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Response of tree rings and NDVI of Central-European conifers to extreme climatic events
Mašek, Jiří ; Treml, Václav (advisor) ; Šilhán, Karel (referee) ; Piermattei, Alma (referee)
Terrestrial ecosystems, mainly forests are important sinks of atmospheric carbon with high year-to-year variability driven by moisture availability. Trees store carbon in various compartments of the biomass, namely in stems, roots, and leaves. In this doctoral thesis, I investigated climate-growth responses of stem biomass (represented by tree rings) and leaf biomass (represented by normalized difference vegetation index; NDVI) of Pinus sylvestris and Picea abies in temperate forests of Czechia. I was interested in (i) general climate-growth responses and specifically, in reactions to drought and (ii) topographical factors influencing these responses at various spatial scales. We demonstrated that climate-growth responses of both species' tree rings in the lowlands revealed a significant positive and negative influence of moisture and temperature, respectively, while in higher elevations the responses were opposite. At a landscape level, the topography of relief modulated responses of Pinus sylvestris tree rings, while at the large-scale level, the geographical position and elevation (temperature gradients) were the main factors for both species. Responses of NDVI were slightly weaker compared to tree rings and did not show the influence of topography at any scale probably because vegetation...
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Natural regeneration of spruce stands in Vysoké Tatry (High Tatras) after large scale disturbation
Michalová, Zuzana ; Weiser, Martin (advisor) ; Wild, Jan (referee)
The observational study on natural regeneration of Norway spruce (Picea abies) was provided during seasons 2010 and 2011 in the windthrow area of High Tatra National Park. The main aim of this master thesis was to describe the distribution pattern in Norway spruce regeneration as well as to estimate the spatial scale, which most preciselly describes the differences in its phenotypic variability. Following step was to determine the relative influence of abiotic and stand factors on the growth characteristics and abundance of spruce seedlings. The Main focus lied on stressing the role of biotic interactions, like intraspecific and interspecific competition, leading to certain discrepancies in the phenotype, as well as in abundance of spruce seedlings.The reponse in variability in spruce traits was recognized at each spatial level. The results showed clear causality between soil moisture and vegetation composition, which both directly modified not only the phenotype of spruce seedlings and plants, but have even influenced their counts on particular stands.
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Fungi associated with tree roots
Charvátová, Markéta ; Baldrian, Petr (advisor) ; Gryndler, Milan (referee)
In contrast to the bulk soil environment, plant roots represent a habitat with higher nutrient availability due to the supply of photosynthesis-derived C-containing compounds. The roots thus support the life of various microorganisms that use such compounds, but the root-associated microbes in the same time may face a limitation in N and P availability. Unlike bacteria, many filamentous fungi are able to transport these compounds from soil and their mycelia thus typically extend into this environment. Ectomycorrhizal fungi are a typical example of this nutrition strategy. Tree roots produce exudates, that differ in thein composition for each species and they can also differ among individuals. It causes a high diversity of root-associated fungi. Soil is also inhabited by parasitic and saprotrophic fungi. Composition and activity of microbial communisies in the rhizosphere differ from the bulk soil. This work points at the differences of the rhizosphere and builk soil, the importance mycorrhizal fungi and it presents an overview of fungal species that have been found on the roots of spruce - Picea abies. Key words: fungi, mycorrhiza, soil, rhizosphere, Picea abies
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Determination of volatile isoprenoids as water stress markers of spruce resistance against bark beetle
Slušná, Michaela ; Kalinová, Blanka (advisor) ; Hoškovec, Michal (referee)
Isoprenoids are important components of conifer resin and represent an important part of constituted defence system against herbivores and pathogens. Drought is one of the most important factors that influences the tree physiology and resitance. Due to decreased turgor of resin canal cells, the water insufficiency affects the pressure of the resin and thereby the ability of trees to physically prevent pathogen or herbivore invasion by effective outpouring of the resin. In addition, drought can also change the resin composition and thus can influence the quality of volatiles emitted by the tree. The Norway spruce, Picea abies, is the predominant species of production forests in moderate climate zone. Bark beetles, Ips typographus, represent the most important pest species of spruce. In general, pioneer bark beetles use host volatiles to orient themselves toward the tree suitable for colonization and in many species host volatiles synergize bark beetle aggregation pheromones. Thus the host volatile composition could affect significantly host colonization. This diploma thesis studied the influence of drought on the production and composition of isoprenoid volatile organic compounds in 80 - 100 years old spruce trees. Using I. typographus antennae as biological detectors, we also studied which resin...
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Structure and function of chloroplasts in selected woody plants grown under increased CO2 concentration
Hlízová, Eliška ; Albrechtová, Jana (advisor) ; Kutík, Jaromír (referee)
The effect of elevated CO2 concentration (EC CO2) on photosynthesis has been observed on many hierarchical levels. There was a significant increase in the rate of photosynthesis of examined trees observed in previous studies thus I hypothesised these changes are accompanied by changes of chloroplast ultrastructure and photosystem content and function and the main aim of this study is to evaluate these adjustments. In this study 13 - 14 years old seedlings of Norway spruce (Picea abies L. Karst.) grown in glass domes with adjustable windows - one with ambient CO2 concentration as a control, the other one with simulated EC CO2 (700 ppm) - during the vegetative season were examined. Pigment content, fluorescence and reflectance indexes, activity of photosystem 1 (PS1) and 2 (PS 2) of isolated chloroplasts, size of cross-sectional area of chloroplast and proportion of stromal to granal thylakoids under EC CO2 treatment were investigated. Although there was a significant increase in the maximum rate of photosynthetic assimilation of trees from EC CO2 (observed by other researchers of our team), decreased chlorophyll and carotenoid content as well as the activity of both photosystems were observed, which is usually atributed to photosynthetic acclimation. As the rate of decrease of photosystem 1 and photosystem 2...
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The role of DSE (Dark Septate Endophytes) in plant communities in forest ecosystem
Lukešová, Tereza
10 Abstract All plants live in symbiosis with fungal endophytes - they can form mutualistic, commensal or parasitic symbioses. Symbiosis of root endophytes, called for their darkly pigmented and septated hyphae dark septate endophytes (DSE), and plants has been often overlooked although its role for plant communities can be very important. Despite their ubiquitous presence in roots of terrestrial and also aquatic plants the influence of DSE on their host plants is still unresolved. Results of previous studies are inconsistent - some reported that DSE have positive effects on their host plant growth and some negative. The main reason for this inconsistency might be their complicated taxonomy and difficult identification of different cryptic species which are morphologically indistinguishable. We were able to complete a unique collection of the most common DSE species, mainly members of the Phialocephala fortinii - Acephala applanata species complex. The collection includes the most common DSE species isolated from roots of forest plant communities. The goal of my thesis was to describe behaviour of DSE in roots of typical forest plants and elucidate their physiological influence on host plants. In vitro resynthesis experiments were used to observe root colonization patterns. Nutrient flow between the plant...
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Soil Respiration of the Spruce Forest during Four Years after the Application of the Different Dolomitic Limestone Dosage
Rosíková, J. ; Dařenová, Eva ; Kučera, A.
The study focuses on an in situ response of soil respiration at 10 °C (R10) of the Norway spruce monoculture to the application of the different dolomitic limestone dosages (0, 2, 3, 4, 6, 9 a 26 t.ha-1) over a period of four years. Soil respiration was measured within the growing seasons 2016 – 2019. Moreover, the pH was determined in the H and Ah horizons during each season. The effect of liming on soil respiration was statistically significant during all the seasons except for 2017. The greatest effect was observed within the first season after liming. In May 2016, R10 in the limed plots increased as much as by 97% compared to the non-limed ones. However, soil respiration did not increase in the direct proportion to the liming intensity. We found out the correlation between soil respiration and the micrometeorological parameters (temperature and moisture) when both low temperature moisture limited soil respiration. Due to the strong soil buffering capacity, the small effect of liming on the soil acidity was observed in the first study season. In the following seasons, the differences in the pH among the plots with the different liming intensity started to increase, which was, however, observed only in the H horizon. The substantial increase in the soil microbial activity accompanied with faster respiration after liming can lead to the increased threat of rapid mineralization and the loss of soil organic matter with all its negative impacts
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Deep learning for tree line ecotone mapping from remote sensing data
Dvořák, Jakub ; Potůčková, Markéta (advisor) ; Lefèvre, Sébastien (referee)
Deep learning is growing in popularity in the remote sensing community, especially as a classification algorithm. First part of this thesis describes deep neural networks commonly used for remote sensing classification and their various applications. Capabilities of selected geospatial software suites in relation to deep models are also discussed in this part. Theoretical findings from the first part of the thesis are validated using two deep convolutional Encoder-Decoder networks - U-Net and its proposed adaptation called KrakonosNet. They are used to perform a sematic segmentation of spruce trees and dwarf pine shrubs in the tree line ecotone of the Krkonoše Mountains, Czechia. A normalised digital surface model is employed for creation of sufficiently large amount of training data, while the classification itself is performed using only optical imagery with very high spatial resolution. Resulting classification is compared to a set of traditional remote sensing classifiers, namely Maximum Likelihood, Random Forest, and a Support Vector Machine. Both U-Net and KrakonosNet significantly outperform the other classifiers on this dataset and will be consequently used in a related research project. Key words deep learning, U-Net, Krkonoše mountains, classification, vegetation mapping, picea abies,...
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Vliv umělé mykorhizace na odrůstání kultur smrku ztepilého
Vlk, Jiří
The diploma thesis deals with the effect of artificial mycorrhization on the growth and on the development of the root system of Picea abies (L.) Karst. cultures. The thesis was conducted at 2 sites under the administration of the Vojenské lesy a statky ČR, s.p., division Lipník nad Bečvou, that were afforested in 2012 and 2013. Every site was divided into 2 parts of the same area. One of the parts was afforested with the use of the mycorrhizal preparation Ectovit and the fertiliser Vápnitý dolomit. The effect of preparations on the above-ground part of trees was evaluated on 210 sample trees at every site. The effect of preparations on roots was evaluated on 10 sample trees. Following parameters were assessed for every sample: the height of the tree; the thickness of root collar; height increments; length of needles; the damage caused by biotic or abiotic factors; number, thickness and length of both horizontal and vertical roots; the number of fine roots; the weight of dry mass of both fine and coarse roots; branching index of fine roots and the specific length of fine roots. Unfortunately, one site had to be omitted from further evaluation of effects on the roots due to the high occurrence of root deformations. The measurement was carried out in June and July 2016. As regards the above-ground part, the research has not proved significant positive effect of preparations. The differences in height increments speak in some cases for, however in some cases against the application of preparations. The lengths of needles were in some years shorter at the sites with preparations and thus may indicate even negative effects of preparations. Regarding root system, a difference was found out only in the case of branching index. No difference was identified for other parameters of the trees on the check and on the test site. Some parameters (e.g. height increments), however, might be considerably influenced by the damage caused by wildlife or by other factors (e.g. heavily stony soil in some parts of the sites). Last but not least, the thesis formulates recommendations regarding the future use of preparations within the company VLS Lipník nad Bečvou.
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Možnosti využití hnojení při zalesňování nelesních půd v PLO 31 Českomoravské mezihoří
Dujka, Petr
An afforestation of agricultural lands in the Czech Republic has a long tradition. In the future, a few thousands of hectares of agricultural lands is considered to be afforested. The aim of this thesis is to research possibilities of fertilisation usage in process of agricultural lands afforestation within Natural forest area (NFA) 31 Českomoravské mezihoří. The research part of the thesis contains results of soil and nutrition analyses applied in Letovice-Kochov research area. The main goal of analyses was to find the impact of fertilisation on chemical soil characteristics, on nutrition of Norway spruce's needles (Picea abies (L.) Karsten), on the development of morphological quantity, and on the health of specimen. All of the characteristics are assessed in the context of climate in 2016. The positive effects of fertilisers were researched despite a low-humid year. The best effects were spotted at fertiliser SilvamixR30. To the results, SilvamixR30 fertilizer could be used in praxis, especially for agricultural lands afforested in named NFA.
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