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Growth and mortality of natural regeneration after dieback of tree layer of mountain spruce forest
Červený, Jan ; Bače, Radek (advisor) ; Synek, Michal (referee)
The aim of this study is to assess the state of the natural generalization after the death of the upper tree layer in the mountain spruce forest, based on data acquired on permanent research area (50x50 m) where the collection of the data is in progress since 2006 in the area Trojmezná. These areas were damaged by hurricane Kyrill and afterwards bark beetle calamity in 2008. In these areas were defined squares of size 5x5m and they were divided into cells 0,5x0,5m and these shelf is recorded every individual, the increment, health and microhabitat. By the analysis which was carried out, was found, that woody representation is not different from the representation of upper tree layer, the number of spruce is 97% and 3% of the crane. Most individuals were caught before the disturbances, the youngest individuals germinated in 2006. Higher individuals achieve higher gains than smaller individuals, it means that the heterogeneity of the height structure is increasing. Based on analysis of mortality individual squares (50x50m) was found that after the disturbance on TVP new places without trees were not formed. The dependence of mortality on frequency of individuals in the cells (0,5x 0,5m) has not been demonstrated. That means that mortality of individuals at intraspecific competition is yet significantly independent, although abundance exceeded 17 individuals per cell. Eight years after disturbance is mortality very low. The highest regeneration grows up to 20 cm per year.
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The Impacts of Non-native Species American Mink (Neovison vison) on Native Fauna
Moucha, Pavel ; Vrabec, Vladimír (advisor) ; Jan, Jan (referee)
The American mink is among the weaselly (Mustelidae) carnivore native to North America. It is a food opportunist living semiaquatic lifestyle. He is very well adapted to the new environment. And he was introduced by humans as a furry animal to many areas of Europe, Asia, South America and other areas. Secondarily often he escaped or were released into the wild, where he managed very well prosper and continue to reproduce. To the Czech Republic came as a furry animal in 20. to 30. years of the last century, in the wild he was then observed since the 60s.
This study examines the impact of American mink on our fauna, especially in view of the food spectrum. The research was conducted in the middle of the river Berounka in Křivoklát from December 2014 to December 2015. The aim of the study was to capture the largest possible number of minks during the summer and in winter. Another aim was whether mink dangerous for the local population of reptiles.
Trapping took place during the 552 trapping night. a total of 20 were trapped mink. This means that the average captured 1 mink to 28 trapping night. Of these 20 individuals were 5 females and 15 males. It caught up to 8 mink in the winter and 12 in the summer. Based on the analyzes were 7 mink (35 %) excluded from the analysis because of an empty stomach. The largest component of food mink accounted for 76.16 % mammals for example order: Rodentia eg. vole (Microtus arvalis), muskrat (Ondatra zibethicus). Other food components formed on the same level with a share of 7.69 % reptile grass snake (Natrix Natrix), birds (order: Passeriformes) and fish (class: Actinopterygii). The last component of food occurring in the samples was 0.77 % of the insects (orders: Coleoptera, Lepidoptera). In the analysis wasn´t detected representative of the class of amphibians (Amphibia). The food spectrum in the winter and summer season was no different. At-risk populations reptile shows finding snakes in the stomach mink. An important outcome of this study is also alert to legislative issues concerning the mink in the Czech Republic and the possible effects on the otter (Lutra Lutra).
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Vliv kompetice na růst výmladků dubu zimního na výzkumné ploše Hády
Duda, Jan
This thesis deals with competition effect on sprouts growth of sessile oak (Quercus petraea agg.). It analyze dimensions and growth of sprouts in 5 growing seasons. It investigates competition effect to height increment and diameter increment of sprouts on areas in corversion to coppice and coppice with standarts. Measurement was realized in the area of ŠLP Křtiny, specifically on research area Hády. It was found, that with increasing age decrease the number of sprouts gradually. It was demonstrated, that sprouts are growing better, and achieves a higher dimensions in area without standarts. Competition effect was certified to height increment and diameter increment at the entire growth period.
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Puccinelia distans and Digitaria sanguinalis as a phenomenon of road verges
LAXOVÁ, Lenka
The main subject of this bachelor thesis is establishment the main phenological phases of two grass species Puccinelia distans and Digitaria sanguinalis, which occur in vegetation bands along the roads. It also deals with change of their dominance during one with higher soil salinity along roads near the town České Budějovice. The soil conductivity on road verges was measured, too. Collected information and field data from certain localities were proccesed into tables, diagrams and summary resuls. The tendency in phenological phases exchange confirmed propagation and existence of theese two species on joint area during thge spring and summer seasons. It shows an adaptation of both plants into salt contaminated soil. Soil conductivity shows fluctuating trend in soil salinity during the year on road verges
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Demonstration of the basic characteristics of population dynamics in the school aquarium synchronization of ecdysis and food availability in a model organism.
HROUDOVÁ, Eva
This bachelor thesis is focused on the synchronization of ecdysis and food availability in semiaquatic bugs Microvelia reticulata (Heteroptera: Gerromorpha). Ecdysis, or molting, is a process when an individual sheds the old cuticle and gradually replaces it by a new one. The main task was to determine whether the ecdysis is influenced by the presence of food. It was also necessary to assess whether such an experiment would be feasible within the school environment. There were 18 cohorts with initial number ca 20 individuals each monitored during this experiment. The cohorts were fed every second day and every day the number of molts and deaths was recorded. Three methods of analysis - 2 test, t-test analysis and nested ANOVA were used for determination whether ecdysis depends on food availability. The results show that the food availability may influence the molting, when higher molting rate was usually in the days without food. It is thus possible M. reticulata nymphs are limited by competition and prefer molting during the food shortage. This long-term experiment is not appropriate in a normal school environment, it is very time and space consuming, and failed to show convincing results.
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Mathematical modelling of competition between African carnivores
RYCHTECKÁ, Terezie
Two types of mathematical models incorporating several types of competition between two species of African carnivores were constructed and analysed. The heuristic model focuses on population dynamics of both carnivores and their shared prey. The individual-based model focuses on the role of habitat heterogeneity and unique features of ecology of one of the predators, using the African wild dogs and hyaenas as a case study.
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Comparison choice cultural and weed kinds form stock Amaranthus
VÁLEK, Jan
Amaranthus (L.) belongs to among old cultural crops. Cultural forms of some species were already grown by Aztecs and Incs in ancient times. High nutritive value of seeds redounded to rediscovery of the crops. Tested varieties of cultural amaranth get to the interaction whit wild species of amaranth. This work would had contribute to better knowledge of ecology in the hybrid of cultural variety and weed (A. x turicensis = A. cruentus x A. retroflexus) The aim of this work was to describe production and morphometric characteristics of selected relative cultural and weed species of amaranth (Amaranthus hypochondriacus, Amaranthus cruentus, Amaranthus retroflexus), the hybrid A. x turicensis and to determinate occurrence and survival of weed species A. retroflexus onplaces, where cultural amarant was grown. A. retroflexus shows as a very resistant to damage. Cultural species responded on damage by reduction of majority observed parameters. Cultural species of amaranth responded more on different conditions substrate than the weed species. Response of hybrid on different substratum conditions was in the middle of spectrum of the response in cultural parents and the weed species. Indiference of the hybrid to substrate should be better clear up in the next studies. Weed species is little sensitive to competicion and his characteristics (total biomass, legth inflorescence, height of plants, number of leaves) are different not much. Effect of competition on hybrid shows his non - uniform response probably caused by his considerable variability Absence of cultural amarant and interspecific hybrids shows on relation of these plants to warmer weather that is probably the main factor for their occurrence.
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