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Cross-taxon congruence in species diversity in non-forest habitats
Koštíř, Vojtěch ; Sedláček, Ondřej (advisor) ; Tropek, Robert (referee)
Relationships between different groups of organisms are one of the major factors shaping Earth's ecosystems. This thesis analyses correlations in species composition and species richness at different spatial scales. Knowledge of these so-called cross-taxon congruences are crucial for proper nature conservation and management of species-rich localities of non-forest habitats. One of the main aims of the thesis was to find suitable surrogate groups for biodiversity conservation in non-forest habitats. Invertebrates and vascular plants are generally good surrogate groups for biodiversity conservation. For example, ground beetles seem to have good correlations in species richness at large spatial scales. However, their importance deeply declines at small spatial scales. At both scales, the species richness of ants and butterflies positively correlates with general species richness. Vertebrates, on the other hand, appear to be a bad surrogate taxon, except for birds which can be placed into a shopping basket with invertebrates and plants. At small scales, species composition differs with the type of agricultural use at studied localities. Umbrella species can be selected from these specific species communities. Best umbrella species for non-forest habitats are invertebrate herbivores such as butterflies...
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Biodiversity of green roofs
Matoušková, Kateřina ; Sedláček, Ondřej (advisor) ; Šípek, Petr (referee)
Green roofs offer interesting multifunctinaly solutions to many problems at once. In a small area they bring benefits to people and nature. They thermally insulate buildings, improve the local microclimate and reduce the city's heat island efect. Green roofs improve air quality and also help retain water in the landscape. In combination with solar panels and retention tanks, green roofs can contribute to the modern trend of building green - sustainable - buildings. Green roofs can be used for growing food sources and for relaxation as well. Wild plants can spontaneously colonize green roofs and thereby expand their habitats in cities. The plants create habitats for many animals (especially invertebrates) and provide nectar sources to pollinators. Except food habitats, they offer birds habitat for nesting and resting place during their migration. The aim of this thesis was to evaluate the contribution of green roofs to urban biodiversity. At present, howewer, most scientific studies deal with the advantges of green roofs in connection with enviromental protection or the technical side. A small part of the studies examines the biodiversity of green roofs. My goal was to find out which factors influence a biodiversity of green roofs the most and to design an ideal roofs solution with the greatest...
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Effects of grazing on grasslands with the focus on the knowledge from the Czech Republic
Marek, Matouš ; Münzbergová, Zuzana (advisor) ; Sedláček, Ondřej (referee)
This bachelor thesis focuses on the application of grazing management on semi-natural grasslands of Czech Republic. One of the purposes of this thesis is to present the concept of using non-scientific literature and experience of conservation practitioners, the "Evidence based conservation", which serves as an inspiration for this bachelor thesis. This concept acts on the principle of making systematic reviews using a broad spectrum of unpublished sources, including personal observation. This thesis is composed of two parts. The first part is a review of scientifically proven impacts of grazing on biodiversity and its individual parts, primarily the plants. The second part focuses on knowledge and opinions of conservation practitioners, who are interested in grazing management. This thesis presents different ways of grazing management, particular grazing problems and their solutions. It speaks about the importance of communication with the general public, which is an often underestimated factor. In this thesis, the grazing conservation is divided into two fundamental elements, the applicating part and the institutional part, which are here also compared. Another aim of this thesis is to analyse the current condition of grazing management and conservation of semi-natural grassland in Czech Republic...
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Methodological problems of the analyses of insect decline
Chlup, Petr ; Storch, David (advisor) ; Sedláček, Ondřej (referee)
In recent years, several studies reporting a severe decline of insect populations across several continents turned the spotlight on the problem of insect decline. However, the reported declining parameters may vary, and it is necessary to differentiate between declines in biomass, abundance, diversity, or geographical range reduction. This thesis aims to summarize how the conclusions about insect decline are shaped by the methods researchers use, especially by the variables they measure, emphasizing the potential methodological issues and limitations of the various facets of insect decline. Furthermore, we offer a brief digest of the most relevant potential biases and interpretative risks threatening population monitoring surveys. The review also provides concise insight into the state of knowledge on the matter of insect population trends. Keywords: insects, insect decline, insect population trends, methodology, methodological issues
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Polymer carriers for nuclear medicine
Sedláček, Ondřej
In the thesis, we developed and studied a novel polymer delivery system for the DNA-intercalator bearing radioisotope iodine-125. Auger electrons emitting radioisotopes (such as iodine-125 or indium-111) are a potentially effective cancer treatment. Their use as an effective cancer therapy requires that they will be transported within close proximity of DNA, where they induce double-strand breaks leading to the cell death. This type of therapy may be even more beneficial when associated with drug delivery systems. The DNA intercalators proved to be effective carriers for the delivery of Auger electron emitters into DNA. Therefore, the new radioiodinated DNA-intercalating ellipticinium derivatives were synthesized and characterized. These compounds were linked to N-(2-hydroxypropyl) methacrylamide copolymer with narrow molecular weight distribution via acid-sensitive hydrazone linker. The structure of the linker plays a crucial role in the biological effectivity of the delivery system, so it was optimized to be stable at pH 7.4 (representing the pH of blood plasma), whereas in slightly acidic pH in endosomes after the cell internalization, the radioiodine-containing biologically active intercalator is rapidly released from its polymer carrier. The intercalating ability of the active compound was...
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Polymer carriers for nuclear medicine
Sedláček, Ondřej
In the thesis, we developed and studied a novel polymer delivery system for the DNA-intercalator bearing radioisotope iodine-125. Auger electrons emitting radioisotopes (such as iodine-125 or indium-111) are a potentially effective cancer treatment. Their use as an effective cancer therapy requires that they will be transported within close proximity of DNA, where they induce double-strand breaks leading to the cell death. This type of therapy may be even more beneficial when associated with drug delivery systems. The DNA intercalators proved to be effective carriers for the delivery of Auger electron emitters into DNA. Therefore, the new radioiodinated DNA-intercalating ellipticinium derivatives were synthesized and characterized. These compounds were linked to N-(2-hydroxypropyl) methacrylamide copolymer with narrow molecular weight distribution via acid-sensitive hydrazone linker. The structure of the linker plays a crucial role in the biological effectivity of the delivery system, so it was optimized to be stable at pH 7.4 (representing the pH of blood plasma), whereas in slightly acidic pH in endosomes after the cell internalization, the radioiodine-containing biologically active intercalator is rapidly released from its polymer carrier. The intercalating ability of the active compound was...
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Diversity and abundances of birds along altitudinal gradients of Cameroon Mountains
Dubský, Marek ; Sedláček, Ondřej (advisor) ; Reif, Jiří (referee)
The aim of this thesis is to describe the changes of bird species diversity along elevation gradient on six mounts in Cameroon and nearby Bioko island. The results of the analyses confirm most of the defined hypotheses, especially they show that species diversity declines with altitude and rises with area. Cluster analysis shows the similarity of individual mountains in particular altitude zones. Despite the original hypothesis, mount Cameroon is found to be most similar to mount Kupé, although high mountain assemblages of mount Cameroon and Bioko island are very alike as well. The absolutely highest diversity was detected on mount Cameroon and mount Kupé, but above 2100 m above sea level mounts Oku and Manenguba are the most diverse. The results of this thesis contribute to a clearer notion about factors influencing species diversity; however, more thorough data (particularly from mount Nlonako) and data extension for e.g. bird abundance would enrich the study and it would enable us to perform more detailed diversity analysis, especially an analysis of competition relationship among species. Key words Species diversity, Cameroon, bird assemblages, elevational gradient
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The role of interspecific competition in ecological differentiation and speciation in two passerine species, Luscinia megarhynchos and Luscinia luscinia
Sottas, Camille Pauline ; Reifová, Radka (advisor) ; Krist, Miloš (referee) ; Sedláček, Ondřej (referee)
(in English) Interspecific competition is assumed to play an important role in the morphological and ecological differentiation of co-occurring species and could contribute to their speciation. However, empirical studies showing a direct association between competition, ecological niche divergence and specific morphological adaptations are scarce. This thesis focuses on the role of interspecific competition in the differentiation and the evolution of reproductive isolation between two closely related passerine species: the common nightingale (Luscinia megarhynchos) and the thrush nightingale (Luscinia luscinia). Both species are insectivorous and have similar ecological niches. They have diverged 1.8 Mya and their areas currently overlap in a secondary contact zone, where both species still occasionally hybridize. Previous studies have reported an accentuate bill size divergence in sympatric populations compared to allopatric populations, suggesting that interspecific competition might have resulted in feeding niche divergence between the two species in sympatry. Within this PhD thesis, I have studied potential associations between bill morphology divergence, diet composition, habitat use and gut microbiota composition. We found that the two nightingale species have diverged in feeding niche in...
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Species traits and ecological conditions linked to bird colonisation of cities
Grünwald, Jan ; Reif, Jiří (advisor) ; Sedláček, Ondřej (referee)
Human settlements are a novel habitat type and species must respond to its ongoing expansion. For effective conservation of biodiversity, it is important to understand the mechanisms underlying these responses. This thesis focuses on urbanization in birds, from both the individual and community perspectives. The aim of this thesis is to find out if there are any "pre-adaptations" in some bird species to be successful city dwellers or if all birds can potentially exploit the urban environment when local conditions allow. According to the reviewed literature, I conclude that the urbanization in birds is not a universal pattern, but there are some specific traits shared by most of the urban birds. The successful urban species are mostly omnivorous or granivorous, they breed in trees or in cavities and, they are often ecological generalists. They are sometimes represented by non-native species occurring in the cities all over the world.
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Conservation of populations on the edge of geographical distribution
Pešová, Lucie ; Sedláček, Ondřej (advisor) ; Šípek, Petr (referee)
Populations on the edge of the range are often considered less valuable for conservation with regard to core populations of the species. These populations are often small, isolated and less genetically variable, and are therefore more prone to extinction. On the other hand, there are some studies claiming that some peripheral populations could have genetically unique allels which could help them adapt to changing environmental conditions. They thus have a big speciation potential. Peripheral populations could also occur behind state borders, where the species has conservation status, despite the fact that it is a common species somewhere else in its range. Due to this contradiction, peripheral populations are a delicate topic of discussion in the scientific community. In this paper I summarized the features of populations on the edge and also factors which limit them. Furthermore, population dynamics of these populations and summary of the main genetic processes taking place in small populations are outlined here. Next there are arguments for and against conservation of populations on the edge. In conclusion I give model examples of species on the periphery, demonstrating their features and reasons for their possible conservation. Key words: population, conservation, peripheral, marginal, range...
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