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Optimalizace těžby přírodních zdrojů
Chrobok, Viktor ; Dlouhý, Martin (advisor) ; Kodera, Jan (referee) ; Vošvrda, Miroslav (referee)
The thesis describes various modifications of the predator-prey model. The modifications are considering several harvesting methods. At the beginning a solution and a sensitivity analysis of the basic model are provided. The first modification is the percentage harvesting model, which could be easily converted to the basic model. Secondly a constant harvesting including a linearization is derived. A significant part is devoted to regulation models with special a focus on environmental applications and the stability of the system. Optimization algorithms for one and both species harvesting are derived and back-tested. One species harvesting is based on econometrical tools; the core of two species harvesting is the modified Newton's method. The economic applications of the model in macroeconomics and oligopoly theory are expanded using the methods derived in the thesis.
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Influence of biotic and abiotic factors on population dynamics of a critically endangered species Spiranthes spiralis
IPSER, Zdeněk
A population of a critically endangered species Spiranthes spiralis was discovered in 1980 in the National Natural Monument Pastviště u Fínů near village Albrechtice, close to Sušice city. Since 1985 the number of flowering individuals in this population has been annually monitored. Since autumn 1998 all the specimen found there have been marked and biometrically measured. During these periods (12 or 26 years, respectively), large year-on-year fluctuations in the number of flowering plants and in the survival of the individual rosettes have been recorded. The main aim of my work was to assess the effect of weather conditions (temperature, precipitation, the number of days of snow) on the population dynamics and on the fitness of plants (leaf area, probability of flowering and probability of death). The year-round lower temperature and the wet end of autumn during the previous year (t-1) together with the wet spring of the following year (t) had a positive effect on the leaf area during the period of maximal rosette growth (end May in the year t). The probability of flowering was positively affected by the lower temperatures in May and June in the previous year (t-1) and in August just before flowering (year t). The probability of death (in the year t) was increased when the March precipitation (in t) and October temperatures (in t-1) were low. The average number of seeds in the capsule was 1528 ? 885 (s.d.). The number of flowers was positively correlated with the number of mature capsules. However, it did not affect the ratio of mature capsules. Capsules developed on average from 44% ? 24.6 % (s.d.) of the flowers. The average life time of individual plant cohorts was 4.7 years. The number of rosettes per each position was variable from 1 to 7 rosettes (73.2% positions had only 1 rosette). The annual life cycle of the underground organs is described at the end of the thesis.
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The infuence of known regulatory factors on the population dynamics of selected orchid species on the orchid meadow (Peklo locality)
ČEPA, Luboš
Populations of strongly endangered species Orchis mascula and endangered Dactylorhiza majalis were monitored at Peklo area since 2000. In May 2002, another strongly endangered orchid species Orchis ustulata was discovered. The major increase in counts of O. ustulata towards stable numbers of O. mascula and D. majalis populations was detected during the seven year period of plant monitoring. The aim of this study was to reveal a connection between the climate conditions and orchid vitality, using biometrical plant data gained between 2005 to 2011. In order to evaluate a steady state of investigated area, the extensive phytocoenological sampling was conducted. The obtained data revealed several different loci at the screened grassland, which can be defined with presence of distinctive species. In blooming individuals of O. mascula, March temperature was the most defining factor. Parameters studied (number of leaves and blossoms, size of leaves, lenght of stems and duration of flowering) increased with decreasing March temperature. The blooming proved to be important factor, if a plant was in flower that year or the preceeding year, the number and the size of leaves was larger. The blooming in two subsequent years enhanced this described effect even more. The comparison of blooming individuals of O. ustulata revealed that plants growing in clusters were non flowering but bigger in size. Other positive correlation with investigated parameters had precipitation in December. However, the comparison of all plants showed generally smaller size of cluster forming plants. This overall analysis pointed out the influence of low temperature in October, the plants were smaller in size and amount of sterile individuals rised. All collected data and generated comparisons support earlier findings about influence of temperature and precipitation on the orchid population dynamics.
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How important are cannibalism and intraguild predation for aquatic insect communities?
PEROUTKA, Miroslav
Cannibalism and intraguild predation in the communities of aquatic insects are reviewed. Special attention is paid to the relationship of predator and prey size and to the impact of cannibalism and intraguild predation on population dynamics and individual life histories. Detection of prey and predator and antipredator strategies are also reviewed. The review is complemented by laboratory experiments on selected species of dragonflies.
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Biodiversity and population dynamics of small terrestrial mammals on various types of restoration in the area of Velká podkrušnohorská spoil heap.
CHARVÁTOVÁ, Pavla
The aim of my thesis was to describe the biodiversity and try to outline the population dynamics of small terrestrial mammals on the Great podkrušnohorská spoil heap. We captured small mammals six times during the 2009 and 2010 seasons. We used the standard capture-mark-release method (CMR) with live traps in quadrates at five sites with different restoration type- wetland, forestry (alderwood and pinewood), agricultural and controlled succession. The observed data were processed in Microsoft Office Excel and by canonical correspondence analysis (CCA) in Canoco for Windows. In 2009 a total of 67 individuals of five small mammals´species were captured: Apodemus flavicollis, Microtus arvalis, M. agrestis, Myodes glareolus and Sorex araneus. The highest biodiversity (3 species) was recorded in wetland restoration. The highest abundance (20 individuals) was recorded in alderwood forestry restoration. In 2010 258 individuals of 7 species were captured: Apodemus flavicollis, A. sylvaticus, Microtus arvalis, M. agrestis, Myodes glareolus, S. araneus and Micromys minutus. As in 2009 the highest abundance was recorded in alderwood forestry restoration(60 individuals) and the highest biodiversity (7 species) was recorded in wetland restoration.
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Těžba v Predator-Prey modelu
Chrobok, Viktor ; Lagová, Milada (advisor) ; Kalčevová, Jana (referee)
The paper is focused on the Predator-Prey model modified in the case of harvesting one or both populations. Firstly there is given a short description of the basic model and the sensitivity analysis. The first essential modification is percentage harvesting. This model could be easily converted to the basic one using a substitution. The next modification is constant harvesting. Solving this system requires linearization, which was properly done and brought valuable results applicable even for the basic or the percentage harvesting model. The next chapter describes regulation models, which could be used especially in applying environmental policies. All reasonable regulation models are shown after distinguishing between discrete and continuous harvesting. The last chapter contains an algorithm for maximizing the profit of a harvester using econometrical modelling tools.
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