Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| 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 |
| 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 |
| ozone exposure-response relationships for biomass and root/shoot ratio of beech (fagus sylvatica), ash (fraxinus excelsior), norway spruce (picea abies) and scots pine (pinus sylvestris). | current-year seedlings of beech, ash, norway spruce and scots pine were exposed during one growing season to different, but moderate, ozone (o(3)) scenarios representative for switzerland (50, 85, 100% ambient, 50% ambient+30 nl l(-1)) in open-top chambers (otcs) and to ambient o(3) concentrations in the field. biomass significantly decreased with increasing o(3) dose in all species except for spruce. losses of 25.5% (ash), 17.4% (beech), 9.9% (scots pine) were found per 10 microl l(-1) h accumu ... | 2000 | 15092880 |
| 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 |
| 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 |
| assessing the use of delta(13)c natural abundance in separation of root and microbial respiration in a danish beech (fagus sylvatica l.) forest. | 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 ... | 2004 | 15095359 |
| 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 |
| comparisons of delta13c of photosynthetic products and ecosystem respiratory co2 and their responses to seasonal climate variability. | this study investigated the relationship between delta13c of ecosystem components, soluble plant carbohydrates and the isotopic signature of ecosystem respired co2 (delta13cr) during seasonal changes in soil and atmospheric moisture in a beech (fagus sylvatica l.) forest in the central apennine mountains, italy. decrease in soil moisture and increase in air vapour pressure deficit during summer correlated with substantial increase in delta13c of leaf and phloem sap soluble sugars. increases in d ... | 2004 | 15150655 |
| photoinhibition in seedlings of fraxinus and fagus under natural light conditions: implications for forest regeneration? | ash (fraxinus excelsior l.) and beech (fagus sylvatica l.) seedlings were grown in the field under three levels of natural light: (1) open, (2) gap and (3) shade. light acclimation of photosynthesis was characterized by means of modulated chlorophyll a fluorescence of intact leaves and growth parameters were measured at the end of the growing season. measurements of maximum photochemical efficiency (fv/fm) of dark-adapted leaves at intervals through the day showed that ash had a higher fv/fm tha ... | 2004 | 15150656 |
| 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 |
| 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 |
| 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 |
| determination of herbicides in stemflow and throughfall of beeches (fagus sylvatica l.) and in rainfall. | the pesticide contamination of water samples collected in and nearby a beech forest in northern germany was evaluated. for this purpose, a method for the collection of water samples from stemflow and throughfall of beeches (fagus sylvatica l.) and rainfall was developed in response to the demands for the analysis of organic contaminants in water samples. furthermore a sensitive and selective multiresidue method was developed to determine 18 pesticides, frequently used in germany, in aqueous samp ... | 2004 | 15519401 |
| spatial variability of throughfall water under beech (fagus sylvatica l.). | 2004 | 15560239 | |
| 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 |
| quantifying ozone uptake and its effects on the stand level of common beech (fagus sylvatica l.) in southern germany. | stand level o(3) fluxes were calculated using water balance calculations for 21 common beech (fagus sylvatica l.) stands and o(3) data from 20 monitoring stations in southern germany. for this intention, the daily loss of water by evapotranspiration per stand area was set against the daily o(3) uptake. during the last 30 years, o(3) uptake ranges between 0 and 187 mmol ha(-1) d(-1) per stand area. cumulative o(3) uptake (cuo(3)), ranging between 0.1 and 0.7 mmol m(-2) yr(-1) per stand area, show ... | 2005 | 15572218 |
| leaf morphology and chemistry in fagus sylvatica (beech) trees as affected by site factors and ozone: results from conecofor permanent monitoring plots in italy. | during summer 2001, leaf samples were collected from seven beech stands that are part of the italian network of permanent monitoring plots (conecofor). in each plot, sun leaves from the upper crown were collected from five trees and subjected to chemical analysis (c, n, p, s, k, ca and mg) and morphological analysis (area, dry mass, thickness and thickness of individual tissues). based on the measurements, nutrient ratios (n/c, n/k, n/p, n/ca, n/mg, k/ca, mg/ca), sclerophylly indices (leaf mass ... | 2005 | 15574402 |
| 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 |
| [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 |
| variation in throughfall deposition across a deciduous beech (fagus sylvatica l.) forest edge in flanders. | throughfall deposition and canopy exchange of acidifying and eutrophying compounds and major base cations were studied by means of throughfall analysis in a deciduous beech (fagus sylvatica l.) forest edge in belgium over a period of 1 year. throughfall fluxes of cl(-), nh(4)(+) and na(+) were significantly elevated at the forest edge compared to the forest interior. as no edge effect on throughfall water volume could be detected, the observed edge enhancement effects were mainly due to dry depo ... | 2005 | 15626394 |
| 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 |
| 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 |
| effects of management on understory diversity in the forest ecosystems of northern spain. | pine plantations are an alternative to marginal agriculture in many countries, and are often presented as an option that improves biodiversity. however, these plantations can have adverse environmental effects if improperly managed. to evaluate the effect of forest management practices on biodiversity, the diversity, species richness, dominance and frequency of understory woody plant species in different forests of the basque country (northern spain) were compared. plantations of exotic conifers ... | 2004 | 15726282 |
| interspecific interactions between the rare tooth fungi creolophus cirrhatus, hericium erinaceus and h. coralloides and other wood decay species in agar and wood. | creolophus cirrhatus, hericium erinaceus and h. coralloides were paired against over 20 other wood decay fungi from beech (fagus sylvatica) covering a range of ecological strategies, on 2% malt agar (ma), 0.5% ma, 0.5% ma adjusted to -1.25 mpa by addition of kcl, 0.5% ma adjusted to ph 4 with koh/h3po4 and 0.5% ma under 5% o2/30% co2 all at 20 degrees c. creolophus cirrhatus and h. coralloides were also paired against 17 other species in wood, incubated at 20 degrees for 36-38 wk. they were aver ... | 2004 | 15757181 |
| first report of eotetranychus fagi in belgium. | eotetranychus fagi (acari: tetranychidae) was first recorded in belgium on fagus sylvatica in kortrijk in october 2002. in the autumn of 2003 e. fagi was noticed again at several locations in flanders. because f. sylvatica is often used as hedge plants in private gardens, it is expected that further spread of this spider mite will occur in the next few years. | 2004 | 15759433 |
| responses of deciduous forest trees to severe drought in central europe. | in 2003, central europe experienced the warmest summer on record combined with unusually low precipitation. we studied plant water relations and phenology in a 100-year- old mixed deciduous forest on a slope (no ground water table) near basel using the swiss canopy crane (scc). the drought lasted from early june to mid september. we studied five deciduous tree species; half of the individuals were exposed to elevated co(2) concentration ([co(2)]) (530 ppm) using a free-air, atmospheric co(2)-enr ... | 2005 | 15805084 |
| 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 |
| ozone foliar symptoms in woody plant species assessed with ultrastructural and fluorescence analysis. | this paper compares the responses to ozone in five woody species: fagus sylvatica (fs), acer pseudoplatanus (ap), fraxinus excelsior (fe), viburnum lantana (vl) and ailanthus altissima (aa). the hypothesis being tested was that the strategies that plants adopt to resist oxidative pressure are species-specific. the study was carried out on field grown plants in an area in northern italy characterized by elevated levels of ozone pollution. the observations were made both at ultrastructural (using ... | 2005 | 15869654 |
| 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 |
| 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 |
| the effects of humic substances on pinus callus are reversed by 2,4-dichlorophenoxyacetic acid. | the reversal of humic matter-induced inhibition of callus growth and metabolism by 2,4-dichlorophenoxyacetic acid (2,4-d) was studied in pinus laricio. two forest humic fractions (relative molecular mass (mr) > 3500), derived from soil under fagus sylvatica (fs) and abies alba (aa) plantation, were used. pinus laricio callus was grown for a subculture period (4 weeks) on basal murashige and skoog (ms) medium plus forest humic matters (fs or aa), at a concentration of 1 mg c/l, and then was trans ... | 2005 | 15898502 |
| 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 |
| fine roots in stands of fagus sylvatica and picea abies along a gradient of soil acidification. | root length of naturally grown young beech trees (fagus sylvatica l.) was investigated in 26 forest plots of differing base saturation and nitrogen deposition. the relative length of finest roots (<0.25 mm) was found to decrease in soils with low base saturation. a similar reduction of finest roots in plots with high nitrogen deposition was masked by the effect of base saturation. the formation of adventitious roots was enhanced in acidic soils. the analysis of 128 soil profiles for fine roots o ... | 2005 | 15964116 |
| inhibition and stimulation effects in communities of wood decay fungi: exudates from colonized wood influence growth by other species. | the effects of exudates from uncolonized and from partly decayed beech wood on the extension rates of 16 later stage decay fungi were investigated. the partly decayed wood had been colonized by the pyrenomycete eutypa spinosa, or the basidiomycetes fomes fomentarius, stereum hirsutum, and trametes versicolor, all known as common early decay agents in european beech forests. sterilized wood pieces were placed onto 0.5% malt agar, opposite to small agar plugs containing the test fungi. the latter ... | 2005 | 16003479 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| phytophthora kernoviae sp. nov., an invasive pathogen causing bleeding stem lesions on forest trees and foliar necrosis of ornamentals in the uk. | a new phytophthora pathogen of trees and shrubs, previously informally designated phytophthora taxon c, is formally named here as p. kernoviae. p. kernoviae was discovered in late 2003 during surveys of woodlands in cornwall, south-west england, for the presence of another invasive pathogen, p. ramorum. p. kernoviae is self-fertile (homothallic), having plerotic oogonia, often with distinctly tapered stalks and amphigynous antheridia. it produces papillate sporangia, sometimes markedly asymmetri ... | 2005 | 16175787 |
| mycelial responses of hypholoma fasciculare to collembola grazing: effect of inoculum age, nutrient status and resource quality. | the effects of grazing by the collembolan folsomia candida on mycelial foraging patterns of hypholoma fasciculare growing from beech (fagus sylvatica) wood block inocula in trays of non-sterile soil was investigated. the wood inocula differed in size, state of decay (time for which wood has been colonized: 2 yr, 1 yr, 6 and 3 months) and nutrient status (inocula colonized on malt agar or nutrient agar). mycelia were most luxuriant, had greater hyphal coverage and extended more rapidly from 2 yr ... | 2005 | 16175795 |
| stem breakage of trees and energy dissipation during rockfall impacts. | the capacity of individual trees to dissipate the energy released by rockfalls has previously only been quantified based on data obtained from static tree-pulling tests or from dynamic impact tests on wood samples. we predicted that these data are not representative of the maximum amount of energy that can be dissipated by living trees during rockfall impacts. to test this prediction, we carried out rockfall experiments on a forested slope in the french alps. to calculate the rock's energy befor ... | 2006 | 16203715 |
| 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 |
| species-specific allometric scaling under self-thinning: evidence from long-term plots in forest stands. | experimental plots covering a 120 years' observation period in unthinned, even-aged pure stands of common beech (fagus sylvatica), norway spruce (picea abies), scots pine (pinus sylvestris), and common oak (quercus petraea) are used to scrutinize reineke's (1933) empirically derived stand density rule [see text], n=tree number per unit area, [see text]=mean stem diameter), yoda's (1963) self-thinning law based on euclidian geometry ([see text] [see text]=mean biomass per tree), and basic assumpt ... | 2006 | 16247620 |
| 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 |
| microbial community structure and density under different tree species in an acid forest soil (morvan, france). | overexploitation of forests to increase wood production has led to the replacement of native forest by large areas of monospecific tree plantations. in the present study, the effects of different monospecific tree cover plantations on density and composition of the indigenous soil microbial community are described. the experimental site of "breuil-chenue" in the morvan (france) was the site of a comparison of a similar mineral soil under norway spruce (picea abies), douglas fir (pseudotuga menzi ... | 2005 | 16333717 |
| spatial variability and temporal stability of throughfall deposition under beech (fagus sylvatica l.) in relationship to canopy structure. | although the spatial variability of throughfall (tf) in forest ecosystems can have important ecological implications, little is known about the driving factors of within-stand tf variability, particularly in deciduous forests. while the spatial variability of tf water amount and h+ deposition under a dominant beech (fagus sylvatica l.) tree was significantly higher in the leafed period than in the leafless period, the spatial tf deposition patterns of most major ions were similar in both periods ... | 2006 | 16338040 |
| (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 |
| hydroxyproline-rich protein material in wood and lignin of fagus sylvatica. | the nitrogen content, distribution, and amino acid composition of protein material were determined in wood and lignin of fagus sylvatica. the data indicated that the nitrogen originated from hydroxyproline-rich cell wall glycoprotein, about half of which may be bound to the lignin polymer. the implications for lignocellulose biodegradation are discussed. | 1984 | 16346689 |
| 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 |
| hyperspectral virtual imaging system of a fagus sylvatica stand. | 2005 | 16366276 | |
| 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 |
| 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 |
| 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 |
| acclimation to ozone affects host/pathogen interaction and competitiveness for nitrogen in juvenile fagus sylvatica and picea abies trees infected with phytophthora citricola. | in a two-year phytotron study, juvenile trees of european beech (fagus sylvatica) and norway spruce (picea abies) were grown in mixture under ambient and twice ambient ozone (o3) and infected with the root pathogen phytophthora citricola. we investigated the influence of o3 on the trees' susceptibility to the root pathogen and assessed, through a 15n-labelling experiment, the impact of both treatments (o3 exposure and infection) on belowground competitiveness. the hypotheses tested were that: (1 ... | 2005 | 16388467 |
| physiological changes of fagus sylvatica seedlings infected with phytophthora citricola and the contribution of its elicitin "citricolin" to pathogenesis. | beech seedlings were infected with the root rot pathogen phytophthora citricola to study its impact on leaf physiology and water status. net photosynthesis rate decreased two days after inoculation in infected seedlings. in contrast, electron quantum yield of photosystem ii, leaf water potential, and total water consumption were only slightly impaired until 6 dpi. at the same time, wilt symptoms occurred on leaves. these results indicate the involvement of a mobile signal triggering the early ch ... | 2005 | 16388468 |
| beech leaf colonization by the endophyte apiognomonia errabunda dramatically depends on light exposure and climatic conditions. | ozone and light effects on endophytic colonization by apiognomonia errabunda of adult beech trees (fagus sylvatica) and their putative mediation by internal defence compounds were studied at the kranzberg forest free-air ozone fumigation site. a. errabunda colonization was quantified by "real-time pcr" (qpcr). a. errabunda-specific primers allowed detection without interference by dna from european beech and several species of common genera of plant pathogenic fungi, such as mycosphaerella, alte ... | 2005 | 16388469 |
| 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 |
| plant development scores from fixed-date photographs: the influence of weather variables and recorder experience. | in 1944, john willis produced a summary of his meticulous record keeping of weather and plants over the 30 years 1913-1942. this publication contains fixed-date, fixed-subject photography taken on the 1st of each month from january to may, using as subjects snowdrop galanthus nivalis, daffodil narcissus pseudo-narcissus, horse chestnut aesculus hippocastanum and beech fagus sylvatica. we asked 38 colleagues to assess rapidly the plant development in each of these photographs according to a suppl ... | 2006 | 16402207 |
| 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 |
| 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 |
| effects of simultaneous ozone exposure and nitrogen loads on carbohydrate concentrations, biomass, growth, and nutrient concentrations of young beech trees (fagus sylvatica). | beech seedlings were grown under different nitrogen fertilisation regimes (0, 20, 40, and 80 kg nha(-1)yr(-1)) for three years and were fumigated with either charcoal-filtered (f) or ambient air (o3). nitrogen fertilisation increased leaf necroses, aphid infestations, and nutrient ratios in the leaves (n:p and n:k), as a result of decreased phosphorus and potassium concentrations. for plant growth, biomass accumulation, and starch concentrations, a positive nitrogen effect was found, but only fo ... | 2006 | 16458397 |
| 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 |
| grazing by folsomia candida (collembola) differentially affects mycelial morphology of the cord-forming basidiomycetes hypholoma fasciculare, phanerochaete velutina and resinicium bicolor. | cord-forming basidiomycetes are important decomposers of dead wood in forest ecosystems but the impact of mycophagous soil invertebrates on their mycelia are little known. here we investigate the effects of different grazing intensities of collembola (folsomia candida) on mycelial foraging patterns of the saprotrophic cord-forming basidiomycetes hypholoma fasciculare, phanerochaete velutina and resinicium bicolor growing from beech (fagus sylvatica) wood block inocula in dishes of non-sterile so ... | 2006 | 16487694 |
| limited transfer of nitrogen between wood decomposing and ectomycorrhizal mycelia when studied in the field. | transfer of (15)n between interacting mycelia of a wood-decomposing fungus (hypholoma fasciculare) and an ectomycorrhizal fungus (tomentellopsis submollis) was studied in a mature beech (fagus sylvatica) forest. the amount of (15)n transferred from the wood decomposer to the ectomycorrhizal fungus was compared to the amount of (15)n released from the wood-decomposing mycelia into the soil solution as (15)n-nh(4). the study was performed in peat-filled plastic containers placed in forest soil in ... | 2006 | 16598505 |
| 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 |
| characterization of a protein kinase (fspk4) with an acidic domain, regulated by abscisic acid and specifically located in fagus sylvatica l. seeds. | an abscisic acid (aba)-induced cdna fragment encoding a putative serine/threonine protein kinase (pk) was obtained by means of differential reverse transcriptase-polymerase chain reaction (rt-pcr). the full-length clone (fspk4) was isolated from a cdna library constructed using mrna from aba-treated fagus sylvatica l. seeds. this clone contained the 11 catalytic domains present in all pks and a highly acidic domain in the c-terminus. by expressing fspk4 in escherichia coli as a his tag fusion pr ... | 2006 | 16616587 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| overexpression of a protein phosphatase 2c from beech seeds in arabidopsis shows phenotypes related to abscisic acid responses and gibberellin biosynthesis. | a functional abscisic acid (aba)-induced protein phosphatase type 2c (pp2c) was previously isolated from beech (fagus sylvatica) seeds (fspp2c2). because transgenic work is not possible in beech, in this study we overexpressed this gene in arabidopsis (arabidopsis thaliana) to provide genetic evidence on fspp2c2 function in seed dormancy and other plant responses. in contrast with other pp2cs described so far, constitutive expression of fspp2c2 in arabidopsis, under the cauliflower mosaic virus ... | 2006 | 16815952 |
| ophiostoma arduennense sp. nov. (ophiostomatales, ascomycota) from fagus sylvatica in southern belgium. | ophiostoma arduennense sp. nov. is described from several cultures isolated from fagus sylvatica in southern belgium. the species is mainly characterized by globose perithecia with small button-like bases ornamented with brown hyphal hairs of variable length and, long cylindrical necks ending in ostiolate hyphae. it is homothallic with small reniform ascospores and no apparent anamorph. it is closely associated with the ambrosia beetles xyloterus domesticus and x. signatus. its phylogenetic rela ... | 2006 | 16828272 |
| early detection of biscogniauxia nummularia in symptomless european beech (fagus sylvatica l.) by taqman quantitative real-time pcr. | to develop a quantitative real-time pcr (rt pcr) assay for the early detection of biscogniauxia nummularia, a xylariaceous fungus that causes strip-canker and wood decay on european beech (fagus sylvatica l.). | 2006 | 16834718 |
| testing the unifying theory of ozone sensitivity with mature trees of fagus sylvatica and picea abies. | the broad range in plant responses to chronic o(3) exposure compels a search for integrative, underlying principles. one such approach is the unifying theory proposed by reich (1987), which combines the o(3) response of contrasting physiognomic classes of plants on the basis of their intrinsic leaf diffusive conductance and, hence, capacity for o(3) uptake. physiognomic classes differ in the proportional decline in photosynthesis and growth when compared on the basis of cumulative o(3) exposure ... | 2006 | 16877324 |
| 13c labelling reveals different contributions of photoassimilates from infructescences for fruiting in two temperate forest tree species. | the pathways of currently fixed carbon in fruit bearing branchlets were investigated in two temperate forest tree species (carpinus betulus and fagus sylvatica), which differ in texture of their vegetative infructescence tissues (leaf-like in carpinus vs. woody in fagus). during late spring, (13)c pulse-labelling was conducted on girdled, defoliated, girdled plus defoliated and untreated fruiting branchlets of mature trees in situ, to assess changes in c relations in response to the introduced c ... | 2006 | 16883486 |
| 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 |
| natural selection and climate change: temperature-linked spatial and temporal trends in gene frequency in fagus sylvatica. | rapid increases in global temperature are likely to impose strong directional selection on many plant populations, which must therefore adapt if they are to survive. within populations, microgeographic genetic differentiation of individuals with respect to climate suggests that some populations may adapt to changing temperatures in the short-term through rapid changes in gene frequency. we used a genome scan to identify temperature-related adaptive differentiation of individuals of the tree spec ... | 2006 | 16968284 |
| tree species effects on decomposition and forest floor dynamics in a common garden. | we studied the effects of tree species on leaf litter decomposition and forest floor dynamics in a common garden experiment of 14 tree species (abies alba, acer platanoides, acer pseudoplatanus, betula pendula, carpinus betulus, fagus sylvatica, larix decidua, picea abies, pinus nigra, pinus sylvestris, pseudotsuga menziesii, quercus robur, quercus rubra, and tilia cordata) in southwestern poland. we used three simultaneous litter bag experiments to tease apart species effects on decomposition v ... | 2006 | 16995629 |
| does shade improve light interception efficiency? a comparison among seedlings from shade-tolerant and -intolerant temperate deciduous tree species. | here, we tested two hypotheses: shading increases light interception efficiency (lie) of broadleaved tree seedlings, and shade-tolerant species exhibit larger lies than do shade-intolerant ones. the impact of seedling size was taken into account to detect potential size-independent effects on lie. lie was defined as the ratio of mean light intercepted by leaves to light intercepted by a horizontal surface of equal area. seedlings from five species differing in shade tolerance (acer saccharum, be ... | 2006 | 16995917 |
| 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 |
| types of ectomycorrhiza as pollution stress indicators: case studies in slovenia. | mycorrhiza is the main spatial and temporal linkage between different constituents in a forest ecosystem. the functional compatibility and stress tolerance of ectomycorrhizal types is species specific, and therefore the information on the ectomycorrhizal community structure can add to the understanding of processes in forest ecosystems and can also be applied as tools for bioindication of pollution stress in forest soils. we have studied the effects of pollution (n and s) on trees and forest soi ... | 2007 | 17057951 |
| 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 |
| 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 |
| 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 |
| irradiance-induced plasticity in the hydraulic properties of saplings of different temperate broad-leaved forest tree species. | we assessed the irradiance-related plasticity of hydraulic architecture in saplings of betula pendula roth., a pioneer species; acer pseudoplatanus l., fraxinus excelsior l. and quercus robur l., which are post-pioneer light-requiring species; and quercus petraea matt. liebl. and fagus sylvatica l. plants were grown in pots in 36%, 16% and 4% of full sunlight. hydraulic conductance was measured with a high-pressure flow-meter in entire, in situ root systems and in excised shoots. leaf-specific w ... | 2006 | 17169890 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| nurse plants, tree saplings and grazing pressure: changes in facilitation along a biotic environmental gradient. | current conceptual models predict that an increase in stress shifts interactions between plants from competitive to facilitative; hence, facilitation is expected to gain in ecological importance with increasing stress. little is known about how facilitative interactions between plants change with increasing biotic stress, such as that incurred by consumer pressure or herbivory (i.e. disturbance sensu grime). in grazed ecosystems, the presence of unpalatable plants is reported to protect tree sap ... | 2007 | 17279351 |
| 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 |