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Carbon sequestration by forest ecosystems in canging climate.
Hlaváčková, Lucie ; Lhotáková, Zuzana (advisor) ; Urban, Otmar (referee)
The global carbon cycle is in the focus of the scientists' interest, because understanding carbon sinks and their relationships can show the solutions of problems related with increasing CO2 concentration in the atmosphere in the future. I focused on the role of forests ecosystems in this carbon cycle. All forests cover almost one third of the Earth's land area. By photosynthesis they bind big part of atmospheric carbon to their biomass. Sink strength of forest can differ according to the type of biome, forest stand age and actual climatic conditions. Forest biomes can be generally divided according to the latitude to three groups: tropical forest biomes, temperate forests and boreal forests. The size of carbon stock decreases in this order. Other parameters, such as net primary production and respiration differ in dependence on the particular ecosystem. Tropical rain forests represent great carbon stock, but their deforestation causes massive C emissions back to the atmosphere. Boreal forests aren't considered as important carbon sink, but they influence local climate. Some speculations can also appear about the old forests. It is possible to find authors, who claims, that old forests are no more carbon sinks, so that their carbon balance is neutral. Many surveys prove that they bind less carbon...
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Mesophyll CO2 conductance in consequence with the leaf anatomy and environmental factors.
Malcová, Kateřina ; Lhotáková, Zuzana (advisor) ; Nátr, Lubomír (referee)
The CO2 diffusion pathway from the atmosphere surrounding the leaf to the chloroplast stroma is composed of several parts, where each part poses certain resistance to the CO2 flux. The CO2 diffusion from the sub-stomatal cavities to the stroma is limited due to mesophyll conductance (gm), which includes CO2 movement in gas, liquid and lipid phases. The mesophyll conductance is influenced by factors that are both internal (e.g. leaf anatomy and leaf age) and external (e.g. irradiance, temperature). Internal factors exhibit rather long-term responses of gm, while external factors are involved in short-term changes. For these rapid changes are probably responsible aquaporins. gm significantly influences the rate of net photosynthesis, almost in the same range as a stomatal conductance does. The limitation of photosynthesis given by mesophyll conductance is not fixed and varies among species and plant functional groups. Due to continual increase of CO2 concentration in the atmosphere, variability in gm can lead to enhanced competitive potencial of some plant species.
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How and why we can estimate atmospheric CO2 concentration from stomatal density?
Horská, Jana ; Lhotáková, Zuzana (advisor) ; Kutík, Jaromír (referee)
The atmospheric carbon dioxide concentration have always been fluctuating. In the past [CO2] did not ever increase as quickly as in the last 200 years and apparently human activities such as fosil fuel burnig conribute significantly to this increase. Changes in stomatal frequency as a reaction on changes in [CO2] were observed on several species of living plants. It leads to investigation of stomatal fequency of herbarium samples and fossil plants. These estimates of stomatal frequency were consequently used to estimate levels of atmospheric [CO2] in the past. This study describes behavior of stomata in variable [CO2] and summarizes influence of environmental factors on stomatal patterning. The differences in responses between groups of plants of different evolutionary origin are considered. The advantages and disadvantages of selected stomatal parameters are discussed considering their suitability as tools for [CO2] estimate in the past.
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Energy Assessment
Březina, Jan ; Maurerová, Lenka (referee) ; Horák, Petr (advisor)
The first part of the final thesis is focused on the use of thermovision for diagnosing defects and failures in building industry. Documented history, physical principles and conditions for the measuring of thermographic camera are described in this part. Thermal images of the object described below were used for demonstrating the defects. The second part is dedicated to the elaborated energy assessment for a nine-storey slab block building. In total, there are five energy economic measures developed for the building. Three of those are of structural character and two of those are for building equipment. There are two variants designed based on the measures, one of which is recommended and evalu-ated. The final section is focused on the measurement of slab block building indoor environment (CO2, air temperature, relative humidity, dew point) and its assessment in concern with the current legislation.
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Energetic evaluation of civil buildings
Pliska, Roman ; Adam, Pavel (referee) ; Horák, Petr (advisor)
The first section of this thesis describes possible energy savings in family houses. Subsequently, possible energy savings are applied to, and a system revision is presented for, an office building, along with a calculation of the return on investment for the described variant based on notice 480/2012 Sb. The final section focuses on the measurement of the indoor environment at an administrative building (CO2, air temperature, relative humidity) and their assessment according to the current legislation.
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Electronic instrument for environment monitoring during plants growing
Žák, Jaromír ; Kuchta, Radek (referee) ; Hubálek, Jaromír (advisor)
The main goal of this project is to make electronic instrument for monitoring environment during plants growing for Mendel University of Agriculture and Forestry in Brno. The new device will replace current analog recorder of temperature and humidity. New device will be extended by measuring atmospheric pressure, illumination and CO2 concentration. Main advantage of electronic measuring is better lucidity of gained values. New concept allows easier comparison new values with earlier measured data.
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The dynamics of non-structural saccharides accumulation and Rubisco activity under the elevated carbon dioxide concentration and sink manipulation at beech
Uhrová, Lucie ; Vítová, Eva (referee) ; Hrstka, Miroslav (advisor)
This diploma thesis deals with dynamic of accumulation of non-structural carbohydrates and activity of Rubisco enzyme at elevated concentration of CO2 on beech (Fagus sylvatica L.). Three years old seedlings of beech were cultivated in minisphere with ambient (385 µmol•mol-1, variant A), and with elevated concentration CO2 (700 µmol•mol-1, variant E) for four months. In every variant the first half of plants was fertilized by nitrogen (variant N+) and the second half was control (variant N-). Plants used for experiment were at first adapted for darkness for 12 hours. Subsequently tested leaves were cut off, leafstalk including short segment of branch (approximately 1 cm) was inserted into 0.7 M solution of sucrose (variant S) or water (variant V) and exposed to radiation 200 mol•m-2•s-1 for 0, 30, 60, 120, 180 minutes. Then leaf area and fresh mass of leaf blade were established, samples were fixed in liquid nitrogen and stored in deep freezer to analysis in –70 °C. Rubisco content was determined by SDS-PAGE method, Rubisco activity spectrofotometrically and content of non-structural carbohydrates by anthrone method and HPLC method. Rubisco content was significantly lower in the N- variant than in N+ variant. Rubisco content was also significantly lower in E than in A variant, which is an evidence of down-regulation. Rubisco activity is moderately stimulated at E variant with time, but differences between variant A and E are not statistically significant. Influence of sucrose feeding to Rubisco activity was not proved. Significant differences were detected by anthrone method in non-structural carbohydrates content between variants S and V, but not between variants A and E. Statistically significant increase of sucrose content with time was detected by HPLC method at variant AS, but not at variant ES.
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Interactive effects of elevated CO2 concentration, drought, and nitrogen nutrition on yield and grain quality of spring barley and winter wheat
Surá, Kateřina ; Rajsnerová, Petra ; Veselá, Barbora ; Klem, Karel
The interactive effects of elevated CO2 concentration (EC; 700 μmol mol–1), drought stress, UV exclusion, and nitrogen nutrition were studied in open-top chambers located in the Bohemian–Moravian highlands (24 in total). Above-ground biomass at the time of harvest, grain yield, and grain quality parameters were studied in winter wheat (variety Bohemia) and spring barley (variety Bojos). The results showed that elevation of CO2 concentrations increased above-ground biomass and grain yield. Higher levels of nitrogen increased the stimulatory effect of EC on above-ground biomass and grain yield. In addition, UV exclusion stimulated the effect of EC. EC generally led to increased rates of photosynthesis and assimilate formation. Increased storage of starch in the grain led to an unbalanced proportion of proteins and a decrease in their relative content in grain. Similarly to grain yield and above-ground biomass, the decrease in protein content under EC was also more pronounced under UV exclusion. EC led also to reduction of other quality parameters, such as the Zeleny sedimentation test. This effect is more pronounced when nitrogen is not a limiting factor as well as under the effect of drought. The stronger effect under drought stress is probably due to increased water use efficiency.
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