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Habitat requirements and predictive distribution modelling of Huperzia selago
Trachtová, Pavla ; Wild, Jan (advisor) ; Douda, Jan (referee)
Studies of the occurrence of montane and boreomontane species in ravines of the sandstone landscape are scarce and the occurrence of these species are explained by the presence of temperature inversion. The question is, which factors limit the occurrence ofthese species in ravines with temperature inversion. The aim of this diploma thesis is to reveal factors that influence the occurrence of Huperzia selago in inverse ravines of sandstone landscape. This work uses a habitat variables recorded directly for populations of H. selago and variables derived from a digital elevation model. These derived variables are also used for creation of two predictive models of geographic distribution of H. selago in the National Park Bohemian Switzerland. When we summarize the most informative variables of predictive models and habitat conditions significantly different from control sites, we get the typical habitat of H. selago. Such sites will likely be found on the rock at the bottom of the valley. Factors that influence the suitability of habitat are: moisture, vegetation type, slope, and distance to the bottom of the valley.
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Does water stress and interspecific competition contribute to the functional divergence or convergence of wetland plant species?
Műnichová, Radka ; Douda, Jan (advisor) ; Alena, Alena (referee)
This diploma thesis is based on the experiment which took 5 years. In 52 plastic containers were planted four species wetland plants; two species of grasses (Calamagrostis canescens and Deschampsia cespitosa) and two species of sedges (Carex elata and Carex elongata). Three types of water regime were set up with: high, low and fluctuating water level, where the high and low level of water took turns after one year. One year before the data collection the strongest competitor Carex elata was cut out. For the evaluation of the role of water level (environmental stress) and removal of the dominant (competition) we selected two functional trait indicators: specific leaf area (SLA) and leaf dry matter content (LDMC). SLA is an indicator of resource strategies, competitiveness and efficiency of light photosynthesis. Species with high SLA are usually better competitors for light, but tolerate harder the environmental stress. LDMC reflects a plants investment in persistent leaf structures and therefore in nutrient retention. A significant effect of water regime on LDMC was observed in the species Deschampsia cespitosa that had higher average values of LDMC in dry water regime, which is indicating higher investment into persistent leaf structures. And the effect of the dominant removal on SLA, where the values of SLA in the containers without removed dominant were higher. Increased SLA implies increased intensity of competition for light. My diploma thesis supported that specific leaf area and leafdry matter content are important functional indicators different types of stress conditions in wetland communities.
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Effect of coniferous monoculture plantation on plant species dversity
Němeček, Jakub ; Vojta, Jaroslav (advisor) ; Douda, Jan (referee)
A structure and a function of a monoculture woodland is diferent from the natural woodland condition. This is an influence of a herb layer diversity. The change of the herb layer are mainly distinguishable in the case of tree coniferous monoculture. They are the poorest at all of them viewpoint diverzity. The diversity of the woodland was analysed with an insuffiently consequence. This study get the knowledge about the species composition and the diversity of these monoculture. At the same time get the knowlege about next factores, which change diversity and species composition of stand. As a confirmation of this, coniferous monoculture are numerously and species-compositionally diferent from broadleave monoculture. And more, coniferous trees change the enviroment's condition and the whole biotopes. There are not depend any species of the herb layer at the coniferous monoculture on this studied site of Křivoklátsko.
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Long-term changes of forest vegetation - the comparison of present species composition and biodiversity with the historical records
Vojík, Martin ; Boublík, Karel (advisor) ; Douda, Jan (referee)
The thesis presents the results of the research of the long term changes in semi-natural vegetation of lowland woodlands in the forest district Klínec (phytogeographical district Střední Povltaví, Central Bohemia, Czech Republic), which is located between the northeastern part of the Brdy Highlands (Hřebeny) and the Vltava River valley. Research of the long term changes over the past nearly 60 years was conducted by resampling vegetation on semi-permanent plots. Old relevés by V. Samek (1957), which were provided by the Czech National Phytosociological database, were used as reference data. Twenty-nine relevés were resampled, which were located using old data and GIS. The shift to shady plant communities (loss of heliophilous and expansion of shade-tolerant species) was found in the study area caused by higher canopy of tree and shrub layer due to the expansion of deciduous trees. Species richness (alpha diversity) was significantly declined. Homogenization of the vegetation was not significantly demonstrated in study area. Species of nutrient-rich habitats as well as alien and invasive species were expanded and fewer red list species of vascular plants was found. Vegetation change in the area was probably most affected by the change in forest management in lowland woodlands (decline of coppicing), eutrophication (deposition of nitrogen from the atmosphere, runoff from agricultural land) and the effect of forest animals especially wild boars.
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Interspecific interactions in wetland communities in dependence on water regime: long-term test of stress-gradient hypothesis
Růžičková, Kateřina ; Douda, Jan (advisor) ; Alena, Alena (referee)
The Stress-gradient hypothesis predicates a change of interspecies relations from negative to positive according to the stress gradient. The basic assumption is that the presence of one species (the facilitator) makes the growth of other species easier. In this study was determined based on the 5years experiment, whether the interspecies interactions (i.e. the importance of facilitation and competition) changes according to the hydrological conditions. Three wetland species (Calamagrostis canescens, Carex elongata and Deschampsia cespitosa) were planted in experimental pots with the presence and absence of the dominant species (Carex elata). The hydrological gradient (= the stress gradient) was simulated by three types of hydrological conditions: dry, fluctuating and wet. The success of the species within the specific conditions was correlated with the fitness-related characteristics of the plants including the biomass, the number of ramets and the height of the plants. Following hypotheses were tested: i) at a low intensity of stress (with the wet treatment), the C. elata represents a competitor for other species. On the other hand, at a high intensity of stress (with the dry treatment), the C. elata represents a facilitator, making it easier to the other coexisting species to grow. This presumption was confirmed only with the D. cespitosa, which was more successful under dry treatment with the presence of a dominant species, which facilitated it. With the other two species the change of interspecific relations was not observed and the relationships remained negative. Furthermore the results showed, that in the dry treatment with the presence of a dominant species, there was a lower intensity of competition among the coexisting species. The experiment showed, that the interactions of particular species with dominant species can vary according to the stress gradient. The hydrological gradient also influences the character and intensity of interactions among the species.
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The influence of the host-plant phenotype on development of phytophagous insect.
Židlická, Dana ; Kadlec, Tomáš (advisor) ; Douda, Jan (referee)
Temperature and other climatic variables, such as the amount of rainfall, are the main abiotic factors affecting the level of herbivory and plant´s properties. Following a change in these factors, the rate of herbivory and the level of plant defence against them alter as well. This bachelor´s thesis examines how a population of a host plant, the red fescue (Festuca rubra), affects the development of the small heath butterfly (Coenonympha pamphilus).
The fescues came from four different locations in Norway with varying local climates. Young caterpillars (first instar) of the small heath butterfly were placed upon the fescues. They are typical generalist herbivores (the caterpillars consume common grass species). 5 or 6 caterpillars had been placed on each plant which were then isolated from the outside environment with a dense monofil. Subsequently, the fescues were moved to an outside bed until the caterpillars created a chrysalis. The survival rate of the caterpillars on each individual fescue was calculated as a ratio of all the caterpillars surviving up to the last instar to the original amount of planted caterpillars.
The caterpillars´ survival rate was better with the fescues originating from a higher altitude (lower average temperatures) and worse with those from lower altitudes (higher average temperatures). This makes it safe to assume that lower altitude plants have adapted better for defence against herbivory. The females overall weighted more than their male counterparts. There was a difference in weight between the populations but the significance of this should be taken with a grain of salt since the number of measured adults was low. The results of this thesis follow the general assumption of the fact that the level of herbivory changes with altitude; with greater heights it decreases
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Flora and vegetation of selected wet and fen grasslands near Havlíčkův Brod
Kutlvašr, Josef ; Boublík, Karel (advisor) ; Douda, Jan (referee)
The research was conducted in the growing season 2015 in selected wet and
peaty meadows near Havlíčkův Brod (Bohemian-Moravian highlands).
Phytosociological classification was carried out using the formalized Cocktail method,
which assigns relevés by formal definitions, and method of assigning according to
similarity of species composition (FPFI index). Nine vegetation groups were
delimitated: seven at association and two at alliance level. Wet meadow of the
association Angelico sylvestris-Cirsietum palustris is the most common community.
Wet meadows of the associations Scirpetum sylvaticae and Lysimachio vulgaris-
Filipenduletum ulmariae (both Calthion alliance) regularly occur. The stands of the
associations Poo-Trisetetum flavescentis (Arrhenatherion alliance) and Poo trivialis-
Alopecuretum pratensis (Deschampsion alliance) was documented at the drier edges
of the localities. Thirteen species listed in the Red list of the Czech Republic were
found. Dactylorhiza majalis, Tephroseris crispa and Valeriana dioica were the most
abundant. Carex hartmanii, Carex paniculata, Eleocharis mammilata subsp.
mamillata, Epilobium palustre, Pedicularis sylvatica, Potamogeton lucens, Comarum
palustre, Scorzonera humilis, Sparganium erectum and Trifolium spadiceum occur
rarely. Some localities (Bartoušov, Čistá, Dlouhá Ves-Pod silnicí, Mozerov a Skorkov)
are suitable for statute significant landscape element for the occurence of these
endangered species.
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Analysis of flight ticket distribution and related services
Veselý, Martin ; Sedláček, Jiří (advisor) ; Douda, Jan (referee)
This diploma thesis analyzes distribution channels of flight tickets on the Internet and aspects related to this type of sale. Individual chapters deal with the historical background, role of e-commerce in the civil aviation industry, individual players engaged in the distribution of flight tickets on the Internet and the position of the online distribution. This thesis also analyzes modern services that are connected to the distribution of flight tickets, e.g. e-ticketing and new forms of check-in.
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