National Repository of Grey Literature 99 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Long-term population trends in urban birds in Europe and Czechia
Grünwald, Jan ; Reif, Jiří (advisor) ; Sedláček, Ondřej (referee)
Urbanization ranks among the most important processes induced by the human civilization that affects ecological communities at the same time. Birds are the most frequently studied organisms in relation to urbanization. Different birds' species show different abilities to adapt to urban areas, so urbanization works as an environmental filter. As urban environment undergoes extraordinarily high rate of change, the characteristics of the environmental filter are changing rapidly, too. This could influence populations of urban bird species. We can expect that the population change of the species will be related to the time since urbanization; specifically, the early urban colonizers will decline due to alteration of urban environment, while the recent urban colonizers will increase. I obtained data on population trends from 2000 to 2016 for 95 common urban bird species in 16 European countries. Thanks to the cooperation with local expert ornithologists, I collected the data about the time since urbanization of these species in respective countries and I related these two variables filtering out the influence of 9 other species-specific ecological characteristics. Bird population trends had a statistically significant relation to the time since urbanization: the species that became urbanized earlier...
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...
How do bird species richness and abundance differ between military training areas and surrounding landscape? A case study from the Hradiště military area
Bušek, Ondřej ; Reif, Jiří (advisor) ; Koleček, Jaroslav (referee)
Since the beginning of the 20th century human land use changed drastically in Central Europe. These changes included: homogenization of the landscape mosaic, intensification of agriculture, urbanization and land abandonment. In turn, these changes affected bird species and perhaps most significantly manifested in population decline of open habitat birds. Therefore, it is important to investigate sites, which were not affected by the changes mentioned above, such as military training areas (MTAs) - places dedicated to training of armed forces. Previous studies have shown that MTAs seem to host remarkably high bird diversity and abundant populations of bird species of conservation concern. This may be caused by two major factors. First, closure of MTAs to all human activies besides military training spared them of the landscape changes mentioned above. Second, the military training itself produces a very heterogeneous habitat mosaic that allows coexistence of many species with different ecological requirements. To my knowledge, no study compared bird assemblages between MTAs and surrounding landscape directly. At the same time, such data are crucial to assess the value of MTAs for bird conservation reliably and, as a consequence, they enable to think more deeply about mechanism generating this value....
Availability of urban green spaces in European cities
Malach Čejková, Petra ; Čihař, Martin (advisor) ; Reif, Jiří (referee)
Most of the European population and half of the world population lives in cities and their share will probably continue to increase (UN, 2010). With increasing urbanization, urban green spaces are becoming the most available means of contact with "nature" for more and more people. The aim of this bachelor thesis was to try to determine which factors affect the recreational use of urban green spaces. As the main factor was expected the availability of green spaces, ie. their quantity in the area of residence. The basis of the thesis was available literature on this subject, confronted with the outcomes of visitors monitoring in five forests in Prague between May 2009 and April 2010. The visitors monitoring followed a long series of studies, which were executed mainly by Institute for Enviromental Studies, Faculty of Science,Charles University, mostly as a dissertation thesises, in Prague forests and in Czech national parks. In this submitted thesis, particular attention was paid to data from the Prokopske udoli, where the author coordinated the visitors monitoring. During the 12 days of visitors monitoring, 14 359 visitors passed through the intersection of the main counting station - of which 59% walkers and 41% cyclists, moreover 868 dogs, 388 cars and 456 prams. Total estimated traffic is in the...
Interspecific hybridization in birds: lessons for conservation
Štěpánková, Klára ; Reif, Jiří (advisor) ; Vokurková, Jana (referee)
Interspecific hybridization is quite common in recent years. Favorable factors are rarity of a species, limited time for partner selection, misdirected preference in mating partner selection of females, preference for males with more pronounced sexually selected traits, greater body size and habitat destruction. Factors which lead to the artificially interspecific hybridization due to habitat destruction include deforestation, fragmentation of the territory, urbanization, abandoning agricultural areas, as well as translocation of species into the regions where they did not originally occur. These species can later interbreed with the native species and if the latter are rare and the former aggressive, it can result in increased threat potentially leading to extinction of indigenous populations. Exceptionally, interbreeding can lead to the emergence of a new species; however, this type of origination of a new species is not common in animals. Hybridization is a natural phenomenon important for the evolution. Nevertheless, anthropogenically induced or assisted hybridization represents a serious problem for the species conservation. Finding a solution to overcome the negative impacts of such interspecific hybridization is difficult and there is no exact and universally applied methodology to date. Key...
Biology of three-toed woodpecker
Navrátil, Martin ; Fuchs, Roman (advisor) ; Reif, Jiří (referee)
In my thesis I have tried to find out how does forest management influence presence of the Three-toed woodpecker Picoides tridactylus.This species is considered a "flagship species" of an untouched primeval type of forest and therefore it requires our attention and protection. The thesis contains results of North-American studies focused on the species very similar to Picoides tridactylus. The main chapters are those aimed to provide information about how is the Picoides tridactylus affected by forest fragmentation, stand health condition and finally the impact of food supply on the occurence and behaviour of the species.
The effect of agri-environmental schemes on biodiversity
Vodička, Jan ; Reif, Jiří (advisor) ; Kindlmann, Pavel (referee)
The aim of thesis is summary of current results of scientific publications evaluating effectiveness of agri-environmental measures in the relation to biodiversity. This work deals with this issue in Europe, characterizes the situation in selected European countries and evaluate the effectiveness of compensation schemes and individual measures on selected groups of organisms. It also deals with the factors influencing the effectiveness and methodical approaches of evaluation studies. Results of studies suggest a low to medium efficiency of allover measures for plants and invertebrates and low efficiency for birds. Conversely targeted measures had a high efficiency, but their overall significance was very low due to small proportion of land compared to the horizontal measures.The worst situation was in the Netherlands, in other countries the results were relatively similar.
Industrial melanism in the context of ultraviolet reflectance
Stella, David ; Kleisner, Karel (advisor) ; Reif, Jiří (referee)
This work focuses on the topic known as industrial melanism. The main aim of this thesis is to summarize the knowledge published on this topic. The first mentions about industrial melanism appeared in England in the end of 19th century. Many different hypotheses emerged during the last one hundred years. The work starts with introduction of the fundamental theory of industrial melanism in the context of environmental change during last three hundred years. Furthermore, the historical development of ideas on industrial melanism is given and contemporary hypotheses are discussed. Significantly, work deals with the biological role of UV reflectance in the context of industrial melanism.

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