National Repository of Grey Literature 237 records found  beginprevious100 - 109nextend  jump to record: Search took 0.01 seconds. 
Use of nanomagnets treated materials in study of decomposition
Vyhnálek, Michal ; Frouz, Jan (advisor) ; Veselá, Hana (referee)
In study of soil organic matter, many methods of carbon labeling are used, mostly using carbon isotope 13 C, which are reliable, but require expensive devices. Magnetic nanoparticles could provide low-cost alternative, which can be prepared in most laboratories with basic equipment. The upside of nanoparticles usage is the fact, that we could monitor fate of individual particles added to soil, including their chemical transformations or changes in microbial communities. The goal of this paper was to test the usage of magnetic nanoparticles and prove the reliability of carbon labeling through experiment. KEY WORDS Magnetic nanoparticles, decomposition, soil organic matter
The growth of leguminous plants during primary succession in post-mining sites
Zedníková, Petra ; Frouz, Jan (advisor) ; Mudrák, Ondřej (referee)
Post-mining sites are characterized by unfavorable conditions limiting the rapid development of natural vegetation, which is particularly low nitrogen in the soil. Plants with symbiotic nitrogen fixation can be used for reclamation these degraded areas because they increase the nitrogen content in soil and accelerate the primary succession on the dump. The aim of this study was to evaluate the growth of three species of plants of the family Fabaceae, namely red clover (Trifolium pratense), bird's foot trefoil (Lotus corniculatus) and bird wetch (Vicia cracca), in differently old soils from dumps that were reclaimed and compare them to the growth in soils from areas that developed by spontaneous succession. Furthermore, to compare the changes in the growth of these species of plants in a situation where they grew separately in the soil compared to the growth in competition with grass (Poa compressa). Another aim was to evaluate the influence of the growth of these plants on soil properties during primary succession on the basis of measurement of various parameters in soil. The mentioned species of plants were sown into the sifted soils taken from the Velká podkrušnohorská výsypka after brown coal mining near Sokolov. The growth took place in a greenhouse for 5 months. Subsequently, above-ground and...
Autotrophic and heterotrophic soil respiration
Kopecký, Tomáš ; Frouz, Jan (advisor) ; Kukla, Jaroslav (referee)
The goal o f this study is to describe autotrophic and heterothrophic respirat io n on mine heaps near Soko lov (Czech Republic) through literar y research and a o ne year lo ng research on mine heaps. Resu lts show that the temperature and sit e difference have stat ist ica lly significant impact on respirat io n, however, at temperatures around 0 degrees celsius, there were significant increases in respiratio n on unrec laimed sit es. This pheno meno n needs to be explored by furt her research for our understanding o f natural succession dyna mics on mine heaps. Temperature was not statist ically significant for respirat ion o n unrecla imed sit es. That po ints to limit at ion o f respirat ion by another factor.
Soil water regime of reclaimed and unreclaimed post mining heaps
Cejpek, Jiří ; Frouz, Jan (advisor) ; Moldan, Bedřich (referee) ; Tesař, Miroslav (referee)
This PhD thesis compares the water regime of reclaimed and unreclaimed spoil heaps after brown coal mining, with special regard to the development of hydrological properties of soils, which are determinant for the movement and retention of water in the soil. The basic influence on the supply of soil water has the technology of pouring the spoil heaps and aging, which co-regulates the development of vegetation. During the development of soil's spoil heaps increases field water capacity and water retention, but also increases the wilting point. These changes are related to the accumulation of organic matter in the soil and the degradation of claystones to particle size of physical clay. The development of the ability of the spoil heaps soils to bind water is greater in reclaimed areas, where the upper organomineral horizon develops more rapidly, but there is also a wilting point and water consumption. On unreclaimed area, the soil substrate develops more slowly. Overall, the differences in water regime between reclaimed and unreclaimed areas are small.
Wood ant thermoregulation heat cluster formation
Slováková, Jana ; Frouz, Jan (advisor) ; Kadochová, Štěpánka (referee)
This study focuses on the influence of ant clusters on nest thermoregulation. The significance of this influence has been measured using temperature information from dataloggers about inner nest as well as ambient air temperature during the period from April 4 to June 4, 2016 and images capturing the ant mound surface for the same period. The results show that the ant clusters incidence rate and the size of the clusters are significantly affected by the inner temperature of the nest. The dependence of the cluster occurrence on the inner temperature is not linear but rather has the character of steep drops at defined temperature thresholds. In the temperature range of 0 - 7řC cluster occurrence significantly increases and reaches the occurrence peak at the upper limit of this interval, from 7řC to 21řC the cluster occurrence rate is significantly lower but relatively constant and at the temperature above 21řC there is a steep decrease. The occurrence of clusters is also significantly determined by climatic influences and insolation, with the measured data showing that after a precipitation or snowfall, the average cluster size is significantly larger compared to similar days without a precipitation or snowfall recorded. Keywords: Formica polyctena, thermoregulation, nest, temperature, ecology
Synanthropic arthropods as a producers of allergens in households
Smetanová, Ivana ; Hubert, Jan (advisor) ; Frouz, Jan (referee)
This work is about arthropods producing allergens in our homes. It sums together not just todays knowledge about allergic effects in human environment and possible diseases, but also about behavior, occurrence and life cycle of species themself and about possible elimination arthropods and allergens from our households. Most of the world population is nowadays affected by the allergies, allergens are all around us. In today's world when people spend most of the time in the interior enviroment whitch contains allergens and their sources, are also important allergic diseases caused by the arthropods, which we share our homes with. Almost in every room in our home are present some of the arthropods producing allergens. These allergens can affect the life of sensitive persons. Allergens are inside the body of the arthropods and in their body secretions. The highest volume of allergens coming from arthropods in our homes is contained in a dust and food. Allergic reaction is caused by consummation, inhalation or body contact. The cheapest and the most effective treatment of the allergic diseases is to avoid the allergens. The best what we can do is to regulate their volume in our households, because the complete elimination is practically impossible. Key words: Allergens, synanthropic arthropods, households
Soil water retention in the landscape
Hřebejková, Barbora ; Šípek, Václav (advisor) ; Frouz, Jan (referee)
Water retention in the landscape is one the current topics in environmental protection. It is affected by a number of factors and is changing both in time and space. The goal of this thesis is to examine the long-term development of water retention in the landscape and to determine the influence of different types of vegetation on the soil moisture underneath. In the first part of my thesis I review different soil types with respect to their physical characteristics and interaction with water, and ways of measuring soil moisture. The aim of the thesis is the sum up the basic knowledge about soil and basics behaviour, mainly in the relation with soil moisture. There are introduced methods of soil moisture measurement with regard to their limits. In the second part I focus on analysis of selected studies covering the topic of water retention in the landscape. Due to the technical difficulty is only a few studies devoted to a long term measurement of soil water by direct methods and therefore are results mostly limited to evaluate soil water retention by hydropedological models. In the final part I discuss and evaluate the results of the aforementioned studies. Key words: water retention, soil moisture, evapotranspiration, soil hydrology, climate change
Post-mining lanscapes, and the dynamics and distribution of soil faunal succession
Moradi, Jabbar ; Frouz, Jan (advisor) ; Šarapatka, Bořivoj (referee) ; Seeber, Julia (referee)
Post-mining landscapes, and the dynamics and distribution of soil faunal succession M.Sc. Jabbar Moradi Abstract Soil biota play an essential role in ecosystem services provided by soil. Here we studied some of the factors affecting soil biota colonization, distribution, biodiversity and conservation values, and their impact on plants' interactions, in reclaimed and unreclaimed (spontaneous succession) post mining sites, located in the spoil heaps after coal mining near Sokolov, Czech Republic, which was summarized in four research papers. Transplant of soil blocks show that despite abundant soil fauna communities in the blocks, they migrate little into surrounding sites, which indicate that access to the disturbed surfaces does not guarantee a successful colonization in the post mining sites where a new soil profile is to be developed. Studying the heterogeneous distribution of fauna under various vegetation patches and sites, we showed that different faunal (i.e., microbial, meso, and macrofaunal) groups' distribution heterogeneity could be partly explained by different explanatory factors and using one set of factors for all the groups would not be powerful enough to create a short-list of the influential elements for each of the faunal groups. Investigating the importance of microtopography, in our...
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....

National Repository of Grey Literature : 237 records found   beginprevious100 - 109nextend  jump to record:
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