National Repository of Grey Literature 18 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Impacts of global climate change on lichens
Šubrtová, Tereza ; Malíček, Jiří (advisor) ; Peksa, Ondřej (referee)
Lichens, also known as lichenized fungi, are primarily known as excellent indicators of environmental change. Due to climate change, lichens are increasingly being studied for their indication and prediction of individual factors of global climate change. In the first part of this work, individual abiotic factors affecting lichens on a global scale are examined, to understand these factors in all possible environments. The next part of the work focuses on Europe and addresses the history of the development and future prediction of lichen distribution under the influence of climate change. The end of the work is focused on the territory of the Czech Republic and mentions the most affected species in our area. The study of global climate change on lichens is important not only for understanding the effects of environmental changes on organisms but also for proper prioritization of nature protection leading to a halt in the decline of species and their habitats.
Pasture of horses as an essential tool in biodiversity conservation
Dudková, Andrea ; Malíček, Jiří (advisor) ; Sedláček, Ondřej (referee)
In recent decades, the approach of active management, preventing overgrowth and simplifying the species composition of non-forest biotopes, has dominated in nature conservation. Dominant plants, suppressing competitively weaker species, are therefore reduced for example by grazing of large herbivores. It turns out that horse grazing has considerable potential for enhancing biodiversity. The aim of this bachelor's thesis was to summarize the main aspects of horse grazing based on literature research and come to a prediction of its future use in nature conservation. Studies on the use of horse grazing in biodiversity conservation show that it works well to suppress competitively strong grasses and supports the presence of flowering dicots and associated insects. The disadvantage of grazing horses is that they do not consume woody plants and thus cannot suppress the growth of bushes. On larger areas (>20 ha), year-round wild horse grazing is used, while domestic horses are suitable for seasonal grazing on smaller sites. Due to the positive results of horse grazing in promoting biodiversity, the more successful suppression of competitively strong grasses compared to other herbivores and the lower level of human effort compared to mowing, it can be expected that cases of using horse grazing in nature...
Functional traits and functional diversity in lichens
Kolenská, Lucie ; Malíček, Jiří (advisor) ; Vondrák, Jan (referee)
Functional traits are a discussed topic across disciplines and articles with lichens are published as well. Traits are the attributes that define the organism from morphological features through anatomy to the physiology of the individual, including interaction in environmental and environmental influences. The most frequently studied functional trait of lichens is the type of thallus. Another commonly studied trait is the type of photobiont, where the presence of algae Trentepohlia is negatively affected by frost and because of this its number decreases with increasing altitude. Another functional trait of lichens which is studied is reproduction, and also secondary metabolites, which protect lichens, for example, against UV light or herbivores. Functional traits together form functional diversity, which is another way how to measure diversity on a planet where the most diverse ecosystem is not always the one with the highest number of species. Functional diversity indices then can reveal unique communities that should be protected. However, neither the definitions nor the calculation of functional diversity are exatly specified, we use different indices. The Rao index of quadratic entropy is most often used for lichens. Keywords indices, lichenized fungi, mycobiont, photobiont, thallus
Epiphytic species of Lecanora subfusca group in the Czech Republic
Malíček, Jiří ; Palice, Zdeněk (advisor) ; Vondrák, Jan (referee)
The main aim of this bachelor work is to summarize knowledges on species of the Lecanora subfusca group growing in the Czech Republic, eventually taxa their occurence may be expected in our area. Only epiphytic and/or epixylic species are included in this study because of a large diversity of the group. Ten taxa have been published from the country. This group is poorly explored in Central Europe because of difficult determination of single species. A comprehensive treatment is lacking in this area. For most taxa of this group only limited information on ecology, distribution, chemistry and taxonomic concepts exists. The present work is reviewing up-to-date knowledge of this group. Historical sources were based mainly on morphological and anatomical data. These were evaluated and excerpted. The bachelor work should serve as a basement for the following diploma thesis.
Lichens and eutrophication
Jadrná, Iva ; Svoboda, David (advisor) ; Malíček, Jiří (referee)
Eutrophication is a process of organic nutrients enrichment in an ecosystem, especially nitrogen and phosphorus. This bachelor thesis is dealing with the influence of eutrophication on lichens, especially with the effect of nitrogen compounds in the air and the effect of the combination of nitrogen compounds with phosphorus on epiphytic lichens. Eutrophication is defined and information is provided on changes in abundance and diversity of lichen cover. The mechanisms of eutrophication tolerance in lichens are also described. Key words: lichens, epiphytes, eutrophication, ammonia, ammonium ions, nitrogen oxides, phosphorus
Uranium mining, its impact on environment and recultivation
Peterková, Alena ; Malíček, Jiří (advisor) ; Frouz, Jan (referee)
In past, the Czech Republic was one of the most important areas for mineral resources mining. In the period after the Second World War, the country was a very important conqueror of the uranium ore, thanks to a massive production of nuclear energy and nuclear weapons. However, in the 1980s, the interest in uranium declined and in the 1990s almost all of the uranium mines in the country were closed. Rožná was the last place of uranium mining, but it was closed in 2017. Nowadays, there are reclamation works in these mining places. Planning of a reclamation for is not always simply. It is necessary to think about the account of the method of extraction, which was used in the territory, the subsoil, distance from dwellings, underground water, fauna and flora of the surrounding nature etc. The land reclamations are often done in the wrong way and therefore, the extraordinary potential of the landscape is not exploited. People have a strong tendency to interfere this landscape, for example by supplying nutrients for creating of an intensive agricultural landscape. They often do not realize that the mining caused a change of abiotic conditions. The newly created habitats are often inhabited by rare and endangered organisms, living in early succession stages and missing in the surrounding landscape....
Lichens and (heavy) metals
Hrdinová, Aneta ; Peksa, Ondřej (advisor) ; Malíček, Jiří (referee)
My thesis is focused on liches and heavy metals. In first part includes the general characteristics of lichens, the short description of their biology, morphology and anatomy. The next part is focused on the characteristics of the methods of absorption of metals by lichens, their physiological effects on the body and the mechanisms of defense against the toxicity of metals lichens. The work includes the list of species of lichen, and their relationships to particular heavy metals. Key words: Lichens, heavy metals, metal tolerance, detoxification, copper
Relationship between the genome size of mycobiont and ecological strategy of lichens
Konečná, Eliška ; Malíček, Jiří (advisor) ; Vondrák, Jan (referee)
The inner organisation of organisms originates from the information contained within its DNA. In addition, the size of the genome itself may influence the function of the organism. Unlike many other groups of organisms, genome size is only known for a very limited number of lichen mycobionts. So far it has been only speculated whether there is a connection between genome size, the ecology and the traits of lichens. The goal of my thesis is to measure genome size of a sufficient amount of lichen mycobionts to be able to determine possible connection between genome size and ecology or functional traits of these lichen species. I succesfully measured the genome size of 50 lichen species using flow cytometry (FCM). I did molecular phylogenetic analysis of 141 taxa with known genome size in order to recognize the influence of phylogeny on genome size of these species. Two genes - ITS and mtSSU - were used for the phylogenetic analysis. Statistical analysis was performed using measured genome sizes, ecologicaly relevant traits of lichen species and my phylogenetic tree. I found that genome size might be connected to substrate preference, vegetative reproduction or the type of the lichens' photobiont. A correlation of genome size and life strategy - larger genome sizes connected to K-strategy, whereas smaller...
Changes in epiphytic lichen biota in the Czech Republic with emphasis on current situation
Hronová, Nikola ; Malíček, Jiří (advisor) ; Palice, Zdeněk (referee)
During the last two centuries a significant change of lichen communities has happened in the Czech Republic. Important factors which had influencing the lichen biota in the past and recently are summarized in this bachelor thesis. Acid rain caused by high imissions of SO2 a NOx was the most important factors of change of species and remaining acidification of substrates is still influencing lichen communities. Until the end of 80's of 20th century acid rain was a dominant factor influencing lichens. Afterwards, thanks to drop of its intensity in 90's of 20th eutrophication and availability of nitrogen in landscape became dominant influencing factors. All these factors mainly affected the communities of macrolichens, and especially cyanolichens to such an extent that some species in the Czech Republic became extinct. Recently the increasing availability of nutrients has been supporting the spread of nitrophilous species. Due to decrease of SO2 emissions to values from the end of 19th century some areas have been recolonized and some endangered species have returned. The transformation of lichen communities has also been significantly affected by forest management and land use. Based on changing climate and change of natural habitats a further decline mainly of suboceanic species is expected. A more...
Sheep grazing as a controversial tool of nature protection
Daňková, Tereza ; Malíček, Jiří (advisor) ; Sedláček, Ondřej (referee)
Sheep grazing is currently more and more used as a main type of management in protected areas. However, it seems that in many cases this type of management has a negative impact on a habitat or species of interest. This bachelor thesis try to demonstrate how a care about pastures in term of nature conservation should be applied in a selected area. There are examples of endangered species that are directly threatened by an unappropriate sheep grazing. Positive and negative influences of grazing, especially sheep grazing, are summarized.

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