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PubMed1999

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 gas chromatography with flame ionization detection. The acidity and composition of the liquid smoke produced were affected not only by the moisture content of the sawdust sample but also by the smoke generation length and by the temperature of the process. The highest yields in components were produced from samples with low moisture content that underwent a short pyrolytic process. Some compounds, with important properties from an organoleptic and preservative point of view, were not generated from samples with high moisture content. Equations that closely relate yield of the total components or of groups of components or of individual components with parameters such as moisture content, length of the process, and temperature were obtained; these equations predict yield data of liquid smoke components with a satisfactory degree of approximation.

Flame Ionization↗
PubMed1998

Transcripts of a gene, encoding a small GTP-binding protein from Fagus sylvatica, are induced by ABA and accumulated in the embryonic axis of dormant seeds.

A cDNA clone was selected from a cDNA library constructed using mRNA from ABA-treated Fagus sylvatica L dormant seeds as a template. The clone is highly expressed in the presence of ABA and tends to disappear in stratified seeds. A search of sequence databases showed that the clone encodes a small GTP-binding protein. By means of in situ hybridization, the mRNA has been located in the apical meristem of the embryonic axis and in the central vascular cylinder. Its possible involvement in growth regulation in the embryonic axis of F. sylvatica is discussed.

Abscisic Acid↗
PubMed2002

Molecular cloning of a functional protein phosphatase 2C (FsPP2C2) with unusual features and synergistically up-regulated by ABA and calcium in dormant seeds of Fagus sylvatica.

Phosphorylation/dephosphorylation of proteins is a general mechanism of hormonal signal transduction, including ABA, and serine/threonine protein phosphatases 2C (PP2C, EC 3.1.3.16) have been suggested to play an important role in this process. By means of differential reverse transcriptase-polymerase chain reaction (RT-PCR) and further screening of a cDNA library made from mRNA of ABA-treated Fagus sylvatica L. seeds, a full-length cDNA clone (FsPP2C2) encoding a putative PP2C was obtained. Comparison to the databases revealed high homology to plant PP2C and most features of these enzymes, but unusual characteristics were found within the catalytic domain and the N-terminal region of the amino acid sequence. The coding region of FsPP2C2 was expressed in Escherichia coli as histidine tag fusion protein and shows Mg2+-dependent in vitro phosphatase activity. Transcription of the FsPP2C2 gene is low during seeds stratification at 4 degrees C or under gibberellic acid (GA3) treatment and clearly increases when seeds are treated with ABA and calcium (Ca2+) together, while the addition of calcium chelators (EGTA or TMB-8) decreases its expression. Furthermore, FsPP2C2 is only expressed in ABA-treated tissues, preferentially in seeds, which suggests that this PP2C is specifically induced by ABA in dormant seeds, in a Ca2+-dependent manner, and also in other ABA-treated tissues.

Journal Article↗
PubMed2002

Consequences of elevated CO2, augmented nitrogen-deposition and soil type on the soluble nitrogen and sulphur in the phloem of beech (Fagus sylvatica) and spruce (Picea abies) in a competitive situation.

Mixed spruce-beech plantations grown in large open-top chambers (OTC) were used to study consequences of elevated CO2, nitrogen-deposition and soil type on plant internal nitrogen and sulphur cycling of juvenile beech (Fagus sylvatica L.) and spruce (Picea abies Karst.) in a competitive situation. Processes of re-cycling as a consequence of protein turnover during leaf senescence in autumn were of further interest. For this purpose, phloem sap was collected in September 1998 and analysed for the composition and concentrations of organic and inorganic nitrogen and sulphur compounds. The phloem exudate of spruce showed higher total soluble non-protein nitrogen (TSNN) concentration on calcareous soil than on acidic soil, independent of the treatment. N-fertilization increased the N-concentration of phloem exudate significantly on both soil types, mainly by an increase of Arg and Gln concentrations. Elevated CO2 slightly increased TSNN on calcareous, but not on acidic soil. The combination of elevated CO2 and augmented N-deposition induced a further increase of TSNN on calcareous soil, but caused a lower N-effect on TSNN on acidic soil. Arg, the main TSNN component in phloem exudate, mediated this effect. Since Arg is considered to be a major nitrogen storage compound, it is concluded that in autumn elevated CO2 and augmented N-deposition, influence storage of N rather than N-supply of spruce. An effect of elevated CO2 and augmented N-deposition on GSH and sulphate concentrations in phloem exudate of spruce was not observed on acidic soil. On calcareous soil augmented N-deposition enhanced, elevated CO2 decreased phloem exudate GSH contents. In combination, elevated CO2 compensated the positive effect of N-deposition. The effects of elevated CO2 and augmented N-deposition on phloem sap N- and S-contents described above were not observed for beech trees. Apparently, elevated CO2 and augmented N-deposition did not affect plants internal S and N cycling of beech grown in spruce-beech plantations.

Journal Article↗
PubMed1980

The relationship between acetyl content and sugar composition in expanding leaves of beech (Fagus sylvatica L.).

Samples of beech (Fagus sylvatica) leaves were taken from the time of leaf emergence until leaf fall. They were extracted with boiling aqueous ethanol and the residues analysed for their acetyl-group content and their content of sugars released by acid hydrolysis. The accumulation of acetyl groups closely paralled that of xylose, and the two were present in approximately equimolecular proportions, except during the period of leaf expansion, when the acetyl-group/xylose ratio exceeded 3:2. The galactose present in each leaf reached a maximum as leaf expansion ceased and then declined during the period of rapid xylose accumulation. The results are discussed in relation to the known association of acetyl groups with xylans and pectic substancesand to the disappearance of constituents during cell-wall maturation.

Acetylation↗
PubMed2000

Differences in genetic structure between two Japanese beech (Fagus crenata Blume) stands.

To examine the effects of forest cutting on within-population genetic structure, the genetic structure and variability of two Japanese beech (Fagus crenata Blume) stands with contrasting histories in relation to cutting were investigated. Six hundred and sixty beech trees, covering two hectares in total, were mapped and genetically analysed using nine isozyme loci encoding eight enzyme systems. The proportion of polymorphic loci, the average number of alleles per locus, the effective number of alleles per locus, the expected heterozygosity and the observed heterozygosity were 78, 3.3, 1.31, 0.200 and 0.189, respectively, in a secondary stand (designated AK) cut during the 1920s. Corresponding figures were 78, 3.3, 1.33, 0.203 and 0.193, respectively, in a primary stand designated KU. The inbreeding coefficient and the grand mean of the number of alleles in common (NAC) were 0.055 and 1.684 in AK, and 0. 042 and 1.649 in KU, respectively. The genetic variability was slightly but significantly lower in AK. The genetic structure of the two stands was strikingly different. The proportions of positively significant Moran's I and SND values found in the shortest distance class were 0.86 and 0.38 for AK, and 0.14 and 0.29 for KU, respectively. Furthermore, significant linkage disequilibrium was observed in AK, but none at all in KU. To examine which, if any, differences in the genetic structure would be likely to influence succeeding generations, we simulated a self-thinning process. The simulation suggested that reduced genetic variability and linkage disequilibrium would have significant influence in the AK stand for several generations.

Alleles↗
PubMed2000

Genetic variation of European beech (Fagus sylvatica L.) along an altitudinal transect at Mount Vogelsberg in Hesse, Germany.

Allelic and genotypic variation at 13 different enzyme loci of autochthonous European beech (Fagus sylvatica L.) was investigated in six 110-160-year-old stands growing at elevations between 150 and 660 m above sea level on the western slope of mount Vogelsberg in central Germany. The highest elevated population showed the highest number of effective alleles (Ne), the highest total heterozygosity (He) and the highest population differentiation deltaT. Also, the genotype SKD-A2A3 of shikimate dehydrogenase was significantly more frequent at the two highest elevated stands (P = 11%) than at the three lowest elevated stands (P = 1%). Further differences in genotype frequencies between 11 of 15 stand pairs were elevation independent.

Alcohol Oxidoreductases↗
PubMed2000

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 new carbon. The second growth phase showed a balanced R/S ratio of C allocation and after week 13, the root compartment was the main carbon sink (R/S = 6.97). Nitrogen allocation was more basipetal as compared to carbon. In the second growth phase, R/S of Nnew was 5.57 but fell to 3.54 for the third growth phase probably due to formation of reserves in buds and stem.

Carbon↗
PubMed1997

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-genes, is up-regulated by ABA and down-regulated by GA3. Paclobutrazol abolishes the effect of GA3, which is restored upon addition of GA3. The possible relationship of this Glycine-Rich Protein to seed dormancy in F. sylvatica is discussed.

Abscisic Acid↗
PubMed1992

Influence of nitrogen fertilization on minerals, carbohydrates, amino acids and phenolic compounds in beech (Fagus sylvatica L.) leaves.

Beginning in 1985, plots in a 120-year-old beech (Fagus sylvatica L.) stand in the province of Scania, southern Sweden were fertilized annually with ammonium nitrate. In August 1989, leaves from both fertilized and unfertilized trees were analyzed for mineral nutrients, soluble carbohydrates, amino acids and phenolic compounds. Leaf concentrations of total nitrogen were increased by N fertilization. Ammonium was not detected in the leaves, but NO(3) (-) was increased by up to 65% as a result of N fertilization. Nitrogen fertilization decreased foliar concentrations of P and Cu, leading to a nutrient imbalance relative to N. Of the free amino acids, glutamic acid and aspartic acid predominated and, together with glutamine and asparagine, were significantly increased by N fertilization. The concentrations of amides were 2-4 times higher in fertilized trees than in unfertilized trees. Soluble carbohydrates did not change in response to N fertilization, but total phenolic compounds decreased markedly. The reduced concentration of phenolics may explain the greater susceptibility to parasite attacks of trees exposed to N deposition and excess N.

Journal Article↗
PubMed1993

Seasonal changes in the axial distribution of peroxidase activity in the xylem sap of beech (Fagus sylvatica L.) trees.

Xylem sap was collected from trunk segments of adult beech (Fagus sylvatica L.) trees by water displacement. Peroxidase activity was analyzed in xylem saps collected in different phases of the yearly growth cycle and from different heights up the trunks (up to 14 m). The xylem saps contained two major peroxidase isozymes with acidic isoelectric points of 4.1 and 4.6, respectively. Mean peroxidase activity was low during the emergence of the new leaves and high in summer and in winter. In the cold season, peroxidase activity decreased from the stem base to the top, whereas significant gradients were not observed during the vegetative period.

Journal Article↗
PubMed1994

Uptake and distribution of calcium and phosphorus in beech (Fagus sylvatica) as influenced by aluminum and nitrogen.

We studied the effects of excess nitrogen added as nitrate (NO(3) (-)) or ammonium (NH(4) (+)), or both, on mineral nutrition and growth of beech (Fagus sylvatica L.) plants grown at pH 4.2 in Al-free nutrient solution or in solutions containing 0.1 or 1.0 mM AlCl(3). A high external concentration of NH(4) (+) increased the concentration of nitrogen in roots, stems and leaves. The root/shoot dry weight ratio was less in plants grown in the presence of NH(4) (+) than in plants grown in the presence of NO(3) (-). The concentration of phosphorus in the roots was increased and the concentration of potassium in all parts of the plant was decreased by NH(4) (+). A high external concentration of NO(3) (-) caused a decrease in phosphorus concentrations of the root, stem and leaf. Uptake of (45)Ca(2+) by roots was reduced in the presence of high concentrations of NH(4) (+) or NO(3) (-), and a combination of high concentrations of nitrogen and aluminum further reduced the uptake of (45)Ca(2+). Uptake of phosphate ((32)P) and concentrations of phosphorus in root and shoot were increased when plants were grown in the presence of 0.1 mM Al. Exposure to 1.0 mM Al, however, reduced the concentration of phosphorus in roots and shoots and the reduction was greater when plants were grown in the presence of a high external NO(3) (-) concentration. Aluminum binds to roots, and plants grown in the presence of 1.0 mM Al had a slightly higher concentration of aluminum in roots than plants grown in the presence of 0.1 mM Al, whereas the concentration of Al in the shoot was increased 2 to 3 times in plants exposed to 1.0 mm Al. Furthermore, the effects of 1.0 mM Al on uptake of other macronutrients were quite different from the effects of 0.1 mM Al. We conclude that 0.1 mM Al facilitates uptake and transport of phosphorus in beech and that between 0.1 and 1.0 mM Al there is a dramatic change in the effects of Al on uptake and transport of divalent cations and phosphorus.

Journal Article↗
PubMed1994

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, shortly before bud break. In contrast to other tree species, cysteine and not glutathione was the predominant thiol transported in the xylem sap of beech trees. The cysteine concentration ranged between 0.1 and 1 micro mol l(-1). As observed for sulfate, maximum cysteine concentrations were found in April. Apparently, both sulfate and cysteine transport contribute to the sulfur supply of the developing leaves. Seasonal changes in the axial distribution of cysteine and sulfate differed, indicating differences in the source-sink relations of these sulfur compounds. High, but uniform, xylem sap sulfate concentrations in April may originate from balanced sulfate uptake by the roots, whereas high cysteine concentrations in April, increasing with increasing height of the trunk, may originate in part from protein breakdown in the trunk. Reversal of the axial distribution of xylem sap cysteine in late summer-early fall to higher concentrations in the lower part of the trunk than in the upper part of the trunk suggests that the upper part of the trunk becomes a sink for cysteine as a result of the synthesis of storage proteins at this time of the year.

Journal Article↗
PubMed1996

Effects of elevated CO(2) concentration on leaf characteristics and photosynthetic capacity of beech (Fagus sylvatica) during the growing season.

Two-year-old beech (Fagus sylvatica L.) saplings were planted directly in the ground at high density (100 per m(2)), in an experimental design that realistically mimicked field conditions, and grown for two years in air containing CO(2) at either ambient or an elevated (ambient + 350 ppm) concentration. Plant dry mass and leaf area were increased by a two-year exposure to elevated CO(2). The saplings produced physiologically distinct types of sun leaves associated with the first and second growth flushes. Leaves of the second flush had a higher leaf mass per unit area and less chlorophyll per unit area, per unit dry mass and per unit nitrogen than leaves of the first flush. Chlorophyll content expressed per unit nitrogen decreased over time in plants grown in elevated CO(2), which suggests that, in elevated CO(2), less nitrogen was invested in machinery of the photosynthetic light reactions. In early summer, the photosynthetic capacity measured at saturating irradiance and CO(2) was slightly but not significantly higher in saplings grown in elevated CO(2) than in saplings grown in ambient CO(2). However, a decrease in photosynthetic capacity was observed after July in leaves of saplings grown in CO(2)-enriched air. The results demonstrate that photosynthetic acclimation to elevated CO(2) can occur in field-grown saplings in late summer, at the time of growth cessation.

Journal Article↗
PubMed1997

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 needles and 2.0 mmol N g(-1) for leaves) and decreased by 50% toward northern Sweden (0.5 mmol N g(-1)). Both species showed constant S/N and P/N ratios along the transect. Calcium, K and Mg concentrations generally reflected local soil conditions; however, Mg concentrations reached deficiency values in Germany. Leaf area per unit dry weight varied significantly along the transect with lowest values for Norway spruce recorded in northern Sweden and Italy (3.4 m(2) kg(-1)) and a maximum in central Europe (4.7 m(2) kg(-1)). A similar pattern was observed for beech. Despite the low variation in foliar N concentrations on the large geographic scale, local and regional variations in N concentrations equalled or exceeded the variation along the entire continental transect. Furthermore, nutrient contents (i.e., nutrient concentration x dry weight per needle or leaf) showed a greater variation than nutrient concentrations along the transect. Nitrogen contents of Norway spruce needles reached minimum values in northern Sweden (2.4 micro mol N needle(-1)) and maximum values in Denmark (5.0 micro mol N needle(-1)). The N content of beech leaves was highest in Denmark (242 micro mol N leaf(-1)). At the German site, foliar N content rather than N concentration reflected the seasonal dynamics of foliar growth and N storage of the two species. During foliage expansion, there was an initial rapid increase in N content and a decrease in N concentration. This pattern lasted for about 2 weeks after bud break and was followed by 6 weeks during which dry weight and N content of the foliage increased, resulting in a further decrease in N concentration. During summer, dry weight and N content of mature needles of Norway spruce increased further to reach a maximum in autumn, whereas N concentration remained constant. In spring, reallocation of N from 1- and 2-year-old needles was 1.5 and 1.0 micro mol N needle(-1), respectively. This remobilized N was a major source of N for the development of new needles, which had an N content of 1.5 micro mol N needle(-1) after bud break. The seasonal remobilization of N from old foliage decreased with increasing needle age. Needle N content and dry weight decreased progressively with age (1 micro mol N needle(-1) between age classes 2 and 5), whereas N concentrations remained constant. For Norway spruce, annual stemwood production was correlated with needle N content but not with foliar N concentration or with the total amount of N in the canopy. Interspecific and geographical differences in plant nutrition are discussed on the basis of competitive demands for C and N between growth of foliage and wood.

Journal Article↗
PubMed1997

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 did not change with PPFD, whereas leaf dry mass/leaf area ratio was mainly affected by current-year PPFD. During the first 10 days that newly emerged seedlings were grown at a PPFD of 0.7 or 14.5 mol m(-2) day(-1), transpiration rate per unit leaf area declined. Thereafter, transpiration increased to a constant new rate. Transpiration rate per seedling was closely related to leaf area but the relationship changed with time. In two-year-old seedlings grown at various PPFD combinations of 0.7, 7.3 and 14.5 mol m(-2) day(-1) during Years 1 and 2, leaf area and transpiration rate per seedling were closely correlated at Weeks 7 and 11 after bud burst. Weak correlations were found between root dry mass and transpiration rate per seedling. During Year 2, transpiration rate per leaf area was higher at a particular PPFD in seedlings grown at a previous-year PPFD of 0.7 mol m(-2) day(-1) than in seedlings grown at a previous-year PPFD of 14.5 mol m(-2) day(-1). After transfer of two-year-old seedlings at the end of the experiment to a new PPFD (7.3 or 14.5 mol m(-2) day(-1)) for one day, transpiration rates per leaf area, measured at the new PPFD, were correlated with leaf area and root dry mass, irrespective of former PPFD treatment.

Journal Article↗
PubMed1998

Effects of current-year and previous-year PPFDs on shoot gross morphology and leaf properties in Fagus japonica.

We investigated how shoot gross morphology and leaf properties are determined in Fagus japonica Maxim., a deciduous species with flush-type shoot phenology, in which all leaves are produced in a single flush at the start of each season. We examined relationships between current-year shoot properties and local light environment in a 14-m tall beech tree growing in a deciduous forest. Leaf number (LN), total leaf area (TLA), and total leaf length (SL) of the current-year shoot increased with increasing photosynthetic photon flux density (PPFD). Leaf thickness, dry mass per leaf area and nitrogen content on a leaf area basis increased, whereas the chlorophyll/N ratio decreased with increasing PPFD. To separate the effects of current-year PPFD from those of previous year(s), we artificially shaded a part of the uppermost leaf tier. Reciprocal transfers of beech seedlings between controlled PPFD regimes were also made. Characteristics of shoot gross morphology such as LN, TLA and SL were largely determined by the PPFD of the previous year. The exception was the length of the longest "long shoots" with many leaves, in which elongation appeared to be influenced by both previous-year and current-year PPFD. In contrast, leaf properties were determined by current-year PPFD. The ecological implications of our findings are discussed.

Journal Article↗
PubMed2000

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, calcium, potassium, magnesium and manganese concentrations in 118 pure beech (Fagus sylvatica L.) stands, sampled in 1969-71 and 1996-97. Interannual fluctuations of these elements were quantified in a subset of six beech stands monitored for 5 years. Intercalibration between the methods used at each sampling period for nitrogen and phosphorus analyses showed significant, but low, relative differences (0.8 and 3.3% for N and P, respectively). Based on inter-tree variability, elements could be arranged in four groups: C (constant), N and P (low variability), K and Ca (medium variability), Mn and Mg (high variability). Inter-tree coefficients of variation were 2, 6, 8, 15, 18, 22 and 27%, respectively. Year-to-year fluctuations increased in the order N, P, Mg, K, Ca, and Mn coefficients of variation of 4, 4, 7, 9, 11, 15 and 29%, respectively). Between the two sampling periods, foliar N concentration increased 12%, whereas decreases were observed for P (-23%), Mg (-38%) and Ca (-16%). Ratios of N/P, N/K and N/Mg increased by 42, 19 and 77%, respectively. These changes were larger than the interannual variations for P, Mg, N/P, N/Mg and Mg/Ca. Decreasing concentrations of P and cations were particularly marked for trees growing on acidic soils, whereas the positive N trend did not depend on soil type. Both increasing atmospheric CO(2) concentrations and acidification of forest soils could contribute to decreasing P and cation concentrations in foliage. The increase in foliar N concentration with time suggests a nitrogen deposition effect. Whatever the causes of these changes, the large shift in element ratios indicates an accelerating imbalance between nitrogen and cation status.

Journal Article↗