National Repository of Grey Literature 81 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Leaf physiological and optical properties in relation to the Phytophtora × alni infection of black alder (Alnus glutinosa)
Oramová, Viktorie ; Lhotáková, Zuzana (advisor) ; Tomášková, Ivana (referee)
A current problem is the infestation of the black alder (Alnus glutinosa) by the pathogen P. × alni, which causes the loss of alder stands and disrupts riparian ecosystems. The spread of the 'phytophthora disease' occurs through water, the host is infected through the root system and the pathogen attacks the conductive tissues. As a result of the disease, the tree gradually loses its root system, lesions appear on the trunk, defoliation occurs and the individual inevitably dies. The only solution to the situation is preventive measures to prevent further spread by careful removal of infected alder trees. The aim of this paper is to discuss the relationship between black alder and P. × alni in the context of the physiological changes that occur in the foliage of the infested individual. Leaf functional traits, chlorophyll fluorescence and optical properties of black alder exposed to P. × alni (inoculation into soil or confirmed occurrence of the pathogen in natural conditions) were measured using non-invasive methods. The results of the chamber experiments suggest that the mean values of the measured parameters do not change significantly in the initial stages of infection, but there is a widening of the variance of the values in infected individuals. We tested whether the genetic origin of the...
Drought stress response of European beech seedlings monitored using physiological and optical indicators.
Červenka, Ondřej ; Lhotáková, Zuzana (advisor) ; Gebauer, Roman (referee)
One of the manifestations of global climate change is an increase in extreme temperatures and drought waves, while forecasts of future development indicate deepening negative impacts. The effect of these abiotic stress factors is reflected in the physiological state of the vegetation. It is therefore necessary to find suitable stress indicators that will help detect the worsening of physiological state of vegetation in time series. Indicators can be detected not only by physiological methods, but also optical ones, for further use of vegetation monitoring by remote sensing methods. Forest beech (Fagus sylvatica L.) is a native tree in our context, currently widely used in forestry for planting more species-varied communities of trees that are more resistant to the effects of climate change. The aim of the thesis was to study the responses of beech to drought stress using physiological and optical indicators. Beech seedlings (planting material from the nursery) were placed in containers in the experimental greenhouse for two experimental seasons, water supply was mediated by drip irrigation. The experimental material was divided into three groups with graded irrigation (control, moderate drought and drought). The watering regime consisted of three periods of drought and recovery phases with uniform,...
Physiological status of young silver fir on stands with different microclimate using biochemical, and optical needle traits.
Kabilková, Eva ; Lhotáková, Zuzana (advisor) ; Pokorný, Radek (referee)
Silver fir (Abies alba Mill.) is a candidate tree species in the process of forest transformation especially of spruce monoculture stands (Picea Abies (L.) H. Karst.), thanks to its better growth characteristics in conditions of mild drought. However, fir, as a very shade tolerant tree, may be more susceptible to various abiotic stressors in more open forest canopies, and therefore it is necessary to study its ecological requirements in connection with the most effective possible application in forestry. In this thesis, the physiological state of young fir stands affected by different light microclimatic conditions, which were represented by different types of forest regeneration, was studied. Specifically, it is shelter-wood cut, which represents the likely highest degree of shading by mature trees, then natural regeneration under sparse canopy, gap cut and small clear cut, which represent a moderate degree of shading by mature trees, and last but not least, clear cut, which represents the lowest degree of shading. Physiological status was evaluated using biochemical and optical properties of the needles, and additional microclimatic conditions of the habitats, namely temperature and soil moisture, were also evaluated. Our results showed that the used biochemical and optical properties of the...
Response to abiotic stress in plants growing in green façades of temperate urban environment
Hrochová, Růžena ; Lhotáková, Zuzana (advisor) ; Havelková, Lenka (referee)
With increasing urbanization the temperature of cities is increasing and an effect of urban heat island arises. Vegetation, particularly vertical greenery systems: facades and walls, is mitigating urban heat island and reducing temperature. The aim of this work was to define these systems, their effects on the urban microclimate, to create an overview of the most used plants for greenery systems and to summarize their reactions to abiotic stresses of cities in a temperate region. Mediterranean studies were used in this work due to the scarcity of temperate climate research, which results could become valuable with climate change. Selecting proper vegetation can be done using habitat template, plants that are acclimated or adapted to the urban environment. Plants affect the urban microclimate through shading and transpirational cooling, which ideally contribute to reducing the heat island effect with optimal irrigation. Stressors followed in this work were drought, high temperature and irradiance, air pollution and salinity. To all these stressors plants reacted with limiting physiological functions and reducing growth. The common reaction was a decrease photosynthesis rate and chlorophyll content. Ractions of plants of vertical greenery systems to different stressors and their combinations are...
Thermal imaging as a tool for evaluation of plant's cooling effect in green façades
Nohová, Michaela ; Lhotáková, Zuzana (advisor) ; Schwarzerová, Kateřina (referee)
Urbanisation and global warming are gaining momentum, and with it the need to improve the thermal comfort of urban citizens is growing. Due to the geometry of the city and the thermal properties of the materials from which the city consists, the so-called urban heat island effect occurs, which causes the temperature in city centres to be higher than in rural areas. One possible way to mitigate the urban heat island effect is to incorporate vegetation into the urban infrastructure. Green architecture is designed to do just that, and in this thesis I specifically focus on green facades and their cooling effect. Since green facades are usually large areas of green surface, this thesis focuses on thermal imaging and its use to measure the cooling rate of buildings and ambient air by green facades. It is the use of thermal cameras that is characterized by the ability to image large areas and record their temperature in real time, making thermal cameras an ideal tool for green facade research. As this topic is very specific and not yet so widespread in the literature, I discuss thermography from several perspectives in the context of its use for research on plant physiological parameters, and I also discuss the various methods and pitfalls of working with thermal image data. Key words: abiotic stress,...
Autumn leaf senescence in temperate and boreal woody species under changing climate
Kosová, Barbora ; Lhotáková, Zuzana (advisor) ; Konrádová, Hana (referee)
Autumn senescence of the foliage of deciduous trees of temperate and boreal zones is an annually recurring phenological phenomenon, which is part of the adaptation to life in the temperate and boreal zones with periods of frost and restriction of solar radiation. During foliar senescence, photosynthetic pigments decompose, mineral nutrients are remobilized and foliage falls off. The timing of foliage senescence in boreal and temperate deciduous trees is controlled by external and internal factors. The biggest role in the timing of senescence is played by photoperiod and temperature, which gradually decrease by he end of the growing season. The temperature is increasing due to global warming, thus affecting the length of the growing season and the sequestration of carbon into forest stands. Other factors (such as water availability) are also affected by climate change. The above-mentioned factors affect the trees of boreal and temperate forests to varying degrees, and it is, therefore, important to address them in order to be able to estimate the future development of foliage senescence and carbon sequestration in temperate and boreal forests.
Specifics of plant mineral nutrition on serpentine soils
Škopová, Lucie ; Tylová, Edita (advisor) ; Lhotáková, Zuzana (referee)
Serpentine is a metamorphosed ultramafic rock on which a substrate with specific combinations of properties responsible for creating the typical inhospitable conditions for plant life is formed. The characteristic chemical composition of serpentine soils consists of a low ratio of Ca:Mg ions, low content of biogenic elements (P, K, N) and a high concentration of heavy metals (Co, Cr, Ni). Abiotic factors such as rocky surface, shallow soil and lack of water also hinder the life of local plant. The aim of this bachelor thesis was to summarize the complex of characteristic serpentine phenomenon that in many ways create stress conditions for plants growth. Thanks to this specificity, the serpentine areas are characterised by a specific flora and vegetation with a number of endemics. This work focuses on the specific mineral nutrition of plants and summarizes the knowledge on the mechanisms of adaptation of plants growing on serpentine substrates. I focused mainly on the typical low Ca:Mg ion ratio in serpentine soil and described the functions of these elements in plants and the stress effect of excess Mg. Throughout this work, I also address the mechanisms of uptake and transport of serpentine-relevant nutrients in the plants identified so far. In conclusion, I discuss ability of plants to survive in...
Effect of artificial light at night on ecophysiological functions of plants
Ležal, Lukáš ; Konrádová, Hana (advisor) ; Lhotáková, Zuzana (referee)
Artificial light at night, as a significant source of anthropogenic pollution, has long been overlooked, both among the general public and in the scientific community as well as at the legislature level. Steps to reduce the negative impacts of artificial light at night have been taken late and to an insufficient extent, and it was the low general awareness that was one of the motivations for the bachelor thesis on this topic. Plants are a group of organisms that receive less attention than, for example, humans, although they far exceed them in ecological importance. Artificial light at night has the potential to alter the composition of plant communities and the food webs that are linked to them, of which humans are at the top. This is done by shifting plant phenological phases, disrupting the natural perception of day and night, modifying growth patterns and morphological characteristics, increasing irradiance stress or reducing the efficiency of photosynthesis. It is through a comprehensive knowledge of the interaction of plants with artificial light at night that society can effectively protect nature and introduce the necessary new standards and technologies to ensure sustainable development.
Assessment of drought response in local Scots pine ecotypes using anatomical, biochemical, and fluorescence stress markers.
Štěpánová, Kristýna ; Lhotáková, Zuzana (advisor) ; Stejskal, Jan (referee)
Global climate change and associated global warming is already a problem for temperate forest ecosystems and will continue to exacerbate the problem in the coming decades. Many species will have to adapt to a multifactorial combination of stresses, with increases in average air temperature, frequency and intensity of precipitation increasing drought episodes and drought-affected areas will enlarge. It is necessary to find ways to help the landscape cope with these intensifying phenomena. The possibility of planting suitable tree species that can manage water efficiently and survive even in periods of intense water scarcity is an option. The drought tolerance of trees is related to their phenotypic plasticity and ecotypic differentiation. Scots pine (Pinus sylvestris L.) is characterised by modest ecological demands on the environment and climate of the habitat, is phenotypically plastic and relatively drought resistant. The objectives of this study were 1) to evaluate and compare the response of different Scots pine ecotypes to drought stress due to reduced water availability using anatomical, biochemical, and fluorescence indicators of physiological status, and 2) to determine the biochemical phenotype of selected genotypes within a local Scots pine ecotype in a seed orchard in terms of...
Experimental cultivation systems in root system research
Střelec, Petr ; Soukup, Aleš (advisor) ; Lhotáková, Zuzana (referee)
The growing awareness of plant root importance has contributed to the continuous development of cultivation methods that facilitate more efficient and effective root research. Due to their sessile nature, plants rely extensively on roots for water and ion absorption (Meister et al., 2014). As a result, plant roots must adjust to an array of unfavorable conditions such as salinity, drought, and high temperatures. To better understand root response and promote agricultural development, researchers simulate various stressors in controlled conditions. More recently developed transparent soils and soilless cultures aim to overcome the limitations of traditional soil cultivation, which include imprecise variable control, heterogeneous conditions, and destructive root sampling (Gregory et al., 2009). When planning an experiment, it is crucial to select an appropriate cultivation method to ensure success. The aim of this thesis is to provide a comprehensive overview of the benefits and limitations of commonly used cultivations techniques in plant stress research. Transparent soil reliably mimics the mechanical properties of soil whilst allowing for easy root access and use of numerous visualization techniques. On the other hand, it still maintains the need for a larger cultivation area just like soil. The...

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1 Lhotáková, Z.
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