National Repository of Grey Literature 22 records found  previous3 - 12next  jump to record: Search took 0.01 seconds. 
Impacts of deforestation of west African mountains on biodiversity
Stříbrská, Eliška ; Hořák, David (advisor) ; Reif, Jiří (referee)
The high rate of deforestation is a global problem with negative impacts on species biodiversity and it also contributes to global and local climate changes. This problem is much more urgent in hotspots of biodiversity and endemism like west African mountains. Moreover, these locations are now recognized as the most fragmented and the most deforested mountains on the African continent. Impacts on local organisms is mostly negative. The organisms are facing habitat loss and the inability to migrate between the isolated regions. The bond between associated animals and plants, that are life depend on each other, is being broken and the whole ecosystem is being changed. In general, the ecosystem is less stable and all these changes make deforestation a chain reaction. Although there are some positive impacts on the biodiversity too, it does not influence the endemic species. It has more positive consequences for the generalist species occupying wide range of habitats and utilizing various food resources. Local communities are also facing the impacts of the ecosystem changes, their lives are negatively influenced by longer and more intensive periods of drought, landslides and they are not able to rely on the supply of the forest products. To be able to change current situation, financial support and...
Evolution of endemism of mountain animal species
Švihálková, Tereza ; Munclinger, Pavel (advisor) ; Hořák, David (referee)
The mountain islands, isolated habitats surrounded by a distinct lowland environment, are home to a variety of endemic animal species. These hot-spots of biodiversity and endemism can be found mainly in tropical areas. Thus, the occurrence of endemics partially corresponds to the general macro-ecological rules of biogeography. For a more specific explanation of the origin and evolution of mountain animal species, we usually proceed from two theories - vicariate and dispersion. The validity of these theories varies in relation to taxon, locality, and evolutionary past, so it is difficult to generalize them globally. This bachelor thesis summarizes the prerequisites for the occurrence of endemic species and knowledge from some world- important mountain localities with a large number of endemic animals.
Utilization of Biology Olympiad in schools and implementation of selected tasks into highschool teaching.
Dvořáková, Darina ; Janštová, Vanda (advisor) ; Drda Morávková, Alena (referee)
This thesis deals with the Biology Olympiad and remaking of selected tasks of region round. The remaked tasks can be used in highschool education. The thesis includes theoretical and practical part. The theoretical part provides general information about the Biology Olympiad (BiO), charts the achievements of Czech students in International Biology Olympiad (IBO), includes literary review of selected topics. The practical part encompass four remaked tasks of different topics: Eucaryotic cell as a mosaic, Water in life of animals, Animals' areas and their distribution, History of the flora in Czech Republic. The tasks are processed in the form of worksheets. The worksheets were tested at schools. Knowledge of students was tested by using of created pretests and posttests. The practical part also presents the result of research based on a questionnaire survey focused on the involvement of school in BiO and teachers' opinions on these topics.
Aquatic fauna of karstic fields in the Balkans
Doulíková, Tereza ; Vukićová, Jasna (advisor) ; Kalous, Lukáš (referee)
Dinaric Karst region of the Balkan Peninsula is one of the hot spots of biodiversity, and it is characterized by a high degree of endemism of freshwater fishes. Numerous geological and climatic events have influenced the formation of the area and speciation. Karst poljes are the specific features of Dinaric Karst. They represent a specific ecosystem full of endemic species, where hydrogeological processes play an important role. The periodic flooding appears on poljes. It leads to activation of various underground channels and their interconnection. Twenty two endemic fish species have adapted to this regime. They live in underground waters or in surface waters part of the year and they can migrate between poljes through karst channels. They show significant reduction in size and change in complexity of scaliness. Scales are small and they are barely visible in some species. All these species and abundant underground karst fauna are threatened primarily by pollution, habitat destruction, and drainage of poljes.
Development of endemic freshwater ichthyofauna of Greece
Kyralová, Eva ; Vukićová, Jasna (advisor) ; Švátora, Miroslav (referee)
The Balkans is one of the hot spots of biodiversity, and is known for a high diversity and endemism of freshwater fishes. The development of Greece was significantly affected by the climatic, geologic and orogenetic events resulting in high concentration of freshwater fish endemism. Some of the important historical events were the emergence of land bridges during the early Oligocene and Miocene, through which freshwater fishes dispersed to the Balkans from Asia and subsequently to Africa, the freshwater phase of the Paratethys sea or Alpine orogeny, which began 65 million years ago, and which gradually formed the Greek mountain systems, leading to a long-term isolation of local freshwater ichthyofauna and subsequent speciation. Other major events include Messinian salinity crisis and Pleistocene climate oscillations. Most of the freshwater fish families occurring in Greece most probably originated in the Southeast Asia, from where they colonized the Balkans by several routes. These colonizations took place repeatedly at different times and by different routes. The dispersion of freshwater fishes from Asia to Europe through Siberia started before the uplift of the Ural Mountains about 33 million years ago and continued until Pliocene. Another important colonization route from Asia was via the...
Risk assessment of interspecific hybridization between endemic Campanula bohemica and widespread C. rotundifolia s.l.
Hanušová, Kateřina ; Suda, Jan (advisor) ; Krahulec, František (referee)
The thesis deals with phenotypic, ploidy and genetic variation of two Campanula species occurring in the Krkonoše Mts., namely the endemic C. bohemica and widespread C. rotundifolia subsp. rotundifolia. For comparative purposes subspecies sudetica of the latter species was also included. The main aim was to get insight into population structure and assess the threat of interspecific hybridization to the survival of the endemic bluebell. Flow cytometry, distance-based morphometrics and molecular analysis were used to address these questions. Three distinct groups of fluorescence intensities were revealed by flow cytometry, corresponding to DNA diploids, tetraploids and pentaploids. While diploids morphologically matched the nominate subspecies of C. rotundifolia, tetraploids corresponded either to C. rotundifolia subsp. sudetica or C. bohemica. Most populations from the Krkonoše Mts. were uniform although a sympatric growth of diploids and tetraploids was encountered in 12 populations. Only two pentaploids individuals, most likely of hybrid origin, were found, which indicated that interspecific hybridization is much less common than previously assumed. The two tetraploid taxa were distinguished by molecular markers. A combination of flow cytometry and molecular analyses thus allowed reliable...
Evolutionary history of tetraploid representatives Galium pusillum group (sect. Leptogalium) in central Europe. Allopatric differentiation of Czech endemic species G. sudeticum
Knotek, Adam ; Kolář, Filip (advisor) ; Chrtek, Jindřich (referee)
The presented study tries to reveal the evolutionary history of polyploid complex Galium pusillum aiming on a rare czech endemic species G. sudeticum, an ideal model to study allopatric speciation in the context of Central European (post)glacial development. The species G. sudeticum grows in Krkonose Mts. and on serpentines in western Bohemia (Slavkovský les) more than 200 kilometers away. Our morphological and molecular data suggest a clearly different history of its two isolated areas. The populations in Krkonose Mts. are probable relics of mountainous species G. anisophyllon which was there on its northern border of occurence and hybridized with lowland species G. valdepilosum during postglacial vegetations shifts. This fact is well supported by intermediate position of Krkonose Mts. populations in both morphological and molecular AFLP analyses and by sharing the same chloroplast haplotype with geographically close lowland populations. On the other hand the serpentine lowland populations in western Bohemia are both morphologicaly and genetically indistinguishable from G. valdepilosum. Distinct genetic lineage of few populations belonging to G. valdepilosum (incl. one traditionaly referred as G. sudeticum) was found in western Bohemia and Bavaria, located on relic stands (calcareous and serpentine...
Diversity of bird species along elevational gradient on 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. The absolutely highest diversity was detected on mount Kupé and mount Cameroon, but above 2100 m above sea level mounts Oku and Manenguba are the most diverse. Other analysis showed that the biggest changes in beta diversity of bird assemblages along altitudinal gradients are on the lowest elevational belts which are on the edges of a degraded habitats and continuous undisturbed forests. Other important changes in bird assemblages happen around altitude 1200 m, where the assemblages of lowland rainforest change to assemblages of mountain forest. Analyses of affinity of bird species to forest habitat showed that the most affined assemblages to the forest are those found on mounts Kupé and Rata. On the other hand bird assemblages on mounts Manenguba and Oku are the one of least affined to the forest biotope. Analysis of habitat generalism and specialism did not show the expected outcome and for clearer results the design of analysis needs to be improved. The results of this thesis contribute to a...
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
Western Carpathians as diversity hotspot during the Quaternary climatic cycle
Kubíková, Kateřina ; Juřičková, Lucie (advisor) ; Horáček, Ivan (referee)
In the context of the entire Europe, the Western Carpathians is a unique area of priceless biological significance. Topological complexity, together with significant climatic and edaphic variability, is reflected in the high habitat heterogeneity and has enabled the survival of a large number of species in this area during the Quaternary climatic cycle. The Western Carpathians thus represents one of the most important glacial as well as interglacial refugium in Europe. The result of these environmental variables and the unique history of this region is an enormous species diversity, a high degree of endemism and the occurrence of many glacial relics. This bachelor's thesis contains a review of mainly zoological studies dealing with high biodiversity and degree of endemism in the Western Carpathians and its possible causes. The role of the Western Carpathians as an important Pleistocene refugium, its influence on other parts of Europe and the postglacial development of the area are discussed in individual chapters.

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