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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...
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REMOTE SENSING-BASED ANALYSIS OF MULTISPECTRAL INDICES
Janoušek, Jiří ; Kačmařík,, Michal (referee) ; Nedělník,, Jan (referee) ; Marcoň, Petr (advisor)
The thesis discusses various perspectives on the analysis of multispectral images, emphasizing in particular the technique’s potential in remote sensing of the Earth. Within multispectral imaging, the author has explored diverse methods for scanning plants to examine the impact exerted by the invididual electromagnetic spectrum components on the reflectivity of the investigated vegetation. Regarding the relevant vegetation indices, one of the main activities lay in comparing the approaches employed to compute the indices from applicable multispectral images. To deliver general data on the state of the plants being grown, the research involved designing and structuring relevant indicators that enabled the author to correlate the multispectral indices. In this context, the final sections of the thesis present the spectral maps acquired from the multispectral camera images and expose the analyses centered on the resulting index values, the aim being to help determine reliably the optimum harvest time in agricultural crops. The output of the project outlined within the thesis is then embodied in novel linear regression models that facilitate defining the optimum such a time. Importantly, by extension, the author also proposes a compact methodology that covers the individual phases and steps between the vegetation imaging the crops and finding the optimum harvest time.
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Využití pozemní senzorové sítě pro kalibraci družicových dat dálkového průzkumu
Doubrava, Pavel ; Batrlová, Iva ; Kvapil, Jiří ; Seidlová, Jana
Dálkový průzkum Země je disciplína založená na fyzikálních principech. Naměřená data jsou zpracovávána matematicko-fyzikálními a matematickými metodami. Základním fyzikálním jevem, na kterém je dálkový průzkum založen, je interakce elektromagnetického záření se zkoumaným objektem. Informace o tom, jak probíhá tato interakce, nám udává energie, kterou zaznamenává detektor v přesně vymezených intervalech vlnových délek v daném prostorovém úhlu. Takto definovaná interakce je výchozí pro určování hledaných vlastností daných objektů. Každý objekt na zemském povrchu má vliv na naměřené hodnoty energie, a to jak v čase, tak v prostoru. Proto je nutné, aby tato energie byla měřena prostřednictvím kvantitativních fyzikálních veličin.
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Detection of bark beetle attack of Norway spruce using spectral and biophysical data at different hierarchical levels
Vesecká, Martina ; Albrechtová, Jana (advisor) ; Tomášková, Ivana (referee)
There was created an overview of key aspects for a correct understanding of the dynamics between bark beetle and Norway spruce, especially the way of life of the beetle and the time course of its life cycles. It is absolutely essential to understand this interaction for a timely and effective solution to the bark beetle calamity. Furthermore, the mutual interaction of beetle and tree is discussed in detail in the text. Great emphasis is placed on the description of the spruce's defense mechanisms and the consequences of the attack. In particular, biophysical changes in the needles, which cause a change in the spectral behaviour of the leaves and thus the entire forest stand. Using sensor capable of measuring the reflectance of surfaces, it is possible to detect a bark beetle-infested tree much earlier than changes in the needles could be detected by the naked eye and remove it while it is still colonized by the beetle and not spreading further into surrounding trees. This is key to managing not only the current bark beetle calamity. An overview of case studies is given in the thesis, where the use of spectral methods at different hierarchical levels was applied and satisfactory accuracy in the identification of early infested trees was achieved. Key words: Norway spruce, bark beetle, bark beetle...
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Alpine glaciers retreat after little ice age and its relation to climate changes
Dutková, Alena ; Sládek, Ivan (advisor) ; Zelenka, Přemysl (referee)
This thesis deals with climatic changes and its influence on mountain glaciers in Alps since the little ice age to present. Knowledge published in domestic and foreign literature is applied to the example of Morteratsch glacier in swiss Alps and high elevation meteorological station Sonnblick in austrian Alps. Alpine mountain range is one of the most researched and the longest populated mountain ranges in the world. For this reasons we have for use long time period of meteorological and glaciological datasets.
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