of spatial niche segregation of the roots of different species. The selected stands represent a gradient in tree species diversity on similar bedrock from almost pure beech forests to medium-diverse forests built by beech, ash, and lime, and highly-diverse stands dominated by beech, ash, lime, maple, and hornbeam. We investigated fine root biomass and necromass at 24 profiles per stand and analyzed species differences in fine root morphology by microscopic analysis. Fine root biomass ranged from 440 to 480 g m(-2) in the species-poor to species-rich stands, with 63-77% being concentrated in the upper 20 cm of the soil. In contradiction to our two hypotheses, the differences in tree species diversity affected neither stand fine root biomass nor vertical root distribution patterns. Fine root morphology showed marked distinctions between species, but these root morphological differences did not lead to significant differences in fine root surface area or root tip number on a stand area basis. Moreover, differences in species composition of the stands did not alter fine root morphology of the species. We conclude that 'below-ground overyielding' in terms of fine root biomass does not occur in the species-rich stands, which is most likely caused by the absence of significant spatial segregation of the root systems of these late-successional species.

  8. Estimating species trees from unrooted gene trees.

    Science.gov (United States)

    Liu, Liang; Yu, Lili

    2011-10-01

    In this study, we develop a distance method for inferring unrooted species trees from a collection of unrooted gene trees. The species tree is estimated by the neighbor joining (NJ) tree built from a distance matrix in which the distance between two species is defined as the average number of internodes between two species across gene trees, that is, average gene-tree internode distance. The distance method is named NJ(st) to distinguish it from the original NJ method. Under the coalescent model, we show that if gene trees are known or estimated correctly, the NJ(st) method is statistically consistent in estimating unrooted species trees. The simulation results suggest that NJ(st) and STAR (another coalescence-based method for inferring species trees) perform almost equally well in estimating topologies of species trees, whereas the Bayesian coalescence-based method, BEST, outperforms both NJ(st) and STAR. Unlike BEST and STAR, the NJ(st) method can take unrooted gene trees to infer species trees without using an outgroup. In addition, the NJ(st) method can handle missing data and is thus useful in phylogenomic studies in which data sets often contain missing loci for some individuals.

  9. Contributions to the phytocoenological study of pure european beech forests in Oraştie river basin (central-western Romania

    Directory of Open Access Journals (Sweden)

    Petru BURESCU

    2012-05-01

    Full Text Available În the current paper we present a phytocoenologic study of the phytocoenoses of the association Festuco drymejaeFagetum Morariu et al. 1968 (Syn.: Fagetum sylvaticae transylvaticum facies with Festuca drymeja I. Pop et al. 1974, found in the pure European beech forests of the Orăştie river basin, lying in the central-western part of Romania. The characterisation of the association under analysis as well as the presentation of the synthetic table have been done byselecting the most representative relevées of pure European beech forests belonging to the Orăştie river basin. The phytocoenoses of these beech forests were analysed in terms of physiognomy and floristic composition, life forms spectrum, floristic elements, and ecological indices.

  10. Contributions to the phytocoenological study of the beech forests of the Luzulo-Fagetum type in the Oraştie river basin (Central-Western Romania

    Directory of Open Access Journals (Sweden)

    Petru BURESCU

    2012-11-01

    Full Text Available n the current paper we present a phytocoenologic study of the phytocoenoses of the association Luzulo albidae-Fagetum sylvaticae Zólyomi 1955 (Syn.: Hieracio rotundati-Fagetum (Vida 1963 Täuber 1987, Dechampsio flexuosae-Fagetum Soó 1962, Luzulo-Fagetum silvaticae Beldie 1951 Morariu et al. 1968 identified in the acidophylous beech forests of the Orăştie river basin, situated in the central-western part of Romania. The characterisation of the association under analysis as well as the presentation of the synthetic table have been done by selecting the most representative relevées performed in the beech forests of the Luzulo-Fagetum type belonging to the Orăştie river. The phytocoenoses of these beech forests were analysed in terms of physiognomy and floristic composition, life forms spectrum, floristic elements, and ecological indices.

  11. Facilitative-competitive interactions in an old-growth forest: the importance of large-diameter trees as benefactors and stimulators for forest community assembly.

    Directory of Open Access Journals (Sweden)

    Andreas Fichtner

    Full Text Available The role of competition in tree communities is increasingly well understood, while little is known about the patterns and mechanisms of the interplay between above- and belowground competition in tree communities. This knowledge, however, is crucial for a better understanding of community dynamics and developing adaptive near-natural management strategies. We assessed neighbourhood interactions in an unmanaged old-growth European beech (Fagus sylvatica forest by quantifying variation in the intensity of above- (shading and belowground competition (crowding among dominant and co-dominant canopy beech trees during tree maturation. Shading had on average a much larger impact on radial growth than crowding and the sensitivity to changes in competitive conditions was lowest for crowding effects. We found that each mode of competition reduced the effect of the other. Increasing crowding reduced the negative effect of shading, and at high levels of shading, crowding actually had a facilitative effect and increased growth. Our study demonstrates that complementarity in above- and belowground processes enable F. sylvatica to alter resource acquisition strategies, thus optimising tree radial growth. As a result, competition seemed to become less important in stands with a high growing stock and tree communities with a long continuity of anthropogenic undisturbed population dynamics. We suggest that growth rates do not exclusively depend on the density of potential competitors at the intraspecific level, but on the conspecific aggregation of large-diameter trees and their functional role for regulating biotic filtering processes. This finding highlights the potential importance of the rarely examined relationship between the spatial aggregation pattern of large-diameter trees and the outcome of neighbourhood interactions, which may be central to community dynamics and the related forest ecosystem services.

  12. Amelioration of planting stress by soil amendment with a hydrogel–mycorrhiza mixture for early establishment of beech (Fagus sylvatica L.) seedlings

    OpenAIRE

    Beniwal, Rajender; Hooda, Mahinder; Polle, Andrea

    2011-01-01

    The mortality of nursery-grown beech (Fagus sylvatica L.) seedlings after out planting into the field is usually high.The goal of this study was to characterize the response of beech seedlings to planting stress and to test if soil amendment with a mixture of hydrogel and the ectomycorrhizal fungus Paxillus involutus could rescue the establishment of stressed plants. For this purpose, bare-rooted, dormant seedlings were exposed for 0, 2 and 6 h to air before planting.Water loss in response to...

  13. Major characteristics of mixed fir and beech virgin forests in the National park Biogradska Gora in Montenegro

    Directory of Open Access Journals (Sweden)

    Čurović Milić

    2011-01-01

    Full Text Available In order to manage forest ecosystems at a sufficiently high biodiversity level it is necessary to study the ecological, structural and production characteristics of virgin forests. The research was directed towards identifying the characteristics of mixed fir and beech forests (Abieti-Fagetum s. lat. in the area of the strict reserve of the National Park Biogradska Gora in Montenegro. Basic characteristics of these forests were researched in the process of definition of forest types. In this manner, it is for the first time that a realistic base for typological management of forests and forest ecosystems with similar ecological and structural characteristics was provided for the specific sites.

  14. Two years of continuous CO2 eddy-flux measurements over a Danish beech forest

    DEFF Research Database (Denmark)

    Pilegaard, K.; Hummelshøj, P.; Jensen, N.O.

    2001-01-01

    As part of the EUROFLUX network a long-term monitoring station for fluxes of CO2 and water vapour has been established in an 80-year old beech forest in Denmark. The station has been in continuous operation since June 1996 and will be so at least to the end of 2002. A primary goal of EUROFLUX...... summer of 1997 and an average soil and air temperature, respectively, 1.2 and 1.6 degreesC higher than the first year. The ecosystem photosynthetic assimilation was slightly higher during the second year, mainly caused by increased incoming radiation. (C) 2001 Elsevier Science B.V. All nights reserved....

  15. Changes in phenology and the influence on the carbon sequestration in a Danish beech forest over 20 years

    DEFF Research Database (Denmark)

    Pilegaard, Kim; Ibrom, Andreas

    Observations of carbon sequestration in a Danish beech forest over the last 20 years have shown a steady increase in NEE. Earlier studies (Pile- gaard et al. 2011) have shown, that about half of the increase can be attributed to an increase in the growing season length. The growing sea- son has...... been determined as the carbon uptake period (CUP); i.e. the period with net uptake, determined from flux data. Additionally, we have determined the period with leaves (LP) from the attenuation of light below the canopy. In this analysis we add information from a phenology camera with data from the last...

  16. Characterization of beech ectomycorrhizae formed by species of the Pachyphloeus-Amylascus lineage.

    Science.gov (United States)

    Erős-Honti, Zsolt; Jakucs, Erzsébet

    2009-06-01

    The hypogeous genus Pachyphloeus forms a common phylogenetic lineage with the epigeous Scabropezia and the hypogeous Amylascus, within the Pezizaceae (Ascomycota). Though the ectomycorrhiza- (EM) forming ability of this group was proposed previously, no detailed description has been published up to now, except for the characterization of EM related to P. virecens. During our several-year-long survey on the EM community of a beech forest reserve in Hungary, we found ten EM specimens belonging to the Pachyphloeus-Amylascus lineage. All of them share common morphological and anatomical characters. The densely ramifying whitish-yellow to light-brown mycorrhizal systems are pyramidal with short, stout ends. The EM surface is densely wooly with white or brown, curly hyphae. All mantle layers are pseudoparenchymatous angular, covered by a thick-walled hyphal network. Frequent emanating hyphae are densely septate without clamps. The EM can be sorted into three different morphotypes (Mt) according to their color, specific morphometric traits (cell-wall thickness, diameter of emanating hyphae, septal distance), and certain anatomical characters (structure of the surface net). Molecular identification was accomplished by the phylogenetic analysis of the ITS and LSU regions of the nrDNA, what proved that the sequences clustered into three clades corresponding to the three Mt. With the aid of fruitbody-derived sequences, obtained from GenBank, one of the Mt can be identified as Pachyphloeus melanoxanthus and another one as Pachyphloeus citrinus. The third Mt, together with another unidentified EM sequence of the GenBank, forms a distinct branch, which is a sister group to the Pachyphloeus-Scabropezia-Amylascus lineage. In addition to presenting the first detailed anatomical and molecular comparison of the EM related to P. melanoxanthus and P. citrinus, we call the attention to the need for further microscopical investigations amended by molecular taxonomical analyses.

  17. Specific features of electrical properties of porous biocarbons prepared from beech wood and wood artificial fiberboards

    Science.gov (United States)

    Popov, V. V.; Orlova, T. S.; Magarino, E. Enrique; Bautista, M. A.; Martínez-Fernández, J.

    2011-02-01

    This paper reports on comparative investigations of the structural and electrical properties of biomorphic carbons prepared from natural beech wood, as well as medium-density and high-density fiberboards, by means of carbonization at different temperatures T carb in the range 650-1000°C. It has been demonstrated using X-ray diffraction analysis that biocarbons prepared from medium-density and high-density fiberboards at all temperatures T carb contain a nanocrystalline graphite component, namely, three-dimensional crystallites 11-14 Å in size. An increase in the carbonization temperature T carb to 1000°C leads to the appearance of a noticeable fraction of two-dimensional graphene particles with the same sizes. The temperature dependences of the electrical resistivity ρ of the biomorphic carbons have been measured and analyzed in the temperature range 1.8-300 K. For all types of carbons under investigation, an increase in the carbonization temperature T carb from 600 to 900°C leads to a change in the electrical resistivity at T = 300 K by five or six orders of magnitude. The dependences ρ( T) for these materials are adequately described by the Mott law for the variable-range hopping conduction. It has been revealed that the temperature dependence of the electrical resistivity exhibits a hysteresis, which has been attributed to thermomechanical stresses in an inhomogeneous structure of the biocarbon prepared at a low carbonization temperature T carb. The crossover to the conductivity characteristic of disordered metal systems is observed at T carb ≳ 1000°C.

  18. Stoichiometric controls of nitrogen and phosphorus cycling in decomposing beech leaf litter.

    Science.gov (United States)

    Mooshammer, Maria; Wanek, Wolfgang; Schnecker, Jörg; Wild, Birgit; Leitner, Sonja; Hofhansl, Florian; Blöchl, Andreas; Hämmerle, Ieda; Frank, Alexander H; Fuchslueger, Lucia; Keiblinger, Katharina M; Zechmeister-Boltenstern, Sophie; Richter, Andreas

    2012-04-01

    Resource stoichiometry (C:N:P) is an important determinant of litter decomposition. However, the effect of elemental stoichiometry on the gross rates of microbial N and P cycling processes during litter decomposition is unknown. In a mesocosm experiment, beech (Fagus sylvatica L.) litter with natural differences in elemental stoichiometry (C:N:P) was incubated under constant environmental conditions. After three and six months, we measured various aspects of nitrogen and phosphorus cycling. We found that gross protein depolymerization, N mineralization (ammonification), and nitrification rates were negatively related to litter C:N. Rates of P mineralization were negatively correlated with litter C:P. The negative correlations with litter C:N were stronger for inorganic N cycling processes than for gross protein depolymerization, indicating that the effect of resource stoichiometry on intracellular processes was stronger than on processes catalyzed by extracellular enzymes. Consistent with this, extracellular protein depolymerization was mainly limited by substrate availability and less so by the amount of protease. Strong positive correlations between the interconnected N and P pools and the respective production and consumption processes pointed to feed-forward control of microbial litter N and P cycling. A negative relationship between litter C:N and phosphatase activity (and between litter C:P and protease activity) demonstrated that microbes tended to allocate carbon and nutrients in ample supply into the production of extracellular enzymes to mine for the nutrient that is more limiting. Overall, the study demonstrated a strong effect of litter stoichiometry (C:N:P) on gross processes of microbial N and P cycling in decomposing litter; mineralization of N and P were tightly coupled to assist in maintaining cellular homeostasis of litter microbial communities.

  19. Relaxed molecular clock provides evidence for long-distance dispersal of Nothofagus (southern beech.

    Directory of Open Access Journals (Sweden)

    Michael Knapp

    2005-01-01

    Full Text Available Nothofagus (southern beech, with an 80-million-year-old fossil record, has become iconic as a plant genus whose ancient Gondwanan relationships reach back into the Cretaceous era. Closely associated with Wegener's theory of "Kontinentaldrift", Nothofagus has been regarded as the "key genus in plant biogeography". This paradigm has the New Zealand species as passengers on a Moa's Ark that rafted away from other landmasses following the breakup of Gondwana. An alternative explanation for the current transoceanic distribution of species seems almost inconceivable given that Nothofagus seeds are generally thought to be poorly suited for dispersal across large distances or oceans. Here we test the Moa's Ark hypothesis using relaxed molecular clock methods in the analysis of a 7.2-kb fragment of the chloroplast genome. Our analyses provide the first unequivocal molecular clock evidence that, whilst some Nothofagus transoceanic distributions are consistent with vicariance, trans-Tasman Sea distributions can only be explained by long-distance dispersal. Thus, our analyses support the interpretation of an absence of Lophozonia and Fuscospora pollen types in the New Zealand Cretaceous fossil record as evidence for Tertiary dispersals of Nothofagus to New Zealand. Our findings contradict those from recent cladistic analyses of biogeographic data that have concluded transoceanic Nothofagus distributions can only be explained by vicariance events and subsequent extinction. They indicate that the biogeographic history of Nothofagus is more complex than envisaged under opposing polarised views expressed in the ongoing controversy over the relevance of dispersal and vicariance for explaining plant biodiversity. They provide motivation and justification for developing more complex hypotheses that seek to explain the origins of Southern Hemisphere biota.

  20. Urban tree growth modeling

    Science.gov (United States)

    E. Gregory McPherson; Paula J. Peper

    2012-01-01

    This paper describes three long-term tree growth studies conducted to evaluate tree performance because repeated measurements of the same trees produce critical data for growth model calibration and validation. Several empirical and process-based approaches to modeling tree growth are reviewed. Modeling is more advanced in the fields of forestry and...

  1. Keeping trees as assets

    Science.gov (United States)

    Kevin T. Smith

    2009-01-01

    Landscape trees have real value and contribute to making livable communities. Making the most of that value requires providing trees with the proper care and attention. As potentially large and long-lived organisms, trees benefit from commitment to regular care that respects the natural tree system. This system captures, transforms, and uses energy to survive, grow,...

  2. Size-specific tree mortality varies with neighbourhood crowding and disturbance in a Montane Nothofagus forest.

    Directory of Open Access Journals (Sweden)

    Jennifer M Hurst

    Full Text Available Tree mortality is a fundamental process governing forest dynamics, but understanding tree mortality patterns is challenging because large, long-term datasets are required. Describing size-specific mortality patterns can be especially difficult, due to few trees in larger size classes. We used permanent plot data from Nothofagus solandri var. cliffortioides (mountain beech forest on the eastern slopes of the Southern Alps, New Zealand, where the fates of trees on 250 plots of 0.04 ha were followed, to examine: (1 patterns of size-specific mortality over three consecutive periods spanning 30 years, each characterised by different disturbance, and (2 the strength and direction of neighbourhood crowding effects on size-specific mortality rates. We found that the size-specific mortality function was U-shaped over the 30-year period as well as within two shorter periods characterised by small-scale pinhole beetle and windthrow disturbance. During a third period, characterised by earthquake disturbance, tree mortality was less size dependent. Small trees (<20 cm in diameter were more likely to die, in all three periods, if surrounded by a high basal area of larger neighbours, suggesting that size-asymmetric competition for light was a major cause of mortality. In contrast, large trees (≥ 20 cm in diameter were more likely to die in the first period if they had few neighbours, indicating that positive crowding effects were sometimes important for survival of large trees. Overall our results suggest that temporal variability in size-specific mortality patterns, and positive interactions between large trees, may sometimes need to be incorporated into models of forest dynamics.

  3. Classification and regression trees

    CERN Document Server

    Breiman, Leo; Olshen, Richard A; Stone, Charles J

    1984-01-01

    The methodology used to construct tree structured rules is the focus of this monograph. Unlike many other statistical procedures, which moved from pencil and paper to calculators, this text's use of trees was unthinkable before computers. Both the practical and theoretical sides have been developed in the authors' study of tree methods. Classification and Regression Trees reflects these two sides, covering the use of trees as a data analysis method, and in a more mathematical framework, proving some of their fundamental properties.

  4. Tree number estimation with the use of VHR natural colour orthophotos over a heterogeneous landscape in northern Greece

    Science.gov (United States)

    Stournara, P.; Tsakiri-Strati, M.; Siachalou, S.; Doxani, G.; Mallinis, G.; Tsioukas, V.

    2015-04-01

    Spatial explicit knowledge regarding the quantity and the spatial distribution of forest parameters is crucial for sustainable forest management, as well as in fulfilling national reporting needs in the framework of international treaties (i.e. Kyoto Protocol, FAO, EFFIS etc). Especially, tree number which can be used for assessing forest tree density (tree number/ha), is among the most important and laboursome parameters to be measured in the field. The aim of this study is to estimate tree number based on the use of nationwide, freely available, very high spatial resolution orthophotos acquired from Greek National Cadastre and Mapping Agency during the 2007-2009 period. The study area is the University Forest of Taxiarchis, which is located in central Halkidiki, Northern Greece. The dominant species of the forest includes both broadleaves (oak, beech) and coniferous species (Black pine, Calabrian pine), which are found in both pure and mixed stands. Tree crown detection was tested on natural color orthophoto bands in several plots. The principal components and intensity-hue-saturation transformations were also applied in order to enhance tree detection accuracy. Local maxima technique was utilized for tree crown detection. Accuracy results were evaluated based on field plot data available from the official forest management plan of the area completed in 2011. Overall, the detection accuracy exceeded 50% which is deemed satisfactory considering also the heterogeneity of the Mediterranean landscape and the limited spectral resolution of the remote sensing data available.

  5. Effect of a long-term afforestation of pine in a beech domain in NE-Spain revealed by analytical pyrolysis (Py-GC/MS)

    Science.gov (United States)

    Girona García, Antonio; Badía-Villas, David; Tomás Jiménez-Morillo, Nicasio; Martí-Dalmau, Clara; González-Pérez, José Antonio

    2015-04-01

    The replacement of native beech forests (Fagus sylvatica) by Scots pine (Pinus sylvestris) afforestation may exert changes in soil properties, particularly in soil organic matter (SOM) [1]. It is known that the products generated by Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) pyrolysis of organic matter are related to their origin [2 and references therein]. Therefore this technique can be used to investigate said changes. In this work, Py-GC/MS is used to study changes in SOM quality surrogated to the effect of the centennial replacement of beech by Scots pine. The soils studied were two acid soil profiles developed on quartzites under a humid climate at an altitude of 1400-1500 masl from Moncayo (Iberian range, NE-Spain). For each soil profile three organic layers (litter: OL, fragmented litter OF and humified litter OH) and the mineral soil horizons (Ah, E, Bhs and C) were sampled. After 100 years since the pine afforestation, differences in the relative abundance of lipids released by pyrolysis were observed in the O-layers ranging from 3.82-7.20% in pine soils and 0.98-1.25% in beech soils. No differences were observed in mineral horizons with depth except for the C horizons where beech lipid content was much higher (21.25%) than in that under pine (1.07%). Both pine and beech soils show similar nitrogen compounds relative contents along the soil profile, increasing from OL to Ah (3.49-9.11% and 2.75-11.73% in beech and pine respectively) with a conspicuous reduction in the E horizon. It is remarkable the absence of nitrogen compounds in beech Bhs and C horizons. The relative content of aromatic compounds in O-layers show opposite trends for beech and pine; an enrichment in aromatic compounds is observed in beech OL layer (12.39%) decreasing to 4.11% in OH layer in contrast, whereas for pine O-layers the aromatic compounds relative abundance was higher in the OH (5.83%) than in the OL layer (2.8%). Mineral Ah and E horizons show similar values in

  6. Determination of incoming solar radiation in major tree species in Turkey.

    Science.gov (United States)

    Yilmaz, Osman Yalcin; Sevgi, Orhan; Koc, Ayhan

    2012-07-01

    Light requirements and spatial distribution of major forest tree species in Turkey hasn't been analyzed yet. Continuous surface solar radiation data, especially at mountainous-forested areas, are needed to put forward this relationship between forest tree species and solar radiation. To achieve this, GIS-based modeling of solar radiation is one of the methods used in rangelands to estimate continuous surface solar radiation. Therefore, mean monthly and annual total global solar radiation maps of whole Turkey were computed spatially using GRASS GIS software "r.sun" model under clear-sky (cloudless) conditions. 147498 pure forest stand point-based data were used in the study for calculating mean global solar radiation values of all the major forest tree species of Turkey. Beech had the lowest annual mean total global solar radiation value of 1654.87 kWh m(-2), whereas juniper had the highest value of 1928.89 kWh m(-2). The rank order of tree species according to the mean monthly and annual total global solar radiation values, using a confidence level of p Cedar trees ranked similarly.

  7. Non-reducing sugar levels in beech (Fagus sylvatica) seeds as related to withstanding desiccation and storage.

    Science.gov (United States)

    Pukacka, Stanisława; Ratajczak, Ewelina; Kalemba, Ewa

    2009-09-01

    Levels of sucrose and raffinose family oligosaccharides (RFOs) (raffinose and stachyose) were determined in beech (Fagus sylvatica L.) seeds during development, maturation, desiccation and storage. An increase in RFOs and a marked decrease in the S:(R+St) ratio (i.e. mass ratio of sucrose to the sum of RFOs) were observed at the time of desiccation tolerance (DT) acquisition by seeds. In seeds stored at -10 degrees C through 1, 4, 7, and 12 years, changes in sucrose, raffinose and stachyose levels and in alpha-galactosidase activity were noted. The S/R+St ratio and alpha-galactosidase activity significantly increased in seeds after 7 and 12 years of storage, when a marked decrease in viability, measured as germination capacity, was recorded. Germination capacity was found to be strongly correlated with sucrose content, the S:(R+St) ratio, and alpha-galactosidase activity. A strong positive correlation was found between germination capacity and stachyose content. The results clearly indicated that the composition of RFOs in beech seeds is closely related to DT acquisition and seed viability during storage.

  8. Fault tree handbook

    International Nuclear Information System (INIS)

    Haasl, D.F.; Roberts, N.H.; Vesely, W.E.; Goldberg, F.F.

    1981-01-01

    This handbook describes a methodology for reliability analysis of complex systems such as those which comprise the engineered safety features of nuclear power generating stations. After an initial overview of the available system analysis approaches, the handbook focuses on a description of the deductive method known as fault tree analysis. The following aspects of fault tree analysis are covered: basic concepts for fault tree analysis; basic elements of a fault tree; fault tree construction; probability, statistics, and Boolean algebra for the fault tree analyst; qualitative and quantitative fault tree evaluation techniques; and computer codes for fault tree evaluation. Also discussed are several example problems illustrating the basic concepts of fault tree construction and evaluation

  9. 77 FR 34339 - Yufeng Wei, a/k/a Annie Wei, 165 Beech Street, Belmont, MA 02378; Order Denying Export Privileges

    Science.gov (United States)

    2012-06-11

    ... DEPARTMENT OF COMMERCE Bureau of Industry and Security Yufeng Wei, a/k/a Annie Wei, 165 Beech... with the Under Secretary of Commerce for Industry and Security. The appeal must be filed within 45 days... of Commerce (18 U.S.C. 1001); and use of fraudulently obtained resident card (18 U.S.C. 1546(a)). Wei...

  10. Beech-mast crop evaluation in Kněhyně forest complex (Beskydy Mts. Czech Republic) as a food supply for granivorous rodents

    Czech Academy of Sciences Publication Activity Database

    Heroldová, Marta; Suchomel, J.; Purchart, L.; Čepelka, L.

    2013-01-01

    Roč. 6, č. 1 (2013), s. 27-32 ISSN 1803-2451 R&D Projects: GA MZe QH72075 Institutional support: RVO:68081766 Keywords : beech mountain forests * biomass of beechnuts harvest * diet supply for granivorous species Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection

  11. Lignin properties in topsoils of a beech/oak forest after 8 years of manipulated litter fall: relevance of altered input and oxidation of lignin

    NARCIS (Netherlands)

    Klotzbücher, T.; Strohmeier, S.; Kaiser, K.; Bowden, R.D.; Lajtha, K.; Ohm, H.; Kalbitz, K.

    2013-01-01

    Background and aims We studied the response of lignin oxidation in soils of a beech/oak forest to changes in litter fall. Additionally we considered possible factors in lignin oxidation, including altered (i) input of fresh organic matter and (ii) fungi-to-bacteria ratios. Methods The field-based

  12. Assessment of a relaxed eddy accumulation for measurements of fluxes of biogenic volatile organic compounds: Study over arable crops and a mature beech forest

    DEFF Research Database (Denmark)

    Gallagher, M.W.; Clayborough, R.; Beswick, K.M.

    2000-01-01

    A relaxed eddy accumulation (REA) system, based on the design by Beverland et al. (Journal of Geophysics Research 101 (D17) 22, 807-22, 815), for the measurement of biogenic VOC species was evaluated by intercomparison with an eddy correlation CO2 flux system over a mature deciduous beech canopy ...

  13. Inter-specific competition in mixed forests of Douglas-fir (Pseudotsuga menziesii) and common beech (Fagus sylvatica) under climate change – a model-based analysis

    NARCIS (Netherlands)

    Reyer, C.; Lasch, P.; Mohren, G.M.J.; Sterck, F.J.

    2010-01-01

    Mixed forests feature competitive interactions of the contributing species which influence their response to environmental change. • We analyzed climate change effects on the inter-specific competition in a managed Douglas-fir/beech mixed forest. • Therefore, we initialised the process-based forest

  14. Effects of litter quality and parent material on organic matter characteristics and N-dynamics in Luxembourg beech and hornbeam forests

    NARCIS (Netherlands)

    Kooijman, A.M.; Martinez-Hernandez, G.B.

    2009-01-01

    To test effects of litter quality and soil conditions on N-dynamics, we selected seven forests in Luxembourg dominated by beech (Fagus sylvatica, L.) and hornbeam (Carpinus betulus L.), and located on acid loam, decalcified marl or limestone, and measured organic matter characteristics, microbial C

  15. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jian-Ying; Ibragimov, Rashid

    2013-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting...... tree is isomorphic to T? We prove that in the general setting, CST is NP-complete, which implies that the tree edit distance considered here is also NP-hard, even when both input trees having diameters bounded by 10. We also show that, when the number of distinct stars is bounded by a constant k, CTS...

  16. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jiong; Ibragimov, Rashid

    2015-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting...... tree is isomorphic to T? We prove that in the general setting, CST is NP-complete, which implies that the tree edit distance considered here is also NP-hard, even when both input trees having diameters bounded by 10. We also show that, when the number of distinct stars is bounded by a constant k, CTS...

  17. Fault-Tree Compiler

    Science.gov (United States)

    Butler, Ricky W.; Boerschlein, David P.

    1993-01-01

    Fault-Tree Compiler (FTC) program, is software tool used to calculate probability of top event in fault tree. Gates of five different types allowed in fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N. High-level input language easy to understand and use. In addition, program supports hierarchical fault-tree definition feature, which simplifies tree-description process and reduces execution time. Set of programs created forming basis for reliability-analysis workstation: SURE, ASSIST, PAWS/STEM, and FTC fault-tree tool (LAR-14586). Written in PASCAL, ANSI-compliant C language, and FORTRAN 77. Other versions available upon request.

  18. Eddy-covariance methane flux measurements over a European beech forest

    Science.gov (United States)

    Gentsch, Lydia; Siebicke, Lukas; Knohl, Alexander

    2015-04-01

    The role of forests in global methane (CH4) turnover is currently not well constrained, partially because of the lack of spatially integrative forest-scale measurements of CH4 fluxes. Soil chamber measurements imply that temperate forests generally act as CH4 sinks. Upscaling of chamber observations to the forest scale is however problematic, if the upscaling is not constrained by concurrent 'top-down' measurements, such as of the eddy-covariance type, which provide sufficient integration of spatial variations and of further potential CH4 flux components within forest ecosystems. Ongoing development of laser absorption-based optical instruments, resulting in enhanced measurement stability, precision and sampling speed, has recently improved the prospects for meaningful eddy-covariance measurements at sites with presumably low CH4 fluxes, hence prone to reach the flux detection limit. At present, we are launching eddy-covariance CH4 measurements at a long-running ICOS flux tower site (Hainich National Park, Germany), located in a semi natural, unmanaged, beech dominated forest. Eddy-covariance measurements will be conducted with a laser spectrometer for parallel CH4, H2Ov and CO2 measurements (FGGA, Los Gatos Research, USA). Independent observations of the CO2 flux by the FGGA and a standard Infrared Gas Analyser (LI-7200, LI-COR, USA) will allow to evaluate data quality of measured CH4 fluxes. Here, we want to present first results with a focus on uncertainties of the calculated CH4 fluxes with regard to instrument precision, data processing and site conditions. In future, we plan to compare eddy-covariance flux estimates to side-by-side turbulent flux observations from a novel eddy accumulation system. Furthermore, soil CH4 fluxes will be measured with four automated chambers situated within the tower footprint. Based on a previous soil chamber study at the same site, we expect the Hainich forest site to act as a CH4 sink. However, we hypothesize that our

  19. Trees and highway safety.

    Science.gov (United States)

    2011-03-01

    To minimize the severity of run-off-road collisions of vehicles with trees, departments of transportation (DOTs) : commonly establish clear zones for trees and other fixed objects. Caltrans clear zone on freeways is 30 feet : minimum (40 feet pref...

  20. Seeds in the Organic Layers and Soil of Four Beech-Birch-Maple Stands

    Science.gov (United States)

    Raymond E. Graber; Donald F. Thompson

    1978-01-01

    Forest floor samples were collected in northern hardwood stands 5, 38, 95, and 200+ years old. The seeds contained in these samples were germinated in a greenhouse. Thirty-five species of herbs, shrubs, and trees were identified. The largest number of species, 23, were from the 5-year-old stand. The oldest stand had the fewest species, 17. Rubus and...

  1. Decision-Tree Program

    Science.gov (United States)

    Buntine, Wray

    1994-01-01

    IND computer program introduces Bayesian and Markov/maximum-likelihood (MML) methods and more-sophisticated methods of searching in growing trees. Produces more-accurate class-probability estimates important in applications like diagnosis. Provides range of features and styles with convenience for casual user, fine-tuning for advanced user or for those interested in research. Consists of four basic kinds of routines: data-manipulation, tree-generation, tree-testing, and tree-display. Written in C language.

  2. Multi-scale heterogeneity in the temporal origin of water taken up by trees water uptake inferred using stable isotopes

    Science.gov (United States)

    Allen, S. T.; Kirchner, J. W.; Braun, S.; Siegwolf, R. T.; Goldsmith, G. R.

    2017-12-01

    Xylem water isotopic composition can reveal how water moves through soil and is subsequently taken up by plants. By examining how xylem water isotopes vary across distinct climates and soils, we test how these site characteristics control critical-zone water movement and tree uptake. Xylem water was collected from over 900 trees at 191 sites across Switzerland during a 10-day period in mid-summer 2015. Sites contained oak, beech and/or spruce trees and ranged in elevation from 260 to 1870 m asl with mean annual precipitation from 700 to 2060 mm. Xylem water samples were analyzed for 2H and 18O using isotope ratio mass spectrometry. Patterns in the temporal origin of xylem water showed regional differences. For example, trees in the southern and alpine regions had xylem water isotopic signatures that more closely resembled summer precipitation. The isotopic spatial range observed for mid-summer xylem waters was similar to the seasonal range of precipitation; that is, mid-summer xylem water at some sites resembled summer precipitation, and at other sites resembled winter precipitation. Xylem water from spruces, oaks, and beeches at the same sites did not differ from each other, despite these species having different rooting habits. Across all sites and species, precipitation amount correlated positively with xylem δ18O. In higher-precipitation areas, summer rain apparently displaces or mixes with older (winter) stored waters, thus reducing the winter-water isotopic signal in xylem water. Alternatively, in areas with limited precipitation, xylem water more closely matched winter water, indicating greater use of older stored water. We conclude that regional variations in precipitation deficits determine variations in the turnover rate of plant-available soil water and storage.

  3. Uniform climate sensitivity in tree-ring stable isotopes across species and sites in a mid-latitude temperate forest.

    Science.gov (United States)

    Hartl-Meier, Claudia; Zang, Christian; Büntgen, Ulf; Esper, Jan; Rothe, Andreas; Göttlein, Axel; Dirnböck, Thomas; Treydte, Kerstin

    2015-01-01

    Tree-ring stable isotopes, providing insight into drought-induced eco-physiological mechanisms, are frequently used to reconstruct past changes in growing season temperature and precipitation. Their climatic response is, however, still not fully understood, particularly for data originating from non-extreme, mid-latitude environments with differing ecological conditions. Here, we assess the response of δ(13)C, δ(18)O and tree-ring width (TRW) from a temperate mountain forest in the Austrian pre-Alps to climate and specific drought events. Variations in stem growth and isotopic composition of Norway spruce, common beech and European larch from dry, medium and moist sites are compared with records of sunshine, temperature, moisture, precipitation and cloud cover. Results indicate uniform year-to-year variations in δ(13)C and δ(18)O across sites and species, but distinct differences in TRW according to habitat and species. While the climate sensitivity of TRW is overall weak, the δ(13)C and δ(18)O chronologies contain significant signals with a maximum sensitivity to cloud cover changes (r = -0.72 for δ(18)O). The coherent inter-annual isotopic variations are accompanied by substantial differences in the isotopic signatures with offsets up to ∼3‰ for δ(13)C, indicating species-specific physiological strategies and varying water-use efficiencies. During severe summer drought, beech and larch benefit from access to deeper and moist soils, allowing them to keep their stomata open. This strategy is accompanied by an increased water loss through transpiration, but simultaneously enables enhanced photosynthesis. Our findings indicate the potential of tree-ring stable isotopes from temperate forests to reconstruct changes in cloud cover, and to improve knowledge on basic physiological mechanisms of tree species growing in different habitats to cope with soil moisture deficits. © The Author 2014. Published by Oxford University Press. All rights reserved. For

  4. Winter Birch Trees

    Science.gov (United States)

    Sweeney, Debra; Rounds, Judy

    2011-01-01

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

  5. Total well dominated trees

    DEFF Research Database (Denmark)

    Finbow, Arthur; Frendrup, Allan; Vestergaard, Preben D.

    cardinality then G is a total well dominated graph. In this paper we study composition and decomposition of total well dominated trees. By a reversible process we prove that any total well dominated tree can both be reduced to and constructed from a family of three small trees....

  6. Macro tree transducers

    NARCIS (Netherlands)

    Engelfriet, Joost; Vogler, Heiko

    1985-01-01

    Macro tree transducers are a combination of top-down tree transducers and macro grammars. They serve as a model for syntax-directed semantics in which context information can be handled. In this paper the formal model of macro tree transducers is studied by investigating typical automata theoretical

  7. TreePics: visualizing trees with pictures

    Directory of Open Access Journals (Sweden)

    Nicolas Puillandre

    2017-09-01

    Full Text Available While many programs are available to edit phylogenetic trees, associating pictures with branch tips in an efficient and automatic way is not an available option. Here, we present TreePics, a standalone software that uses a web browser to visualize phylogenetic trees in Newick format and that associates pictures (typically, pictures of the voucher specimens to the tip of each branch. Pictures are visualized as thumbnails and can be enlarged by a mouse rollover. Further, several pictures can be selected and displayed in a separate window for visual comparison. TreePics works either online or in a full standalone version, where it can display trees with several thousands of pictures (depending on the memory available. We argue that TreePics can be particularly useful in a preliminary stage of research, such as to quickly detect conflicts between a DNA-based phylogenetic tree and morphological variation, that may be due to contamination that needs to be removed prior to final analyses, or the presence of species complexes.

  8. Simulating local adaptation to climate of forest trees with a Physio-Demo-Genetics model.

    Science.gov (United States)

    Oddou-Muratorio, Sylvie; Davi, Hendrik

    2014-04-01

    One challenge of evolutionary ecology is to predict the rate and mechanisms of population adaptation to environmental variations. The variations in most life history traits are shaped both by individual genotypic and by environmental variation. Forest trees exhibit high levels of genetic diversity, large population sizes, and gene flow, and they also show a high level of plasticity for life history traits. We developed a new Physio-Demo-Genetics model (denoted PDG) coupling (i) a physiological module simulating individual tree responses to the environment; (ii) a demographic module simulating tree survival, reproduction, and pollen and seed dispersal; and (iii) a quantitative genetics module controlling the heritability of key life history traits. We used this model to investigate the plastic and genetic components of the variations in the timing of budburst (TBB) along an elevational gradient of Fagus sylvatica (the European beech). We used a repeated 5 years climatic sequence to show that five generations of natural selection were sufficient to develop nonmonotonic genetic differentiation in the TBB along the local climatic gradient but also that plastic variation among different elevations and years was higher than genetic variation. PDG complements theoretical models and provides testable predictions to understand the adaptive potential of tree populations.

  9. Effects of acid rain and surfactant pollution on the foliar structure of some tree species

    International Nuclear Information System (INIS)

    Raddi, P.; Moricca, S.; Paoletti, E.

    1994-01-01

    For 10 years we have been studying the effects of acid rain and ABS (a surfactant always found in sea aerosols) on several tree species. Alterations of the leaf structure were considered as damage index. We tried to quantify the damage to the wax structure by scoring in accordance with a damage scale given by SEM observations and by computing a damage index that allowed for a comparison among tree provenances and within individuals of the same provenance or clone. We tested the response of several species: Norway spruce, silver fir, cypress, London plane, chestnut, walnut, Italian alder, tree of heaven, common maple, European white elm, manna ash, holm oak, European beech. The different species exhibited different levels of damage in relation to the type of treatment: when ABS was present, the damage was always more severe. In the broadleaved trees, the most frequent disturbances noted were: erosion of the epicuticular wax, alterations in the stomata, lesions, abscission and/or alternation of hairs. Damage from ABS treatments was compared to damge observed in coastal vegetation after strong sea winds. By comparing natural and induced damage, we were able to demonstrate that ABS is one of the possible causes of coastal vegetation decline and that ABS may also impact significantly on vegetation growing far away from the sea. (orig.)

  10. Effect of tree species and soil properties on nutrient immobilization in the forest floor

    DEFF Research Database (Denmark)

    Raulund-Rasmussen, Karsten; Vejre, Henrik

    1995-01-01

    To investigate the effect of tree species and soil properties on organic matter accumulation and associated nutrients, an area-based sampling of the forest floor was carried out in a 28 years old species trial including Norway spruce, Douglas fir, beech, and common oak at two sites, a poor...... and sandy soil, and a fertile loamy soil. The accumulation of C, N and P in the forest floor was significantly higher at the sandy site than at the loamy site under all species. At the loamy site, oak was characterized by lesser accumulation of C, N and P than the other species. Remarkably, the C...... of ammonium, nitrate and phosphate in the soil solution was much higher at the loamy site under all species showing a stronger microbial activity. It is therefore hypothesized that the differences in accumulation rates were, at least partly, caused by differences in the mineralization regimes. Strong root...

  11. The Investigation on Feasibility of Oriented Strand Boards to Parquet Production from Mixed Residual Veneer Popular and Beech

    Directory of Open Access Journals (Sweden)

    Saeid Kamrani

    2013-06-01

    Full Text Available The objective of this study was to investigate of feasibility of using residual veneer (popular and beechto manufacture oriented strand board (OSB parquet. Percentage of mixed residual veneer popular to beech was 40%to 60% respectly. In this study press time (6, 8 and 10 min and press temperature (170º, 180ºwere selected as variables, other factors being kept constant. Results indicated that increase of press temperature had no significant effect on modules of rupture, modules of elasticity and hardness but had significant effect on internal bonding, water absorption and thickness swelling. However results indicated that increase of press time had significant effect on total physical and mechanical properties of boards.

  12. Observation of dipropenyldisulfide and other organic sulfur compounds in the atmosphere of a beech forest with Allium ursinum ground cover

    Science.gov (United States)

    Puxbaum, H.; König, G.

    Dipropenyldisulfide, methylpropenyldisulfide, cis-propenylpropyldisulfide, diallylsulfide, dimethyldisulfide and 3-methylthiopropene were detected in the atmosphere of a beech forest with Allium ursinum (broad-leaved garlic) ground cover plants. Furthermore, it was shown that the Allium plants were the source of the organic sulfur compounds. The atmospheric concentrations of the organic sulfur observed on one day in May 1994 in a suburban forest in Vienna ranged from 0.3 to 7.8 ppb S with an average level of 2.9 ppb S. The atmospheric emission rate of organic sulfur species from A. ursinum determined with an enclosure box was the highest ever reported for terrestrial continental plants. The total organic sulfur flux on the average was at least 1 jug g-1h-1 (plant dry weight) or 60 gmgm-2 h-1 (per unit of ground area).

  13. Effects of surface inactivation, high temperature drying and preservative treatment on surface roughness and colour of alder and beech wood

    Science.gov (United States)

    Aydin, Ismail; Colakoglu, Gursel

    2005-10-01

    Although extensive research has been conducted in wood surface quality analysis, a unified approach to surface quality characterisation does not exist. Measurements of the variation in surface roughness and surface colour are used widely for the evaluation of wood surface quality. Colour is a basic visual feature for wood and wood-based products. Colour measurement is one of the quality control tests that should be carried out because the colour deviations are spotted easily by the consumers. On the other hand, a common problem faced by plywood manufacturers is panel delamination, for which a major cause is poor quality glue-bonds resulting from rough veneer. Rotary cut veneers with dimensions of 500 mm × 500 mm × 2 mm manufactured from alder ( Alnus glutinosa subsp. barbata) and beech ( Fagus orientalis Lipsky) logs were used as materials in this study. Veneer sheets were oven-dried in a veneer dryer at 110 °C (normal drying temperature) and 180 °C (high drying temperature) after peeling process. The surfaces of some veneers were then exposed at indoor laboratory conditions to obtain inactive wood surfaces for glue bonds, and some veneers were treated with borax, boric acid and ammonium acetate solutions. After these treatments, surface roughness and colour measurements were made on veneer surfaces. High temperature drying process caused a darkening on the surfaces of alder and beech veneers. Total colour change value (Δ E*) increased linear with increasing exposure time. Among the treatment solutions, ammonium acetate caused the biggest colour change while treatment with borax caused the lowest changes in Δ E* values. Considerable changes in surface roughness after preservative treatment did not occur on veneer surfaces. Generally, no clear changes were obtained or the values mean roughness profile ( Ra) decreased slightly in Ra values after the natural inactivation process.

  14. 24.000 ha de păduri primare de fag, propunerea României pentru Patrimoniul Mondial UNESCO [24000 ha of primary beech forests, the Romanian proposal in UNESCO World Heritage

    Directory of Open Access Journals (Sweden)

    Biriș I.-A.

    2016-08-01

    Full Text Available Under the coordination of The Ministry of Environment, Waters and Forests, about 24000 ha of primeval beech forests located in 8 natural protected area from the Romanian Carpathians were included for inscription into the World Heritage List to extend the „Primeval Beech Forests of the Carpathians and the Ancient Beech Forests of Germany” (1133bis. The extended World Heritage property is proposed to carry the joint new name: „Primeval Beech Forests of the Carpathians and Other Regions of Europe”. Supported by 13 European countries (Romania included, the nomination proposes to establish a transnational serial UNESCO property, with a surface of more that 95000 ha, that reunites the most representative and well preserved beech forests from the natural areal of this species in order to illustrate the ecological process of extension - that is in progress at present - of beech on the European continent. The process of choosing these canditate sites was thought for completing the existent sites and for providing arguments and reflecting better on the extension of species distribution at the level of Europe. At the end of January 2016, Austria, the coordinator country of the nomination process at the international level transmitted the common dossier for the nomination to the committee of evaluation of UNESCO World Heritage List.

  15. The valuative tree

    CERN Document Server

    Favre, Charles

    2004-01-01

    This volume is devoted to a beautiful object, called the valuative tree and designed as a powerful tool for the study of singularities in two complex dimensions. Its intricate yet manageable structure can be analyzed by both algebraic and geometric means. Many types of singularities, including those of curves, ideals, and plurisubharmonic functions, can be encoded in terms of positive measures on the valuative tree. The construction of these measures uses a natural tree Laplace operator of independent interest.

  16. A theory of game trees, based on solution trees

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); A. de Bruin (Arie); A. Plaat (Aske)

    1996-01-01

    textabstractIn this paper a complete theory of game tree algorithms is presented, entirely based upon the notion of a solution tree. Two types of solution trees are distinguished: max and min solution trees respectively. We show that most game tree algorithms construct a superposition of a max and a

  17. D2-tree

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Sioutas, Spyros; Pantazos, Kostas

    2015-01-01

    We present a new overlay, called the Deterministic Decentralized tree (D2-tree). The D2-tree compares favorably to other overlays for the following reasons: (a) it provides matching and better complexities, which are deterministic for the supported operations; (b) the management of nodes (peers......-balancing scheme of elements into nodes is deterministic and general enough to be applied to other hierarchical tree-based overlays. This load-balancing mechanism is based on an innovative lazy weight-balancing mechanism, which is interesting in its own right....

  18. Morocco - Fruit Tree Productivity

    Data.gov (United States)

    Millennium Challenge Corporation — Date Tree Irrigation Project: The specific objectives of this evaluation are threefold: - Performance evaluation of project activities, like the mid-term evaluation,...

  19. Validation of PROBA-V GEOV1 and MODIS C5 & C6 fAPAR Products in a Deciduous Beech Forest Site in Italy

    Czech Academy of Sciences Publication Activity Database

    Nestola, E.; Sanchez-Zapero, J.; Latorre, C.; Mazzenga, F.; Matteucci, G.; Calfapietra, Carlo; Camacho, F.

    2017-01-01

    Roč. 9, č. 2 (2017), č. článku 126. ISSN 2072-4292 Institutional support: RVO:86652079 Keywords : fAPAR * validation * PROBA-V GEOV1 * MODIS C5 * MODIS C6 * beech forest * up-scaling * GCOS requirements * in-situ comparison and evaluation Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 3.244, year: 2016

  20. Significance of tree roots for preferential infiltration in stagnic soils

    Science.gov (United States)

    Lange, B.; Lüescher, P.; Germann, P. F.

    2009-10-01

    It is generally recognized that roots have an effect on infiltration. In this study we analysed the relation between root length distributions from Norway spruce (Picea abies (L.) Karst), silver fir (Abies alba Miller), European beech (Fagus sylvatica L.) and preferential infiltration in stagnic soils in the northern Pre-Alps in Switzerland. We conducted irrigation experiments (1 m2) and recorded water content variations with time domain reflectometry (TDR). A rivulet approach was applied to characterise preferential infiltration. Roots were sampled down to a depth of 0.5 to 1 m at the same position where the TDR-probes had been inserted and digitally measured. The basic properties of preferential infiltration, film thickness of mobile water and the contact length between soil and mobile water in the horizontal plane are closely related to root densities. An increase in root density resulted in an increase in contact length, but a decrease in film thickness. We modelled water content waves based on root densities and identified a range of root densities that lead to a maximum volume flux density and infiltration capacity. These findings provide convincing evidence that tree roots in stagnic soils represent the pore system that carries preferential infiltration. Thus, the presence of roots should improve infiltration.

  1. Significance of tree roots for preferential infiltration in stagnic soils

    Directory of Open Access Journals (Sweden)

    B. Lange

    2009-10-01

    Full Text Available It is generally recognized that roots have an effect on infiltration. In this study we analysed the relation between root length distributions from Norway spruce (Picea abies (L. Karst, silver fir (Abies alba Miller, European beech (Fagus sylvatica L. and preferential infiltration in stagnic soils in the northern Pre-Alps in Switzerland. We conducted irrigation experiments (1 m2 and recorded water content variations with time domain reflectometry (TDR. A rivulet approach was applied to characterise preferential infiltration. Roots were sampled down to a depth of 0.5 to 1 m at the same position where the TDR-probes had been inserted and digitally measured. The basic properties of preferential infiltration, film thickness of mobile water and the contact length between soil and mobile water in the horizontal plane are closely related to root densities. An increase in root density resulted in an increase in contact length, but a decrease in film thickness. We modelled water content waves based on root densities and identified a range of root densities that lead to a maximum volume flux density and infiltration capacity. These findings provide convincing evidence that tree roots in stagnic soils represent the pore system that carries preferential infiltration. Thus, the presence of roots should improve infiltration.

  2. Adsorption of heavy metal ions by sawdust of deciduous trees.

    Science.gov (United States)

    Bozić, D; Stanković, V; Gorgievski, M; Bogdanović, G; Kovacević, R

    2009-11-15

    The adsorption of heavy metal ions from synthetic solutions was performed using sawdust of beech, linden and poplar trees. The adsorption depends on the process time, pH of the solution, type of ions, initial concentration of metals and the sawdust concentration in suspension. The kinetics of adsorption was relatively fast, reaching equilibrium for less than 20 min. The adsorption equilibrium follows Langmuir adsorption model. The ion exchange mechanism was confirmed assuming that the alkali-earth metals from the adsorbent are substituted by heavy metal ions and protons. On lowering the initial pH, the adsorption capacity decreased, achieving a zero value at a pH close to unity. The maximum adsorption capacity (7-8 mg g(-1) of sawdust) was achieved at a pH between 3.5 and 5 for all the studied kinds of sawdust. The initial concentration of the adsorbate and the concentration of sawdust strongly affect the process. No influence of particles size was evidenced. A degree of adsorption higher than 80% can be achieved for Cu(2+) ions but it is very low for Fe(2+) ions, not exceeding 10%.

  3. Adsorption of heavy metal ions by sawdust of deciduous trees

    International Nuclear Information System (INIS)

    Bozic, D.; Stankovic, V.; Gorgievski, M.; Bogdanovic, G.; Kovacevic, R.

    2009-01-01

    The adsorption of heavy metal ions from synthetic solutions was performed using sawdust of beech, linden and poplar trees. The adsorption depends on the process time, pH of the solution, type of ions, initial concentration of metals and the sawdust concentration in suspension. The kinetics of adsorption was relatively fast, reaching equilibrium for less than 20 min. The adsorption equilibrium follows Langmuir adsorption model. The ion exchange mechanism was confirmed assuming that the alkali-earth metals from the adsorbent are substituted by heavy metal ions and protons. On lowering the initial pH, the adsorption capacity decreased, achieving a zero value at a pH close to unity. The maximum adsorption capacity (7-8 mg g -1 of sawdust) was achieved at a pH between 3.5 and 5 for all the studied kinds of sawdust. The initial concentration of the adsorbate and the concentration of sawdust strongly affect the process. No influence of particles size was evidenced. A degree of adsorption higher than 80% can be achieved for Cu 2+ ions but it is very low for Fe 2+ ions, not exceeding 10%.

  4. Effect of altitude and tree species on {delta}{sup 34}S of deposited sulfur (Jezeri catchment, Czech Republic)

    Energy Technology Data Exchange (ETDEWEB)

    Groscheova, H.; Novak, M.; Havel, M.; Cerny, J. [Czech Geological Survey, Prague (Czech Republic)

    1998-07-01

    Precipitation total, SO{sub 4}{sup 2-} concentrations and {delta}{sup 34}S ratios were measured in bulk (open area) position, beech (with some birch and ash) and spruce throughfall at 17 locations in the heavily polluted mountain-slope Jezeri catchment (490-924 m asl) over a 12-month period. Stream water S was analyzed monthly at seven altitudes. The {delta}{sup 34}S ratios decreased in the order: bulk {gt} beech {gt} spruce {gt} stream (1995 annual means across all altitudes were 5.7, 5.1, 4.2 and 4.0{per_thousand}, respectively). The differences were caused by different intensities of scavenging of isotopically distinct pollution-derived SO{sub 2} by tree canopies. The {delta}{sup 34}S ratios of bulk deposition increased and {delta}{sup 34}S ratios of spruce throughfall decreased with increasing altitude. The elevational gradients in {delta}{sup 34}S ratios reflected the changing roles of local vs. distant air pollution sources along the slope. 15 refs., 5 figs.

  5. Tree-, stand- and site-specific controls on landscape-scale patterns of transpiration

    Science.gov (United States)

    Kathrin Hassler, Sibylle; Weiler, Markus; Blume, Theresa

    2018-01-01

    Transpiration is a key process in the hydrological cycle, and a sound understanding and quantification of transpiration and its spatial variability is essential for management decisions as well as for improving the parameterisation and evaluation of hydrological and soil-vegetation-atmosphere transfer models. For individual trees, transpiration is commonly estimated by measuring sap flow. Besides evaporative demand and water availability, tree-specific characteristics such as species, size or social status control sap flow amounts of individual trees. Within forest stands, properties such as species composition, basal area or stand density additionally affect sap flow, for example via competition mechanisms. Finally, sap flow patterns might also be influenced by landscape-scale characteristics such as geology and soils, slope position or aspect because they affect water and energy availability; however, little is known about the dynamic interplay of these controls.We studied the relative importance of various tree-, stand- and site-specific characteristics with multiple linear regression models to explain the variability of sap velocity measurements in 61 beech and oak trees, located at 24 sites across a 290 km2 catchment in Luxembourg. For each of 132 consecutive days of the growing season of 2014 we modelled the daily sap velocity and derived sap flow patterns of these 61 trees, and we determined the importance of the different controls.Results indicate that a combination of mainly tree- and site-specific factors controls sap velocity patterns in the landscape, namely tree species, tree diameter, geology and aspect. For sap flow we included only the stand- and site-specific predictors in the models to ensure variable independence. Of those, geology and aspect were most important. Compared to these predictors, spatial variability of atmospheric demand and soil moisture explains only a small fraction of the variability in the daily datasets. However, the temporal

  6. Creating 13C- and 15N-enriched tree leaf litter for decomposition experiments

    Science.gov (United States)

    Szlavecz, K. A.; Pitz, S.; Chang, C.; Bernard, M.

    2013-12-01

    Labeling plant material with heavy isotopes of carbon and nitrogen can produce a traceable nutrient signal that can be followed into the different trophic levels and decomposer food web. We treated 60 tree saplings with 13C-enriched CO2 gas and 15N-enriched ammonium nitrate over a three-month period to create dually-labeled plant material for future decomposition experiments. The trees included both early (Red maple, Sweetgum, Tulip poplar) and late (American beech, White oak) successional deciduous tree species, and a conifer, White pine. We constructed a 2.4 m × 2.4 m × 2.4 m environmental chamber that was climate-controlled using an air conditioning system. An Arduino microcontroller interfaced with a Vaisala GMP343 CO2 probe maintained a CO2 concentration between 500-520 ppm by controlling a solenoid valve on the CO2 tank regulator. The trees were placed into the chamber in August 2012 and remained until senescence unless they were lost to death or disease. Ammonium nitrate was added twice, in September and October. Leaf samples were collected prior to the start of the experiment and after senescence, whereas root samples were collected only in December. Samples were dried, ground and analyzed using an isotope ratio mass spectrometer. American beech and White oak had 40% mortality, and 34% of tulip poplar trees were removed because of powdery mildew overgrowth or death. Most tulip poplar trees exhibited a second leaf out following senescence in late September. Nearly 1 kg of litter was produced with tulip poplar representing over half of the total mass. Levels of enrichment varied greatly by species. Beech (-14.2‰) and White oak (-4.8‰) had low levels of enrichment in comparison to early successional species such as Sweetgum (41.7‰) and Tulip poplar (30.7‰ [first leaf fall] and 238.0‰ [second leaf fall]). Leaf enrichment with 15N followed a similar pattern, though it was achieved at a higher level with δ15N values varying from 271.6‰ to 1354.2

  7. Increased phytotoxic O3 dose accelerates autumn senescence in an O3-sensitive beech forest even under the present-level O3.

    Science.gov (United States)

    Kitao, Mitsutoshi; Yasuda, Yukio; Kominami, Yuji; Yamanoi, Katsumi; Komatsu, Masabumi; Miyama, Takafumi; Mizoguchi, Yasuko; Kitaoka, Satoshi; Yazaki, Kenichi; Tobita, Hiroyuki; Yoshimura, Kenichi; Koike, Takayoshi; Izuta, Takeshi

    2016-09-07

    Ground-level ozone (O3) concentrations are expected to increase over the 21(st) century, especially in East Asia. However, the impact of O3 has not been directly assessed at the forest level in this region. We performed O3 flux-based risk assessments of carbon sequestration capacity in an old cool temperate deciduous forest, consisting of O3-sensitive Japanese beech (Fagus crenata), and in a warm temperate deciduous and evergreen forest dominated by O3-tolerant Konara oak (Quercus serrata) based on long-term CO2 flux observations. On the basis of a practical approach for a continuous estimation of canopy-level stomatal conductance (Gs), higher phytotoxic ozone dose above a threshold of 0 uptake (POD0) with higher Gs was observed in the beech forest than that in the oak forest. Light-saturated gross primary production, as a measure of carbon sequestration capacity of forest ecosystem, declined earlier in the late growth season with increasing POD0, suggesting an earlier autumn senescence, especially in the O3-sensitive beech forest, but not in the O3-tolerant oak forest.

  8. Are trees long-lived?

    Science.gov (United States)

    Kevin T. Smith

    2009-01-01

    Trees and tree care can capture the best of people's motivations and intentions. Trees are living memorials that help communities heal at sites of national tragedy, such as Oklahoma City and the World Trade Center. We mark the places of important historical events by the trees that grew nearby even if the original tree, such as the Charter Oak in Connecticut or...

  9. Long-term growth trajectories in a changing climate: disentangling age from size effects in old Fagus trees from contrasting bioclimates

    Science.gov (United States)

    Di Filippo, Alfredo; Piovesan, Gianluca

    2016-04-01

    Understanding the drivers promoting exceptional longevity in trees and how their growth performances vary approaching maximum lifespan still represent intriguing challenges not only for tree biology, but also for modelling the long-term forest ecosystem functioning under a changing environment. Tree growth rate is expected to increase with increasing stem size, but higher risk of hydraulic failure and mortality can affect larger trees under increasingly dry conditions. In turn, very old trees are characterized by slow growth and smaller size, factors able to confer advantages against biotic and abiotic disturbances. Rising evidences that very old trees are negligibly affected by the progressive deterioration of physiological functions associated with age support the idea that size, not age, is the main constrain to tree lifespan, so that negative senescence has been proposed as a frequent phenomenon in trees. Additional empirical knowledge is needed to thoroughly assess how complex, uneven-aged old-growth forests cope under climate change in order to define their role in terrestrial carbon cycle. We used a tree-ring network of 8 European beech (Fagus sylvatica L.) old-growth forests containing several of the oldest crossdated broadleaf trees of the Northern Hemisphere (400-600 years old) to analyse how their growth rates vary along age/size development. We sampled advanced old-growth stands, where canopy tree mortality is naturally occurring, divided among contrasting bioclimatic conditions: eastern Alps and central Apennines (rainy vs. dry summer). To disentangle the long-term effects of size and age on long-term tree growth history, we reconstructed Basal Area Increment (BAI) along size (DBH) development, grouping growth trajectories in different age classes. On average, BAI increased continuously as stem size increased, regardless of bioclimatic region and age class. Old trees grew the slowest and kept increasing BAI trends. In turn, especially on the drier

  10. Effects of Drought and Rewetting on Growth and Gas Exchange of Minor European Broadleaved Tree Species

    Directory of Open Access Journals (Sweden)

    Jörg Kunz

    2016-10-01

    Full Text Available Widespread and economically important European tree species such as Norway spruce, Scots pine, and European beech are projected to be negatively affected by the increasing intensity and frequency of dry and hot conditions in a future climate. Hence, there is an increasing need to investigate the suitability of presumably more drought tolerant species to ensure future ecological stability, biodiversity, and productivity of forests. Based on their distribution patterns and climatic envelopes, the rare, minor broadleaved tree species Sorbus torminalis ((L. CRANTZ, S. domestica (L., Acer campestre (L., and A. platanoides (L. are assumed to be drought tolerant, however, there is only limited experimental basis to support that notion. This study aimed at quantifying growth and gas exchange of seedlings of these species during drought conditions, and their capacity to recover following drought. For that purpose, they were compared to the common companion species Quercus petraea ((MATTUSCHKA LIEBL. and Fagus sylvatica (L.. Here, potted seedlings of these species were exposed to water limitation followed by rewetting cycles in a greenhouse experiment. Photosynthesis and transpiration rates, stomatal conductance as well as root and shoot growth rates indicated a high drought resistance of A. campestre and A. platanoides. Sorbus domestica showed a marked ability to recover after drought stress. Therefore, we conclude that these minor tree species have the potential to enrich forests on drought-prone sites. Results from this pot experiment need to be complemented by field studies, in which the drought response of the species is not influenced by restrictions to root development.

  11. Comparison between AOT40 and ozone uptake in forest trees of different species, age and site conditions

    Science.gov (United States)

    Matyssek, R.; Wieser, G.; Nunn, A. J.; Kozovits, A. R.; Reiter, I. M.; Heerdt, C.; Winkler, J. B.; Baumgarten, M.; Häberle, K.-H.; Grams, T. E. E.; Werner, H.; Fabian, P.; Havranek, W. M.

    The current AOT40 concept for inferring risks in forest trees by ozone (O 3) injury is based on an accumulated external O 3 exposure rather than an internal O 3 dose or uptake rate. AOT40 assumes O 3 concentrations below 40 nl l -1 and night-time exposure to be negligible. Hence, this concept is rather inconsistent with observed forest conditions. In contrast, the flux concept of cumulative O 3 uptake (CU) into the leaves has the potential of reflecting a physiologically meaningful internal O 3 dose experienced by trees. In this paper, we relate AOT40 to cumulative O 3 uptake into European beech ( Fagus sylvatica), Norway spruce ( Picea abies), European larch ( Larix decidua) and cembran pine ( Pinus cembra) trees differing in size, age and site conditions. We demonstrate that the flux concept can be extended to the tree and the stand level, making use of sap flow measurements through tree trunks. Although in both seedlings and adult trees AOT40 may show some linearity in correlations with average CU, the latter varies, at given AOT40, by 25±11% within and between species. This is because O 3 flux is primarily influenced by stomatal aperture, the latter being affected by climate, canopy position, leaf and tree age while varying between species. In particular, if weighed by detoxification capacity, we suggest, therefore, O 3 uptake related air quality indices to be promoted towards ecologically meaningful standards in forest protection, overcoming the shortcomings of exposure concepts. As O 3 injury results from the balance between O 3 uptake and detoxification in the leaf mesophyll, we conclude the flux concept in combination with measures of biochemical defence to have the capacity for predicting tree response to O 3 stress.

  12. Decision Tree Phytoremediation

    Science.gov (United States)

    1999-12-01

    8 2.4 Irrigation, Agronomic Inputs, and...documents will provide the reader in-depth background on the science and engineering mechanisms of phytoremediation. Using the decision tree and the...ITRC – Phytoremediation Decision Tree December 1999 8 • Contaminant levels • Plant selection • Treatability • Irrigation, agronomic

  13. Tree biology and dendrochemistry

    Science.gov (United States)

    Kevin T. Smith; Walter C. Shortle

    1996-01-01

    Dendrochemistry, the interpretation of elemental analysis of dated tree rings, can provide a temporal record of environmental change. Using the dendrochemical record requires an understanding of tree biology. In this review, we pose four questions concerning assumptions that underlie recent dendrochemical research: 1) Does the chemical composition of the wood directly...

  14. Structural Equation Model Trees

    Science.gov (United States)

    Brandmaier, Andreas M.; von Oertzen, Timo; McArdle, John J.; Lindenberger, Ulman

    2013-01-01

    In the behavioral and social sciences, structural equation models (SEMs) have become widely accepted as a modeling tool for the relation between latent and observed variables. SEMs can be seen as a unification of several multivariate analysis techniques. SEM Trees combine the strengths of SEMs and the decision tree paradigm by building tree…

  15. Uncovering dynamic fault trees

    NARCIS (Netherlands)

    Junges, Sebastian; Guck, Dennis; Katoen, Joost P.; Stoelinga, Mariëlle Ida Antoinette

    Fault tree analysis is a widespread industry standard for assessing system reliability. Standard (static) fault trees model the failure behaviour of systems in dependence of their component failures. To overcome their limited expressive power, common dependability patterns, such as spare management,

  16. Matching Subsequences in Trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li

    2009-01-01

    Given two rooted, labeled trees P and T the tree path subsequence problem is to determine which paths in P are subsequences of which paths in T. Here a path begins at the root and ends at a leaf. In this paper we propose this problem as a useful query primitive for XML data, and provide new...

  17. Trees Are Terrific!

    Science.gov (United States)

    Braus, Judy, Ed.

    1992-01-01

    Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. Contents are organized into the following sections: (1) "What Makes a Tree a Tree?," including…

  18. Individual tree control

    Science.gov (United States)

    Harvey A. Holt

    1989-01-01

    Controlling individual unwanted trees in forest stands is a readily accepted method for improving the value of future harvests. The practice is especially important in mixed hardwood forests where species differ considerably in value and within species individual trees differ in quality. Individual stem control is a mechanical or chemical weeding operation that...

  19. Trees and Climate Change

    OpenAIRE

    Dettenmaier, Megan; Kuhns, Michael; Unger, Bethany; McAvoy, Darren

    2017-01-01

    This fact sheet describes the complex relationship between forests and climate change based on current research. It explains ways that trees can mitigate some of the risks associated with climate change. It details the impacts that forests are having on the changing climate and discuss specific ways that trees can be used to reduce or counter carbon emissions directly and indirectly.

  20. The tree BVOC index

    Science.gov (United States)

    J.R. Simpson; E.G. McPherson

    2011-01-01

    Urban trees can produce a number of benefits, among them improved air quality. Biogenic volatile organic compounds (BVOCs) emitted by some species are ozone precursors. Modifying future tree planting to favor lower-emitting species can reduce these emissions and aid air management districts in meeting federally mandated emissions reductions for these compounds. Changes...

  1. Environmental tritium in trees

    International Nuclear Information System (INIS)

    Brown, R.M.

    1979-01-01

    The distribution of environmental tritium in the free water and organically bound hydrogen of trees growing in the vicinity of the Chalk River Nuclear Laboratories (CRNL) has been studied. The regional dispersal of HTO in the atmosphere has been observed by surveying the tritium content of leaf moisture. Measurement of the distribution of organically bound tritium in the wood of tree ring sequences has given information on past concentrations of HTO taken up by trees growing in the CRNL Liquid Waste Disposal Area. For samples at background environmental levels, cellulose separation and analysis was done. The pattern of bomb tritium in precipitation of 1955-68 was observed to be preserved in the organically bound tritium of a tree ring sequence. Reactor tritium was discernible in a tree growing at a distance of 10 km from CRNL. These techniques provide convenient means of monitoring dispersal of HTO from nuclear facilities. (author)

  2. Coded Splitting Tree Protocols

    DEFF Research Database (Denmark)

    Sørensen, Jesper Hemming; Stefanovic, Cedomir; Popovski, Petar

    2013-01-01

    This paper presents a novel approach to multiple access control called coded splitting tree protocol. The approach builds on the known tree splitting protocols, code structure and successive interference cancellation (SIC). Several instances of the tree splitting protocol are initiated, each...... instance is terminated prematurely and subsequently iterated. The combined set of leaves from all the tree instances can then be viewed as a graph code, which is decodable using belief propagation. The main design problem is determining the order of splitting, which enables successful decoding as early...... as possible. Evaluations show that the proposed protocol provides considerable gains over the standard tree splitting protocol applying SIC. The improvement comes at the expense of an increased feedback and receiver complexity....

  3. Functional significance of tree species diversity and species identity on soil organic carbon, C/N ratio and pH in major European forest types

    DEFF Research Database (Denmark)

    Dawud, Seid Muhie

    supply (C/N ratio and pH). The studies were carried out in (1) forest floor and mineral soil to 20 cm depth across six different sites of major European forest types based on samples from one to five tree species mixtures along a latitudinal gradient from Spain to Finland, (2) soil profiles down to 40 cm...... within comparable environmental conditions in a Polish forest area, and (3) a trans-boundary approach in adjacent monoculture stands of Douglas-fir and beech at two common garden sites in Denmark. The thesis also included tree species diversity effects on fine root biomass, production and turnover under...... by the neighborhood approach. Root-related processes and inter-specific interactions could be the major driving factors in mature forests though there was no effect of diversity on fine root dynamics in young stands. The positive but generally additive diversity effects on soil C stock corresponded with previously...

  4. Current near-to-nature forest management effects on functional trait composition of saproxylic beetles in beech forests.

    Science.gov (United States)

    Gossner, Martin M; Lachat, Thibault; Brunet, Jörg; Isacsson, Gunnar; Bouget, Christophe; Brustel, Hervé; Brandl, Roland; Weisser, Wolfgang W; Müller, Jörg

    2013-06-01

    With the aim of wood production with negligible negative effects on biodiversity and ecosystem processes, a silvicultural practice of selective logging with natural regeneration has been implemented in European beech forests (Fagus sylvatica) during the last decades. Despite this near-to-nature strategy, species richness of various taxa is lower in these forests than in unmanaged forests. To develop guidelines to minimize the fundamental weaknesses in the current practice, we linked functional traits of saproxylic beetle species to ecosystem characteristics. We used continental-scale data from 8 European countries and regional-scale data from a large forest in southern Germany and forest-stand variables that represented a gradient of intensity of forest use to evaluate the effect of current near-to-nature management strategies on the functional diversity of saproxylic beetles. Forest-stand variables did not have a statistically significant effect on overall functional diversity, but they did significantly affect community mean and diversity of single functional traits. As the amount of dead wood increased the composition of assemblages shifted toward dominance of larger species and species preferring dead wood of large diameter and in advanced stages of decay. The mean amount of dead wood across plots in which most species occurred was from 20 to 60 m(3) /ha. Species occurring in plots with mean dead wood >60 m(3) /ha were consistently those inhabiting dead wood of large diameter and in advanced stages of decay. On the basis of our results, to make current wood-production practices in beech forests throughout Europe more conservation oriented (i.e., promoting biodiversity and ecosystem functioning), we recommend increasing the amount of dead wood to >20 m(3) /ha; not removing dead wood of large diameter (50 cm) and allowing more dead wood in advanced stages of decomposition to develop; and designating strict forest reserves, with their exceptionally high amounts of

  5. Language trees not equal gene trees.

    Science.gov (United States)

    Steele, James; Kandler, Anne

    2010-09-01

    Darwin saw similarities between the evolution of species and the evolution of languages, and it is now widely accepted that similarities between related languages can often be interpreted in terms of a bifurcating descent history ('phylogenesis'). Such interpretations are supported when the distributions of shared and unshared traits (for example, in terms of etymological roots for elements of basic vocabulary) are analysed using tree-building techniques and found to be well-explained by a phylogenetic model. In this article, we question the demographic assumption which is sometimes made when a tree-building approach has been taken to a set of cultures or languages, namely that the resulting tree is also representative of a bifurcating population history. Using historical census data relating to Gaelic- and English-speaking inhabitants of Sutherland (Highland Scotland), we have explored the dynamics of language death due to language shift, representing the extreme case of lack of congruence between the genetic and the culture-historical processes. Such cases highlight the important role of selective cultural migration (or shifting between branches) in determining the extinction rates of different languages on such trees.

  6. Isoprenoid emission response to changing light conditions of English oak, European beech and Norway spruce

    DEFF Research Database (Denmark)

    Van Meeningen, Ylva; Schurgers, Guy; Rinnan, Riikka

    2017-01-01

    Light is an important environmental factor controlling biogenic volatile organic compound (BVOC) emissions, but in natural conditions its impact is hard to separate from other influential factors such as temperature. We studied the light response of foliar BVOC emissions, photosynthesis...... be valid for a wider range of tree species. This information could be of importance when improving emission models and to further emphasize the discussion regarding light or temperature dependencies for individual compounds across species. Light is an important environmental factor controlling biogenic...... improving emission models and to further emphasize the discussion regarding light or temperature dependencies for individual compounds across species. Light is an important environmental factor controlling biogenic volatile organic compound (BVOC) emissions, but in natural conditions its impact is hard...

  7. Transcriptome survey of Patagonian southern beech Nothofagus nervosa (= N. Alpina: assembly, annotation and molecular marker discovery

    Directory of Open Access Journals (Sweden)

    Torales Susana L

    2012-07-01

    Full Text Available Abstract Background Nothofagus nervosa is one of the most emblematic native tree species of Patagonian temperate forests. Here, the shotgun RNA-sequencing (RNA-Seq of the transcriptome of N. nervosa, including de novo assembly, functional annotation, and in silico discovery of potential molecular markers to support population and associations genetic studies, are described. Results Pyrosequencing of a young leaf cDNA library generated a total of 111,814 high quality reads, with an average length of 447 bp. De novo assembly using Newbler resulted into 3,005 tentative isotigs (including alternative transcripts. The non-assembled sequences (singletons were clustered with CD-HIT-454 to identify natural and artificial duplicates from pyrosequencing reads, leading to 21,881 unique singletons. 15,497 out of 24,886 non-redundant sequences or unigenes, were successfully annotated against a plant protein database. A substantial number of simple sequence repeat markers (SSRs were discovered in the assembled and annotated sequences. More than 40% of the SSR sequences were inside ORF sequences. To confirm the validity of these predicted markers, a subset of 73 SSRs selected through functional annotation evidences were successfully amplified from six seedlings DNA samples, being 14 polymorphic. Conclusions This paper is the first report that shows a highly precise representation of the mRNAs diversity present in young leaves of a native South American tree, N. nervosa, as well as its in silico deduced putative functionality. The reported Nothofagus transcriptome sequences represent a unique resource for genetic studies and provide a tool to discover genes of interest and genetic markers that will greatly aid questions involving evolution, ecology, and conservation using genetic and genomic approaches in the genus.

  8. Patterns in δ15N in roots, stems, and leaves of sugar maple and American beech seedlings, saplings, and mature trees

    Science.gov (United States)

    L.H. Pardo; P. Semaoune; P.G. Schaberg; C. Eagar; M. Sebilo

    2013-01-01

    Stable isotopes of nitrogen (N) in plants are increasingly used to evaluate ecosystem N cycling patterns. A basic assumption in this research is that plant δ15N reflects the δ15N of the N source. Recent evidence suggests that plants may fractionate on uptake, transport, or transformation of N. If the...

  9. Inter- and intra-annual dynamics of height increment in young beech and spruce stands in relation to tree size and weather conditions

    Directory of Open Access Journals (Sweden)

    Konôpka Bohdan

    2014-03-01

    Full Text Available Počas rokov 2009-2013 sme sledovali sezónnu dynamiku výškového prírastku, ako aj celoročný výškový prírastok v bukových a smrekových mladinách rastúcich na totožnom stanovišti. Výsledky naznačili, že medziročné zmeny základných porastových charakteristík, a to najmä hustota porastu, boli výraznejšie v smrečine než v bučine. Omnoho vyššia stromová mortalita v smrečine sa vysvetlila nižšou intenzitou svetla pod korunovou vrstvou smrekov, resp. vyššou toleranciou buka na zatienenie. Veľké medzidruhové rozdiely sa zaznamenali v „načasovaní“ výškového prírastku. Konkrétne výškový prírastok bukov začal každoročne skôr ako výškový prírastok smrekov. Ďalej, terminál smrekov rástol dlhšie (približne 70 dní v porovnaní s bukmi (45 dní. Porovnanie priebehov výškových prírastkov vzhľadom na prostredie naznačilo, že principiálny vplyv mala globálna radiácia. V bučine bola maximálna intenzita výškového prírastku počas dní s maximálnou úrovňou globálnej radiácia, a to v rokoch 2009 a 2011, zároveň pokles intenzity sa objavil simultánne s poklesom globálnej radiácie počas roku 2012. V smrečine intenzita výškového prírastku predstavovala jednovrcholovú krivku - s najvyššou intenzitou prírastku v dňoch maximálnych hodnôt globálnej radiácie počas 2009 a 2012. Na druhej strane sa zaznamenal dvojvrcholový výskyt maxím intenzity výškového prírastku smrekov v 2010 a 2011. Tento jav súvisel s dočasným poklesom globálnej radiácie v týchto rokoch. Medzidruhové rozdiely v načasovaní výškového prírastku môžu mať relevanciu v prípade výskytu nepriaznivých poveternostných podmienok. Napríklad pri epizódach sucha v polovici vegetačného obdobia, keďže výškový prírastok je vtedy už ukončený pri bukoch avšak na smrekoch ešte prebieha

  10. Immission-load-related dynamics of S-SO42− in precipitation and in lysimetric solutions penetrating through beech ecosystems

    Directory of Open Access Journals (Sweden)

    Kukla Ján

    2017-12-01

    Full Text Available The paper presents the results of a 23-year study of sulphate sulphur dynamics in beech ecosystems exposed to different immission loads. The amounts of S-SO42− in precipitation water entering the ecosystems were: the Kremnické vrchy Mts, a clear-cut area 519 kg ha−1 (24.7 kg ha−1 per year, a beech forest 476 kg ha−1 (22.7 kg ha−1 per year; the Štiavnické vrchy Mts an open place 401 kg ha−1 (24.6 kg ha−1 per year, a beech forest 324 kg ha−1 (19.1 kg ha−1 per year. The average SO42− concentrations in lysimetric solutions penetrating through surface humus to a depth of Cambisol 10 and 25 cm were increased as follows: in the Kremnické vrchy Mts from 12.71 to 16.17 mg l−1 and in the Štiavnické vrchy Mts from 18.73 to 28.80 mg l−1. The S-SO4−2 amounts penetrating the individual soil layers in the Kremnické vrchy Mts were as follows: in case of surface humus on clear-cut area 459 kg ha−1 (20.9 kg ha−1 per year, in beech forest 433 kg ha−1 (19.7 kg ha−1 per year; below 10 cm organo-mineral layer of the mentioned plots penetrated 169–171 kg ha−1 (7.7–7.8 kg ha−1 per year, and below 25 cm mineral layer 155–255 kg ha−1 (7.1−11.6 kg ha−1 per year – a higher amount was found on clear-cut area with an episodic lateral flow of soil solutions. In beech forest of the Štiavnické vrchy Mts penetrated below surface humus 424 kg ha−1 S-SO42− (18.9 kg ha−1 per year, below 10 cm mineral layer 458 kg ha−1 S-SO42− (19.9 kg ha−1 per year, and below 25 cm mineral layer as much as 599 kg ha−1 S-SO42− (26.0 kg ha−1 per year. This fact was caused by frequent lateral flow of soil solutions. The results indicate that the assumption about lower immission load of the beech ecosystem in the Kremnické vrchy Mts is wrong, at least in the case of S-SO42−. The testing has revealed that the studied beech ecosystems differ very significantly in sulphur amounts penetrating under 0.10 m and 0.25 m. The

  11. Skewed Binary Search Trees

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Moruz, Gabriel

    2006-01-01

    It is well-known that to minimize the number of comparisons a binary search tree should be perfectly balanced. Previous work has shown that a dominating factor over the running time for a search is the number of cache faults performed, and that an appropriate memory layout of a binary search tree...... can reduce the number of cache faults by several hundred percent. Motivated by the fact that during a search branching to the left or right at a node does not necessarily have the same cost, e.g. because of branch prediction schemes, we in this paper study the class of skewed binary search trees....... For all nodes in a skewed binary search tree the ratio between the size of the left subtree and the size of the tree is a fixed constant (a ratio of 1/2 gives perfect balanced trees). In this paper we present an experimental study of various memory layouts of static skewed binary search trees, where each...

  12. Phylogenetic trees in bioinformatics

    Energy Technology Data Exchange (ETDEWEB)

    Burr, Tom L [Los Alamos National Laboratory

    2008-01-01

    Genetic data is often used to infer evolutionary relationships among a collection of viruses, bacteria, animal or plant species, or other operational taxonomic units (OTU). A phylogenetic tree depicts such relationships and provides a visual representation of the estimated branching order of the OTUs. Tree estimation is unique for several reasons, including: the types of data used to represent each OTU; the use ofprobabilistic nucleotide substitution models; the inference goals involving both tree topology and branch length, and the huge number of possible trees for a given sample of a very modest number of OTUs, which implies that fmding the best tree(s) to describe the genetic data for each OTU is computationally demanding. Bioinformatics is too large a field to review here. We focus on that aspect of bioinformatics that includes study of similarities in genetic data from multiple OTUs. Although research questions are diverse, a common underlying challenge is to estimate the evolutionary history of the OTUs. Therefore, this paper reviews the role of phylogenetic tree estimation in bioinformatics, available methods and software, and identifies areas for additional research and development.

  13. The effect of temperature and heating rate on char properties obtained from solar pyrolysis of beech wood.

    Science.gov (United States)

    Zeng, Kuo; Minh, Doan Pham; Gauthier, Daniel; Weiss-Hortala, Elsa; Nzihou, Ange; Flamant, Gilles

    2015-04-01

    Char samples were produced from pyrolysis in a lab-scale solar reactor. The pyrolysis of beech wood was carried out at temperatures ranging from 600 to 2000°C, with heating rates from 5 to 450°C/s. CHNS, scanning electron microscopy analysis, X-ray diffractometry, Brunauer-Emmett-Teller adsorption were employed to investigate the effect of temperature and heating rate on char composition and structure. The results indicated that char structure was more and more ordered with temperature increase and heating rate decrease (higher than 50°C/s). The surface area and pore volume firstly increased with temperature and reached maximum at 1200°C then reduced significantly at 2000°C. Besides, they firstly increased with heating rate and then decreased slightly at heating rate of 450°C/s when final temperature was no lower than 1200°C. Char reactivity measured by TGA analysis was found to correlate with the evolution of char surface area and pore volume with temperature and heating rate. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Effect of heat-treatment with raw cotton seed oil on decay resistance and dimensional stability of Beech (Fagus orientalis

    Directory of Open Access Journals (Sweden)

    مریم قربانی

    2015-05-01

    Full Text Available This research was conducted to determine the effect of heat-treatment with raw cotton seed oil on decay resistance and dimensional stability of beech according to EN113 and ASTM-D1037 standards respectively. The heat treatment with raw cotton seed oil was carried out in the cylinder at the temperatures of 130 and 170oC for 30 and 60 minutes. Oil uptake, density, volumetric swelling, water absorption and weight loss exposed to decay were measured. Oil uptake at 30 and 60 min were determined 10.5 and 13.3 Kg/cm3 respectively. Oil-heat treated samples at 30min and 130°C indicated the maximum density with 87.7% increase. According to results, oil-heat treatment improved water repellency and dimensional stability. Water absorption in 130°C and 60 minutes decreased 76% in comparison with control. Decay resistance of oil soaked samples for 60minutes was 80.2% more than control samples. Oil-heat treatment compared with oil treatment improved decay resistance, this effect was significant at 30 min. The temperature rise of oil–heat treatment at 30 minutes improved decay resistance, but the improvement under same level of temperature with increase time was not significant.

  15. Direct lactic acid production from beech wood by transgenic white-rot fungus Phanerochaete sordida YK-624.

    Science.gov (United States)

    Mori, Toshio; Kako, Hiroko; Sumiya, Tomoki; Kawagishi, Hirokazu; Hirai, Hirofumi

    2016-12-10

    A lactic acid (LA)-producing strain of the hyper-lignin-degrading fungus Phanerochaete sordida YK-624 with the lactate dehydrogenase-encoding gene from Bifidobacterium longum (Blldh) was constructed. When the endogenous pyruvate decarboxylase gene-knocked down and Blldh-expressing transformant was cultured with beech wood meal, the transformant was able to successively delignify and ferment the substrate. Supplementation of calcium carbonate into the culture medium, significantly increased the level of LA accumulation. Direct LA production (at 0.29g/l) from wood was confirmed, and additional inclusion of exogenous cellulase in this fermentation yielded significant further improvement in LA accumulation (up to 1.44g/l). This study provides the first report of direct production of LA by fermentation from woody biomass by a single microorganism, and indicates that transgenic white-rot fungi have a potential use for development of simple/easy applications for wood biorefinery. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Effect of activation on the porous structure and the strain and strength properties of beech wood biocarbon

    Science.gov (United States)

    Shpeizman, V. V.; Orlova, T. S.; Spitsyn, A. A.; Ponomarev, D. A.; Bogdanovich, N. I.; Martinez-Fernández, J.

    2017-01-01

    The effect of activation on the size, specific volume, and surface area of pores in a monolithic biomorphic material obtained by carbonization of beech wood is studied. It is shown that under optimal activation mode with a steam heated to 970°C, the total pore volume and surface, determined by adsorption curves, increased by 20 and 18 times, respectively. With the use of high-precision interferometric procedure, strain curves are obtained under uniaxial compression with a stepwise loading, and the strain rate is measured with a step of moving of 325 nm for activated and nonactivated samples. Despite an increase in porosity, the strength and maximum deformation of the samples do not decrease. The behavior of the strain rate jumps is analyzed in the micro- and nanometer range. It is shown that the maximum size of the micrometer jumps (4 μm) correlates well with the average size of the possible strain area in the samples (the average distance between the pores of small size), and the minimum dimensions of the strain jumps are close to the size of mesopores. Assessment of the strain change and its rate upon activation indicates that the effect of activation on the strain and strength characteristics is defined by nanometer defects, the most likely of which are microand mesopores.

  17. Clock Tree Power Analysis

    OpenAIRE

    Austbø, Knut

    2016-01-01

    The buffered clock tree structure is commonly used to distribute the clock signal to the memory elements in digital circuits. Since the clock signal is used as a temporal reference, it has to be distributed to the registers with decent timing characteristics and low skew. In order to achieve this, buffers and inverters are inserted in the clock tree, typically by a synthesis tool. The clock tree is a major contributor to the power consumption. This is a result of a combination of high swit...

  18. Damages to soil and tree species by cable-skidding in Caspian forests of Iran

    International Nuclear Information System (INIS)

    Tavankar, Farzam; Bonyad, Amir E.; Nikooy, Mehrdad; Picchio, Rodolfo; Venanzi, Rachele; Calienno, Luca

    2017-01-01

    Aim of study: The main aims of this study were to determine of damage level to residual stand and soil disturbance from mechanized selection logging. Area of study: Mixed beech stands in Caspian forests, northern Iran. Material and methods: Point-transect and systematic plot sampling were used for assessing damages to soil and trees, respectively. Main results: 89% of forest soil area was undisturbed or shallow disturbed, and 5.2% was deep disturbed. Soil bulk density of top 10 cm in the winching corridors, ruts and skid trails were increased 10.7%, 20.6% and 32.1% respectively than controlled area. Frequency of damages to regeneration and trees were 12% and 11.2%. The frequency of damages to regeneration was increased with increasing of their heights, but frequency of damages to trees was decreased with increasing of their diameter. The most type of damages was bole wounds in sizes of 100 to 200 cm2 within 1 m from the ground level, and deep wounds. The frequency of damages was different in tree species (p = 0.001). The mean size of bole wounds was 174 cm2, and the mean height of bole wounds was 70 cm from ground level. The intensity of wounds on trees bole were decreased with increasing of their heights from ground level (p = 0.02), while their sizes were increased (p = 0.001). Research highlights: Winching of logs was the main cause of damages to soil and residual stand. The detailed planning strategy will reduce damage to level which is acceptable and predictable.

  19. Damages to soil and tree species by cable-skidding in Caspian forests of Iran

    Energy Technology Data Exchange (ETDEWEB)

    Tavankar, Farzam; Bonyad, Amir E.; Nikooy, Mehrdad; Picchio, Rodolfo; Venanzi, Rachele; Calienno, Luca

    2017-11-01

    Aim of study: The main aims of this study were to determine of damage level to residual stand and soil disturbance from mechanized selection logging. Area of study: Mixed beech stands in Caspian forests, northern Iran. Material and methods: Point-transect and systematic plot sampling were used for assessing damages to soil and trees, respectively. Main results: 89% of forest soil area was undisturbed or shallow disturbed, and 5.2% was deep disturbed. Soil bulk density of top 10 cm in the winching corridors, ruts and skid trails were increased 10.7%, 20.6% and 32.1% respectively than controlled area. Frequency of damages to regeneration and trees were 12% and 11.2%. The frequency of damages to regeneration was increased with increasing of their heights, but frequency of damages to trees was decreased with increasing of their diameter. The most type of damages was bole wounds in sizes of 100 to 200 cm2 within 1 m from the ground level, and deep wounds. The frequency of damages was different in tree species (p = 0.001). The mean size of bole wounds was 174 cm2, and the mean height of bole wounds was 70 cm from ground level. The intensity of wounds on trees bole were decreased with increasing of their heights from ground level (p = 0.02), while their sizes were increased (p = 0.001). Research highlights: Winching of logs was the main cause of damages to soil and residual stand. The detailed planning strategy will reduce damage to level which is acceptable and predictable.

  20. Fine-root trait plasticity of beech (Fagus sylvatica) and spruce (Picea abies) forests on two contrasting soils

    NARCIS (Netherlands)

    Weemstra, M.; Sterck, F.J.; Visser, Eric J.W.; Kuyper, Thomas W.; Goudzwaard, L.; Mommer, L.

    2017-01-01

    Aim
    The fine roots of trees may show plastic responses to their resource environment. Several, contrasting hypotheses exist on this plasticity, but empirical evidence for these hypotheses is scattered. This study aims to enhance our understanding of tree root plasticity by examining

  1. Generalising tree traversals and tree transformations to DAGs

    DEFF Research Database (Denmark)

    Bahr, Patrick; Axelsson, Emil

    2017-01-01

    We present a recursion scheme based on attribute grammars that can be transparently applied to trees and acyclic graphs. Our recursion scheme allows the programmer to implement a tree traversal or a tree transformation and then apply it to compact graph representations of trees instead...

  2. Big trees, old trees, and growth factor tables

    Science.gov (United States)

    Kevin T. Smith

    2018-01-01

    The potential for a tree to reach a great size and to live a long life frequently captures the public's imagination. Sometimes the desire to know the age of an impressively large tree is simple curiosity. For others, the date-of-tree establishment can make a big diff erence for management, particularly for trees at historic sites or those mentioned in property...

  3. Hydrological properties of bark of selected forest tree species. Part 2: Interspecific variability of bark water storage capacity

    Directory of Open Access Journals (Sweden)

    Ilek Anna

    2017-06-01

    Full Text Available The subject of the present research is the water storage capacity of bark of seven forest tree species: Pinus sylvestris L., Larix decidua Mill., Abies alba Mill., Pinus sylvestris L., Quercus robur L., Betula pendula Ehrh. and Fagus sylvatica L. The aim of the research is to demonstrate differences in the formation of bark water storage capacity between species and to identify factors influencing the hydrological properties of bark. The maximum water storage capacity of bark was determined under laboratory conditions by performing a series of experiments simulating rainfall and by immersing bark samples in containers filled with water. After each single experiment, the bark samples were subjected to gravity filtration in a desiccator partially filled with water. The experiments lasted from 1084 to 1389 hours, depending on the bark sample. In all the studied species, bark sampled from the thinnest trees is characterized by the highest water storage capacity expressed in mm H2O · cm-3, while bark sampled from the thickest trees - by the lowest capacity. On the other hand, bark sampled from the thickest trees is characterized by the highest water storage capacity expressed in H2O · cm-2 whereas bark from the thinnest trees - by the lowest capacity. In most species tested, as the tree thickness and thus the bark thickness and the coefficient of development of the interception surface of bark increase, the sorption properties of the bark decrease with bark depth, and the main role in water retention is played by the outer bark surface. The bark of European beech is an exception because of the smallest degree of surface development and because the dominant process is the absorption of water. When examining the hydrological properties of bark and calculating its parameters, one needs to take into account the actual surface of the bark of trees. Disregarding the actual bark surface may lead to significant errors in the interpretation of research

  4. Structural Equation Model Trees

    Science.gov (United States)

    Brandmaier, Andreas M.; von Oertzen, Timo; McArdle, John J.; Lindenberger, Ulman

    2015-01-01

    In the behavioral and social sciences, structural equation models (SEMs) have become widely accepted as a modeling tool for the relation between latent and observed variables. SEMs can be seen as a unification of several multivariate analysis techniques. SEM Trees combine the strengths of SEMs and the decision tree paradigm by building tree structures that separate a data set recursively into subsets with significantly different parameter estimates in a SEM. SEM Trees provide means for finding covariates and covariate interactions that predict differences in structural parameters in observed as well as in latent space and facilitate theory-guided exploration of empirical data. We describe the methodology, discuss theoretical and practical implications, and demonstrate applications to a factor model and a linear growth curve model. PMID:22984789

  5. Tea Tree Oil

    Science.gov (United States)

    ... of Grants and Contracts General Award Mechanisms Small Business Research Grant Program (SBIR) Funding for: Natural Product ... cuts and wounds by the aboriginal people of Australia. Today, tea tree oil is often used externally ...

  6. A parallel buffer tree

    DEFF Research Database (Denmark)

    Sitchinava, Nodar; Zeh, Norbert

    2012-01-01

    We present the parallel buffer tree, a parallel external memory (PEM) data structure for batched search problems. This data structure is a non-trivial extension of Arge's sequential buffer tree to a private-cache multiprocessor environment and reduces the number of I/O operations by the number...... of available processor cores compared to its sequential counterpart, thereby taking full advantage of multicore parallelism. The parallel buffer tree is a search tree data structure that supports the batched parallel processing of a sequence of N insertions, deletions, membership queries, and range queries...... in the optimal OhOf(psortN + K/PB) parallel I/O complexity, where K is the size of the output reported in the process and psortN is the parallel I/O complexity of sorting N elements using P processors....

  7. NLCD 2001 - Tree Canopy

    Data.gov (United States)

    Minnesota Department of Natural Resources — The National Land Cover Database 2001 tree canopy layer for Minnesota (mapping zones 39-42, 50-51) was produced through a cooperative project conducted by the...

  8. Value tree analysis

    International Nuclear Information System (INIS)

    Keeney, R.; Renn, O.; Winterfeldt, D. von; Kotte, U.

    1985-01-01

    What are the targets and criteria on which national energy policy should be based. What priorities should be set, and how can different social interests be matched. To answer these questions, a new instrument of decision theory is presented which has been applied with good results to controversial political issues in the USA. The new technique is known under the name of value tree analysis. Members of important West German organisations (BDI, VDI, RWE, the Catholic and Protestant Church, Deutscher Naturschutzring, and ecological research institutions) were asked about the goals of their organisations. These goals were then ordered systematically and arranged in a hierarchical tree structure. The value trees of different groups can be combined into a catalogue of social criteria of acceptability and policy assessment. The authors describe the philosophy and methodology of value tree analysis and give an outline of its application in the development of a socially acceptable energy policy. (orig.) [de

  9. Adaptive Context Tree Weighting

    OpenAIRE

    O'Neill, Alexander; Hutter, Marcus; Shao, Wen; Sunehag, Peter

    2012-01-01

    We describe an adaptive context tree weighting (ACTW) algorithm, as an extension to the standard context tree weighting (CTW) algorithm. Unlike the standard CTW algorithm, which weights all observations equally regardless of the depth, ACTW gives increasing weight to more recent observations, aiming to improve performance in cases where the input sequence is from a non-stationary distribution. Data compression results show ACTW variants improving over CTW on merged files from standard compres...

  10. Type extension trees

    DEFF Research Database (Denmark)

    Jaeger, Manfred

    2006-01-01

    We introduce type extension trees as a formal representation language for complex combinatorial features of relational data. Based on a very simple syntax this language provides a unified framework for expressing features as diverse as embedded subgraphs on the one hand, and marginal counts...... of attribute values on the other. We show by various examples how many existing relational data mining techniques can be expressed as the problem of constructing a type extension tree and a discriminant function....

  11. Multiscale singularity trees

    DEFF Research Database (Denmark)

    Somchaipeng, Kerawit; Sporring, Jon; Johansen, Peter

    2007-01-01

    We propose MultiScale Singularity Trees (MSSTs) as a structure to represent images, and we propose an algorithm for image comparison based on comparing MSSTs. The algorithm is tested on 3 public image databases and compared to 2 state-of-theart methods. We conclude that the computational complexity...... of our algorithm only allows for the comparison of small trees, and that the results of our method are comparable with state-of-the-art using much fewer parameters for image representation....

  12. Tree Improvement Glossary

    DEFF Research Database (Denmark)

    Schmidt, Lars Holger

    Forest tree improvement encompasses a number of scientific and technical areas like floral-, reproductive- and micro-biology, genetics breeding methods and strategies, propagation, gene conservation, data analysis and statistics, each area with a comprehensive terminology. The terms selected...... for definition here are those most frequently used in tree improvement literature. Clonal propagation is included in the view of the great expansion of that field as a means of mass multiplication of improved material....

  13. Dependency Tree Annotation Software

    Science.gov (United States)

    2015-11-01

    between words. DTE supports the widely used Conference on Computational Natural Language Learning (CoNLL)-X format as well as several other file...formats, and it provides numerous options for customizing how dependency trees are displayed. Built entirely in Java , it can run on a wide range of...software application called Dependency Tree Editor (DTE) that can read files in Computational Natural Language Learning (CoNLL)-X format and use them

  14. Tree felling 2014

    CERN Multimedia

    2014-01-01

    With a view to creating new landscapes and making its population of trees safer and healthier, this winter CERN will complete the tree-felling campaign started in 2010.   Tree felling will take place between 15 and 22 November on the Swiss part of the Meyrin site. This work is being carried out above all for safety reasons. The trees to be cut down are at risk of falling as they are too old and too tall to withstand the wind. In addition, the roots of poplar trees are very powerful and spread widely, potentially damaging underground networks, pavements and roadways. Compensatory tree planting campaigns will take place in the future, subject to the availability of funding, with the aim of creating coherent landscapes while also respecting the functional constraints of the site. These matters are being considered in close collaboration with the Geneva nature and countryside directorate (Direction générale de la nature et du paysage, DGNP). GS-SE Group

  15. Anatomy of the Pythagoras' Tree

    Science.gov (United States)

    Teia, Luis

    2016-01-01

    The architecture of nature can be seen at play in a tree: no two are alike. The Pythagoras' tree behaves just as a "tree" in that the root plus the same movement repeated over and over again grows from a seed, to a plant, to a tree. In human life, this movement is termed cell division. With triples, this movement is a geometrical and…

  16. Attack Trees with Sequential Conjunction

    NARCIS (Netherlands)

    Jhawar, Ravi; Kordy, Barbara; Mauw, Sjouke; Radomirović, Sasa; Trujillo-Rasua, Rolando

    2015-01-01

    We provide the first formal foundation of SAND attack trees which are a popular extension of the well-known attack trees. The SAND at- tack tree formalism increases the expressivity of attack trees by intro- ducing the sequential conjunctive operator SAND. This operator enables the modeling of

  17. Towards the harmonization between National Forest Inventory and Forest Condition Monitoring. Consistency of plot allocation and effect of tree selection methods on sample statistics in Italy.

    Science.gov (United States)

    Gasparini, Patrizia; Di Cosmo, Lucio; Cenni, Enrico; Pompei, Enrico; Ferretti, Marco

    2013-07-01

    In the frame of a process aiming at harmonizing National Forest Inventory (NFI) and ICP Forests Level I Forest Condition Monitoring (FCM) in Italy, we investigated (a) the long-term consistency between FCM sample points (a subsample of the first NFI, 1985, NFI_1) and recent forest area estimates (after the second NFI, 2005, NFI_2) and (b) the effect of tree selection method (tree-based or plot-based) on sample composition and defoliation statistics. The two investigations were carried out on 261 and 252 FCM sites, respectively. Results show that some individual forest categories (larch and stone pine, Norway spruce, other coniferous, beech, temperate oaks and cork oak forests) are over-represented and others (hornbeam and hophornbeam, other deciduous broadleaved and holm oak forests) are under-represented in the FCM sample. This is probably due to a change in forest cover, which has increased by 1,559,200 ha from 1985 to 2005. In case of shift from a tree-based to a plot-based selection method, 3,130 (46.7%) of the original 6,703 sample trees will be abandoned, and 1,473 new trees will be selected. The balance between exclusion of former sample trees and inclusion of new ones will be particularly unfavourable for conifers (with only 16.4% of excluded trees replaced by new ones) and less for deciduous broadleaves (with 63.5% of excluded trees replaced). The total number of tree species surveyed will not be impacted, while the number of trees per species will, and the resulting (plot-based) sample composition will have a much larger frequency of deciduous broadleaved trees. The newly selected trees have-in general-smaller diameter at breast height (DBH) and defoliation scores. Given the larger rate of turnover, the deciduous broadleaved part of the sample will be more impacted. Our results suggest that both a revision of FCM network to account for forest area change and a plot-based approach to permit statistical inference and avoid bias in the tree sample

  18. Tree manipulation experiment

    Science.gov (United States)

    Nishina, K.; Takenaka, C.; Ishizuka, S.; Hashimoto, S.; Yagai, Y.

    2012-12-01

    Some forest operations such as thinning and harvesting management could cause changes in N cycling and N2O emission from soils, since thinning and harvesting managements are accompanied with changes in aboveground environments such as an increase of slash falling and solar radiation on the forest floor. However, a considerable uncertainty exists in effects of thinning and harvesting on N2O fluxes regarding changes in belowground environments by cutting trees. To focus on the effect of changes in belowground environments on the N2O emissions from soils, we conducted a tree manipulation experiment in Japanese cedar (Cryptomeria japonica) stand without soil compaction and slash falling near the chambers and measured N2O flux at 50 cm and 150 cm distances from the tree trunk (stump) before and after cutting. We targeted 5 trees for the manipulation and established the measurement chambers to the 4 directions around each targeted tree relative to upper slope (upper, left, right, lower positions). We evaluated the effect of logging on the emission by using hierarchical Bayesian model. HB model can evaluate the variability in observed data and their uncertainties in the estimation with various probability distributions. Moreover, the HB model can easily accommodate the non-linear relationship among the N2O emissions and the environmental factors, and explicitly take non-independent data (nested structure of data) for the estimation into account by using random effects in the model. Our results showed tree cutting stimulated N2O emission from soils, and also that the increase of N2O flux depended on the distance from the trunk (stump): the increase of N2O flux at 50 cm from the trunk (stump) was greater than that of 150 cm from the trunk. The posterior simulation of the HB model indicated that the stimulation of N2O emission by tree cut- ting could reach up to 200 cm in our experimental plot. By tree cutting, the estimated N2O emission at 0-40 cm from the trunk doubled

  19. Roost selection by barbastelle bats (Barbastella barbastellus, Chiroptera: Vespertilionidae in beech woodlands of central Italy

    Directory of Open Access Journals (Sweden)

    Danilo Russo

    2003-10-01

    Full Text Available The barbastelle bat, Barbastella barbastellus (Schreber, 1774 is a medium-sized, tree-dwelling vespertilionid classified as ?Endangered? in Italy; in western Europe it may be one of the rarest bat species. B. barbastellus shows roosting preferences that should be regarded as a key point in conservation protocols. We examined roost selection in a breeding population of B. barbastellus from the Abruzzo Lazio and Molise National Park (central Italy at three levels: woodland structure and management type; tree characteristics; and cavity characteristics. In 2001-2002, we fitted 31 adult B. barbastellus (29 lactating females, one pregnant female and one male with 0.48g radio-tags and tracked them to their roost-trees. The bats were tracked for 4.5 ± 3.7 days (range: 0-12 days. We located 33 roosts used by 25 subjects (1.8±1.2 roosts/bat, range 1-5. The bats switched roosts frequently: 13 bats used more than one tree over the study period. A chi-square analysis showed that the roosts were not distributed at random across woodland categories: unmanaged woodland was positively selected, whereas shelterwood-harvested woodland was used in proportion to its availability, and ?pastures+scattered trees? was avoided. Twenty out of 33 roost trees were dead Fagus sylvatica trees; conversely, living F. sylvatica dominated in a tree sample obtained at random; dead trees were used more than expected (Χ² test, P <0.001. Overall, roost trees were significantly taller and had a larger diameter at breast?s height and more cavities than random trees; they also had a lower percent canopy closure than random trees. To highlight which variables were actually associated with selection, we devised a logistic regression model. The full model was significant (P <0.001; removal of tree type and tree height affected the model significantly, but the other variables did not produce detectable effects. The

  20. Halfway encounters: meeting points of colonization routes among the southern beeches Nothofagus pumilio and N. antarctica.

    Science.gov (United States)

    Soliani, Carolina; Tsuda, Yoshiaki; Bagnoli, Francesca; Gallo, Leonardo A; Vendramin, Giovanni G; Marchelli, Paula

    2015-04-01

    The Patagonian region is characterized by a complex biogeographic history, with evidence of deep phylogeographic breaks shared among species. Of particular interest to conservation is the nature of colonization and settlement patterns after the last glacial period, including the detection of secondary contact between different lineages and/or hybridization among related species around phylogeographic breaks. Here we studied population demography and past hybridization of two widespread tree species endemic to South America, Nothofagus pumilio and N. antarctica. Using 8 nuclear microsatellites we genotyped 41 populations of both species. Genetic variation and structure across the geographic region were evaluated within and among species and the past demographic history of hybridization between the two species was inferred using Approximate Bayesian Computation (ABC). Northern and southern lineages were identified in each species, and Bayesian clustering revealed their convergence at mid latitudes (42°S). Spatial genetic structure (SGS) also indicated the existence of a genetic discontinuity at these latitudes, which is in agreement with previous data from maternal DNA markers. Several populations around 42-44°S presented high levels of genetic diversity with a decrease toward southern populations. Even though the species are clearly differentiated (G'ST=0.335), admixed gene pools were observed in both species. Two independent runs of ABC suggested that inter species admixture-like patterns occurred within the timescale of the Last Glacial Maximum (around 20,000 BP). We also provide evidences of recent and bi-directional hybridization/introgression between the two Nothofagus species and describe features of the populationś demography in the past. The settlement of a secondary contact zone in Nothofagus species around 42-44°S coincides with the phylogeographic breaks and hotspots of genetic diversity found in other plant and animal species in Patagonia

  1. Effect on a long-term afforestation of pine in a beech domain in NE-Spain as reflected in soil C and N isotopic signature

    Science.gov (United States)

    Girona García, Antonio; Badía-Villas, David; González-Pérez, José Antonio; Tomás Jiménez-Morillo, Nicasio; Martí-Dalmau, Clara

    2015-04-01

    The replacement of native beech forests (Fagus sylvatica) by Scots pine (Pinus sylvestris) afforestation may exert changes in soil properties, particularly in soil organic matter (SOM) (Carceller and Vallejo, 1996). Stable isotopic signatures of light elements (d13C, d15N) in soils and plants are valuable proxies for the identification of biogeochemical processes and their rates in the pedosphere (Andreeva et al., 2013 and refs therein). In this work the C and N stable isotopic analysis is used as a proxy to detect changes in SOM surrogated to the effect of centennial replacement of beech by the Scots pinewood. Two acid soil profiles, developed on quartzites under a humid climate at an altitude of 1400-1500 masl, have been sampled in Moncayo (Iberian range, NE-Spain). For each soil profile three O-layers (litter: OL, fragmented litter OF and humified litter OH) and mineral soil horizons (Ah, E, Bhs and C) were sampled. Content and bulk isotopic signature of light elements (C and N) were analysed in a Flash 2000 elemental micro-analyser coupled via a ConFlo IV interface to a Delta V Advantage isotope ratio mass spectrometer (IRMS) (Thermo Scientific, Bremen, Germany). Isotopic ratios are reported as parts per thousand deviations from appropriate standards. The standard deviations of d13C and d15N were typically less than ± 0.05 per thousand, ± 0.2 per thousand, respectively. After 100 years since the pine afforestation, no differences on C content were observed in the O-layers, ranging from 30-47% in pine soils and 37-47 % in beech soils. Similarly, no differences on N content were observed in the O-layers, ranging from 1.24-1.86 % in pine soils and 1.70-1.71 % in beech soils. C and N contents decrease progressively in depth with the exception of E-horizons where the lowest C and N content values were found. C/N ratio is higher in pine soil (20.7-38.1) than in beech O soil horizons (21.8-27.5), showing similar behavior with soil depth. Pine biomass was slightly

  2. Native lignin for bonding fiber boards - evaluation of bonding mechanisms in boards made from laccase-treated fibers of beech (Fagus sylvatica)

    DEFF Research Database (Denmark)

    Felby, Claus; Thygesen, Lisbeth Garbrecht; Sanadi, Anand

    2004-01-01

    The auto-adhesion of beech wood (Fagus sylvatica) fibers can be enhanced by a pretreatment of the fibers with a phenol oxidase enzyme. The mechanism of enzymatic catalyzed bonding is linked to the generation of stable radicals in lignin by oxidation. Fiberboards made from laccase-treated fibers...... indicate that lignin extractives are precipitated on the fiber surfaces. The improved bonding may be related to several factors, linked to a more lignin rich fiber surface, such as surface molecular entanglements and covalent bonding between fibers through cross-linking of radicals. (C) 2004 Published...

  3. Desiccation and Mortality Dynamics in Seedlings of Different European Beech (Fagus sylvatica L.) Populations under Extreme Drought Conditions

    DEFF Research Database (Denmark)

    Bolte, Andreas; Czajkowski, Tomasz; Cocozza, Claudia

    2016-01-01

    beech to climate change in its native range. In a common garden experiment with one-year-old seedlings originating from central and marginal origins in six European countries (Denmark, Germany, France, Romania, Bosnia-Herzegovina, and Spain), we applied extreme drought stress and observed desiccation...... and mortality processes among the different populations and related them to plant water status (predawn water potential, 9PD) and soil hydraulic traits. For the lethal drought assessment, we used a critical threshold of soil water availability that is reached when 50% mortality in seedling populations occurs...

  4. Contributions to the phytocoenological study of pure european beech forests in Oraştie river basin (central-western Romania)

    OpenAIRE

    Petru BURESCU; Valeriu Ioan VINŢAN

    2012-01-01

    În the current paper we present a phytocoenologic study of the phytocoenoses of the association Festuco drymejaeFagetum Morariu et al. 1968 (Syn.: Fagetum sylvaticae transylvaticum facies with Festuca drymeja I. Pop et al. 1974), found in the pure European beech forests of the Orăştie river basin, lying in the central-western part of Romania. The characterisation of the association under analysis as well as the presentation of the synthetic table have been done byselecting the most representa...

  5. Contributions to the phytocoenological study of the beech forests of the Luzulo-Fagetum type in the Oraştie river basin (Central-Western Romania)

    OpenAIRE

    Petru BURESCU; Valeriu Ioan VINTAN

    2012-01-01

    n the current paper we present a phytocoenologic study of the phytocoenoses of the association Luzulo albidae-Fagetum sylvaticae Zólyomi 1955 (Syn.: Hieracio rotundati-Fagetum (Vida 1963) Täuber 1987, Dechampsio flexuosae-Fagetum Soó 1962, Luzulo-Fagetum silvaticae Beldie 1951) Morariu et al. 1968) identified in the acidophylous beech forests of the Orăştie river basin, situated in the central-western part of Romania. The characterisation of the association under analysis as well as the pre...

  6. Particulate emissions from the combustion of birch, beech, and spruce logs cause different cytotoxic responses in A549 cells.

    Science.gov (United States)

    Kasurinen, Stefanie; Jalava, Pasi I; Happo, Mikko S; Sippula, Olli; Uski, Oskari; Koponen, Hanna; Orasche, Jürgen; Zimmermann, Ralf; Jokiniemi, Jorma; Hirvonen, Maija-Riitta

    2017-05-01

    According to the World Health Organization particulate emissions from the combustion of solid fuels caused more than 110,000 premature deaths worldwide in 2010. Log wood combustion is the most prevalent form of residential biomass heating in developed countries, but it is unknown how the type of wood logs used in furnaces influences the chemical composition of the particulate emissions and their toxicological potential. We burned logs of birch, beech and spruce, which are used commonly as firewood in Central and Northern Europe in a modern masonry heater, and compared them to the particulate emissions from an automated pellet boiler fired with softwood pellets. We determined the chemical composition (elements, ions, and carbonaceous compounds) of the particulate emissions with a diameter of less than 1 µm and tested their cytotoxicity, genotoxicity, inflammatory potential, and ability to induce oxidative stress in a human lung epithelial cell line. The chemical composition of the samples differed significantly, especially with regard to the carbonaceous and metal contents. Also the toxic effects in our tested endpoints varied considerably between each of the three log wood combustion samples, as well as between the log wood combustion samples and the pellet combustion sample. The difference in the toxicological potential of the samples in the various endpoints indicates the involvement of different pathways of toxicity depending on the chemical composition. All three emission samples from the log wood combustions were considerably more toxic in all endpoints than the emissions from the pellet combustion. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1487-1499, 2017. © 2016 Wiley Periodicals, Inc.

  7. The impact of forest roads on understory plant diversity in temperate hornbeam-beech forests of Northern Iran.

    Science.gov (United States)

    Deljouei, Azade; Abdi, Ehsan; Marcantonio, Matteo; Majnounian, Baris; Amici, Valerio; Sohrabi, Hormoz

    2017-08-01

    Forest roads alter the biotic and abiotic components of ecosystems, modifying temperature, humidity, wind speed, and light availability that, in turn, cause changes in plant community composition and diversity. We aim at investigating and comparing the diversity of herbaceous species along main and secondary forest roads in a temperate-managed hornbeam-beech forest, north of Iran. Sixteen transects along main and secondary forest roads were established (eight transects along main roads and eight along secondary roads). To eliminate the effect of forest type, all transects were located in Carpinetum-Fagetum forests, the dominant forest type in the study area. The total length of each transect was 200 m (100 m toward up slope and 100 m toward down slope), and plots were established along it at different distances from road edge. The diversity of herbaceous plant species was calculated in each plot using Shannon-Wiener index, species richness, and Pielou's index. The results showed that diversity index decreased when distance from road edge increases. This decreasing trend continued up to 60 m from forest road margin, and after this threshold, the index slightly increased. Depending on the type of road (main or secondary) as well as cut or fill slopes, the area showing a statistical different plant composition and diversity measured through Shannon-Wiener, species richness, and Pielou's index is up to 10 m. The length depth of the road edge effect found in main and secondary forest roads was small, but it could have cumulative effects on forest microclimate and forest-associated biota at the island scale. Forest managers should account for the effect of road buildings on plant communities.

  8. Estimation of canopy attributes in beech forests using true colour digital images from a small fixed-wing UAV

    Science.gov (United States)

    Chianucci, Francesco; Disperati, Leonardo; Guzzi, Donatella; Bianchini, Daniele; Nardino, Vanni; Lastri, Cinzia; Rindinella, Andrea; Corona, Piermaria

    2016-05-01

    Accurate estimates of forest canopy are essential for the characterization of forest ecosystems. Remotely-sensed techniques provide a unique way to obtain estimates over spatially extensive areas, but their application is limited by the spectral and temporal resolution available from these systems, which is often not suited to meet regional or local objectives. The use of unmanned aerial vehicles (UAV) as remote sensing platforms has recently gained increasing attention, but their applications in forestry are still at an experimental stage. In this study we described a methodology to obtain rapid and reliable estimates of forest canopy from a small UAV equipped with a commercial RGB camera. The red, green and blue digital numbers were converted to the green leaf algorithm (GLA) and to the CIE L*a*b* colour space to obtain estimates of canopy cover, foliage clumping and leaf area index (L) from aerial images. Canopy attributes were compared with in situ estimates obtained from two digital canopy photographic techniques (cover and fisheye photography). The method was tested in beech forests. UAV images accurately quantified canopy cover even in very dense stand conditions, despite a tendency to not detecting small within-crown gaps in aerial images, leading to a measurement of a quantity much closer to crown cover estimated from in situ cover photography. Estimates of L from UAV images significantly agreed with that obtained from fisheye images, but the accuracy of UAV estimates is influenced by the appropriate assumption of leaf angle distribution. We concluded that true colour UAV images can be effectively used to obtain rapid, cheap and meaningful estimates of forest canopy attributes at medium-large scales. UAV can combine the advantage of high resolution imagery with quick turnaround series, being therefore suitable for routine forest stand monitoring and real-time applications.

  9. Cytotoxic and genotoxic responses of human lung cells to combustion smoke particles of Miscanthus straw, softwood and beech wood chips

    Science.gov (United States)

    Arif, Ali Talib; Maschowski, Christoph; Garra, Patxi; Garcia-Käufer, Manuel; Petithory, Tatiana; Trouvé, Gwenaëlle; Dieterlen, Alain; Mersch-Sundermann, Volker; Khanaqa, Polla; Nazarenko, Irina; Gminski, Richard; Gieré, Reto

    2017-08-01

    Inhalation of particulate matter (PM) from residential biomass combustion is epidemiologically associated with cardiovascular and pulmonary diseases. This study investigates PM0.4-1 emissions from combustion of commercial Miscanthus straw (MS), softwood chips (SWC) and beech wood chips (BWC) in a domestic-scale boiler (40 kW). The PM0.4-1 emitted during combustion of the MS, SWC and BWC were characterized by ICP-MS/OES, XRD, SEM, TEM, and DLS. Cytotoxicity and genotoxicity in human alveolar epithelial A549 and human bronchial epithelial BEAS-2B cells were assessed by the WST-1 assay and the DNA-Alkaline Unwinding Assay (DAUA). PM0.4-1 uptake/translocation in cells was investigated with a new method developed using a confocal reflection microscope. SWC and BWC had a inherently higher residual water content than MS. The PM0.4-1 emitted during combustion of SWC and BWC exhibited higher levels of Polycyclic Aromatic Hydrocarbons (PAHs), a greater variety of mineral species and a higher heavy metal content than PM0.4-1 from MS combustion. Exposure to PM0.4-1 from combustion of SWC and BWC induced cytotoxic and genotoxic effects in human alveolar and bronchial cells, whereby the strongest effect was observed for BWC and was comparable to that caused by diesel PM (SRM 2 975), In contrast, PM0.4-1 from MS combustion did not induce cellular responses in the studied lung cells. A high PAH content in PM emissions seems to be a reliable chemical marker of both combustion efficiency and particle toxicity. Residual biomass water content strongly affects particulate emissions and their toxic potential. Therefore, to minimize the harmful effects of fine PM on health, improvement of combustion efficiency (aiming to reduce the presence of incomplete combustion products bound to PM) and application of fly ash capture technology, as well as use of novel biomass fuels like Miscanthus straw is recommended.

  10. Steiner trees in industry

    CERN Document Server

    Du, Ding-Zhu

    2001-01-01

    This book is a collection of articles studying various Steiner tree prob­ lems with applications in industries, such as the design of electronic cir­ cuits, computer networking, telecommunication, and perfect phylogeny. The Steiner tree problem was initiated in the Euclidean plane. Given a set of points in the Euclidean plane, the shortest network interconnect­ ing the points in the set is called the Steiner minimum tree. The Steiner minimum tree may contain some vertices which are not the given points. Those vertices are called Steiner points while the given points are called terminals. The shortest network for three terminals was first studied by Fermat (1601-1665). Fermat proposed the problem of finding a point to minimize the total distance from it to three terminals in the Euclidean plane. The direct generalization is to find a point to minimize the total distance from it to n terminals, which is still called the Fermat problem today. The Steiner minimum tree problem is an indirect generalization. Sch...

  11. Visualization of Uncertain Contour Trees

    DEFF Research Database (Denmark)

    Kraus, Martin

    2010-01-01

    Contour trees can represent the topology of large volume data sets in a relatively compact, discrete data structure. However, the resulting trees often contain many thousands of nodes; thus, many graph drawing techniques fail to produce satisfactory results. Therefore, several visualization methods...... were proposed recently for the visualization of contour trees. Unfortunately, none of these techniques is able to handle uncertain contour trees although any uncertainty of the volume data inevitably results in partially uncertain contour trees. In this work, we visualize uncertain contour trees...... by combining the contour trees of two morphologically filtered versions of a volume data set, which represent the range of uncertainty. These two contour trees are combined and visualized within a single image such that a range of potential contour trees is represented by the resulting visualization. Thus...

  12. TreeFam: 2008 Update

    DEFF Research Database (Denmark)

    Ruan, Jue; Li, Heng; Chen, Zhongzhong

    2008-01-01

    TreeFam (http://www.treefam.org) was developed to provide curated phylogenetic trees for all animal gene families, as well as orthologue and paralogue assignments. Release 4.0 of TreeFam contains curated trees for 1314 families and automatically generated trees for another 14,351 families. We have...... expanded TreeFam to include 25 fully sequenced animal genomes, as well as four genomes from plant and fungal outgroup species. We have also introduced more accurate approaches for automatically grouping genes into families, for building phylogenetic trees, and for inferring orthologues and paralogues....... The user interface for viewing phylogenetic trees and family information has been improved. Furthermore, a new perl API lets users easily extract data from the TreeFam mysql database....

  13. Generic Ising trees

    DEFF Research Database (Denmark)

    Durhuus, Bergfinnur Jøgvan; Napolitano, George Maria

    2012-01-01

    The Ising model on a class of infinite random trees is defined as a thermodynamiclimit of finite systems. A detailed description of the corresponding distribution of infinite spin configurations is given. As an application, we study the magnetization properties of such systems and prove that they......The Ising model on a class of infinite random trees is defined as a thermodynamiclimit of finite systems. A detailed description of the corresponding distribution of infinite spin configurations is given. As an application, we study the magnetization properties of such systems and prove...... that they exhibit no spontaneous magnetization. Furthermore, the values of the Hausdorff and spectral dimensions of the underlying trees are calculated and found to be, respectively,¯dh =2 and¯ds = 4/3....

  14. Explaining spatial patterns of sap flow: day-to-day shifts in relevance of site- and tree-specific controls

    Science.gov (United States)

    Hassler, Sibylle K.; Weiler, Markus; Blume, Theresa

    2015-04-01

    Transpiration is a key process in the hydrological cycle and a sound understanding and quantification of transpiration is essential for management decisions and for hydrological and climatological modelling. To assess transpiration at the tree scale sap flow velocity is commonly measured. Besides atmospheric conditions and soil moisture state, tree-specific characteristics such as species, size or social status control sap flow of individual trees. Within forest stands, properties such as species composition, basal area or stem number also affect sap flow via competition or facilitation mechanisms. Finally, sap flow patterns might also be influenced by landscape-scale characteristics such as geology, slope position or aspect because they affect water and energy availability; however, so far little is known about these larger-scale controls. We studied the relative importance of various tree- and site-specific characteristics with linear statistical models for daily sap velocity observations on 38 trees at 12 locations in mixed beech and oak forests in a catchment in Luxemburg. The temporal variation of the predictors' importance for sap velocity patterns was then related to hydro-meteorological conditions. Results indicate that a combination of tree- and site-specific controls influence sap velocity patterns, namely tree species, tree diameter, stand basal area, geology and aspect. The temporal dynamics of these controls are related to hydro-meteorological conditions, with tree-specific controls dominating when the atmospheric gradient is strong, i.e. the vapour pressure deficit is large, leading to higher sap velocities, whereas landscape-scale site characteristics are more important during weak atmospheric gradients. The importance of individual predictors also varies between spring and summer, probably due to different soil moisture and atmospheric conditions of the two periods. We conclude that both tree- and site-specific characteristics control sap velocity

  15. Forest Growth Responses to Drought at Short- and Long-Term Scales in Spain: Squeezing the Stress Memory from Tree Rings

    Directory of Open Access Journals (Sweden)

    J. Julio Camarero

    2018-02-01

    Full Text Available Drought-triggered declines in forest productivity and associated die-off events have increased considerably due to climate warming in the last decades. There is an increasing interest in quantifying the resilience capacity of forests against climate warming and drought to uncover how different stands and tree species will resist and recover after more frequent and intense droughts. Trees form annual growth rings that represent an accurate record of how forest growth responded to past droughts. Here we use dendrochronology to quantify the radial growth of different forests subjected to contrasting climatic conditions in Spain during the last half century. Particularly, we considered four climatically contrasting areas where dominant forests showed clear signs of drought-induced dieback. Studied forests included wet sites dominated by silver fir (Abies alba in the Pyrenees and beech (Fagus sylvatica stands in northern Spain, and drought-prone sites dominated by Scots pine (Pinus sylvestris in eastern Spain and black pine (Pinus nigra in the semi-arid south-eastern Spain. We quantified the growth reduction caused by different droughts and assessed the short-and long-term resilience capacity of declining vs. non-declining trees in each forest. In all cases, drought induced a marked growth reduction regardless tree vigor. However, the capacity to recover after drought (resilience at short- and long-term scales varied greatly between declining and non-declining individuals. In the case of beech and silver fir, non-declining individuals presented greater growth rates and capacity to recover after drought than declining individuals. For Scots pine, the resilience to drought was found to be lower in recent years regardless the tree vigor, but the growth reduction caused by successive droughts was more pronounced in declining than in non-declining individuals. In the black pine forest an extreme drought induced a marked growth reduction in declining

  16. Carbon and Nitrogen dynamics in deciduous and broad leaf trees under drought stress

    Science.gov (United States)

    Joseph, Jobin; Schaub, Marcus; Arend, Matthias; Saurer, Matthias; siegwolf, Rolf; Weiler, Markus; Gessler, Arthur

    2017-04-01

    Climate change is projected to lead to an increased frequency and duration of severe drought events in future. Already within the last twenty years, however, drought stress related forest mortality has been increasing across the globe. Tree and forest die off events have multiple adverse effects on ecosystem functioning and might convert previous carbon sinks to act as carbon sources instead and can thus intensify the effect of climate change and global warming. Current predictions of forest's functioning under drought and thus forest mortality under future climatic conditions are constrained by a still incomplete picture of the trees' physiological reactions that allows some trees to survive drought periods while others succumb. Concerning the effects of drought on the carbon balance and on tree hydraulics our picture is getting more complete, but still interactions between abiotic factors and pest and diseases as well as the interaction between carbon and nutrient balances as factors affecting drought induced mortality are not well understood. Reduced carbon allocation from shoots to roots might cause a lack of energy for root nutrient uptake and to a shortage of carbon skeletons for nitrogen assimilation and thus to an impaired nutrient status of trees. To tackle these points, we have performed a drought stress experiment with six different plant species, 3 broad leaf (maple, beech and oak) and 3 deciduous (pine, fir and spruce). Potted two-year-old seedlings were kept inside a greenhouse for 5 months and 3 levels of drought stress (no stress (control), intermediate and intensive drought stress) were applied by controlling water supply. Gas exchange measurements were performed periodically to monitor photosynthesis, transpiration, stomatal conductance. At the pinnacle of drought stress, we applied isotopic pulse labelling: On the one hand we exposed trees to 13CO2 to investigate on carbon dynamics and the allocation of new assimilates within the plant. Moreover

  17. Influence of windthrows and tree species on forest soil plant biomass and carbon stocks

    Science.gov (United States)

    Veselinovic, B.; Hager, H.

    2012-04-01

    The role of forests has generally been recognized in climate change mitigation and adaptation strategies and policies (e.g. Kyoto Protocol within articles 3.3 and 3.4, RES-E Directive of EU, Country Biomass Action Plans etc.). Application of mitigation actions, to decrease of CO2-emissions and, as the increase of carbon(C)-stocks and appropriate GHG-accounting has been hampered due to a lack of reliable data and good statistical models for the factors influencing C-sequestration in and its release from these systems (e.g. natural and human induced disturbances). Highest uncertainties are still present for estimation of soil C-stocks, which is at the same time the second biggest C-reservoir on earth. Spruce monocultures have been a widely used management practice in central Europe during the past century. Such stands are in lower altitudes (e.g. submontane to lower montane elevation zone) and on heavy soils unstable and prone to disturbances, especially on blowdown. As the windthrow-areas act as CO2-source, we hypothesize that conversion to natural beech and oak forests will provide sustainable wood supply and higher stability of stands against blowdown, which simultaneously provides the long-term belowground C-sequestration. This work focuses on influence of Norway spruce, Common beech and Oak stands on belowground C-dynamics (mineral soil, humus and belowground biomass) taking into consideration the increased impact of windthrows on spruce monocultures as a result of climate change. For this purpose the 300-700m altitude and pseudogley (planosols/temporally logged) soils were chosen in order to evaluate long-term impacts of the observed tree species on belowground C-dynamics and human induced disturbances on secondary spruce stands. Using the false chronosequence approach, the C-pools have been estimated for different compartments and age classes. The sampling of forest floor and surface vegetation was done using 30x30 (homogenous plots) and 50x50cm (inhomogeneous

  18. Microscopic identification of changes in beech (Fagus sylvatica L. and pine (Pinus sylvestris L. cell structure after drying using high-frequency energy of the microwave band

    Directory of Open Access Journals (Sweden)

    Andrea Nasswettrová

    2011-01-01

    Full Text Available High-frequency energy transfer represents a progressive technology with an increasing range of industrial application. One of the main advantages of microwave technology is the volumetric principle of energy transfer. Based on this fact, the gradients of moisture content and temperature are identical and when the wood is dried it helps transport moisture from porous material and it also helps and transport free water whit lumen of cells. From a practical viewpoint, microwave heating increases the quality of the dried material and reduces the necessary processing. The quality of a dry material is an essential input parameter for other technological procedures and it depends on the deformations created in its cell structure. Therefore, the monitoring of changes brought about during the drying process is necessary. The aim of this study was to identify the changes in the microscopic structure of the wood of beech (Fagus Sylvatica L. and pine (Pinus Sylvestris L. dried using the high-frequency energy of the microwave band. The microscopic structure of a material modified by microwaves was photographed by means of a low-vacuum microscope and then visually compared with the native structure. The results show that the structure of beech and pine wood during the time of the proposed drying regime does not differ considerably from the native structure. This outcome is documented in a digital form and it confirms the harmless character of microwave heating towards wood structure in the conditions of optimum drying parameters.

  19. Changes in forms of available nitrogen and respiration in soil of beech forest as a reaction to a deforestation resulting from wind storm

    Directory of Open Access Journals (Sweden)

    Aleš Kučera

    2013-01-01

    Full Text Available The article deals with the reaction of soil environment to a violent deforestation resulting from a wind storm. As a material, permanent inventory plot located in Training Forest Enterprise Masaryk Forest Křtiny was selected. The plot represents beech high forest, where soil was sampled from four types of sample plots: (1 maternal forest representing situation before the storm; (2 zone of transition from the maternal forest to the open area; (3 reafforested clearing; (4 natural evolution. From each sample plot type, 6 mixed samples of Ah horizon were analysed to assess N-ammonium (N-NH4+ and N-nitrates (NO3− content and respiration activity. The results show a significant difference between the respiration activities of the particular sample plots, as well as a significant difference in the content of N-ammonium and N-nitrate forms, the maternal forest representing a site of the lowest biological (and respiration activity on the one hand, and, on the other hand, site of high N-ammonium and low N-nitrate content, respectively. From the results, intensive nitrification caused by the deforestation is evident. The results are to be used as a starting level for a long-term observation of reaction of the forest beech ecosystem to deforestation and selected types of forest management.

  20. Portraits of Tree Families

    NARCIS (Netherlands)

    Balgooy, van M.M.J.

    1998-01-01

    With the publication of the second volume of the series ‘Malesian Seed Plants’, entitled ‘Portraits of Tree Families’, I would like to refer to the Introduction of the first volume, ‘Spot-characters’ for a historical background and an explanation of the aims of this series. The present book treats

  1. Oak Tree Planting Project

    Science.gov (United States)

    Sherryl L. Nives; William D. Tietje; William H. Weitkamp

    1991-01-01

    An Oak Tree Planting Project was conducted during 1989/90 in San Luis Obispo County by the Integrated Hardwood Range Management Program (IHRMP)/Central Coast. The local media and an IHRMP workshop were used to publicize the Planting Project and give information on the status of oaks (Quercus spp.) in California and oak planting techniques. Outreach...

  2. P{owering 'Trees

    Indian Academy of Sciences (India)

    Melia dubia Cav. of Meliaceae is a large deciduous tree. Leaves are compound with toothed leaflets. Flowers are small, greenish-yellow in much-branched inflorescences. Fruits are green, ellipsoidal with a single seed covered by hard portion ( as in a mango fruit) and surrounded by fleshy pulp outside. The bark is bitter ...

  3. Base tree property

    Czech Academy of Sciences Publication Activity Database

    Balcar, B.; Doucha, Michal; Hrušák, M.

    2015-01-01

    Roč. 32, č. 1 (2015), s. 69-81 ISSN 0167-8094 R&D Projects: GA AV ČR IAA100190902 Institutional support: RVO:67985840 Keywords : forcing * Boolean algebras * base tree Subject RIV: BA - General Mathematics Impact factor: 0.614, year: 2015 http://link.springer.com/article/10.1007/s11083-013-9316-2

  4. How to Prune Trees

    Science.gov (United States)

    Peter Bedker; Joseph O' Brien; Manfred Mielke

    2012-01-01

    The objective of pruning is to produce strong, healthy, attractive plants. By understanding how, when and why to prune, and by following a few simple principles, this objective can be achievedHow to Prune Trees (Revised 2012) Agency Publisher: Agriculture Dept., Forest Service, Northeastern Area State and Price forestry USA List Price:$4.00 Sale...

  5. Multiquarks and Steiner trees

    International Nuclear Information System (INIS)

    Richard, Jean-Marc

    2010-01-01

    A brief review review is presented of models tentatively leading to stable multiquarks. A new attempt is presented, based on a Steiner-tree model of confinement, which is inspired by by QCD. It leads to more attraction than the empirical colour-additive model used in earlier multiquark calculations, and predict several multiquark states in configurations with different flavours.

  6. Christmas Tree Category Manual.

    Science.gov (United States)

    Bowman, James S.; Turmel, Jon P.

    This manual provides information needed to meet the standards for pesticide applicator certification. Pests and diseases of christmas tree plantations are identified and discussed. Section one deals with weeds and woody plants and the application, formulation and effects of herbicides in controlling them. Section two discusses specific diseases…

  7. Chapter 5 - Tree Mortality

    Science.gov (United States)

    Mark J. Ambrose

    2014-01-01

    Tree mortality is a natural process in all forest ecosystems. Extremely high mortality, however, can also be an indicator of forest health issues. On a regional scale, high mortality levels may indicate widespread insect or disease problems. High mortality may also occur if a large proportion of the forest in a particular region is made up of older, senescent stands....

  8. The TS-Tree

    DEFF Research Database (Denmark)

    Assent, Ira; Krieger, Ralph; Afschari, Farzad

    2008-01-01

    Continuous growth in sensor data and other temporal data increases the importance of retrieval and similarity search in time series data. Efficient time series query processing is crucial for interactive applications. Existing multidimensional indexes like the R-tree provide efficient querying fo...

  9. Tree Size Comparison of Some Important Street Trees Growing at ...

    African Journals Online (AJOL)

    PROF HORSFALL

    ABSTRACT: The importance of trees in urban environment is now widely recognized as they cleanse the ... urban environment prevent solar radiation from ..... In urban areas, tree height is an important consideration in deciding what species to plant and/or where to plant them. Considering that many urban tree. Fig. 7.

  10. Solution trees as a basis for game tree search

    NARCIS (Netherlands)

    A. de Bruin (Arie); W.H.L.M. Pijls (Wim); A. Plaat (Aske)

    1994-01-01

    textabstractA game tree algorithm is an algorithm computing the minimax value of the root of a game tree. Many algorithms use the notion of establishing proofs that this value lies above or below some boundary value. We show that this amounts to the construction of a solution tree. We discuss the

  11. A suffix tree or not a suffix tree?

    DEFF Research Database (Denmark)

    Starikovskaya, Tatiana; Vildhøj, Hjalte Wedel

    2015-01-01

    , in particular we do not require that S ends with a unique symbol. This corresponds to considering the more general definition of implicit or extended suffix trees. Such general suffix trees have many applications and are for example needed to allow efficient updates when suffix trees are built online. Deciding...

  12. Tree Transduction Tools for Cdec

    Directory of Open Access Journals (Sweden)

    Austin Matthews

    2014-09-01

    Full Text Available We describe a collection of open source tools for learning tree-to-string and tree-to-tree transducers and the extensions to the cdec decoder that enable translation with these. Our modular, easy-to-extend tools extract rules from trees or forests aligned to strings and trees subject to different structural constraints. A fast, multithreaded implementation of the Cohn and Blunsom (2009 model for extracting compact tree-to-string rules is also included. The implementation of the tree composition algorithm used by cdec is described, and translation quality and decoding time results are presented. Our experimental results add to the body of evidence suggesting that tree transducers are a compelling option for translation, particularly when decoding speed and translation model size are important.

  13. Selecting Landscape Plants: Shade Trees

    OpenAIRE

    Relf, Diane; Appleton, Bonnie Lee, 1948-2012; Close, David

    2015-01-01

    Because of the permanency of trees and their importance in the landscape, care must be taken to select the best species for each situation. This publication goes over how to choose landscape trees that are shade tolerant.

  14. Mineralisation, leaching and stabilisation of 13C-labelled leaf and twig litter in a beech forest soil

    Directory of Open Access Journals (Sweden)

    F. Hagedorn

    2011-08-01

    Full Text Available Very few field studies have quantified the different pathways of C loss from decomposing litter even though the partitioning of C fluxes is essential to understand soil C dynamics. Using 0.75 kg m−2 of 13C-depleted leaf (δ13C = −40.8 ‰ and 2 kg m−2 of twig litter (δ13C = −38.4 ‰, we tracked the litter-derived C in soil CO2 effluxes, dissolved organic C (DOC, and soil organic matter of a beech forest in the Swiss Jura. Autotrophic respiration was reduced by trenching. Our results show that mineralisation was the main pathway of C loss from decomposing litter over 1 yr, amounting to 24 and 31 % of the added twig and leaf litter. Contrary to our expectations, the leaf litter C was mineralised only slightly (1.2 times more rapidly than the twig litter C. The leaching of DOC from twigs amounted to half of that from leaves throughout the experiment (2 vs. 4 % of added litter C. Tracing the litter-derived DOC in the soil showed that DOC from both litter types was mostly removed (88–96 % with passage through the top centimetres of the mineral soil (0–5 cm where it might have been stabilised. In the soil organic C at 0–2 cm depth, we indeed recovered 4 % of the initial twig C and 8 % of the leaf C after 1 yr. Much of the 13C-depleted litter remained on the soil surface throughout the experiment: 60 % of the twig litter C and 25 % of the leaf litter C. From the gap in the 13C-mass balance based on C mineralisation, DOC leaching, C input into top soils, and remaining litter, we inferred that another 30 % of the leaf C but only 10 % of twig C could have been transported via soil fauna to soil depths below 2 cm. In summary, over 1 yr, twig litter was mineralised more rapidly relative to leaf litter than expected, and much less of the twig-derived C was transported to the mineral soil than of the leaf-derived C. Both findings provide some evidence that twig litter could contribute less to the C storage in these base-rich forest soils than

  15. Selecting Landscape Plants: Flowering Trees

    OpenAIRE

    Relf, Diane; Appleton, Bonnie Lee, 1948-2012

    2009-01-01

    This publication helps the reader to select wisely among the many species and varieties of flowering trees available. The following are considerations that should be taken into account when choosing flowering trees for the home landscape: selections factors, environmental responses, availability and adaptability, and flowering tree descriptions.

  16. Inferences from growing trees backwards

    Science.gov (United States)

    David W. Green; Kent A. McDonald

    1997-01-01

    The objective of this paper is to illustrate how longitudinal stress wave techniques can be useful in tracking the future quality of a growing tree. Monitoring the quality of selected trees in a plantation forest could provide early input to decisions on the effectiveness of management practices, or future utilization options, for trees in a plantation. There will...

  17. Generalising tree traversals to DAGs

    DEFF Research Database (Denmark)

    Bahr, Patrick; Axelsson, Emil

    2015-01-01

    We present a recursion scheme based on attribute grammars that can be transparently applied to trees and acyclic graphs. Our recursion scheme allows the programmer to implement a tree traversal and then apply it to compact graph representations of trees instead. The resulting graph traversals avoid...

  18. Our Air: Unfit for Trees.

    Science.gov (United States)

    Dochinger, Leon S.

    To help urban, suburban, and rural tree owners know about air pollution's effects on trees and their tolerance and intolerance to pollutants, the USDA Forest Service has prepared this booklet. It answers the following questions about atmospheric pollution: Where does it come from? What can it do to trees? and What can we do about it? In addition,…

  19. The Hopi Fruit Tree Book.

    Science.gov (United States)

    Nyhuis, Jane

    Referring as often as possible to traditional Hopi practices and to materials readily available on the reservation, the illustrated booklet provides information on the care and maintenance of young fruit trees. An introduction to fruit trees explains the special characteristics of new trees, e.g., grafting, planting pits, and watering. The…

  20. Rectilinear Full Steiner Tree Generation

    DEFF Research Database (Denmark)

    Zachariasen, Martin

    1999-01-01

    The fastest exact algorithm (in practice) for the rectilinear Steiner tree problem in the plane uses a two-phase scheme: First, a small but sufficient set of full Steiner trees (FSTs) is generated and then a Steiner minimum tree is constructed from this set by using simple backtrack search, dynamic...

  1. DensiTree: making sense of sets of phylogenetic trees.

    Science.gov (United States)

    Bouckaert, Remco R

    2010-05-15

    Bayesian analysis through programs like BEAST (Drummond and Rumbaut, 2007) and MrBayes (Huelsenbeck et al., 2001) provides a powerful method for reconstruction of evolutionary relationships. One of the benefits of Bayesian methods is that well-founded estimates of uncertainty in models can be made available. So, for example, not only the mean time of a most recent common ancestor (tMRCA) is estimated, but also the spread. This distribution over model space is represented by a set of trees, which can be rather large and difficult to interpret. DensiTree is a tool that helps navigating these sets of trees. The main idea behind DensiTree is to draw all trees in the set transparently. As a result, areas where a lot of the trees agree in topology and branch lengths show up as highly colored areas, while areas with little agreement show up as webs. This makes it possible to quickly get an impression of properties of the tree set such as well-supported clades, distribution of tMRCA and areas of topological uncertainty. Thus, DensiTree provides a quick method for qualitative analysis of tree sets. DensiTree is freely available from http://compevol.auckland.ac.nz/software/DensiTree/. The program is licensed under GPL and source code is available. remco@cs.auckland.ac.nz

  2. Tree Colors: Color Schemes for Tree-Structured Data.

    Science.gov (United States)

    Tennekes, Martijn; de Jonge, Edwin

    2014-12-01

    We present a method to map tree structures to colors from the Hue-Chroma-Luminance color model, which is known for its well balanced perceptual properties. The Tree Colors method can be tuned with several parameters, whose effect on the resulting color schemes is discussed in detail. We provide a free and open source implementation with sensible parameter defaults. Categorical data are very common in statistical graphics, and often these categories form a classification tree. We evaluate applying Tree Colors to tree structured data with a survey on a large group of users from a national statistical institute. Our user study suggests that Tree Colors are useful, not only for improving node-link diagrams, but also for unveiling tree structure in non-hierarchical visualizations.

  3. 75 FR 25103 - Tree Assistance Program

    Science.gov (United States)

    2010-05-07

    ... produced for commercial purposes, such as a maple tree for syrup, papaya tree, or orchard tree. Trees used... tomato plants, biennials such as the plants that produce strawberries, and annuals such as pumpkins...

  4. The Response of Basal Area Increment in Old Sprout-origin Sessile Oak (Quercus petraea (Matt. Liebl. Trees During Their Conversion to a Coppice-with-standards

    Directory of Open Access Journals (Sweden)

    Zdeněk Adamec

    2014-01-01

    Full Text Available This paper addresses the response of adult sprout-origin sessile oaks (Quercus petraea (Matt. Liebl. to a strong release. Our research plot was established at the Training Forest Enterprise of Mendel University in Brno (Czech Republic at the turn of 2008/2009. The plot is situated on a plateau with mesotrofic soil in a beech-oak forest vegetation zone at an altitude of 410 m above sea level. Tree responses were monitored using precise girth measurements. During the first year after the release, the basal area increment showed a positive correlation with only the tree diameter. During the second and third year, the basal area increment was also correlated with the release intensity. During the third year, the basal area increment was explained by the tree diameter, the crown shape, and the release intensity as well as individual types of epicormic shoot occurrence. The occurrence of epicormic shoots in the lower part of the trunks and umbel-shaped crowns increased the basal area increment. In the first, second and third year after thinning, the model explained 11.79%, 11.25% and 28.99%, respectively, of the basal area increment variability. Adult trees of sprout origin responded to a strong release very early (within two years after felling.

  5. Fault-Tree Compiler Program

    Science.gov (United States)

    Butler, Ricky W.; Martensen, Anna L.

    1992-01-01

    FTC, Fault-Tree Compiler program, is reliability-analysis software tool used to calculate probability of top event of fault tree. Five different types of gates allowed in fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N. High-level input language of FTC easy to understand and use. Program supports hierarchical fault-tree-definition feature simplifying process of description of tree and reduces execution time. Solution technique implemented in FORTRAN, and user interface in Pascal. Written to run on DEC VAX computer operating under VMS operating system.

  6. Making CSB + -Trees Processor Conscious

    DEFF Research Database (Denmark)

    Samuel, Michael; Pedersen, Anders Uhl; Bonnet, Philippe

    2005-01-01

    Cache-conscious indexes, such as CSB+-tree, are sensitive to the underlying processor architecture. In this paper, we focus on how to adapt the CSB+-tree so that it performs well on a range of different processor architectures. Previous work has focused on the impact of node size on the performance...... of the CSB+-tree. We argue that it is necessary to consider a larger group of parameters in order to adapt CSB+-tree to processor architectures as different as Pentium and Itanium. We identify this group of parameters and study how it impacts the performance of CSB+-tree on Itanium 2. Finally, we propose...

  7. Trees for future forests

    DEFF Research Database (Denmark)

    Lobo, Albin

    Climate change creates new challenges in forest management. The increase in temperature may in the long run be beneficial for the forests in the northern latitudes, but the high rate at which climate change is predicted to proceed will make adaptation difficult because trees are long living sessile...... of precipitation. Adaptive traits such as phenology which is sensitive to changes in temperature and drought resistance as a response to water scarcity are studied. Quantitative genetics is extensively used in field phenotyping to identify the availability of sufficient genetic variation within species. Other...... as a faster mechanism in aiding climate change adaptation in trees. Drought resistance varied among the different species belonging to a single genus showing the inherent capacity of native species to overcome water scarcity in severely drought prone regions of the world. More research into the important...

  8. Wood for the trees

    Directory of Open Access Journals (Sweden)

    Rob Garbutt

    2013-10-01

    Full Text Available Our paper focuses on the materiality, cultural history and cultural relations of selected artworks in the exhibition Wood for the trees (Lismore Regional Gallery, New South Wales, Australia, 10 June – 17 July 2011. The title of the exhibition, intentionally misreading the aphorism “Can’t see the wood for the trees”, by reading the wood for the resource rather than the collective wood[s], implies conservation, preservation, and the need for sustaining the originating resource. These ideas have particular resonance on the NSW far north coast, a region once rich in rainforest. While the Indigenous population had sustainable practices of forest and land management, the colonists deployed felling and harvesting in order to convert the value of the local, abundant rainforest trees into high-value timber. By the late twentieth century, however, a new wave of settlers launched a protest movements against the proposed logging of remnant rainforest at Terania Creek and elsewhere in the region. Wood for the trees, curated by Gallery Director Brett Adlington, plays on this dynamic relationship between wood, trees and people. We discuss the way selected artworks give expression to the themes or concepts of productive labour, nature and culture, conservation and sustainability, and memory. The artworks include Watjinbuy Marrawilil’s (1980 Carved ancestral figure ceremonial pole, Elizabeth Stops’ (2009/10 Explorations into colonisation, Hossein Valamanesh’s (2008 Memory stick, and AñA Wojak’s (2008 Unread book (in a forgotten language. Our art writing on the works, a practice informed by Bal (2002, Muecke (2008 and Papastergiadis (2004, becomes a conversation between the works and the themes or concepts. As a form of material excess of the most productive kind (Grosz, 2008, p. 7, art seeds a response to that which is in the air waiting to be said of the past, present and future.

  9. Pushdown machines for the macro tree transducer

    NARCIS (Netherlands)

    Engelfriet, Joost; Vogler, Heiko

    1986-01-01

    The macro tree transducer can be considered as a system of recursive function procedures with parameters, where the recursion is on a tree (e.g., the syntax tree of a program). We investigate characterizations of the class of tree (tree-to-string) translations which is induced by macro tree

  10. Recursive Trees for Practical ORAM

    Directory of Open Access Journals (Sweden)

    Moataz Tarik

    2015-06-01

    Full Text Available We present a new, general data structure that reduces the communication cost of recent tree-based ORAMs. Contrary to ORAM trees with constant height and path lengths, our new construction r-ORAM allows for trees with varying shorter path length. Accessing an element in the ORAM tree results in different communication costs depending on the location of the element. The main idea behind r-ORAM is a recursive ORAM tree structure, where nodes in the tree are roots of other trees. While this approach results in a worst-case access cost (tree height at most as any recent tree-based ORAM, we show that the average cost saving is around 35% for recent binary tree ORAMs. Besides reducing communication cost, r-ORAM also reduces storage overhead on the server by 4% to 20% depending on the ORAM’s client memory type. To prove r-ORAM’s soundness, we conduct a detailed overflow analysis. r-ORAM’s recursive approach is general in that it can be applied to all recent tree ORAMs, both constant and poly-log client memory ORAMs. Finally, we implement and benchmark r-ORAM in a practical setting to back up our theoretical claims.

  11. Mathematical foundations of event trees

    International Nuclear Information System (INIS)

    Papazoglou, Ioannis A.

    1998-01-01

    A mathematical foundation from first principles of event trees is presented. The main objective of this formulation is to offer a formal basis for developing automated computer assisted construction techniques for event trees. The mathematical theory of event trees is based on the correspondence between the paths of the tree and the elements of the outcome space of a joint event. The concept of a basic cylinder set is introduced to describe joint event outcomes conditional on specific outcomes of basic events or unconditional on the outcome of basic events. The concept of outcome space partition is used to describe the minimum amount of information intended to be preserved by the event tree representation. These concepts form the basis for an algorithm for systematic search for and generation of the most compact (reduced) form of an event tree consistent with the minimum amount of information the tree should preserve. This mathematical foundation allows for the development of techniques for automated generation of event trees corresponding to joint events which are formally described through other types of graphical models. Such a technique has been developed for complex systems described by functional blocks and it is reported elsewhere. On the quantification issue of event trees, a formal definition of a probability space corresponding to the event tree outcomes is provided. Finally, a short discussion is offered on the relationship of the presented mathematical theory with the more general use of event trees in reliability analysis of dynamic systems

  12. (Almost) practical tree codes

    KAUST Repository

    Khina, Anatoly

    2016-08-15

    We consider the problem of stabilizing an unstable plant driven by bounded noise over a digital noisy communication link, a scenario at the heart of networked control. To stabilize such a plant, one needs real-time encoding and decoding with an error probability profile that decays exponentially with the decoding delay. The works of Schulman and Sahai over the past two decades have developed the notions of tree codes and anytime capacity, and provided the theoretical framework for studying such problems. Nonetheless, there has been little practical progress in this area due to the absence of explicit constructions of tree codes with efficient encoding and decoding algorithms. Recently, linear time-invariant tree codes were proposed to achieve the desired result under maximum-likelihood decoding. In this work, we take one more step towards practicality, by showing that these codes can be efficiently decoded using sequential decoding algorithms, up to some loss in performance (and with some practical complexity caveats). We supplement our theoretical results with numerical simulations that demonstrate the effectiveness of the decoder in a control system setting.

  13. Submodular unsplittable flow on trees

    DEFF Research Database (Denmark)

    Adamaszek, Anna Maria; Chalermsook, Parinya; Ene, Alina

    2016-01-01

    We study the Unsplittable Flow problem (UFP) on trees with a submodular objective function. The input to this problem is a tree with edge capacities and a collection of tasks, each characterized by a source node, a sink node, and a demand. A subset of the tasks is feasible if the tasks can...... simultaneously send their demands from the source to the sink without violating the edge capacities. The goal is to select a feasible subset of the tasks that maximizes a submodular objective function. Our main result is an O(k log n)-approximation algorithm for Submodular UFP on trees where k denotes...... the pathwidth of the given tree. Since every tree has pathwidth O(log n), we obtain an O(log2 n) approximation for arbitrary trees. This is the first non-trivial approximation guarantee for the problem and it matches the best approximation known for UFP on trees with a linear objective function. Our main...

  14. Rate of tree carbon accumulation increases continuously with tree size

    Science.gov (United States)

    Stephenson, N.L.; Das, A.J.; Condit, R.; Russo, S.E.; Baker, P.J.; Beckman, N.G.; Coomes, D.A.; Lines, E.R.; Morris, W.K.; Rüger, N.; Álvarez, E.; Blundo, C.; Bunyavejchewin, S.; Chuyong, G.; Davies, S.J.; Duque, Á.; Ewango, C.N.; Flores, O.; Franklin, J.F.; Grau, H.R.; Hao, Z.; Harmon, M.E.; Hubbell, S.P.; Kenfack, D.; Lin, Y.; Makana, J.-R.; Malizia, A.; Malizia, L.R.; Pabst, R.J.; Pongpattananurak, N.; Su, S.-H.; Sun, I-F.; Tan, S.; Thomas, D.; van Mantgem, P.J.; Wang, X.; Wiser, S.K.; Zavala, M.A.

    2014-01-01

    Forests are major components of the global carbon cycle, providing substantial feedback to atmospheric greenhouse gas concentrations. Our ability to understand and predict changes in the forest carbon cycle—particularly net primary productivity and carbon storage - increasingly relies on models that represent biological processes across several scales of biological organization, from tree leaves to forest stands. Yet, despite advances in our understanding of productivity at the scales of leaves and stands, no consensus exists about the nature of productivity at the scale of the individual tree, in part because we lack a broad empirical assessment of whether rates of absolute tree mass growth (and thus carbon accumulation) decrease, remain constant, or increase as trees increase in size and age. Here we present a global analysis of 403 tropical and temperate tree species, showing that for most species mass growth rate increases continuously with tree size. Thus, large, old trees do not act simply as senescent carbon reservoirs but actively fix large amounts of carbon compared to smaller trees; at the extreme, a single big tree can add the same amount of carbon to the forest within a year as is contained in an entire mid-sized tree. The apparent paradoxes of individual tree growth increasing with tree size despite declining leaf-level and stand-level productivity can be explained, respectively, by increases in a tree’s total leaf area that outpace declines in productivity per unit of leaf area and, among other factors, age-related reductions in population density. Our results resolve conflicting assumptions about the nature of tree growth, inform efforts to understand and model forest carbon dynamics, and have additional implications for theories of resource allocation and plant senescence.

  15. Effect of water stage and tree stand composition on spatiotemporal differentiation of spring water chemistry draining Carpathian flysch slopes (Gorce Mts).

    Science.gov (United States)

    Jasik, Michał; Małek, Stanisław; Żelazny, Mirosław

    2017-12-01

    The purpose of this study was to identify the factors affecting spring water chemistry in different tree stands and to measure the influence of water stage on the physicochemical parameters of spring waters in a small Carpathian catchment. Water samples were collected three times per year at various stages of the water: after the spring thaw, after a period of heavy rain and after a dry period in 2011 and 2012. Water samples were left in the laboratory to reach room temperature (19-20°C) and analyzed for EC (reference T=25°C) and pH. After filtration through 0.45μm PTFE syringe filters, the water samples were analyzed by means of ion chromatography using a DIONEX ICS 5000 unit. The following ions were analyzed: Ca 2+ , Mg 2+ , Na + , K + , HCO 3 - , SO 4 2- , Cl - , and NO 3 - . Multivariate analysis (PCA) allowed the identification of two factors of spring water chemistry: factor 1, water stage and factor 2 tree stand composition. Seasonal variation of spring water chemistry showed that, higher pH values and mineralization as well as higher concentrations of Ca 2+ and Mg 2+ were measured during low water stage periods while lower EC and pH values were noted after spring snowmelt and rainfall, when higher concentrations of NO 3 - and SO 4 2- were also found. Higher concentrations of Ca 2+ and Mg 2+ and higher pH of spring waters located in beech-fir stands and in those mixed with a large proportion of beech as well as a lower concentration of Ca 2+ , Mg 2+ and HCO 3 - , pH, conductivity and mineralization of these spring waters, in which the alimentation areas were covered by upper subalpine spruce stands were noted. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Carbon and Nitrogen dynamics in forest soils depending on light conditions and tree species

    Science.gov (United States)

    Veselinovic, Bojana; Hager, Herbert

    2013-04-01

    Climate change mitigation actions under the Kyoto Protocol apply among other decreases of CO2-emissions and/or increases of carbon (C) stocks. As soils represent the second biggest C-reservoir on Earth, an exact estimation of the stocks and reliable knowledge on C-dynamics in forest soils is of high importance. Anyhow, here, the accurate GHG-accounting, emission reductions and increase in C stocks is hampered due to lack of reliable data and solid statistical methods for the factors which influence C-sequestration in and its release from these systems. In spite of good progress in the scientific research, these factors are numerous and diverse in their interactions. This work focuses on influence of the economically relevant tree species - Picea abies, Fagus sylvatica and Quercus spp. - and light conditions on forest floor and mineral soil C and N dynamics in forest soils. Spruce monocultures have been widely used management practices in central European forests during the past century. Such stands are in lower altitudes and on heavy and water logged soils unstable and prone to disturbances, especially to windthrows. We hypothesize that windthrow areas loose C & N and that the establishment of the previous nutrient stocks is, if at all, only possible to be reached over the longer periods of time. We research also how the increased OM depletion affects the change of C & N stocks in forest floor vs. mineral soil. Conversion of such secondary spruce monocultures to site adequate beech and oak forests may enable higher stocks allocated predominantly as stable organic carbon and as plant available nitrogen. For this purpose sites at 300-700 m altitude with planosols were chosen in the region of the Northern Alpine Foothills. A false chronosequence approach was used in order to evaluate the impacts of the tree species and change in light conditions on dynamic of C & N in the forest floor and mineral soil, over the period 0-100 (for oak 120 y.) years. The C- and N

  17. Tree species influence soil-atmosphere fluxes of the greenhouse gases CO2, CH4 and N2O

    Science.gov (United States)

    Steffens, Christina; Vesterdal, Lars; Pfeiffer, Eva-Maria

    2016-04-01

    In the temperate zone, forests are the greatest terrestrial sink for atmospheric CO2, and tree species affect soil C stocks and soil CO2 emissions. When considering the total greenhouse gas (GHG) balance of the forest soil, the relevant GHGs CH4 and N2O should also be considered as they have a higher global warming potential than CO2. The presented data are first results from a field study in a common garden site in Denmark where tree species with ectomycorrhizal colonization (beech - Fagus sylvatica, oak - Quercus robur) and with arbuscular mycorrhizal colonization (maple - Acer pseudoplatanus, ash - Fraxinus excelsior) have been planted in monocultures in adjacent blocks of about 0.25 ha in the year 1973 on former arable land. The soil-atmosphere fluxes of all three gases were measured every second week since August 2015. The hypothesis is that the total GHG efflux from forest soil would differ between species, and that these differences could be related to the type of mycorrhizal association and leaf litter quality. Preliminary results (August to December 2015) indicate that tree species influence the fluxes (converted to CO2-eq) of the three GHGs. Total soil CO2 efflux was in the low end of the range reported for temperate broadleaved forests but similar to the measurements at the same site approximately ten years ago. It was highest under oak (9.6±2.4 g CO2 m-2 d-1) and lowest under maple (5.2±1.6 g CO2 m-2 d-1). In contrast, soil under oak was a small but significant sink for CH4(-0.005±0.003 g CO2-eq m-2 d-1), while there were almost no detectable CH4 fluxes in maple. Emissions of N2O were highest under beech (0.6±0.6 g CO2-eq m-2 d-1) and oak (0.2±0.09 g CO2-eq m-2 d-1) and lowest under ash (0.03±0.04 g CO2-eq m-2 d-1). In the total GHG balance, soil CH4 uptake was negligible (≤0.1% of total emissions). Emissions of N2O (converted to CO2-eq) contributed mycorrhiza and produce leaf litter with a lower lignin:N ratio.

  18. Investigation on the Scratch Strength of Clear Paints Used in Furniture Industries on the Wood Species Beech, Elm, Alder and Spruce

    Directory of Open Access Journals (Sweden)

    Mohammad Ghofrani

    2014-05-01

    Full Text Available In This research, the scratch strength (Cross-Cut Test of clear paints (nitrocellulose lacquers and acid catalyst lacquers of wood species Beech, Elm, Alder and spruce were studied as a function of moisture content (MC of the samples. For this purpose, lumbers (550×110×12 mm were cut from sapwood in tangential surfaces and were air dried for one month according to wood drying procedures. Then, for pre-conditioning of moisture content, at the levels of 8%, 12% and 15%, the samples were placed in three clima rooms. Then, finish applied and strength tests were performed. The results revealed that for acid catalyst lacquers the highest scratch strength (10.4% belongs to Elm wood with 8% moisture content, and the lowest scratch strength (53.6% belongs to Spruce wood with nitrocellulose lacquers having 15% moisture content.

  19. Native lignin for bonding fiber boards - evaluation of bonding mechanisms in boards made from laccase-treated fibers of beech (Fagus sylvatica)

    DEFF Research Database (Denmark)

    Felby, Claus; Thygesen, Lisbeth Garbrecht; Sanadi, Anand

    2004-01-01

    The auto-adhesion of beech wood (Fagus sylvatica) fibers can be enhanced by a pretreatment of the fibers with a phenol oxidase enzyme. The mechanism of enzymatic catalyzed bonding is linked to the generation of stable radicals in lignin by oxidation. Fiberboards made from laccase-treated fibers...... have a high wet strength compared to boards made from untreated fibers. This indicates better fiber-fiber interactions and improved fiber-fiber stress transfer. The surface of laccase-treated fibers shows a markedly increased hydrophobicity as well as a change in the chemical composition, which...... indicate that lignin extractives are precipitated on the fiber surfaces. The improved bonding may be related to several factors, linked to a more lignin rich fiber surface, such as surface molecular entanglements and covalent bonding between fibers through cross-linking of radicals. (C) 2004 Published...

  20. TREE SYMBOLISM IN SLAVIC FOLK CULTURE: APPLE TREE

    Directory of Open Access Journals (Sweden)

    Tatyana A. Agapkina

    2017-03-01

    Full Text Available The essay focuses on the mythopoetic image of the apple tree and its ritual use in traditional culture and folklore of the Slavic nations. The work employs folklore material alongside ethnographic and linguistic data that accentuates and develops the folklore symbolism of the apple tree. I argue that this image is comprised of a number of relatively autonomous fragments. The apple tree and its apples are a family metaphor of a kind symbolizing a mother and a child. In wedding folklore, the apple tree stands for a bride as the wedding ritual testifies; apple tree branches are widely used in the ritual itself (as a ritual tree or as material used in the making of a wedding banner, wedding wreaths, decorations for a wedding loaf [karavai], etc.. Another manifestation of the apple tree in folklore is the tree of knowledge; it relates the image to a large number of legendary etiological plots such as: Eve’s temptation by the Serpent, fall of Eve and Adam, the origin of Adam’s Apple (adam, prohibition to eat apples before the church holiday of Transfiguration and some others. At the same time, their autonomy regardless, the fragments of the mythopoetic image of the apple tree form part of the solid folklore universe and counteract with each other within this framework.

  1. Decomposition performance of animals as an indicator of stress acting on beech-forest ecosystems - microcosmos experiments with carbon-14-labelled litter components

    International Nuclear Information System (INIS)

    Schaefer, M.; Wolters, V.

    1988-01-01

    The effect of acid rain and heavy metals on the biotic interactions in the soil of beech forest with mull, must, and limed must was investigated with the aid of close-to-nature microcosmos systems. Parameters made use of were the decomposition of carbon-14-labelled litter components and the turnover of the microflora in C, N, and P. As the results show, increased proton uptake will bear on rearly every stage of the decomposition process in mull soils. As a result, there may be litter accumulation on the ground and first signs of humus disintegration in the mineral soil of mull soils. A direct relation between the acidity of the environment and the extent of decomposition inhibition does not exist. Despite wide-ranging impairment of edaphic animals, the activity of the ground fauna still is to be considered as the most important buffer system of soils rich in bases. Acidic condition of the beech forest soils with the humus form 'must' led to drastic inhibition of litter decomposition, to a change of the effect of edaphic animals, and to an increase in N mineralization. The grazing animals frequently aggravate the decomposition inhibition resulting from acid precipitation. The comparision of the decomposition process in a soil containing must as compared to one containing mull showed acidic soils to be on a lower biological buffer level than soils rich in bases. The main buffer capacity of acidic soils lies in the microflora, which is adapted to sudden increases in acidity and which recovers quickly. In the opinion of the authors, simple liming is not enough to increase the long-term biogenic stability of a forest ecosystem. A stabilizing effect of the fauna, for instance on nitrogen storage, is possible only if forest care measuries are carried out, for instance careful loosening of the mineral soil, which will attract earthworm species penetrating deeply into the soil. (orig./MG) With 12 refs., 6 figs [de

  2. Overexpression of a Protein Phosphatase 2C from Beech Seeds in Arabidopsis Shows Phenotypes Related to Abscisic Acid Responses and Gibberellin Biosynthesis1

    Science.gov (United States)

    Reyes, David; Rodríguez, Dolores; González-García, Mary Paz; Lorenzo, Oscar; Nicolás, Gregorio; García-Martínez, José Luis; Nicolás, Carlos

    2006-01-01

    A functional abscisic acid (ABA)-induced protein phosphatase type 2C (PP2C) was previously isolated from beech (Fagus sylvatica) seeds (FsPP2C2). Because transgenic work is not possible in beech, in this study we overexpressed this gene in Arabidopsis (Arabidopsis thaliana) to provide genetic evidence on FsPP2C2 function in seed dormancy and other plant responses. In contrast with other PP2Cs described so far, constitutive expression of FsPP2C2 in Arabidopsis, under the cauliflower mosaic virus 35S promoter, produced enhanced sensitivity to ABA and abiotic stress in seeds and vegetative tissues, dwarf phenotype, and delayed flowering, and all these effects were reversed by gibberellic acid application. The levels of active gibberellins (GAs) were reduced in 35S:FsPP2C2 plants, although transcript levels of AtGA20ox1 and AtGA3ox1 increased, probably as a result of negative feedback regulation, whereas the expression of GASA1 was induced by GAs. Additionally, FsPP2C2-overexpressing plants showed a strong induction of the Responsive to ABA 18 (RAB18) gene. Interestingly, FsPP2C2 contains two nuclear targeting sequences, and transient expression assays revealed that ABA directed this protein to the nucleus. Whereas other plant PP2Cs have been shown to act as negative regulators, our results support the hypothesis that FsPP2C2 is a positive regulator of ABA. Moreover, our results indicate the existence of potential cross-talk between ABA signaling and GA biosynthesis. PMID:16815952

  3. Tree plastic bark

    OpenAIRE

    Casado Arroyo, Carlos

    2016-01-01

    Tree plastic bark" consiste en la realización de una intervención artística en un entorno natural concreto, generando de esta manera un Site Specific(1). Como hace alusión Rosalind Krauss en sus reflexiones “La escultura en el campo expandido”(2), comenta que su origen esta claramente ligado con el concepto de monumentalidad. La escultura es un monumento, se crea para conmemorar algún hecho o personaje relevante y está realizada para una ubicación concreta. La investigación parte de la id...

  4. The fault-tree compiler

    Science.gov (United States)

    Martensen, Anna L.; Butler, Ricky W.

    1987-01-01

    The Fault Tree Compiler Program is a new reliability tool used to predict the top event probability for a fault tree. Five different gate types are allowed in the fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N gates. The high level input language is easy to understand and use when describing the system tree. In addition, the use of the hierarchical fault tree capability can simplify the tree description and decrease program execution time. The current solution technique provides an answer precise (within the limits of double precision floating point arithmetic) to the five digits in the answer. The user may vary one failure rate or failure probability over a range of values and plot the results for sensitivity analyses. The solution technique is implemented in FORTRAN; the remaining program code is implemented in Pascal. The program is written to run on a Digital Corporation VAX with the VMS operation system.

  5. Large Deviations for Random Trees.

    Science.gov (United States)

    Bakhtin, Yuri; Heitsch, Christine

    2008-08-01

    We consider large random trees under Gibbs distributions and prove a Large Deviation Principle (LDP) for the distribution of degrees of vertices of the tree. The LDP rate function is given explicitly. An immediate consequence is a Law of Large Numbers for the distribution of vertex degrees in a large random tree. Our motivation for this study comes from the analysis of RNA secondary structures.

  6. Tree felling: a necessary evil

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    CERN started a campaign of tree felling in 2010 for safety reasons, and it will continue this year in various parts of the Meyrin site. As in previous years, the trees cut down in 2013 will be recycled and some will be replaced.   Diseased tree that had to be cut down on the Meyrin site. In association with the Geneva nature and countryside directorate (Direction générale de la nature et du paysage, DGNP), CERN commissioned the Geneva school of landscaping, engineering and architecture (Haute école du paysage, d’ingénierie et d’architecture, HEPIA) to compile an inventory of the trees on the Meyrin site. In total, 1285 trees (excluding poplars) were recorded. 75.5% of these trees were declared to be in a good state of health (i.e. 971 trees), 21.5% in a moderate state of health (276 trees) and 3% in a poor state of health (38 trees). As for the poplars, the 236 specimens recorded on the Meyrin site were judged to be too old, to...

  7. Human decision error (HUMDEE) trees

    International Nuclear Information System (INIS)

    Ostrom, L.T.

    1993-01-01

    Graphical presentations of human actions in incident and accident sequences have been used for many years. However, for the most part, human decision making has been underrepresented in these trees. This paper presents a method of incorporating the human decision process into graphical presentations of incident/accident sequences. This presentation is in the form of logic trees. These trees are called Human Decision Error Trees or HUMDEE for short. The primary benefit of HUMDEE trees is that they graphically illustrate what else the individuals involved in the event could have done to prevent either the initiation or continuation of the event. HUMDEE trees also present the alternate paths available at the operator decision points in the incident/accident sequence. This is different from the Technique for Human Error Rate Prediction (THERP) event trees. There are many uses of these trees. They can be used for incident/accident investigations to show what other courses of actions were available and for training operators. The trees also have a consequence component so that not only the decision can be explored, also the consequence of that decision

  8. Making CSB + -Trees Processor Conscious

    DEFF Research Database (Denmark)

    Samuel, Michael; Pedersen, Anders Uhl; Bonnet, Philippe

    2005-01-01

    Cache-conscious indexes, such as CSB+-tree, are sensitive to the underlying processor architecture. In this paper, we focus on how to adapt the CSB+-tree so that it performs well on a range of different processor architectures. Previous work has focused on the impact of node size on the performan...... a systematic method for adapting CSB+-tree to new platforms. This work is a first step towards integrating CSB+-tree in MySQL’s heap storage manager....

  9. The Steiner tree problem

    CERN Document Server

    Hwang, FK; Winter, P

    1992-01-01

    The Steiner problem asks for a shortest network which spans a given set of points. Minimum spanning networks have been well-studied when all connections are required to be between the given points. The novelty of the Steiner tree problem is that new auxiliary points can be introduced between the original points so that a spanning network of all the points will be shorter than otherwise possible. These new points are called Steiner points - locating them has proved problematic and research has diverged along many different avenues. This volume is devoted to the assimilation of the rich field of intriguing analyses and the consolidation of the fragments. A section has been given to each of the three major areas of interest which have emerged. The first concerns the Euclidean Steiner Problem, historically the original Steiner tree problem proposed by Jarník and Kössler in 1934. The second deals with the Steiner Problem in Networks, which was propounded independently by Hakimi and Levin and has enjoyed the most...

  10. Genealogy and gene trees.

    Science.gov (United States)

    Rasmuson, Marianne

    2008-02-01

    Heredity can be followed in persons or in genes. Persons can be identified only a few generations back, but simplified models indicate that universal ancestors to all now living persons have occurred in the past. Genetic variability can be characterized as variants of DNA sequences. Data are available only from living persons, but from the pattern of variation gene trees can be inferred by means of coalescence models. The merging of lines backwards in time leads to a MRCA (most recent common ancestor). The time and place of living for this inferred person can give insights in human evolutionary history. Demographic processes are incorporated in the model, but since culture and customs are known to influence demography the models used ought to be tested against available genealogy. The Icelandic data base offers a possibility to do so and points to some discrepancies. Mitochondrial DNA and Y chromosome patterns give a rather consistent view of human evolutionary history during the latest 100 000 years but the earlier epochs of human evolution demand gene trees with longer branches. The results of such studies reveal as yet unsolved problems about the sources of our genome.

  11. Distributed Merge Trees

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Dmitriy; Weber, Gunther

    2013-01-08

    Improved simulations and sensors are producing datasets whose increasing complexity exhausts our ability to visualize and comprehend them directly. To cope with this problem, we can detect and extract significant features in the data and use them as the basis for subsequent analysis. Topological methods are valuable in this context because they provide robust and general feature definitions. As the growth of serial computational power has stalled, data analysis is becoming increasingly dependent on massively parallel machines. To satisfy the computational demand created by complex datasets, algorithms need to effectively utilize these computer architectures. The main strength of topological methods, their emphasis on global information, turns into an obstacle during parallelization. We present two approaches to alleviate this problem. We develop a distributed representation of the merge tree that avoids computing the global tree on a single processor and lets us parallelize subsequent queries. To account for the increasing number of cores per processor, we develop a new data structure that lets us take advantage of multiple shared-memory cores to parallelize the work on a single node. Finally, we present experiments that illustrate the strengths of our approach as well as help identify future challenges.

  12. Occurrence of leguminous trees

    Energy Technology Data Exchange (ETDEWEB)

    Kirkbride, J.H.; Arkcoll, D.B.A.; Turnbull, J.W.; Magalhaes, L.M.S.; Fernandes, N.P.

    1984-01-01

    Five papers from the symposium are presented. Kirkbride, J.H. Jr.; Legumes of the cerrado. pp 23-46 (Refs. 55) A review is given. Some 548 legume species in 59 genera are listed that have been reported from cerrado vegetation. Felker, P.; Legume trees in semi-arid and arid areas. pp 47-59 (Refs. 41) A review is given of worldwide research activities. Arkcoll, D.B.; A comparison of some fast growing species suitable for woodlots in the wet tropics. pp 61-68 (Refs. 9) Studies are described near Manaus on intensive silviculture (for fuelwood production) of Eucalyptus deglupta, Cedrelinga catanaeformis (catenaeformis), Jacaranda copaia, and Inga edulis. Turnbull, J.W.; Six phyllodinous Acacia species for planting in the humid tropical lowlands. pp 69-73 (Refs. 14) Distribution, ecology, growth, and utilization are described for A. auriculiformis, A. mangium, A. aulacocarpa, A. crassicarpa, A. cincinnata, and A. polystachya. Magalhaes, L.M.S., Fernandes, N.P.; Experimental stands of leguminous trees in the Manaus region. pp 75-79 (Refs. 8) Performance up to age 20 yr of Cedrelinga catenaeformis, Dalbergia nigra, Dinizia excelsa, Dipteryx odorata, Dipteryx sp., Diplotropis sp., Eperua bijuga, Pithecellobium racemosum, Vouacapoua pallidior, and Hymenaea sp. is described.

  13. The radial distribution of 90Sr and 137Cs in trees

    International Nuclear Information System (INIS)

    Nomoshima, N.; Bondietti, E.A.

    1994-01-01

    The distributions of 90 Sr and 137 Cs in tree trunks were measured for eight species. The concentration of 137 Cs was relatively uniform in the wood xylem and did not show any correlation with the temporal record of cumulative deposition of fallout in the northern hemisphere, indicating that 137 Cs was mobile in the wood xylem. The distributions of 90 Sr were classified into three groups. All of the gymnosperms - red spruce, eastern hemlock and white pine - showed a maximum 90 Sr specific activity in rings formed in the 1960s and the overall distribution was closely associated with the temporal record of the cumulative deposition of fallout. Three of five angiosperms -hickory, elm and American beech - showed similar distributions to the gymnosperms except that the maximum 90 Sr specific activity corresponded to the 1970s. The other two angiosperms - yellow poplar and sugar maple - did not show any correlation with the cumulative fallout deposition. The radial distribution of 90 Sr in gymnosperms was simulated considering a steady-state cycling of 90 Sr in the forest ecosystem. The model suggested that a few per cent of stable Sr are replaced annually in the nutrient pool of gymnosperms. (Author)

  14. Visualizing Individual Tree Differences in Tree-Ring Studies

    Directory of Open Access Journals (Sweden)

    Mario Trouillier

    2018-04-01

    Full Text Available Averaging tree-ring measurements from multiple individuals is one of the most common procedures in dendrochronology. It serves to filter out noise from individual differences between trees, such as competition, height, and micro-site effects, which ideally results in a site chronology sensitive to regional scale factors such as climate. However, the climate sensitivity of individual trees can be modulated by factors like competition, height, and nitrogen deposition, calling attention to whether average chronologies adequately assess climatic growth-control. In this study, we demonstrate four simple but effective methods to visually assess differences between individual trees. Using individual tree climate-correlations we: (1 employed jitter plots with superimposed metadata to assess potential causes for these differences; (2 plotted the frequency distributions of climate correlations over time as heat maps; (3 mapped the spatial distribution of climate sensitivity over time to assess spatio-temporal dynamics; and (4 used t-distributed Stochastic Neighborhood Embedding (t-SNE to assess which trees were generally more similar in terms of their tree-ring pattern and their correlation with climate variables. This suite of exploratory methods can indicate if individuals in tree-ring datasets respond differently to climate variability, and therefore, should not solely be explored with climate correlations of the mean population chronology.

  15. Relating phylogenetic trees to transmission trees of infectious disease outbreaks.

    Science.gov (United States)

    Ypma, Rolf J F; van Ballegooijen, W Marijn; Wallinga, Jacco

    2013-11-01

    Transmission events are the fundamental building blocks of the dynamics of any infectious disease. Much about the epidemiology of a disease can be learned when these individual transmission events are known or can be estimated. Such estimations are difficult and generally feasible only when detailed epidemiological data are available. The genealogy estimated from genetic sequences of sampled pathogens is another rich source of information on transmission history. Optimal inference of transmission events calls for the combination of genetic data and epidemiological data into one joint analysis. A key difficulty is that the transmission tree, which describes the transmission events between infected hosts, differs from the phylogenetic tree, which describes the ancestral relationships between pathogens sampled from these hosts. The trees differ both in timing of the internal nodes and in topology. These differences become more pronounced when a higher fraction of infected hosts is sampled. We show how the phylogenetic tree of sampled pathogens is related to the transmission tree of an outbreak of an infectious disease, by the within-host dynamics of pathogens. We provide a statistical framework to infer key epidemiological and mutational parameters by simultaneously estimating the phylogenetic tree and the transmission tree. We test the approach using simulations and illustrate its use on an outbreak of foot-and-mouth disease. The approach unifies existing methods in the emerging field of phylodynamics with transmission tree reconstruction methods that are used in infectious disease epidemiology.

  16. TreeVector: scalable, interactive, phylogenetic trees for the web.

    Directory of Open Access Journals (Sweden)

    Ralph Pethica

    2010-01-01

    Full Text Available Phylogenetic trees are complex data forms that need to be graphically displayed to be human-readable. Traditional techniques of plotting phylogenetic trees focus on rendering a single static image, but increases in the production of biological data and large-scale analyses demand scalable, browsable, and interactive trees.We introduce TreeVector, a Scalable Vector Graphics-and Java-based method that allows trees to be integrated and viewed seamlessly in standard web browsers with no extra software required, and can be modified and linked using standard web technologies. There are now many bioinformatics servers and databases with a range of dynamic processes and updates to cope with the increasing volume of data. TreeVector is designed as a framework to integrate with these processes and produce user-customized phylogenies automatically. We also address the strengths of phylogenetic trees as part of a linked-in browsing process rather than an end graphic for print.TreeVector is fast and easy to use and is available to download precompiled, but is also open source. It can also be run from the web server listed below or the user's own web server. It has already been deployed on two recognized and widely used database Web sites.

  17. Picking a tree: habitat use by the tree agama, Acanthocercus ...

    African Journals Online (AJOL)

    We studied tree agama (Acanthocercus a. atricollis) habitat use in the Magaliesberg mountain range in northern South Africa using sightings of marked individuals, and in a few cases, radio-telemetry. Acanthocercus a. atricollis preferentially selected thorn trees (46%; Acacia karroo), followed by common sugarbush (10%; ...

  18. Urban tree database and allometric equations

    Science.gov (United States)

    E. Gregory McPherson; Natalie S. van Doorn; Paula J.  Peper

    2016-01-01

    Information on urban tree growth underpins models used to calculate the effects of trees on the environment and human well-being. Maximum tree size and other growth data are used by urban forest managers, landscape architects, and planners to select trees most suitable to the amount of growing space, thereby reducing costly future conflicts between trees and...

  19. The dependence of natural regeneration of forest trees on upper soil conditions and acidity at damaged sites in the Black Forest, Germany

    International Nuclear Information System (INIS)

    Littek, T.

    1993-06-01

    It was the goal of this study to investigate the influence of different upper soil conditions on the germination and establishment, as well as the growth, of young plants of various tree species. For this purpose, four test plots in the region of the Black Forest were laid out, in which, by various means of site preparation and fertilization, the upper soils were changed. Natural seeding of common spruce, European silver-fir, beech, sycamore maple, European mountainash, and grey alder was simulated by means of controlled sowing. For comparison, a greenhouse experiment was carried out, examining the germination and development of the same tree species in various soil substrata, using different fertilizers, and under the influence of artificial acid rain. The most important results - with a high level of variation depending on the tree species examined - can be summarized as follows: Based on the results of field and greenhouse experiments, as well as on the investigations of other authors, it can be concluded that natural regeneration of forest stands is considerably impeded under conditions of increasing soil acidity and by high acid depositions. This is seen directly as the result of unfavorable chemical conditions in the upper soil, as well as indirectly due to deteriorating competitiveness against other vegetation. Site preparation and lime or dolomite fertilization can be important measures in the practice of forestry, to encourage natural regeneration in highly acidic sites with an unfavourable humus layer and a high presence of competing vegetation. (orig./UWA). 2 figs., 85 tabs., 269 refs [de

  20. Genetic transformation of forest trees

    African Journals Online (AJOL)

    Admin

    the stress from the regeneration process. We hope that the great progress achieved in the biology of. Agrobacterium and the expression of the genes playing key role in plant development will be helpful in solving the constraint linked to the genetic transformation of forest trees. Genetic transformation of forest trees offers a ...