| simultaneous growth and emission measurements demonstrate an interactive control of methanol release by leaf expansion and stomata. | emission from plants is a major source of atmospheric methanol. growing tissues contribute most to plant-generated methanol in the atmosphere, but there is still controversy over biological and physico-chemical controls of methanol emission. methanol as a water-soluble compound is thought to be strongly controlled by gas-phase diffusion (stomatal conductance), but growth rate can follow a different diurnal rhythm from that of stomatal conductance, and the extent to which the emission control is ... | 2007 | 17374874 |
| distribution of uv-shielding of the epidermis of sun and shade leaves of the beech (fagus sylvatica l.) as monitored by multi-colour fluorescence imaging. | plants can protect against damaging ultraviolet (uv) radiation by accumulating uv-absorbing substances in the epidermis of the leaves. sun and shade leaves of a free standing beech tree (fagus sylvatica l.) were studied for the differences in uv-shielding of the epidermis by means of multi-colour fluorescence images taken with uv and blue excitation. the distribution of the fluorescence intensity was detected over intact leaves in the emission maxima in the blue at 440 nm (f440), in the green at ... | 2006 | 17126731 |
| modelling ozone effects on adult beech trees through simulation of defence, damage, and repair costs: implementation of the casiroz ozone model in the anafore forest model. | ozone affects adult trees significantly, but effects on stem growth are hard to prove and difficult to correlate with the primary sites of ozone damage at the leaf level. to simulate ozone effects in a mechanistic way, at a level relevant to forest stand growth, we developed a simple ozone damage and repair model (casiroz model) that can be implemented into mechanistic photosynthesis and growth models. the model needs to be parameterized with cuvette measurements on net photosynthesis and dark r ... | 2007 | 17357024 |
| evidence that branch cuvettes are reasonable surrogates for estimating o3 effects in entire tree crowns. | within the scope of quantifying ozone (o(3)) effects on forest tree crowns it is still an open question whether cuvette branches of adult trees are reasonable surrogates for o(3) responses of entire tree crowns and whether twigs exhibit autonomy in defense metabolism in addition to carbon autonomy. therefore, cuvette-enclosed branches of mature beech (fagus sylvatica) trees were compared with branches exposed to the same and different ozone regimes by a free-air fumigation system under natural s ... | 2007 | 17357023 |
| differences in photosynthetic activity, chlorophyll and carotenoid levels, and in chlorophyll fluorescence parameters in green sun and shade leaves of ginkgo and fagus. | the differences in pigment levels and photosynthetic activity of green sun and shade leaves of ginkgo (ginkgo biloba l.) and beech (fagus sylvatica l.) are described. sun leaves of both tree species possessed higher levels in chlorophylls (chl) and carotenoids on a leaf area basis, higher values for the ratio chl a/b and lower values for the ratio chl/carotenoids (a+b)/(x+c) in comparison to shade leaves. the higher photosynthetic rates p(n) of sun leaves (ginkgo 5.4+/-0.9 and beech 8.5+/-2.1 mi ... | 2007 | 17074414 |
| variability in radial sap flux density patterns and sapwood area among seven co-occurring temperate broad-leaved tree species. | forest transpiration estimates are frequently based on xylem sap flux measurements in the outer sections of the hydro-active stem sapwood. we used granier's constant-heating technique with heating probes at various xylem depths to analyze radial patterns of sap flux density in the sapwood of seven broad-leaved tree species differing in wood density and xylem structure. study aims were to (1) compare radial sap flux density profiles between diffuse- and ring-porous trees and (2) analyze the relat ... | 2008 | 19193565 |
| gas exchange and antioxidative compounds in young beech trees under free-air ozone exposure and comparisons to adult trees. | three-year-old beech (fagus sylvatica) seedlings growing in containers were placed into the sun and shade crown of a mature beech stand exposed to ambient (1 x o(3)) and double ambient (2 x o(3)) ozone concentrations at a free-air exposure system ("kranzberg forst", germany). pigments, alpha-tocopherol, glutathione, ascorbate, and gas exchange were measured in leaves during 2003 (a drought year) and 2004 (an average year). sun-exposed seedlings showed higher contents of antioxidants, xanthophyll ... | 2007 | 17357021 |
| effects of long-term, free-air ozone fumigation on the cytokinin content of mature beech trees. | we present the results of a study of the effects of chronic exposure to elevated ozone on the cytokinins of mature beech trees. methods for analysing the cytokinin (ck) content of beech (fagus sylvatica) were developed using seven enzyme-linked immunosorbent assays (elisas). samples taken during 2003 and 2004 from 10 mature beech trees in kranzberg forest, 5 trees exposed to twice ambient ozone (2 x o(3)) by free-air fumigation and 5 control trees (1 x o(3)), were analysed. in 2003 and 2004 the ... | 2007 | 17357020 |
| exemplifying whole-plant ozone uptake in adult forest trees of contrasting species and site conditions. | whole-tree o3 uptake was exemplified for picea abies, fagus sylvatica and larix decidua in stands at high and low altitude and contrasting water availability through sap flow measurement in tree trunks, intrinsically accounting for drought and boundary layer effects on o3 flux. o3 uptake of evergreen spruce per unit foliage area was enhanced by 100% at high relative to low elevation, whereas deciduous beech and larch showed similar uptake regardless of altitude. the responsiveness of the canopy ... | 2007 | 16996178 |
| tree internal signalling and defence reactions under ozone exposure in sun and shade leaves of european beech (fagus sylvatica l.) trees. | the influence of free-air ozone (o(3)) fumigation on the levels of gene transcripts and compounds of defence and signalling were analysed in leaves of adult beech trees from the "kranzberg forest" research site in 2003 and 2004. this includes the precursor of the stress hormone ethylene, acc (1-aminocyclopropane-1-carboxylic acid), conjugated salicylic acid, lignin content as well as of the expression level of genes connected with oxidative stress and stress signalling. at this site mature beech ... | 2007 | 17357019 |
| effects of long-term free-air ozone fumigation on delta15n and total n in fagus sylvatica and associated mycorrhizal fungi. | patterns of nitrogen (n) isotope composition (delta(15)n) and total n contents were determined in leaves, fine roots, root-associated ectomycorrhizal fungi (ecm) of adult beech trees (fagus sylvatica), and soil material under ambient (1 x o(3)) and double ambient (2 x o(3)) atmospheric ozone concentrations over a period of two years. from fine root to leaf material delta(15)n decreased consecutively. under enhanced ozone concentrations total n was reduced in fine roots and delta(15)n showed a de ... | 2007 | 17357018 |
| antioxidative defence of old growth beech (fagus sylvatica) under double ambient o3 concentrations in a free-air exposure system. | in this study the influence of chronic free-air ozone exposure and of different meteorological conditions in the very dry year 2003 and the more humid year 2004 on the antioxidative system in sun and shade leaves of adult fagus sylvatica trees were investigated. contents of ascorbate, glutathione, and alpha-tocopherol, as well as chloroplast pigments were determined under ambient (1 x o(3)) and double ambient (2 x o(3)) ozone concentrations. ozone affected the antioxidative system in june and ju ... | 2007 | 17357016 |
| carbon isotopic composition and oxygen isotopic enrichment in phloem and total leaf organic matter of european beech (fagus sylvatica l.) along a climate gradient. | 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 ... | 2006 | 16898013 |
| a simple general method to evaluate intra-specific transpiration parameters within and among seedling families. | a method to evaluate the genetic control of plant response to increasing soil water deficit is proposed. a description of single tree transpiration behavior was obtained considering parameters independent from air and soil conditions. we removed environmental effects by using two approaches: the normalization of drought data to control (watered) plants and the fitting of a process model. we analyzed the transpiration of 475 4-year-old european beech seedlings, belonging to eight full-sib familie ... | 2006 | 16794836 |
| flux-based response of sucrose and starch in leaves of adult beech trees (fagus sylvatica l.) under chronic free-air o3 fumigation. | investigations on sucrose and starch contents in leaves of 60-year-old beech trees ( fagus sylvatica l.) are the focus of the present study. five trees were exposed to a twice ambient ozone regime (2 x o(3)) with a free-air canopy exposure system throughout the seasons and five trees under the prevailing ambient ozone regime served as controls (1 x o(3)). in order to examine chronic ozone (o(3)) effects, leaf samples from the sun and shade crowns of the trees were analyzed five times throughout ... | 2007 | 17357015 |
| o3 flux-related responsiveness of photosynthesis, respiration, and stomatal conductance of adult fagus sylvatica to experimentally enhanced free-air o3 exposure. | knowledge of responses of photosynthesis, respiration, and stomatal conductance to cumulative ozone uptake (cou) is still scarce, and this is particularly the case for adult trees. the effect of ozone (o(3)) exposure on trees was examined with 60-year-old beech trees (fagus sylvatica) at a forest site of southern germany. trees were exposed to the ambient o(3) regime (1 x o(3)) or an experimentally elevated twice-ambient o(3) regime (2 x o(3)). the elevated 2 x o (3) regime was provided by means ... | 2007 | 17357014 |
| synopsis of the casiroz case study: carbon sink strength of fagus sylvatica l. in a changing environment--experimental risk assessment of mitigation by chronic ozone impact. | databases are needed for the ozone (o(3)) risk assessment on adult forest trees under stand conditions, as mostly juvenile trees have been studied in chamber experiments. a synopsis is presented here from an integrated case study which was conducted on adult fagus sylvatica trees at a central-european forest site. employed was a novel free-air canopy o(3) fumigation methodology which ensured a whole-plant assessment of o(3) sensitivity of the about 30 m tall and 60 years old trees, comparing res ... | 2007 | 17357012 |
| extensive spatial genetic structure revealed by aflp but not ssr molecular markers in the wind-pollinated tree, fagus sylvatica. | studies of fine-scale spatial genetic structure (sgs) in wind-pollinated trees have shown that sgs is generally weak and extends over relatively short distances (less than 30-40 m) from individual trees. however, recent simulations have shown that detection of sgs is heavily dependent on both the choice of molecular markers and the strategy used to sample the studied population. published studies may not always have used sufficient markers and/or individuals for the accurate estimation of sgs. t ... | 2007 | 17305851 |
| nocturnal stomatal conductance effects on the delta(18)o signatures of foliage gas exchange observed in two forest ecosystems. | we report field observations of oxygen isotope ((18)o) discrimination during nocturnal foliage respiration ((18)delta(r)) in branch chambers in two forest ecosystems: a sitka spruce (picea sitchensis (bong.) carr.) plantation in scotland; and a beech (fagus sylvatica l.) forest in germany. we used observations and modeling to examine the impact of nocturnal stomatal conductance on the (18)o/(16)o (delta(18)o) signatures of foliage gas exchange at night. we found that nocturnal stomatal conductan ... | 2007 | 17242000 |
| temperature responses of growth and wood anatomy in european beech saplings grown in different carbon dioxide concentrations. | effects of temperature on growth and wood anatomy were studied in young european beech (fagus sylvatica l.) grown in 7-l pots for 2.5 years in field-phytotron chambers supplied with an ambient (approximately 400 micromol mol-1) or elevated (approximately 700 micromol mol-1) carbon dioxide concentration ([co2]). temperatures in the chambers ranged in increments of 2 degrees c from -4 degrees c to +4 degrees c relative to the long-term mean monthly (day and night) air temperature in berlin-dahlem. ... | 2007 | 17241968 |
| early responses to acute ozone exposure in two fagus sylvatica clones differing in xeromorphic adaptations: photosynthetic and stomatal processes, membrane and epicuticular characteristics. | two fagus sylvatica l. clones were used to investigate the early responses to acute o3 exposure (150 nl l(-1), i.e., 1.35x ambient hourly peak in rural italy) and whether xeromorphic adaptations affect gas exchange, membrane, and epicuticular responses. one clone originated in a wet and temperate climate in central italy (tuscany); the other clone originated in a warmer and drier climate in the southern-most part of the f. sylvatica distribution (sicily). because of higher base gas exchange rate ... | 2007 | 17180427 |
| polyphenols in the woody roots of norway spruce and european beech reduce ttc. | a common method to determine the vitality of fine root tissue is the measurement of respiratory activity with triphenyltetrazolium chloride (ttc). the colorless ttc is reduced to the red-colored triphenyl formazan (tf) as a result of the dehydrogenase activity of the mitochondrial respiratory chain. however, measurements with woody fine roots of adult norway spruce and european beech trees showed that dead control roots had a high potential to react with ttc. high reactivity was found in boiled ... | 2007 | 17169917 |
| effects of ring-porous and diffuse-porous stem wood anatomy on the hydraulic parameters used in a water flow and storage model. | calibration of a recently developed water flow and storage model based on experimental data for a young diffuse-porous beech tree (fagus sylvatica l.) and a young ring-porous oak tree (quercus robur l.) revealed that differences in stem wood anatomy between species strongly affect the calibrated values of the hydraulic model parameters. the hydraulic capacitance (c) of the stem storage tissue was higher in oak than in beech (939.8 versus 212.3 mg mpa(-1)). model simulation of the elastic modulus ... | 2007 | 17169905 |
| chronic ozone exposure affects leaf senescence of adult beech trees: a chlorophyll fluorescence approach. | accelerated leaf senescence is one of the harmful effects of elevated tropospheric ozone concentrations ([o(3)]) on plants. the number of studies dealing with mature forest trees is scarce however. therefore, five 66-year-old beech trees (fagus sylvatica l.) have been exposed to twice-ambient (2xambient) [o(3)] levels by means of a free-air canopy o(3) exposure system. during the sixth year of exposure, the hypothesis of accelerated leaf senescence in 2xambient [o(3)] compared with ambient [o(3) ... | 2007 | 17150989 |
| summer drought impedes beech seedling performance more in a sub-mediterranean forest understory than in small gaps. | refugia of mixed beech forest persist in the central mountains of the iberian peninsula at the south-western limit of european beech (fagus sylvatica l.) distribution. the lack of beech regeneration is a concern in this region that has experienced reduced rainfall and higher temperatures over the past 30 years. beech is considered especially susceptible to climate change because of its conservative shade-tolerant growth strategy; hence seedling responses to drought stress in gaps and in the unde ... | 2009 | 19203950 |
| efficient extraction of proteins from woody plant samples for two-dimensional electrophoresis. | protein extraction from plant samples is usually challenging due to the low protein content and high level of contaminants. therefore, the 2-de pattern resolution is strongly influenced by the procedure of sample preparation. efficient solubilization of proteins strictly depends on the chaotrope and detergent in the extraction buffer. despite the large number of detergents that have been developed for the use in protein extraction and ief, there is no single compound able to efficiently extract ... | 2006 | 16791823 |
| ozone exposure, defoliation of beech (fagus sylvatica l.) and visible foliar symptoms on native plants in selected plots of south-western europe. | the relationships between crown defoliation of beech, visible foliar symptoms on native vegetation and ozone exposure were investigated on permanent monitoring sites in south-western europe in the years 2000-2002. relationships between defoliation of beech and o3 (seasonal mean, 2-week maximum, aot40) were investigated by means of multiple regression models (11 plots, 1-3 years of data each) and a model based on temporal autocorrelation of defoliation data (14 plots, 1-3 years of data each). dif ... | 2007 | 16777302 |
| preliminary results of modeled ozone uptake for fagus sylvatica l. trees at selected eu/un-ece intensive monitoring plots. | the objective of this study was to establish whether eu and un-ece/icp-forests monitoring data (i) provide the variables necessary to apply the flux-based modeling methods and (ii) meet the quality criteria necessary to apply the flux-based critical level concept. application of this model has been possible using environmental data collected from the eu and un-ece/icp-forests monitoring network in switzerland and italy for 2000-2002. the test for data completeness and plausibility resulted in 6 ... | 2007 | 16777285 |
| physiological performance of beech (fagus sylvatica l.) at its southeastern distribution limit in europe: seasonal changes in nitrogen, carbon and water balance. | to assess the physiological performance of drought-sensitive european beech ( fagus sylvatica l.) under the dry mediterranean climate prevailing at its southeastern distribution limit in europe, we analyzed seasonal changes in carbon, nitrogen and water balance of naturally grown adult trees. we determined the foliar c and n contents, delta13c and delta18o signatures, total soluble non-protein nitrogen compounds (tsnn) in xylem, leaves, and phloem, as well as leaf water potential and photosynthe ... | 2006 | 16435269 |
| transcriptome analysis of ozone-responsive genes in leaves of european beech (fagus sylvatica l.). | suppression subtractive hybridization (ssh) was performed to isolate cdnas representing genes that are differentially expressed in leaves of fagus sylvatica upon ozone exposure. 1248 expressed sequence tags (ests) were obtained from 2 subtractive libraries containing early and late ozone-responsive genes. sequences of 1139 clones (91 %) matched the ebi/ncbi database entries. for 578 clones, no putative function could be assigned. most abundant transcripts were o-methyltransferases, representing ... | 2005 | 16388470 |
| crown allometry and growing space efficiency of norway spruce (picea abies [l.] karst.) and european beech (fagus sylvatica l.) in pure and mixed stands. | in pure and mixed stands of norway spruce ( picea abies [l.] karst.) and european beech ( fagus sylvatica l.) we have analyzed crown allometry and growing space efficiency at the tree level and have scaled this from tree level to stand level production. allometry is quantified by the ratio a between the relative growth rates of laterally and vertically oriented tree dimensions. efficiency parameters, eoc for efficiency in space occupation, eex for efficiency in space exploitation, and ebi for ef ... | 2005 | 16388466 |
| spectral multichannel monitoring of radiation within a mature mixed forest. | a multi-sensor system is described based on fiber optic technology and a diode array spectrometer for near-simultaneous measurement of spectral photon fluence rates (pfr) in the range of 360 nm to 1020 nm with a resolution of 0.8 nm, within a mature norway spruce ( picea abies [l.] karst.) - european beech ( fagus sylvatica l.) stand. 126 space-integrating spherical sensors, deployed in a regular grid above and within the canopy and on the forest floor, are sequentially connected to the spectrom ... | 2005 | 16388465 |
| growth of adult norway spruce (picea abies [l.] karst.) and european beech (fagus sylvatica l.) under free-air ozone fumigation. | this study attempted to detect the impact of ozone on adult trees of norway spruce ( picea abies [l.] karst.) and european beech ( fagus sylvatica l.) in an experimental mixed stand in southern bavaria, germany. the aim was to examine whether there is a decrease in growth when trees are exposed to higher than atmospheric concentrations of ozone. this exposure was put into effect using a free-air fumigation system at tree crown level. growth analysis was carried out on a group of 47 spruce and 36 ... | 2005 | 16388464 |
| shoot growth of mature fagus sylvatica and picea abies in relation to ozone. | epidemiological analysis of sequential growth data may be a tool in assessing ozone sensitivity of mature trees. annual shoot growth of mature fagus sylvatica in 83 swiss permanent forest observation plots and of picea abies in 61 plots was evaluated for 11 and 8 consecutive years, respectively, using branches harvested every 4 years. the data were assessed as annual deviation from average growth and related to fructification, ozone, meteorological parameters, and modelled soil water content usi ... | 2007 | 16793183 |
| hyperspectral virtual imaging system of a fagus sylvatica stand. | | 2005 | 16366276 |
| a mathematical model linking tree sap flow dynamics to daily stem diameter fluctuations and radial stem growth. | to date, models for simulating sap flow dynamics in individual trees with a direct link to stem diameter variation include only the diameter fluctuation driven by a change in stem water storage. this paper reports results obtained with a comprehensive flow and storage model using whole-tree leaf transpiration as the only input variable. the model includes radial stem growth based on lockhart's equation for irreversible cell expansion. it was demonstrated that including growth is essential to obt ... | 2006 | 16356899 |
| (13)c/(12)c isotope labelling to study leaf carbon respiration and allocation in twigs of field-grown beech trees. | in situ (13)c/(12)c isotopic labelling was conducted in field-grown beech (fagus sylvatica) twigs to study carbon respiration and allocation. this was achieved with a portable gas-exchange open system coupled to an external chamber. this method allowed us to subject leafy twigs to co(2) with a constant carbon isotope composition (delta(13)c of -51.2 per thousand) in an open system in the field. the labelling was done during the whole light period at two different dates (in june 2002 and october ... | 2006 | 16345109 |
| coagulation-flocculation of beech condensate: particles size distribution. | beech wood (fagus sylvatica l.) condensate from a steaming operation was studied. the objective of our work was to study the precipitation of these wood extracts in presence of calcium ion after autoxidation at basic ph (8). the autoxidation was carried out at 250 rpm for 30 min, and flocculation was followed up for 30 min. an investigation with a laser sizer mastersizer of malvern has been done in order to study the influence of the agitation on the state of aggregation of the condensate. a neg ... | 2002 | 16290593 |
| competitive strategies in adult beech and spruce: space-related foliar carbon investment versus carbon gain. | in central europe, fagus sylvatica and picea abies represent contrasting extremes in foliage type, crown structure and length of growing season. in order to examine the competitive strategies of these two co-occurring species, we tested the following hypotheses: (1) the space occupied by the foliage of sun branches is characterized by greater foliar mass investment compared to shade branches, (2) the carbon (c) gain per unit of occupied space is greater in sun than in shade branches, and (3) ann ... | 2005 | 16205957 |
| plant-mediated nitrous oxide emissions from beech (fagus sylvatica) leaves. | nitrous oxide (n2o) emission estimates from forest ecosystems are based currently on emission measurements using soil enclosures. such enclosures exclude emissions via tall plants and trees and may therefore underestimate the whole-ecosystem n2o emissions. here, we measured plant-mediated n2o emissions from the leaves of potted beech (fagus sylvatica) seedlings after fertilizing the soil with 15n-labelled ammonium nitrate (15nh4(15)no3), and after exposing the roots to elevated concentrations of ... | 2005 | 16159324 |
| tree species (picea abies and fagus sylvatica) effects on soil water acidification and aluminium chemistry at sites subjected to long-term acidification in the ore mts., czech republic. | the effect of european beech (fagus sylvatica) and norway spruce (picea abies) on acid deposition and soil water chemistry was studied at a site in the ore mts., czech republic, that has been subjected to decades of elevated acidic deposition. dry deposition onto the spruce canopy significantly increased acid input to the soil in comparison to the beech canopy. as a result soil waters were more acidic; al, so4(2-), and no3- concentrations were significantly higher; and ca and k concentrations we ... | 2005 | 16054698 |
| air pollution, precipitation chemistry and forest health in the retezat mountains, southern carpathians, romania. | in the retezat mountains concentrations of o3, no2 and so2 in summer season 2000-2002 were low and below toxicity levels for forest trees. while nh3 concentrations were low in 2000, the 2001 and 2002 concentrations were elevated indicating possibility for increased n deposition to forest stands. more than 90% of the rain events were acidic with ph values <5.5, contributing to increased acidity of soils. crown condition of norway spruce (picea abies) and european beech (fagus sylvatica) was good, ... | 2005 | 16005766 |
| a new scenario for the quaternary history of european beech populations: palaeobotanical evidence and genetic consequences. | here, palaeobotanical and genetic data for common beech (fagus sylvatica) in europe are used to evaluate the genetic consequences of long-term survival in refuge areas and postglacial spread. four large datasets are presented, including over 400 fossil-pollen sites, 80 plant-macrofossil sites, and 450 and 600 modern beech populations for chloroplast and nuclear markers, respectively. the largely complementary palaeobotanical and genetic data indicate that: (i) beech survived the last glacial per ... | 2006 | 16771995 |
| genetic effects of chronic habitat fragmentation in a wind-pollinated tree. | habitat fragmentation poses a serious threat to plants through genetic changes associated with increased isolation and reduced population size. however, the longevity of trees, combined with effective seed or pollen dispersal, can enhance their resistance to these effects. the european beech (fagus sylvatica) dominates forest over large regions of europe. we demonstrate that habitat fragmentation in this species has led to genetic bottlenecks and the disruption of the species' breeding system, l ... | 2006 | 16698935 |
| the importance of atmospheric deposition, charge and atomic mass to the dynamics of minor and rare elements in developing, ageing, and wilted leaves of beech (fagus sylvatica l.). | the amounts of sixty elements in developing, maturing, senescent and wilting leaves, and in the wintering dead leaves attached to the branches, are reported for a beech (fagus sylvatica) forest on mor podzol in south sweden, a site with no local sources of pollution or geological anomalies. the amounts (contents per leaf) of k (potassium), rb (rubidium), cs (caesium), cu (copper) and p (phosphorus) were highest in young leaves, decreasing throughout the growing season and usually in the subseque ... | 2006 | 16603223 |
| immunolocalization of fspk1 correlates this abscisic acid-induced protein kinase with germination arrest in fagus sylvatica l. seeds. | 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 ... | 2006 | 16473890 |
| reduction of proteins during sample preparation and two-dimensional gel electrophoresis of woody plant samples. | protein extraction procedure and the reducing agent content (dtt, dithioerythritol, tributyl phosphine and tris (2-carboxyethyl) phosphine (tcep)) of the sample and rehydration buffers were optimised for european beech leaves and roots and norway spruce needles. optimal extraction was achieved with 100 mm dtt for leaves and needles and a mixture of 2 mm tcep and 50 mm dtt for roots. performing ief in buffers containing hydroxyethyldisulphide significantly enhanced the quality of separation for a ... | 2006 | 16456882 |
| production and scavenging of reactive oxygen species in fagus sylvatica seeds during storage at varied temperature and humidity. | the accumulation of reactive oxygen species (ros) in seed tissues plays an important role in the loss of seed viability during storage. in the present study, we examined whether the loss of germination capacity and viability of beech (fagus sylvatica l.) seeds during storage under different temperatures (4, 20 and 30 degrees c) and relative humidity levels (45% and 75% rh) is associated with: (1) an increase in the level of ros, such as superoxide radical (o2*-), oxygen peroxide (h2o2); and, (2) ... | 2005 | 16146313 |
| hydraulic architecture correlates with bud organogenesis and primary shoot growth in beech (fagus sylvatica). | in beech (fagus sylvatica l.), the number of leaf primordia preformed in the buds determines the length and the type (long versus short) of annual growth units, and thus, branch growth and architecture. we analyzed the correlation between the number of leaf primordia and the hydraulic conductance of the vascular system connected to the buds. terminal buds of short growth units and axillary buds of long growth units on lower branches of mature trees were examined. buds with less than four and mor ... | 2005 | 16137940 |
| genetic variability among beech (fagus sylvatica l.) populations from the sudety mountains, in respect of peroxidase and malate dehydrogenase loci. | individual trees growing in five populations of european beech (fagus sylvatica l.) in the sudety mountains were investigated in respect of variability of peroxidases (2 loci) and malate dehydrogenase (1 locus). differences between populations were illustrated by a dendrogram constructed on the basis of hedrick's (1974) genetic distances. the mean gst coefficient (=0.0333) value demonstrated the higher level of intra-population variability, as compared to the inter-population (dst = 0.0149) vari ... | 2005 | 16110183 |
| impact of fertilization on tree-ring delta15n and delta13c in beech stands: a retrospective analysis. | we studied the effects of two fertilization treatments (n and npkca) on wood nitrogen (n) isotope composition (delta(15)n), water-use efficiency (wue) estimated by carbon isotope composition (delta(13)c) analyses, and ring width of trees in 80-year-old beech (fagus sylvatica l.) stands in the forest of fougères, western france. four replicates were fertilized in two successive years (1973 and 1974), 20 years before core sampling. unfertilized control trees displayed a decreasing delta(15)n trend ... | 2005 | 16105811 |
| three-dimensional in vivo magnetic resonance microscopy of beech (fagus sylvatica l.) wood. | spatial structure and water distribution in branch tissues after mechanical injury were investigated in vivo by three-dimensional (3d) magnetic resonance (mr) microscopy. on a beech tree (fagus sylvatica l.), transplanted in a portable pot, a branch was topped and then mr imaged. high-resolution 3d mr images revealed structures which could not be identified by conventional mr images or by light microscopy. mr measurements confirmed our assumption that moisture content is decreasing towards the w ... | 2005 | 16059737 |
| three-dimensional lamina architecture alters light-harvesting efficiency in fagus: a leaf-scale analysis. | modification of foliage exposition and morphology by seasonal average integrated quantum flux density (qint) was investigated in the canopies of the shade-tolerant late-successional deciduous tree species fagus orientalis lipsky and fagus sylvatica l. because the leaves were not entirely flat anywhere in the canopy, the leaf lamina was considered to be three-dimensional and characterized by the cross-sectional angle between the leaf halves (theta). both branch and lamina inclination angles with ... | 2003 | 12750051 |
| effects of stream acidification on fungal biomass in decaying beech leaves and leaf palatability. | we examined the effect of surface water acidification on rates of decomposition, ergosterol concentrations (as a measure of fungal biomass), and palatability to shredders of common beech leaves (fagus sylvatica l.) in five mountain streams (ph 4.7-7.1). leaf decomposition was significantly faster in the circumneutral streams (ph 6.4-7.1; k > or = 0.00175 d(-1)), when compared to acidic streams (ph 4.7-4.9; k < or = 0.00100 d(-1)). fungal biomass showed no particular trend along the acidification ... | 2003 | 12688687 |
| comparison of ozone uptake and sensitivity between a phytotron study with young beech and a field experiment with adult beech (fagus sylvatica). | chamber experiments on juvenile trees have resulted in severe injury and accelerated loss of leaves along with reduced biomass production under chronically enhanced o3 levels. in contrast, the few studies conducted on adult forest trees in the field have reported low o3 sensitivity. in the present study, young beech in phytotrons was more sensitive to o3 than adult beech in the field, although employed o3 regimes were similar. the hypotheses tested were that: (1) differences in o3 uptake were ca ... | 2005 | 16005761 |
| beech (fagus sylvatica) response to ozone exposure assessed with a chlorophyll a fluorescence performance index. | this paper describes a relationship between ozone exposure, biomass, visual symptoms and a chlorophyll a fluorescence performance index for young beech trees (fagus sylvatica). the plants were exposed to four levels of ozone in open-top fumigation chambers (50, 85, 100% of ambient, and 50% of ambient+30 nl l(-1) ozone) that fluctuated in parallel with ambient ozone during a single growing season. the trees were fumigated in the four treatments with ozone levels corresponding to an aot40 (accumul ... | 2000 | 15092883 |
| seasonal ozone response of mature beech trees (fagus sylvatica) at high altitude in the bavarian forest (germany) in comparison with young beech grown in the field and in phytotrons. | mature beech trees (fagus sylvatica) grown at two different altitudes in the bavarian forest were compared with young beech trees grown at nearby field sites or in phytotrons for their macroscopic and physiological responses to different ozone (o(3)) exposures. cumulative o(3) exposure expressed as the sum of hourly mean concentrations above the canopy ranged between 100 and 150 microl l(-1) h, with the vertical o(3) profiles at the higher altitude site being enhanced by 30%. o(3) profiles at al ... | 2000 | 15092876 |
| above-ground space sequestration determines competitive success in juvenile beech and spruce trees. | a 2-yr phytotron study was conducted to investigate the intra- and inter-specific competitive behaviour of juvenile beech (fagus sylvatica) and spruce (picea abies). competitiveness was analysed by quantifying the resource budgets that occur along structures and within occupied space of relevance for competitive interaction. ambient and elevated co(2) and ozone (o(3)) regimes were applied throughout two growing seasons as stressors for provoking changes in resource budgets, growth and allocation ... | 2005 | 15948841 |
| tree age dependence and within-canopy variation of leaf gas exchange and antioxidative defence in fagus sylvatica under experimental free-air ozone exposure. | we characterized leaf gas exchange and antioxidative defence of two-year-old seedlings and 60-year-old trees of fagus sylvatica exposed to ambient (1 x o3) or two-fold ambient (2 x o3) o3 concentrations (maximum of 150 ppb) in a free-air canopy exposure system throughout the growing season. decline in photosynthesis from sun-exposed to shaded conditions was more pronounced in adult than juvenile trees. seedling leaves and leaves in the sun-exposed canopy had higher stomatal conductance and highe ... | 2005 | 15894415 |
| clustered root distribution in mature stands of fagus sylvatica and picea abies. | distribution of small roots (diameter between 2 mm and 5 mm) was studied in 19 pits with a total of 72 m(2) trench profile walls in pure stands of fagus sylvatica and picea abies. root positions within the walls were marked and transformed into x-coordinates and y-coordinates. in a gis-based evaluation, zones of potential influence around each root were calculated. the total potential influence produced isoline maps of relative root influence zones, thus indicating small root clustering. the que ... | 2005 | 15891852 |
| effects of elevated pco2 and/or po3 on c-, n-, and s-metabolites in the leaves of juvenile beech and spruce differ between trees grown in monoculture and mixed culture. | three and four-year-old saplings of beech (fagus sylvatica l.) and spruce (picea abies (l.) karst.) grown in monoculture and mixed culture were exposed in phytotrons to (1) ambient air, (2) elevated po(3), (3) elevated pco(2), or (4) elevated pco(2) plus elevated po(3). after 5 months, the contents of soluble sugars, starch, soluble amino compounds, non-structural proteins (nsp), as well as reduced (gsh) and oxidized (gssg) glutathione were determined in the leaves of both species in order to as ... | 2005 | 15820662 |
| irradiance and temperature affect the competitive interference of blackberry on the physiology of european beech seedlings. | the potential negative influence of competition from early successional species like blackberry (rubus fruticosus) may be decisive for the natural regeneration success of drought-sensitive beech (fagus sylvatica), especially in the light of climate change. with a split plot glasshouse experiment, we investigated the influence of two air temperature and irradiance levels on the competitive interference of blackberry on the water, nitrogen (n) and carbon (c) balance of beech seedlings under modera ... | 2005 | 15720656 |
| regional variation in canopy transpiration of central european beech forests. | forest hydrologists have hypothesised that canopy transpiration (e(c)) of european temperate forests occurs at rather similar rates in stands with different tree species and hydrologic regimes. we tested this hypothesis by synchronously measuring xylem sap flow in four mature stands of fagus sylvatica along a precipitation gradient with the aim (1) of exploring the regional variability of annual canopy transpiration (e(c(t))) in this species, and (2) of analysing the relationship between precipi ... | 2005 | 15682345 |
| [use of issr-markers for determination of convergent evolutionary relations in fagus genus]. | genetic relationships between members of fagus genus were assessed using issr markers and amplification. the taxonomic status of fagus sylvatica l. and fagus orientalis lypsky. species in ukraine has been ascertained more precisely. intraspecies mean genetic distances were compared according to nei & li and respective dendrogram was constructed with the complete joining method. | 2008 | 15619990 |
| gene flow in european beech (fagus sylvatica l.). | three relatively isolated stands were used to study gene flow in european beech (fagus sylvatica l.) in northern germany. nine allozyme loci (got-b, idh-a, lap-a, mdh-b, mdh-c, mnr-a, 6-pgdh-a, pgi-b and pgm-a) were utilized for multilocus-genotyping adult trees and seeds. expected heterozygosity (he) ranged from 0.325 to 0.351 for the three stands. f(st) revealed that there was small differentiation among stands (mean f(st) = 0.013). the indirect estimates of gene flow (nm) based on the mean f( ... | 2004 | 15609570 |
| stable isotope composition of organic compounds transported in the phloem of european beech--evaluation of different methods of phloem sap collection and assessment of gradients in carbon isotope composition during leaf-to-stem transport. | the analysis of stable isotope composition (delta13c, delta15n, delta18o) of phloem-transported organic matter is a useful tool for assessing short-term carbon and water balance of trees. a major constraint of the general application of this method to trees at natural field sites is that the collection of phloem sap with the "phloem bleeding" technique is restricted to particular species and plant parts. to overcome this restriction, we compared the contents (amino compounds and sugars) and isot ... | 2004 | 15570478 |
| use of x-ray computed microtomography for non-invasive determination of wood anatomical characteristics. | quantitative analysis of wood anatomical characteristics is usually performed using classical microtomy yielding optical micrographs of stained thin sections. it is time-consuming to obtain high quality cross-sections from microtomy, and sections can be damaged. this approach, therefore, is often impractical for those who need quick acquisition of quantitative data on vessel characteristics in wood. this paper reports results of a novel approach using x-ray computed microtomography (microct) for ... | 2004 | 15363784 |
| ionic charge, radius, and potential control root/soil concentration ratios of fifty cationic elements in the organic horizon of a beech (fagus sylvatica) forest podzol. | the root/organic soil concentration ratio; r/s) of 50 cationic mineral elements was related to their ionic properties, including ionic radius (r), ionic charge (z), and ionic potential (z/r or z2/r). the materials studied were ectomycorrhizal beech (fagus sylvatica l.) roots and their almost purely organic soil substrate, the o-horizon (mor; raw humus) of a podzol in south sweden, developed in a site which has been untouched by forestry or other mechanical disturbance since at least 50 years and ... | 2004 | 15262169 |
| water shortage affects the water and nitrogen balance in central european beech forests. | whilst forest policy promotes cultivation and regeneration of beech dominated forest ecosystems, beech itself is a highly drought sensitive tree species likely to suffer from the climatic conditions prognosticated for the current century. taking advantage of model ecosystems with cool-moist and warm-dry local climate, the latter assumed to be representative for future climatic conditions, the effects of climate and silvicultural treatment (different thinning regimes) on water status, nitrogen ba ... | 2004 | 15143437 |
| effects of ozone exposure in open-top chambers on poplar (populus nigra) and beech (fagus sylvatica): a comparison. | rooted cuttings of poplar (populus nigra) and seedlings of beech (fagus sylvatica) were exposed to ozone in open-top chambers for one growing season. three treatments were applied: charcoal-filtered (cf), non-filtered (nf) and non-filtered air plus 30 ppb (nl l(-1)) ozone (nf+). extra ozone was only added on clear days, from 09:00 until 17:00-20:00. the aot40s (accumulated exposure over a threshold of 40 ppb), calculated from april to september were 4055 ppb.h for the nf and 8880 ppb.h for the n ... | 2000 | 15092884 |
| atmospheric input of elements to forest ecosystems: a method of estimation using artificial foliage placed above rain collectors. | usefulness of a method of artificial foliage was tested for estimation of total ionic inputs from the atmosphere to forest ecosystems, as well as of processes relevant to ionic fluxes through tree canopies: uptake, leaching, passive flow. the studies were performed in norway spruce and european beech stands in karkonosze mountains (poland), in 1995-97. artificial leaves of increasing leaf area index: 0, 2, 6 and 12 m(2) m(-2 )were placed above standard rain collectors. it has been found that tot ... | 2000 | 15092848 |
| the influence of o3, no2 and so2 on growth of picea abies and fagus sylvatica in the carpathian mountains. | at 17 long-term pollution monitoring sites throughout the carpathian mountains, tree growth patterns and variation in growth rate were examined to determine relationship of tree growth to specific pollutants. canopy dominant picea abies and fagus sylvatica were selected at each site. basal area increment (bai) values were calculated from raw ring widths and used as an estimate of tree growth. across all sites, bai chronologies were highly variable, therefore local conditions and forest structure ... | 2004 | 15046841 |
| nutrient contents and concentrations in relation to growth of picea abies and fagus sylvatica along a european transect. | mineral nutrition of norway spruce (picea abies (l.) karst.) and beech (fagus sylvatica l.) was investigated along a transect extending from northern sweden to central italy. nitrogen (n) concentrations of needles and leaves in stands growing on acid soils did not differ significantly between central italy and southern sweden (1.0 +/- 0.1 mmol n g(-1) for needles and 1.9 +/- 0.14 mmol n g(-1) for leaves). in both species, foliar n concentrations were highest in germany (1.2 mmol n g(-1) for need ... | 1997 | 14759887 |
| competition modifies effects of enhanced ozone/carbon dioxide concentrations on carbohydrate and biomass accumulation in juvenile norway spruce and european beech. | elevated concentrations of carbon dioxide ([co2]) and ozone ([o3]) affect primary metabolism of trees in opposite ways. we studied their potential interactions on carbohydrate concentrations and contents. two hypotheses currently under debate were tested. (1) stimulation of primary metabolism by prolonged exposure to elevated [co2] does not compensate for the adverse effects of o3 on carbohydrate accumulation and biomass partitioning to the root. (2) growth in a mixed-species planting will repre ... | 2004 | 15234902 |
| morphological and physiological responses of beech (fagus sylvatica) seedlings to grass-induced below ground competition. | we examined morphological and physiological responses of beech (fagus sylvatica l.) seedlings to grass-induced below ground competition in full-light conditions. two-year-old beech seedlings were grown during two growing seasons in 160-l containers in bare soil or with a mixture of five grass species widely represented in semi-natural meadows of central france. at the end of the second growing season, beech seedlings in the presence of grass showed significant reductions in diameter and height g ... | 2004 | 14652213 |
| a rapd, aflp and ssr linkage map, and qtl analysis in european beech (fagus sylvatica l.). | the genetic linkage map of european beech ( fagus sylvatica l.) that we report here is the first to our knowledge. based on a total of 312 markers (28 rapds, 274 aflps, 10 ssrs) scored in 143 individuals from a f(1) full-sib family. two maps (one for each parent) were constructed according to a "two-way pseudo-testcross" mapping strategy. in the male map 119 markers could be clustered in 11 major groups (971 cm), while in the female map 132 markers were distributed in 12 major linkage groups (84 ... | 2004 | 14574454 |
| regeneration of mature norway spruce stands: early effects of selective cutting and clear cutting on seepage water quality and soil fertility. | the cutting of trees influences element turnover in the forest ecosystem. the reduction of plant uptake, as well as an increased mineralization and nitrification due to higher soil temperature and soil moisture, can lead to considerable losses of nutrients from the main rooting zone. this may result in a reduced soil fertility and a decrease in drinking water quality due to high nitrate concentrations in the seepage water. in bavaria (germany) selective cutting is preferred to clear cutting when ... | 2001 | 12805805 |
| ozone sensitivity of fagus sylvatica and fraxinus excelsior young trees in relation to leaf structure and foliar ozone uptake. | during the summer of 2001, 2-year-old fraxinus excelsior and fagus sylvatica plants were subjected to ozone-rich environmental conditions at the regional forest nursery at curno (northern italy). atmospheric ozone concentrations and stomatal conductance were measured, in order to calculate the foliar fluxes by means of a one-dimensional model. the foliar structure of both species was examined (thickness of the lamina and of the individual tissues, leaf mass per area, leaf density) and chlorophyl ... | 2003 | 12804831 |
| a dual 13c and 15n long-term labelling technique to investigate uptake and translocation of c and n in beech (fagus sylvatica l.). | a continuous dual 13co2 and 15nh4(15)no3 labelling experimental set-up is presented that was used to investigate the c and n uptake and allocation within 3-year old beech (fagus sylvatica l.) during one growing season. the c and n allocation pattern was determined after six, twelve and eighteen weeks of growth. the carbon uptake was distinctly different in the three phases examined: the first six weeks after budbreak were dedicated to leaf growth with a r/s (root to shoot) ratio of 0.14 for the ... | 2000 | 11022326 |
| spatial and temporal variability of foliar mineral concentration in beech (fagus sylvatica) stands in northeastern france. | foliar mineral concentration may provide a basis for monitoring the consequences of long-term environmental changes, such as eutrophication and acidification of soils, or increase in atmospheric co(2) concentration. however, analytical drifts and inter-tree and year-to-year variations may confound environmental effects on long-term changes in foliar mineral concentration. we have characterized the relative effects of these potentially confounding factors on foliar carbon, nitrogen, phosphorus, c ... | 2000 | 12651522 |
| leaf photosynthetic characteristics of beech (fagus sylvatica) saplings during three years of exposure to elevated co(2) concentration. | beech (fagus sylvatica l.) seedlings were cultivated from seeds sown in pots or directly in the ground in outdoor chambers that were transparent to solar radiation, and provided either ambient air or co(2)-enriched air (ambient + 350 &mgr;mol mol(-1)). the rooting volume was high in all experiments. in the short-term experiment, potted plants were assigned to a factorial co(2) x nutrient treatment (optimal nutrient supply and severe nutrient shortage) for 1 year. in the long-term experiment, pla ... | 2000 | 12651460 |
| genetic diversity and bark physiology of the european beech (fagus sylvatica): a coevolutionary relationship with the beech scale (cryptococcus fagisuga). | in 1994 and 1995, the degree of infestation by the beech scale (cryptococcus fagisuga lind.) was recorded on 120 beech trees (fagus sylvatica l.) in the pless forest near göttingen, germany. simultaneously, the trees were characterized genetically and compounds of primary and secondary metabolism of beech bark were analyzed. a correlation was established between beech scale infestation and the genotype of the host trees, based on gene locus a of isocitrate dehydrogenase (idh-a). the fraction of ... | 2000 | 12651444 |
| glacial refugia: sanctuaries for allelic richness, but not for gene diversity. | glacial refugia are generally expected to harbor higher levels of genetic diversity than are areas that have been colonized after the retreat of the glaciers because colonization often involves only a few individuals. a new paper by comps et al. challenges this expectation by demonstrating a more complex situation in the european beech fagus sylvatica, for which some measures of genetic diversity are higher in newly colonized areas than in refugia. the key to understanding this counter-intuitive ... | 2001 | 11369091 |
| influence of tree internal n status on uptake and translocation of c and n in beech: a dual 13c and 15n labeling approach. | influence of plant internal nitrogen (n) stocks on carbon (c) and n uptake and allocation in 3-year-old beech (fagus sylvatica l.) was studied in two 15n- and 13c-labeling experiments. in the first experiment, trees were grown in sand and received either no n nutrition (-n treatment) or 4 mm unlabeled n (+n treatment) for 1 year. the -n- and +n-pretreated trees were then supplied with 4 mm 15n and grown in a 13co2 atmosphere for 24 weeks. in the second experiment, trees were pretreated with 4 mm ... | 2001 | 11282579 |
| mechanisms of xylem recovery from winter embolism in fagus sylvatica. | hydraulic conductivity in the terminal branches of mature beech trees (fagus sylvatica l.) decreased progressively during winter and recovered in the spring. the objective of this study was to determine the mechanisms involved in recovery. two periods of recovery were identified. the first recovery of hydraulic conductivity occurred early in the spring, before bud break, and was correlated with the occurrence of positive xylem pressure at the base of the tree trunk. active refilling of the embol ... | 2001 | 11260821 |
| diverging trends between heterozygosity and allelic richness during postglacial colonization in the european beech. | variation at 12 polymorphic isozyme loci was studied in the european beech on the basis of an extensive sample of 389 populations distributed throughout the species range. special emphasis was given to the analysis of the pattern of geographic variation on the basis of two contrasting measures of genetic diversity, gene diversity (h) and allelic richness, and to their relationship. measures of allelic richness were corrected for variation in sample size by using the rarefaction method. as expect ... | 2001 | 11139519 |
| winter north atlantic oscillation effects on the tree rings of the italian beech (fagus sylvatica l.). | climatic signals in beech tree-ring width series from central italy have been studied over different periods of time. prewhitened tree-ring chronologies respond mainly to summer precipitation and they do not correlate in a significant manner with the winter north atlantic oscillation (nao) index. in this high-frequency pattern the nao signs are only found on a small number of rings characterized by being very narrow or wide. by contrast, tree-ring width chronologies in which all the frequency co ... | 2000 | 11049000 |
| water and lipid relations in beech (fagus sylvatica l.) seeds and its effect on storage behaviour. | 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 crystallizatio ... | 2003 | 12667610 |
| the soil food web of two beech forests (fagus sylvatica) of contrasting humus type: stable isotope analysis of a macro- and a mesofauna-dominated community. | the structure of the soil food web in two beech (fagus sylvatica) forests, the göttinger wald and the solling forest (northern germany), was investigated using variations in tissue (15)n concentrations of animal species or taxa. the göttinger wald is located on a limestone plateau and characterized by mull humus with high macrofauna activity, particularly of lumbricidae, diplopoda and isopoda. in contrast, the solling forest is located on a sandstone mountain range and characterized by moder hum ... | 2000 | 28308733 |
| contrasting distribution and seasonal dynamics of carbohydrate reserves in stem wood of adult ring-porous sessile oak and diffuse-porous beech trees. | we tested the hypothesis that broad-leaved forest species with contrasting wood anatomy and hydraulic system (ring-porous versus diffuse-porous) also differ in distribution and seasonal dynamics of carbohydrate reserves in stem wood. total nonstructural carbohydrate (tnc) reserves (starch and sugars) were measured enzymatically in the 10 youngest stem xylem rings of adult oak (quercus petraea (matt.) liebl.) and beech (fagus sylvatica l.) trees during an annual cycle. radial distribution of carb ... | 2002 | 12464573 |
| in situ ageing of fine beech roots (fagus sylvatica) assessed by transmission electron microscopy and electron energy loss spectroscopy: description of microsites and evolution of polyphenolic substances. | root biomass is quantitatively and qualitatively important in most ecosystems, but its contribution to the pool of organic matter in the soil is not clear. this work was designed to specify root ageing on an ultrastructural scale by transmission electron microscopy combined with microanalysis by electron energy loss spectroscopy. this approach is very suitable for studying the soil/plant interface, and for semi-quantitative analysis of the evolution of polyphenolic substances during root evoluti ... | 2002 | 12148242 |
| interdependence of ph, malate concentration, and calcium and magnesium concentrations in the xylem sap of beech roots. | the presence and concentration of mineral nutrients and organic acids were analyzed in root xylem sap of mature beech trees (fagus sylvatica l.). an interdependence between malate concentration, ph, and calcium and magnesium concentrations was observed. significant correlations were found between low ph values and high calcium and magnesium concentrations, low ph values and high malate concentration, and high malate concentration and high total calcium and magnesium concentrations. the observed ... | 1997 | 14759841 |
| influence of photosynthetic photon flux density on growth and transpiration in seedlings of fagus sylvatica. | beech seedlings (fagus sylvatica l.) were grown in various combinations of three photosynthetic photon flux densities (ppfd, 0.7, 7.3 or 14.5 mol m(-2) day(-1)) for two years in a controlled environmental chamber. dry mass of leaves, stem and roots, leaf area and number of leaves, and unit leaf rate were affected by both previous-year and current-year ppfd. number of shoots and length of the main shoot were affected by previous-year ppfd but not by current-year ppfd. number of leaves per shoot d ... | 1997 | 14759883 |
| protozoa, nematoda and lumbricidae in the rhizosphere of hordelymus europeaus (poaceae): faunal interactions, response of microorganisms and effects on plant growth. | interactions among protozoa (mixed cultures of ciliates, flagellates and naked amoebae), bacteria-feeding nematodes (pellioditis pellio schneider) and the endogeic earthworm species aporrectodea caliginosa (savigny) were investigated in experimental chambers with soil from a beechwood (fagus sylvatica l.) on limestone. experimental chambers were planted with the grass hordelymus europeaus l. (poaceae) and three compartments separated by 45-μm mesh were established: rhizosphere, intermediate and ... | 1996 | 28307163 |
| changes in microbial biomass, respiration and nutrient status of beech (fagus sylvatica) leaf litter processed by millipedes (glomeris marginata). | the effect of processing of beech leaf litter (fagus sylvatica l.) of different ages by the diplopodglomeris marginata (villers) on status and turnover of microorganisms was investigated in the laboratory. microbial biomass, basal respiration and metabolic quotient of litter-material from three different beechwood sites of a basalt hill forming a gradient from basalt (upper part of the hill) to limestone (lower part of the hill) were determined each season (february, may, august and november). t ... | 1996 | 28307200 |
| evapotranspiration of beech stands and transpiration of beech leaves subject to atmospheric co(2) enrichment. | beech trees (fagus sylvatica l.) show reduced stomatal conductance and increased leaf area index in response to increased atmospheric co(2) concentration. to determine whether the reduction in stomatal conductance results in lower stand evapotranspiration, we compared transpiration on a leaf-area basis and stand evapotranspiration on a ground-area basis in young european beech trees growing in greenhouses at ambient (360 +/- 34 micro mol mol(-1)) and elevated (698 +/- 10 micro mol mol(-1)) co(2) ... | 2004 | 14967665 |
| xylem sap composition of beech (fagus sylvatica l.) trees: seasonal changes in the axial distribution of sulfur compounds. | during different phases of the annual growth cycle, xylem sap was collected from trunk segments of adult beech (fagus sylvatica l.) trees by the water displacement technique. irrespective of the height of the trunk, both sulfate and reduced sulfur compounds were detected in the xylem sap throughout the year. sulfate was the predominant sulfur compound in all samples analyzed. its concentration in the xylem sap varied between 10 and 350 micro mol l(-1), with highest concentrations in april, short ... | 1994 | 14967689 |
| influence of the moisture content on the composition of the liquid smoke produced in the pyrolysis process of fagus sylvatica l. wood. | the pyrolysis of several samples of sawdust of fagus sylvatica l. wood with different moisture contents was carried out, keeping all other smoke generation parameters constant. however, parameters such as smoke production length and maximum temperature reached were affected by the moisture content of the sample and varied in the different pyrolytic runs. the acidity and the composition of the liquid smokes obtained were determined, this latter by means of gas chromatography/mass spectrometry and ... | 1999 | 10552778 |
| cambium pre-activation in beech correlates with a strong temporary increase of calcium in cambium and phloem but not in xylem cells. | using secondary ion mass spectrometry (sims), calcium was imaged in cambium cells and in the adjacent secondary phloem and xylem cells during the different phases of cambium functioning in beech (fagus sylvatica l.). at the end of the period of quiescence, immediately before the resumption of cell divisions (i.e. at the cambium pre-activation phase), a strong temporary increase of calcium concentration was observed to take place in cambium and phloem but not in xylem cells. | 1998 | 9883274 |
| the expression of an abscisic acid-responsive glycine-rich protein coincides with the level of seed dormancy in fagus sylvatica. | by differential screening of a cdna library constructed from poly (a+) rna of aba-treated seeds of fagus sylvatica l., we have isolated an aba-responsive clone that is present in dormant seeds and under conditions that maintain dormancy, but it tends to disappear under conditions breaking seed dormancy. a search of the sequence data bases showed that the clone codes for a glycine-rich protein and has sequence similarity to rna-binding proteins. the clone, which exibits the characteristics of lea ... | 1997 | 9522463 |