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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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What is the reraction of plant saccharide status to enhanced CO2 concentration in the atmosphere?
Bardoňová, Radka ; Lipavská, Helena (advisor) ; Lhotáková, Zuzana (referee)
During last 200 years, the concentration of carbon dioxide (CO2), one of the most important greenhouse gasses, has significantly increased. It is assumed, that by the end of this century, the concentration of CO2 will be as much as two times higher than nowadays. The changes in atmospheric concentration of CO2 are largely caused by human activity. Both direct and indirect effects of CO2 lead to changes on every level of plant body, from changes in gene expression, through changes in physiology and anatomy, to whole-plant morphology changes. Understanding of these changes and relationships between them is necessary for our conception of future 'greenhouse' world and preparation for the life in it. Growth under elevated CO2 conditions generally leads to increase of the assimilation rate. The increase in the amount of fixed carbon then usually causes an increase in carbon to nitrogen ratio and changes in carbohydrate levels in plants. A common phenomenon related to growth at elevated CO2 concentration is an excessive accumulation of nonstructural carbohydrates in leaves. This accumulation can be associated with down-regulation of photosynthesis. However, changes in carbohydrate levels can occur in other plant parts. This Bachelor thesis is focused mostly on woody species. As perennials with secondary...
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Photosynthetic parameters as secondary selection traits during plant breeding for salt stress tolerance
Hlavatá, Věra ; Kočová, Marie (advisor) ; Lhotáková, Zuzana (referee)
High salt concentration is important abiotic stress factor that negatively affect plant growth and development and finally also their yield. Increase of plant tolerance to this stress factor is thus one of the most important goals in breeding programmes, particularly in areas with saline environment. Various physiological traits have been suggested for the testing of plant tolerance to improved salinity. Photosynthetic parameters play undoubtedly the main role, because of their rapid response to stress conditions. Generally, photosynthetic rate, chlorophyll content and chlorophyll fluorescence belong to the photosynthetic parameters, that are usually recommended for the evaluation of stress tolerance. All of them were also used for study of salt tolerance in crop plants. The advantages of these measurements are rapidity, non-invasive techniques and particularly, the possibility to test wide collection of genotypes during the short period. Although some of the parameters were recommended for the evaluation of stress tolerance, the results are still ambiguous. The aim of this study was to briefly describe the changes of selected photosynthetic parameters of different plant species in consequence of salt stress and assess the usefulness of these parameters for reliable screening for salt tolerance.
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The effect of spoil-mining subtrate with heavy metal contents on leaf physiological status with emphasis on phenolics content.
Kovářová, Monika ; Lhotáková, Zuzana (advisor) ; Soudek, Petr (referee)
5 ABSTRACT Heavy metals abundance in the environment increases via natural and anthropogenic processes, mainly mining and industrial activities. Spoil mine substrates of the Sokolovsko Region characteristic by high heavy metal contents are recultivated by tree planting, e.g. of Scots pine (Pinus sylvestris L.). The diploma thesis is a part of a larger project aimed on interpretation of hyperspectral remote sensing data for monitoring of vegetation physiological state. That is why it is focused on non-specific indicators of stress by heavy metals, which can be detected by foliage spectral analyses. The experimental part of thesis comprises 1) field research on P. sylvestris needles and 2) model pot experiments on tobacco plants. Field research was accomplished in 2009 and 2010 on one control locality and three spoil mine banks localities with different heavy metal soil contents (Hg, As and Cu). Photosynthetic pigments', phenolic compounds'and lignin contents were determined spectrophotometrically. Model pot experiments with tobacco plants (Nicotiana tabacum cv. Samsun) - pilot experiment and experiments 1 and 2 using the spoil mine substrates in 2011 and experiment 3 in 2012 also included treatments with different mercury concentration in irrigation (10 and 15 ppm HgCl2). Gasometric measurements (net...
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Comparative anatomy of genus Lasiocephalus - from tropical mountain forest to páramo
Ježková, Barbora ; Soukup, Aleš (advisor) ; Lhotáková, Zuzana (referee)
South American genus Lasiocephalus colonized high altitudes of the tropical Andes, the so called páramo, from lower elevations of the Andean forest. Páramo is a specific high-altitude environment characterised by pronounced diurnal changes in temperature, growing season over the entire year, low average temperatures, generally high humidity, and intense solar radiation. These specific environmental conditions are reflected by anatomical characters of the species. Given the known phylogeny of the group it was possible to observe anatomical adaptations along steep gradient of environmental conditions from forest to páramo. The hypothesis about adaptive changes that occurred during the colonization of the páramo habitats was confirmed. Observed characteristics were, for example, leaf area and thickness, epidermal cells cuticle and cell wall thickness, epidermal cells lumen height, ratio of palisade and spongy parenchyma, stomatal area, stomata length and width, stomata pore length and sieve elements average area. Results suggest that the anatomy of the plants reflect the environmental conditions of the habitats rather than the species phylogeny.
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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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Development of concept of ecological footprint
Vrbová, Anna ; Albrechtová, Jana (advisor) ; Lhotáková, Zuzana (referee)
The ecological footprint is an indicator that measures the size of the bioproductive land needed to provide resources and disposal of waste from existing technologies.It's an important sign of the sustainability of the population on Earth.As we are currently facing an impending lack of many natural resources,this is an important issue.The biomass we use is created by plants,which play a critical role not only in functioning of the ecosystems,but in the concept of the ecological footprint.Individual types of vegetation differ in their relative contribution the overall ecosystems production and consequently to the calculation of the ecological footprint of various lands.For this reason this work is concerned not only with the concept of the ecological footprint, but also with the services that plants provide.The objective of this work is to compile the current information on the evolution of the concept of the ecological footprint,what preceded its creation,and to focus on the important role of plants in the functioning of ecosystems,allowing for the calculation of the ecological footprint.The evolution of the concept of the ecological footprint is covered in Chapter 1.Chapter 2 deals with ecosystem services,their rating,and the critical role that plants play in them.The calculation of the ecological...
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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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Organic farming and modern plant biology
Fantová, Adéla ; Opatrný, Zdeněk (advisor) ; Lhotáková, Zuzana (referee)
The aim of this thesis is to introduce the concept of organic farming from the point of view of contemporary science in the field of plant biology to secondary school students and their teachers. The first part deals with organic farming, its origins and ideological subtext, further on its advantages and disadvantages are summarized. The second part focuses on biotechnological agriculture which uses breeding methods of genetic engineering. The third part presents possibilities of coexistence and confrontation and comparison of these two approaches used in present and future agriculture. The last part deals with inclusion of this topic into present secondary school education and its significance. It includes analysis of textbooks and curricular documents.
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