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Effectivennes of wader conservation
Mantičová, Mária ; Reif, Jiří (advisor) ; Kubelka, Vojtěch (referee)
The decline of many wader species (Charadrii) is globally significant, more than a quarter of species are at a certain level of threat. The decline in their populations is also a bioindicator of global problems, such as the water loss in the land. Waders are globally threatened by many factors, the most important are: habitat loss, changes in agriculture and higher predation pressure. The aim of my bachelor thesis was to create a background research on the effectiveness of protection of waders and to evaluate the impact of conservation actions on selected species. In most cases, they were agro-environmental schemes (AES), artificial creation and restoration of habitats, and active nest protection. The results of expert studies indicate that waders often occur at created or managed sites in higher numbers, but for overall recovery and increase of productivity of wader populations this is not sufficient in many cases. In the future, it would be necessary to extend globally those management measures that were essentially successful at particular locations and, in addition, to introduce further measures that are supposed to be successful despite the complexity of their implementation. Key words: waders, conservation, management measures, AES, threat
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Extinction risk and population size
Váňová, Lenka ; Storch, David (advisor) ; Reif, Jiří (referee)
There is generally accepted assumption that the probability of extinction risk increases with decreasing population size. But it's not sure at all, to what extent does this relation really work in real populations. The amount of studies dealing with this topic is on the increase, but still it's necessary to carry on researching. Previous results indicate that inspected connection is indeed true in many populations, in other words, preferential extinction of less abundant populations functions properly. Yet the dependence isn't as unambiguous and strong as expected. Many exceptions are known as well, which demonstrate that low number of individuals doesn't always have to be a disadvantage in terms of survival chance. Such deviations can be found both in paleontological papers and among current populations. For example, mass extinctions represent that kind of a special exception because each of them was probably driven by a different mechanism, so in one case the abundance could be an advantageous trait, whereas in another it was rather disadvantage. In my work, I briefly mention themes referring to extinction in general and subsequently I try to summarize findings about the phenomenon of population size and its connection to extinction risk. On the basis of explorers' ideas and by means of...
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Habitat as a determinant of abundance and distribution of birds in space and time
Reif, Jiří ; Storch, David (advisor) ; Fuchs, Roman (referee) ; Konvička, Martin (referee)
of the thesis The thesis focuses on various aspects of bird-habitat relationships. We found that the positive correlation between local abundance and regional distribution of birds is not a universal pattern. Its strength and direction depends on the similarity of habitat cover at the locality where the species abundances are measured and habitat cover of the wider region where the species distribution is assessed. In the case of the Cameroon Mountains, many locally abundant species had relatively small ranges in subsaharan Africa. They were probably well-adapted to specific conditions of montane environment, and such tight habitat association precluded their occurrence in regions covered by savannah or humid lowland forest. At the same time, isolation and unusual environmental conditions of the montane forest in the Cameroon Mountains reduced possibilities of their colonization by species widespread within Africa. Such species were confined to deforested areas in the Cameroon Mountains. The strongest gradient in bird community structure was between birds of montane forest and birds of non-forest habitats, and this gradient is probably one of the most important bird-habitat gradients worldwide. Endemic species and species confined to afrotropical mountains had the highest association with montane...
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Can the capercaillie (Tetrao urogallus) reintroduction be successful?
Stelšovská, Lenka ; Křenová, Zdeňka (advisor) ; Reif, Jiří (referee)
The western capercaillie (Tetrao urogallus) used to be a common species in Europe but, during the last decades, the species declined rapidly in the western part of its range, i.e. in Central and Western Europe. Decreasing of the habitat quality, inappropriate forest management, climate changes, disturbing by humans (sport & tourisms) together with very only low adaptabity of this species were recognized to be the most important factors threatening Tetrao urogallus. Also predation is a very important stress factor. Numbers of reintroduction projects have been conducted in Europe to improve the situation. This study summarizes current knowledge about reintroduction projects and their effectivity. Most of the projects were not successful very much. Reintroduction projects were implemented also in the Czech Republic in 1998 - 2007 and capercaillies have been released in several regions (Šumava, Český les, Krkonoše, Jeseníky, Moravskoslezské Beskydy, and Brdy). No new populations were established. The reasons for the failure have been found in the insufficient quality of the biotopes, predation, the physiological and ethological deficiencies of the young birds and the ways of their rearing. It is possible to summarize, that the reintroduction projects seem to be low effective but they are not completely...
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The importance of woodlots for birds in farmland
Rajmonová, Lenka ; Reif, Jiří (advisor) ; Zasadil, Petr (referee)
One of the outcomes of agricultural intensification is landscape homogenization, particularly obvious in developed countries. Unproductive plots of woody vegetation may represent a refuge for many species within large blocks of open areas. Eventhough it is crucial to assess the importance of such plots for animals in farmland, surprisingly, no synthesis on this topic has been published up to now. Therefore, performance of such an assessment is the main task of this bachelor thesis which is focused on birds since they heavily suffer from agricultural intensification. It was found that marginal vegetation provides not only habitat for breeding and foraging but also ecological corridor for birds᾽ short-distance movement and stopover sites for long-distance migrants. The structure of avian community is affected by specific characteristics of vegetation itself considerably and also by characteristics of landscape in smaller measure. Both farmland and forest birds occur in marginal vegetation, each of these bird groups utilizes these plots in a different way based on its ecological needs, however. The understanding of these mechanisms will allow effective conservation of biodiversity and restoration of once devastated areas. The main goal of conservation should be to ensure heterogeneous landscape mosaic...
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The impact of climate and land-use changes on birds
Koschová, Michaela ; Reif, Jiří (advisor) ; Sedláček, Ondřej (referee) ; Musil, Petr (referee)
Climate changes associated with increasing global temperature affect bird species. As a result, breeding ranges of European bird species will probably shift in future. Although it is unclear whether these shifts will come true, we can already see patterns recent bird population trends consistent with the impact of the changing climate. The results of our first analysis based on large-scale monitoring data showed that species with more northern latitudinal distributions had more negative population trends in the Czech Republic. Climatically induced shifts of species' geographic ranges can also provide important information about the potential future assembly of ecological communities. For this purpose we calculated the potential shifts of breeding ranges of European birds and explored their relationships with ecological variables to detect which ecological groups of birds will be most likely forced to move their ranges. Breeding habitat type showed the strongest relationship with the potential range shifts. The magnitude of the shifts can be considered as a measure of the climate change pressure on species. From this perspective, it is interesting to ask how these shifts relate to current species' population trends. Therefore we related the potential shifts to the long-term population trends of...
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Bird communities in stands of non-native trees
Hanzelka, Jan ; Reif, Jiří (advisor) ; Hořák, David (referee) ; Šálek, Miroslav (referee)
6 Abstract This thesis deals with the effects of non-native tree stands on birds in the Czech Republic. Non-native plants, including trees, are known to adversely affect the biodiversity. At the same time, birds represent a widely used biodiversity indicator. The studies of bird communities in stands of non-native trees presented here show the extent to which the birds have been impacted by non-native tree stands. This knowledge can be used to evaluate the importance of non-native plants as a biodiversity threatening factor. As the representatives of widespread non-native trees, the broad-leaved black locust and coniferous black pine were selected. In these stands I investigated possible mechanisms affecting bird communities, arising from assumed differences in vegetation structure, bird species richness, bird community composition, food supplies, and nest predation pressure compared to the stands of native oak and native Scots pine. In general, the bird species richness positively correlates with the vegetation structure complexity. Despite the fact that the non-native stands proved to have a higher heterogeneity of vegetation structure than the native stands, bird species richness did not differ among the focal stands. The bird community composition was primarily affected by the birds' preference of...
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The role of high-altitude habitats for speciation of central European endemics from the genus Campanula
Folbrová, Magdaléna ; Šemberová, Kristýna (advisor) ; Reif, Jiří (referee)
Mountain environment plays an important role in plant's life. Extreme conditions lead to continuous speciation accompanied by a complex processes e.g. geographical isolation (variation) or polyploidization. These processes can be studied by using a suitable model plant, represented in this thesis by selected mountain endemic bellflowers species belonging to Campanula rotundifolia agg. These species appear to be morphologically very similar but they are supposed to be of different origin. Mountain ecosystem is considered to be one of the most diverse and the most valuable environment for nature conservation. It hosts many endangered plants as well as plants protected by law. From the model group, these plants are represented by Campanula bohemica Hruby, Campanula gelida Kovanda and Campanula rotundifolia subsp. sudetica (Hruby) Soó. This thesis aims to sum up the up the current knowledge about a high altitude environment and endemism and to give a description of speciation mechanisms leading to the variability of mountain Campanula species. Further descriptions of their endangerment level, conservation and origin are also given. The subsequent MSc Thesis, introduced in the last part of this thesis, aims to reveal the origin of Czech and Slovakian mountain Campanula endemics. It is mainly focused on...
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