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Effect of soil bulk density on forest tree seedlings

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The paper presents the results of an analysis of the influence of soil bulk density in a forest nursery plot on the growth and quality parameters of Scots pine and European beech seedlings. Particular density variants were obtained using a tractor device exerting controlled pressure on the soil, while field examinations were performed on an area of ‘Kłaj’ forest nursery in Niepołomice Forest District. Three series of plots were prepared for each species, applying a unit pressure of the values of 50, 100, 150, 200, 250 kPa, corresponding to the dry bulk density in the range of 1.03-1.19 g cm-3, and control plots without the pressure. Seeds of the examined species were sown on the prepared plots, and after 6 months of growth the seedlings were subjected to biometric analysis determining differentiation in root neck diameter, length of the above-ground part and root system, as well as dry mass of particular parts of the plant. The quality of the seedlings was also determined using the method of Schmidt-Vogt. The results obtained show that the change in dry bulk densitysoil significantly affected most of the growth parameters of theexamined seedlings. Especially high negative correlations were obtained for the length and dry mass of the root system. A significant influence of dry bulk density variant on all growth parameters of Scots pine seedlings, and on some parameters of European beech was demonstrated. An increase in soil bulk density clearly caused also a deterioration of European beech seedlings quality.
The results of research into leaf stomatal variability of five European beech provenances originating from Austria, Bosnia and Hercegovina, Germany, Romania and Serbia are presented in this paper. Aim of the study was to investigate how stomatal traits of provenances originating from different environments change in response to drought stress and to assess the phenotypic plasticity of the stomatal features investigated. The study was conducted during two different years, characterized by contrasting weather conditions (2010 and 2011). Two-way ANOVA revealed that provenances differ significantly in terms of stomatal density (SD), width of stomatal aperture (Wb), potential conductance index (PCI) and relative stomatal pore surface (RSPS), during both seasons. In a dry year (2011) all provenances significantly increased stomatal density by between 16.1% (Hasbruch – DE) and 21.9% (Cer – SRB). Guard cell length (LA) was not statistically different among provenances in either year (2010 and 2011), even though LA decreased in the dry year (2011) in all provenances. Reaction norms were steep in most of the parameters suggesting the possibility of a plastic response of provenances toward changes in soil water regime, influenced by the prevailing weather each year. Phenotypic plasticity indices were the highest in regards of SD, PCI and RSPS, indicating that these traits would be good candidates for improvement in breeding programs aimed at selection of drought resistant.
The activation energy of swelling beech wood (Fagus sylvatica L.) in water. This paper shows the results of the activation energy of swelling beech wood in water. The results showed that activation energy depends on the density. Increasing that values increase activation energy of swelling.
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There are limited published data on in vitro reproduction of Fagus sylvatica L. (European beech). This study was aimed to determine the efficiency of induction of somatic embryogenesis or organogenesis of beech from different types of explants in various culture conditions. Explants derived from immature, fresh seeds (collected in 2011 and 2013) and from mature seeds, stored at –10ºC and some stratified at 3ºC, were placed on induction media with various combinations of plant growth regulators: zeatin, 2,4-dichlorophenoxyacetic acid (2,4-D) and/or benzyladenine (BA). Initial cultures were kept in darkness or weak light (white fluorescent or blue-red LED). Limited success has been achieved in initiation of somatic embryogenesis. We obtained friable, yellow-white callus with characteristic PEM-like structures (cPEM-ls, from embryonic axes or fragments of immature embryos with embryonic axes), which may be an early developmental stage of embryogenic callus of Fagus sylvatica. This type of callus regenerated from explants incubated in darkness, mainly on WPM medium with addition of 6.8 μM zeatin or WPM and MSG media with 9.1 μM 2,4-D and 2.2 μM BA. The highest frequency of regeneration of callus with cPEM-ls was 5%. Instead, we succeeded to induce organogenesis from both immature and mature zygotic embryos and from embryonic axes. The best results were obtained for mature zygotic embryos incubated on ½WPM medium (half-strength Woody Plant Medium) with 9.1 μM 2,4-D and 2.2 μM BA. Adventitious buds were regenerated on up to 15% of the explants. The induced buds developed into shoots, enabling us to establish tissue cultures of beech. Induction of organogenesis from the tested explants was more efficient than induction of somatic embryogenesis.
European beech is a superior competitor among the trees of Central Europe, often growing in pure stands. We proposed a hypothesis, that once beech has reached dominance in forest community, it's recruitment could become limited due to the gradual accumulation of pathogens attacking seeds and seedlings. We employed data on seed production and germination along with a field experiment to estimate the germination success of beech in two old-growth forests. Beech produced more seeds than the co-occurring coniferous trees, but less than 1% of beechnuts germinated in the next season. In the field experiment, the percentage of decayed beechnuts was 57% in the Carpathians and 61% in the Alps. Most of the dead germinants and decayed beechnuts were infested by fungi. The average number of fungal colonies per one sample in the Carpathians was significantly higher after mast year than one year before, while the differences between the Alps and Carpathians after mast years were statistically not significant. Fungi have been isolated from practically all dead beechnuts and dead germinants. The number of beechnuts per seed trap, the number of germinants around it and the relative number of fungal colonies obtained from plastic boxes placed in the same sample plot were not significantly correlated. The mortality of germinants continued throughout the spring; the number of life germinants in the middle of May amounted to 0.87% of the initial number of beechnuts in the Carpathians and only 0.28% in the Alps. High rates of beechnut and germinant mortality could probably offset the huge reproductive effort of European beech in old-growth stands and limit the possibility to attain absolute dominance by that species. However, our hypothesis that the build-up of fungal pathogens on the forest floor old-growth stands is able to stop the regeneration of beech still needs to be tested using larger data sets.
Support of European beech (Fagus sylvatica L.) and sycamore maple (Acer pseudoplatanus L.) plantations by amelioration has been tested in air-polluted sites in the mountains since 1993. The research locality is a site with humic podzol soils at an altitude of 960 m a.s.l. Dolomitic limestone (1 kg per tree) was mixed with soil used for planting tree seedlings. According to the results of a 15-year investigation (1993– 2008), liming had a positive effect on beech tree growth, while the positive effect of liming on tree growth was temporary in the case of sycamores. Ca content was higher in the limed beech plantations throughout the observation period. Soil analyses (sampled in 2002) showed that the application of dolomitic limestone influenced soil conditions markedly in terms of increased pH. The pH values measured in H2O increased from 4.9 to 6.2 for beeches and from 4.3 to 6.1 for sycamores.
The article describes horizontal structure of the tree layer, natural regeneration, snags and crown projections of natural beech stands on three permanent research plots in the wide altitudinal range in the Krkonoše Mts (Czech Republic). The spatial structure was classified from 1980 to 2010 and subsequently the prediction of spontaneous development with an outlook for 30 years (to 2040) was done by growth simulator. Hopkins-Skellam index, Pielou-Mountford index, Clark-Evans index and Ripley’s K-function were calculated. Further, the vertical structure and total diversity index was evaluated. The horizontal structure of individuals in the tree layer had not changed significantly during the monitored years. Tree spatial pattern of the lowest altitude lying herb-rich beech forest was mostly regular to random, in acidophilous mountain beech forest predominantly random and in fragments of beech groups around the timberline aggregated. Juvenile growth on all investigated plots was distributed aggregated and snags randomly. The horizontal structure of crown projection centroids had always higher values toward the regularity than tree layer and was random to regular. The result of principal component analysis also confirmed that spatial pattern was dependent on the altitude, but also on the number of trees.
The European beech is a major component of central European forests, and the eastern limit of its range lies in Poland. However, the Holocene migration of the beech is not yet finished, especially in NE Poland, so the northern distribution of the beech continues to change. The main goal of this study was to determine if the beech will reach its northern limit in the future. The investigation was carried out in 18 beech stands in Poland. To study the status of the health of the trees, circular plots were established in grids of different sizes. The basal beech stand area ranged from 3.7 m² ha⁻¹ to 31.2 m² ha⁻¹. The density of trees exceeded a hundred trees per hectare in most of the plots (61%), and the average degree of defoliation was not greater than 60% in all of the investigated stands. Environmental conditions influenced defoliation of beech trees (Fisher's test, F = 4.0204; P <0.0001). The vitality of the beech trees varied between stands (Kruskal-Walis test, H = 139.7433, P <0.0001) and was rather good in 56% of the study plots. Seedlings and saplings were observed in all of the investigated stands, and they covered from 5 to 39% and 21 to 80% of the study plots, respectively. Spontaneous beech regeneration was widespread and differed from stand to stand as well as within stands in all of the study plots. The number of tall seedlings in most of the study plots (56%) was greater than 10,000 individuals per hectare. The factors limiting beech regeneration were stand density and herb cover, and the number of beech seed trees influenced the quantity of small seedlings. Beech tree density positively influenced the number of small seedlings, and the strength of the correlation was moderate and statistically significant (Pearson correlation, r = 0.349). Beech tree density influenced the vitality of tall and small saplings (Pearson's correlations, r = 0.673 and r = 0.361, respectively). The spontaneous regeneration and strong vitality of seedlings and saplings suggests that beech can create stable stands in the future and that it is an expansive tree species both within its continuous range and at the limit of its distribution. It is quite possible that beech will reach its north-eastern limit in Poland in the future.
European beech is a superior competitor among the trees of Central Europe, often growing in pure stands. We proposed a hypothesis, that once beech has reached dominance in forest community, it's recruitment could become limited due to the gradual accumulation of pathogens attacking seeds and seedlings. We employed data on seed production and germination along with a field experiment to estimate the germination success of beech in two old-growth forests. Beech produced more seeds than the co-occurring coniferous trees, but less than 1% of beechnuts germinated in the next season. In the field experiment, the percentage of decayed beechnuts was 57% in the Carpathians and 61% in the Alps. Most of the dead germinants and decayed beechnuts were infested by fungi. The average number of fungal colonies per one sample in the Carpathians was significantly higher after mast year than one year before, while the differences between the Alps and Carpathians after mast years were statistically not significant. Fungi have been isolated from practically all dead beechnuts and dead germinants. The number of beechnuts per seed trap, the number of germinants around it and the relative number of fungal colonies obtained from plastic boxes placed in the same sample plot were not significantly correlated. The mortality of germinants continued throughout the spring; the number of life germinants in the middle of May amounted to 0.87% of the initial number of beechnuts in the Carpathians and only 0.28% in the Alps. High rates of beechnut and germinant mortality could probably offset the huge reproductive effort of European beech in old-growth stands and limit the possibility to attain absolute dominance by that species. However, our hypothesis that the build-up of fungal pathogens on the forest floor old-growth stands is able to stop the regeneration of beech still needs to be tested using larger data sets.
This paper focuses on the issue related to the response of beech leaves to the opening of stand canopy resulting from a shelterwood cut of various intensity. Four research plots each with a different stand density provided different conditions for the development of foliage. The research was conducted on dominant, codominant and subdominant sample trees representing the mean stand diameter of all plots. The data were compared for the upper, middle and lower layer of tree crowns (each equals to one third of crown length). As for dominant and codominant trees, mean leaf area showed a tendency to increase towards the lower crown layer. As for subdominant trees, relation between the location of leaves in the crown and leaf area was similar to dominant and codominant trees but this trend was observed only on the plot most open. Only in the case of codominant trees the leaf area was decreasing with a decreasing stand density. Greater stand opening results in a proportionally smaller leaf area. Growing conditions for subdominant tree leaves were completely different when compared to conditions for upper tree classes. On the plots with harvest cutting we observed that a decreasing stand density resulted in a general increase of leaf size. The only exception to the rule was the control plot where the parameters recorded were higher and inconsistent with the above described trend.
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