National Repository of Grey Literature 49 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Distribution of population sizes within different orchid metapopulations
Švecová, Magdaléna ; Kindlmann, Pavel (advisor) ; Štípková, Zuzana (referee)
Orchids, as one of the most species-rich families in the world, are known for their specific symbiotic relationships with other organisms and can therefore be referred to as indicators of the state of vegetation. Studying orchids as metapopulations allows us to better estimate the level of threat of individual orchid species. The traditional metapopulation model assumes a metapopulation consisting of sub-populations, where individual populations are connected by migration, and colonization of new and recolonization of existing localities occurs. Orchids, on the other hand, show a different behavior. Their seeds are spread passively by wind, and the colonization of new habitats is therefore rather random. Therefore, a new model would be suitable for the study of orchids, which should include information on the size of the population of a given orchid species, taking into account the region in which they occur. The metapopulation is also influenced by the temperature and amount of precipitation before the flowering period, the possibility of individual sterility or dormancy, and last but not least, the quality of management on the site. These variables should be included in a new metapopulation model that could better describe changes in orchid metapopulations. This thesis provides the basis for a...
Reproductive success in pollinating deceptive orchids
Steffelová, Michaela ; Kindlmann, Pavel (advisor) ; Janeček, Štěpán (referee)
One third of plant species in the Orchidaceae family use a deceptive strategy to fool pollinators. There are many strategies for deceiving orchids, and each has its advantages and disadvantages. Reproductive success is a quantity usually defined as the ratio of the number of fruits to the number of flowers produced by the plant during a given season. It is influenced by many factors. This work is written in the form of a literature review and deals with the factors that influence the reproductive success of deceptive orchids in connection with their pollination. The reproductive success of the orchid depends mainly on the density of the inflorescence, the time of flowering or the place where the plant is located. These factors in turn affect the pollinators, who are largely responsible for the orchid's reproductive success. The specialized strategies of deceptive orchids lead to a decrease in the reproductive success of an individual, but a low population density or lower pollinator attendance at one inflorescence, on the contrary, lead to an increase in the reproductive success of a deceptive orchid individual. Deceptive orchids do not use a strategy that is clearly disadvantageous, so it is unlikely that the orchid will become extinct in the future due to its pollination strategy. Key words:...
Wallachian pastures: condition, preservation and conservation potential
Mizera, Ondřej ; Křenová, Zdeňka (advisor) ; Kindlmann, Pavel (referee)
For centuries, pastures were an important part of the European landscape. Grazing was widespread in the Moravian Wallachia region, where a unique grazing landscape was created. The aim of this thesis is to clarify which pastures were preserved to this day in eleven cadastral areas of the Rožnovská Bečva River valley and evaluates their importance for nature conservation. For this purpose, imprints of historical maps of Stable Cadastre for half of the 19th century were used and a vector layer of former pastures was created. In the ArcGIS Pro program, this vector layer of pastures was compared with the NATURA 2000 habitat mapping layer, the consolidated ecosystem layer (KVES), the zonation of the Beskydy Protected Landscape Area and the network of small-scale protected areas. The current state of former pastures was examined and land used changes between common and private pastures were compared. It was found that a high proportion of historic pastures has disappeared. The main reason for the disappearance is artificial afforestation; other pastures were abandoned and overgrown spontaneously. Some historical pastures, more often common pastures located near the settlements, were built up. The pastures preserved so far are very valuable for conservation and are an important component of the local...
Reproductive success in orchid pollination
Steffelová, Michaela ; Kindlmann, Pavel (advisor) ; Janeček, Štěpán (referee)
The family Orchidaceae is very diverse; it is characterized by specialized strategies for attracting pollinators. Orchid species with deceptive flowers are special in that they do not produce nectar. This has advantages and disadvantages. The type of strategy determines the degree of reproductive success of orchids: sometimes positively, sometimes negatively. Although research on orchids has been going on for centuries, these plants are still not sufficiently studied. This bachelor thesis is written in the form of a literature research and examines the mechanisms that influence the reproductive success of orchids in relation to their pollination. The least studied phenomenon in this area is the relationship between floral display and orchid reproductive success. In most of the studies cited here, there is a linear positive relationship, but the results are far from being conclusive. Key words: Orchidaceae, pollination, reproductive success, floral display, rewarding species, deceptive species
Vegetation changes in transition bogs at fishpond epilitorals
Spilka, Josef ; Karlík, Petr (advisor) ; Kindlmann, Pavel (referee)
This study concerns in a three peatland sites: the epilitorals of Pilská reservoir and Hořejší Padrťský fishpond in Příbram region and Kamenný fishpond in Pilsen. These peat-bobg were affected by negative conseqences of human activities. The aim of this study is to find out what kind these changes was and what extent they were. The changes in vegetation were observed from two points of view. The GIS analyses of aerial photographs represent the macroscale view. Repeating of old phytosociological relevées was the microscale view. To understand the cause of vegetation changes, the species-environment analyses were used. Four transects were made for this purpose and a water table level, pH and conductivity were mesured monthly along these transects. One-shot measurements of N and P water concentration and a peat depth were also carried out. Measured data from transects were uses in multivariate vegetation analyses and also in one- way analysis, aimed to an expansion plant species. All three sites of concern came through strong changes in past. In all of them the area of biotops of great conservation importance decreased and some endangered plant species have been lost there. The changes in Pilská reservoir epilitoral were mostly anthropogenic, whereas the mires of Hořejší Padrťský fishpond and Kamenný...
Differences in spatial distribution and dynamics of bark beetle (Ips typographus) spreading in extensive windfall areas caused by the hurricane Kyrill in the Šumava NP
Janouchová, Šárka ; Křenová, Zdeňka (advisor) ; Kindlmann, Pavel (referee)
Search for the most appropriate forest management in the period of increasing frequency of windstorm and bark beetle outbreaks is a big challenge for foresters and mainly for managers of protected areas. A better knowledge of effectiveness and ecological conseguences of applied methods is necessary for good management of forest ecosystems. The ecology of European spruce bark beetle, natural disturbances occurring in Middle European forests and post-disturbance meausres are reviewed in the first part of this master thesis. Analysis of data about the spatial distribution and dynamics of bark beetle spreading in one of the forest districts of the Šumava National Park and the data about forest regeneration are published in the second part. Own field records together with data from the forest management plan and maps with records of occurrence of the bark beetle infected trees in study area between 2000 and 2006 were used in this study. The significant correlations between occurrence of the bark beetle infected trees and their occurrence in previous years were found. The active management (cutting down and removing of bark beetle infected trees) can't eliminate the bark beetles outbreak. Moreover, the active management causes the fragmentation of canopy and increases the risk of further degradation of...
Impacts of invasive plant species on European environment
Breburdová, Vendula ; Pyšek, Petr (advisor) ; Kindlmann, Pavel (referee)
The DAISIE project in the 6. framework program of the European Union provides valuable data about European invasive species. Invasive plants have various impacts, positive and negative, and effects all four types of ecosystem services (supporting, provisioning, regulating and cultural). Invasive species are also known to cause serious economic looses. The proposed work aims at summarizing the up-to-date knowledge about the impact of invasive flora on European environment and human well-being. key words: invasive plants, impact, DAISIE, Europe, ecosystem services
Measurement of predator effectiveness by means of cage exclusion experiments
Fischerová, Laura ; Kindlmann, Pavel (advisor) ; Tropek, Robert (referee)
1 Abstract Cage exclusion experiments are used in ecological and agricultural studies to determine plant- insect interactions (Kidd & Jervis 2005). Cages are used to detect the insect density on the plant, while other influences such as natural predators or other pests are excluded. Exclusion of predators by using physical barriers (different mesh size) is one of the most used ways to determine the impact of natural enemies on the pest population. The results of these experiments suggest, that the pest population on caged plants, from which natural enemies are excluded, has a lower percentage of mortality and parasitism than the population on plants, where the natural enemies have full access to (Luck et al. 1988). Results of this method are used in programs of biocontrol when searching optimal plant treatments and possible alternatives instead of using insecticides (Lawson et al. 1994). The question is, whether cage exclusion experiments are adequately reflecting changes in pest populations and their impact on plants. As a result of caging the area, changes in microclimate and plant growth occur, which subsequently affects present insect populations. Cages do not also allow leaving the pests from the cage and, in some cases, unwanted natural enemies enter them, even though they have been previously...
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.
Trends in structure of bird communities in the Czech Republic: from diversity to homogenization?
Prylová, Kristýna ; Reif, Jiří (advisor) ; Kindlmann, Pavel (referee)
Biotic homogenization is a process changing functional structure of ecological communities. Bird communities are changing from homogeneous to diversified primarily because specialist species are replaced by non-specialized species (generalists), and in terms of their ecological functions are becoming more similar to each other. Causes can be both in the current climate change and in human-induced land use changes. Using the community specialization index (CSI), I showed that bird communities in the Czech Republic show a trend towards the higher homogenization over the past 20 years. Effect of climate change has been documented by calculation of the community temperature index (CTI), which reflects the relative proportion of species living in lower and higher teperatures. In contrast to CSI, CTI increased over the same time period. Moreover, I focused on the relationship of homogenization with species richness and compared to the results from other countries, it does not change significantly. The observed phenomena were probably caused by a gradual climatic warming in the Czech Republic, accompanied with more frequent occurrence of other climate change symptoms such as severe storms. A second cause underlying the homogenization could be increasing intensity of agricultural production.

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