|
|
The impact of UV radiation on activity and content of Rubisco enzyme in beech
Cigánková, Michaela ; Urban,, Otmar (referee) ; Hrstka, Miroslav (advisor)
This bachelor thesis deals with the influence of UV radiation on content and activity of Rubisco enzyme in leaves of European beech (Fagus sylvatica). Plants were cultivated in ambient (UV), lower (UV-) and higher (UV+) UV-B radiation both at ambient (AC) and elevated (EC = 700 micromol mol-1) CO2 concentrations. Leaves sampling was done four times during the growth season, in the second part of July, at the beginning and in the end of August and in the middle of September. Rubisco activity was assayed spectrophotometrically, the content of Rubisco was determined by SDS-PAGE method and quantified by computer densitometry. The results confirmed a reduction of Rubisco content and down-regulation on Rubisco level at elevated CO2 concentration. With the exception of September sampling, the content of Rubisco was lower in UV+ at ambient concentration of CO2. The same was not demonstrated at elevated CO2 conditions. Hypothesis that UV-B radiation changes a ratio of large to small subunit of Rubisco was confirmed. The influence of UV-B radiation on Rubisco activity was not proved.
|
|
|
Vliv chemické modifikace na vybrané vlastnosti dřevěné pružiny
Novák, Filip
This thesis focuses on the influence of chemical modification on a wooden spring.The spring was made of beech wood (Fagus sylvatica, L.). Bending ratio was chosen 1:4 thickness to radius. The effectiveness of the chemical modification with acetic anhydride was measured by weight percentage gain (WPG). Acetylation was made with 18 % WPG (at full acetylation 25 % WPG was observed damage of bent wood mostly by compression stress). Chosen spring properties was evaluated in four moisture states (dry, in condition of 65 %, 85 % and 99 % relative humidity and temperature 20 °C). Influence of acetylation on mechanical properties was proven. In wet condition acetylated samples proved higher shear modulus of elasticity a higher rigidity of spring. In dry condition acetylated samples proved lower shear modulus of elasticity a lower rigidity of spring. Influence of acetylation on dimension stability was proven. Acetylated samples proved reduction of equilibrium moisture content (46-56 %) in comparison to reference samples. Acetylated samples proved swelling reduction in radial direction (41-56 %) and in tengential direction (46-59 %). More regular swelling (ratio of radial and rangential) was observed at acetylated samples. Influence of acetylation on shape stability was proven. Shape stability of acetylated spring was evaluated by change in diameter of spring in different moisture states. Wet conditions caused enlargement of acetylated spring diameter (5-16 %) and of reference spring diameter (10-40 %). Reduction of shape changes was observed (57-75 %).
|
|
|
Výskyt a hodnocení zdravotního stavu hlavních edifikátorů lesních porostů v oblasti Přírodní lesní oblasti č.16 Českomoravská vrchovina
Krajíčková, Dominika
In 2021, the representation of European beech (Fagus sylvatica) in the Czech Republic was 9.3 %, of maples 1.6 % and oaks 7.6 %. These values are slowly increasing, and the representation of European beech has increased by 3.3 % of the total area of arable land over the last five years (Zelená zpráva 2021). This work discusses the life manifestations of European beech (Fagus sylvatica), Norway maple (Acer platanoides), Sycamore maple (Acer pseudoplatanus) and Pedunculate oak (Quercus robur) in selected small protected areas in the Natural Forest Area No. 16 of the Czech-Moravian Highlands. The aim of this work is to evaluate the life manifestations of the above-mentioned tree species. Three small protected areas were selected, of which two localities are located in the 5th forest vegetation tier and one partially in the 5th and 4th forest vegetation tier, and endometrial measurements were performed here. The result was a comparison of the obtained data between individual sets of forest types and individual tree species on the set of forest types 5J. The diameter of the trunk and the height of the beech crown deployment were lower at 5K. The Norway maple reached smaller thicknesses at 5J compared to the other trees, on the contrary, the Sycamore maple and Pedunculate oak reached greater heights.
|
|
|
Vliv tepelné a chemické modifikace na sorpční, difuzní a hygroexpazní vlastnosti dřeva
Imramovský, Pavel
This thesis dealed with the influence of heat and chemical modification on sorption, diffusion and hygroexpansion properties of wood. To this aim, a thermal modification of European beechwood was carried out at temperatures (180 °C, 200 °C, 220 °C) in the special modified chamber of Katres. Furthermore, chemical modification was required on individual samples using acetic acid anhydride. The individual samples had to be sliced in radial and tangential directions using microtoma. A dynamic vapour sorption (DVS) device was used to determine the sorption and diffuse properties of all these beech slices as well as the reference unmodified sample. In addition, dynamic swelling was determined for all groups studied in radial and tangential directions. In order to determine the rate of swelling, sample sizes were measured using a scaler in specified directions before and after the 24-hour period in the water. The results indicated that both heat- and chemically-treated beechwood scored better against moisture than reference untreated samples. The diffusion coefficient in the radial direction was also higher than in the tangential direction, which corresponds to the professional literature. The results indicate that heat- and chemically-treated beechwood resisted better moisture than the reference untreated samples. Within swelling, direction plays a large role, as measurements in the tangential direction are nearly twice as high as the radial. The possibilities of using modified wood in construction as well as from the perspective of the researched characteristic were considered. The statistics were performed in the ANOVA program.
|
|
|
Využití potenciálu přirozené a kombinované obnovy na Lesní správě Nasavrky (Lesy České republiky s.p.)
Zemanová, Anna
The diploma thesis dealt with the topic of the vegetation decline of the Norway spruce and its following regeneration in the Lichnice district, Nasavrky Forest Administration. From the results obtained from the forest economic records, it was found that the beginning of spruce decline was detected in 2018. The highest reported volume of random logging was reported in 2020 (46 405.92 m3). The largest reported clearing was also in 2020, at 53.69 hectares. The most common tree species in natural regeneration and artificial regeneration was Norway spruce, but its share is gradually decreasing year by year, to the benefit of a greater diversity of tree species on the range. Next, an experiment was conducted with the seedlings of the forest tree species that were collected and replanted as an underplanting in spruce stand 326A08. The mortality of the three study areas was evaluated here. The best results were achieved by white fir seedlings, where minimal mortality was found, on the other hand, the worst results were achieved by summer oak seedlings, where mortality was almost the majority.
|
|
|
Stav a potenciál přirozené obnovy po kalamitě na revíru Polana, LS Jablunkov
Dyrčík, Vojtěch
The aim of the presented thesis was to evaluate the status and potential of natural regeneration in relation to the condition of surviving individuals of the parent stand after a bark beetle calamity. The locality of interest was the Polana forest district, located in the territory of the Jablunkov forest administration. Five representative stands were selected for the field survey, where after the death of the spruce stand component, there remained in the upper stage individuals of the parent stand, mostly beech (Fagus sylvatica L.). As the number of beech (Fagus sylvatica L.) individuals in the parent stand increased, so did the frequency of rejuvenation of this tree species. In places where there was less beech (Fagus sylvatica L.), spruce (Picea abies (L.) Karst) and white birch (Betula pendula Roth) became more prominent. The most abundant species in the parent stand were beech (Fagus sylvatica L.), sycamore (Acer pseudoplatanus L.) and larch (Larix decidua Mill). A relationship between the rejuvenation of beech (Fagus sylvatica L.) and the condition of the parent stand was also found in the area where the regeneration inventory was repeated. Here, the natural regeneration of Norway spruce (Picea abies (L.) Karst) was more pronounced,as well. In contrast to beech (Fagus sylvatica L.), its abundance in the regeneration decreased after two years.The areas of interest can be considered as restored to 94 % of the total area, of which 77 % was created by natural regeneration alone and 17 % by combined regeneration. In 6 % of the area, rejuvenation gaps need to be filled.
|
|
|
Morfologické změny a změny v produkci biomasy u krytokořenných semenáčků buku lesního (Fagus sylvatica L.) po výsevu naklíčených bukvic
Skuhrová, Eliška
The diploma thesis deals with the influence of different conditions and sprouts damage during sowing of germinated beechnuts on emergence, biomass production and morphological parameters of containerized planting stock of European beech. According to the condition of the sprouts, the beech seedlings were sorted into six variants (small white sprout, large brown sprout, broken sprout, two sprouts, abnormal germination) and then sown to container. To determine the impact of germinated beechnuts, they were gradually sown into the container after different length of storage in the cooler at an average temperature of +0.7 °C. According to the results, it follows that the seedlings grown from beechnuts with an undamaged small white sprout had a significantly higher emergence rate than the seedlings that were grown from beechnuts that were sown ungerminating or whose sprouts were damaged during sowing. The type and length of the beech sprout has also an effect on the morphological parameters, especially on the shape of root collar of the seedlings. No disturbance of the architecture of the root system (root collar) was recorded in the seedlings that emerged from unsprouted beechnuts or the beechnuts with broken sprouts. On the contrary, significant deformations of the root system were recorded in the case of seedlings grown from sprouted beechnuts with small white sprout, large brown sprout or two sprouts. It can therefore be stated as a rule that the smaller sprout the beechnuts will have at sowing, the smaller the risk of deformation of the root system (root collar). Furthermore, it was found that the storage of beechnuts in a cooler does not have a negative effect on the subsequent germinations of the plants. A significant effect of the storage time of beechnuts on the morphological parameters of the seedlings was not recorded. However, it follows from the research that the sowing of beechnut should be carried out in time, so that the plants create the most optimal parameters in the growing season. Thanks to these procedures, it will fulfil the conditions of standardized planting material given by the standard ČSN 48 2115 (2012).
|
|
|
Možnosti výsadby prostokořenného sadebního materiálu v zimním období
Vacková, Jana
The goal of this thesis is to elaborate the possibilities of winter time planting of bare rooted planting material. Because of this were there planted two bathces of plants on the planting area. One in winter time, the other in spring. With both the planting batches there was used the same planting material. There were planted two wood plants – spruce and beech, both in bare rooted and root covered variante. During the groth there happend two measurings. The control one in June, the final one at the end of the vegetation period. The final measuring was made on 100 subjects from each variante. The lower amount was tested only by the root covered spruece due to high losses. By each subject there were mesured these conditions: the height ot hte above ground plant parts in the time of planting and the difference at the time of last measuring, the diametr of the root collar, the lenght and width of the assimilation aparatus. There were also evidated conditions like the color tone of leves, the type of damage, multiplicity of the trunk and losses. Results showed that it is much better to do the planting of bare rooted spruece in spring time. The bare rooted beech is different case – here is absolutely better the winter planting time option. It shows better results. In addition it was shown that the root covered planting materiál is not optimal for spring planting time.
|
|
|
Factors influencing the distribution of European Beech (Fagus silvatica) on the post mining spoil heap
Vobořilová, Veronika ; Frouz, Jan (advisor) ; Münzbergová, Zuzana (referee)
In this thesis the influence of existing vegetation, the distance from the north border of the spoil heap, animal grazing, terrain bumpiness, and soil pH on the distribution and rooting of European Beech (Fagus sylvatica) at spoil heap Velká podkrušnohorská výsypka (50ř14'09 N, 12ř39'05 E) was examined. To accomplish this, beech seedlings within chosen areas overgrown by spontaneous succession or alder restoration were mapped using GPS. A rooting position on the wave-like terrain was recorded for a proportion of the total number of seedlings. Soil pH was also measured on the wave-like terrain. The majority of seedlings (183) were found at the succession sites; only one seedling was found in the alder restoration site. The GLM analysis proved significantly more seedlings in succession sites compared to alder restoration sites (p = 0.0169) and the negative dependence on distance from the north border of the heap (p < 0.0001). Within the wave-like terrain, 46% of seedlings were growing on the north slopes. In 2009, small seedlings were planted into the fresh restoration site and the adjacent succession site, in both cases inside the fencing and outside of it. The seedlings were growing significantly better in the succession site compared to the restoration site, and they were growing better inside the...
|
|
|
Anatomical study of shade and sun European beech leaf under elevated CO2.
Horská, Jana ; Lhotáková, Zuzana (advisor) ; Urban, Otmar (referee)
The present Master thesis focuses on evalution of CO2 concentration and irradiance on selected leaf anatomical parameters of European Beech (Common Beech) Fagus sylvatica L.. The process of photosynthesis is remarkably determined by numerous extrenal factors, among them by atmoshperic CO2 concentration and irradiance and is closely correlated with leaf anatomical parameters. One of these most important anatomical parameters affecting the net assimilation rate is an internal leaf surface, which corresponds to mesophyll area avialable for gas exhcange. Experimental material of the study was sampled from the leaves of juvenile trees of F. sylvatica planted in 2005 and growing under ambient (390 ppm, AC) and elevated (700 ppm, EC) CO2 concentrations on the experimental site of the Global Change Research Center AS CR at Bílý Kříž in the Beskydy Mountains. Sun and shade leaves were sampled from trees of both CO2 treatments in two seasons 3 years apart (2009 and 2012). To determine leaf anatomical parameters, the stereological methods were applied, which yield unbiased estimation of measured parameters, particularly the Fakir method for internal leaf surface determination. The EC effect was observed on the leaves sampled in 2009 only in the decrease of proportion of intercellular spaces in mesophyll. In...
|
guest ::
