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Sample records for beech fagus crenata

  1. Microscopic characterization of tension wood cell walls of Japanese beech (Fagus crenata) treated with ionic liquids.

    PubMed

    Kanbayashi, Toru; Miyafuji, Hisashi

    2016-09-01

    Tension wood that is an abnormal part formed in angiosperms has been barely used for wood industry. In this study, to utilize the tension wood effectively by means of liquefaction using ionic liquid, we performed morphological and topochemical determination of the changes in tension wood of Japanese beech (Fagus crenata) during ionic liquid treatment at the cellular level using light microscopy, scanning electron microscopy and confocal Raman microscopy. Ionic liquid treatment induced cell wall swelling in tension wood. Changes in the tissue morphology treated with ionic liquids were different between normal wood and tension wood, moreover the types of ionic liquids. The ionic liquid 1-ethyl-3-methylimidazolium chloride liquefied gelatinous layers rapidly, whereas 1-ethylpyridinium bromide liquefied slowly but delignified selectively. These novel insights into the deconstruction behavior of tension wood cell walls during ionic liquid treatment provide better understanding of the liquefaction mechanism. The obtained knowledge will contribute to development of an effective chemical processing of tension wood using ionic liquids and lead to efficient use of wood resources. PMID:27285953

  2. Heterogeneous genetic structure in a Fagus crenata population in an old-growth beech forest revealed by microsatellite markers.

    PubMed

    Asuka, Y; Tomaru, N; Nisimura, N; Tsumura, Y; Yamamoto, S

    2004-05-01

    The within-population genetic structure of Fagus crenata in a 4-ha plot (200 x 200 m) of an old-growth beech forest was analysed using microsatellite markers. To assess the genetic structure, Moran's I spatial autocorrelation coefficient was calculated. Correlograms of Moran's I showed significant positive values less than 0.100 for short-distance classes, indicating weak genetic structure. The genetic structure within the population is created by limited seed dispersal, and is probably weakened by overlapping seed shadow, secondary seed dispersal, extensive pollen flow and the thinning process. Genetic structure was detected in a western subplot of 50 x 200 m with immature soils and almost no dwarf bamboos (Sasa spp.), where small and intermediate-sized individuals were distributed in aggregations with high density because of successful regeneration. By contrast, genetic structure was not found in an eastern subplot of the same size with mature soils and Sasa cover, where successful regeneration was prevented, and the density of the small and intermediate-sized individuals was low. Moreover, genetic structure of individuals in a small-size class (diameter at breast height < 12 cm) was more obvious than in a large-size class (diameter at breast height >/= 12 cm). The apparent genetic structure detected in the 4-ha plot was therefore probably the result of the structure in the western portion of the plot and in small and intermediate-sized individuals that successfully regenerated under the favourable environment. The heterogeneity in genetic structure presumably reflects variation in the density that should be affected by differences in regeneration dynamics associated with heterogeneity in environmental conditions. PMID:15078459

  3. Effect of light conditions on the resistance of current-year Fagus Crenata seedlings against fungal pathogens causing damping-off in a natural beech forest: fungus isolation and histological and chemical resistance.

    PubMed

    Ichihara, Yu; Yamaji, Keiko

    2009-09-01

    Forest gap dynamics affects light intensity on the forest floor, which in turn may influence defense and survival of tree seedlings. Current-year Fagus crenata seedlings show high mortality under the canopy caused by damping-off. In contrast, they survive pathogen attacks in gaps. However, defense mechanisms against damping-off have not been fully understood. In order to determine the resistance factors that affect mortality in current-year seedlings, we compared seedling survival and chemical and histological characteristics of the hypocotyls of seedlings from closed-stand and forest-edge plots. Damping-off occurred in the current-year seedlings mainly from the end of June to July; survival rate of the seedlings was higher in the forest-edge plot than in the closed-stand plot. By performing an inoculation test on the seedling hypocotyls, we identified Colletotrichum dematium and Cylindrocarpon sp. as the causative pathogens under low illumination only. In the beginning of July, only seedling hypocotyls from the forest-edge plot exhibited periderm formation. From mid-June to July, seedling hypocotyls from the forest-edge plot accumulated approximately twice the amount of total phenols as those accumulated by seedling hypocotyls from the closed-stand plot. The ethyl acetate phase of methanol extracts of hypocotyls showed antifungal activity. We conclude that seedlings from the forest-edge plot may resist pathogenic attack via periderm formation and increased phenol synthesis. Plant defense mechanisms that are controlled by light intensity may be important for promoting seedling regeneration in forest gap dynamics. PMID:19774414

  4. Nitrogen storage dynamics are affected by masting events in Fagus crenata.

    PubMed

    Han, Qingmin; Kabeya, Daisuke; Iio, Atsuhiro; Inagaki, Yoshiyuki; Kakubari, Yoshitaka

    2014-03-01

    It is generally assumed that the production of a large crop of seeds depletes stores of resources and that these take more than 1 year to replenish; this is accepted, theoretically, as the proximate mechanism of mast seeding (resource budget model). However, direct evidence of resource depletion in masting trees is very rare. Here, we trace seasonal and inter-annual variations in nitrogen (N) concentration and estimate the N storage pool of individuals after full masting of Fagus crenata in two stands. In 2005, a full masting year, the amount of N in fruit litter represented half of the N present in mature leaves in an old stand (age 190-260 years), and was about equivalent to the amount of N in mature leaves in a younger stand (age 83-84 years). Due to this additional burden, both tissue N concentration and individual N storage decreased in 2006; this was followed by significant replenishment in 2007, although a substantial N store remained even after full masting. These results indicate that internal storage may be important and that N may be the limiting factor for fruiting. In the 4 years following full masting, the old stand experienced two moderate masting events separated by 2 years, whilst trees in the younger stand did not fruit. This different fruiting behavior may be related to different "costs of reproduction" in the full masting year 2005, thus providing more evidence that N may limit fruiting. Compared to the non-fruiting stand, individuals in the fruiting stand exhibited an additional increase in N concentrations in roots early in the 2007 growing season, suggesting additional N uptake from the soil to supply resource demand. The enhanced uptake may alleviate the N storage depletion observed in the full masting year. This study suggests that masting affects N cycle dynamics in mature Fagus crenata and N may be one factor limiting fruiting. PMID:24221082

  5. Characteristics of water use in Fagus crenata among 3 sites throughout Japan

    NASA Astrophysics Data System (ADS)

    Tateishi, M.; Kumagai, T.; Utsumi, Y.; Suyama, Y.; Hiura, T.

    2009-12-01

    Japanese beech is widely distributed throughout Japan, and investigating adaptation of Japanese beech to the variety of atmospheric and soil water conditions is important to understand gas exchange of forest ecosystems under climate exchange. Therefore, the purpose of this study is to clarify geographical variation in control transpiration of Japanese beech trees under various climate conditions. Toward this goal, canopy stomatal conductance at tree level and hydraulic conductivity of the trees were evaluated in 3 beech stands. Stomata of beech trees with high hydraulic conductivity have high gas exchange ability, and its stomata respond to D sensitively to avoid loss more water and cavitations at high D. On the other hand, beech trees in SH have smaller hydraulic conductivity with low sensitivity to D to keep stomata opened under high D condition. The relationship between transpiration characteristics and morphological differences among sites will be discussed.

  6. Leaf litter decomposition in temperate deciduous forest stands with a decreasing fraction of beech (Fagus sylvatica)

    PubMed Central

    Jacob, Mascha; Viedenz, Karin; Polle, Andrea

    2010-01-01

    We hypothesised that the decomposition rates of leaf litter will increase along a gradient of decreasing fraction of the European beech (Fagus sylvatica) and increasing tree species diversity in the generally beech-dominated Central European temperate deciduous forests due to an increase in litter quality. We studied the decomposition of leaf litter including its lignin fraction in monospecific (pure beech) stands and in stands with up to five tree genera (Acer spp., Carpinus betulus, Fagus sylvatica, Fraxinus excelsior, Tilia spp.) using a litterbag approach. Litter and lignin decomposition was more rapid in stand-representative litter from multispecific stands than in litter from pure beech stands. Except for beech litter, the decomposition rates of species-specific tree litter did not differ significantly among the stand types, but were most rapid in Fraxinus excelsior and slowest in beech in an interspecific comparison. Pairwise comparisons of the decomposition of beech litter with litter of the other tree species (except for Acerplatanoides) revealed a “home field advantage” of up to 20% (more rapid litter decomposition in stands with a high fraction of its own species than in stands with a different tree species composition). Decomposition of stand-representative litter mixtures displayed additive characteristics, not significantly more rapid than predicted by the decomposition of litter from the individual tree species. Leaf litter decomposition rates were positively correlated with the initial N and Ca concentrations of the litter, and negatively with the initial C:N, C:P and lignin:N ratios. The results support our hypothesis that the overall decomposition rates are mainly influenced by the chemical composition of the individual litter species. Thus, the fraction of individual tree species in the species composition seems to be more important for the litter decomposition rates than tree species diversity itself. PMID:20596729

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

    PubMed

    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

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

    PubMed Central

    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

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

    PubMed

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

    2014-11-01

    To construct stomatal conductance models and estimate stomatal O3 uptake for Fagus crenata, Quercus serrata, Quercus mongolica var. crispula and Betula platyphylla, stomatal conductance (gs) was measured in seedlings of the four tree species. Better estimates of gs were made by incorporating the acute effects of O3 on gs into the models and the models could explain 34-52% of the variability in gs. Although the O3 concentration was relatively high in spring from April to May, COU of F. crenata, Q. serrata and Q. mongolica var. crispula were relatively low and the ratios of COU in spring to total COU in one year were 16.8% in all tree species because of low gs limited mainly by leaf pre-maturation and/or low temperature. The COU of B. platyphylla were relatively high mainly because of rapid leaf maturation and lower optimal temperature for stomatal opening. PMID:25150506

  10. Utilizing pigment-producing fungi to add commercial value to American beech (Fagus grandifolia).

    PubMed

    Robinson, Sara C; Tudor, Daniela; Cooper, Paul A

    2012-02-01

    American beech (Fagus grandifolia) is an abundant, underutilized tree in certain areas of North America, and methods to increase its market value are of considerable interest. This research utilized pigment-producing fungi to induce color in American beech to potentially establish its use as a decorative wood. Wood samples were inoculated with Trametes versicolor, Xylaria polymorpha, Inonotus hispidus, and Arthrographis cuboidea to induce fungal pigmentation. Black pigmentation (T. versicolor, X. polymorpha, I. hispidus) was sporadic, occurred primarily on the surfaces of the heartwood, but not internally. Pink pigmentation (A. cuboidea) occurred throughout all of the tested beech samples, but was difficult to see in the heartwood due to the darker color of the wood. To increase the visibility of the pink stain, beech blocks were pretreated with T. versicolor for 4 weeks before being inoculated with A. cuboidea. This method significantly increased the saturation of the pink stain on both beech heartwood and sapwood, creating coloration similar to that found on sugar maple. This value-adding process should be particularly effective for small-scale wood pigmentation, and should help establish a market for this currently underutilized wood species. PMID:21931972

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

    PubMed Central

    2013-01-01

    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 development in stands. Early

  12. Analysis of release cutting effects on increment and growth in Oriental beech (Fagus orientalis Lipsky) stand.

    PubMed

    Yücesan, Zafer; Ozçelik, Sevilay; Oktan, Ercan

    2015-09-01

    In the present study, the effects of release cuttings on stand structures and increment and growth relations were investigated in afforested oriental beech (Fagus orientalis Lipsky) stands. To maximize spatial variation in dataset, stratified random sampling was used to layout transects. 24 sampling plots were determined which reflects average characteristics of actual stand structure. 8 sampling plots were selected from unthinned stands, 8 sampling plots were selected from lightly thinned (19% of the total basal area removed) stand and 8 sampling plots were selected from heavily thinned (40% of the total basal area removed) stand. Light thinning was done in the year 2008 and heavy thinning in 2009. Stem analyses were carried out and pre- and post-treatment height, diameter, basal area and volume increments were examined according to thinning intensities. Obtained results showed that removal of 40% of the basal area does not contribute to stand increment and growth more positively than those in stands treated by removal of 19% of the basal area. Expected increase in height and diameter increment did not occurr post-treatment in 2008 and 2009. However, in only lightly thinned stands mean basal area increment increased after treatment. Release cuttings in beech stand needs to be practiced at least twice every 5 to 6 years, provided that peculiar characteristics of every habitat are considered. PMID:26521547

  13. Water and lipid relations in beech (Fagus sylvatica L.) seeds and its effect on storage behaviour.

    PubMed

    Pukacka, S; Hoffmann, S K; Goslar, J; Pukacki, P M; Wójkiewicz, E

    2003-04-01

    Beech (Fagus sylvatica L.) seeds indicate intermediate storage behaviour. Properties of water in seed tissues were studied to understand their requirements during storage conditions. Water sorption isotherms showed that at the same relative humidity (RH) the water content is significantly higher in embryo axes than cotyledons. This tendency maintains also after recalculating the water content for zero amount of lipids in tissues. Differential thermal analysis (DTA) indicated water crystallization exotherms in the embryo axes at moisture content (MC) higher than 29% and 16% in the cotyledons. In order to examine the occurrence of glassy state in the cytoplasm of beech embryos as a function of water content, isolated embryo axes were examined using electron spin resonance (ESR) of nitroxide TEMPO probe located inside axes cells. TEMPO molecules undergo fast reorientations with correlation time varied from 2 x 10(-9) s at 180 K to 2 x 10(-11) s at 315 K. Although the TEMPO molecules label mainly the lipid bilayers of cell membranes, they are sensitive to the dynamics and phase transformation of the cytoplasmic cell interior. The label motion is clearly affected by a transition between liquid and glassy state of the cytoplasm. The glass transition temperature (T(g)) raises from 253 to 293 K when water content decreases from 18% to 8%. Far from T(g) the motion is described by Arrhenius equation with very small activation energy E(a) in the liquid state and is relatively small in the glassy state where E(a)=1.5 kJ/mol for 28% H(2)O and E(a)=4.7 kJ/mol for 8% H(2)O or less. The optimal storage conditions of beech seeds are proposed in the range from 255 K for 15% H(2)O to 280 K for 9% H(2)O. PMID:12667610

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

    PubMed Central

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

    2015-01-01

    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. PMID:26240437

  15. Effects of long-term exposure to ammonium sulfate particles on growth and gas exchange rates of Fagus crenata, Castanopsis sieboldii, Larix kaempferi and Cryptomeria japonica seedlings

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Masahiro; Otani, Yoko; Li, Peiran; Nagao, Hiroshi; Lenggoro, I. Wuled; Ishida, Atsushi; Yazaki, Kenichi; Noguchi, Kyotaro; Nakaba, Satoshi; Yamane, Kenichi; Kuroda, Katsushi; Sano, Yuzou; Funada, Ryo; Izuta, Takeshi

    2014-11-01

    To clarify the effects of long-term exposure to ammonium sulfate (AS) particles on growth and physiological functions of forest tree species, seedlings of Fagus crenata, Castanopsis sieboldii, Larix kaempferi and Cryptomeria japonica were exposed to submicron-size AS particles during two growing seasons from 3 June 2011 to 8 October 2012. The mean sulfate concentration in PM2.5 increased during the exposure inside the chamber in 2011 and 2012 by 2.73 and 4.32 μg SO42- m-3, respectively. No significant effects of exposure to AS particles were detected on the whole-plant dry mass of the seedlings. These results indicate that the exposure to submicrometer AS particles at the ambient level for two growing seasons did not significantly affect the growth of the seedlings. No significant effects of exposure to AS particles were found on the net photosynthetic rate in the leaves or needles of F. crenata, C. sieboldii and L. kaempferi seedlings. Also, in the previous-year needles of C. japonica seedlings, exposure to AS particles significantly reduced the net photosynthetic rate, which may be caused by the reduction in the concentration of ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco). On the contrary, in current-year needles of C. japonica seedlings, net photosynthetic rate significantly increased with exposure to AS particles, which may be the result of increases in stomatal conductance and concentrations of Rubisco and chlorophyll. Furthermore, exposure to AS particles correlated with an increase in concentrations of NH4+, free amino acid and total soluble protein, suggesting that AS particles may be deliquesced, absorbed into the leaves and metabolized into amino acid and protein. These results suggest that net photosynthesis in the needles of C. japonica is relatively sensitive to submicron-size AS particles as compared with the other three tree species.

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

    NASA Astrophysics Data System (ADS)

    Cho, Moses Azong; Skidmore, Andrew K.; Sobhan, Istiak

    2009-06-01

    Estimating forest structural attributes using multispectral remote sensing is challenging because of the saturation of multispectral indices at high canopy cover. The objective of this study was to assess the utility of hyperspectral data in estimating and mapping forest structural parameters including mean diameter-at-breast height (DBH), mean tree height and tree density of a closed canopy beech forest ( Fagus sylvatica L.). Airborne HyMap images and data on forest structural attributes were collected from the Majella National Park, Italy in July 2004. The predictive performances of vegetation indices (VI) derived from all possible two-band combinations (VI ( i, j) = ( Ri - Rj)/( Ri + Rj), where Ri and Rj = reflectance in any two bands) were evaluated using calibration ( n = 33) and test ( n = 20) data sets. The potential of partial least squares (PLS) regression, a multivariate technique involving several bands was also assessed. New VIs based on the contrast between reflectance in the red-edge shoulder (756-820 nm) and the water absorption feature centred at 1200 nm (1172-1320 nm) were found to show higher correlations with the forest structural parameters than standard VIs derived from NIR and visible reflectance (i.e. the normalised difference vegetation index, NDVI). PLS regression showed a slight improvement in estimating the beech forest structural attributes (prediction errors of 27.6%, 32.6% and 46.4% for mean DBH, height and tree density, respectively) compared to VIs using linear regression models (prediction errors of 27.8%, 35.8% and 48.3% for mean DBH, height and tree density, respectively). Mean DBH was the best predicted variable among the stand parameters (calibration R2 = 0.62 for an exponential model fit and standard error of prediction = 5.12 cm, i.e. 25% of the mean). The predicted map of mean DBH revealed high heterogeneity in the beech forest structure in the study area. The spatial variability of mean DBH occurs at less than 450 m. The DBH

  17. Habitat differences influence genetic impacts of human land use on the American beech (Fagus grandifolia).

    PubMed

    Lumibao, Candice Y; McLachlan, Jason S

    2014-01-01

    Natural reforestation after regional forest clearance is a globally common land-use sequence. The genetic recovery of tree populations in these recolonized forests may depend on the biogeographic setting of the landscape, for instance whether they are in the core or in the marginal part of the species' range. Using data from 501 individuals genotyped across 7 microsatellites, we investigated whether regional differences in habitat quality affected the recovery of genetic variation in a wind-pollinated tree species, American beech (Fagus grandifolia) in Massachusetts. We compared populations in forests that were recolonized following agricultural abandonment to those in remnant forests that have only been logged in both central inland and marginal coastal regions. Across all populations in our entire study region, recolonized forests showed limited reduction of genetic diversity as only observed heterozygosity was significantly reduced in these forests (H(O) = 0.520 and 0.590, respectively). Within inland region, this pattern was observed, whereas in the coast, recolonized populations exhibited no reduction in all genetic diversity estimates. However, genetic differentiation among recolonized populations in marginal coastal habitat increased (F(st) logged = 0.072; F(st) secondary = 0.249), with populations showing strong genetic structure, in contrast to inland region. These results indicate that the magnitude of recovery of genetic variation in recolonized populations can vary at different habitats. PMID:25138571

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

    PubMed

    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

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

    PubMed Central

    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

  20. Tree Species Composition and Harvest Intensity Affect Herbivore Density and Leaf Damage on Beech, Fagus sylvatica, in Different Landscape Contexts.

    PubMed

    Mangels, Jule; Blüthgen, Nico; Frank, Kevin; Grassein, Fabrice; Hilpert, Andrea; Mody, Karsten

    2015-01-01

    Most forests are exposed to anthropogenic management activities that affect tree species composition and natural ecosystem processes. Changes in ecosystem processes such as herbivory depend on management intensity, and on regional environmental conditions and species pools. Whereas influences of specific forest management measures have already been addressed for different herbivore taxa on a local scale, studies considering effects of different aspects of forest management across different regions are rare. We assessed the influence of tree species composition and intensity of harvesting activities on arthropod herbivores and herbivore-related damage to beech trees, Fagus sylvatica, in 48 forest plots in three regions of Germany. We found that herbivore abundance and damage to beech trees differed between regions and that - despite the regional differences - density of tree-associated arthropod taxa and herbivore damage were consistently affected by tree species composition and harvest intensity. Specifically, overall herbivore damage to beech trees increased with increasing dominance of beech trees - suggesting the action of associational resistance processes - and decreased with harvest intensity. The density of leaf chewers and mines was positively related to leaf damage, and several arthropod groups responded to beech dominance and harvest intensity. The distribution of damage patterns was consistent with a vertical shift of herbivores to higher crown layers during the season and with higher beech dominance. By linking quantitative data on arthropod herbivore abundance and herbivory with tree species composition and harvesting activity in a wide variety of beech forests, our study helps to better understand the influence of forest management on interactions between a naturally dominant deciduous forest tree and arthropod herbivores. PMID:25938417

  1. Tree Species Composition and Harvest Intensity Affect Herbivore Density and Leaf Damage on Beech, Fagus sylvatica, in Different Landscape Contexts

    PubMed Central

    Mangels, Jule; Blüthgen, Nico; Frank, Kevin; Grassein, Fabrice; Hilpert, Andrea; Mody, Karsten

    2015-01-01

    Most forests are exposed to anthropogenic management activities that affect tree species composition and natural ecosystem processes. Changes in ecosystem processes such as herbivory depend on management intensity, and on regional environmental conditions and species pools. Whereas influences of specific forest management measures have already been addressed for different herbivore taxa on a local scale, studies considering effects of different aspects of forest management across different regions are rare. We assessed the influence of tree species composition and intensity of harvesting activities on arthropod herbivores and herbivore-related damage to beech trees, Fagus sylvatica, in 48 forest plots in three regions of Germany. We found that herbivore abundance and damage to beech trees differed between regions and that – despite the regional differences - density of tree-associated arthropod taxa and herbivore damage were consistently affected by tree species composition and harvest intensity. Specifically, overall herbivore damage to beech trees increased with increasing dominance of beech trees – suggesting the action of associational resistance processes – and decreased with harvest intensity. The density of leaf chewers and mines was positively related to leaf damage, and several arthropod groups responded to beech dominance and harvest intensity. The distribution of damage patterns was consistent with a vertical shift of herbivores to higher crown layers during the season and with higher beech dominance. By linking quantitative data on arthropod herbivore abundance and herbivory with tree species composition and harvesting activity in a wide variety of beech forests, our study helps to better understand the influence of forest management on interactions between a naturally dominant deciduous forest tree and arthropod herbivores. PMID:25938417

  2. Changes of photosynthetic traits in beech saplings (Fagus sylvatica) under severe drought stress and during recovery.

    PubMed

    Gallé, Alexander; Feller, Urs

    2007-11-01

    In the context of an increased risk of extreme drought events across Europe during the next decades, the capacity of trees to recover and survive drought periods awaits further attention. In summer 2005, 4-year-old beech (Fagus sylvatica L.) saplings were watered regularly or were kept for 4 weeks without irrigation in the field and then re-watered again. Changes of plant water status, leaf gas exchange and Chl a fluorescence parameters, as well as alterations in leaf pigment composition were followed. During the drought period, stomatal conductance (g(s)) and net photosynthesis (P(n)) decreased in parallel with increased water deficit. After 14 days without irrigation, stomata remained closed and P(n) was almost completely inhibited. Reversible downregulation of PSII photochemistry [the maximum quantum efficiency of PSII (F(v)/F(m))], enhanced thermal dissipation of excess excitation energy and an increased ratio of xanthophyll cycle pigments to chlorophylls (because of a loss of chlorophylls) contributed to an enhanced photo-protection in severely stressed plants. Leaf water potential was restored immediately after re-watering, while g(s), P(n) and F(v)/F(m) recovered only partially during the initial phase, even when high external CO(2) concentrations were applied during the measurements, indicating lasting non-stomatal limitations. Thereafter, P(n) recovered completely within 4 weeks, meanwhile g(s) remained permanently lower in stressed than in control plants, leading to an increased 'intrinsic water use efficiency' (P(n)/g(s)). In conclusion, although severe drought stress adversely affected photosynthetic performance of F. sylvatica (a rather drought-sensitive species), P(n) was completely restored after re-watering, presumably because of physiological and morphological adjustments (e.g. stomatal occlusions). PMID:18251880

  3. Sensitivity of red oak (Quercus rubra L.) and American beech (Fagus grandifolia Ehrh.) seedlings to sodium salts in solution culture.

    PubMed

    Thorton, F C; Schaedle, M; Raynal, D J

    1988-06-01

    Sodium salt sensitivity of red oak (Quercus rubra L.) and American beech (Fagus grandifolia Ehrh.) was evaluated in solution culture. Both species showed symptoms of salt injury when grown in the presence of less than 10 mM Na. In red oak, leaf symptoms first appeared at a sodium concentration of 6.0 mM and leaf weight was significantly reduced at 7.5 mM Na. Leaf, stem and root dry weights of American beech were significantly reduced in the presence of 4.0 mM sodium. In both species, browning of leaf margins and necrosis were evident in the Na-treated plants. The observed symptoms were associated with high concentrations of sodium in the tissues. Neither species appears to have control over sodium uptake and translocation. PMID:14972826

  4. Raman spectroscopic investigation of 13CO 2 labeling and leaf dark respiration of Fagus sylvatica L. (European beech).

    PubMed

    Keiner, Robert; Gruselle, Marie-Cécile; Michalzik, Beate; Popp, Jürgen; Frosch, Torsten

    2015-03-01

    An important issue, in times of climate change and more extreme weather events, is the investigation of forest ecosystem reactions to these events. Longer drought periods stress the vitality of trees and promote mass insect outbreaks, which strongly affect ecosystem processes and services. Cavity-enhanced Raman gas spectrometry was applied for online multi-gas analysis of the gas exchange rates of O2 and CO2 and the labeling of Fagus sylvatica L. (European beech) seedlings with (13)CO2. The rapid monitoring of all these gases simultaneously allowed for the separation of photosynthetic uptake of CO2 by the beech seedlings and a constant (12)CO2 efflux via respiration and thus for a correction of the measured (12)CO2 concentrations in course of the labeling experiment. The effects of aphid infestation with the woolly beech aphid (Phyllaphis fagi L.) as well as the effect of a drought period on the respirational gas exchange were investigated. A slightly decreased respirational activity of drought-stressed seedlings in comparison to normally watered seedlings was found already for a low drought intensity. Cavity-enhanced Raman gas monitoring of O2, (12)CO2, and (13)CO2 was proven to be a powerful new tool for studying the effect of drought stress and aphid infestation on the respirational activity of European beech seedlings as an example of important forest species in Central Europe. PMID:25577365

  5. Biotic and Abiotic Factors Controlling Respiration Rates of Above- and Belowground Woody Debris of Fagus crenata and Quercus crispula in Japan

    PubMed Central

    Jomura, Mayuko; Akashi, Yuhei; Itoh, Hiromu; Yuki, Risa; Sakai, Yoshimi; Maruyama, Yutaka

    2015-01-01

    As a large, long-term pool and source of carbon and nutrients, woody litter is an important component of forest ecosystems. The objective of this study was to estimate the effect of the factors that regulate the rate of decomposition of coarse and fine woody debris (CFWD) of dominant tree species in a cool-temperate forest in Japan. Respiration rates of dead stems, branches, and coarse and fine roots of Fagus crenata and Quercus crispula felled 4 years prior obtained in situ ranged from 20.9 to 500.1 mg CO2 [kg dry wood]–1 h–1 in a one-time measurement in summer. Respiration rate had a significant negative relationship with diameter; in particular, that of a sample of Q. crispula with a diameter of >15 cm and substantial heartwood was low. It also had a significant positive relationship with moisture content. The explanatory variables diameter, [N], wood density, and moisture content were interrelated. The most parsimonious path model showed 14 significant correlations among 8 factors and respiration. Diameter and [C] had large negative direct effects on CFWD respiration rate, and moisture content and species had medium positive direct effects. [N] and temperature did not have direct or indirect effects, and position and wood density had indirect effects. The model revealed some interrelationships between controlling factors. We discussed the influence of the direct effects of explanatory variables and the influence especially of species and position. We speculate that the small R2 value of the most parsimonious model was probably due to the omission of microbial biomass and activity. These direct and indirect effects and interrelationships between explanatory variables could be used to develop a process-based CFWD decomposition model. PMID:26658727

  6. Biotic and Abiotic Factors Controlling Respiration Rates of Above- and Belowground Woody Debris of Fagus crenata and Quercus crispula in Japan.

    PubMed

    Jomura, Mayuko; Akashi, Yuhei; Itoh, Hiromu; Yuki, Risa; Sakai, Yoshimi; Maruyama, Yutaka

    2015-01-01

    As a large, long-term pool and source of carbon and nutrients, woody litter is an important component of forest ecosystems. The objective of this study was to estimate the effect of the factors that regulate the rate of decomposition of coarse and fine woody debris (CFWD) of dominant tree species in a cool-temperate forest in Japan. Respiration rates of dead stems, branches, and coarse and fine roots of Fagus crenata and Quercus crispula felled 4 years prior obtained in situ ranged from 20.9 to 500.1 mg CO2 [kg dry wood](-1) h(-1) in a one-time measurement in summer. Respiration rate had a significant negative relationship with diameter; in particular, that of a sample of Q. crispula with a diameter of >15 cm and substantial heartwood was low. It also had a significant positive relationship with moisture content. The explanatory variables diameter, [N], wood density, and moisture content were interrelated. The most parsimonious path model showed 14 significant correlations among 8 factors and respiration. Diameter and [C] had large negative direct effects on CFWD respiration rate, and moisture content and species had medium positive direct effects. [N] and temperature did not have direct or indirect effects, and position and wood density had indirect effects. The model revealed some interrelationships between controlling factors. We discussed the influence of the direct effects of explanatory variables and the influence especially of species and position. We speculate that the small R2 value of the most parsimonious model was probably due to the omission of microbial biomass and activity. These direct and indirect effects and interrelationships between explanatory variables could be used to develop a process-based CFWD decomposition model. PMID:26658727

  7. Diversity and Composition of the Leaf Mycobiome of Beech (Fagus sylvatica) Are Affected by Local Habitat Conditions and Leaf Biochemistry

    PubMed Central

    Unterseher, Martin; Siddique, Abu Bakar; Brachmann, Andreas; Peršoh, Derek

    2016-01-01

    Comparative investigations of plant-associated fungal communities (mycobiomes) in distinct habitats and under distinct climate regimes have been rarely conducted in the past. Nowadays, high-throughput sequencing allows routine examination of mycobiome responses to environmental changes and results at an unprecedented level of detail. In the present study, we analysed Illumina-generated fungal ITS1 sequences from European beech (Fagus sylvatica) originating from natural habitats at two different altitudes in the German Alps and from a managed tree nursery in northern Germany. In general, leaf-inhabiting mycobiome diversity and composition correlated significantly with the origin of the trees. Under natural condition the mycobiome was more diverse at lower than at higher elevation, whereas fungal diversity was lowest in the artificial habitat of the tree nursery. We further identified significant correlation of leaf chlorophylls and flavonoids with both habitat parameters and mycobiome biodiversity. The present results clearly point towards a pronounced importance of local stand conditions for the structure of beech leaf mycobiomes and for a close interrelation of phyllosphere fungi and leaf physiology. PMID:27078859

  8. Diversity and Composition of the Leaf Mycobiome of Beech (Fagus sylvatica) Are Affected by Local Habitat Conditions and Leaf Biochemistry.

    PubMed

    Unterseher, Martin; Siddique, Abu Bakar; Brachmann, Andreas; Peršoh, Derek

    2016-01-01

    Comparative investigations of plant-associated fungal communities (mycobiomes) in distinct habitats and under distinct climate regimes have been rarely conducted in the past. Nowadays, high-throughput sequencing allows routine examination of mycobiome responses to environmental changes and results at an unprecedented level of detail. In the present study, we analysed Illumina-generated fungal ITS1 sequences from European beech (Fagus sylvatica) originating from natural habitats at two different altitudes in the German Alps and from a managed tree nursery in northern Germany. In general, leaf-inhabiting mycobiome diversity and composition correlated significantly with the origin of the trees. Under natural condition the mycobiome was more diverse at lower than at higher elevation, whereas fungal diversity was lowest in the artificial habitat of the tree nursery. We further identified significant correlation of leaf chlorophylls and flavonoids with both habitat parameters and mycobiome biodiversity. The present results clearly point towards a pronounced importance of local stand conditions for the structure of beech leaf mycobiomes and for a close interrelation of phyllosphere fungi and leaf physiology. PMID:27078859

  9. Transport of soluble carbohydrates in temperate deciduous trees: beech (Fagus sylvatica) and ash (Fraxinus excelsior) in comparison

    NASA Astrophysics Data System (ADS)

    Thoms, Ronny; Köhler, Michael; Gessler, Arthur; Gleixner, Gerd

    2015-04-01

    The structure of phloem cells and the physiology of the transport of soluble carbohydrates in plants are well studied. However, the influence of different phloem un- and uploading strategies on the translocation of carbohydrates in different tree species is largely unknown. Therefore, we conducted a pulse labeling on 20 young trees of European beech (Fagus sylvatica) and European ash (Fraxinus excelsior) respectively, using the stable isotope 13C in a temperate deciduous forest in Central Germany. In one growing season each tree species was labeled in a closed transparent plastic chamber with 99% 13CO2 for 5 h. The compound specific δ 13C from carbohydrates in the different compartments leaf, branch, stem and root was measured by high-performance liquid chromatography linked with an isotope ratio mass spectrometer (HPLC-IRMS). We found that both tree species used sucrose as a transport sugar, but carbohydrates of the raffinose group (RFO) served as main transport sugar in ash trees. This indicate that beech used only the apoplastic loading strategy into the phloem cells while ash trees relied on both, apoplastic and symplastic loading, preferring the latter at the end of the growing season. Furthermore, we observed different transport velocities of labeled sugars in the two species. Here, sucrose in beech and carbohydrates of the RFO in ash were transported fastest, whereas sucrose was constantly slowest in ash trees. The label of carbohydrates was found over 60 day in the roots of both tree species, with the highest δ 13C enrichment in carbohydrates of RFO than in the other sugars. Accordingly, the mean residence time (MRT) and half life time (HLT) of 13C in different compartments were longest for carbohydrates of RFO in roots (25.6 days) and sucrose in stems (14.9 days), while the shortest MRT and HLT for sucrose appeared in beech in all compartments. Our results give evidence that RFO are preferentially transported to the root tissue as an agent against frost

  10. A unigene set for European beech (Fagus sylvatica L.) and its use to decipher the molecular mechanisms involved in dormancy regulation.

    PubMed

    Lesur, Isabelle; Bechade, Alison; Lalanne, Céline; Klopp, Christophe; Noirot, Céline; Leplé, Jean-Charles; Kremer, Antoine; Plomion, Christophe; Le Provost, Grégoire

    2015-09-01

    Systematic sequencing is the method of choice for generating genomic resources for molecular marker development and candidate gene identification in nonmodel species. We generated 47,357 Sanger ESTs and 2.2M Roche-454 reads from five cDNA libraries for European beech (Fagus sylvatica L.). This tree species of high ecological and economic value in Europe is among the most representative trees of deciduous broadleaf forests. The sequences generated were assembled into 21,057 contigs with MIRA software. Functional annotations were obtained for 85% of these contigs, from the proteomes of four plant species, Swissprot accessions and the Gene Ontology database. We were able to identify 28,079 in silico SNPs for future marker development. Moreover, RNAseq and qPCR approaches identified genes and gene networks regulated differentially between two critical phenological stages preceding vegetative bud burst (the quiescent and swelling buds stages). According to climatic model-based projection, some European beech populations may be endangered, particularly at the southern and eastern edges of the European distribution range, which are strongly affected by current climate change. This first genomic resource for the genus Fagus should facilitate the identification of key genes for beech adaptation and management strategies for preserving beech adaptability. PMID:25594128

  11. Fate of recently fixed carbon in European beech (Fagus sylvatica) saplings during drought and subsequent recovery.

    PubMed

    Zang, Ulrich; Goisser, Michael; Grams, Thorsten E E; Häberle, Karl-Heinz; Matyssek, Rainer; Matzner, Egbert; Borken, Werner

    2014-01-01

    Drought reduces the carbon (C) assimilation of trees and decouples aboveground from belowground carbon fluxes, but little is known about the response of drought-stressed trees to rewetting. This study aims to assess dynamics and patterns of C allocation in beech saplings under dry and rewetted soil conditions. In October 2010, 5-year-old beech saplings from a forest site were transplanted into 20 l pots. In 2011, the saplings were subjected to different levels of soil drought ranging from non-limiting water supply (control) to severe water limitation with soil water potentials of less than -1.5 MPa. As a physiologically relevant measure of drought, the cumulated soil water potential (i.e., drought stress dose (DSD)) was calculated for the growing season. In late August, the saplings were transferred into a climate chamber and pulse-labeled with (13)C-depleted CO2 (δ(13)C of -47‰). Isotopic signatures in leaf and soil respiration were repeatedly measured. Five days after soil rewetting, a second label was applied using 99 atom% (13)CO2. After another 12 days, the fate of assimilated C in each sapling was assessed by calculating the (13)C mass balance. Photosynthesis decreased by 60% in saplings under severe drought. The mean residence time (MRT) of recent assimilates in leaf respiration was more than three times longer than under non-limited conditions and was positively correlated to DSD. Also, the appearance of the label in soil respiration was delayed. Within 5 days after rewetting, photosynthesis, MRT of recent assimilates in leaf respiration and appearance of the label in soil respiration recovered fully. Despite the fast recovery, less label was recovered in the biomass of the previously drought-stressed plants, which also allocated less C to the root compartment (45 vs 64% in the control). We conclude that beech saplings quickly recover from extreme soil drought, although transitional after-effects prevail in C allocation, possibly due to repair

  12. Impacts of drought on mineral macro- and microelements in provenances of beech (Fagus sylvatica L.) seedlings.

    PubMed

    Peuke, Andreas D; Rennenberg, Heinz

    2011-02-01

    Beech seedlings originating from 11 German provenances with different climatic conditions were grown in pots and cultivated in a greenhouse. The composition of macro- and microelements in roots, axes and leaves was measured after half of the seedlings were subjected to a simulated summer drought. The recently described sensitivity of these provenances to drought was compared with drought-mediated changes in the elemental and ionic composition in organs of the seedlings; in addition, partitioning between roots and shoots was evaluated. A number of element concentrations were decreased in roots due to drought (K 94% of control, Mg 94%, Mn 75% and Zn 85%). However, chloride concentration increased in all organs (115-125%) and was the only element affected in leaves. Some changes in ionome can be related to sensitivity of provenances, but it is difficult to decide whether these changes are a result of, or a reason for, drought tolerance or sensitivity. Observed increases in chloride concentration in all plant parts of drought-treated beech seedlings can be explained by its function in charge balance, in particular since the level of phosphate was reduced. As a result of chloride accumulation, the sum of added charges of anions (and cations) in water extracts of leaf and root material was similar between drought and control plants. Since only the partitioning of Ca and Al (both only in axis) as well as Mn was affected and other elements (together with previously observed effects on C, N, S and P) remained unaffected by drought in all provenances, it can be concluded that direct effects by means of mass flow inhibition in xylem and phloem are unlikely. Secondary effects, for example on the pH of transport sap and the apoplastic space, cannot be excluded from the present study. These effects may affect partitioning between the apoplast and symplast and therefore may be significant for drought sensitivity. PMID:21450981

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

    NASA Astrophysics Data System (ADS)

    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

  14. The production, localization and spreading of reactive oxygen species contributes to the low vitality of long-term stored common beech (Fagus sylvatica L.) seeds.

    PubMed

    Ratajczak, Ewelina; Małecka, Arleta; Bagniewska-Zadworna, Agnieszka; Kalemba, Ewa Marzena

    2015-02-01

    The common beech (Fagus sylvatica L.) is propagated by seeds, but the seed set is irregular with five to ten years in between crops. It is therefore necessary to store the seeds. However, beech seeds lose germinability during long-term storage. In this study, beech seeds were stored at -10°C under controlled conditions for 2, 5, 8, 11 and 13 years. Our results show that beech seeds lose germinability during storage in proportion to the duration of storage. The decrease in germinability correlated with increased electrolyte leakage and accumulation of superoxide anion radicals, hydrogen peroxide and hydroxyl radicals. Furthermore, a strong positive correlation was observed among the releases of superoxide anion radicals, hydrogen peroxide and hydroxyl radicals. In situ localization showed that superoxide anion radicals and hydrogen peroxide were first detectable in root cap cells. When the seed storage time was extended, the reactive oxygen species fluorescence expanded to more areas of the radicle, reaching the root apical meristem. A storage time-dependent decrease in catalase activity, observed in both embryonic axes and cotyledons, was also positively correlated with germinability. DNA fragmentation was observed in beech seeds during storage and occurred predominantly in embryonic axes stored for 5 years and more. Altogether, these results suggest that the loss of germinability in beech seeds during long-term storage depends on several factors, including strong of reactive oxygen species accumulation accompanied by reduced catalase activity as well as membrane injury and DNA alternations, which may be aging-related and ROS-derived. We suggest that the accumulating reactive oxygen species that spread to the root apical meristem are key factors that affect seed germinability after long-term storage. PMID:25462977

  15. Influence of litter chemistry and stoichiometry on glucan depolymerization during decomposition of beech (Fagus sylvatica L.) litter

    PubMed Central

    Leitner, Sonja; Wanek, Wolfgang; Wild, Birgit; Haemmerle, Ieda; Kohl, Lukas; Keiblinger, Katharina M.; Zechmeister-Boltenstern, Sophie; Richter, Andreas

    2012-01-01

    Glucans like cellulose and starch are a major source of carbon for decomposer food webs, especially during early- and intermediate-stages of decomposition. Litter quality has previously been suggested to notably influence decomposition processes as it determines the decomposability of organic material and the nutrient availability to the decomposer community. To study the impact of chemical and elemental composition of resources on glucan decomposition, a laboratory experiment was carried out using beech (Fagus sylvatica, L.) litter from four different locations in Austria, differing in composition (concentration of starch, cellulose and acid unhydrolyzable residue or AUR fraction) and elemental stoichiometry (C:N:P ratio). Leaf litter was incubated in mesocosms for six months in the laboratory under controlled conditions. To investigate the process of glucan decomposition and its controls, we developed an isotope pool dilution (IPD) assay using 13C-glucose to label the pool of free glucose in the litter, and subsequently measured the dilution of label over time. This enabled us to calculate gross rates of glucose production through glucan depolymerization, and glucose consumption by the microbial community. In addition, potential activities of extracellular cellulases and ligninases (peroxidases and phenoloxidases) were measured to identify effects of resource chemistry and stoichiometry on microbial enzyme production. Gross rates of glucan depolymerization and glucose consumption were highly correlated, indicating that both processes are co-regulated and intrinsically linked by the microbial demand for C and energy and thereby to resource allocation to enzymes that depolymerize glucans. At early stages of decomposition, glucan depolymerization rates were correlated with starch content, indicating that starch was the primary source for glucose. With progressing litter decomposition, the correlation with starch diminished and glucan depolymerization rates were

  16. Decrease in Available Soil Water Storage Capacity Reduces Vitality of Young Understorey European Beeches (Fagus sylvatica L.)—A Case Study from the Black Forest, Germany

    PubMed Central

    Chakraborty, Tamalika; Saha, Somidh; Reif, Albert

    2013-01-01

    Growth and survival of young European beech (Fagus sylvatica L.) is largely dependent on water availability. We quantified the influence of water stress (measured as Available Soil Water Storage Capacity or ASWSC) on vitality of young beech plants at a dry site. The study site was located in a semi-natural sessile oak (Quercus petraea (Mattuschka) Liebl.) stand adjacent to beech stands on a rocky gneiss outcrop in southwestern Germany. Plant vitality was measured as crown dieback and estimated by the percentage of dead above ground biomass. The magnitude of crown dieback was recorded in different vertical parts of the crown. Biomass was calculated from the harvested plants following allometric regression equations specifically developed for our study site. Stem discs from harvested plants were used for growth analysis. We found that soil depth up to bedrock and skeleton content significantly influenced ASWSC at the study site. A significant negative correlation between ASWSC and crown dieback was found. Highest rates of crown dieback were noticed in the middle and lower crown. The threshold of crown dieback as a function of drought stress for young beech plants was calculated for the first time in this study. This threshold of crown dieback was found to be 40% of above ground biomass. Beyond 40% crown dieback, plants eventually experienced complete mortality. In addition, we found that the extremely dry year of 2003 significantly hampered growth (basal area increment) of plants in dry plots (ASWSC < 61 mm) in the study area. Recovery in the plants’ radial growth after that drought year was significantly higher in less dry plots (ASWSC > 61 mm) than in dry plots. We concluded that a decrease in ASWSC impeded the vitality of young beech causing partial up to complete crown dieback in the study site. PMID:27137398

  17. Seasonal dynamics of δ(13) C of C-rich fractions from Picea abies (Norway spruce) and Fagus sylvatica (European beech) fine roots.

    PubMed

    Paya, Alex M; Grams, Thorsten E E; Bauerle, Taryn L

    2016-09-01

    The (13/12) C ratio in plant roots is likely dynamic depending on root function (storage versus uptake), but to date, little is known about the effect of season and root order (an indicator of root function) on the isotopic composition of C-rich fractions in roots. To address this, we monitored the stable isotopic composition of one evergreen (Picea abies) and one deciduous (Fagus sylvatica), tree species' roots by measuring δ(13) C of bulk, respired and labile C, and starch from first/second and third/fourth order roots during spring and fall root production periods. In both species, root order differences in δ(13) C were observed in bulk organic matter, labile, and respired C fractions. Beech exhibited distinct seasonal trends in δ(13) C of respired C, while spruce did not. In fall, first/second order beech roots were significantly depleted in (13) C, whereas spruce roots were enriched compared to higher order roots. Species variation in δ (13) C of respired C may be partially explained by seasonal shifts from enriched to depleted C substrates in deciduous beech roots. Regardless of species identity, differences in stable C isotopic composition of at least two root order groupings (first/second, third/fourth) were apparent, and should hereafter be separated in belowground C-supply-chain inquiry. PMID:27155532

  18. Impact of elevated atmospheric O3 on the actinobacterial community structure and function in the rhizosphere of European beech (Fagus sylvatica L.)

    PubMed Central

    Haesler, Felix; Hagn, Alexandra; Engel, Marion; Schloter, Michael

    2014-01-01

    Many bacteria belonging to the phylum of Actinobacteria are known as antagonists against phytpathogenic microbes. This study aimed to analyze the effect of ozone on the actinobacterial community of the rhizosphere of four years old European beech (Fagus sylvatica L.) trees during different time points of the vegetation period. Effects of ozone on the total community structure of Actinobacteria were studied based on the analysis of 16S rRNA gene amplicons. In addition effects of the ozone treatment on the diversity of potential biocontrol active Actionobacteria being able to produce antibiotics were characterized by using the type II polyketide synthases (PKS) genes as marker. Season as well as ozone treatments had a significant effect on parts of the actinobacterial rhizosphere community of European beech. However on the basis of the performed analysis, the diversity of Actinobacteria possessing type II PKS genes is neither affected by seasonal changes nor by the ozone treatments, indicating no influence of the investigated treatments on the biocontrol active part of the actinobacterial community. PMID:24575080

  19. Assessment of spatial discordance of primary and effective seed dispersal of European beech (Fagus sylvatica L.) by ecological and genetic methods.

    PubMed

    Millerón, M; López de Heredia, U; Lorenzo, Z; Alonso, J; Dounavi, A; Gil, L; Nanos, N

    2013-03-01

    Spatial discordance between primary and effective dispersal in plant populations indicates that postdispersal processes erase the seed rain signal in recruitment patterns. Five different models were used to test the spatial concordance of the primary and effective dispersal patterns in a European beech (Fagus sylvatica) population from central Spain. An ecological method was based on classical inverse modelling (SSS), using the number of seed/seedlings as input data. Genetic models were based on direct kernel fitting of mother-to-offspring distances estimated by a parentage analysis or were spatially explicit models based on the genotype frequencies of offspring (competing sources model and Moran-Clark's Model). A fully integrated mixed model was based on inverse modelling, but used the number of genotypes as input data (gene shadow model). The potential sources of error and limitations of each seed dispersal estimation method are discussed. The mean dispersal distances for seeds and saplings estimated with these five methods were higher than those obtained by previous estimations for European beech forests. All the methods show strong discordance between primary and effective dispersal kernel parameters, and for dispersal directionality. While seed rain was released mostly under the canopy, saplings were established far from mother trees. This discordant pattern may be the result of the action of secondary dispersal by animals or density-dependent effects; that is, the Janzen-Connell effect. PMID:23379310

  20. Ectomycorrhizal Communities on the Roots of Two Beech (Fagus sylvatica) Populations from Contrasting Climates Differ in Nitrogen Acquisition in a Common Environment.

    PubMed

    Leberecht, Martin; Dannenmann, Michael; Gschwendtner, Silvia; Bilela, Silvija; Meier, Rudolf; Simon, Judy; Rennenberg, Heinz; Schloter, Michael; Polle, Andrea

    2015-09-01

    Beech (Fagus sylvatica), a dominant forest species in Central Europe, competes for nitrogen with soil microbes and suffers from N limitation under dry conditions. We hypothesized that ectomycorrhizal communities and the free-living rhizosphere microbes from beech trees from sites with two contrasting climatic conditions exhibit differences in N acquisition that contribute to differences in host N uptake and are related to differences in host belowground carbon allocation. To test these hypotheses, young trees from the natural regeneration of two genetically similar populations, one from dryer conditions (located in an area with a southwest exposure [SW trees]) and the other from a cooler, moist climate (located in an area with a northeast exposure [NE trees]), were transplanted into a homogeneous substrate in the same environment and labeled with (13)CO2 and (15)NH4 (+). Free-living rhizosphere microbes were characterized by marker genes for the N cycle, but no differences between the rhizospheres of SW or NE trees were found. Lower (15)N enrichment was found in the ectomycorrhizal communities of the NE tree communities than the SW tree communities, whereas no significant differences in (15)N enrichment were observed for nonmycorrhizal root tips of SW and NE trees. Neither the ectomycorrhizal communities nor the nonmycorrhizal root tips originating from NE and SW trees showed differences in (13)C signatures. Because the level of (15)N accumulation in fine roots and the amount transferred to leaves were lower in NE trees than SW trees, our data support the suggestion that the ectomycorrhizal community influences N transfer to its host and demonstrate that the fungal community from the dry condition was more efficient in N acquisition when environmental constraints were relieved. These findings highlight the importance of adapted ectomycorrhizal communities for forest nutrition in a changing climate. PMID:26092464

  1. Interaction Effect between Elevated CO₂ and Fertilization on Biomass, Gas Exchange and C/N Ratio of European Beech (Fagus sylvatica L.).

    PubMed

    Lotfiomran, Neda; Köhl, Michael; Fromm, Jörg

    2016-01-01

    The effects of elevated CO₂ and interaction effects between elevated CO₂ and nutrient supplies on growth and the C/N ratio of European beech (Fagus sylvatica L.) saplings were studied. One-year-old beech saplings were grown in a greenhouse at ambient (385 ppm) and elevated CO₂ (770 ppm/950 ppm), with or without fertilization for two growing seasons. In this study, emphasis is placed on the combined fertilization including phosphorus, potassium and nitrogen with two level of elevated CO₂. The fertilized plants grown under elevated CO₂ had the highest net leaf photosynthesis rate (Ac). The saplings grown under elevated CO₂ had a significantly lower stomatal conductance (gs) than saplings grown under ambient air. No interaction effect was found between elevated CO₂ and fertilization on Ac. A interaction effect between CO₂ and fertilization, as well as between date and fertilization and between date and CO₂ was detected on gs. Leaf chlorophyll content index (CCI) and leaf nitrogen content were strongly positively correlated to each other and both of them decreased under elevated CO₂. At the end of both growing seasons, stem dry weight was greater under elevated CO₂ and root dry weight was not affected by different treatments. No interaction effect was detected between elevated CO₂ and nutrient supplies on the dry weight of different plant tissues (stems and roots). However, elevated CO₂ caused a significant decrease in the nitrogen content of plant tissues. Nitrogen reduction in the leaves under elevated CO₂ was about 10% and distinctly higher than in the stem and root. The interaction effect of elevated CO₂ and fertilization on C/N ratio in plants tissues was significant. The results led to the conclusion that photosynthesis and the C/N ratio increased while stomatal conductance and leaf nitrogen content decreased under elevated CO₂ and nutrient-limited conditions. In general, under nutrient-limited conditions, the plant responses to

  2. Ectomycorrhizal Communities on the Roots of Two Beech (Fagus sylvatica) Populations from Contrasting Climates Differ in Nitrogen Acquisition in a Common Environment

    PubMed Central

    Leberecht, Martin; Dannenmann, Michael; Gschwendtner, Silvia; Bilela, Silvija; Meier, Rudolf; Simon, Judy; Rennenberg, Heinz; Schloter, Michael

    2015-01-01

    Beech (Fagus sylvatica), a dominant forest species in Central Europe, competes for nitrogen with soil microbes and suffers from N limitation under dry conditions. We hypothesized that ectomycorrhizal communities and the free-living rhizosphere microbes from beech trees from sites with two contrasting climatic conditions exhibit differences in N acquisition that contribute to differences in host N uptake and are related to differences in host belowground carbon allocation. To test these hypotheses, young trees from the natural regeneration of two genetically similar populations, one from dryer conditions (located in an area with a southwest exposure [SW trees]) and the other from a cooler, moist climate (located in an area with a northeast exposure [NE trees]), were transplanted into a homogeneous substrate in the same environment and labeled with 13CO2 and 15NH4+. Free-living rhizosphere microbes were characterized by marker genes for the N cycle, but no differences between the rhizospheres of SW or NE trees were found. Lower 15N enrichment was found in the ectomycorrhizal communities of the NE tree communities than the SW tree communities, whereas no significant differences in 15N enrichment were observed for nonmycorrhizal root tips of SW and NE trees. Neither the ectomycorrhizal communities nor the nonmycorrhizal root tips originating from NE and SW trees showed differences in 13C signatures. Because the level of 15N accumulation in fine roots and the amount transferred to leaves were lower in NE trees than SW trees, our data support the suggestion that the ectomycorrhizal community influences N transfer to its host and demonstrate that the fungal community from the dry condition was more efficient in N acquisition when environmental constraints were relieved. These findings highlight the importance of adapted ectomycorrhizal communities for forest nutrition in a changing climate. PMID:26092464

  3. Differential radial growth patterns between beech (Fagus sylvatica L.) and oak (Quercus robur L.) on periodically waterlogged soils.

    PubMed

    Scharnweber, Tobias; Manthey, Michael; Wilmking, Martin

    2013-04-01

    Climate scenarios for northern Central Europe project rising temperatures and increasing frequency and intensity of droughts but also a shift in precipitation pattern with more humid winters. This in turn may result in soil waterlogging during the following spring, leading to increasing stress for trees growing on hydric sites. The influence of waterlogging on growth of common beech and pedunculate oak has been studied intensively on seedlings under experimental conditions. However, the question remains whether results of these studies can be transferred to mature trees growing under natural conditions. To test this, we investigated general growth patterns and climate-growth relationships in four mature stands of beech and oak growing on hydromorphic soils (Stagnosols) in northeast Germany using dendrochronological methods. Our results confirmed the expected tolerance of oak to strong water-level fluctuations. Neither extremely wet conditions during spring nor summer droughts significantly affected its radial growth. Oak growth responded positively to warmer temperatures during previous year October and March of the current year of ring formation. Contrary to our expectations, also beech showed relatively low sensitivity to periods of high soil water saturation. Instead, summer drought turned out to be the main climatic factor influencing ring width of beech even under the specific periodically wet soil conditions of our study. This became evident from general climate-growth correlations over the last century as well as from discontinuous (pointer year) analysis with summer drought being significantly correlated to the occurrence of growth depressions. As ring width of the two species is affected by differing climate parameters, species-specific chronologies show no coherence in high-frequency variations even for trees growing in close proximity. We assume differences in rooting depth as the main reason for the differing growth patterns and climate correlations of

  4. Age-related changes in protein metabolism of beech (Fagus sylvatica L.) seeds during alleviation of dormancy and in the early stage of germination.

    PubMed

    Ratajczak, Ewelina; Kalemba, Ewa M; Pukacka, Stanislawa

    2015-09-01

    The long-term storage of seeds generally reduces their viability and vigour. The aim of this work was to evaluate the effect of long-term storage on beech (Fagus sylvatica L.) seeds at optimal conditions, over 9 years, on the total and soluble protein levels and activity of proteolytic enzymes, including endopeptidases, carboxypeptidases and aminopeptidases, as well as free amino acid levels and protein synthesis, in dry seeds, after imbibition and during cold stratification leading to dormancy release and germination. The same analyses were conducted in parallel on seeds gathered from the same tree in the running growing season and stored under the same conditions for only 3 months. The results showed that germination capacity decreased from 100% in freshly harvested seeds to 75% in seeds stored for 9 years. The levels of total and soluble proteins were highest in freshly harvested seeds and decreased significantly during storage, these proportions were retained during cold stratification and germination of seeds. Significant differences between freshly harvested and stored seeds were observed in the activities of proteolytic enzymes, including endopeptidases, aminopeptidases and carboxypeptidases, and in the levels of free amino acids. The neosynthesis of proteins during dormancy release and in the early stage of seed germination was significantly weaker in stored seeds. These results confirm the importance of protein metabolism for seed viability and the consequences of its reduction during seed ageing. PMID:26071872

  5. Harvesting impact on herbaceous understory, forest floor and top soil properties on skid road in a beech (Fagus orientalis Lipsky) stand.

    PubMed

    Demir, Murat; Makineci, E; Yilmaz, E

    2007-04-01

    In this study the impact of production work on the skid roads that have been carried out for many years by manpower animal power or machinery in a beech (Fagus orientalis Lipsky) stand have been examined. For this purpose, herbaceous understory, forest floor and soil samples were collected from the undisturbed area and the skid road. Weight per unit area (kg ha(-1)), organic matter ratio and moisture of forest floor and herbaceous understory were measured in undisturbed area and the skid road. Soil characteristics were examined at two different depths (0-5 cm and 5-10 cm). Percentages of sand, silt and clay electrical conductivity, weight of fine soil (<2 mm), soil fraction (>2 mm), root mass, organic carbon, moisture equivalent, total porosity, bulk density, moisture, compaction and pH values in the soil were determined. It has been determined that the amount of herbaceous understory and forest floor on the skid road decreased considerably compared to those of the undisturbed area. Parallel to this, the amount of organic matter in the herbaceous understory and the forest floor on the skid road decreased as well. It has been concluded that there are crucial differences between the values of compaction, bulk density fine soil weight, total porosity and moisture equivalent of the soil samples collected from both the skid road and the undisturbed area at both depth levels, as a result of compaction of the soil caused by harvesting works. PMID:17929761

  6. Effects of drought and canopy ozone exposure on antioxidants in fine roots of mature European beech (Fagus sylvatica).

    PubMed

    Haberer, Kristine; Herbinger, Karin; Alexou, Maria; Rennenberg, Heinz; Tausz, Michael

    2008-05-01

    We quantified ascorbate, glutathione and alpha-tocopherol in fine roots of mature Fagus sylvatica L. under free-air canopy ozone (O(3)) exposure (twice ambient O(3) concentration, 2x[O(3)]) during two growing seasons that differed in the extent of summer drought (exceptional drought year 2003, average year 2004). This design allowed us to test whether O(3) exposure or drought, or both, affected root antioxidants during the growing season. In both years, root ascorbate and alpha-tocopherol showed a similar relationship with volumetric soil water content (SWC): ascorbate concentrations on a root dry mass basis increased from about 6 to 12 micromol g(-1) when SWC dropped from 25 to 20%, and a-tocopherol increased from 100 to 150 nmol g(-1) at SWC values below 20%. Root glutathione showed no relationship with SWC or differences between the dry and the average year, but it was significantly and consistently diminished by 2x[O(3)]. Our results were inconclusive as to whether shoot-root translocation of glutathione or glutathione production in the roots was diminished. Phloem glutathione concentrations in the canopy remained constant, but reduced transport velocity in the phloem and, as a consequence, reduced mass flow of glutathione cannot be ruled out. PMID:18316303

  7. Does reduced precipitation trigger physiological and morphological drought adaptations in European beech (Fagus sylvatica L.)? Comparing provenances across a precipitation gradient.

    PubMed

    Knutzen, Florian; Meier, Ina Christin; Leuschner, Christoph

    2015-09-01

    Global warming and associated decreases in summer rainfall may threaten tree vitality and forest productivity in many regions of the temperate zone in the future. One option for forestry to reduce the risk of failure is to plant genotypes which combine high productivity with drought tolerance. Growth experiments with provenances from different climates indicate that drought exposure can trigger adaptive drought responses in temperate trees, but it is not well known whether and to what extent regional precipitation reduction can increase the drought resistance of a species. We conducted a common garden growth experiment with five European beech (Fagus sylvatica L.) populations from a limited region with pronounced precipitation heterogeneity (816-544 mm year(-1)), where phylogenetically related provenances grew under small to large water deficits. We grew saplings of the five provenances at four soil moisture levels (dry to moist) and measured ∼30 morphological (leaf and root properties, root : shoot ratio), physiological (leaf water status parameters, leaf conductance) and growth-related traits (above- and belowground productivity) with the aim to examine provenance differences in the drought response of morphological and physiological traits and to relate the responsiveness to precipitation at origin. Physiological traits were more strongly influenced by provenance (one-third of the studied traits), while structural traits were primarily affected by water availability in the experiment (two-thirds of the traits). The modulus of leaf tissue elasticity ϵ reached much higher values late in summer in plants from moist origins resulting in more rapid turgor loss and a higher risk of hydraulic failure upon drought. While experimental water shortage affected the majority of morphological and productivity-related traits in the five provenances, most parameters related to leaf water status were insensitive to water shortage. Thus, plant morphology, and root

  8. Patterns of late spring frost leaf damage and recovery in a European beech (Fagus sylvatica L.) stand in south-eastern Germany based on repeated digital photographs

    PubMed Central

    Menzel, Annette; Helm, Raimund; Zang, Christian

    2015-01-01

    Damage by late spring frost is a risk deciduous trees have to cope with in order to optimize the length of their growing season. The timing of spring phenological development plays a crucial role, not only at the species level, but also at the population and individual level, since fresh new leaves are especially vulnerable. For the pronounced late spring frost in May 2011 in Germany, we studied the individual leaf development of 35 deciduous trees (mainly European beech Fagus sylvatica L.) at a mountainous forest site in the Bayerischer Wald National Park using repeated digital photographs. Analyses of the time series of greenness by a novel Bayesian multiple change point approach mostly revealed five change points which almost perfectly matched the expected break points in leaf development: (i) start of the first greening between day of the year (DOY) 108–119 (mean 113), (ii) end of greening, and (iii) visible frost damage after the frost on the night of May 3rd/4th (DOY 123/124), (iv) re-sprouting 19–38 days after the frost, and (v) full maturity around DOY 178 (166–184) when all beech crowns had fully recovered. Since frost damage was nearly 100%, individual susceptibility did not depend on the timing of first spring leaf unfolding. However, we could identify significant patterns in fitness linked to an earlier start of leaf unfolding. Those individuals that had an earlier start of greening during the first flushing period had a shorter period of recovery and started the second greening earlier. Thus, phenological timing triggered the speed of recovery from such an extreme event. The maximum greenness achieved, however, did not vary with leaf unfolding dates. Two mountain ashes (Sorbus aucuparia L.) were not affected by the low temperatures of -5°C. Time series analysis of webcam pictures can thus improve process-based knowledge and provide valuable insights into the link between phenological variation, late spring frost damage, and recovery within one

  9. Patterns of late spring frost leaf damage and recovery in a European beech (Fagus sylvatica L.) stand in south-eastern Germany based on repeated digital photographs

    NASA Astrophysics Data System (ADS)

    Menzel, Annette; Helm, Raimund; Zang, Christian

    2015-04-01

    The seasonality of woody plants in cold and temperate climates is adapted to the annual course of temperature and photoperiod in order to maximise the length of the active growing season and, at the same time, avoid damages by frost events, especially by late spring frosts. Winter chilling, spring warming and finally photoperiod trigger the timely bud burst of European beech (Fagus sylvatica L.) which as a climax species is quite sensitive to winter frost and also as seedling to late spring frosts. However, due to relatively late and less varying dates of leaf unfolding, damages by late spring frosts should not occur each year. In case of a total loss due to a late frost event, F. sylvatica trees produce a new set of leaves which guarantees survival, but diminishes carbon reserves. With a phenological camera we observed the phenological course of such an extreme event in the Nationalpark Bayerischer Wald in May 2011: Spring leaf unfolding, an almost complete loss of fresh green leaves after the frost event in the night 3rd to 4th May, a subsequent leafless period followed by re-sprouting. We modeled this special leaf development from day 80 to 210, observed as green% from the repeated digital camera pictures, using the Bayesian multiple change point approach recently introduced by Henneken et al. (2013). The results for more than 30 trees predominantly suggested a model with five change points: firstly, start of the season, abrupt ending before the frost event, the loss by the frost event and after a longer period of recovery the second leaf unfolding (St. John's sprout) ending in full leaf maturity. Analyzing the results of these models the following questions were answered (1) how long is the period of recovery till the second green-up? (2) does the temporal course of the second leafing differ from the first one? (3) what are the individual factors influencing damage and recovery? (4) are individuals with early or late bud burst more prone to damage? The five

  10. Patterns of late spring frost leaf damage and recovery in a European beech (Fagus sylvatica L.) stand in south-eastern Germany based on repeated digital photographs.

    PubMed

    Menzel, Annette; Helm, Raimund; Zang, Christian

    2015-01-01

    Damage by late spring frost is a risk deciduous trees have to cope with in order to optimize the length of their growing season. The timing of spring phenological development plays a crucial role, not only at the species level, but also at the population and individual level, since fresh new leaves are especially vulnerable. For the pronounced late spring frost in May 2011 in Germany, we studied the individual leaf development of 35 deciduous trees (mainly European beech Fagus sylvatica L.) at a mountainous forest site in the Bayerischer Wald National Park using repeated digital photographs. Analyses of the time series of greenness by a novel Bayesian multiple change point approach mostly revealed five change points which almost perfectly matched the expected break points in leaf development: (i) start of the first greening between day of the year (DOY) 108-119 (mean 113), (ii) end of greening, and (iii) visible frost damage after the frost on the night of May 3rd/4th (DOY 123/124), (iv) re-sprouting 19-38 days after the frost, and (v) full maturity around DOY 178 (166-184) when all beech crowns had fully recovered. Since frost damage was nearly 100%, individual susceptibility did not depend on the timing of first spring leaf unfolding. However, we could identify significant patterns in fitness linked to an earlier start of leaf unfolding. Those individuals that had an earlier start of greening during the first flushing period had a shorter period of recovery and started the second greening earlier. Thus, phenological timing triggered the speed of recovery from such an extreme event. The maximum greenness achieved, however, did not vary with leaf unfolding dates. Two mountain ashes (Sorbus aucuparia L.) were not affected by the low temperatures of -5°C. Time series analysis of webcam pictures can thus improve process-based knowledge and provide valuable insights into the link between phenological variation, late spring frost damage, and recovery within one stand

  11. Use of thermal imaging to determine leaf conductance along a canopy gradient in European beech (Fagus sylvatica).

    PubMed

    Reinert, Stefan; Bögelein, Rebekka; Thomas, Frank M

    2012-03-01

    Using an infrared camera, we measured the leaf temperature across different canopy positions of a 23-m-tall deciduous forest tree (Fagus sylvatica L.) including typical sun and shade leaves as well as intermediate leaf forms, which differed significantly in specific leaf area (SLA). We calculated a temperature index (I(G)) and a crop water stress index (CWSI) using the surface temperatures of wet and dry reference leaves. Additional indices were computed using air temperature plus 5 °C (I(G) + 5, CWSI + 5) as dry references. The minimum temperature of the wet leaf and the maximum temperature of the dry leaf proved to be most suitable as reference values. We correlated the temperature indices with leaf area-related conductance to water vapor (g(L)) using porometry at the leaf level and using xylem sap flow at the branch level. At the leaf and at the branch level, I(G) and CWSI were equally well suited as proxies of g(L), whereas the relationships of I(G) + 5 and CWSI + 5 with g(L) were only weak or even insignificant. At the leaf level, the correlations of I(G) and CWSI with g(L) were significant in all parts of the crown. The slopes of g(L) vs. I(G) and CWSI did not differ significantly among the crown parts; this indicates that they were not influenced by SLA or irradiance. At the branch level, close correlations (r > 0.8) were found between temperature indices and g(L) across the crown. These results demonstrate that satisfactory relationships between temperature indices and g(L) can be established in tall trees even in those canopy parts that are exposed to relatively low levels of irradiance and exhibit relatively low values of g(L). PMID:22427372

  12. Unraveling carbohydrate transport mechanisms in young beech trees (Fagus sylvatica f. purpurea) by 13CO2 efflux measurements from stem and soil

    NASA Astrophysics Data System (ADS)

    Thoms, Ronny; Muhr, Jan; Keitel, Claudia; Kayler, Zachary; Gavrichkova, Olga; Köhler, Michael; Gessler, Arthur; Gleixner, Gerd

    2016-04-01

    Transport mechanisms of soluble carbohydrates and diurnal CO2 efflux from tree stems and surrounding soil are well studied. However, the effect of transport carbohydrates on respiration and their interaction with storage processes is largely unknown. Therefore, we performed a set of 13CO2 pulse labeling experiments on young trees of European beech (Fagus sylvatica f. purpurea). We labeled the whole tree crowns in a closed transparent plastic chamber with 99% 13CO2 for 30 min. In one experiment, only a single branch was labeled and removed 36 hours after labeling. In all experiments, we continuously measured the 13CO2 efflux from stem, branch and soil and sampled leaf and stem material every 3 h for 2 days, followed by a daily sampling of leaves in the successive 5 days. The compound specific δ 13C value of extracted soluble carbohydrates from leaf and stem material was measured by high-performance liquid chromatography linked with an isotope ratio mass spectrometer (HPLC-IRMS). The 13CO2 signal from soil respiration occurred only few hours after labeling indicating a very high transport rate of carbohydrates from leaf to roots and to the rhizosphere. The label was continuously depleted within the next 5 days. In contrast, we observed a remarkable oscillating pattern of 13CO2 efflux from the stem with maximum 13CO2 enrichment at noon and minima at night time. This oscillation suggests that enriched carbohydrates are respired during the day, whereas in the night the enriched sugars are not respired. The observed oscillation in stem 13CO2 enrichment remained unchanged even when only single branches were labelled and cut right afterwards. Thus, storage and conversion of carbohydrates only occurred within the stem. The δ13C patterns of extracted soluble carbohydrates showed, that a transformation of transitory starch to carbohydrates and vice versa was no driver of the oscillating 13CO2 efflux from the stem. Carbohydrates might have been transported in the phloem to

  13. Impacts of repeated timber skidding on the chemical properties of topsoil, herbaceous cover and forest floor in an eastern beech (Fagus orientalis Lipsky) stand.

    PubMed

    Demir, Murat; Makineci, Ender; Comez, Aydin; Yilmaz, Ersel

    2010-07-01

    In this study, long-term timber skidding effects on herbaceous understory forest floor and soil were investigated on a skid road in a stand of the eastern beech (Fagus orientalis Lipsky). For this purpose, herbaceous understory forest floor and soil samples were collected from the skid road and from an undisturbed area used as a control plot. The mass (kg ha(-1)) of herbaceous and forest floor samples was determined, and soil characteristics were examined at two depths (0-5 cm and 5-10 cm). We quantified sand, silt and clay content, as well as bulk density compaction, pH, and organic carbon content in soil samples. The quantities of N, K, P, Na, Ca, Mg, Fe, Mn, Zn and Cu were determined in all herbaceous cover forest floor and soil samples. The quantities of Na, Fe, Zn, Cu and Mn in herbaceous understory samples from the skid road were considerably higher than those in the undisturbed area, while the quantity of Mg was considerably lower. These differences could have been caused by decreased herbaceous cover in addition to variations in the properties of the forest floor and soil after skidding. A lower amount of forest floor on the skid road was the result of skidding and harvesting activities. Mg and Zn contents in forest floor samples were found to be considerably lower for the skid road than for the undisturbed area. No significant differences were found in soil chemical properties (quantities of N, P, K, Na, Ca, Mg, Fe, Zn, Cu and Mn) at the 0-5 cm soil depth. Important differences exist between soil quantities of Mg at a 5-10 cm depth on the skid road and in undisturbed areas. Both 0-5 cm and 5-10 cm soil depths, the average penetrometer resistance values for the skid road was higher than for the undisturbed area. This result shows that the compaction caused by skidding is maintained to depth of 10 cm. Skid road soil showed higher bulk density values than undisturbed areas because of compaction. PMID:21186723

  14. Below-ground effects of enhanced tropospheric ozone and drought in a beech/spruce forest (Fagus sylvatica L. / Picea abies [L.] Karst)

    EPA Science Inventory

    The effects of experimentally elevated O3 on soil respiration rates, standing fine-root biomass, fine-root production and δ13C signature of newly produced fine roots were investigated in an adult European beech/Norway spruce forest in Germany during two subsequent years with cont...

  15. Carbon isotopic composition and oxygen isotopic enrichment in phloem and total leaf organic matter of European beech (Fagus sylvatica L.) along a climate gradient.

    PubMed

    Keitel, Claudia; Matzarakis, Andreas; Rennenberg, Heinz; Gessler, Arthur

    2006-08-01

    This study investigated the influence of climate on the carbon isotopic composition (sigma13C) and oxygen isotopic enrichment (delta18O) above the source water of different organic matter pools in European beech. In July and September 2002, sigma13C and delta18O were determined in phloem carbohydrates and in bulk foliage of adult beech trees along a transect from central Germany to southern France, where beech reaches its southernmost distributional limit. The data were related to meteorological and physiological parameters. The climate along the transect stretches from temperate [subcontinental (SC)] to submediterranean (SM). Both sigma13Cleaf and delta18Oleaf were representative of site-specific long-term environmental conditions. sigma13C of leaves collected in September was indicative of stomatal conductance, vapour pressure deficit (VPD) and radiation availability of the current growing season. delta18O was mainly correlated to mean growing season relative humidity (RH) and VPD. In contrast to the leaves, sigma13Cphloem varied considerably between July and September and was well correlated with canopy stomatal conductance (Gs) in a 2 d integral prior to phloem sampling. The relationship between sigma13C and delta18O in both leaves and phloem sap points, however, to a combined influence of stomatal conductance and photosynthetic capacity on the variation of sigma13C along the transect. delta18Ophloem could be described by applying a model that included 18O fractionation associated with water exchange between the leaf and the atmosphere and with the production of organic matter. Hence, isotope signatures can be used as effective tools to assess the water balance of beech, and thus, help predict the effects of climatic change on one of the ecologically and economically most important tree species in Central Europe. PMID:16898013

  16. Detection, quantification and modelling of small-scale lateral translocation of throughfall in tree crowns of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.)

    NASA Astrophysics Data System (ADS)

    Frischbier, Nico; Wagner, Sven

    2015-03-01

    The redistribution of precipitation in forests depends on the amount of above-canopy precipitation and is characterised by high small-scale variability. Although higher and lower values of net forest precipitation at small scales are typically averaged at larger spatial scales, the small-scale variability of throughfall needs to be understood because subordinate ecological processes in the forest ecosystem, e.g., regeneration of tree species, often take place at the same small scale. High stemflow amounts and canopy driplines at the crown edge of particular tree species can only be explained by lateral flow processes within tree crowns. This study tests the hypothesis that lateral water translocation within the crown can be determined from simultaneous records of precipitation at defined measurement points below and above the canopy by taking single-tree characteristics such as species and crown width into account. Spatially explicit simultaneous measurements of gross precipitation (above-canopy reference) and throughfall were conducted repeatedly at 175 measurements points in a mixed European beech-Norway spruce stand for a total of 26 individual rain events. Subsequent analysis with a new regression approach resulted in an estimated average canopy storage capacity of 3.5 mm and 5.8 mm for beech (leaf-bearing period) and spruce stands, respectively. Values of calculated lateral flow showed considerable variability between individual measurement points. The highest discharge amounts were observed at positions below the inner beech crowns during the leaf-bearing period. For an exemplary rainfall event with a gross precipitation of 25 mm, the predicted discharge ranged from 5 mm underneath the inner beech crown to about zero near the crown edge. A comparison with the measured values indicated that the predicted amount of lateral flow, which could be translated into stemflow for single beech trees, was realistic. However, for the same rainfall event, lateral flow in

  17. Impacts of a water stress followed by an early frost event on beech (Fagus sylvatica L.) susceptibility to Scolytine ambrosia beetles - Research strategy and first results

    NASA Astrophysics Data System (ADS)

    La Spina, Sylvie; de Cannière, Charles; Molenberg, Jean-Marc; Vincke, Caroline; Deman, Déborah; Grégoire, Jean-Claude

    2010-05-01

    Climate change tends to induce more frequent abiotic and biotic extreme events, having large impacts on tree vitality. Weakened trees are then more susceptible to secondary insect outbreaks, as it happened in Belgium in the early 2000s: after an early frost event, secondary Scolytine ambrosia beetles attacks were observed on beech trees. In this study, we test if a combination of stress, i.e. a soil water deficit preceding an early frost, could render trees more attractive to beetles. An experimental study was set in autumn 2008. Two parcels of a beech forest were covered with plastic tents to induce a water stress by rain interception. The parcels were surrounded by 2-meters depth trenches to avoid water supply by streaming. Soil water content and different indicators of tree water use (sap flow, predawn leaf water potential, tree radial growth) were followed. In autumn 2010, artificial frost injuries will be inflicted to trees using dry ice. Trees attractivity for Scolytine insects, and the success of insect colonization will then be studied. The poster will focus on experiment setting and first results (impacts of soil water deficit on trees).

  18. Increased phytotoxic O3 dose accelerates autumn senescence in an O3-sensitive beech forest even under the present-level O3.

    PubMed

    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

    2016-01-01

    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. PMID:27601188

  19. Increased phytotoxic O3 dose accelerates autumn senescence in an O3-sensitive beech forest even under the present-level O3

    PubMed Central

    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

    2016-01-01

    Ground-level ozone (O3) concentrations are expected to increase over the 21st 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. PMID:27601188

  20. Wide variation in spatial genetic structure between natural populations of the European beech (Fagus sylvatica) and its implications for SGS comparability

    PubMed Central

    Jump, A S; Rico, L; Coll, M; Peñuelas, J

    2012-01-01

    Identification and quantification of spatial genetic structure (SGS) within populations remains a central element of understanding population structure at the local scale. Understanding such structure can inform on aspects of the species' biology, such as establishment patterns and gene dispersal distance, in addition to sampling design for genetic resource management and conservation. However, recent work has identified that variation in factors such as sampling methodology, population characteristics and marker system can all lead to significant variation in SGS estimates. Consequently, the extent to which estimates of SGS can be relied on to inform on the biology of a species or differentiate between experimental treatments is open to doubt. Following on from a recent report of unusually extensive SGS when assessed using amplified fragment length polymorphisms in the tree Fagus sylvatica, we explored whether this marker system led to similarly high estimates of SGS extent in other apparently similar populations of this species. In the three populations assessed, SGS extent was even stronger than this previously reported maximum, extending up to 360 m, an increase in up to 800% in comparison with the generally accepted maximum of 30–40 m based on the literature. Within this species, wide variation in SGS estimates exists, whether quantified as SGS intensity, extent or the Sp parameter. Consequently, we argue that greater standardization should be applied in sample design and SGS estimation and highlight five steps that can be taken to maximize the comparability between SGS estimates. PMID:22354112

  1. Effects of Elevated Atmospheric CO2 on Microbial Community Structure at the Plant-Soil Interface of Young Beech Trees (Fagus sylvatica L.) Grown at Two Sites with Contrasting Climatic Conditions.

    PubMed

    Gschwendtner, Silvia; Leberecht, Martin; Engel, Marion; Kublik, Susanne; Dannenmann, Michael; Polle, Andrea; Schloter, Michael

    2015-05-01

    Soil microbial community responses to elevated atmospheric CO2 concentrations (eCO2) occur mainly indirectly via CO2-induced plant growth stimulation leading to quantitative as well as qualitative changes in rhizodeposition and plant litter. In order to gain insight into short-term, site-specific effects of eCO2 on the microbial community structure at the plant-soil interface, young beech trees (Fagus sylvatica L.) from two opposing mountainous slopes with contrasting climatic conditions were incubated under ambient (360 ppm) CO2 concentrations in a greenhouse. One week before harvest, half of the trees were incubated for 2 days under eCO2 (1,100 ppm) conditions. Shifts in the microbial community structure in the adhering soil as well as in the root rhizosphere complex (RRC) were investigated via TRFLP and 454 pyrosequencing based on 16S ribosomal RNA (rRNA) genes. Multivariate analysis of the community profiles showed clear changes of microbial community structure between plants grown under ambient and elevated CO2 mainly in RRC. Both TRFLP and 454 pyrosequencing showed a significant decrease in the microbial diversity and evenness as a response of CO2 enrichment. While Alphaproteobacteria dominated by Rhizobiales decreased at eCO2, Betaproteobacteria, mainly Burkholderiales, remained unaffected. In contrast, Gammaproteobacteria and Deltaproteobacteria, predominated by Pseudomonadales and Myxococcales, respectively, increased at eCO2. Members of the order Actinomycetales increased, whereas within the phylum Acidobacteria subgroup Gp1 decreased, and the subgroups Gp4 and Gp6 increased under atmospheric CO2 enrichment. Moreover, Planctomycetes and Firmicutes, mainly members of Bacilli, increased under eCO2. Overall, the effect intensity of eCO2 on soil microbial communities was dependent on the distance to the roots. This effect was consistent for all trees under investigation; a site-specific effect of eCO2 in response to the origin of the trees was not observed

  2. Assessing the use of delta(13)C natural abundance in separation of root and microbial respiration in a Danish beech (Fagus sylvatica L.) forest.

    PubMed

    Formánek, Pavel; Ambus, Per

    2004-01-01

    Our understanding of forest biosphere-atmosphere interactions is fundamental for predicting forest ecosystem responses to climatic changes. Currently, however, our knowledge is incomplete partly due to inability to separate the major components of soil CO(2) effluxes, viz. root respiration, microbial decomposition of soil organic matter and microbial decomposition of litter material. In this study we examined whether the delta(13)C characteristics of solid organic matter and respired CO(2) from different soil-C components and root respiration in a Danish beech forest were useful to provide information on the root respiration contribution to total CO(2) effluxes. The delta(13)C isotopic analyses of CO(2) were performed using a FinniganMAT Delta(PLUS) isotope-ratio mass spectrometer coupled in continuous flow mode to a trace gas preparation-concentration unit (PreCon). Gas samples in 2-mL crimp seal vials were analysed in a fully automatic mode with an experimental standard error +/-0.11 per thousand. We observed that the CO(2) derived from root-free mineral soil horizons (A, B(W)) was more enriched in (13)C (delta(13)C range -21.6 to -21.2 per thousand ) compared with CO(2) derived from root-free humus layers (delta(13)C range -23.6 to -23.4 per thousand ). The CO(2) evolved from root respiration in isolated young beech plants revealed a value intermediate between those for the soil humus and mineral horizons, delta(13)C(root) = -22.2 per thousand, but was associated with great variability (SE +/- 1.0 per thousand ) due to plant-specific differences. delta(13)C of CO(2) from in situ below-ground respiration averaged -22.8 per thousand, intermediate between the values for the humus layer and root respiration, but variability was great (SE +/- 0.4 per thousand ) due to pronounced spatial patterns. Overall, we were unable to statistically separate the CO(2) of root respiration vs. soil organic matter decomposition based solely on delta(13)C signatures, yet the trend in

  3. The role of the organic layer for phosphorus nutrition of young beech trees (Fagus sylvatica L.) at two sites differing in soil Phosphorus availability

    NASA Astrophysics Data System (ADS)

    Hauenstein, Simon

    2016-04-01

    Simon Hauenstein1, Thomas Pütz2, and Yvonne Oelmann1, 1 Geoecology, Department of Geosciences, University of Tübingen, Tübingen, Germany 2 Agrosphere (IBG-3), Forschungszentrum Jülich, Jülich, Germany The accumulation of an organic layer in forests is linked to the ratio between litterfall rates and decomposition rates with decomposition rates being decelerated due to acidification and associated nutrient depletion with proceeding ecosystem development. Nevertheless, the nutrient pool in the organic layer might still represent an important source for Phosphorus (P) nutrition of forests on nutrient-poor soils. Our objective was to assess the importance of the organic layer to P nutrition of young beech trees at two sites differing in soil P availability. We established a mesocosm experiment including plants and soil from a Phosphorus depleted forest site on a Haplic Podzol in Lüss and a Phosphorus rich forest site on a Eutric Cambisol in Bad Brückenau either with or without the organic layer. After 1 year under outdoor conditions, we applied 33P to the pots. After 0h, 24h, 48h, 96h, 192h, 528h we destructively harvested the young beech trees (separated into leaves, branches, stems) and sampled the organic layer and mineral soil of the pots. In each soil horizon we measured concentrations of resin-extractable P, plant available P fractions and total P. We extracted the xylem sap of the whole 2-year-old trees by means of scholander pressure bomb. 33P activity was measured for every compartment in soil and plant. The applied 33P was recovered mainly in the organic layer in Lüss, whereas it was evenly distributed among organic and mineral horizons in pots of Bad Brückenau soil. Comparing pots with and without an organic layer, the specific 33P activity differed by 323% between pots with and without an organic layer present in the Lüss soil. For both sites, the presence of the organic layer increased 33P activity in xylem sap compared to the treatment without

  4. Seasonal time-course of gradients of photosynthetic capacity and mesophyll conductance to CO2 across a beech (Fagus sylvatica L.) canopy.

    PubMed

    Montpied, Pierre; Granier, André; Dreyer, Erwin

    2009-01-01

    Leaf photosynthesis is known to acclimate to the actual irradiance received by the different layers of a canopy. This acclimation is usually described in terms of changes in leaf structure, and in photosynthetic capacity. Photosynthetic capacity is likely to be affected by mesophyll conductance to CO(2) which has seldom been assessed in tree species, and whose plasticity in response to local irradiance is still poorly known. Structural [N and chlorophyll content, leaf mass to area ratio (LMA)] and functional leaf traits [maximum carboxylation rate (V(cmax)), maximum light-driven electron flux (J(max)), and mesophyll conductance (g(i))] were assessed by measuring leaf response curves of net CO(2) assimilation versus intercellular CO(2) partial pressure, along a vertical profile across a beech canopy, and by fitting a version of the Farquhar model including g(i). The measurements were repeated five times during a growth season to catch potential seasonal variation. Irradiance gradients resulted in large decreasing gradients of LMA, g(i), V(cmax), and J(max). Relative allocation of leaf N to the different photosynthetic processes was only slightly affected by local irradiance. Seasonal changes after leaf expansion and before induction of leaf senescence were only minor. Structural equation modelling confirmed that LMA was the main driving force for changes in photosynthetic traits, with only a minor contribution of leaf Nitrogen content. In conclusion, mesophyll conductance to CO(2) displays a large plasticity that scales with photosynthetic capacity across a tree canopy, and that it is only moderately (if at all) affected by seasonal changes in the absence of significant soil water depletion. PMID:19457983

  5. The effect of carbohydrate accumulation and nitrogen deficiency on feedback regulation of photosynthesis in beech (Fagus sylvatica) under elevated CO2 concentration

    NASA Astrophysics Data System (ADS)

    Klem, K.; Urban, O.; Holub, P.; Rajsnerova, P.

    2012-04-01

    One of the main manifestations of global change is an increase in atmospheric CO2 concentration. Elevated concentration of CO2 has stimulating effect on plant photosynthesis and consequently also on the productivity. Long-term studies, however, show that this effect is progressively reduced due to feedback regulation of photosynthesis. The main causes of this phenomenon are considered as two factors: i) increased biomass production consumes a larger amount of nitrogen from the soil and this leads to progressive nitrogen limitation of photosynthesis, particularly at the level of the enzyme Rubisco, ii) the sink capacity is genetically limited and elevated CO2 concentration leads to increased accumulation of carbohydtrates (mainly sucrose, which is the main transport form of assimilates) in leaves. Increased concentrations of carbohydrates leads to a feedback regulation of photosynthesis by both, long-term feedback regulation of synthesis of the enzyme Rubisco, and also due to reduced capacity to produce ATP in the chloroplasts. However, mechanisms for interactive effects of nitrogen and accumulation of non-structural carbohydrates are still not well understood. Using 3-year-old Fagus sylvatica seedlings we have explored the interactive effects of nitrogen nutrition and sink capacity manipulation (sucrose feeding) on the dynamics of accumulation of non-structural carbohydrates and changes in photosynthetic parameters under ambient (385 μmol (CO2) mol-1) and elevated (700 μmol(CO2) mol-1) CO2 concentration. Sink manipulation by sucrose feeding led to a continuous increase of non-structural carbohydrates in leaves, which was higher in nitrogen fertilized seedlings. The accumulation of non-structural carbohydrates was also slightly stimulated by elevated CO2 concentration. Exponential decay (p <0.01) was observed in CO2 assimilation rate and stomatal conductance when the content of non-structural carbohydrates increased. However, this relationship was modified by the

  6. An interactive effect of simultaneous death of dwarf bamboo, canopy gap, and predatory rodents on beech regeneration.

    PubMed

    Abe, M; Miguchi, H; Nakashizuka, T

    2001-04-01

    To clarify the interactive effect of the simultaneous death of dwarf bamboo (Sasa kurilensis), forest canopy gap formation, and seed predators on beech (Fagus crenata) regeneration, we analyzed beech demography from seed fall until the end of the first growing season of seedlings in an old-growth forest near Lake Towada, northern Japan. The simultaneous death of S. kurilensis took place in 1995. We established four types of sampling site differing in forest canopy conditions (closed or gap) and Sasa status (dead or alive). Beech seed survival and emergence ratio were both highest in gaps with dead Sasa (gap-dead), because rate of predation was lowest. Seedling survival during the first growing season was also highest in the gap-dead treatment, because of less predation and less damping off. As a result, even though density of seed fall was lowest in the gap-dead treatment, the living seedling density there was highest at the end of the first growing season. Predation, which caused the greatest mortality during the seed and seedling stages, was significantly lower at both sites in gaps and sites with dead Sasa. This was probably due to changes in the behavior of rodents in response to the structure of the forest canopy and undergrowth. Both the death of Sasa and canopy gap formation allowed seedlings to avoid damping off because of the high light availability. The indirect effect of the simultaneous death of Sasa and canopy gap formation in reducing predation contributed more to beech regeneration than their direct effect in increasing light for the seedlings. PMID:24577661

  7. 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✰

    PubMed Central

    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

  8. 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.

    PubMed

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

    2016-09-01

    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

  9. Quantification of mRNAs and housekeeping gene selection for quantitative real-time RT-PCR normalization in European beech (Fagus sylvatica L.) during abiotic and biotic stress.

    PubMed

    Olbrich, Maren; Gerstner, Elke; Welzl, Gerhard; Fleischmann, Frank; Osswald, Wolfgang; Bahnweg, Günther; Ernst, Dieter

    2008-01-01

    Analyses of different plant stressors are often based on gene expression studies. Quantitative real-time RT-PCR (qRT-PCR) is the most sensitive method for the detection of low abundance transcripts. However, a critical point to note is the selection of housekeeping genes as an internal control. Many so-called 'housekeeping genes' are often affected by different stress factors and may not be suitable for use as an internal reference. We tested six housekeeping genes of European beech by qRT-PCR using the Sybr Green PCR kit. Specific primers were designed for 18S rRNA, actin, glyceraldehyde-3-phosphate dehydrogenase (GAPDH1, GAPDH2), a-tubulin, and ubiquitin-like protein. Beech saplings were treated with increased concentrations of either ozone or CO2. In parallel, the expression of these genes was analyzed upon pathogen infection with Phytophthora citricola. To test the applicability of these genes as internal controls under realistic outdoor conditions, sun and shade leaves of 60-year-old trees were used for comparison. The regulation of all genes was tested using a linear mixed-effect model of the R-system. Results from independent experiments showed that the only gene not affected by any treatment was actin. The expression of the other housekeeping genes varied more or less with the degree of stress applied. These results highlight the importance of undergoing an individual selection of internal control genes for different experimental conditions. PMID:18811005

  10. Response of Selected Woody Species to Inoculation with Phytophthora citricola and P. cactorum from European Beech Using Multiple Inoculation Methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora citricola and P. cactorum are important cosmopolitan plant pathogens with wide host ranges. Both species have recently been identified as the cause of bleeding canker of European beech (Fagus sylvatica) in the northeastern United States, but whether isolates from European beech had the...

  11. VOC emissions from beech, birch, and oak

    NASA Astrophysics Data System (ADS)

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

    2003-04-01

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

  12. Prevalence, distribution and identification of Phytophthora species from bleeding canker on European beech

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While bleeding canker of European beech (Fagus sylvatica) has long been recognized as a problem, the cause in the northeastern United States has not been clear. To resolve this, we surveyed for disease prevalence, identified the pathogens involved, proved their pathogenicity, compared protocols for ...

  13. ESTIMATING ROOT RESPIRATION IN SPRUCE AND BEECH: DECREASES IN SOIL RESPIRATION FOLLOWING GIRDLING

    EPA Science Inventory

    A study was undertaken to follow seasonal fluxes of CO2 from soil and to estimate the contribution of autotrophic (root + mycorrhizal) to total soil respiration (SR) in a mixed stand of European beech (Fagus sylvatica) and Norway spruce (Picea abies) near Freising, Germany. Matu...

  14. SOIL CO2 EFFLUX FROM ISOTOPICALLY LABELED BEECH AND SPRUCE IN SOUTHERN GERMANY

    EPA Science Inventory

    • Carbon acquisition and transport to roots in forest trees is difficult to quantify and is affected by a number of factors, including micrometeorology and anthropogenic stresses. The canopies of mature European beech (Fagus sylvatica) and Norway spruce (Picea abies) were expose...

  15. DECLINE IN SOIL CO2 EFFLUX FOLLOWING TREE GIRTLING IN MATURE BEECH AND SPRUCE STANDS IN GERMANY

    EPA Science Inventory

    Studies were undertaken to estimate the contribution of autotrophic respiration to total soil CO2 efflux in stands of mature European beech (Fagus sylvatica) and Norway spruce (Picea abies) near Freising, Germany. Five mature trees of each species were girdled to eliminate carbo...

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

    PubMed Central

    Maynard, Lauren; Lemoine, Nathan P.; Shue, Jessica; Parker, John D.

    2014-01-01

    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. PMID:25024911

  17. Some important physical properties of laminated veneer lumber (Lvl) made from oriental beech and Lombardy poplar

    NASA Astrophysics Data System (ADS)

    Kılıç, Murat

    2012-09-01

    This study examined some physical characteristics of laminated veneer lumber (LVL) obtained in different compositions from cut veneers of Oriental beech (Fagus Orientalis Lipsky) and Lombardy poplar (Populus nigra) with thicknesses of 4 mm and 5 mm. Five each beech and poplar trees were felled with this objective. The PVAc (Kleiberit 303) and PU (Bizon Timber PU-Max Express) types of adhesive were used in lamination. The air-dry and oven dry densities, cell wall density and porosity, the value of volume density, shrinkage in a tangential and radial direction and volume swelling amounts were determined by preparing the specimens in accordance with the standards.

  18. Carbon flux to woody tissues in a beech/spruce forest during summer and in response to chronic O3 exposure

    EPA Science Inventory

    The present study compares the dynamics in carbon (C) allocation of adult deciduous beech (Fagus sylvatica) and evergreen spruce (Picea abies) during summer and in response to seven-year-long exposure with twice-ambient ozone (O3) concentrations (2 × O3). Focus was on the respira...

  19. The phylogeography of Fagus hayatae (Fagaceae): genetic isolation among populations.

    PubMed

    Ying, Ling-Xiao; Zhang, Ting-Ting; Chiu, Ching-An; Chen, Tze-Ying; Luo, Shu-Jin; Chen, Xiao-Yong; Shen, Ze-Hao

    2016-05-01

    The beech species Fagus hayatae is an important relict tree species in subtropical China, whose biogeographical patterns may reflect floral responses to climate change in this region during the Quaternary. Previous studies have revealed phylogeography for three of the four Fagus species in China, but study on F. hayatae, the most sparsely distributed of these species, is still lacking. Here, molecular methods based on eight simple sequence repeat (SSR) loci of nuclear DNA (nDNA) and three chloroplast DNA (cpDNA) sequences were applied for analyses of genetic diversity and structure in 375 samples from 14 F. hayatae populations across its whole range. Both nDNA and cpDNA indicated a high level of genetic diversity in this species. Significant fixation indexes and departures from the Hardy-Weinberg equilibrium, with a genetic differentiation parameter of R st of 0.233, were detected in nDNA SSR loci among populations, especially those on Taiwan Island, indicating strong geographic partitioning. The populations were classified into two clusters, without a prominent signal of isolation-by-distance. For the 15 haplotypes detected in the cpDNA sequence fragments, there was a high genetic differentiation parameter (G st = 0.712) among populations. A high G st of 0.829 was also detected outside but not within the Sichuan Basin. Consistent with other Fagus species in China, no recent population expansion was detected from tests of neutrality and mismatch distribution analysis. Overall, genetic isolation with limited gene flow was prominent for this species and significant phylogeographic structures existed across its range except for those inside the Sichuan Basin. Our study suggested long-term geographic isolation in F. hayatae with limited population admixture and the existence of multiple refugia in the mountainous regions of the Sichuan Basin and southeast China during the Quaternary. These results may provide useful information critical for the conservation of F

  20. Effect of flooding on C metabolism of flood-tolerant (Quercus robur) and non-tolerant (Fagus sylvatica) tree species.

    PubMed

    Ferner, Eleni; Rennenberg, Heinz; Kreuzwieser, Jürgen

    2012-02-01

    Flooding is assumed to cause an energy crisis in plants because-due to a lack of O(2)-mitochondrial respiration is replaced by alcoholic fermentation which yields considerably less energy equivalents. In the present study, the effect of flooding on the carbon metabolism of flooding-tolerant pedunculate oak (Quercus robur L.) and flooding-sensitive European beech (Fagus sylvatica L.) seedlings was characterized. Whereas soluble carbohydrate concentrations dropped in roots of F. sylvatica, they were constant in Q. robur during flooding. At the same time, root alcohol dehydrogenase activities were decreased in beech but not in oak, suggesting substrate limitation of alcoholic fermentation in beech roots. Surprisingly, leaf and phloem sap sugar concentrations increased in both species but to a much higher degree in beech. This finding suggests that the phloem unloading process in flooding-sensitive beech was strongly impaired. It is assumed that root-derived ethanol is transported to the leaves via the transpiration stream. This mechanism is considered an adaptation to flooding because it helps avoid the accumulation of toxic ethanol in the roots and supports the whole plant's carbon metabolism by channelling ethanol into the oxidative metabolism of the leaves. A labelling experiment demonstrated that in the leaves of flooded trees, ethanol metabolism does not differ between flooded beech and oak, indicating that processes in the roots are crucial for the trees' flooding tolerance. PMID:22367762

  1. Formation of cis-coniferin in cell-free extracts of Fagus grandifolia Ehrh bark

    SciTech Connect

    Yamamoto, Etsuo; Inciong, M.E.J.; Davin, L.B.; Lewis, N.G. )

    1990-09-01

    American beech (Fagus grandifolia Ehrh) bark exclusively accumulates cis-monolignols and their glucosidic conjugates; no evidence for the accumulation of trans-monolignols has been found. The glucosyltransferase from this source exhibits a very unusual substrate specificity for cis, and not trans, monolignols. This is further evidence that cis monolignols are involved in lignin formation in these plant tissues. Preliminary evidence for the existence of a novel trans-cis monolignol isomerase was obtained, in agreement with our contention that this isomerization is not photochemically mediated.

  2. Formation of cis-coniferin in cell-free extracts of Fagus grandifolia Ehrh bark

    NASA Technical Reports Server (NTRS)

    Yamamoto, E.; Inciong, E. J.; Davin, L. B.; Lewis, N. G.

    1990-01-01

    American beech (Fagus grandifolia Ehrh) bark exclusively accumulates cis-monolignols and their glucosidic conjugates; no evidence for the accumulation of trans-monolignols has been found. The glucosyltransferase from this source exhibits a very unusual substrate specificity for cis, and not trans, monolignols. This is further evidence that cis monolignols are involved in lignin formation in these plant tissues. Preliminary evidence for the existence of a novel trans-cis monolignol isomerase was obtained, in agreement with our contention that this isomerization is not photochemically mediated.

  3. Do variations in leaf phenology affect radial growth variations in Fagus sylvatica?

    NASA Astrophysics Data System (ADS)

    Čufar, Katarina; De Luis, Martin; Prislan, Peter; Gričar, Jožica; Črepinšek, Zalika; Merela, Maks; Kajfež-Bogataj, Lučka

    2015-08-01

    We used a dendrochronological and leaf phenology network of European beech ( Fagus sylvatica) in Slovenia, a transitional area between Mediterranean, Alpine and continental climatic regimes, for the period 1955-2007 to test whether year to year variations in leaf unfolding and canopy duration (i.e. time between leaf unfolding and colouring) influence radial growth (annual xylem production and tree ring widths) and if such influences are more pronounced at higher altitudes. We showed that variability in leaf phenology has no significant effect on variations in radial growth. The results are consistent in the entire region, irrespective of the climatic regime or altitude, although previous studies have shown that leaf phenology and tree ring variation depend on altitude. The lack of relationship between year to year variability in leaf phenology and radial growth may suggest that earlier leaf unfolding—as observed in a previous study—probably does not cause increased tree growth rates in beech in Slovenia.

  4. Upland beech trees significantly contribute to forest methane exchange

    NASA Astrophysics Data System (ADS)

    Machacova, Katerina; Maier, Martin; Svobodova, Katerina; Halaburt, Ellen; Haddad, Sally; Lang, Friederike; Urban, Otmar

    2016-04-01

    Methane (CH4) can be emitted not only from soil, but also from plants. Fluxes of CH4were predominantly investigated in riparian herbaceous plants, whereas studies on trees, particularly those lacking an aerenchyma, are rare. In soil produced CH4 can be taken up by roots, transported via intercellular spaces and the aerenchyma system, or transpiration stream to aboveground plant tissues and released to the atmosphere via lenticels or stomata. Although CH4 might be also produced by microorganisms living in plant tissues or photochemical processes in plants, these processes are relatively minor. It has been shown that seedlings of European beech (Fagus sylvatica) emit CH4 from its stems despite the lack of an aerenchyma. Our objectives were to determine the CH4 fluxes from mature beech trees and adjacent soil under natural field conditions, and to estimate the role of trees in the CH4exchange within the soil-tree-atmosphere continuum. Measurements were conducted in two mountain beech forests with different geographical and climatic conditions (White Carpathians, Czech Republic; Black Forest, Germany). CH4 fluxes at stems (profile) and root bases level were simultaneously measured together with soil-atmosphere fluxes using static chamber systems followed by chromatographic analysis or continuous laser detection of CH4 concentrations. Our study shows that mature beech trees have the ability to exchange CH4 with the atmosphere. The beech stems emitted CH4 into the atmosphere at the White Carpathians site in the range from 2.00 to 179 μg CH4 m‑2 stem area h‑1, while CH4 flux rates ranged between -1.34 to 1.73 μg CH4 m‑2 h‑1 at the Black Forest site. The root bases of beech trees from the White Carpathians released CH4 into the atmosphere (from 0.62 to 49.8 μg CH4 m‑2 root area h‑1), whereas a prevailing deposition was observed in the Black Forest (from -1.21 to 0.81 μg CH4 m‑2 h‑1). These fluxes seem to be affected by soil water content and its spatial

  5. The genome analysis of Candidatus Burkholderia crenata reveals that secondary metabolism may be a key function of the Ardisia crenata leaf nodule symbiosis.

    PubMed

    Carlier, Aurelien; Fehr, Linda; Pinto-Carbó, Marta; Schäberle, Till; Reher, Raphael; Dessein, Steven; König, Gabriele; Eberl, Leo

    2016-09-01

    A majority of Ardisia species harbour Burkholderia sp. bacteria within specialized leaf nodules. The bacteria are transmitted hereditarily and have not yet been cultured outside of their host. Because the plants cannot develop beyond the seedling stage without their symbionts, the symbiosis is considered obligatory. We sequenced for the first time the genome of Candidatus Burkholderia crenata (Ca. B. crenata), the leaf nodule symbiont of Ardisia crenata. The genome of Ca. B. crenata is the smallest Burkholderia genome to date. It contains a large amount of insertion sequences and pseudogenes and displays features consistent with reductive genome evolution. The genome does not encode functions commonly associated with plant symbioses such as nitrogen fixation and plant hormone metabolism. However, we identified unique genes with a predicted role in secondary metabolism in the genome of Ca. B. crenata. Specifically, we provide evidence that the bacterial symbionts are responsible for the synthesis of compound FR900359, a cyclic depsipeptide with biomedical properties previously isolated from leaves of A. crenata. PMID:26663534

  6. Growth of Fagus in transition zones of forest and soil on the western slope of Mt. Chokai, northern Japan

    NASA Astrophysics Data System (ADS)

    Kato, S.; Watanabe, M.

    2012-04-01

    A wide transition zone for forest structure is expected to distribute on the gentle slope of western side of Mt. Chokai ,Yamagata prefecture, northern Japan (N39° 05'57", E140°02'55"). The annual mean temperature and total precipitation at summit (2,059 m asl.) are 0.5° C and 3,285mm, respectively. The parent materials of the soils are weathered Andesite associated with non-tephric loess deposits transported from continental China. Representative sites were selected in forests of Quercus mongolica and Fagus crenata to examine characteristics of transition zones of vegetation and soil in the western slope of Mt. Chokai with concern on the growth of Fagus in transition zones. Surveys on vegetation profile and projection diagram of canopy for each site (10-10m plots) were carried out in 7 sites selected along altitudinal sequence on the western slope of Mt. Chokai; Ch1-7: 550-1,100m asl.. Growth rate of Fagus was estimated by the measurement of tree rings from increment core samples. Timber volume of Fagus at each point was calculated based on diameter of breast height; DBH as an indicator of tree biomass. Soil profiles were observed at the above 7 sites and soil samples were collected from each horizon. As for soil analyses, soil pH (H2O, KCl, NaF) values were measured by the glass electrode method in the suspension mixture of soil with a 2.5 times volume of H2O or 1N KCl and 50 times volume of 4% NaF. Pyrophosphate, acid oxalate and dithionite-citrate extractable Al (Alp, Alo, Ald), Fe (Feo, Fed) and Si (Sio, Sid) were measured by ICP-AES. The content of exchangeable Al (AlEX) was obtained by titration of extract with 1N KCl. Sclerotia formed by species of Cenococcum, ectomycorrhizal fungi, were collected for grains of diameter larger than 0.5mm from wet samples. Sclerotia content was obtained by weight (mg g-1 soil). Due to intensive base leaching under extremely high precipitation and the mineralogical properties, Ah and Ae horizons of all profiles had low soil

  7. Inhibition of Orobanche crenata seed germination and radicle growth by allelochemicals identified in cereals.

    PubMed

    Fernández-Aparicio, Mónica; Cimmino, Alessio; Evidente, Antonio; Rubiales, Diego

    2013-10-16

    Orobanche crenata is a parasitic weed that causes severe yield losses in important grain and forage legume crops. Cereals have been reported to inhibit O. crenata parasitism when grown intercropped with susceptible legumes, but the responsible metabolites have not been identified. A number of metabolites have been reported in cereals that have allelopathic properties against weeds, pests, and pathogens. We tested the effect of several allelochemicals identified in cereals on O. crenata seed germination and radicle development. We found that 2-benzoxazolinone, its derivative 6-chloroacetyl-2-benzoxazolinone, and scopoletin significantly inhibited O. crenata seed germination. Benzoxazolinones, l-tryptophan, and coumalic acid caused the stronger inhibition of radicle growth. Also, other metabolites reduced radicle length, this inhibition being dose-dependent. Only scopoletin caused cell necrotic-like darkening in the young radicles. Prospects for their application to parasitic weed management are discussed. PMID:24044614

  8. Priority effects during fungal community establishment in beech wood.

    PubMed

    Hiscox, Jennifer; Savoury, Melanie; Müller, Carsten T; Lindahl, Björn D; Rogers, Hilary J; Boddy, Lynne

    2015-10-01

    Assembly history of fungal communities has a crucial role in the decomposition of woody resources, and hence nutrient cycling and ecosystem function. However, it has not been clearly determined whether the fungal species that arrive first may, potentially, dictate the subsequent pathway of community development, that is, whether there is a priority effect at the species level. We used traditional culture-based techniques coupled with sequencing of amplified genetic markers to profile the fungal communities in beech (Fagus sylvatica) disks that had been pre-colonised separately with nine species from various stages of fungal succession. Clear differences in community composition were evident following pre-colonisation by different species with three distinct successor communities identified, indicating that individual species may have pivotal effects in driving assembly history. Priority effects may be linked to biochemical alteration of the resource and combative ability of the predecessor. PMID:25798754

  9. Priority effects during fungal community establishment in beech wood

    PubMed Central

    Hiscox, Jennifer; Savoury, Melanie; Müller, Carsten T; Lindahl, Björn D; Rogers, Hilary J; Boddy, Lynne

    2015-01-01

    Assembly history of fungal communities has a crucial role in the decomposition of woody resources, and hence nutrient cycling and ecosystem function. However, it has not been clearly determined whether the fungal species that arrive first may, potentially, dictate the subsequent pathway of community development, that is, whether there is a priority effect at the species level. We used traditional culture-based techniques coupled with sequencing of amplified genetic markers to profile the fungal communities in beech (Fagus sylvatica) disks that had been pre-colonised separately with nine species from various stages of fungal succession. Clear differences in community composition were evident following pre-colonisation by different species with three distinct successor communities identified, indicating that individual species may have pivotal effects in driving assembly history. Priority effects may be linked to biochemical alteration of the resource and combative ability of the predecessor. PMID:25798754

  10. Fast recovery of carbon fluxes in beech saplings after drought

    NASA Astrophysics Data System (ADS)

    Blessing, Carola; Barthel, Matti; Gentsch, Lydia; Buchmann, Nina

    2015-04-01

    Drought is known to down-regulate above and belowground gas-exchange and to slow down carbon transport from shoot to the soil/root system of beech (Fagus sylvatica L.). However, given more frequent drought spells in a future climate, the resilience of beech to drought will also depend on the speed and magnitude of recovery of above and belowground carbon fluxes. In a climate chamber study with beech saplings, we measured shoot and soil CO2 fluxes and their carbon isotope signature during drought and consecutive recovery using laser spectroscopy. We aimed to determine the speed of recovery from drought after re-watering and to assess the coupling between above and belowground gas-exchange and carbon isotope fluxes at natural abundance during drought and subsequent recovery. CO2 fluxes responded strongly to drought; photosynthesis was decreased by 34%, soil respiration (during light) by 41% and stomatal conductance by 65%. Despite this drastic decrease in gas-exchange, carbon fluxes recovered within few days after re-watering - faster for aboveground physiological variables (four days) compared to soil respiration (seven days) - pointing towards a resilient behaviour of beech saplings to drought. Moreover, the drought response in soil respiration was better explained by stomatal conductance (R2=0.8) rather than photosynthesis (R2=0.62). Consequently, stomatal conductance, and thus water-mediated processes, played a pivotal role driving the coupling of above and belowground CO2 fluxes. Further, drought caused photosynthetic isotope discrimination to decrease by 8o which in turn was reflected in a significant increase in δ13C of recent photoassimilates (1.5-2.5 obar) , and could be also traced to δ13C of soil respiration, which increased by 1-1.5 obar) . However, the coupling between the isotopic signatures of above and belowground carbon fluxes (R2=0.15) was less pronounced compared to the coupling of above and belowground gas-exchange (R2=0.8). In summary, our

  11. Soil organic matter dynamics under Beech and Hornbeam as affected by soil biological activity

    NASA Astrophysics Data System (ADS)

    Kooijman, A. M.; Cammeraat, L. H.

    2009-04-01

    Organic matter dynamics are highly affected both the soil fauna as well as the source of organic matter, having important consequences for the spatial heterogeneity of organic matter storage and conversion. We studied oldgrowth mixed deciduous forests in Central-Luxemburg on decalcified dolomitic marl, dominated by high-degradable hornbeam (Carpinus betulus L.) or low-degradable beech (Fagus sylvatica L.). Decomposition was measured both in the laboratory and in the field. Litter decomposition was higher for hornbeam than for beech under laboratory conditions, but especially in the field, which is mainly to be attributed to macro-fauna activity, specifically to earthworms (Lumbricus terrestris and Allolobophora species). We also investigated differences between beech and hornbeam with regard to litter input and habitat conditions. Total litter input was the same, but contribution of beech and hornbeam litter clearly differed between the two species. Also, mass of the ectorganic horizon and soil C:N ratio were significantly higher for beech, which was reflected in clear differences in the development of ectorganic profiles on top of the soil. Under beech a mull-moder was clearly present with a well developed fermentation and litter horizon, whereas under hornbeam all litter is incorporated into the soil, leaving the mineral soil surface bear in late summer (mull-type of horizon). In addition to litter quality, litter decomposition was affected by pH and soil moisture. Both pH and soil moisture were higher under hornbeam than under beech, which may reflect differences in soil development and litter quality effects over longer time scales. Under beech, dense layers of low-degradable litter may prevent erosion, and increase clay eluviation and leaching of base cations, leading to acid and dry conditions, which further decrease litter decay. Under hornbeam, the soil is not protected by a litter layer, and clay eluviation and acidification may be counteracted by erosion

  12. Analgesic properties of the aqueous and ethanol extracts of the leaves of Kalanchoe crenata (Crassulaceae).

    PubMed

    Nguelefack, T B; Fotio, A L; Watcho, P; Wansi, S L; Dimo, T; Kamanyi, A

    2004-05-01

    The aqueous and ethanol extracts of the dry leaves of Kalanchoe crenata (300 and 600 mg/kg) were evaluated for their analgesic properties on the pain induced by acetic acid, formalin and heat in mice and by pressure on rats. The ethanol extract of K. crenata at a dose of 600 mg/kg produced an inhibition of 61.13% on pain induced by acetic acid and 50.13% for that induced by formalin. An inhibition of 67.18% was observed on pain induced by heat 45 min after the administration of the extract. The aqueous extract administered at a dose of 600 mg/kg produced a maximum effect of 25% on pain induced by pressure. These activities were similar to those produced by a paracetamol-codeine association, while indomethacin exhibited a protective effect only against the writhing test. Our results suggest that the leaves of K. crenata could be a source of analgesic compounds. PMID:15173998

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

    NASA Astrophysics Data System (ADS)

    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

  14. Living on the Edge: Contrasted Wood-Formation Dynamics in Fagus sylvatica and Pinus sylvestris under Mediterranean Conditions

    PubMed Central

    Martinez del Castillo, Edurne; Longares, Luis A.; Gričar, Jožica; Prislan, Peter; Gil-Pelegrín, Eustaquio; Čufar, Katarina; de Luis, Martin

    2016-01-01

    Wood formation in European beech (Fagus sylvatica L.) and Scots pine (Pinus sylvestris L.) was intra-annually monitored to examine plastic responses of the xylem phenology according to altitude in one of the southernmost areas of their distribution range, i.e., in the Moncayo Natural Park, Spain. The monitoring was done from 2011 to 2013 at 1180 and 1580 m a.s.l., corresponding to the lower and upper limits of European beech forest in this region. Microcores containing phloem, cambium and xylem were collected biweekly from twenty-four trees from the beginning of March to the end of November to assess the different phases of wood formation. The samples were prepared for light microscopy to observe the following phenological phases: onset and end of cell production, onset and end of secondary wall formation in xylem cells and onset of cell maturation. The temporal dynamics of wood formation widely differed among years, altitudes and tree species. For Fagus sylvatica, the onset of cambial activity varied between the first week of May and the third week of June. Cambial activity then slowed down and stopped in summer, resulting in a length of growing season of 48–75 days. In contrast, the growing season for P. sylvestris started earlier and cambium remained active in autumn, leading to a period of activity varying from 139-170 days. The intra-annual wood-formation pattern is site and species-specific. Comparison with other studies shows a clear latitudinal trend in the duration of wood formation, positive for Fagus sylvatica and negative for P. sylvestris. PMID:27047534

  15. Seasonal variation in N uptake strategies in the understorey of a beech-dominated N-limited forest ecosystem depends on N source and species.

    PubMed

    Li, Xiuyuan; Rennenberg, Heinz; Simon, Judy

    2016-05-01

    In forest ecosystems, species use different strategies to increase their competitive ability for nitrogen (N) acquisition. The acquisition of N by trees is regulated by tree internal and environmental factors including mycorrhizae. In this study, we investigated the N uptake strategies of three co-occurring tree species [European beech (Fagus sylvatica L.), sycamore maple (Acer pseudoplatanus L.) and Norway maple (Acer platanoides L.)] in the understorey of a beech-dominated, N-limited forest on calcareous soil over two consecutive seasons. For this purpose, we studied (15)N uptake capacity as well as the allocation to N pools in the fine roots. Our results show that European beech had a higher capacity for both inorganic and organic N acquisition throughout the whole growing season compared with sycamore maple and Norway maple. The higher capacity of N acquisition in beech indicates a better adaption of beech to the understorey conditions of beech forests compared with the seedlings of other tree competitors under N-limited conditions. Despite these differences, all three species preferred organic over inorganic N sources throughout the growing season and showed similar seasonal patterns of N acquisition with an increased N uptake capacity in summer. However, this pattern varied with N source and year indicating that other environmental factors not assessed in this study further influenced N acquisition by the seedlings of the three tree species. PMID:26786538

  16. Finders keepers, losers weepers - drought as a modifier of competition between European beech and Norway spruce -

    NASA Astrophysics Data System (ADS)

    Goisser, Michael; Blanck, Christian; Geppert, Uwe; Häberle, Karl-Heinz; Matyssek, Rainer; Grams, Thorsten E. E.

    2016-04-01

    Mixed stands of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.) frequently reflect over-yielding, when compared to respective monospecific stands. Over-yielding is attributed to enhanced resource uptake efficiency through niche complementarity alleviating species competition. Under climate change, however, with severe and frequent summer drought, water limitation may become crucial in modifying the competitive interaction between neighboring beech and spruce trees. In view of the demands by silvicultural practice, basic knowledge from experimental field work about competitive versus facilitative interaction in maturing mixed beech-spruce forests is scarce. To this end, we investigate species-specific drought response including underlying mechanisms of species interaction in a maturing group-wise mixed beech-spruce forest, amongst 60 and 53 adult trees of beech and spruce, respectively (spruce 65 ± 2, beech 85 ± 4 years old). Severe and repeated experimental drought is being induced over several years through a stand-scale approach of rain throughfall exclusion (Kranzberg Forest Roof Experiment, KROOF). The experimental design comprises 6 roofed (E, automated, closing only during rain) and 6 control (C) plots with a total area of almost 1800 square meters. In 2015 minimum predawn potentials of -2.16 MPa and -2.26 MPa were reached in E for beech and spruce respectively. At the leaf level, spruce displayed high drought susceptibility reflected by a distinct decrease in both stomatal conductance and net CO2 uptake rate by more than 80% each, suggesting isohydric response. Beech rather displayed anisohydry indicated by less pronounced yet significant reduction of stomatal conductance and net CO2 uptake rate by more than 55% and 45%, respectively. Under the C regime, a negative species interaction effect on stomatal conductance was found in beech, contrasting with a positive effect in spruce. However, drought reversed the effect of

  17. Immunolocalization of FsPK1 correlates this abscisic acid-induced protein kinase with germination arrest in Fagus sylvatica L. seeds.

    PubMed

    Reyes, David; Rodríguez, Dolores; Lorenzo, Oscar; Nicolás, Gregorio; Cañas, Rafael; Cantón, Francisco R; Canovas, Francisco M; Nicolás, Carlos

    2006-01-01

    An enzymatically active recombinant protein kinase, previously isolated and characterized in Fagus sylvatica L. dormant seeds (FsPK1), was used to obtain a specific polyclonal antibody against this protein. Immunoblotting and immunohistochemical analysis of FsPK1 protein in beech seeds showed a strong immunostaining in the nucleus of the cells located in the vascular tissue of the embryonic axis corresponding to the future apical meristem of the root. This protein kinase was found to accumulate in the seeds only when embryo growth was arrested by application of ABA, while the protein amount decreased during stratification, previously proved to alleviate dormancy, and no protein was detected at all when seed germination was induced by addition of GA(3). These results indicate that FsPK1 may be involved in the control of the embryo growth mediated by ABA and GAs during the transition from dormancy to germination in Fagus sylvatica seeds. PMID:16473890

  18. Identification of Starling Circovirus in an Estuarine Mollusc (Amphibola crenata) in New Zealand Using Metagenomic Approaches

    PubMed Central

    Dayaram, Anisha; Goldstien, Sharyn; Zawar-Reza, Peyman; Gomez, Christopher; Harding, Jon S.

    2013-01-01

    Two complete genomes of starling circovirus (StCV) were recovered from Amphibola crenata, an estuarine New Zealand mollusc. This is the first report of StCV outside Europe. The viral genomes were recovered from rolling circle-amplified enriched circular DNA followed by back-to-back primers and specific primer PCR amplification. PMID:23723397

  19. Conversion of Mountain Beech Coppices into High Forest: An Example for Ecological Intensification

    NASA Astrophysics Data System (ADS)

    Mattioli, Walter; Ferrari, Barbara; Giuliarelli, Diego; Mancini, Leone Davide; Portoghesi, Luigi; Corona, Piermaria

    2015-11-01

    Converting beech coppices into high forest stands has been promoted in the last decades as a management goal to attenuate the negative effects that frequent clearcutting may have on soil, landscape, and biodiversity conservation. The silvicultural tool usually adopted is the gradual thinning of shoots during the long span of time required to complete the conversion, that also allows the owner to keep harvesting some wood. This research reports and discusses, in the light of the ecological intensification approach, the results achieved from an experimental test started more than 25 years ago in a 42-year-old beech ( Fagus sylvatica L.) coppice with standards in central Italy. The effects of various thinning intensities (three treatments plus a control) on the stand growth and structure are assessed by successive forest inventories. Analyses are integrated by spatial indices to assess stem density and canopy cover. Converting beech coppices into high forest through gradual thinning of shoots proves to be an effective step down the road to silvicultural systems characterized by continuous forest cover, as a tool of ecological intensification suitable to guarantee both public and private interests. Thinning has led to stands with fewer but larger stems, thus accelerating the long conversion process while maintaining both wood harvesting capability and environmental services.

  20. Comparative phylogeography of two sympatric beeches in subtropical China: Species-specific geographic mosaic of lineages.

    PubMed

    Zhang, Zhi-Yong; Wu, Rong; Wang, Qun; Zhang, Zhi-Rong; López-Pujol, Jordi; Fan, Deng-Mei; Li, De-Zhu

    2013-11-01

    In subtropical China, large-scale phylogeographic comparisons among multiple sympatric plants with similar ecological preferences are scarce, making generalizations about common response to historical events necessarily tentative. A phylogeographic comparison of two sympatric Chinese beeches (Fagus lucida and F. longipetiolata, 21 and 28 populations, respectively) was conducted to test whether they have responded to historical events in a concerted fashion and to determine whether their phylogeographic structure is exclusively due to Quaternary events or it is also associated with pre-Quaternary events. Twenty-three haplotypes were recovered for F. lucida and F. longipetiolata (14 each one and five shared). Both species exhibited a species-specific mosaic distribution of haplotypes, with many of them being range-restricted and even private to populations. The two beeches had comparable total haplotype diversity but F. lucida had much higher within-population diversity than F. longipetiolata. Molecular dating showed that the time to most recent common ancestor of all haplotypes was 6.36 Ma, with most haplotypes differentiating during the Quaternary. [Correction added on 14 October 2013, after first online publication: the timeunit has been corrected to '6.36'.] Our results support a late Miocene origin and southwards colonization of Chinese beeches when the aridity in Central Asia intensified and the monsoon climate began to dominate the East Asia. During the Quaternary, long-term isolation in subtropical mountains of China coupled with limited gene flow would have lead to the current species-specific mosaic distribution of lineages. PMID:24340187

  1. Effects of rhizopheric nitric oxide (NO) on N uptake in Fagus sylvatica seedlings depend on soil CO2 concentration, soil N availability and N source.

    PubMed

    Dong, Fang; Simon, Judy; Rienks, Michael; Lindermayr, Christian; Rennenberg, Heinz

    2015-08-01

    Rhizospheric nitric oxide (NO) and carbon dioxide (CO2) are signalling compounds known to affect physiological processes in plants. Their joint influence on tree nitrogen (N) nutrition, however, is still unknown. Therefore, this study investigated, for the first time, the combined effect of rhizospheric NO and CO2 levels on N uptake and N pools in European beech (Fagus sylvatica L.) seedlings depending on N availability. For this purpose, roots of seedlings were exposed to one of the nine combinations (i.e., low, ambient, high NO plus CO2 concentration) at either low or high N availability. Our results indicate a significant effect of rhizospheric NO and/or CO2 concentration on organic and inorganic N uptake. However, this effect depends strongly on NO and CO2 concentration, N availability and N source. Similarly, allocation of N to different N pools in the fine roots of beech seedlings also shifted with varying rhizospheric gas concentrations and N availability. PMID:26093371

  2. Measuring and modelling plant area index in beech stands.

    PubMed

    Holst, T; Hauser, S; Kirchgässner, A; Matzarakis, A; Mayer, H; Schindler, D

    2004-05-01

    For some beech ( Fagus sylvatica L.) stands with different stand densities the plant area index (PAI) was measured by means of a Licor LAI-2000 plant canopy analyser. The stands are located on the slopes of a valley in south-west Germany and had been treated by different types of silvicultural management (heavy shelterwood felling, light shelterwood felling, control plot). The analyser was used (a) to investigate the light conditions on plots of the same thinning regime, (b) to quantify the differences between the different treatments and (c) to obtain absolute values of PAI for interdisciplinary research. PAI was measured at three different phenological stages (leafless, leaf-unfolding and fully leafed season in 2000) and was found to be about 5.2 for the fully developed canopy on the control plots, 3.2 on the light fellings and about 2.0 for the heavy fellings. In the leafless period PAI was between 1.1 (control) and 0.4 (heavy felling). Measurements made in summer 2000 and summer 2002 were compared, and showed an increase of PAI, especially on the thinned plots. Measurements of photosynthetically active radiation (PAR) above and below the canopy in combination with measured PAI were used to apply Beer's Law of radiation extinction to calculate the extinction coefficient k for different sky conditions and for the different growing seasons on the control plots. The extinction coefficient k for the beech stands was found to be between 0.99 and 1.39 in the leafless period, 0.62 to 0.91 during leaf unfolding and between 0.68 and 0.83 in the fully leafed period. Using PAR measurements and the k values obtained, the annual cycle of PAI was modelled inverting Beer's Law. PMID:14750004

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

    PubMed

    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. PMID:19344334

  4. Carbon and nitrogen fluxes between beech and their ectomycorrhizal assemblage.

    PubMed

    Valtanen, Kerttu; Eissfeller, Verena; Beyer, Friderike; Hertel, Dietrich; Scheu, Stefan; Polle, Andrea

    2014-11-01

    To determine the exchange of nitrogen and carbon between ectomycorrhiza and host plant, young beech (Fagus sylvatica) trees from natural regeneration in intact soil cores were labelled for one growing season in a greenhouse with (13)CO2 and (15)NO3 (15)NH4. The specific enrichments of (15)N and (13)C were higher in ectomycorrhizas (EMs) than in any other tissue. The enrichments of (13)C and (15)N were also higher in the fine-root segments directly connected with the EM (mainly second-order roots) than that in bulk fine or coarse roots. A strict, positive correlation was found between the specific (15)N enrichment in EM and the attached second-order roots. This finding indicates that strong N accumulators provide more N to their host than low N accumulators. A significant correlation was also found for the specific (13)C enrichment in EM and the attached second-order roots. However, the specific enrichments for (15)N and (13)C in EM were unrelated showing that under long-term conditions, C and N exchange between host and EMs are uncoupled. These findings suggest that EM-mediated N flux to the plant is not the main control on carbon flux to the fungus, probably because EMs provide many different services to their hosts in addition to N provision in their natural assemblages. PMID:24756632

  5. Thermopower of beech wood biocarbon

    NASA Astrophysics Data System (ADS)

    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 < 1000°C for all the measurement temperatures. This finding fits to the published data obtained for other physical parameters, including the electrical conductivity of these biocarbons, which suggests that for T carb ˜ 1000°C they undergo a phase transition of the insulator-(at T carb < 1000°C)-metal-(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.

  6. Species relationships and divergence times in beeches: new insights from the inclusion of 53 young and old fossils in a birth-death clock model.

    PubMed

    Renner, S S; Grimm, Guido W; Kapli, Paschalia; Denk, Thomas

    2016-07-19

    The fossilized birth-death (FBD) model can make use of information contained in multiple fossils representing the same clade, and we here apply this model to infer divergence times in beeches (genus Fagus), using 53 fossils and nuclear sequences for all nine species. We also apply FBD dating to the fern clade Osmundaceae, with about 12 living species and 36 fossils. Fagus nuclear sequences cannot be aligned with those of other Fagaceae, and we therefore use Bayes factors to choose among alternative root positions. The crown group of Fagus is dated to 53 (62-43) Ma; divergence of the sole American species to 44 (51-39) Ma and divergence between Central European F. sylvatica and Eastern Mediterranean F. orientalis to 8.7 (20-1.8) Ma, unexpectedly old. The FBD model can accommodate fossils as sampled ancestors or as extinct or unobserved lineages; however, this makes its raw output, which shows all fossils on short or long branches, problematic to interpret. We use hand-drawn depictions and a bipartition network to illustrate the uncertain placements of fossils. Inferred speciation and extinction rates imply approximately 5× higher evolutionary turnover in Fagus than in Osmundaceae, fitting a hypothesized low turnover in plants adapted to low-nutrient conditions.This article is part of the themed issue 'Dating species divergences using rocks and clocks'. PMID:27325832

  7. Advantages of masting in European beech: timing of granivore satiation and benefits of seed caching support the predator dispersal hypothesis.

    PubMed

    Zwolak, Rafał; Bogdziewicz, Michał; Wróbel, Aleksandra; Crone, Elizabeth E

    2016-03-01

    The predator satiation and predator dispersal hypotheses provide alternative explanations for masting. Both assume satiation of seed-eating vertebrates. They differ in whether satiation occurs before or after seed removal and caching by granivores (predator satiation and predator dispersal, respectively). This difference is largely unrecognized, but it is demographically important because cached seeds are dispersed and often have a microsite advantage over nondispersed seeds. We conducted rodent exclosure experiments in two mast and two nonmast years to test predictions of the predator dispersal hypothesis in our study system of yellow-necked mice (Apodemus flavicollis) and European beech (Fagus sylvatica). Specifically, we tested whether the fraction of seeds removed from the forest floor is similar during mast and nonmast years (i.e., lack of satiation before seed caching), whether masting decreases the removal of cached seeds (i.e., satiation after seed storage), and whether seed caching increases the probability of seedling emergence. We found that masting did not result in satiation at the seed removal stage. However, masting decreased the removal of cached seeds, and seed caching dramatically increased the probability of seedling emergence relative to noncached seeds. European beech thus benefits from masting through the satiation of scatterhoarders that occurs only after seeds are removed and cached. Although these findings do not exclude other evolutionary advantages of beech masting, they indicate that fitness benefits of masting extend beyond the most commonly considered advantages of predator satiation and increased pollination efficiency. PMID:26612728

  8. Aphid infestation affecting the biogeochemistry of European beech saplings

    NASA Astrophysics Data System (ADS)

    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 < PN < 500 μm) in TF solution by 42% for K+, 59% for Mn2+ and 13% for PN relative to the control. In contrast, fluxes of NH4-N and SO4-S diminished during peaking aphid abundance by 26 and 16%, respectively. Differences in canopy-derived dissolved nitrogen and carbon compounds, sulfur (S), Ca2+, Mg2+, Na+ were < 10%. The effect of 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. Fungal community in sclerotia of Japanese Beech forest soils in north eastern Japan

    NASA Astrophysics Data System (ADS)

    Fathia Amasya, Anzilni; Narisawa, Kazuhiko; Watanabe, Makiko

    2014-05-01

    Sclerotia are resting structures of ectomycorrhizal fungi and appear as a response to unfavorable environmental conditions such as desiccation. They are hard, black, comparatively smooth and mostly spherical. Sclerotia are formed in rhizosphere and the 14C ages of sclerotia from A horizons of volcanic ash soils may range from modern until ca. 100~1,200 yr B.P. Most sclerotia-forming fungal species are known to be host-specific plant pathogens and therefore their abundance may indicate the presence of their host plants. The purpose of this study was to investigate fungal communities in sclerotia with an interest in describing the existing or may have previously existed host plant community. To investigate fungal community inside of sclerotia by 16S rDNA gene clone library, several hundred of sclerotia (ca. 1g) were collected from Fagus crenata forest soil in north eastern Japan. The rDNA ITS regions were then amplified by the PCR using primer pair ITS-1F/ITS-4. Aliquots of the amplified DNA were digested with restriction endonucleases AluI, Hae III, and HhaI to obtain ITS-RFLPs. To obtain the fungal community profiles a quenching fluorescence primer was used for real-time quantitative PCR (qPCR) assay to monitor the PCR amplification and then used for T-RFLP. The predominant group determined by clone library analysis from the sclerotia was Ascomycota: Arthrinium arundinis, which has been reported to be one of the soil fungal species responsible for bamboo degradation and a pathogen for many species belonging to Poaceae family.

  10. Temperature and water stress during conditioning and incubation phase affecting Orobanche crenata seed germination and radicle growth

    PubMed Central

    Moral, Juan; Lozano-Baena, María Dolores; Rubiales, Diego

    2015-01-01

    Orobanche crenata is a holoparasitic plant that is potentially devastating to crop yield of legume species. Soil temperature and humidity are known to affect seed germination, however, the extent of their influence on germination and radicle growth of those of O. crenata is largely unknown. In this work, we studied the effects of temperature, water potential (Ψt) and the type of water stress (matric or osmotic) on O. crenata seeds during conditioning and incubation periods. We found that seeds germinated between 5 and 30°C during both periods, with a maximum around 20°C. Germination increased with increasing Ψt from −1.2 to 0 MPa during conditioning and incubation periods. Likewise, seed germination increased logarithmically with length of conditioning period until 40 days. The impact of the type of water stress on seed germination was similar, although the radicle growth of seeds under osmotic stress was lower than under matric stress, what could explain the lowest infestation of Orobanche sp. in regions characterized by saline soil. The data in this study will be useful to forecast infection of host roots by O. crenata. PMID:26089829

  11. Temperature and water stress during conditioning and incubation phase affecting Orobanche crenata seed germination and radicle growth.

    PubMed

    Moral, Juan; Lozano-Baena, María Dolores; Rubiales, Diego

    2015-01-01

    Orobanche crenata is a holoparasitic plant that is potentially devastating to crop yield of legume species. Soil temperature and humidity are known to affect seed germination, however, the extent of their influence on germination and radicle growth of those of O. crenata is largely unknown. In this work, we studied the effects of temperature, water potential (Ψt) and the type of water stress (matric or osmotic) on O. crenata seeds during conditioning and incubation periods. We found that seeds germinated between 5 and 30°C during both periods, with a maximum around 20°C. Germination increased with increasing Ψt from -1.2 to 0 MPa during conditioning and incubation periods. Likewise, seed germination increased logarithmically with length of conditioning period until 40 days. The impact of the type of water stress on seed germination was similar, although the radicle growth of seeds under osmotic stress was lower than under matric stress, what could explain the lowest infestation of Orobanche sp. in regions characterized by saline soil. The data in this study will be useful to forecast infection of host roots by O. crenata. PMID:26089829

  12. Fast acclimation of freezing resistance suggests no influence of winter minimum temperature on the range limit of European beech.

    PubMed

    Lenz, Armando; Hoch, Günter; Vitasse, Yann

    2016-04-01

    Low temperature extremes drive species distribution at a global scale. Here, we assessed the acclimation potential of freezing resistance in European beech (Fagus sylvaticaL.) during winter. We specifically asked (i) how do beech populations growing in contrasting climates differ in their maximum freezing resistance, (ii) do differences result from genetic differentiation or phenotypic plasticity to preceding temperatures and (iii) is beech at risk of freezing damage in winter across its distribution range. We investigated the genetic and environmental components of freezing resistance in buds of adult beech trees from three different populations along a natural large temperature gradient in north-western Switzerland, including the site holding the cold temperature record in Switzerland. Freezing resistance of leaf primordia in buds varied significantly among populations, with LT50values (lethal temperature for 50% of samples) ranging from -25 to -40 °C, correlating with midwinter temperatures of the site of origin. Cambial meristems and the pith of shoots showed high freezing resistance in all three populations, with only a trend to lower freezing resistance at the warmer site. After hardening samples at -6 °C for 5 days, freezing resistance of leaf primordia increased in all provenances by up to 4.5 K. After additional hardening at -15 °C for 3 days, all leaf primordia were freezing resistant to -40 °C. We demonstrate that freezing resistance ofF. sylvaticahas a high ability to acclimate to temperature changes in winter, whereas the genetic differentiation of freezing resistance among populations seems negligible over this small geographic scale but large climatic gradient. In contrast to the assumption made in most of the species distribution models, we suggest that absolute minimum temperature in winter is unlikely to shape the cold range limit of beech. We conclude that the rapid acclimation of freezing resistance to winter temperatures allows

  13. Wood structural differences between northern and southern beech provenances growing at a moderate site.

    PubMed

    Eilmann, B; Sterck, F; Wegner, L; de Vries, S M G; von Arx, G; Mohren, G M J; den Ouden, J; Sass-Klaassen, U

    2014-08-01

    Planting provenances originating from southern to northern locations has been discussed as a strategy to speed up species migration and mitigate negative effects of climate change on forest stability and productivity. Especially for drought-susceptible species such as European beech (Fagus sylvatica L.), the introduction of drought-tolerant provenances from the south could be an option. Yet, beech has been found to respond plastically to environmental conditions, suggesting that the climate on the plantation site might be more important for tree growth than the genetic predisposition of potentially drought-adapted provenances. In this study, we compared the radial growth, wood-anatomical traits and leaf phenology of four beech provenances originating from southern (Bulgaria, France) and northern locations (Sweden, the Netherlands) and planted in a provenance trial in the Netherlands. The distribution of precipitation largely differs between the sites of origin. The northern provenances experience a maximum and the southern provenances experience a minimum of rainfall in summer. We compared tree productivity and the anatomy of the water-conducting system for the period from 2000 to 2010, including the drought year 2003. In addition, tree mortality and the timing of leaf unfolding in spring were analysed for the years 2001, 2007 and 2012. Comparison of these traits in the four beech provenances indicates the influence of genetic predisposition and local environmental factors on the performance of these provenances under moderate site conditions. Variation in radial growth was controlled by environment, although the growth level slightly differed due to genetic background. The Bulgarian provenance had an efficient water-conducting system which was moreover unaffected by the drought in 2003, pointing to a high ability of this provenance to cope well with dry conditions. In addition, the Bulgarian provenance showed up as most productive in terms of height and radial

  14. Measuring and modelling precipitation components in an Oriental beech stand of the Hyrcanian region, Iran

    NASA Astrophysics Data System (ADS)

    Rahmani, Ramin; Sadoddin, Amir; Ghorbani, Somayeh

    2011-07-01

    SummaryInterception loss from the canopy is a major pathway for the loss of water from forest ecosystems. This study was conducted in an Oriental beech stand, neighboring Gorgan, representing typical forest characteristics of the Hyrcanian region. The Hyrcanian region is situated to the south of the Caspian Sea and covers approximately 1.8 million ha of the northern foothills of the Alborz Mountains in northern Iran. This region is characterised by temperate deciduous forests with Oriental beech stands, formed mainly of Fagus orientalis. Because these beech stands occupy 80% of the Hyrcanian region, rainfall interception via the tree canopy is an important pathway for water loss in this region. The main objectives of this study were to determine and model the precipitation components including stemflow, throughfall, net precipitation, and interception loss using gross precipitation and to understand how the diameter classes influence precipitation partitioning by comparing precipitation components across the tree diameter classes. A total of 31 beech trees with the following classes of diameter were randomly chosen: 11 trees of 30-60 cm (young), 10 trees of 60-100 cm (middle-aged), and 10 trees of 100-130 cm (old) of Diameter at Breast Height (DBH). Field measurements of gross precipitation, stemflow, and throughfall were made for 33 rainfall events over a period of 12 months from November 2005. Then, based on these measurements, net precipitation and interception loss were calculated. The value of gross precipitation was approximately 827 mm. Interception loss estimated to be about 53%, 57%, and 60% of gross precipitation corresponding to the tree diameter classes of 30-60, 60-100, and 100-130 cm, respectively. ANOVA results show that the values of the mean of precipitation components were significantly different across the diameter classes. There was an indirect relationship between tree diameter and the volumes of stemflow, throughfall, and net precipitation

  15. Comparison of the carbon stock in forest soil of sessile oak and beech forests

    NASA Astrophysics Data System (ADS)

    Horváth, Adrienn; Bene, Zsolt; Bidló, András

    2016-04-01

    Forest ecosystems are the most important carbon sinks. The forest soils play an important role in the global carbon cycle, because the global climate change or the increase of atmospheric CO2 level. We do not have enough data about the carbon stock of soils and its change due to human activities, which have similar value to carbon content of biomass. In our investigation we measured the carbon stock of soil in 10 stands of Quercus petraea and Fagus sylvatica. We took a 1.1 m soil column with soil borer and divided to 11 samples each column. The course organic and root residues were moved. After evaluation, we compared our results with other studies and the carbon stock of forests to each other. Naturally, the amount of SOC was the highest in the topsoil layers. However, we found significant difference between forest stands which stayed on the same homogenous bedrock, but very close to each other (e.g. distance was 1 or 2 km). We detected that different forest utilizations and tree species have an effect on the forest carbon as the litter as well (amount, composition). In summary, we found larger amount (99.1 C t/ha on average) of SOC in soil of stands, where sessile oak were the main stand-forming tree species. The amount of carbon was the least in turkey oak-sessile oak stands (85.4 C t/ha on average). We found the highest SOC (118.3 C t/ha) in the most mixed stand (silver lime-beech-red oak). In the future, it will be very important: How does climate change affect the spread of tree species or on carbon storage? Beech is more sensitive, but even sessile oak. These species are expected to replace with turkey oak, which is less sensitive to drought. Thus, it is possible in the future that we can expect to decrease of forest soil carbon stock capacity, which was confirmed by our experiment. Keywords: carbon sequestration, mitigation, Fagus sylvatica, Quercus petraea, litter Acknowledgements: Research is supported by the "Agroclimate.2" (VKSZ_12-1-2013-0034) EU

  16. In vitro antimicrobial activity of crude extracts from plants Bryophyllum pinnatum and Kalanchoe crenata.

    PubMed

    Akinsulire, Odunayo R; Aibinu, Ibukun E; Adenipekun, Tayo; Adelowotan, Toyin; Odugbemi, Tolu

    2007-01-01

    Extracts from the leaves of Bryophyllum pinnatum and Kalanchoe crenata were screened for their antimicrobial activities. Solvents used included water, methanol, and local solvents such as palmwine, local gin (Seaman's Schnapps 40% alcoholic drink,) and "omi ekan-ogi" (Sour water from 3 days fermented milled maize). Leaves were dried and powdered before being soaked in solvents for 3 days. Another traditional method of extraction by squeezing raw juice from the leaves was also employed. All extracts were lyophilized. These extracts were tested against some gram-negative organisms (Escherichia coli ATCC 25922, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Shigella flexneri, Salmonella paratyphi, Citrobacter spp); gram-positive organisms Staphylococcus aureus ATCC 25213, Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis) and a fungus (Candida albicans). Agar well diffusion and broth dilution methods were used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) at concentrations of 512 mg/ml to 4 mg/ml. All the organisms except Candida albicans were susceptible to the extracts obtained from the traditional method. The squeezed-leaf juice of Kalanchoe crenata was the most active one with MIC of 8 mg/ml against Pseudomonas aeruginosa, Klebsiella pneumoniae and Bacillus subtilis, 32 mg/ml against Shigella flexneri, 64 mg/ml against Escherichia coli and 128 mg/ml against the control strain Staphylococcus aureus while its MBC is 256 mg/ml against these organisms except Bacillus subtilis and Klebsiella pneumoniae. The gram-positive organisms were more sensitive to the methanol and local gin-extract of Bryophyllum pinnatum. Extracts from other solvents showed moderate to weak activity. PMID:20161897

  17. How adaptable is the hydraulic system of European beech in the face of climate change-related precipitation reduction?

    PubMed

    Schuldt, Bernhard; Knutzen, Florian; Delzon, Sylvain; Jansen, Steven; Müller-Haubold, Hilmar; Burlett, Régis; Clough, Yann; Leuschner, Christoph

    2016-04-01

    Climate warming will increase the drought exposure of many forests world-wide. It is not well understood how trees adapt their hydraulic architecture to a long-term decrease in water availability. We examined 23 traits characterizing the hydraulic architecture and growth rate of branches and the dependent foliage of mature European beech (Fagus sylvatica) trees along a precipitation gradient (855-594 mm yr(-1) ) on uniform soil. A main goal was to identify traits that are associated with xylem efficiency, safety and growth. Our data demonstrate for the first time a linear increase in embolism resistance with climatic aridity (by 10%) across populations within a species. Simultaneously, vessel diameter declined by 7% and pit membrane thickness (Tm ) increased by 15%. Although specific conductivity did not change, leaf-specific conductivity declined by 40% with decreasing precipitation. Of eight plant traits commonly associated with embolism resistance, only vessel density in combination with pathway redundancy and Tm were related. We did not confirm the widely assumed trade-off between xylem safety and efficiency but obtained evidence in support of a positive relationship between hydraulic efficiency and growth. We conclude that the branch hydraulic system of beech has a distinct adaptive potential to respond to a precipitation reduction as a result of the environmental control of embolism resistance. PMID:26720626

  18. Effects of stoichiometry and temperature perturbations on beech litter decomposition, enzyme activities and protein expression

    NASA Astrophysics Data System (ADS)

    Keiblinger, K. M.; Schneider, T.; Roschitzki, B.; Schmid, E.; Eberl, L.; Hämmerle, I.; Leitner, S.; Richter, A.; Wanek, W.; Riedel, K.; Zechmeister-Boltenstern, S.

    2011-12-01

    Microbes are major players in leaf litter decomposition and therefore advances in the understanding of their control on element cycling are of paramount importance. Our aim was to investigate the influence of leaf litter stoichiometry in terms of carbon (C) : nitrogen (N) : phosphorus (P) on the decomposition process, and to follow changes in microbial community structure and function in response to temperature-stress treatments. To elucidate how the stoichiometry of beech litter (Fagus sylvatica L.) and stress treatments interactively affect the decomposition processes, a terrestrial microcosm experiment was conducted. Beech litter from different Austrian sites covering C:N ratios from 39 to 61 and C:P ratios from 666 to 1729 were incubated at 15 °C and 60% moisture for six months. Part of the microcosms were then subjected to severe changes in temperature (+30 °C and -15 °C) to monitor the influence of temperature stress. Extracellular enzyme activities were assayed and respiratory activities measured. A semi-quantitative metaproteomics approach (1D-SDS PAGE combined with liquid chromatography and tandem mass-spectrometry; unique spectral counting) was employed to investigate the impact of the applied stress treatments in dependency of litter stoichiometry on structure and function of the decomposing community. In litter with narrow C:nutrient ratios microbial decomposers were most abundant. Cellulase, chitinase, phosphatase and protease activity decreased after heat and frost treatments. Decomposer communities and specific functions varied with site i.e. stoichiometry. The applied stress evoked strong changes of enzyme activities, dissolved organic nitrogen and litter pH. Freeze treatments resulted in a decline in residual plant litter material, and increased fungal abundance indicating slightly accelerated decomposition. Overall, we could detect a strong effect of litter stoichiometry on microbial community structure as well as function. Temperature

  19. Beech T-34C Turbo Mentor

    NASA Technical Reports Server (NTRS)

    1978-01-01

    While most often flown as a photo chase aircraft, the Beech T-34C Turbo Mentor has performed research itself, notably with a laminar flow gloved wing. The aircraft is equipped with a luggage pod under its starboard wing. In 1989, the T-34 was used to sample Space Shuttle exhaust during mission STS-34.

  20. Molecular organization of the 25S-18S rDNA IGS of Fagus sylvatica and Quercus suber: a comparative analysis.

    PubMed

    Inácio, Vera; Rocheta, Margarida; Morais-Cecílio, Leonor

    2014-01-01

    The 35S ribosomal DNA (rDNA) units, repeated in tandem at one or more chromosomal loci, are separated by an intergenic spacer (IGS) containing functional elements involved in the regulation of transcription of downstream rRNA genes. In the present work, we have compared the IGS molecular organizations in two divergent species of Fagaceae, Fagus sylvatica and Quercus suber, aiming to comprehend the evolution of the IGS sequences within the family. Self- and cross-hybridization FISH was done on representative species of the Fagaceae. The IGS length variability and the methylation level of 18 and 25S rRNA genes were assessed in representatives of three genera of this family: Fagus, Quercus and Castanea. The intergenic spacers in Beech and Cork Oak showed similar overall organizations comprising putative functional elements needed for rRNA gene activity and containing a non-transcribed spacer (NTS), a promoter region, and a 5'-external transcribed spacer. In the NTS: the sub-repeats structure in Beech is more organized than in Cork Oak, sharing some short motifs which results in the lowest sequence similarity of the entire IGS; the AT-rich region differed in both spacers by a GC-rich block inserted in Cork Oak. The 5'-ETS is the region with the higher similarity, having nonetheless different lengths. FISH with the NTS-5'-ETS revealed fainter signals in cross-hybridization in agreement with the divergence between genera. The diversity of IGS lengths revealed variants from ∼ 2 kb in Fagus, and Quercus up to 5.3 kb in Castanea, and a lack of correlation between the number of variants and the number of rDNA loci in several species. Methylation of 25S Bam HI site was confirmed in all species and detected for the first time in the 18S of Q. suber and Q. faginea. These results provide important clues for the evolutionary trends of the rDNA 25S-18S IGS in the Fagaceae family. PMID:24893289

  1. Biomass in Serbia - potential of beech forests

    NASA Astrophysics Data System (ADS)

    Brasanac-Bosanac, Lj.; Cirkovic-Mitrovic, T.; Popovic, V.; Jokanovic, D.

    2012-04-01

    As for the renewable sources for energy production, biomass from forests and wood processing industry comes to the second place. The woody biomass accounts for 1.0 Mtoe, that is equivalent with 1.0 Mtoe of oil. Due to current evaluations, the greatest part of woody biomass would be used for briquettes and pallets production. As the biomass from forests is increasingly becoming the interest of national and international market, a detailed research on overall potential of woody supply from Serbian forests is required. Beech forests account for 29.4 % of forest cover of Serbia. They also have the greatest standing volume (42.4 % of the overall standing volume) and the greatest mean annual increment (32.3 %)(Bankovic,et.al.2009). Herewith, the aim of this poster is to determine the long-term biomass production of these forests.For this purpose a management unit called Lomnicka reka has been chosen. As these beech forests have similar structural development, this location is considered representative for whole Serbia. DBH of all trees were measured with clipper and the accuracy of 0.01 mm, and the heights with a Vertex 3 device (with accuracy of 0.1 m). All measurements were performed on the fields each 500 m2 (square meters). The overall quantity of root biomass was calculated using the allometric equations. The poster shows estimated biomass stocks of beech forests located in Rasina area. Dates are evaluated using non-linear regression (Wutzler,T.et.al.2008). Biomass potential of Serbian beech forests will enable the evaluation of long-term potential of energy generation from woody biomass in agreement with principles of sustainable forest management. The biomass from such beech forests can represent an important substitution for energy production from fossil fuels (e.g. oil) and herewith decrease the CO2 emissions.

  2. Classifying Oriental Beech (Fagus orientalis Lipsky.) Forest Sites Using Direct, Indirect and Remote Sensing Methods: A Case Study from Turkey

    PubMed Central

    Günlü, Alkan; Baskent, Emin Zeki; Kadiogullari, Ali İhsan; Ercanli, İlker

    2008-01-01

    Determining the productivity of forest sites through various classification techniques is important for making appropriate forest management decisions. Forest sites were classified using direct and indirect (site index) and remote sensing (Landsat 7 ETM and Quickbird satellite image) methods. In the direct method, forest site classifications were assigned according to edafic (soil properties), climate (precipitation and temperature) and topographic (altitude, slope, aspect and landform) factors. Five different forest site classes (dry, moderate fresh, fresh, moist and highly moist) were determined. In the indirect method, the guiding curve was used to generate anamorphic site index (SI) equations resulting in three classes; good (SI=I-II), medium (SI=III) and poor (SI=IV-V). Forest sites were also determined with a remote sensing method (RSM) using supervised classification of Landsat 7 ETM and Quickbird satellite images with a 0.67 kappa statistic value and 73.3% accuracy assessments; 0.88 kappa statistic value and 90.7% accuracy assessments, respectively. Forest sites polygon themes obtained from the three methods were overlaid and areas in the same classes were computed with Geographic Information Systems (GIS). The results indicated that direct and SI methods were consistent as a 3% dry site (19.0 ha) was exactly determined by both the direct and SI methods as a site class IV. Comparison of SI and RMS methods indicated a small difference as the area was highly homogeneous and unmanaged. While 15.4 ha area (open and degraded areas) was not determined by SI but RSM. A 19.0 ha (100%) poor site was determined by the SI method, 14.9 ha (78%) poor site was in Landsat 7 ETM satellite image and 17.4 ha (92%) poor site in Quickbird satellite image. The relationship between direct and SI methods were statistically analyzed using chi-square test. The test indicated a statistically significant relationships between forest sites determined by direct method and Quicbird satellite image (χ2 = 36.794; df = 16; p = 0.002), but no significant relationships with Landsat 7 ETM satellite image (χ2 = 22.291; df = 16; p = 0.134). Moderate association was found between SI method and direct method (χ2 = 16.724; df = 8; p = 0.033).

  3. Effect of methanolic fraction of Kalanchoe crenata on metabolic parameters in adriamycin-induced renal impairment in rats

    PubMed Central

    Kamgang, René; Foyet, Angèle F.; Essame, Jean-Louis O.; Ngogang, Jeanne Y.

    2012-01-01

    Objectives: To investigate the effect of Kalanchoe crenata methanolic fraction (MEKC) on proteinuria, glucosuria, and some other biochemical parameters in adriamycin-induced renal impairment in rats. Materials and Methods: Ether anesthetized rats received three intravenous injections (days 0, 14, and 28) of 2 mg/kg body weight of adriamycin. Repeated doses of the extract (0, 50, and 68 mg/kg b.w.) and losartan (10 mg/kg b.w.) were administered orally once daily, for 6 weeks, to these rats. Kidney functions were assessed through biochemical parameters. Results: MEKC decreased proteinuria and also the urinary excretion of creatinine, glucose, and urea significantly in diseased rats. A decrease in serum levels of creatinine, urea, potassium, alkaline phosphatase, conjugate bilirubin, and alanine transaminase level was also recorded in nephropathic rats, but plasma levels of uric acid and glucose remained unchanged. Moreover, the plant extract markedly (P < 0.05) increased plasma sodium and decreased (P < 0.01) the urinary sodium and potassium levels. Conclusions: The results indicated that the treatment with the methanolic fraction of K. crenata may improve proteinuria and all other symptoms due to adriamycin-induced nephropathy and, more than losartan, could ameliorate kidney and liver functions. K. crenata could be a potential source of new oral antinephropathic drug. PMID:23112414

  4. Validation of QTLs for Orobanche crenata resistance in faba bean (Vicia faba L.) across environments and generations.

    PubMed

    Díaz-Ruiz, Ramón; Torres, A M; Satovic, Z; Gutierrez, M V; Cubero, J I; Román, Belén

    2010-03-01

    Broomrape (Orobanche crenata Forsk.) is a major root-parasite of faba bean (Vicia faba L.), that seriously limits crop cultivation in the whole Mediterranean area. This parasitic weed is difficult to control, difficult to evaluate and the resistance identified so far is of polygenic nature. This study was conducted to identify genetic regions associated with broomrape resistance in recombinant inbred lines (RILs) and to validate their previous location in the original F(2) population derived from the cross between lines Vf6 and Vf136. A progeny consisting of 165 F(6) RILs was evaluated in three environments across two locations in 2003 and 2004. Two hundred seventy seven molecular markers were assigned to 21 linkage groups (9 of them assigned to specific chromosomes) that covered 2,856.7 cM of the V. faba genome. The composite interval mapping on the F(6) map detected more quantitative trait loci (QTL) than in the F(2) analysis. In this sense, four QTLs controlling O. crenata resistance (Oc2-Oc5) were identified in the RI segregant population in three different environments. Only Oc1, previously reported in the F(2) population, was not significant in the advanced lines. Oc2 and Oc3 were found to be associated with O. crenata resistance in at least two of the three environments, while the remaining two, Oc4 and Oc5, were only detected in Córdoba-04 and Mengíbar-04 and seemed to be environment dependent. PMID:19956921

  5. Seasonal dynamics in the stable carbon isotope composition δ¹³C from non-leafy branch, trunk and coarse root CO₂ efflux of adult deciduous (Fagus sylvatica) and evergreen (Picea abies) trees.

    PubMed

    Kuptz, Daniel; Matyssek, Rainer; Grams, Thorsten E E

    2011-03-01

    Respiration is a substantial driver of carbon (C) flux in forest ecosystems and stable C isotopes provide an excellent tool for its investigation. We studied seasonal dynamics in δ¹³C of CO₂ efflux (δ¹³C(E)) from non-leafy branches, upper and lower trunks and coarse roots of adult trees, comparing deciduous Fagus sylvatica (European beech) with evergreen Picea abies (Norway spruce). In both species, we observed strong and similar seasonal dynamics in the δ¹³C(E) of above-ground plant components, whereas δ¹³C(E) of coarse roots was rather stable. During summer, δ¹³C(E) of trunks was about -28.2‰ (Beech) and -26.8‰ (Spruce). During winter dormancy, δ¹³C(E) increased by 5.6-9.1‰. The observed dynamics are likely related to a switch from growth to starch accumulation during fall and remobilization of starch, low TCA cycle activity and accumulation of malate by PEPc during winter. The seasonal δ¹³C(E) pattern of branches of Beech and upper trunks of Spruce was less variable, probably because these organs were additionally supplied by winter photosynthesis. In view of our results and pervious studies, we conclude that the pronounced increases in δ¹³C(E) of trunks during the winter results from interrupted access to recent photosynthates. PMID:21054435

  6. Influence of Climatic Type of Year on Beech and Scots Pine Eustress

    NASA Astrophysics Data System (ADS)

    Lyubenova, Mariyana; Chikalanov, Alexandre; van Bodegom, Peter; Kattge, Jens; Popova, Silvia; Zlateva, Plamena

    2016-04-01

    The present study deals with the relationships of climate types and the periods with low radial stem growth of black pine and beech locations in Europe. The identification of climatic types (CT) and eustress caused CT, their relative participation in the period of 1901-2009 by locations, the manifestation of main adverse type, led periodically to reduction of tree ring width, as well as the comparison of obtained types by precipitations and the SPI classes were the subjects of investigation. The analyses demonstrated that despite the local differences, the stress impact of dry and wet years, especially if they are accompanied by the cold or hot regimes, is well expressed. The successive changes of climate types at least two years before the eustress year are also relevant. The application of climatic types to study the relationship with trees eustress is more applicable when there are no large deviations in temperatures or precipitations by years and locations. The demonstrated holistic analyses are applicable for the forest areas monitoring and management. Key words Pinus sylvestris L., Fagus sylvatica L., climatic type, SPI, eustress, SPPAM application, SPI

  7. The influence of the soil on spring and autumn phenology in European beech.

    PubMed

    Arend, Matthias; Gessler, Arthur; Schaub, Marcus

    2016-01-01

    Tree phenology is a key discipline in forest ecology linking seasonal fluctuations of photoperiod and temperature with the annual development of buds, leaves and flowers. Temperature and photoperiod are commonly considered as main determinants of tree phenology while little is known about interactions with soil chemical characteristics. Seedlings of 12 European beech (Fagus sylvatica L.) provenances were transplanted in 2011 to model ecosystems and grown for 4 years on acidic or calcareous forest soil. Spring bud burst and autumnal leaf senescence were assessed in the last 2 years, 2013 and 2014, which were characterized by contrasting annual temperatures with a very warm spring and autumn in 2014. In 2013, spring bud burst and autumnal leaf senescence were advanced on acidic soil with a greater effect on leaf senescence. Hence, the vegetation period 2013 was shorter on this soil type compared with that on calcareous soil. In 2014, a similar soil effect was observed for spring bud burst while autumnal leaf senescence and the length of the vegetation period were not affected, probably due to interferences with the overall extension of the vegetation period in this exceptionally warm year. A different soil responsiveness was observed among the provenances with early bursting or senescing provenances being more sensitive than late bursting or senescing provenances. The findings of this study highlight the soil as an ecologically relevant factor in tree phenology and might help explain existing uncertainties in current phenology models. PMID:26420791

  8. Dynamic of Plant Composition and Regeneration following Windthrow in a Temperate Beech Forest

    PubMed Central

    Mollaei Darabi, Sakineh; Kooch, Yahya; Hosseini, Seyed Mohsen

    2014-01-01

    The effects of soil pedoturbation (i.e., pit and mound microtopography, PM) on development of herbaceous plant species and woody species regeneration were examined in a temperate beech forest (Fagus orientalis Lipsky) in northern Iran. We recorded the vegetation in 20 pairs of disturbed and adjacent undisturbed plots and established a chronosequence of PM ages to study the effect of time since microsite formation on cover percent of herbaceous plants and woody regeneration status. According to our findings, Carex acutiformis L., Sambucus ebulus L., Brachypodium pinnatum L., and Cyclamen coum L. are found only in the PM microsites, whereas the Equisetum ramosissimum L. is recorded only under closed canopy. The coverage percent of Rubus caesius L. increased in PM microsites compared to closed canopy intensively. In addition, Albizia julibrissin Durazz. is detected in PM microsite, whereas the Acer cappadocicum B. and Prunus persica L. species were recorded only under closed canopy. We found significant differences in understory species diversity between different ages of PM, and disturbed and adjacent undisturbed plots. Our study supports that the PM complex will create a mosaic of environmental conditions. This environmental heterogeneity could be responsible for the diversity of herbaceous plant species and regeneration of woody species. PMID:27379260

  9. Dynamic of Plant Composition and Regeneration following Windthrow in a Temperate Beech Forest.

    PubMed

    Mollaei Darabi, Sakineh; Kooch, Yahya; Hosseini, Seyed Mohsen

    2014-01-01

    The effects of soil pedoturbation (i.e., pit and mound microtopography, PM) on development of herbaceous plant species and woody species regeneration were examined in a temperate beech forest (Fagus orientalis Lipsky) in northern Iran. We recorded the vegetation in 20 pairs of disturbed and adjacent undisturbed plots and established a chronosequence of PM ages to study the effect of time since microsite formation on cover percent of herbaceous plants and woody regeneration status. According to our findings, Carex acutiformis L., Sambucus ebulus L., Brachypodium pinnatum L., and Cyclamen coum L. are found only in the PM microsites, whereas the Equisetum ramosissimum L. is recorded only under closed canopy. The coverage percent of Rubus caesius L. increased in PM microsites compared to closed canopy intensively. In addition, Albizia julibrissin Durazz. is detected in PM microsite, whereas the Acer cappadocicum B. and Prunus persica L. species were recorded only under closed canopy. We found significant differences in understory species diversity between different ages of PM, and disturbed and adjacent undisturbed plots. Our study supports that the PM complex will create a mosaic of environmental conditions. This environmental heterogeneity could be responsible for the diversity of herbaceous plant species and regeneration of woody species. PMID:27379260

  10. Applying Ada to Beech Starship avionics

    NASA Technical Reports Server (NTRS)

    Funk, David W.

    1986-01-01

    As Ada solidified in its development, it became evident that it offered advantages for avionics systems because of it support for modern software engineering principles and real time applications. An Ada programming support environment was developed for two major avionics subsystems in the Beech Starship. The two subsystems include electronic flight instrument displays and the flight management computer system. Both of these systems use multiple Intel 80186 microprocessors. The flight management computer provides flight planning, navigation displays, primary flight display of checklists and other pilot advisory information. Together these systems represent nearly 80,000 lines of Ada source code and to date approximately 30 man years of effort. The Beech Starship avionics systems are in flight testing.

  11. Chemical composition and biological activities of essential oil from Hyptis crenata growing in the Brazilian cerrado.

    PubMed

    Violante, Ivana Maria Póvoa; Garcez, Walmir Silva; Barbosa, Carolina da Silva; Garcez, Fernanda Rodrigues

    2012-10-01

    Essential oils from species of the genus Hyptis are well-known for their significant biological properties, including antimicrobial and acaricidal activities. The essential oil from the aerial parts of H. crenata was obtained by hydrodistillation; bomeol (17.8%), 1,8-cineol (15.6%) and p-cimene (7.9%) were characterized by GC-MS as its major constituents. The essential oil was evaluated in vitro for its antimicrobial activities against six fungal and five bacterial strains, by measuring the respective MICs, MFCs and MBCs, using broth microdilution methods. The strongest bactericidal activities were shown against Staphylococcus aureus and Enterococcus faecalis, while the strongest fungicidal activities were against Cryptococcus neoformans, Candida glabrata and Candida tropicalis. The oil was also assessed for its anti-tick properties and, at a concentration of 2.5%, it significantly inhibited in vivo oviposition of engorged females of the cattle tick Rhipicephalus (Boophilus) microplus, using the adult immersion test., with an effectiveness of 94.4%. PMID:23157018

  12. Carbon flux to woody tissues in a beech/spruce forest during summer and in response to chronic O3 exposure

    NASA Astrophysics Data System (ADS)

    Ritter, W.; Andersen, C. P.; Matyssek, R.; Grams, T. E. E.

    2011-11-01

    The present study compares the dynamics in carbon (C) allocation of adult deciduous beech (Fagus sylvatica) and evergreen spruce (Picea abies) during summer and in response to seven-year-long exposure with twice-ambient ozone (O3) concentrations (2 × O3). Focus was on the respiratory turn-over and translocation of recent photosynthates at various positions along the stems, coarse roots and soils. The hypotheses tested were that (1) 2 × O3 decreases the allocation of recent photosynthates to CO2 efflux of stems and coarse roots of adult trees, and that (2) according to their different O3 sensitivities this effect is stronger in beech than in spruce. Labeling of whole tree canopies was applied by releasing 13C depleted CO2 (δ13C of -46.9‰) using a free-air stable carbon isotope approach. Canopy air δ13C was reduced for about 2.5 weeks by ca. 8‰ in beech and 6‰ in spruce while the increase in CO2 concentration was limited to about 110 μl l-1 and 80 μl l-1, respectively. At the end of the labeling period, δ13C of stem CO2 efflux and phloem sugars was reduced to a similar extend by ca. 3-4‰ (beech) and ca. 2-3‰ (spruce). The fraction of labeled C (fE,new) in stem CO2 efflux amounted to 0.3 to 0.4, indicating slow C turnover of the respiratory supply system in both species. Elevated O3 slightly stimulated the allocation of recently fixed photosynthates to stem and coarse root respiration in spruce (rejection of hypothesis I for spruce), but resulted in a significant reduction in C flux in beech (acceptance of hypotheses I and II). The distinct decrease in C allocation to beech stems indicates the potential of chronic O3 stress to substantially mitigate the C sink strength of trees on the long-term scale.

  13. Carbon flux to woody tissues in a beech/spruce forest during summer and in response to chronic elevated O3 exposure

    NASA Astrophysics Data System (ADS)

    Ritter, W.; Andersen, C. P.; Matyssek, R.; Grams, T. E. E.

    2011-04-01

    The present study compares the dynamics in carbon (C) allocation of adult deciduous beech (Fagus sylvatica) and evergreen spruce (Picea abies) during summer and in response to seven-year-long exposure with twice-ambient ozone (O3) concentrations (2 × O3). Focus was on the respiratory turn-over and translocation of recent photosynthates at various positions along the stems, coarse roots and soils. The hypotheses tested were that (1) 2 × O3 decreases the allocation of recent photosynthates to CO2 efflux of stems and coarse roots of adult trees, and that (2) according to their different O3 sensitivities this effect is stronger in beech than in spruce. Labeling of whole tree canopies was applied by releasing 13C depleted CO2 (δ13C of -46.9‰) using a free-air stable carbon isotope approach. Canopy air δ13C was reduced for about 2.5 weeks by ca. 8‰ in beech and 6‰ in spruce while the increase in CO2 concentration was limited to about 110 μL L-1 and 80 μL L-1, respectively. At the end of the labeling period, δ13C of stem CO2 efflux and phloem sugars was reduced to a similar extend by ca. 3-4‰ (beech) and ca. 2-3‰ (spruce). The fraction of labeled C (fE,new) in stem CO2 efflux amounted to 0.3 to 0.4, indicating slow C turnover of the respiratory supply system in both species. Elevated O3 slightly stimulated the allocation of recently fixed photosynthates to stem and coarse root respiration in spruce (rejection of hypothesis I for spruce), but resulted in a significant reduction in C flux in beech (acceptance of hypotheses I and II). The distinct decreased in C allocation to beech stems indicates the potential of chronic O3 stress to substantially mitigate the C sink strength of trees on the long-term scale.

  14. Spatio-temporal Variability of Stemflow Volume in a Beech-Yellow Poplar Forest in Relation to Tree Species and Size

    NASA Astrophysics Data System (ADS)

    Levia, D. F.; van Stan, J. T.; Mage, S.; Hauske, P. W.

    2009-05-01

    Stemflow is a localized point input at the base of trees that can account for more than 10% of the incident gross precipitation in deciduous forests. Despite the fact that stemflow has been documented to be of hydropedological importance, affecting soil moisture patterns, soil erosion, soil chemistry, and the distribution of understory vegetation, our current understanding of the temporal variability of stemflow yield is poor. The aim of the present study, conducted in a beech-yellow poplar forest in northeastern Maryland (39°42'N, 75°50'W), was to better understand the temporal and variability of stemflow production from Fagus grandifolia Ehrh. (American beech) and Liriodendron tulipifera L. (yellow poplar) in relation to meteorological conditions and season in order to better assess its importance to canopy-soil interactions. The experimental plot had a stand density of 225 trees/ha, a stand basal area of 36.8 sq. m/ha, a mean dbh of 40.8 cm, and a mean tree height of 27.8 m. The stand leaf area index (LAI) is 5.3. Yellow poplar and beech constitute three- quarters of the stand basal area. Using a high resolution (5 min) sequential stemflow sampling network, consisting of tipping-bucket gauges interfaced with a Campbell CR1000 datalogger, the temporal variability of stemflow yield was examined. Beech produced significantly larger stemflow amounts than yellow poplar. The amount of stemflow produced by individual beech trees in 5 minute intervals reached three liters. Stemflow yield and funneling ratios decreased with increasing rain intensity. Temporal variability of stemflow inputs were affected by the nature of incident gross rainfall, season, tree species, tree size, and bark water storage capacity. Stemflow was greater during the leafless period than full leaf period. Stemflow yield was greater for larger beech trees and smaller yellow poplar trees, owing to differences in bark water storage capacity. The findings of this study indicate that stemflow has a

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

    PubMed

    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

  16. Climate Change Impairs Nitrogen Cycling in European Beech Forests

    PubMed Central

    Dannenmann, Michael; 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

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Effects of stoichiometry and temperature perturbations on beech leaf litter decomposition, enzyme activities and protein expression

    NASA Astrophysics Data System (ADS)

    Keiblinger, K. M.; Schneider, T.; Roschitzki, B.; Schmid, E.; Eberl, L.; Hämmerle, I.; Leitner, S.; Richter, A.; Wanek, W.; Riedel, K.; Zechmeister-Boltenstern, S.

    2012-11-01

    Microbes are major players in leaf litter decomposition and therefore advances in the understanding of their control on element cycling are of paramount importance. Our aim was to investigate the influence of leaf litter stoichiometry in terms of carbon (C) : nitrogen (N) : phosphorus (P) ratios on the decomposition processes and to track changes in microbial community structures and functions in response to temperature stress treatments. To elucidate how the stoichiometry of beech leaf litter (Fagus sylvatica L.) and stress treatments interactively affect the microbial decomposition processes, a terrestrial microcosm experiment was conducted. Beech litter from different Austrian sites covering C:N ratios from 39 to 61 and C:P ratios from 666 to 1729 were incubated at 15 °C and 60% moisture for six months. Part of the microcosms were then subjected to severe changes in temperature (+30 °C and -15 °C) to monitor the influence of temperature stress. Extracellular enzyme activities were assayed and respiratory activities measured. A semi-quantitative metaproteomics approach (1D-SDS PAGE combined with liquid chromatography and tandem mass spectrometry; unique spectral counting) was employed to investigate the impact of the applied stress treatments in dependency of litter stoichiometry on structure and function of the decomposing community. In litter with narrow C:nutrient (C:N, C:P) ratios, microbial decomposers were most abundant. Cellulase, chitinase, phosphatase and protease activity decreased after heat and freezing treatments. Decomposer communities and specific functions varied with site, i.e. stoichiometry. The applied stress combined with the respective time of sampling evoked changes of enzyme activities and litter pH. Freezing treatments resulted in a decline in residual plant litter material and increased fungal abundance, indicating slightly accelerated decomposition. Overall, a strong effect of litter stoichiometry on microbial community structures and

  20. A Technique to Screen American Beech for Resistance to the Beech Scale Insect (Cryptococcus fagisuga Lind.)

    PubMed Central

    Koch, Jennifer L.; Carey, David W.

    2014-01-01

    Beech bark disease (BBD) results in high levels of initial mortality, leaving behind survivor trees that are greatly weakened and deformed. The disease is initiated by feeding activities of the invasive beech scale insect, Cryptococcus fagisuga, which creates entry points for infection by one of the Neonectria species of fungus. Without scale infestation, there is little opportunity for fungal infection. Using scale eggs to artificially infest healthy trees in heavily BBD impacted stands demonstrated that these trees were resistant to the scale insect portion of the disease complex1. Here we present a protocol that we have developed, based on the artificial infestation technique by Houston2, which can be used to screen for scale-resistant trees in the field and in smaller potted seedlings and grafts. The identification of scale-resistant trees is an important component of management of BBD through tree improvement programs and silvicultural manipulation. PMID:24894494

  1. Comparison of forest litter interception model of sessile oak and beech forest

    NASA Astrophysics Data System (ADS)

    Zagyvai-Kiss, Katalin Anita; Kalicz, Péter; Gribovszki, Zoltán

    2014-05-01

    Forest hydrological models help us to understand the natural processes in forest. The forest has huge active surface available for evaporation processes. The amount of precipitation decreases after reaching the canopy. The throughfall arrives at the forest litter. The rainfall retention of the litter is the litter interception. In this paper a hydrologic model was employed for estimation of forest litter interception of a middle-aged sessile oak (Quercus petraea) and beech (Fagus sylvatica) stand. The discussed forest litter interception is an important element of the water balance of the forest and can be an important parameter of the rainfall runoff models in forested area. The research catchment in Hidegvíz Valley near Sopron provides valuable data for testing such kind of hydrologic models. Antecedent water content and the storage capacity of the forest litter are the main parameters of the model. The antecedent water content of the litter was estimated by the daily precipitation and temperature data, collected in Hidegvíz Valley research catchment in a three years long measurement period (2006-2008). The measurements were done by own developed instrument, where the undisturbed forest litter samples are enclosed in frames and it was measured on stationary place in every time step. Our model estimation for litter interception was 5-7% of gross precipitation. Acknowledgements: The research was supported by TÁMOP-4.2.2.A-11/1/KONV-2012-0004. The research of Zoltán Gribovszki was supported by the European Union and the State of Hungary, co-financed by the European Social Fund in the framework of TÁMOP 4.2.4. A/2-11-1-2012-0001 'National Excellence Program'.

  2. Spatial variability of microbial activity and substrate utilization patterns in top- and subsoils under European beech

    NASA Astrophysics Data System (ADS)

    Niebuhr, Jana; Heinze, Stefanie; Mikutta, Robert; Mueller, Carsten W.; Preusser, Sebastian; Marschner, Bernd

    2014-05-01

    The role of subsoils in the global carbon cycle is poorly understood and probably underestimated. This is due to an incomplete understanding of processes and mechanisms that influence carbon storage and decomposition in deeper soil horizons. Microbial communities play an important role in these processes, as their presence, structure and function are crucial for the decomposition and/or stabilization of organic compounds. In this study, carried out in a European beech (Fagus sylvatica L.) forest on a podzolic Cambisol near Hannover, the spatial variability of microbial activity and substrate utilization patterns were investigated in the subsoil. For this purpose, samples were taken from regular grids at dm distances in three soil profiles of 1.85 m depth and 3.15 m length, totaling 192 soil samples. Activities of 9 extracellular enzymes of the C-, S-, P- and N-cycle were determined with a multi-substrate enzymatic assay and for substrate utilization patterns the MicroRespTM method was applied. The results showed a strong decline of microbial activity from topsoil to subsoil. Enzyme activities varied greatly at the dm scale. The correlation of the variability of both microbial activity and substrate utilization patterns with depth and soil parameters such as pH, soil water content, total and dissolved organic carbon was tested with a principal component analysis. Existing dependencies of the variabilities on these parameters help to verify the hypotheses that microbial activity is spatially highly variable in the subsoil and this variability is due to the existence of certain hot spots of substrate availability and that outside these 'hot spots' the microbial activity and thus the decomposition of SOM are mainly limited by substrate availability.

  3. Particulate matter in terrestrial solutions: insights from a European beech forest in Germany

    NASA Astrophysics Data System (ADS)

    Levia, Delphis; Michalzik, Beate; Bischoff, Sebastian; Näthe, Kerstin; Gruselle, Marie-Cecile; Legates, David; Richter, Susanne

    2015-04-01

    Particulate matter (PM) can affect the functional ecology and health of forest ecosystems. Nonetheless, the cycling of particulate matter is usually neglected in studies examining the biogeochemistry of forest ecosystems. The size and shape of PM has been documented to influence both its impaction on forest canopies and its biogeochemical reactivity. So what is the size and shape of PM in bulk precipitation, throughfall, stemflow, and Oa solution? An answer to this question is of prime importance to those wishing to better model the biogeochemistry of forests. This presentation examines the nature of PM in terrestrial solutions from a European beech (Fagus sylvatica L.) in east-central Germany during the leafed and leafless periods. Scanning electron microscopy, image processing, and data analysis permitted quantification of the size and shape of PM in forest solutions. Building upon the work of Levia et al. [2013]* who quantified the diameter distributions of 43,278 individual particulates in bulk precipitation, throughfall, stemflow, and Oa soil solution, this work delves into surface area, roundness, and perimeter of PM in terrestrial solutions. Initial analyses have revealed that there are marked differences in the geometry of PM in bulk precipitation, throughfall, stemflow, and Oa solutions with implications for biogeochemical modeling of PM flux in forests. --------------- * Levia, D.F., Michalzik, B., Bischoff, S., Näthe, K., Legates, D.R., Gruselle, M.C-. and Richter, S. 2013. Measurement and modeling of diameter distributions of particulate matter in terrestrial solutions. Geophysical Research Letters 40(7): 1317-1321. [DOI: 10.1002/grl.50305] Funding note: This work was funded by the Alexander von Humboldt Foundation.

  4. Intraspecific Variation in Wood Anatomical, Hydraulic, and Foliar Traits in Ten European Beech Provenances Differing in Growth Yield

    PubMed Central

    Hajek, Peter; Kurjak, Daniel; von Wühlisch, Georg; Delzon, Sylvain; Schuldt, Bernhard

    2016-01-01

    In angiosperms, many studies have described the inter-specific variability of hydraulic-related traits and little is known at the intra-specific level. This information is however mandatory to assess the adaptive capacities of tree populations in the context of increasing drought frequency and severity. Ten 20-year old European beech (Fagus sylvatica L.) provenances representing the entire distribution range throughout Europe and differing significantly in aboveground biomass increment (ABI) by a factor of up to four were investigated for branch wood anatomical, hydraulic, and foliar traits in a provenance trial located in Northern Europe. We quantified to which extend xylem hydraulic and leaf traits are under genetic control and tested whether the xylem hydraulic properties (hydraulic efficiency and safety) trades off with yield and wood anatomical and leaf traits. Our results showed that only three out of 22 investigated ecophysiological traits showed significant genetic differentiations between provenances, namely vessel density (VD), the xylem pressure causing 88% loss of hydraulic conductance and mean leaf size. Depending of the ecophysiological traits measured, genetic differentiation between populations explained 0–14% of total phenotypic variation, while intra-population variability was higher than inter-population variability. Most wood anatomical traits and some foliar traits were additionally related to the climate of provenance origin. The lumen to sapwood area ratio, vessel diameter, theoretical specific conductivity and theoretical leaf-specific conductivity as well as the C:N-ratio increased with climatic aridity at the place of origin while the carbon isotope signature (δ13C) decreased. Contrary to our assumption, none of the wood anatomical traits were related to embolism resistance but were strong determinants of hydraulic efficiency. Although ABI was associated with both VD and δ13C, both hydraulic efficiency and embolism resistance were

  5. Intraspecific Variation in Wood Anatomical, Hydraulic, and Foliar Traits in Ten European Beech Provenances Differing in Growth Yield.

    PubMed

    Hajek, Peter; Kurjak, Daniel; von Wühlisch, Georg; Delzon, Sylvain; Schuldt, Bernhard

    2016-01-01

    In angiosperms, many studies have described the inter-specific variability of hydraulic-related traits and little is known at the intra-specific level. This information is however mandatory to assess the adaptive capacities of tree populations in the context of increasing drought frequency and severity. Ten 20-year old European beech (Fagus sylvatica L.) provenances representing the entire distribution range throughout Europe and differing significantly in aboveground biomass increment (ABI) by a factor of up to four were investigated for branch wood anatomical, hydraulic, and foliar traits in a provenance trial located in Northern Europe. We quantified to which extend xylem hydraulic and leaf traits are under genetic control and tested whether the xylem hydraulic properties (hydraulic efficiency and safety) trades off with yield and wood anatomical and leaf traits. Our results showed that only three out of 22 investigated ecophysiological traits showed significant genetic differentiations between provenances, namely vessel density (VD), the xylem pressure causing 88% loss of hydraulic conductance and mean leaf size. Depending of the ecophysiological traits measured, genetic differentiation between populations explained 0-14% of total phenotypic variation, while intra-population variability was higher than inter-population variability. Most wood anatomical traits and some foliar traits were additionally related to the climate of provenance origin. The lumen to sapwood area ratio, vessel diameter, theoretical specific conductivity and theoretical leaf-specific conductivity as well as the C:N-ratio increased with climatic aridity at the place of origin while the carbon isotope signature (δ(13)C) decreased. Contrary to our assumption, none of the wood anatomical traits were related to embolism resistance but were strong determinants of hydraulic efficiency. Although ABI was associated with both VD and δ(13)C, both hydraulic efficiency and embolism resistance were

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

    PubMed Central

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

    2016-01-01

    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. PMID:27302652

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

    PubMed

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

    2016-01-01

    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. PMID:27302652

  8. Differential stemflow yield from European beech saplings: the role and respective importance of individual canopy structure metrics

    NASA Astrophysics Data System (ADS)

    Levia, Delphis; Michalzik, Beate

    2013-04-01

    Stemflow yield from individual trees varies as a function of both meteorological conditions and canopy structure. The importance and differential effects of various metrics of canopy structure in relation to stemflow yield is inadequately understood and the subject of debate among forest hydrologists. It is possible to evaluate the role and respective importance of individual canopy structure metrics by holding meteorological conditions constant. Twelve isolated experimental European beech (Fagus sylvatica L.) saplings in Jena, Germany were exposed to identical meteorological conditions to examine the effects of canopy structure on stemflow production during the 2012 growing season. The canopy structure metrics being evaluated include: trunk diameter, trunk lean, tree height, projected crown area, branch inclination angle, branch count, and biomass (foliar and woody). Principal components analysis and multiple regression are utilized to determine the relative importance of different canopy structure metrics on stemflow yield. Experimental results will provide insight as to which metrics of canopy structure most strongly govern stemflow production. Ultimately, with a more thorough understanding of the unique contributions of various canopy structural metrics to stemflow yield, a useful conceptual guide of stemflow generation can be formulated on the basis of canopy structure for management purposes. Sponsor note: This research was funded by the Alexander von Humboldt Foundation.

  9. Competition for nitrogen between Fagus sylvatica and Acer pseudoplatanus seedlings depends on soil nitrogen availability

    PubMed Central

    Li, Xiuyuan; Rennenberg, Heinz; Simon, Judy

    2015-01-01

    Competition for nitrogen (N), particularly in resource-limited habitats, might be avoided by different N acquisition strategies of plants. In our study, we investigated whether slow-growing European beech and fast-growing sycamore maple seedlings avoid competition for growth-limiting N by different N uptake patterns and the potential alteration by soil N availability in a microcosm experiment. We quantified growth and biomass indices, 15N uptake capacity and N pools in the fine roots. Overall, growth indices, N acquisition and N pools in the fine roots were influenced by species-specific competition depending on soil N availability. With inter-specific competition, growth of sycamore maple reduced regardless of soil N supply, whereas beech only showed reduced growth when N was limited. Both species responded to inter-specific competition by alteration of N pools in the fine roots; however, sycamore maple showed a stronger response compared to beech for almost all N pools in roots, except for structural N at low soil N availability. Beech generally preferred organic N acquisition while sycamore maple took up more inorganic N. Furthermore, with inter-specific competition, beech had an enhanced organic N uptake capacity, while in sycamore maple inorganic N uptake capacity was impaired by the presence of beech. Although sycamore maple could tolerate the suboptimal conditions at the cost of reduced growth, our study indicates its reduced competitive ability for N compared to beech. PMID:25983738

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

    NASA Astrophysics Data System (ADS)

    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

  11. Subcellular Nutrient Element Localization and Enrichment in Ecto- and Arbuscular Mycorrhizas of Field-Grown Beech and Ash Trees Indicate Functional Differences

    PubMed Central

    Seven, Jasmin; Polle, Andrea

    2014-01-01

    Mycorrhizas are the chief organ for plant mineral nutrient acquisition. In temperate, mixed forests, ash roots (Fraxinus excelsior) are colonized by arbuscular mycorrhizal fungi (AM) and beech roots (Fagus sylvatica) by ectomycorrhizal fungi (EcM). Knowledge on the functions of different mycorrhizal species that coexist in the same environment is scarce. The concentrations of nutrient elements in plant and fungal cells can inform on nutrient accessibility and interspecific differences of mycorrhizal life forms. Here, we hypothesized that mycorrhizal fungal species exhibit interspecific differences in mineral nutrient concentrations and that the differences correlate with the mineral nutrient concentrations of their associated root cells. Abundant mycorrhizal fungal species of mature beech and ash trees in a long-term undisturbed forest ecosystem were the EcM Lactarius subdulcis, Clavulina cristata and Cenococcum geophilum and the AM Glomus sp. Mineral nutrient subcellular localization and quantities of the mycorrhizas were analysed after non-aqueous sample preparation by electron dispersive X-ray transmission electron microscopy. Cenococcum geophilum contained the highest sulphur, Clavulina cristata the highest calcium levels, and Glomus, in which cations and P were generally high, exhibited the highest potassium levels. Lactarius subdulcis-associated root cells contained the highest phosphorus levels. The root cell concentrations of K, Mg and P were unrelated to those of the associated fungal structures, whereas S and Ca showed significant correlations between fungal and plant concentrations of those elements. Our results support profound interspecific differences for mineral nutrient acquisition among mycorrhizas formed by different fungal taxa. The lack of correlation between some plant and fungal nutrient element concentrations may reflect different retention of mineral nutrients in the fungal part of the symbiosis. High mineral concentrations, especially of

  12. Trunk detail Prince William Forest Park American Beech , ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Trunk detail - Prince William Forest Park American Beech , Approximately one mile from visitor’s center, south bank of the south fork of Quantico Creek, about 75 yards upstream from its confluence with Quantico Creek, Near Birch Bluff Trail, Triangle, Prince William County, VA

  13. Wood energy fuel cycle optimization in beech and spruce forests

    NASA Astrophysics Data System (ADS)

    Meyer, Nickolas K.; Mina, Marco

    2012-03-01

    A novel synergistic approach to reducing emissions from residential wood combustion (RWC) is presented. Wood energy fuel cycle optimization (FCO) aims to provide cleaner burning fuels through optimization of forestry and renewable energy management practices. In this work, beech and spruce forests of average and high quality were modelled and analysed to determine the volume of fuel wood and its associated bark fraction produced during typical forestry cycles. Two separate fuel wood bark production regimes were observed for beech trees, while only one production regime was observed for spruce. The single tree and stand models were combined with existing thinning parameters to replicate existing management practices. Utilizing estimates of initial seedling numbers and existing thinning patterns a dynamic model was formed that responded to changes in thinning practices. By varying the thinning parameters, this model enabled optimization of the forestry practices for the reduction of bark impurities in the fuel wood supply chain. Beech forestry cycles responded well to fuel cycle optimization with volume reductions of bark from fuel wood of between ˜10% and ˜20% for average and high quality forest stands. Spruce, on the other hand, was fairly insensitive to FCO with bark reductions of 0-5%. The responsiveness of beech to FCO further supports its status as the preferred RWC fuel in Switzerland. FCO could easily be extended beyond Switzerland and applied across continental Europe and North America.

  14. Prince William Forest Park American Beech , Approximately one mile ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Prince William Forest Park American Beech , Approximately one mile from visitor’s center, south bank of the south fork of Quantico Creek, about 75 yards upstream from its confluence with Quantico Creek, Near Birch Bluff Trail, Triangle, Prince William County, VA

  15. Ammonia fluxes for beech forest in the leaf fall transition period - measurements and modeling

    NASA Astrophysics Data System (ADS)

    Hansen, K.; Sørensen, L.; Hertel, O.; Geels, C.; Skjøth, C. A.; Jensen, B.; Boegh, E.

    2012-12-01

    Deposition of atmospheric reactive nitrogen represents uncertainties for the prediction of future greenhouse gas exchange between land surfaces and the atmosphere. This is because the mechanisms describing nutritional effects are not well developed in climate and ecosystems models. Improving the understanding of biochemical feed-back mechanisms in the climate system and quantifying the magnitude of the NH3 flux in the biosphere-atmosphere system is therefore essential. In particular, more knowledge of the bi-directional ammonia (NH3) exchange between natural ecosystems and the atmosphere is needed. We investigated the NH3 exchange for deciduous forests in relation to leaf fall by studying the atmospheric NH3 fluxes throughout a 25 days period during autumn 2010 (21 October - 14 November) for the Danish beech (Fagus sylvatica) forest, Lille Bøgeskov. Vegetation status was observed using plant area index (PAI) and leaf area index (LAI). The atmospheric NH3 fluxes were measured using the relaxed eddy accumulation (REA) method and compared to NH3 denuder measurements. Model calculations were obtained using the Danish Ammonia MOdelling System (DAMOS). We found that 57.7% of the fluxes measured showed emission and 19.5% deposition. The mean NH3 flux was 0.087±0.19 μg NH3-N m-2 s-1. Measurements indicate a clear tendency of the flux going from negative (deposition) to positive (emission) fluxes of up to 0.96±0.40 μg NH3-N m-2 s-1 throughout the measurement period. In the leaf fall period (23 October - 8 November) the measured atmospheric NH3 concentration was increasing in relation to the increasing forest NH3 flux. The mean NH3 concentration was well simulated in DAMOS before leaf fall, but was underestimated following leaf fall. The results indicate that there is a missing contribution to atmospheric NH3 concentration from vegetative surfaces related to leaf fall of a relatively large magnitude in the model. This points to the need for representing forest leaf fall

  16. Climate variation and the stable carbon isotope composition of tree ring cellulose: an intercomparison of Quercus robur, Fagus sylvatica and Pinus silvestris

    NASA Astrophysics Data System (ADS)

    Hemming, D. L.; Switsur, V. R.; Waterhouse, J. S.; Heaton, T. H. E.; Carter, A. H. C.

    1998-02-01

    The relationship between climate parameters and the carbon stable isotope composition (δ13C), of annual tree ring cellulose is examined for three native British tree species; Common beech (Fagus sylvatica L.), Pedunculate oak (Quercus robur L.) and Scots pine (Pinus sylvestris L.). The last 100 annual tree rings of six trees, two of each species, were cut into slivers and the a-cellulose extracted. Annual δ13C values of each species were averaged to produce three species δ13C chronologies. These were compared with climate parameters from a nearby meteorological station. The carbon stable isotope discrimination (Δ13C) of pine is consistently lower, by approximately 2.5‰, than that of beech and oak. Although the exact cause of this offset cannot be identified, similar differences in carbon isotope ratios have been noted between other gymnosperm and angiosperm species and attributed to inherent physiological differences. As this offset is consistent, once centred around the same mean δ13C and Δ13C chronologies from these 3 species can be combined. Δ13C chronologies of the three species demonstrate strong cross-correlations in both high and low frequency fluctuations. Low frequency fluctuations, although consistent between species, show no direct climate relationship, and may be linked with physiological responses to increasing CO2 concentrations. Significant correlations do exist between the high frequency δ13C fluctuations and climate parameters. The high frequency δ13C series of all three species are most significantly correlated with the same two climate parameters and have the same seasonal timing; July October average maximum temperature and June September average relative humidity. Pine δ13C is the most responsive species to climate changes and displays the most significant correlations with all the climate parameters studied. However, an average series of all three high frequency species δ13C series shows the most significant correlations with

  17. Edaphic control of site-related variations in tree-ring nitrogen isotopes in French beech forests

    NASA Astrophysics Data System (ADS)

    Ponton, S.; Dupouey, J.-L.; Weitner, A.; Elhani, S.

    2009-04-01

    Understanding the causes of inter-site variations in wood nitrogen isotopic composition (d15N) is a prerequisite before being able to use this indicator in the time domain, as a bioindicator of past changes in the ecosystem N cycle. Few studies explored the patterns and causes of d15N variations over more than 10 sites. And most of these studies were conducted along very large, continental, transects, where vegetation types and species changed between sites. Here, we study the causes for such inter-sites variations in a network of 75 adult beech (Fagus sylvatica) stands in northeastern France. The sampled sites covered a wide range of edaphic conditions, both in terms of nutrient and water availability, under a homogeneous climate. d15N was measured in pools of 35 rings (6 trees x 7 years) mixed together for each of the 75 sites, after removing the most mobile nitrogen compounds by a short duration extraction. Inter-tree, within site variation was also explored in a subset of 9 sites. Wood inter-site d15N variations were analyzed by statistical comparison with a large set of soil, leaves and stand measurements made in same plots: nutrient and isotopic content (d15N and d13C) of soil and leaves, soil nitrogen potential mineralization and nitrification, soil water availability, stand productivity, vegetation community composition. It appears that wood d15N is a potentially less efficient indicator of site characteristics than leaf d15N because it is more prone to inter-tree (intra-site) variability. Variations in wood d15N correlated very poorly with soil potential mineralization or nitrification. On the other hand, they were significantly related to soil acidity conditions and, more unexpectedly, to water availability. The causes and consequences of these links will be discussed.

  18. Morphological, biochemical and physiological traits of upper and lower canopy leaves of European beech tend to converge with increasing altitude.

    PubMed

    Rajsnerová, Petra; Klem, Karel; Holub, Petr; Novotná, Kateřina; Večeřová, Kristýna; Kozáčiková, Michaela; Rivas-Ubach, Albert; Sardans, Jordi; Marek, Michal V; Peñuelas, Josep; Urban, Otmar

    2015-01-01

    The present work has explored for the first time acclimation of upper versus lower canopy leaves along an altitudinal gradient. We tested the hypothesis that restrictive climatic conditions associated with high altitudes reduce within-canopy variations of leaf traits. The investigated beech (Fagus sylvatica L.) forest is located on the southern slope of the Hrubý Jeseník Mountains (Czech Republic). All measurements were taken on leaves from upper and lower parts of the canopy of mature trees (>85 years old) growing at low (400 m above sea level, a.s.l.), middle (720 m a.s.l.) and high (1100 m a.s.l.) altitudes. Compared with trees at higher altitudes, those growing at low altitudes had lower stomatal conductance, slightly lower CO(2) assimilation rate (A(max)) and leaf mass per area (LMA), and higher photochemical reflectance index, water-use efficiency and Rubisco content. Given similar stand densities at all altitudes, the different growth conditions result in a more open canopy and higher penetration of light into lower canopy with increasing altitude. Even though strong vertical gradients in light intensity occurred across the canopy at all altitudes, lower canopy leaves at high altitudes tended to acquire the same morphological, biochemical and physiological traits as did upper leaves. While elevation had no significant effect on nitrogen (N) and carbon (C) contents per unit leaf area, LMA, or total content of chlorophylls and epidermal flavonoids in upper leaves, these increased significantly in lower leaves at higher altitudes. The increases in N content of lower leaves were coupled with similar changes in A(max). Moreover, a high N content coincided with high Rubisco concentrations in lower but not in upper canopy leaves. Our results show that the limiting role of light in lower parts of the canopy is reduced at high altitudes. A great capacity of trees to adjust the entire canopy is thus demonstrated. PMID:25576757

  19. Floods on Beech River, Wolf and Owl Creeks, Brazil, Onemile and Town Branches; and an unnamed Tributary to Beech River in the vicinity of Lexington, Tennessee

    SciTech Connect

    Not Available

    1985-09-01

    This report describes the extent and severity of the flood potential along selected reaches of the Beech River, Tributary to Beech River, Owl and Wolf Creeks, and Brazil, Onemile and Town Branches in the vicinity of Lexington, Tennessee. The study was requested by the city of Lexington to provided detailed information in order to better administer its floodplain management program.

  20. Fine-root carbon and nitrogen concentration of European beech (Fagus sylvatica L.) in Italy Prealps: possible implications of coppice conversion to high forest

    PubMed Central

    Terzaghi, Mattia; Montagnoli, Antonio; Di Iorio, Antonino; Scippa, Gabriella S.; Chiatante, Donato

    2013-01-01

    Fine-root systems represent a very sensitive plant compartment to environmental changes. Gaining further knowledge about their dynamics would improve soil carbon input understanding. This paper investigates C and N concentrations in fine roots in relation to different stand characteristics resulting from conversion of coppiced forests to high forests. In order to evaluate possible interferences due to different vegetative stages of vegetation, fine-root sampling was repeated six times in each stand during the same 2008 growing season. Fine-root sampling was conducted within three different soil depths (0–10; 10–20; and 20–30 cm). Fine-root traits were measured by means of WinRHIZO software which enable us to separate them into three different diameter classes (0–0.5, 0.5–1.0 and 1.0–2.0 mm). The data collected indicate that N concentration was higher in converted stands than in the coppiced stand whereas C concentration was higher in the coppiced stand than in converted stands. Consequently the fine-root C:N ratio was significantly higher in coppiced than in converted stands and showed an inverse relationship with fine-root turnover rate, confirming a significant change of fine-root status after the conversion of a coppice to high forest. PMID:23785374

  1. Fine-root carbon and nitrogen concentration of European beech (Fagus sylvatica L.) in Italy Prealps: possible implications of coppice conversion to high forest.

    PubMed

    Terzaghi, Mattia; Montagnoli, Antonio; Di Iorio, Antonino; Scippa, Gabriella S; Chiatante, Donato

    2013-01-01

    Fine-root systems represent a very sensitive plant compartment to environmental changes. Gaining further knowledge about their dynamics would improve soil carbon input understanding. This paper investigates C and N concentrations in fine roots in relation to different stand characteristics resulting from conversion of coppiced forests to high forests. In order to evaluate possible interferences due to different vegetative stages of vegetation, fine-root sampling was repeated six times in each stand during the same 2008 growing season. Fine-root sampling was conducted within three different soil depths (0-10; 10-20; and 20-30 cm). Fine-root traits were measured by means of WinRHIZO software which enable us to separate them into three different diameter classes (0-0.5, 0.5-1.0 and 1.0-2.0 mm). The data collected indicate that N concentration was higher in converted stands than in the coppiced stand whereas C concentration was higher in the coppiced stand than in converted stands. Consequently the fine-root C:N ratio was significantly higher in coppiced than in converted stands and showed an inverse relationship with fine-root turnover rate, confirming a significant change of fine-root status after the conversion of a coppice to high forest. PMID:23785374

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    Emberson, Lisa D; Büker, Patrick; Ashmore, Mike R

    2007-06-01

    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. PMID:17412465

  4. Proteomic analysis by two-dimensional differential in gel electrophoresis (2D DIGE) of the early response of Pisum sativum to Orobanche crenata.

    PubMed

    Castillejo, Ma Ángeles; Fernández-Aparicio, Mónica; Rubiales, Diego

    2012-01-01

    Crenate broomrape (Orobanche crenata) is considered to be the major constraint for legume crops in Mediterranean countries. Strategies of control have been developed, but only marginal successes have been achieved. For the efficient control of the parasite, a better understanding of its interaction and associated resistance mechanisms at the molecular level is required. The pea response to this parasitic plant and the molecular basis of the resistance was studied using a proteomic approach based on 2D DIGE and MALDI-MSMS analysis. For this purpose, two genotypes showing different levels of resistance to O. crenata, as well as three time points (21, 25, and 30 d after inoculation) have been compared. Multivariate statistical analysis identified 43 differential protein spots under the experimental conditions (genotypes/treatments), 22 of which were identified using a combination of peptide mass fingerprinting (PMF) and MSMS fragmentation. Most of the proteins identified were metabolic and stress-related proteins and a high percentage of them (86%) matched with specific proteins of legume species. The behaviour pattern of the identified proteins suggests the existence of defence mechanisms operating during the early stages of infection that differed in both genotypes. Among these, several proteins were identified with protease activity which could play an important role in preventing the penetration and connection to the vascular system of the parasite. Our data are discussed and compared with those previously obtained in pea and Medicago truncatula. PMID:21920908

  5. A simple and rapid method to identify and quantitatively analyze triterpenoid saponins in Ardisia crenata using ultrafast liquid chromatography coupled with electrospray ionization quadrupole mass spectrometry.

    PubMed

    Ma, Ling; Li, Wei; Wang, Hanqing; Kuang, Xinzhu; Li, Qin; Wang, Yinghua; Xie, Peng; Koike, Kazuo

    2015-01-01

    Ardisia plant species have been used in traditional medicines, and their bioactive constituents of 13,28-epoxy triterpenoid saponins have excellent biological activities for new drug development. In this study, a fast and simple method based on ultrafast liquid chromatography coupled to electrospray ionization mass spectrometry (UFLC-MS) was developed to simultaneously identify and quantitatively analyze triterpenoid saponins in Ardisia crenata extracts. In total, 22 triterpenoid saponins, including two new compounds, were identified from A. crenata. The method exhibited good linearity, precision and recovery for the quantitative analysis of eight marker saponins. A relative quantitative method was also developed using one major saponin (ardisiacrispin B) as the standard to break through the choke-point of the lack of standards in phytochemical analysis. The method was successfully applied to quantitatively analyze saponins in commercially available plant samples. This study describes the first systematic analysis of 13,28-epoxy-oleanane-type triterpenoid saponins in the genus Ardisia using LC-ESI-MS. The results can provide the chemical support for further biological studies, phytochemotaxonomical studies and quality control of triterpenoid saponins in medicinal plants of the genus Ardisia. PMID:25459939

  6. Carbon assimilation, translocation and respiration in Fagus sylvatica and Abies alba stands measured by gas exchange and isotopic techniques during two contrasting climatic years

    NASA Astrophysics Data System (ADS)

    Gavrichkova, Olga; Scartazza, Andrea; Zampedri, Roberto; Cavagna, Mauro; Sottocornola, Matteo; Matteucci, Giorgio; Brugnoli, Enrico

    2014-05-01

    Global warming is tremendously influencing the climate of mountain areas through constantly rising temperatures and changes in local hydrological cycle. Increase of precipitation extremes, seasonal shifts of rainfall regime, heat waves are becoming more and more frequent events here. Vulnerability and plasticity of the local individual tree species under changing climate has still to be evaluated under field conditions. Two consecutive years, 2012 and 2013 were quite distinct in the climatic conditions during the plant growing season. Summer 2012 was characterized by a prolonged summer drought with almost no precipitation in central Italy from the end of May up to the end of August. The situation was aggravated by a very dry winter during this year. Mean annual temperatures in 2012 were 2oC higher in respect to the temperatures measured in the last 10 years. Conversely, year 2013 was milder with occasional rain events also during the summer months and temperatures close to the average values. In the Alpine zone the difference between two years were less pronounced with 2012 being slightly warmer than average and 2013 was characterized by unusually abundant spring precipitations. Taking advantage of these two contrasting years, we have monitored a functional response of one deciduous and one coniferous mountain forest stands growing in different mountain climate zones to variations in the local climate. The first, a deciduous European beech (Fagus sylvatica) forest, is located in the Appennine region of Italy at 1700 m height (Collelongo site, AQ) and characterized by a Mountain-Mediterranean climate. The second is a mixed forest dominated by Silver fir (Abies alba) which was chosen as a target species for our study. The site is located at 1350m height in the south-eastern Alps (Lavarone, TN) and is characterized by a mountain temperate climate. Sampling of plant material and point flux measurements were performed in the beginning, middle and the end of the growing

  7. Effect on a long-term afforestation of pine in a beech domain in NE-Spain as reflected in soil C and N isotopic signature

    NASA Astrophysics Data System (ADS)

    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

  8. Aggressiveness of Phytophthora cactorum and Phytophthora citricola isolates on European Beech and Lilac

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inoculation experiments were conducted to compare the aggressiveness of Phytophthora cactorum and P. citricola isolates on European beech and lilac seedlings grown in a greenhouse. The isolates were obtained from bleeding cankers on European beech from five cities (Albany, Ithaca, Oyster Bay, P...

  9. Aggressiveness of Phytophthora cactorum, P. citricola I, and P. plurivora from European Beech

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora cactorum and P. citricola cause bleeding cankers on European beech trees in the northeastern United States. Inoculation experiments were conducted to compare the aggressiveness of P. cactorum and P. citricola isolates on stems, leaf disks, and roots of European beech and common lilac s...

  10. Characterization of soil microarthropod communities in Italian beech forest

    NASA Astrophysics Data System (ADS)

    Conti, F. D.; Menta, C.; Piovesan, G.

    2009-04-01

    The contribution of soil organisms to ecosystem functions such as decomposition, nutrient recycling and the maintenance of physico-chemical properties is well recognised, as is the fact that soil fauna plays an important role in the formation and stabilisation of soil structure. The diversity of soil fauna includes a quarter of described living species, the majority of which are insects and arachnids. Soil fauna plays an essential role in forests and agro-ecosystems by maintaining their functionality and productivity. The aim of this study is to evaluate the biodiversity of soil microarthropods communities in different Italian beech forest. Particular attention is paid to the role of fossorial microarthropods in the maintenance of soil structure and in the organic matter movements. Three beech forests are studied, two located in the North and one in the Centre of Italy. Microarthropods are extracted from litter and soil with a Berlese-Tullgren funnel, identified to order level (class level for myriapods) and counted using a microscope. Relative order abundance and biodiversity are expressed using the Shannon-Weaver diversity index (H) and evenness index (J). Soil biological quality is expressed using the QBS-ar index and Acari/Collembola ratio. The results show a richness of microarthropods: several orders, till 19 different groups, are determined and identified. Acari and collembola are the main represented taxa and, especially in litter samples, pseudoscorpions, different specimens of diplopods (or millipedes) and chilopods (centipedes) are found. Thus the presence in particular of diplopods offers the possibility of studying fossorial microarthropods functions in detail. Furthermore, both in soil and in litter samples, adapted groups are recognized, such as pauropods, symphyla, proturans and diplurans, with specific morphological characteristics that these species suited to soil habitat. Therefore they attest a good level of soil quality and high natural value

  11. Variation in Pollen-Donor Composition among Pollinators in an Entomophilous Tree Species, Castanea crenata, Revealed by Single-Pollen Genotyping

    PubMed Central

    Hasegawa, Yoichi; Suyama, Yoshihisa; Seiwa, Kenji

    2015-01-01

    Background In plants, reproductive success is largely determined by the composition of pollen (i.e., self-pollen and outcross-pollen from near and distant pollen-donors) transported as a result of pollinator foraging behavior (e.g., pollen carryover). However, little evidence is available on how and to what extent the pollen carryover affects the pollen-donor composition and on which insect taxa are effective outcross-pollen transporters under field conditions. In this study, we explored roles of foraging behavior of insect pollinators on pollen-donor composition and subsequent reproductive success in a woody plant. Methods We performed paternity analyses based on microsatellite genotyping of individual pollen grains found on diurnal pollinators (i.e., bumblebee, small bee, fly, small beetle, and honeybee) visiting Castanea crenata trees. Results The outcross-pollen rate was highest in bumblebees (66%), followed by small bees (35%), flies (31%), and small beetles (18%). The effective number of pollen donors, representing pollen carryover, was greater in bumblebees (9.71) than in flies (3.40), small bees (3.32), and small beetles (3.06). The high percentages of pollen from outside the plot on bumblebees (65.4%) and flies (71.2%) compared to small bees (35.3%) and small beetles (13.5%) demonstrated their longer pollen dispersal distances. Conclusions All of the diurnal insects carried outcross-pollen grains for long distances via pollen carryover. This fact suggests that a wide range of insect taxa are potential outcross-pollen transporters for the self-incompatible C. crenata. PMID:25793619

  12. Quantifying genetic variations and phenotypic plasticity of leaf phenology and growth for two temperate Fagaceae species (sessile oak and european beech)

    NASA Astrophysics Data System (ADS)

    Delzon, Sylvain; Vitasse, Yann; Alberto, Florian; Bresson, Caroline; Kremer, Antoine

    2010-05-01

    Under current climate change, research on inherent adaptive capacities of organisms is crucial to assess future evolutionary changes of natural populations. Genetic diversity and phenotypic plasticity constitute adaptative capacities that could allow populations to respond to new environmental conditions. The aim of the present study was (i) to determine whether there are genetic variations among populations from altitudinal gradients using a lowland common garden experiment and (ii) to assess the magnitude of phenotypic plasticity using a reciprocal transplant experiment (5 elevations from 100 to 1600 m asl.) for leaf phenology (flushing and senescence) and growth of two fagaceae species (Fagus sylvatica and Quercus petraea). We found significant differences in phenology among provenances for most species, and evidenced that these among-population differences in phenology were related to annual temperature of the provenance sites for both species. It's noteworthy that, along the same climatic gradient, the species exhibited opposite genetic clines: beech populations from high elevation flushed earlier than those of low elevation, whereas we observed an opposite trend for oak. Finally, we highlighted that both phenology timing and growth rate were highly consistent year to year. The results demonstrated that in spite of the proximity of the populations in their natural area, altitude led to genetic differentiations in their phenology and growth. Moreover, a high phenological plasticity was found for both species. We evidenced that reaction norms of flushing timing to temperature followed linear clinal trends for both species with an average shift of 5.7 days per degree increase. Timing of leaf senescence exhibited hyperbolic trends for beech and no or slight trends for oak. Furthermore, within species, there was no difference in magnitude of phenological plasticity among populations neither for flushing, nor for senescence. Consequently, for both species, the

  13. Co-occurrence patterns of trees along macro-climatic gradients and their potential influence on the present and future distribution of Fagus sylvatica L.

    USGS Publications Warehouse

    Meier, E.S.; Edwards, T.C., Jr.; Kienast, Felix; Dobbertin, M.; Zimmermann, N.E.

    2011-01-01

    Aim During recent and future climate change, shifts in large-scale species ranges are expected due to the hypothesized major role of climatic factors in regulating species distributions. The stress-gradient hypothesis suggests that biotic interactions may act as major constraints on species distributions under more favourable growing conditions, while climatic constraints may dominate under unfavourable conditions. We tested this hypothesis for one focal tree species having three major competitors using broad-scale environmental data. We evaluated the variation of species co-occurrence patterns in climate space and estimated the influence of these patterns on the distribution of the focal species for current and projected future climates.Location Europe.Methods We used ICP Forest Level 1 data as well as climatic, topographic and edaphic variables. First, correlations between the relative abundance of European beech (Fagus sylvatica) and three major competitor species (Picea abies, Pinus sylvestris and Quercus robur) were analysed in environmental space, and then projected to geographic space. Second, a sensitivity analysis was performed using generalized additive models (GAM) to evaluate where and how much the predicted F. sylvatica distribution varied under current and future climates if potential competitor species were included or excluded. We evaluated if these areas coincide with current species co-occurrence patterns.Results Correlation analyses supported the stress-gradient hypothesis: towards favourable growing conditions of F. sylvatica, its abundance was strongly linked to the abundance of its competitors, while this link weakened towards unfavourable growing conditions, with stronger correlations in the south and at low elevations than in the north and at high elevations. The sensitivity analysis showed a potential spatial segregation of species with changing climate and a pronounced shift of zones where co-occurrence patterns may play a major role

  14. Visualizing carbon and nitrogen transfer in the tripartite symbiosis of Fagus sylvatica, ectomycorrhizal fungi and soil microorganisms using NanoSIMS

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    Translocation of recently photoassimilated plant carbon (C) into soil via root exudates or mycorrhizal fungi is key to understand global carbon cycling. Plants support symbiotic fungi and soil microorganisms with recent photosynthates to get access to essential elements, such as nitrogen (N) and phosphorus. While a 'reciprocal reward strategy' (plants trade C in exchange for nutrients from the fungus) has been shown for certain types of mycorrhizal associations, only little is known about the mechanisms of C and N exchange between mycorrhizal fungal hyphae and soil bacteria. Our understanding of the underlying mechanisms is hampered by the fact that C and N transfer between plants, mycorrhizal fungi and soil bacteria takes place at the micrometer scale, which makes it difficult to explore at the macro scale. In this project we intended to analyse carbon and nitrogen flows between roots of beech trees (Fagus sylvatica), their associated ectomycorrhizal fungi and bacterial community. In order to visualize this nutrient flow at a single cell level, we used a stable isotope double labelling (13C and 15N) approach. Young mycorrhizal beech trees were transferred from a forest to split-root boxes, consisting of two compartments separated by a membrane (35 μm mesh size) which was penetrable for hyphae but not for plant roots. After trees and mycorrhizal fungi were allowed to grow for one year in these boxes, 15N-labelled nitrogen solution was added only to the root-free compartment to allow labelled nitrogen supply only through the fungal network. 13C- labelled carbon was applied by exposing the plants to a 13CO2 gas atmosphere for 8 hours. Spatial distribution of the isotopic label was visualised at the microscale in cross sections of mycorrhizal root-tips (the plant/mycorrhizal fungi interface) and within and on the surface of external mycorrhizal hyphae (the fungi/soil bacteria interface) using nanoscale secondary ion mass spectrometry (NanoSIMS). Corresponding

  15. Long-term growth trajectories in a changing climate: disentangling age from size effects in old Fagus trees from contrasting bioclimates

    NASA Astrophysics Data System (ADS)

    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

  16. Combining stable isotope and carbohydrate analyses in phloem sap and fine roots to study seasonal changes of source-sink relationships in a Mediterranean beech forest.

    PubMed

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

    2015-08-01

    Carbon isotope composition (δ(13)C) and carbohydrate content of phloem sap and fine roots were measured in a Mediterranean beech (Fagus sylvatica L.) forest throughout the growing season to study seasonal changes of source-sink relationships. Seasonal variations of δ(13)C and content of phloem sap sugars, collected during the daylight period, reflected the changes in soil and plant water status. The correlation between δ(13)C and content of phloem sap sugars, collected from plants belonging to different social classes, was significantly positive only during the driest month of July. In this month, δ(13)C of phloem sap sugars was inversely related to the increment of trunk radial growth and positively related to δ(13)C of fine roots. We conclude that the relationship between δ(13)C and the amount of phloem sap sugars is affected by a combination of causes, such as sink strength, tree social class, changes in phloem anatomy and transport capacity, and phloem loading of sugars to restore sieve tube turgor following the reduced plant water potential under drought conditions. However, δ(13)C and sugar composition of fine roots suggested that phloem transport of leaf sucrose to this belowground component was not impaired by mild drought and that sucrose was in a large part allocated towards fine roots in July, depending on tree social class. Hence, fine roots could represent a functional carbon sink during the dry seasonal periods, when transport and use of assimilates in other sink tissues are reduced. These results indicate a strict link between above- and belowground processes and highlight a rapid response of this Mediterranean forest to changes in environmental drivers to regulate source-sink relationships and carbon sink capacity. PMID:26093372

  17. Estimation of beech pyrolysis kinetic parameters by Shuffled Complex Evolution.

    PubMed

    Ding, Yanming; Wang, Changjian; Chaos, Marcos; Chen, Ruiyu; Lu, Shouxiang

    2016-01-01

    The pyrolysis kinetics of a typical biomass energy feedstock, beech, was investigated based on thermogravimetric analysis over a wide heating rate range from 5K/min to 80K/min. A three-component (corresponding to hemicellulose, cellulose and lignin) parallel decomposition reaction scheme was applied to describe the experimental data. The resulting kinetic reaction model was coupled to an evolutionary optimization algorithm (Shuffled Complex Evolution, SCE) to obtain model parameters. To the authors' knowledge, this is the first study in which SCE has been used in the context of thermogravimetry. The kinetic parameters were simultaneously optimized against data for 10, 20 and 60K/min heating rates, providing excellent fits to experimental data. Furthermore, it was shown that the optimized parameters were applicable to heating rates (5 and 80K/min) beyond those used to generate them. Finally, the predicted results based on optimized parameters were contrasted with those based on the literature. PMID:26551654

  18. Rainfall interception by an evergreen beech forest, Nelson, New Zealand

    NASA Astrophysics Data System (ADS)

    Rowe, L. K.

    1983-10-01

    Throughfall under a beech ( Nothofagus) forest canopy at Donald Creek, Nelson, averaged 69% of the rain falling on the canopy, i.e. 1060 mm of 1530 mm in a year of normal rainfall. Using an estimate for stemflow at 2% of gross rainfall, interception loss averaged 29% of the annual rainfall, or 440 mm yr. -1. Seasonal differences in interception loss were significant, ranging from 22% in winter to 35% in summer, and resulted from seasonal variation in evaporation rates from a wet canopy. Seasonal variation in rainfall rate was slight. Four models, storm linear regression, monthly linear regression, sine curve and Gash's analytical model, were tested by comparison of predicted and observed interception. All gave very satisfactory estimates (< 10% error) and tended to slightly underestimate the measured interception loss.

  19. Comparing the intra-annual wood formation of three European species (Fagus sylvatica, Quercus petraea and Pinus sylvestris) as related to leaf phenology and non-structural carbohydrate dynamics.

    PubMed

    Michelot, Alice; Simard, Sonia; Rathgeber, Cyrille; Dufrêne, Eric; Damesin, Claire

    2012-08-01

    Monitoring cambial phenology and intra-annual growth dynamics is a useful approach for characterizing the tree growth response to climate change. However, there have been few reports concerning intra-annual wood formation in lowland temperate forests with high time resolution, especially for the comparison between deciduous and coniferous species. The main objective of this study was to determine how the timing, duration and rate of radial growth change between species as related to leaf phenology and the dynamics of non-structural carbohydrates (NSC) under the same climatic conditions. We studied two deciduous species, Fagus sylvatica L. and Quercus petraea (Matt.) Liebl., and an evergreen conifer, Pinus sylvestris L. During the 2009 growing season, we weekly monitored (i) the stem radial increment using dendrometers, (ii) the xylem growth using microcoring and (iii) the leaf phenology from direct observations of the tree crowns. The NSC content was also measured in the eight last rings of the stem cores in April, June and August 2009. The leaf phenology, NSC storage and intra-annual growth were clearly different between species, highlighting their contrasting carbon allocation. Beech growth began just after budburst, with a maximal growth rate when the leaves were mature and variations in the NSC content were low. Thus, beech radial growth seemed highly dependent on leaf photosynthesis. For oak, earlywood quickly developed before budburst, which probably led to the starch decrease quantified in the stem from April to June. For pine, growth began before the needles unfolding and the lack of NSC decrease during the growing season suggested that the substrates for radial growth were new assimilates of the needles from the previous year. Only for oak, the pattern determined from the intra-annual growth measured using microcoring differed from the pattern determined from dendrometer data. For all species, the ring width was significantly influenced by growth duration

  20. Gross nitrogen fluxes in intact beech-soil-microbe systems under experimentally simulated climate change

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    The vulnerability of beech forests of Central Europe to projected climate change conditions is a current matter of debate and concern. In order to investigate the response of N cycling in a typical beech forest to projected climate change conditions, we transplanted small lysimeters with intact beech-soil systems from a slope with N-exposure (representing present day climate conditions) to a slope with S exposure (serving as a warmer and drier model climate for future conditions). Lysimeters transfers within the N exposure served as control. After an equilibration period of 1 year, three isotope labeling/harvest cycles were performed: (1) comparison between N and S slopes under ambient conditions; (2) comparison between N and S slopes after intensified drought at S exposure; (3) rewetting after the drought period. Homogenous triple isotope labeling (15N/13C glutamine, 15NH4+, 15NO3-) in combination with 15N tracing and -pool dilution approaches as well as molecular analyses of nitrogen cycling genes and mycorrhiza morphotyping allowed to simultaneously quantify all N turnover processes in the intact beech-soil-microbe system. Nitrate was the major N source of beech seedlings with little importance of ammonium and no importance of glutamine. Experimental simulation of climate change resulted in significantly reduced gene copies of ammonia oxidizing bacteria in soil (AOB), a dramatic attenuation of microbial gross nitrate production from 252±83 mg N m-2 day-1 for the control treatment to 49±29 mg N m-2 day-1 for the climate change treatment and associated strong declines in soil nitrate concentrations as well as nitrate uptake by microorganisms and beech, which could not be compensated by uptake of ammonium or glutamine. Therefore, N content of beech seedlings was strongly reduced in the climate change treatment. Hence our data provide a microbial mechanism to explain nutritional limitations of beech under higher temperatures and drought and raise questions about

  1. Frequency of inversions affects senescence phenology of Acer pseudoplatanus and Fagus sylvatica

    NASA Astrophysics Data System (ADS)

    Schuster, Christina; Kirchner, Manfred; Jakobi, Gert; Menzel, Annette

    2014-05-01

    In mountainous regions, inversion situations with cold-air pools in the valleys occur frequently, especially in fall and winter. With the accumulation of inversion days, trees in lower elevations experience lower temperature sums than those in middle elevations. In a two-year observational study, deciduous trees, such as Acer pseudoplatanus and Fagus sylvatica, on altitudinal transects responded in their fall leaf senescence phenology. Phenological phases were advanced and senescence duration was shortened by the cold temperatures in the valley. This effect was more distinct for late phases than for early phases since they experienced more inversion days. The higher the inversion frequency, the stronger the signal was. Acer pseudoplatanus proved to be more sensitive to cold temperatures compared to Fagus sylvatica. We conclude that cold-air pools have a considerable impact on the vegetation period of deciduous trees. Considering this effect, trees in the mid hillside slopes gain advantages compared to lower elevations. Our findings will help to improve knowledge about ecological drivers and responses in mountainous forest ecosystems.

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

    PubMed Central

    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

  3. Fast wood decay in a mountain Mediterranean area having Fagus sylvatica forests

    NASA Astrophysics Data System (ADS)

    Fravolini, Giulia; Egli, Markus; Cherubini, Paolo; Tognetti, Roberto; Lombardi, Fabio; Marchetti, Marco

    2015-04-01

    Deadwood and litter act as important linkages between recent productivity and current community, and ecosystem processes. The increasing interest in the quantity and properties of coarse woody debris (CWD) and litter is relevant both to maintaining biodiversity and to global C dynamics. Mountain and Mediterranean areas, furthermore, are considered to be especially sensitive to changing environmental conditions. Consequently, a need exists to understand more in detail the interplay between soils, forests, deadwood and climate in general and in particular in mountain Mediterranean areas such as the Appenine. Due to the fact that linkages between climate, coarse woody decay and soils in mountain Mediterranean areas are only poorly understood, we aimed at investigating the decay mechanism of Fagus silvatica as a function of altitude and exposure. Furthermore, the effects of exposure on the decay dynamics of dead wood and soils were compared along a altitudinal sequence in an Appenine mountain forest (Majella Mountain). Ten sites, five of which having north and the other 5 having south exposure, were investigated, ranging from 1000 m to 1650 m asl. All sites have a Fagus sylvatica forest. In addition to this, experimental plots were installed at each site. In May 2014 standardised wood blocks (5 x 5 x 2 cm) of local Fagus sylvatica were placed at each site inside PVC tubes ('mesocosms') that was filled with undisturbed soil material. The sampling design foresees that three replicates of such mesocosms per site will be sampled after 8 , 16, 52 and 104 weeks. After 8 weeks three tubes were removed from the sites (sampled soil and dead wood blocks) and the wood blocks analysed for cellulose, lignin and density. At each site, three cores were taken to analyse soil properties. The soil cores were subdivided in 0 - 5, 5 - 10 and 10 - 15 cm depth and measured for organic carbon, carbonates and pH. In addition, the humus forms at each site were determined. Already after 8 weeks

  4. Topical application of a cleanser containing extracts of Diospyros kaki folium, Polygonum cuspidatum and Castanea crenata var. dulcis reduces skin oil content and pore size in human skin

    PubMed Central

    LEE, BO MI; AN, SUNGKWAN; KIM, SOO-YEON; HAN, HYUN JOO; JEONG, YU-JIN; LEE, KYOUNG-ROK; ROH, NAM KYUNG; AHN, KYU JOONG; AN, IN-SOOK; CHA, HWA JUN

    2015-01-01

    The effects of skin pores on skin topographic features can be reduced by decreasing excessive production and accumulation of sebum and elimination of comedones. Therefore, a cosmetic cleanser that regulates sebum homeostasis is required. In the present study, the effects of a cosmetic cleanser that contained Diospyros kaki folium, Polygonum cuspidatum and Castanea crenata var. dulcis (DPC) was examined on the removal of sebum and on skin pore size. Healthy volunteers (n=23) aged 20–50 years were asked to apply the test materials to the face. Skin oil content, pore size, pore number and extracted sebum surface area were measured using various measurement methods. All the measurements were performed at pre- and post-application of the test materials. When the cosmetic cleanser containing DPC was applied to the skin, the oil content decreased by 77.3%, from 6.19 to 1.40. The number of skin pores decreased by 24.83%, from 125.39 to 94.23. Skin pore size decreased from 0.07 to 0.02 µm3 (71.43% decrease). The amount of extracted sebum increased by 335% when the DPC cleanser was used. Compared to the control cleanser, skin oil content was significantly decreased when the cleanser that contained DPC was used. The cleanser containing DPC also decreased pore size and number. Finally, the DPC cleanser easily removed solidified sebum from the skin. PMID:26137233

  5. Ardisia crenata extract stimulates melanogenesis in B16F10 melanoma cells through inhibiting ERK1/2 and Akt activation.

    PubMed

    Yao, Cheng; Jin, Cheng Long; Oh, Jang-Hee; Oh, Inn Gyung; Park, Chi-Hyun; Chung, Jin Ho

    2015-01-01

    Melanin protects the skin against ultraviolet radiation by scattering incoming light and absorbing diverse free radicals. Agents that increase melanin synthesis in melanocytes may reduce the risk of photodamage and skin cancer. The present study investigated the effect of a methanol extract of Ardisia crenata (AC) on melanogenesis in B16F10 cells. Treatment of cultured B16F10 cells with AC extract (10, 20 and 40 µg/ml) stimulated an increase in melanin levels in a concentration-dependent manner, without cytotoxicity. Tyrosinase is key in the regulation of melanin production, thus the effect of AC extract on tyrosinase activity and protein expression was analyzed. AC extract was observed to significantly increase tyrosinase activity and protein expression in B16F10 cells. Furthermore, AC extract was found to markedly increase the protein expression of microphthalmia-associated transcription factor, which is an important transcription factor involved in tyrosinase gene expression. In addition, AC extract (40 µg/ml) was observed to suppress the activation of extracellular signal-regulated kinase (ERK) and Akt, which negatively regulate melanin synthesis in B16F10 cells. In conclusion, to the best of our knowledge, the present study is the first to show that a methanol extract of AC stimulates melanogenesis by increasing tyrosinase expression via the inhibition of ERK and Akt. Thus, methanol extract of AC may be a potential treatment for hypopigmentation diseases and may be a candidate for skin-tanning cosmetic products. PMID:25333888

  6. Novel ssDNA virus recovered from estuarine Mollusc (Amphibola crenata) whose replication associated protein (Rep) shares similarities with Rep-like sequences of bacterial origin.

    PubMed

    Dayaram, Anisha; Goldstien, Sharyn; Zawar-Reza, Peyman; Gomez, Christopher; Harding, Jon S; Varsani, Arvind

    2013-05-01

    Over the past couple of years highly diverse novel ssDNA viruses have been discovered. Here, we present the first ssDNA virus, Gastropod-associated circular ssDNA virus (GaCSV), recovered from a mollusc Amphibola crenata Martyn 1784, which is a deposit feeder that grazes micro-organisms and organic detritus on the surface of tidal mudflats. The GaCSV (2351 nt) genome contains two large bidirectionally transcribed ORFs. The smaller ORF (874 nt) has similarities to viral replication-associated protein (Rep) sequences of some bacteria and circoviruses, whereas the larger ORF (955 nt) does not relate to any sequences in public databases and we presume it potentially encodes the capsid protein. Phylogenetic analysis shows that the GaCSV Rep clusters with Rep-like sequences of bacterial origin, highlighting the role of ssDNA viruses in horizontal gene transfer. The occurrence of previously unknown viruses in organisms associated with human pollution is a relatively unexplored field. PMID:23364192

  7. Exclusive accumulation of Z-isomers of monolignols and their glucosides in bark of Fagus grandifolia

    NASA Technical Reports Server (NTRS)

    Lewis, N. G.; Inciong, E. J.; Ohashi, H.; Towers, G. H.; Yamamoto, E.

    1988-01-01

    In addition to Z-coniferyl and Z-sinapyl alcohols, bark extracts of Fagus grandifolia also contain significant amounts of the glucosides, Z-coniferin, Z-isoconiferin (previously called faguside) and Z-syringin. The corresponding E-isomers of these glucosides do not accumulate to a detectable level. The accumulation of the Z-isomers suggests that either they are not lignin precursors or that they are reservoirs of monolignols for subsequent lignin biosynthesis; it is not possible to distinguish between these alternatives. The co-occurrence of Z-coniferin and Z-isoconiferin demonstrate that glucosylation of monolignols can occur at either the phenolic or the allylic hydroxyl groups.

  8. Fault-related fluid flow, Beech Mountain thrust sheet, Blue Ridge Province, Tennessee-North Carolina

    SciTech Connect

    Waggoner, W.K.; Mora, C.I. . Dept. of Geological Sciences)

    1992-01-01

    The latest proterozoic Beech Granite is contained within the Beech Mountain thrust sheet (BMTS), part of a middle-late Paleozoic thrust complex located between Mountain City and Grandfather Mountain windows in the western Blue Ridge of TN-NC. At the base of the BMTS, Beech Granite is juxtaposed against lower Paleozoic carbonate and elastics of the Rome Fm. along the Stone Mountain thrust on the southeaster margin of the Mountain City window. At the top of the BMTS, Beech Granite occurs adjacent to Precambrian mafic rocks of the Pumpkin Patch thrust sheet (PPTS). The Beech Granite is foliated throughout the BMTS with mylonitization and localized cataclasis occurring within thrust zones along the upper and lower margins of the BMTS. Although the degree of mylonitization and cataclasis increases towards the thrusts, blocks of relatively undeformed granite also occur within these fault zones. Mylonites and thrusts are recognized as conduits for fluid movement, but the origin of the fluids and magnitude and effects of fluid migration are not well constrained. This study was undertaken to characterize fluid-rock interaction within the Beech Granite and BMTS. Extensive mobility of some elements/compounds within the thrust zones, and the isotopic and mineralogical differences between the thrust zones and interior of the BMTS indicate that fluid flow was focused within the thrust zones. The wide range of elevated temperatures (400--710 C) indicated by qz-fsp fractionations suggest isotopic disequilibrium. Using a more likely temperature range of 300--400 C for Alleghanian deformation, calculated fluid compositions indicate interactions with a mixture of meteoric-hydrothermal and metamorphic water with delta O-18 = 2.6--7.5[per thousand] for the upper thrust zone and 1.3 to 6.2[per thousand] for the lower thrust zone. These ranges are similar to isotopic data reported for other Blue Ridge thrusts and may represent later periods of meteoric water influx.

  9. Insect attraction to herbivore-induced beech volatiles under different forest management regimes.

    PubMed

    Gossner, Martin M; Weisser, Wolfgang W; Gershenzon, Jonathan; Unsicker, Sybille B

    2014-10-01

    Insect herbivore enemies such as parasitoids and predators are important in controlling herbivore pests. From agricultural systems we know that land-use intensification can negatively impact biological control as an important ecosystem service. The aim of our study was to investigate the importance of management regime for natural enemy pressure and biological control possibilities in forests dominated by European beech. We hypothesize that the volatile blend released from herbivore-infested beech trees functions as a signal, attracting parasitoids and herbivore enemies. Furthermore, we hypothesize that forest management regime influences the composition of species attracted by these herbivore-induced beech volatiles. We installed flight-interception traps next to Lymantria dispar caterpillar-infested young beech trees releasing herbivore-induced volatiles and next to non-infested control trees. Significantly more parasitoids were captured next to caterpillar-infested trees compared to non-infested controls, irrespective of forest type. However, the composition of the trophic guilds in the traps did vary in response to forest management regime. While the proportion of chewing insects was highest in non-managed forests, the proportion of sucking insects peaked in forests with low management and of parasitoids in young, highly managed, forest stands. Neither the number of naturally occurring beech saplings nor herbivory levels in the proximity of our experiment affected the abundance and diversity of parasitoids caught. Our data show that herbivore-induced beech volatiles attract herbivore enemies under field conditions. They further suggest that differences in the structural complexity of forests as a consequence of management regime only play a minor role in parasitoid activity and thus in indirect tree defense. PMID:25080178

  10. A pyrosequencing insight into sprawling bacterial diversity and community dynamics in decaying deadwood logs of Fagus sylvatica and Picea abies

    PubMed Central

    Hoppe, Björn; Krger, Krüger; Kahl, Tiemo; Arnstadt, Tobias; Buscot, François; Bauhus, Jürgen; Wubet, Tesfaye

    2015-01-01

    Deadwood is an important biodiversity hotspot in forest ecosystems. While saproxylic insects and wood-inhabiting fungi have been studied extensively, little is known about deadwood-inhabiting bacteria. The study we present is among the first to compare bacterial diversity and community structure of deadwood under field conditions. We therefore compared deadwood logs of two temperate forest tree species Fagus sylvatica and Picea abies using 16S rDNA pyrosequencing to identify changes in bacterial diversity and community structure at different stages of decay in forest plots under different management regimes. Alphaproteobacteria, Acidobacteria and Actinobacteria were the dominant taxonomic groups in both tree species. There were no differences in bacterial OTU richness between deadwood of Fagus sylvatica and Picea abies. Bacteria from the order Rhizobiales became more abundant during the intermediate and advanced stages of decay, accounting for up to 25% of the entire bacterial community in such logs. The most dominant OTU was taxonomically assigned to the genus Methylovirgula, which was recently described in a woodblock experiment of Fagus sylvatica. Besides tree species we were able to demonstrate that deadwood physico-chemical properties, in particular remaining mass, relative wood moisture, pH, and C/N ratio serve as drivers of community composition of deadwood-inhabiting bacteria. PMID:25851097

  11. A pyrosequencing insight into sprawling bacterial diversity and community dynamics in decaying deadwood logs of Fagus sylvatica and Picea abies.

    PubMed

    Hoppe, Björn; Krger, Krüger; Kahl, Tiemo; Arnstadt, Tobias; Buscot, François; Bauhus, Jürgen; Wubet, Tesfaye

    2015-01-01

    Deadwood is an important biodiversity hotspot in forest ecosystems. While saproxylic insects and wood-inhabiting fungi have been studied extensively, little is known about deadwood-inhabiting bacteria. The study we present is among the first to compare bacterial diversity and community structure of deadwood under field conditions. We therefore compared deadwood logs of two temperate forest tree species Fagus sylvatica and Picea abies using 16S rDNA pyrosequencing to identify changes in bacterial diversity and community structure at different stages of decay in forest plots under different management regimes. Alphaproteobacteria, Acidobacteria and Actinobacteria were the dominant taxonomic groups in both tree species. There were no differences in bacterial OTU richness between deadwood of Fagus sylvatica and Picea abies. Bacteria from the order Rhizobiales became more abundant during the intermediate and advanced stages of decay, accounting for up to 25% of the entire bacterial community in such logs. The most dominant OTU was taxonomically assigned to the genus Methylovirgula, which was recently described in a woodblock experiment of Fagus sylvatica. Besides tree species we were able to demonstrate that deadwood physico-chemical properties, in particular remaining mass, relative wood moisture, pH, and C/N ratio serve as drivers of community composition of deadwood-inhabiting bacteria. PMID:25851097

  12. Two Lactarius species associated with a relict Fagus grandifolia var. mexicana population in a Mexican montane cloud forest.

    PubMed

    Montoya, L; Haug, I; Bandala, V M

    2010-01-01

    Ectomycorrhizal (EM) fleshy fungi are being monitored in a population of Fagus grandifolia var. mexicana persisting in a montane cloud forest refuge on a volcano in a subtropical region of central Veracruz (eastern Mexico). The population of Fagus studied represents one of the 10 recognized forest fragments still housing this tree genus in Mexico. This is the first attempt to document EM fungi associated with this tree species in Mexico. We present evidence of the ectomycorrhizal symbiosis for Lactarius badiopallescens and L. cinereus with this endemic tree. Species identification of Lactarius on Fagus grandifolia var. mexicana was based on the comparison of DNAsequences (ITS rDNA) of spatiotemporally co-occurring basidiomes and EM root tips. The host of the EM tips was identified by comparison of the large subunit of the ribulose-bisphosphate carboxylase gene (rbcL). The occurrence of Lactarius badiopallescens and L. cinereus populations in the area of study represent the southernmost record known to date of these two species in North America and are new for the Neotropical Lactarius mycota. Descriptions coupled with illustrations of macro- and micromorphological features of basidiomes as well as photographs of ectomycorrhizas are presented. PMID:20120238

  13. Branch enclosure BVOC flux measurements from Fagus sylvatica L. in a natural forest environment: preliminary results

    NASA Astrophysics Data System (ADS)

    Demarcke, M.; Amelynck, C.; Schoon, N.; Müller, J.-F.; Joo, E.; Dewulf, J.; van Langenhove, H.; Šimpraga, M.; Steppe, K.; Lemeur, R.; Samson, R.

    2009-04-01

    Natural ecosystems, such as forests, are known to be important sources of non-methane volatile organic compounds (NMVOCs). Oxidation of these biogenic VOCs (BVOCs) in the presence of nitrogen oxides can result in net ozone formation and the low-volatility oxidation products may contribute to secondary organic aerosol formation and/or growth. As a result BVOC emissions can have a negative effect on air quality and human health. In the commonly used emission algorithms [Guenther et al., 1995], leaf temperature and photosynthetic photon flux density (PPFD) are the driving variables for BVOC emissions. However, in order to better explain the variability over time of BVOC emissions for a given tree species, the most recent emission algorithms, such as MEGAN [Guenther et al., 2006], also consider other driving variables such as phenology, temperature and light history. To validate these new emission algorithms, dynamic branch enclosure BVOC flux measurements have been performed on an adult Fagus sylvatica L. tree in a natural forest environment under ambient PPFD and temperature conditions. Branches at different levels in the canopy were accessible from a 35 m high measurement tower. The cuvette air was analysed on-line with a hs-PTR-MS instrument, which was located in a log cabin at the bottom of the tower. Ion signals related to monoterpenoid compounds (m/z 81 and 137), isoprene (m/z 69), acetone (m/z 59) and methanol (m/z 33) have been measured continuously with the PTR-MS during several phenological periods, from bud-break to senescence. The data show high monoterpenoid emission rates in spring which gradually decrease until leaf fall. Furthermore, monoterpenoid emissions from shaded leaves in the lower layers of the canopy were found to be negligible compared to those from sunlit leaves in the upper layer of the canopy. Effects of light and temperature history on monoterpenoid emissions from Fagus sylvatica L. will be discussed and compared with results obtained in

  14. Stability and control derivative estimates obtained from flight data for the Beech 99 aircraft

    NASA Technical Reports Server (NTRS)

    Tanner, R. R.; Montgomery, T. D.

    1979-01-01

    Lateral-directional and longitudinal stability and control derivatives were determined from flight data by using a maximum likelihood estimator for the Beech 99 airplane. Data were obtained with the aircraft in the cruise configuration and with one-third flap deflection. The estimated derivatives show good agreement with the predictions of the manufacturer.

  15. Tree ring isotopes of beech and spruce in response to short-term climate variability across Central European sites: Common and contrasting physiological mechanisms

    NASA Astrophysics Data System (ADS)

    Weigt, Rosemarie; Klesse, Stefan; Treydte, Kerstin; Frank, David; Saurer, Matthias; Siegwolf, Rolf T. W.

    2016-04-01

    The combined study of tree-ring width and stable C and O isotopes provides insight in the coherences between carbon allocation during stem growth and the preceding conditions of gas exchange and formation of photosynthates as all influenced by environmental variation. In this large-scale study comprising 10 sites across a range of climate gradients (temperature, precipitation) throughout Central Europe, we investigated tree-rings in European beech (Fagus sylvatica) and Norway spruce (Picea abies) trees. The sampling design included larger and smaller trees. The short-term, i.e. year-to-year, variability in the isotope time series over 100 yrs was analyzed in relation to tree-ring growth and climate variation. The generally strong correlation between the year-to-year differences in δ13C (corrected for the atmospheric shift due to 13C-depleted CO2 from fossil combustion) and δ18O across most sites emphasized the role of stomatal conductance in controlling leaf gas exchange. However, the correlation between both isotopes decreased during some periods. At several sites this reduction in correlation was particularly pronounced during recent decades. This suggests a decoupling between stomatal and photosynthetic responses to environmental conditions on the one hand, and carbon allocation to stem tissue on the other hand. Variability in the isotopic ratio largely responded to summer climate, but was weakly correlated to annual stem growth. In contrast, climate sensitivity of radial growth in both species was rather site-dependent, and was strongest at the driest (in terms of soil water capacity) site. We will also present results of isotope responses with respect to extreme climate events. Understanding the underlying physiological mechanisms controlling the short-term variation in tree-ring signals will help to assess and more precisely constrain the possible range of growth performance of these ecologically and economically important tree species under future climate

  16. Canopy transpiration of pure and mixed forest stands with variable abundance of European beech

    NASA Astrophysics Data System (ADS)

    Gebauer, Tobias; Horna, Viviana; Leuschner, Christoph

    2012-06-01

    SummaryThe importance of tree species identity and diversity for biogeochemical cycles in forests is not well understood. In the past, forestry has widely converted mixed forests to pure stands while contemporary forest policy often prefers mixed stands again. However, the hydrological consequences of these changes remain unclear. We tested the hypotheses (i) that significant differences in water use per ground area exist among the tree species of temperate mixed forests and that these differences are more relevant for the amount of stand-level canopy transpiration (Ec) than putative complementarity effects of tree water use, and (ii) that the seasonal patterns of Ec in mixed stands are significantly influenced by the identity of the present tree species. We measured xylem sap flux during 2005 (average precipitation) and 2006 (relatively dry) synchronously in three nearby old-growth forest stands on similar soil differing in the abundance of European beech (pure beech stand, 3-species stand with 70% beech, 5-species stand with <10% beech). In summer 2005 with average rainfall, Ec was 50% higher in the beech-poor 5-species stand than in the two stands with moderate to high beech presence (158 vs. 97 and 101 mm yr-1); in the dry summer 2006, all stands converged toward similar Ec totals (128-139 mm yr-1). Species differences in Ec were large on a sapwood area basis, reflecting a considerable variation in hydraulic architecture and leaf conductance regulation among the co-existing species. Moreover, transpiration per crown projection area (ECA) also differed up to 5-fold among the different species in the mixed stands, probably reflecting contrasting sapwood/crown area ratios. We conclude that Ec is not principally higher in mixed forests than in pure beech stands. However, tree species-specific traits have an important influence on the height of Ec and affect its seasonal variation. Species with a relatively high ECA (notably Tilia) may exhaust soil water reserves

  17. Beech vs. Pine - how different tree species manage their water demands

    NASA Astrophysics Data System (ADS)

    Heidbüchel, Ingo; Dreibrodt, Janek; Simard, Sonia; Güntner, Andreas; Blume, Theresa

    2016-04-01

    In north-eastern Germany large parts of the landscape are covered by pine trees. Although beech used to be one of the typical species for the region, today it makes up only a small fraction of the forested area. In order to reinstate a more natural forest composition an effort is made to decrease the coniferous forest in the next 30 years from 70% to 40% while increasing the deciduous forest from 20% to 40%. This will have consequences for the forest water balance that we would like to understand better. In an attempt to capture the complete tree water balance for both species we monitored all relevant hydrologic fluxes in four stands of pure beech and pine (both young and old stands) as well as in eight mixed stands (as part of the TERENO observatory). Extensive measurements of throughfall and stemflow were conducted with 35 rain trough systems, 50 stemflow collectors and tipping buckets. Soil moisture was monitored in 70 depth profiles with a total of 450 sensors ranging from 10 cm down to 200 cm. In combination with soil water potential measurements at 5 depths root water uptake from different depths and hydraulic redistribution between depths could be determined. Sapflux sensors recorded tree water use for 16 trees and groundwater level was monitored at 16 locations. We found that soil moisture conditions under beech were more variable than under pine, especially in the upper 100 cm. This was due to the higher influx of water from stemflow on the one hand and to the more intensive/effective use of soil water by the beech on the other hand. Our sap flux measurements show that beech was able to sustain steady rates of sapflux even under extremely dry soil conditions. While annual average sapflow was twice as high for pines compared to beeches, pine trees were less effective in taking up water from the soil and reduced sap flow considerably during dry phases. We still found the upper 100 cm of soil under pine to be generally wetter than under beech and considered

  18. Fluxes of CO2, CH4 and N2O at two European beech forests: linking soil gas production profiles with soil and stem fluxes

    NASA Astrophysics Data System (ADS)

    Maier, Martin; Machacova, Katerina; Halaburt, Ellen; Haddad, Sally; Urban, Otmar; Lang, Friederike

    2016-04-01

    consumption sites of soil gases in the adjacent soil. Soils at both sites took up CH4 and N2O and emitted CO2. Soil gas profiles at the Black Forest showed only CH4 and N2O consumption. CH4 uptake was much larger by the well aerated Black Forest soil than by the loamy-clay soil in the White Carpathians. Here, it was possible to stratify the apparently homogenous site into two plots, one having redoximorphic features in the soil profiles, the other plot without. It seemed that CH4 and N2O were mainly produced in the deeper soil at the plot with temporarily reducing conditions. Beech stems mostly took up N2O from the atmosphere at both sites, whereas CH4 was emitted. The stem CH4 flux was higher for the White Carpathians than for the Black Forest site. Thus, the tree and soil flux of CH4 seems to be affected by soil structure, soil water content and the redox potential in the rooting space. We conclude from our results that trees might provide preferential pathways for greenhouse gases produced in the subsoil thereby enhancing the release of greenhouse gases. Acknowledgement This 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 for technical support and Sinikka Paulus for help by field measurements.

  19. Variation in biogenic volatile organic compound emission pattern of Fagus sylvatica L. due to aphid infection

    NASA Astrophysics Data System (ADS)

    Joó, É.; Van Langenhove, H.; Šimpraga, M.; Steppe, K.; Amelynck, C.; Schoon, N.; Müller, J.-F.; Dewulf, J.

    2010-01-01

    Volatile organic compounds (VOCs) have been the focus of interest to understand atmospheric processes and their consequences in formation of ozone or aerosol particles; therefore, VOCs contribute to climate change. In this study, biogenic VOCs (BVOCs) emitted from Fagus sylvatica L. trees were measured in a dynamic enclosure system. In total 18 compounds were identified: 11 monoterpenes (MT), an oxygenated MT, a homoterpene (C 14H 18), 3 sesquiterpenes (SQT), isoprene and methyl salicylate. The frequency distribution of the compounds was tested to determine a relation with the presence of the aphid Phyllaphis fagi L. It was found that linalool, (E)-β-ocimene, α-farnesene and a homoterpene identified as (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), were present in significantly more samples when infection was present on the trees. The observed emission spectrum from F. sylvatica L. shifted from MT to linalool, α-farnesene, (E)-β-ocimene and DMNT due to the aphid infection. Sabinene was quantitatively the most prevalent compound in both, non-infected and infected samples. In the presence of aphids α-farnesene and linalool became the second and third most important BVOC emitted. According to our investigation, the emission fingerprint is expected to be more complex than commonly presumed.

  20. Short-term natural δ13C variations in pools and fluxes in a beech forest: the transfer of isotopic signal from recent photosynthates to soil respired CO2

    NASA Astrophysics Data System (ADS)

    Gavrichkova, O.; Proietti, S.; Moscatello, S.; Portarena, S.; Battistelli, A.; Matteucci, G.; Brugnoli, E.

    2011-03-01

    The fate of photosynthetic products within the plant-soil continuum determines how long the reduced carbon resides within the ecosystem and when it returns back to the atmosphere in the form of respiratory CO2. We have tested the possibility of measuring natural variation in δ13C to disentangle potential times needed to transfer carbohydrates produced by photosynthesis down to roots and, in general, to belowground up to its further release in the form of soil respiration into the atmosphere in a beech (Fagus sylvatica) forest. For these purposes we have measured the variation in stable carbon and oxygen isotope compositions in plant material and in soil respired CO2 every three hours for three consequent days. Possible steps and different signs of post-photosynthetic fractionation during carbon translocation were also identified. A 12 h-periodicity was observed for variation in δ13C in soluble sugars in the top crown leaves and it can be explained by starch day/night dynamics in synthesis and breakdown and by stomatal limitations under elevated vapour pressure deficits. Photosynthetic products were transported down the trunk and mixed with older carbon pools, therefore causing the dampening of the δ13C signal variation. The strongest periodicity of 24 h was found in δ13C in soil respiration indicating changes in root contribution to the total CO2 efflux. Nevertheless, it was possible to identify the speed of carbon translocation through the plant-soil continuum. A period of 24 h was needed to transfer the C assimilated by photosynthesis from the top crown leaves to the tree trunk at breast height and additional 3 h for further respiration of that C by roots and soil microorganisms and its to subsequent diffusion back to the atmosphere.

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

    PubMed Central

    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. PMID:26859755

  2. Experimental assessment on the frost sensitivity during leaf development of juvenile Fagus sylvatica L.

    NASA Astrophysics Data System (ADS)

    Estrella, Nicole; Menzel, Annette

    2014-05-01

    Late frost events in spring shape species distribution as well as reduce productivity. Till now, it is still not clear if future warming will lead to more frequent / stronger / more harmful frost damages in forestry and agriculture or not. Since the variability of extremes is increasing it seems that the risk of late frost damages in many regions may not decrease, even if the mean air temperature in general is increasing. A late frost event is only harmful if plants have initiated their leaf / flower development. Closed buds are usually very frost tolerant. However, once leaves develop after mild and warm spring periods, the new tissue is especially sensitive to freezing temperatures. Therefore not only the date of the last frost but also the weather history of the late winter / early spring determines if a frost event might result in frost damage or not. Tissue sensitivity to frost varies among species, but even within species there might be differences in frost tolerance during the different stages in leaf development. We set up an experiment to identify the frost risk in connection with the developmental stage of the leaves of juvenile beech. In order to vary the timing of frost events, we placed 1-year old potted beech trees 7times overnight in a climate chamber, in which the air temperature was cooled down to - 3° for five hours. For each tree the phenological stages were observed before and after the frost, the percent of damage was estimated after two days; additionally phenology of the damaged plants was observed weekly to document the recovery of their damage till May 23, 2013. Only about 30% of the plants were damaged. In general it can be stated if damage occurred it was a severe damage, only very few plants sustained little damage. We observed dependence on the date of the freezing event, rather than on specific phenological phases - the later the frost was applied the more plants were damaged. Damaged plants recovered relatively rapidly from the frost

  3. Comparative estimates of transpiration of ash and beech forest at a chalk site in southern Britain

    NASA Astrophysics Data System (ADS)

    Roberts, John; Rosier, Paul T. W.

    1994-11-01

    (1) During the dry summer of 1989 stomatal conductance ( gs), boundary-layer conductance ( ga), leaf water and osmotic potentials ( ψ1, ψπ) and leaf area index ( L∗) measurements were made in mature ash and beech stands growing on shallow soil over chalk near Winchester, Hampshire, UK. In addition measurements of gs and L∗ were made in the understorey layer in the ash stand, comprised mainly of dog's mercury, hazel and bramble. Automatic weather stations located (i) above the beech stand and (ii) at the understorey level (within the ash stand) provided hourly averages of weather variables. Changes in soil moisture deficit in both stands were determined from regular measurements made with a neutron probe. (2) Maximum values of gs (up to 0.3 mol m -2 s -1) were found at the top of the ash and beech canopies at the start of the day, while at the canopy base gs was about half of these values. At all canopy levels the value of gs was more closely associated with specific humidity deficit (at the time of measurement) than with any other weather variable, and there was no relationship between gs and soil mositure deficit or leaf water status, described by ψ1 and ψπ on the day of measurement. (3) Values of gs of the understorey plants were only half those of the tree species and changed less during the day. However, seasonal changes in gs of dog's mercury did seem to be associated with increased soil moisture deficit. (4) Estimates of L∗ in the ash and beech stands were made from leaf litter collections and partitioned into canopy layers using ratios determined by destructive sampling. L∗ of the beech stand was 5.3 and for the ash stand 2.7. L∗ of the understorey varied seasonally and rose to a peak of 3 in June falling gradually for the remainder of the summer period. (5) Hourly values of gs and ga in each stand for each canopy layer were scaled up to the canopy by using L∗ of the individual canopy layers (including the understorey level in the ash stand

  4. Carbon isotope discrimination during branch photosynthesis of Fagus sylvatica: field measurements using laser spectrometry.

    PubMed

    Gentsch, Lydia; Sturm, Patrick; Hammerle, Albin; Siegwolf, Rolf; Wingate, Lisa; Ogée, Jérôme; Baur, Thomas; Plüss, Peter; Barthel, Matti; Buchmann, Nina; Knohl, Alexander

    2014-04-01

    On-line measurements of photosynthetic carbon isotope discrimination ((13)Δ) under field conditions are sparse. Hence, experimental verification of the natural variability of instantaneous (13)Δ is scarce, although (13)Δ is, explicitly and implicitly, used from leaf to global scales for inferring photosynthetic characteristics. This work presents the first on-line field measurements of (13)Δ of Fagus sylvatica branches, at hourly resolution, using three open branch bags and a laser spectrometer for CO₂ isotopologue measurements (QCLAS-ISO). Data from two August/September field campaigns, in 2009 and 2010, in a temperate forest in Switzerland are shown. Diurnal variability of (13)Δ was substantial, with mean diurnal amplitudes of ~9‰ and maximum diurnal amplitudes of ~20‰. The highest (13)Δ were generally observed during early morning and late afternoon, and the lowest (13)Δ during midday. An assessment of propagated standard deviations of (13)Δ demonstrated that the observed diurnal variation of (13)Δ was not a measurement artefact. Day-to-day variations of (13)Δ were summarized with flux-weighted daily means of (13)Δ, which ranged from 15‰ to 23‰ in 2009 and from 18‰ to 29‰ in 2010, thus displaying a considerable range of 8-11‰. Generally, (13)Δ showed the expected negative relationship with intrinsic water use efficiency. Diurnal and day-to-day variability of (13)Δ was, however, always better predicted by that of net CO₂ assimilation, especially in 2010 when soil moisture was high and vapour pressure deficit was low. Stomatal control of leaf gas exchange, and consequently (13)Δ, could only be identified under drier conditions in 2009. PMID:24676031

  5. Anti-ice nucleation activity in xylem extracts from trees that contain deep supercooling xylem parenchyma cells.

    PubMed

    Kasuga, Jun; Mizuno, Kaoru; Arakawa, Keita; Fujikawa, Seizo

    2007-12-01

    Boreal hardwood species, including Japanese white birch (Betula platyphylla Sukat. var. japonica Hara), Japanese chestnut (Castanea crenata Sieb. et Zucc.), katsura tree (Cercidiphyllum japonicum Sieb. et Zucc.), Siebold's beech (Fagus crenata Blume), mulberry (Morus bombycis Koidz.), and Japanese rowan (Sorbus commixta Hedl.), had xylem parenchyma cells (XPCs) that adapt to subfreezing temperatures by deep supercooling. Crude extracts from xylem in all these trees were found to have anti-ice nucleation activity that promoted supercooling capability of water as measured by a droplet freezing assay. The magnitude of increase in supercooling capability of water droplets in the presence of ice-nucleation bacteria, Erwinia ananas, was higher in the ranges from 0.1 to 1.7 degrees C on addition of crude xylem extracts than freezing temperature of water droplets on addition of glucose in the same concentration (100 mosmol/kg). Crude xylem extracts from C. japonicum provided the highest supercooling capability of water droplets. Our additional examination showed that crude xylem extracts from C. japonicum exhibited anti-ice nucleation activity toward water droplets containing a variety of heterogeneous ice nucleators, including ice-nucleation bacteria, not only E. ananas but also Pseudomonas syringae (NBRC3310) or Xanthomonas campestris, silver iodide or airborne impurities. However, crude xylem extracts from C. japonicum did not affect homogeneous ice nucleation temperature as analyzed by emulsified micro-water droplets. The possible role of such anti-ice nucleation activity in crude xylem extracts in deep supercooling of XPCs is discussed. PMID:17936742

  6. Skin blood flow in psoriasis during Goeckerman or beech tar therapy.

    PubMed

    Staberg, B; Klemp, P

    1984-01-01

    Skin blood flow (SBF) was measured by the laser Doppler technique in lesional and clinically normal skin of 8 patients with psoriasis vulgaris during Goeckerman or beech tar therapy. The SBF measurements were performed before therapy and 1, 2, and 3-4 weeks after treatment was initiated. The results were compared to a clinical psoriasis index based on the objective assessment of infiltration, erythema, and scaling of the psoriatic plaques. The pre-treatment value of SBF in lesional skin was about 9 times higher than that of clinically normal skin. During therapy SBF of involved skin decreased rapidly approaching that of uninvolved skin after 3-4 weeks. Furthermore, there was a significant linear correlation between the SBF values and the clinical psoriasis index. It is concluded that SBF in psoriatic lesions decreases significantly during Goeckerman or beech tar therapy, and that this variable might be used to obtain a quantitative measure of the disease activity. PMID:6209892

  7. Differences in carbon uptake and water use between managed and unmanaged European beech forests

    NASA Astrophysics Data System (ADS)

    Herbst, M.; Mund, M.; Knohl, A.

    2013-12-01

    Based on 23 site-years of eddy covariance measurements made above a managed beech forest and a nearby unmanaged, old-growth forest in central Germany, a comparative analysis of the carbon and energy fluxes of the two forests was carried out. Both forests are located at similar altitude and they face similar meteorological conditions. They are also similar with respect to canopy height (37 m) and mean tree age (120 years). The managed beech forest is a monospecific, even-aged stand with species-rich ground vegetation and a leaf area index of about 4, whereas the old-growth forest is beech-dominated but interspersed with ash and sycamore trees. It has a multi-layer canopy consisting of trees of various ages ranging from 0 to 260 years and its leaf area index is about 5. On average the two forests did not differ significantly in annual net carbon uptake (508 and 483 g C m-2 a-1 for the managed and the unmanaged forest, respectively), however the managed forest showed a much larger interannual variability in gross primary production than the unmanaged forest did. This trend agreed well with independent dendrometric measurements made in both forests. In contrast, ecosystem respiration did neither vary significantly between the two forests nor between different years. The total annual evapotranspiration was slightly higher at the unmanaged forest site (549 mm a-1 compared to 504 mm a-1 at the managed site), which was probably due to a higher interception loss from the denser canopy in the unmanaged forest. We discuss whether the conclusion can be drawn from this case study that common forest management activities improve the water use efficiency of European beech forests but make them more vulnerable against extreme meteorological conditions such as, for example, summer heat waves or late frosts in spring.

  8. Climate change reverses the competitive balance of ash and beech seedlings under simulated forest conditions.

    PubMed

    Saxe, H; Kerstiens, G

    2005-07-01

    This study identifies the important role of climate change and photosynthetic photon flux density (PPFD) in the regenerative competence of ash and beech seedlings in 12 inter- and intra-specific competition designs in simulated mixed ash-beech forest gaps under conditions of non-limiting soil volume, water and nutrient supply. The growth conditions simulated natural forest conditions as closely as possible. Simulations were performed by growing interacting seedling canopies for one season in temperature-regulated closed-top chambers (CTCs). Eight CTCs were used in a factorial design with replicate treatments of [CO2] x temperature x PPFD x competition design. [CO2] tracked ambient levels or was 360 micromol mol-1 higher. Temperature tracked ambient levels or was 2.8 degrees C higher. PPFD on two plant tables inside each CTC was 16% and 5% of open-field levels, respectively, representative of typical light flux levels in a natural forest gap. In several of the competition designs, climate change made the ash seedlings grow taller than the beech seedlings and, at the same time, attain a larger leaf area and a larger total biomass. Advantages of this type for ash were found particularly at lower PPFD. There was a positive synergistic interaction of elevated temperature x [CO2] for both species, but more so for ash. There are many uncertainties when a study of chambered seedlings is to be projected to real changes in natural forests. Nevertheless, this study supports a possible future shift towards ash in north European, unmanaged, mixed ash-beech forests in response to the predicted climate change. PMID:16025410

  9. Beech Fructification and Bank Vole Population Dynamics - Combined Analyses of Promoters of Human Puumala Virus Infections in Germany

    PubMed Central

    Reil, Daniela; Imholt, Christian; Eccard, Jana Anja; Jacob, Jens

    2015-01-01

    The transmission of wildlife zoonoses to humans depends, amongst others, on complex interactions of host population ecology and pathogen dynamics within host populations. In Europe, the Puumala virus (PUUV) causes nephropathia epidemica in humans. In this study we investigated complex interrelations within the epidemic system of PUUV and its rodent host, the bank vole (Myodes glareolus). We suggest that beech fructification and bank vole abundance are both decisive factors affecting human PUUV infections. While rodent host dynamics are expected to be directly linked to human PUUV infections, beech fructification is a rather indirect predictor by serving as food source for PUUV rodent hosts. Furthermore, we examined the dependence of bank vole abundance on beech fructification. We analysed a 12-year (2001-2012) time series of the parameters: beech fructification (as food resource for the PUUV host), bank vole abundance and human incidences from 7 Federal States of Germany. For the first time, we could show the direct interrelation between these three parameters involved in human PUUV epidemics and we were able to demonstrate on a large scale that human PUUV infections are highly correlated with bank vole abundance in the present year, as well as beech fructification in the previous year. By using beech fructification and bank vole abundance as predictors in one model we significantly improved the degree of explanation of human PUUV incidence. Federal State was included as random factor because human PUUV incidence varies considerably among states. Surprisingly, the effect of rodent abundance on human PUUV infections is less strong compared to the indirect effect of beech fructification. Our findings are useful to facilitate the development of predictive models for host population dynamics and the related PUUV infection risk for humans and can be used for plant protection and human health protection purposes. PMID:26214509

  10. Responses of beech and spruce foliage to elevated carbon dioxide, increased nitrogen deposition and soil type.

    PubMed

    Günthardt-Goerg, Madeleine Silvia; Vollenweider, Pierre

    2015-01-01

    Although enhanced carbon fixation by forest trees may contribute significantly to mitigating an increase in atmospheric carbon dioxide (CO2), capacities for this vary greatly among different tree species and locations. This study compared reactions in the foliage of a deciduous and a coniferous tree species (important central European trees, beech and spruce) to an elevated supply of CO2 and evaluated the importance of the soil type and increased nitrogen deposition on foliar nutrient concentrations and cellular stress reactions. During a period of 4 years, beech (represented by trees from four different regions) and spruce saplings (eight regions), planted together on either acidic or calcareous forest soil in the experimental model ecosystem chambers, were exposed to single and combined treatments consisting of elevated carbon dioxide (+CO2, 590 versus 374 μL L(-1)) and elevated wet nitrogen deposition (+ND, 50 versus 5 kg ha(-1) a(-1)). Leaf size and foliage mass of spruce were increased by +CO2 on both soil types, but those of beech by +ND on the calcareous soil only. The magnitude of the effects varied among the tree origins in both species. Moreover, the concentration of secondary compounds (proanthocyanidins) and the leaf mass per area, as a consequence of cell wall thickening, were also increased and formed important carbon sinks within the foliage. Although the species elemental concentrations differed in their response to CO2 fertilization, the +CO2 treatment effect was weakened by an acceleration of cell senescence in both species, as shown by a decrease in photosynthetic pigment and nitrogen concentration, discolouration and stress symptoms at the cell level; the latter were stronger in beech than spruce. Hence, young trees belonging to a species with different ecological niches can show contrasting responses in their foliage size, but similar responses at the cell level, upon exposure to elevated levels of CO2. The soil type and its nutrient supply

  11. Responses of beech and spruce foliage to elevated carbon dioxide, increased nitrogen deposition and soil type

    PubMed Central

    Günthardt-Goerg, Madeleine Silvia; Vollenweider, Pierre

    2015-01-01

    Although enhanced carbon fixation by forest trees may contribute significantly to mitigating an increase in atmospheric carbon dioxide (CO2), capacities for this vary greatly among different tree species and locations. This study compared reactions in the foliage of a deciduous and a coniferous tree species (important central European trees, beech and spruce) to an elevated supply of CO2 and evaluated the importance of the soil type and increased nitrogen deposition on foliar nutrient concentrations and cellular stress reactions. During a period of 4 years, beech (represented by trees from four different regions) and spruce saplings (eight regions), planted together on either acidic or calcareous forest soil in the experimental model ecosystem chambers, were exposed to single and combined treatments consisting of elevated carbon dioxide (+CO2, 590 versus 374 μL L−1) and elevated wet nitrogen deposition (+ND, 50 versus 5 kg ha−1 a−1). Leaf size and foliage mass of spruce were increased by +CO2 on both soil types, but those of beech by +ND on the calcareous soil only. The magnitude of the effects varied among the tree origins in both species. Moreover, the concentration of secondary compounds (proanthocyanidins) and the leaf mass per area, as a consequence of cell wall thickening, were also increased and formed important carbon sinks within the foliage. Although the species elemental concentrations differed in their response to CO2 fertilization, the +CO2 treatment effect was weakened by an acceleration of cell senescence in both species, as shown by a decrease in photosynthetic pigment and nitrogen concentration, discolouration and stress symptoms at the cell level; the latter were stronger in beech than spruce. Hence, young trees belonging to a species with different ecological niches can show contrasting responses in their foliage size, but similar responses at the cell level, upon exposure to elevated levels of CO2. The soil type and its nutrient supply

  12. Interactive effects of juvenile defoliation, light conditions, and interspecific competition on growth and ectomycorrhizal colonization of Fagus sylvatica and Pinus sylvestris seedlings.

    PubMed

    Trocha, Lidia K; Weiser, Ewa; Robakowski, Piotr

    2016-01-01

    Seedlings of forest tree species are exposed to a number of abiotic (organ loss or damage, light shortage) and biotic (interspecific competition) stress factors, which may lead to an inhibition of growth and reproduction and, eventually, to plant death. Growth of the host and its mycorrhizal symbiont is often closely linked, and hence, host damage may negatively affect the symbiont. We designed a pot experiment to study the response of light-demanding Pinus sylvestris and shade-tolerant Fagus sylvatica seedlings to a set of abiotic and biotic stresses and subsequent effects on ectomycorrhizal (ECM) root tip colonization, seedling biomass, and leaf nitrogen content. The light regime had a more pronounced effect on ECM colonization than did juvenile damage. The interspecific competition resulted in higher ECM root tip abundance for Pinus, but this effect was insignificant in Fagus. Low light and interspecific competition resulted in lower seedling biomass compared to high light, and the effect of the latter was partially masked by high light. Leaf nitrogen responded differently in Fagus and Pinus when they grew in interspecific competition. Our results indicated that for both light-demanding (Pinus) and shade-tolerant (Fagus) species, the light environment was a major factor affecting seedling growth and ECM root tip abundance. The light conditions favorable for the growth of seedlings may to some extent compensate for the harmful effects of juvenile organ loss or damage and interspecific competition. PMID:26003665

  13. Unraveling the growth determinism of Fagus sylvatica: a hybrid data-model approach

    NASA Astrophysics Data System (ADS)

    Guillemot, Joannès; Martin-StPaul, Nicolas; Delpierre, Nicolas; François, Christophe; Soudani, Kamel; Restoux, Gwendal; Dufrêne, Eric

    2013-04-01

    The physiological processes underlying the limitation of forest growth are still under debate. Growth has long been considered as a carbone (C) limited process (Sala et al., 2012). As a matter of facts, a recent global meta-analysis has shown good agreements between assimilated C and forest productivity (Litton et al., 2007). Consequently, a majority of the process-based productivity models considers growth as a fraction of the net primary production (NPP) (Lacointe et al., 2000; Sitch et al., 2003. However, investigations at the stand scale report conflicting results (Rocha et al., 2006, Mund et al., 2010) and are not systematically consistent with a strict C limitation of growth, thus challenging the C-centric paradigm. The mechanisms that potentially degrade the link between NPP and growth include: i) the direct effect of environmental factors on growth (Zweifel et al., 2006, Körner et al., 2003), ii) the temporal variability of the growth allocation coefficient, due either to ontogeny (Genet et al., 2009), or to the initial physiological state of the tree i.e. to the reaction to past conditions. Indeed, many dendrochronological and ecological studies have shown a correlation between growth and climatic factors of the previous years (e.g. Lebourgeois et al., 2005; Richardson et al., 2012). In this work, we used a hybrid data model approach in order to assess the determinant of Fagus sylvatica stem growth along a spatial gradient across France. Despite they could brought essential insight on tree functioning, intra-specific studies across contrasted sites are still lacking in the current debate. Standardized annual growth data series at the stand scale were calculated using circumference inventories and dendrochronological series on 17 plots of the RENECOFOR network. We used the process-based model CASTANEA, thoroughly validated in long term flux simulation across Europe (e.g. Delpierre et al. 2009), to simulate the annual NPP of the corresponding periods. We

  14. Flight test evaluation of a separate surface attitude command control system on a Beech 99 airplane

    NASA Technical Reports Server (NTRS)

    Gee, S. W.; Jenks, G. E.; Roskam, J.; Stone, R. L.

    1976-01-01

    A joint NASA/university/industry program was conducted to flight evaluate a potentially low cost separate surface implementation of attitude command in a Beech 99 airplane. Saturation of the separate surfaces was the primary cause of many problems during development. Six experienced professional pilots who made simulated instrument flight evaluations experienced improvements in airplane handling qualities in the presence of turbulence and a reduction in pilot workload. For ride quality, quantitative data show that the attitude command control system results in all cases of airplane motion being removed from the uncomfortable ride region.

  15. Flight test evaluation of a separate surface attitude command control system on a Beech 99 airplane

    NASA Technical Reports Server (NTRS)

    Gee, S. W.; Jenks, G. E.; Roskam, J.; Stone, R. L.

    1976-01-01

    A joint NASA/university/industry program was conducted to flight evaluate a potentially low cost separate surface implementation of attitude command in a Beech 99 airplane. Saturation of the separate surfaces was the primary cause of many problems during development. Six experienced professional pilots made simulated instrument flight evaluations in light-to-moderate turbulence. They were favorably impressed with the system, particularly with the elimination of control force transients that accompanied configuration changes. For ride quality, quantitative data showed that the attitude command control system resulted in all cases of airplane motion being removed from the uncomfortable ride region.

  16. Comparative economic and environmental assessment of four beech wood based biorefinery concepts.

    PubMed

    Budzinski, Maik; Nitzsche, Roy

    2016-09-01

    The aim of this study was to analyze four conceptual beech wood based biorefineries generated during process design in terms of environmental and economic criteria. Biorefinery 1 annually converts 400,000 dry metric tons of beech wood into the primary products 41,600t/yr polymer-grade ethylene and 58,520tDM/yr organosolv lignin and the fuels 90,800tDM/yr hydrolysis lignin and 38,400t/yr biomethane. Biorefinery 2 is extended by the product of 58,400t/yr liquid "food-grade" carbon dioxide. Biorefinery 3 produces 69,600t/yr anhydrous ethanol instead of ethylene. Compared to biorefinery 3, biorefinery 4 additionally provides carbon dioxide as product. Biorefinery 3 and 4 seem most promising, since under basic assumptions both criteria, (i) economic effectiveness and (ii) reduction of potential environmental impacts, can be fulfilled. All four alternatives may reduce potential environmental impacts compared to reference systems using the ReCiPe methodology. Economic feasibilities of the analyzed biorefineries are highly sensitive. PMID:27285577

  17. Carabid beetle diversity and mean individual biomass in beech forests of various ages.

    PubMed

    Jelaska, Lucija Šerić; Dumbović, Vlatka; Kučinić, Mladen

    2011-01-01

    Carabid beetle diversity and mean individual biomass (MIB) were analysed in three different successional stages of beech tree stands (60, 80 and 150 years old). Carabid beetles were captured using pitfall traps placed at nine sites (three per age class) in the Papuk Mountain of East Croatia during 2008. A cluster analysis identified three groupings that corresponded to the beech age classes. MIB values increased with stand age, ranging from 255 in 60-year-old stand to 537 in the oldest forests. The 80-year-old stand showed the highest species richness and diversity values. With respect to species composition, large species such as Carabus scheidleri and Carabus coriaceus were dominant only in the oldest forests. Furthermore, species that overwinter in the larval stage were more abundant in the oldest forests (45% of the total number of individuals from the 150-year-old stand) than in the younger ones (20% of individuals from 60-year-old, and 22% of individuals from 80-year-old stands). Our results showed that the analyses of species composition and life history traits are valuable for estimating the conservation values of older forests. Although the investigated sites form part of a continuous forested area and are only a couple of kilometres apart, MIB values detect significant differences associated with forest age and can be a useful tool in evaluating the degree to which a forest reflects a natural state. PMID:21738423

  18. Late Glacial beech forest: an 18,000 5000-BP pollen record from Auckland, New Zealand

    NASA Astrophysics Data System (ADS)

    Lancashire, A. K.; Flenley, J. R.; Harper, M.

    2002-07-01

    Australia, New Zealand and South America are the main sources of terrestrial climate change records for midlatitudes in the Southern Hemisphere. The advantage of studying the New Zealand record is that its vegetation has been subject to human influence for only the last thousand years. Vegetation records for Auckland are important because earlier work indicates that during the Last Glacial Maximum, the boundary between scrubland and forest lay in the Auckland region. Auckland is situated in a volcanic field and the coring site was in the crater of a small extinct volcano (Crater Hill, formed about 29 ka BP). The 4-m long core contained sediment dating from c. 5 to c. 18 ka BP. We present pollen and diatom records from this core. The pollen records from basal clays indicate southern beech forest (mainly Nothofagus menziesii) was present in the region around Crater Hill from 18 to 14.5 ka BP. At this time, there were areas of scrub in the crater surrounding a hardwater lake. The southern forest limit could well have been close to the site. Records from overlying peat indicate beech forest was replaced by Podocarp broadleaf forest as the Last Glacial ended. Metrosideros spp. (coastal forest trees) peak in the early Holocene. This coincides with an impoverished diatom flora which indicates drier conditions in the basin. When the lake reformed in the Holocene on peat its water was more acidic.

  19. The influece of forest gaps on some properties of humus in a managed beech forest, northern Iran

    NASA Astrophysics Data System (ADS)

    Vajari, K. A.

    2015-10-01

    The present research focuses on the effect of eight-year-old artificially created gaps on some properties of humus in managed beech-dominated stand in Hyrcanian forest of northern Iran. In this study, six-teen gaps were sampled in site and were classified into four classes (small, medium, large, and very large) with four replications for each. Humus sampling was carried out at the centre and at the cardinal points within each gap as well as in the adjacent closed stand, separately, as composite samples. The variables of organic carbon, P, K, pH, and total N were measured for each sample. It was found that the gap size had significant effect only on total N (%) and organic carbon (%) in beech stand. The amount of potassium clearly differed among three positions in beech forest. The adjacent stand had higher significantly potassium than center and edge of gaps. Different amount of potassium was detected in gap center and gap edge. Comparison of humus properties between gaps and its adjacent stand pointed to the higher amount of potassium in adjacent stand than that in gaps but there was no difference between them regarding other humus properties. According to the results, it can be concluded that there is relatively similar condition among gaps and closed adjacent stands in terms of humus properties eight years after logging in the beech stand.

  20. Short-term natural δ13C and δ18O variations in pools and fluxes in a beech forest: the transfer of isotopic signal from recent photosynthates to soil respired CO2

    NASA Astrophysics Data System (ADS)

    Gavrichkova, O.; Proietti, S.; Moscatello, S.; Portarena, S.; Battistelli, A.; Matteucci, G.; Brugnoli, E.

    2011-10-01

    The fate of photosynthetic products within the plant-soil continuum determines how long the reduced carbon resides within the ecosystem and when it returns back to the atmosphere in the form of respiratory CO2. We have tested the possibility of measuring natural variation in δ13C and δ18O to disentangle the potential times needed to transfer carbohydrates produced by photosynthesis down to trunk, roots and, in general, to belowground up to its further release in the form of soil respiration into the atmosphere in a beech (Fagus sylvatica) forest. We have measured the variation in stable carbon and oxygen isotope compositions in plant material and in soil respired CO2 every three hours for three consecutive days. Possible steps and different signs of post-photosynthetic fractionation during carbon translocation were also identified. A 12 h-periodicity was observed for variation in δ13C in soluble sugars in the top crown leaves and it can be explained by starch day/night dynamics in synthesis and breakdown and by stomatal limitations under elevated vapour pressure deficits. Photosynthetic products were transported down the trunk and mixed with older carbon pools, therefore causing the dampening of the δ13C signal variation. The strongest periodicity of 24 h was found in δ13C in soil respiration indicating changes in root contribution to the total CO2 efflux. Other non-biological causes like diffusion fractionation and advection induced by gas withdrawn from the measurement chamber complicate data interpretation on this step of C transfer path. Nevertheless, it was possible to identify the speed of carbohydrates' translocation from the point of assimilation to the trunk breast height because leaf-imprinted enrichment of δ18O in soluble sugars was less modified along the downward transport and was well related to environmental parameters potentially linked to stomatal conductance. The speed of carbohydrates translocation from the site of assimilation to the trunk

  1. Climate change impairs processes of soil and plant N cycling in European beech forests on marginal soil

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Beech forests of Central Europe are covering large areas with marginal calcareous soils, but provide important ecological services and represent a significant economical value. The vulnerability of these ecosystems to projected climate conditions (higher temperatures, increase of extreme drought and precipitation events) is currently unclear. Here we present comprehensive data on the influence of climate change conditions on ecosystem performance, considering soil nitrogen biogeochemistry, soil microbiology, mycorrhiza ecology and plant physiology. We simultaneously quantified major plant and soil gross N turnover processes by homogenous triple 15N isotope labeling of intact beech natural regeneration-soil-microbe systems. This isotope approach was combined with a space for time climate change experiment, i.e. we transferred intact beech seedling-soil-microbe mesocosms from a slope with N-exposure (representing present day climate conditions) to a slope with S exposure (serving as a warmer and drier model climate for future conditions). Transfers within N slope served as controls. After an equilibration period of 1 year, three isotope labeling/harvest cycles were performed. Reduced soil water content resulted in a persistent decline of ammonia oxidizing bacteria in soil (AOB). Consequently, we found a massive five-fold reduction of gross nitrification in the climate change treatment and a subsequent strong decline in soil nitrate concentrations as well as nitrate uptake by microorganisms and beech. Because nitrate was the major nutrient for beech in this forest type with little importance of ammonium and amino acids, this resulted in a strongly reduced performance of beech natural regeneration with reduced N content, N metabolite concentrations and plant biomass. These findings provided an explanation for a large-scale decline of distribution of beech forests on calcareous soils in Europe by almost 80% until 2080 predicted by statistical modeling. Hence, we

  2. Impact of elevated CO2 concentration on dynamics of leaf photosynthesis in Fagus sylvatica is modulated by sky conditions.

    PubMed

    Urban, Otmar; Klem, Karel; Holišová, Petra; Šigut, Ladislav; Šprtová, Mirka; Teslová-Navrátilová, Petra; Zitová, Martina; Špunda, Vladimír; Marek, Michal V; Grace, John

    2014-02-01

    It has been suggested that atmospheric CO2 concentration and frequency of cloud cover will increase in future. It remains unclear, however, how elevated CO2 influences photosynthesis under complex clear versus cloudy sky conditions. Accordingly, diurnal changes in photosynthetic responses among beech trees grown at ambient (AC) and doubled (EC) CO2 concentrations were studied under contrasting sky conditions. EC stimulated the daily sum of fixed CO2 and light use efficiency under clear sky. Meanwhile, both these parameters were reduced under cloudy sky as compared with AC treatment. Reduction in photosynthesis rate under cloudy sky was particularly associated with EC-stimulated, xanthophyll-dependent thermal dissipation of absorbed light energy. Under clear sky, a pronounced afternoon depression of CO2 assimilation rate was found in sun-adapted leaves under EC compared with AC conditions. This was caused in particular by stomata closure mediated by vapour pressure deficit. PMID:24316065

  3. Flight test results for a separate surface stability augmented Beech model 99

    NASA Technical Reports Server (NTRS)

    Jenks, G. E.; Henry, H. F.; Roskam, J.

    1977-01-01

    A flight evaluation of a Beech model 99 equipped with an attitude command control system incorporating separate surface stability augmentation (SSSA) was conducted to determine whether an attitude command control system could be implemented using separate surface controls, and to determine whether the handling and ride qualities of the aircraft were improved by the SSSA attitude command system. The results of the program revealed that SSSA is a viable approach to implementing attitude command and also that SSSA has the capability of performing less demanding augmentation tasks such as yaw damping, wing leveling, and pitch damping. The program also revealed that attitude command did improve the pilot rating and ride qualities of the airplane while flying an IFR mission in turbulence. Some disadvantages of the system included the necessity of holding aileron force in a banked turn and excessive stiffness in the pitch axis.

  4. Morphological and molecular identification of the ectomycorrhizal association of Lactarius fumosibrunneus and Fagus grandifolia var. mexicana trees in eastern Mexico.

    PubMed

    Garay-Serrano, Edith; Bandala, Victor Manuel; Montoya, Leticia

    2012-11-01

    A population of Fagus grandifolia var. mexicana (covering ca. 4.7 ha) is established in a montane cloud forest refuge at Acatlan Volcano in eastern Mexico (Veracruz State), and it represents one of only ten populations of this species known to occur in the country (each stand covers ca. 2-35 ha in extension) and one of the southernmost in the continent. Sporocarps of several ectomycorrhizal macrofungi have been observed in the area, and among them, individuals of the genus Lactarius are common in the forest. However, the morphological and molecular characterization of ectomycorrhizae is still in development. Currently, two species of Lactarius have been previously documented in the area. Through the phylogenetic analysis of the internal transcribed spacer (ITS) region from basidiomes and ectomycorrhizae, we identified the Lactarius fumosibrunneus ectomycorrhiza. The host, F. grandifolia var. mexicana, was determined comparing the amplified ITS sequence from ectomycorrhizal root tips in the GenBank database with Basic Local Alignment Search Tool. The mycorrhizal system of L. fumosibrunneus is monopodial-pyramidal, characterized by its shiny, white to silver and pruinose surface, secreting a white latex when damaged, composed of three plectenchymatous mantle layers, with diverticulated terminal elements at the outer mantle. It lacks emanating hyphae, rhizomorphs, and sclerotia. A detailed morphological and anatomical description, illustrations, and photographs of the ectomycorrhiza are presented. The comparison of L. fumosibrunneus and other Lactarius belonging to subgenus Plinthogalus is presented. PMID:22402818

  5. Genome-environment association study suggests local adaptation to climate at the regional scale in Fagus sylvatica.

    PubMed

    Pluess, Andrea R; Frank, Aline; Heiri, Caroline; Lalagüe, Hadrien; Vendramin, Giovanni G; Oddou-Muratorio, Sylvie

    2016-04-01

    The evolutionary potential of long-lived species, such as forest trees, is fundamental for their local persistence under climate change (CC). Genome-environment association (GEA) analyses reveal if species in heterogeneous environments at the regional scale are under differential selection resulting in populations with potential preadaptation to CC within this area. In 79 natural Fagus sylvatica populations, neutral genetic patterns were characterized using 12 simple sequence repeat (SSR) markers, and genomic variation (144 single nucleotide polymorphisms (SNPs) out of 52 candidate genes) was related to 87 environmental predictors in the latent factor mixed model, logistic regressions and isolation by distance/environmental (IBD/IBE) tests. SSR diversity revealed relatedness at up to 150 m intertree distance but an absence of large-scale spatial genetic structure and IBE. In the GEA analyses, 16 SNPs in 10 genes responded to one or several environmental predictors and IBE, corrected for IBD, was confirmed. The GEA often reflected the proposed gene functions, including indications for adaptation to water availability and temperature. Genomic divergence and the lack of large-scale neutral genetic patterns suggest that gene flow allows the spread of advantageous alleles in adaptive genes. Thereby, adaptation processes are likely to take place in species occurring in heterogeneous environments, which might reduce their regional extinction risk under CC. PMID:26777878

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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. PMID:26875186

  8. Tracking the incorporation of 15N from labeled beech litter into mineral-organic associations

    NASA Astrophysics Data System (ADS)

    Kleber, M.; Hatton, P.; Derrien, D.; Lajtha, K.; Zeller, B.

    2008-12-01

    Nitrogen containing organic compounds are thought to have a role in the complex web of processes that control the turnover time of soil organic matter. The sequential density fractionation technique is increasingly used for the purpose of investigating the association of organic materials with the mineral matrix. Organic materials in the denser fractions (>2.0 kg L-1) typically show 13C NMR signals indicative of carbohydrate and aliphatic structures, an absence of lignin and tannin structures and a narrow C:N ratio, suggesting a microbial origin of organic matter in these fractions. Here we take advantage of a labeling experiment conducted at two different sites in Germany and in France to investigate the incorporation of organic nitrogen into physical fractions of increasing density, representing a proximity gradient to mineral surfaces. 15N labeled beech litter was applied to two acidic forest topsoils 8 and 12 years ago. Although there are differences in the distribution patterns between the two soils, and the majority of the organic nitrogen was recovered in fractions representing organic matter of plant origin and not bound to the mineral matrix, our data clearly show that after a decade, significant amounts of the nitrogen had been incorporated in mineral-organic fractions of supposedly slow turnover. It remains to be shown to which extent the N in the densest fractions was incorporated by soil microbiota and associated with mineral surfaces in organic form or adsorbed to mineral surfaces in inorganic form (NH4+).

  9. Simulation of dye adsorption by beech sawdust as affected by pH.

    PubMed

    Batzias, F A; Sidiras, D K

    2007-03-22

    The effect of pH on the batch kinetics of methylene blue adsorption on beech sawdust was simulated, in order to evaluate sawdust potential use as low cost adsorbent for wastewater dye removal. The zero point of charge pH(pzc) of the sawdust, in order to explain the effect of pH in terms of pH(pzc), was measured by the mass titration and the automatic titration methods. The adsorption capacity, estimated according to Freundlich's model, indicate that increase of the pH enhances the adsorption behaviour of the examined material. The lower adsorption of methylene blue at acidic pH is due to the presence of excess H(+) ions that compete with the dye cation for adsorption sites. As the pH of the system increases, the number of positively charged sites decreases while the number of the negatively charged sites increases. The negatively charged sites favour the adsorption of dye cation due to electrostatic attraction. The increase in initial pH from 8.0 to 11.5 increases the amount of dye adsorbed. PMID:16934396

  10. Divergent habitat filtering of root and soil fungal communities in temperate beech forests

    PubMed Central

    Goldmann, Kezia; Schröter, Kristina; Pena, Rodica; Schöning, Ingo; Schrumpf, Marion; Buscot, François; Polle, Andrea; Wubet, Tesfaye

    2016-01-01

    Distance decay, the general reduction in similarity of community composition with increasing geographical distance, is known as predictor of spatial variation and distribution patterns of organisms. However, changes in fungal communities along environmental gradients are little known. Here we show that distance decays of soil-inhabiting and root-associated fungal assemblages differ, and identify explanatory environmental variables. High-throughput sequencing analysis of fungal communities of beech-dominated forests at three study sites across Germany shows that root-associated fungi are recruited from the soil fungal community. However, distance decay is substantially weaker in the root-associated than in the soil community. Variance partitioning of factors contributing to the observed distance decay patterns support the hypothesis that host trees stabilize the composition of root-associated fungi communities, relative to soil communities. Thus, they not only have selective impacts on associated communities, but also buffer effects of changes in microclimatic and environmental variables that directly influence fungal community composition. PMID:27511465

  11. Divergent habitat filtering of root and soil fungal communities in temperate beech forests.

    PubMed

    Goldmann, Kezia; Schröter, Kristina; Pena, Rodica; Schöning, Ingo; Schrumpf, Marion; Buscot, François; Polle, Andrea; Wubet, Tesfaye

    2016-01-01

    Distance decay, the general reduction in similarity of community composition with increasing geographical distance, is known as predictor of spatial variation and distribution patterns of organisms. However, changes in fungal communities along environmental gradients are little known. Here we show that distance decays of soil-inhabiting and root-associated fungal assemblages differ, and identify explanatory environmental variables. High-throughput sequencing analysis of fungal communities of beech-dominated forests at three study sites across Germany shows that root-associated fungi are recruited from the soil fungal community. However, distance decay is substantially weaker in the root-associated than in the soil community. Variance partitioning of factors contributing to the observed distance decay patterns support the hypothesis that host trees stabilize the composition of root-associated fungi communities, relative to soil communities. Thus, they not only have selective impacts on associated communities, but also buffer effects of changes in microclimatic and environmental variables that directly influence fungal community composition. PMID:27511465

  12. Quantitative phenological observations of a mixed beech forest in northern Switzerland with digital photography

    NASA Astrophysics Data System (ADS)

    Ahrends, Hella Ellen; Brügger, Robert; StöCkli, Reto; Schenk, Jürg; Michna, Pavel; Jeanneret, Francois; Wanner, Heinz; Eugster, Werner

    2008-12-01

    Vegetation phenology has a strong influence on the timing and phase of global terrestrial carbon and water exchanges and is an important indicator of climate change and variability. In this study we tested the application of inexpensive digital visible-light cameras in monitoring phenology. A standard digital camera was mounted on a 45 m tall flux tower at the Lägeren FLUXNET/CarboEuropeIP site (Switzerland), providing hourly images of a mixed beech forest. Image analysis was conducted separately on a set of regions of interest representing two different tree species during spring in 2005 and 2006. We estimated the date of leaf emergence based on the levels of the extracted red, green and blue colors. Comparisons with validation data were in accordance with the phenology of the observed trees. The mean error of observed leaf unfolding dates compared with validation data was 3 days in 2005 and 3.6 days in 2006. An uncertainty analysis was performed and demonstrated moderate impacts on color values of changing illumination conditions due to clouds and illumination angles. We conclude that digital visible-light cameras could provide inexpensive, spatially representative and objective information with the required temporal resolution for phenological studies.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  15. Tree-Ring Stable Isotopes Reveal Twentieth-Century Increases in Water-Use Efficiency of Fagus sylvatica and Nothofagus spp. in Italian and Chilean Mountains

    PubMed Central

    Tognetti, Roberto; Lombardi, Fabio; Lasserre, Bruno; Cherubini, Paolo; Marchetti, Marco

    2014-01-01

    Changes in intrinsic water use efficiency (iWUE) were investigated in Fagus sylvatica and Nothofagus spp. over the last century. We combined dendrochronological methods with dual-isotope analysis to investigate whether atmospheric changes enhanced iWUE of Fagus and Nothofagus and tree growth (basal area increment, BAI) along latitudinal gradients in Italy and Chile. Post-maturation phases of the trees presented different patterns in δ13C, Δ13C, δ18O, Ci (internal CO2 concentration), iWUE, and BAI. A continuous enhancement in isotope-derived iWUE was observed throughout the twentieth century, which was common to all sites and related to changes in Ca (ambient CO2 concentration) and secondarily to increases in temperature. In contrast to other studies, we observed a general increasing trend of BAI, with the exception of F. sylvatica in Aspromonte. Both iWUE and BAI were uncoupled with the estimated drought index, which is in agreement with the absence of enduring decline in tree growth. In general, δ13C and δ18O showed a weak relationship, suggesting the major influence of photosynthetic rate on Ci and δ13C, and the minor contribution of the regulation of stomatal conductance to iWUE. The substantial warming observed during the twentieth century did not result in a clear pattern of increased drought stress along these latitudinal transects, because of the variability in temporal trends of precipitation and in specific responses of populations. PMID:25398040

  16. Tree-ring stable isotopes reveal twentieth-century increases in water-use efficiency of Fagus sylvatica and Nothofagus spp. in Italian and Chilean mountains.

    PubMed

    Tognetti, Roberto; Lombardi, Fabio; Lasserre, Bruno; Cherubini, Paolo; Marchetti, Marco

    2014-01-01

    Changes in intrinsic water use efficiency (iWUE) were investigated in Fagus sylvatica and Nothofagus spp. over the last century. We combined dendrochronological methods with dual-isotope analysis to investigate whether atmospheric changes enhanced iWUE of Fagus and Nothofagus and tree growth (basal area increment, BAI) along latitudinal gradients in Italy and Chile. Post-maturation phases of the trees presented different patterns in δ13C, Δ13C, δ18O, Ci (internal CO2 concentration), iWUE, and BAI. A continuous enhancement in isotope-derived iWUE was observed throughout the twentieth century, which was common to all sites and related to changes in Ca (ambient CO2 concentration) and secondarily to increases in temperature. In contrast to other studies, we observed a general increasing trend of BAI, with the exception of F. sylvatica in Aspromonte. Both iWUE and BAI were uncoupled with the estimated drought index, which is in agreement with the absence of enduring decline in tree growth. In general, δ13C and δ18O showed a weak relationship, suggesting the major influence of photosynthetic rate on Ci and δ13C, and the minor contribution of the regulation of stomatal conductance to iWUE. The substantial warming observed during the twentieth century did not result in a clear pattern of increased drought stress along these latitudinal transects, because of the variability in temporal trends of precipitation and in specific responses of populations. PMID:25398040

  17. Stomatal ozone flux and visible leaf injury in native juvenile trees of Fagus sylvatica L.: a field study from the Jizerske hory Mts., the Czech Republic.

    PubMed

    Vlasáková-Matoušková, Leona; Hůnová, Iva

    2015-07-01

    The study was carried out at six sites in the Jizerskehory Mts. in the north of the Czech Republic. At all these sites, ranging in altitude between 460 and 962 m a. s. l., and during the period from June to September in 2008, O3 concentrations and environmental parameters important for accumulated stomatal O3 flux (AFst) into Fagus sylvatica leaves were measured. At five sites, visible injury on Fagus sylvatica L. juvenile tree leaves was observed. A combination of actual O3 levels in the Jizerkehory Mts. and environmental conditions, though relative air humidity and air temperature significantly limited stomatal conductance, has been sufficient enough to cause O3 uptake exceeding the critical level (CL) for forest ecosystems. The AFst values ranged between 13.4 and 22.3 mmol O3 m(-2). The CL for the accumulated stomatal flux of O3 above a flux threshold 1.6 nmol m(-2) s(-1) (AFst1.6) was exceeded at all sites from ca 45 to 270% (160% on average). The CL of 5 ppm h(-1) for AOT40 (accumulated O3 exposure above threshold of 40 ppb) was exceeded at four sites. The relationship between visible injury on O3 indices was found. The conclusions based on AOT40 and AFSt are not the same. AFSt has been determined as better predictor of visible injury than AOT40. PMID:25677787

  18. The age of CO2 emitted from stems and roots of Norway spruce and beech forests in Germany

    NASA Astrophysics Data System (ADS)

    Muhr, J.; Borken, W.; Trumbore, S.

    2012-12-01

    Although pulse-labeling studies follow the fate of recent photosynthetic products over days to months, much less is known about the use of C that was assimilated more than 1 year previously in trees. Trees have the capacity to store C in nonstructural reserves for later use, e.g. when the supply of recent assimilates is insufficient to meet metabolic demands. Comparison of the radiocarbon (14C) signature of CO2 emitted by trees with the observed rate of decline in atmospheric 14C-CO2 provides a measure of the time elapsed between fixation by the plant and return to the atmosphere, thus allowing detection of contribution of older (>1 year-old) C to CO2 efflux. We report radiocarbon data of CO2 that was emitted from tree stems and roots from a Norway spruce (6 dates in 2010/11 for stem CO2, 3 dates in 2011 for root CO2) and from a beech forest (measured in April 2011 just before leaf flush and again in September 2011) in Germany. With the exception of stem CO2 in the spring of 2011, CO2 emitted from tree stems and roots of Norway spruce was always significantly elevated in 14C compared to contemporary atmospheric CO2. The estimated average time elapsed between fixation and emission as CO2 was 1-2 years. For beech, we found seasonal differences. CO2 from tree stems and roots was elevated in 14C in spring, with an estimated average time elapsed since fixation of 4-5 years, whereas we found no differences in 14C to the contemporary atmosphere in autumn, i.e. emitted CO2 predominantly originated from recent (younger than 1 year) photosynthates. Our results imply that C from older, stored C pools contributes to respiration in Norway spruce on a regular basis, while the data for beech suggest a stronger seasonality of the relative contribution of C from older pools to respiration.

  19. Humans in the Hoxnian: habitat, context and fire use at Beeches Pit, West Stow, Suffolk, UK

    NASA Astrophysics Data System (ADS)

    Preece, R. C.; Gowlett, J. A. J.; Parfitt, S. A.; Bridgland, D. R.; Lewis, S. G.

    2006-07-01

    A Lower Palaeolithic industry at Beeches Pit, West Stow, Suffolk, occurs within an interglacial sequence that immediately overlies glacial deposits, referable to the Anglian Lowestoft Formation. There is strong biostratigraphical evidence from both vertebrates and molluscs that the interglacial represented is the Hoxnian (MIS 11). This conclusion is supported by uranium series dates from carbonate nodules (>400 kyr), TL dates from burnt flint (414 +/- 30 kyr) and a range of amino acid racemisation data. The archaeology consists of flint artefacts of Acheulian character, including many refitting examples. Charred material is abundant in three stratigraphical units and many bones and flints have been burnt, indicating repeated occurrence of fire. Several discrete areas of burnt sediment appear to be hearths. This interpretation is supported by: (1) the intensity of burning (600-800°C) implied by the charred and calcined bones; (2) the intersection of two of the burnt areas, implying separate burning events at slightly different, overlapping locations; (3) the discovery of two burnt flakes that refit onto an adjacent group that are unburnt, indicating that the burning was highly localised; and (4) the spatial distribution of artefacts respects the features interpreted as hearths, suggesting fireside knapping. Fossils associated with the archaeology indicate occupation within closed deciduous forest in a fully temperate climate. Attractions to this unusual environment would have included the fresh water provided by springs, a rich supply of potential food and a prolific source of good quality flint for tool manufacture. The archaeological evidence therefore suggests that the site repeatedly served as an area of focused activities (perhaps a home-base) during much of the interglacial. The upper levels of the sequence provide clear faunal evidence of climatic deterioration during which human occupation and fire use persisted. Biostratigraphical correlations with other

  20. Deposition of radiocesium to the soil by stemflow, throughfall and leaf-fall from beech trees.

    PubMed

    Schimmack, W; Förster, H; Bunzl, K; Kreutzer, K

    1993-01-01

    The amount of Chernobyl-derived 137Cs transferred to the soil by stemflow, throughfall (precipitation under the tree crown), and leaf-fall from three beeches was investigated as a function of time in the growing seasons of 1991 and 1992. Up to 70 Bq/week was deposited with the stemflow, mainly in dissolved form (< 0.45 micron) rather than in particulate form (> 0.45 micron). The ratio of dissolved radiocesium to particulate radiocesium was about 10 in the stemflow. It varied considerably with time, but since these variations followed the same pattern for all three trees, they indicated a common cause to be responsible for the fractionation of radiocesium (e.g. meterological conditions for bark weathering). A significant correlation was observed for the amount of dissolved 137Cs (in Bq) and the amount of stemflow (in liters). The 137Cs concentration in the stemflow (in Bq/1), however, decreased with increasing stemflow intensity (in Bq/week). For particulate radiocesium such correlations were not detected. Up to 5 Bq/m2 per week was deposited with the throughfall from the canopy, mainly in particulate form (ratio dissolved radiocesium to particulate radiocesium = 0.34). The mean total annual amounts of 137Cs deposited to the ground (dissolved+particulate) for the three trees were: stemflow: 1991 600 Bq; 1992 460 Bq; throughfall: 1991 and 1992 approximately 100 Bq/m2 each; leaffall: 1992 approximately 10 Bq/m2. The data indicate that at present a substantial amount of the radiocesium in the leaves derives already from root uptake. PMID:8337358

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Biochemical and molecular characterization of methanotrophs in soil from a pristine New Zealand beech forest.

    PubMed

    Singh, Brajesh K; Tate, Kevin

    2007-10-01

    Methane (CH4) oxidation and the methanotrophic community structure of a pristine New Zealand beech forest were investigated using biochemical and molecular methods. Phospholipid-fatty acid-stable-isotope probing (PLFA-SIP) was used to identify the active population of methanotrophs in soil beneath the forest floor, while terminal-restriction fragment length polymorphism (T-RFLP) and cloning and sequencing of the pmoA gene were used to characterize the methanotrophic community. PLFA-SIP suggested that type II methanotrophs were the predominant active group. T-RFLP and cloning and sequencing of the pmoA genes revealed that the methanotrophic community was diverse, and a slightly higher number of type II methanotrophs were detected in the clone library. Most of the clones from type II methanotrophs were related to uncultured pmoA genes obtained directly from environmental samples, while clones from type I were distantly related to Methylococcus capsulatus. A combined data analysis suggested that the type II methanotrophs may be mainly responsible for atmospheric CH4 consumption. Further sequence analysis suggested that most of the methanotrophs detected shared their phylogeny with methanotrophs reported from soils in the Northern Hemisphere. However, some of the pmoA sequences obtained from this forest had comparatively low similarity (<97%) to known sequences available in public databases, suggesting that they may belong to novel groups of methanotrophic bacteria. Different methods of methanotrophic community analysis were also compared, and it is suggested that a combination of molecular methods with PLFA-SIP can address several shortcomings of stable isotope probing. PMID:17696992

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

    PubMed

    Knapp, Michael; Stöckler, Karen; Havell, David; Delsuc, Frédéric; Sebastiani, Federico; Lockhart, Peter J

    2005-01-01

    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. PMID:15660155

  4. Tree girdling as a tool to study plant-microbe C- and N interactions in beech rhizsophere

    NASA Astrophysics Data System (ADS)

    Dannenmann, Michael; Simon, Judy; Gasche, Rainer; Pena, Rodica; Polle, Andrea; Rennenberg, Heinz; Papen, Hans

    2010-05-01

    Nitrogen cycling in terrestrial ecosystems is complex since it involves the closely interwoven processes of both N uptake by plants and microbial turnover of a variety of N metabolites. Major interactions between plants and microorganisms involve competition for the same N species, provision of plant nutrients by microorganisms and labile carbon supply to microorganisms by plants via root exudation. Despite these close links between microbial N metabolism and plant N uptake, only few studies tried to overcome isolated views of plant N acquisition or microbial N fluxes. Here we studied competitive patterns of N fluxes in a mountainous beech forest ecosystem between both plants and microorganisms by reducing rhizodeposition by tree girdling. Besides labile C and N pools in soil, we investigated total microbial biomass in soil, microbial N turnover (N mineralization, nitrification, denitrification, microbial immobilization) as well as microbial community structure using denitrifiers and mycorrhizal fungi as model organisms for important functional groups. Furthermore, plant uptake of organic and inorganic N and N metabolite profiles in roots were determined. Surprisingly plants preferred organic over inorganic nitrogen and nitrate over ammonium in all treatments. Microbial N turnover and microbial biomass were in general negatively correlated to plant nitrogen acquisition and plant nitrogen pools, thus indicating strong competition for nitrogen between plants and free living microorganisms. The abundance of the dominant mycorrhizal fungi Cenococcum geophilum was negatively correlated to total soil microbial biomass but positively correlated to glutamine uptake by beech and amino acid concentration in fine roots indicating a significant role of this mycorrhizal fungus in the acquisition of organic N by beech. Tree girdling in general resulted in a decrease of dissolved organic carbon and total microbial biomass in soil while the abundance of Cenococcum geophilum

  5. Migration and population expansion of Abies, Fagus, Picea, and Quercus since 15000 years in and across the Alps, based on pollen-percentage threshold values

    NASA Astrophysics Data System (ADS)

    van der Knaap, W. O.; van Leeuwen, Jacqueline F. N.; Finsinger, Walter; Gobet, Erika; Pini, Roberta; Schweizer, Astrid; Valsecchi, Verushka; Ammann, Brigitta

    2005-03-01

    Aims: The aim of this study is to explore the migration (colonization of new areas) and subsequent population expansion (within an area) since 15 ka cal BP of Abies, Fagus, Picea, and Quercus into and through the Alps solely on the basis of high-quality pollen data. Methods: Chronologies of 101 pollen sequences are improved or created. Data from the area delimited by 45.5-48.1°N and 6-14°E are summarized in three ways: (1) in a selection of pollen-percentage threshold maps (thresholds 0.5%, 1%, 2%, 4%, 8%, 16%, and 32% of land pollen); (2) in graphic summaries of 250-year time slices and geographic segments (lengthwise and transverse in relation to the main axis of the Alps) as pollen-percentage curves, pollen-percentage difference curves, and pollen-percentage threshold ages cal BP graphed against both the length and the transverse Alpine axes; and (3) in tables showing statistical relationships of either pollen-percentage threshold ages cal BP or pollen expansion durations (=time lapse between different pollen-percentage threshold ages cal BP) with latitude, longitude, and elevation; to establish these relationships we used both simple linear regression and multiple linear regression after stepwise-forward selection. Results: The statistical results indicate that (a) the use of pollen-percentage thresholds between 0.5% and 8% yield mostly similar directions of tree migration, so the method is fairly robust, (b) Abies migrated northward, Fagus southward, Picea westward, and Quercus northward; more detail does not emerge due to an extreme scarcity of high-quality data especially along the southern foothills of the Alps and in the eastern Alps. This scarcity allows the reconstruction of one immigration route only of Abies into the southern Alps. The speed of population expansion (following arrival) of Abies increased and of Picea decreased during the Holocene, of Fagus it decreased especially during the later Holocene, and of Quercus it increased especially at the

  6. Photosynthetic traits of Siebold's beech seedlings in changing light conditions by removal of shading trees under elevated CO₂.

    PubMed

    Watanabe, M; Kitaoka, S; Eguchi, N; Watanabe, Y; Satomura, T; Takagi, K; Satoh, F; Koike, T

    2016-01-01

    The purpose of this study was to obtain basic information on acclimation capacity of photosynthesis in Siebold's beech seedlings to increasing light intensity under future elevated CO2 conditions. We monitored leaf photosynthetic traits of these seedlings in changing light conditions (before removal of shade trees, the year after removal of shade trees and after acclimation to open conditions) in a 10-year free air CO2 enrichment experiment in northern Japan. Elevated CO2 did not affect photosynthetic traits such as leaf mass per area, nitrogen content and biochemical photosynthetic capacity of chloroplasts (i.e. maximum rate of carboxylation and maximum rate of electron transport) before removal of the shade trees and after acclimation to open conditions; in fact, a higher net photosynthetic rate was maintained under elevated CO2 . However, in the year after removal of the shade trees, there was no increase in photosynthesis rate under elevated CO2 conditions. This was not due to photoinhibition. In ambient CO2 conditions, leaf mass per area and nitrogen content were higher in the year after removal of shade trees than before, whereas there was no increase under elevated CO2 conditions. These results indicate that elevated CO2 delays the acclimation of photosynthetic traits of Siebold's beech seedlings to increasing light intensity. PMID:26307372

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

    NASA Astrophysics Data System (ADS)

    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

  8. Black-carbon-surface oxidation and organic composition of beech-wood soot aerosols

    NASA Astrophysics Data System (ADS)

    Corbin, J. C.; Lohmann, U.; Sierau, B.; Keller, A.; Burtscher, H.; Mensah, A. A.

    2015-03-01

    Soot particles are the most strongly light-absorbing particles commonly found in the atmosphere. They are major contributors to the radiative budget of the Earth and to the toxicity of atmospheric pollution. Atmospheric aging of soot may change its health- and climate-relevant properties by oxidizing the primary black carbon (BC) or organic particulate matter (OM) which, together with ash, comprise soot. This atmospheric aging, which entails the condensation of secondary particulate matter as well as the oxidation of the primary OM and BC emissions, is currently poorly understood. In this study, atmospheric aging of wood-stove soot aerosols was simulated in a continuous-flow reactor. The composition of fresh and aged soot particles was measured in real time by a dual-vaporizer aerosol-particle mass spectrometer (SP-AMS). The SP-AMS provided information on the OM, BC, and surface composition of the soot. The OM appeared to be generated largely by cellulose and/or hemicellulose pyrolysis, and was only present in large amounts when new wood was added to the stove. BC signals otherwise dominated the mass spectrum. These signals consisted of ions related to refractory BC (rBC, C+1-5), oxygenated surface groups (CO+1-2), potassium (K+) and water (H+2O and related fragments). The C+4 : C+3 ratio, but not the C+1 : C+3 ratio, was consistent with the BC-structure trends of Corbin et al. (2015c). The CO+1-2 signals likely originated from BC surface groups: upon aging, both CO+ and CO+2 increased relative to C+1-3 while CO+2 simultaneously increased relative to CO+. Factor analysis (PMF) of SP-AMS and AMS data, using a new error model to account for peak-integration uncertainties, indicated that the surface composition of the BC was approximately constant across all stages of combustion for both fresh and aged samples. These results represent the first time-resolved measurements of in-situ BC-surface aging and suggest that the surface of beech-wood BC may be modelled as a

  9. Black carbon surface oxidation and organic composition of beech-wood soot aerosols

    NASA Astrophysics Data System (ADS)

    Corbin, J. C.; Lohmann, U.; Sierau, B.; Keller, A.; Burtscher, H.; Mensah, A. A.

    2015-10-01

    composition of the BC was approximately constant across all stages of combustion for both fresh and aged samples. These results represent the first time-resolved measurements of in situ BC surface aging and suggest that the surface of beech-wood BC may be modelled as a single chemical species.

  10. Impact of repeated dry-wet cycles on soil CO2 efflux in a beech forest

    NASA Astrophysics Data System (ADS)

    Leitner, Sonja; Saronjic, Nermina; Kobler, Johannes; Holtermann, Christian; Zechmeister-Boltenstern, Sophie; Zimmermann, Michael

    2015-04-01

    Climate change research predicts that both frequency and intensity of weather extremes such as severe droughts and heavy rainfall events will increase in mid Europe over the next decades. Because soil moisture is one of the major factors controlling microbially-driven soil processes, a changed moisture regime will impact soil organic matter (SOM) decomposition and nutrient cycling. This in turn can lead to feedback effects between altered precipitation and changed soil CO2 fluxes which can intensify climate change. Soil microorganisms can go into a state of dormancy or form inactive cysts to protect themselves from osmotic stress during soil drying. However, severe droughts increase microbial mortality which slows down SOM decomposition and decreases soil CO2 efflux. The rewetting of dry soil, on the other hand, causes large CO2 emissions, which is also known as the "Birch effect". Until today it is not clear whether these CO2 peaks outweigh the drought-induced decrease of total CO2 efflux. To investigate the impact of repeated dry-wet cycles on soil CO2 efflux we are conducting a precipitation manipulation experiment in a temperate Austrian beech forest. Roofs exclude rainfall and simulate drought periods, and heavy rainfall events are simulated with a sprinkler system. We apply repeated dry-wet cycles in two intensities: one treatment receives 6 cycles of 1 month drought followed by 75mm irrigation, and a parallel treatment receives 3 cycles of 2 months drought followed by 150mm irrigation. Soil CO2 efflux is constantly monitored with an automated flux chamber system, and environmental parameters are recorded via dataloggers. Our results show that droughts significantly reduce soil CO2 effluxes, and that the reductions depend on the length of the drought periods, with longer droughts leading to stronger reductions of CO2 effluxes. In the first 24 to 48h after rewetting, CO2 emissions strongly increased, and then slowly decreased again. Soil CO2 efflux was