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The influence of habitat structure on aquatic beetles in southern Bohemia
KOLÁŘ, Vojtěch
I studied the influence of fishpond management and environmental characteristics on diving beetles (Coleoptera: Dytiscidae), which are important predators in aquatic systems. In 2014 I used live traps to study diving beetle communities in 117 ponds in South Bohemia. The ponds were divided in three categories: intensively managed, extensively managed, and without fish. In total 26 species of diving beetles were found (N=1346). Overall, the beetles prefered shallow litoral zones with cattail (Typha), manna grass (Glyceria) and reed (Phragmites). The number of species declined with increasing alttitude and depth near the trap, while their abundance increased with pond area and amount of detritus near the trap. Beetles occured more in ponds with lower pH, lower conductivity and higher oxygen content. More beetles were found in fishless ponds. On the other hand, some ponds with high density of fishes but well preserved littoral zone had similar communities of diving beetles to the fishless ponds. This shows that high density of fish in ponds decreases the diversity and abundance of diving beetles, most likely because it decreases the vegetation in littoral zone. During the survey, four new localities of Graphoderus bilineatus were found; the species is protected by NATURA 2000 and has been known from very few recent localities in the Třeboň area.
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Applications of experimental mineralogy to Te containing systems: Crystal structures, phase relations
Laufek, František ; Rieder, Milan (advisor) ; Palatinus, Lukáš (referee) ; Johan, Zdeněk (referee)
This dissertation contributes to the crystal chemistry of Te. The primary goals of the thesis are synthesis and crystal structure analysis of new Te-bearing ternary phases. The first part of the thesis shows significance of experimental mineralogy in research of Te containing systems. It briefly describes a novel approach to the study of new mineral species - the possibility of using synthetic analogues for their detailed mineralogical characterization. The results of the experimental mineralogical study in the Ni-Sb-Te ternary system at 400řC are reported in the second part. According to the performed experiments, two solid solutions λ1- Ni(Sb1-xTex)1+y (0<x<1, where 109.09.0 ≤≤⇒≥≈∀ yx ) and λ2 - NiSb1-xTe2x (0.28<x<0.66) dominate the system at 400řC. A characteristic feature of most phases present in the Ni-Sb-Te system at 400řC is apparent tendency to the Sb - Te substitution. The third part deals with the characterisation of the new mineral pašavaite Pd3Pb2Te2, which was found at the Noril'sk-Talnakh Ni-Cu camp, Russia. The synthetic Pd3Pb2Te2 phase was used for thorough mineralogical characterization of this new mineral species. Pašavaite displays orthorhombic symmetry, space group Pmmn. The structural identity between natural grains and synthetic Pd3Pb2Te was supported by the EBSD study. The...
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DEVELOPMENT OF ICHTIOFAUNA IN THE NEW FILED POND CHABAŘOVICE
ŤUK, Josef
The Chabarovice coal mining pit arose by flooding the former strip mine area for brown coal. After filling, the pit area should reach about 225 hectare, total volume of water 34.4 mil. m3, average depth 15,6 meters with maximum of 23,3meters. It is assumed that the pond and adjacent areas will be used for recreation usage after completion of recultivation and ground shaping. I have performed the investigations in June and in August 2004 - 2005, using basic ichthyological methods. The data about recruitment were collected by the littoral seine net and adult fish (older than one year) were investigated by gillnets nets. Fish was determinated to genus, individually measured by slide caliper (fry) and by measuring plate (adult fish). The lenght of fish body (SL-standart lenght) was measured in millimeters and fish were weighted separately (W v g). In the year 2005, also scales were taken from individual fish for the age assesment. Obtained data were processed with regard to performed biomanipulation measures in individual sectores. Nine fish species and one hybrid were recorded by the monitoring with gillnets nets. The most numerous fish were juveniles and adults of rudd with SL 74 {--} 300 mm and the weight up to 618 g. The fish species with the strongest impact upon the pit ecosystem function is conitnuously the perch with the dominance of individuals with SL 46 to 337 mm and weight zup to 850 g.
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Effect of management on three moss species of fen meadows (Breidleria pratensis, Sphagnum warnstorfii, Tomentypnum nitens)
VELEHRADSKÁ, Tereza
Effects of different types of management (control, mown, mown + disturbed (gaps) + litter removed) on three moss species of fen meadows were studied. Experimental plots were established at sixteen sites in the Bohemian Forest, in the foothills of the Bohemian Forest and in Českomoravská vrchovina. Relevés and micromaps of bryophytes in the plots 0.5 × 0.5m were sampled at the beginning of the experiment during the summer season of 2010 and then after 3 seasons (during the summer season of 2012) of performing management. The age of the abandoned meadows was also determined and values of pH, conductivity and height of water level of each plot were measured. Positive influences of both types of management on the cover of Tomentypnum nitens and of management with creating gaps and remowing of litter on the cover of Breidleria pratensis were significant. Effect of management on the Sphagnum warnstorfii was significant only when processes of remaining on already occupied places and the expansion to new places were tested separately. Enviromental values did not significantly influence the change of cover of any species between 2010 and 2012. In conclusion, it is clear that diverse management with reasonable use of these practices (mowing, creation of gaps, litter removal) is desirable for maintaining of vital and diverse bryophyte layer.
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CIRCADIAN GENES AND REGULATION OF DIAPAUSE IN INSECT
BAJGAR, Adam
This thesis considers various roles of circadian clock genes in insect physiology. Application of molecular-biology methods in Pyrrhocoris apterus, non-model insect species, enable us to investigate involvement of circadian clock genes in photoperiod induced physiological responses. We discover involvement of neuroendocrine cells, and a role of Juvenile hormone (JH) signalization in transduction of photoperiodic signalization to peripheral tissues. We found new principles of JH signal diversification in tissue specific manner, and in addition described molecular mechanism of photoperiod induced changes in gut physiology. Comparison of gut and fat body tissue reveals that mechanism observed in the gut is tissue specific, and that circadian clock genes exhibit tissue specific functional pleiotropic effect.
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Palingenia longicauda (Olivier, 1791) (Ephemeroptera, Palingeniidae): Do refugia in the Danube basin still work?
Soldán, Tomáš ; Godunko, Roman J. ; Zahrádková, S. ; Sroka, Pavel
Palingenia longicauda (OLIVIER, 1791), a well-known species of mayfly belongsto the most critically endangered species of the Ephemeroptera in Europe. It represents the Pontic faunistic element of the expansive type originally distributed in almost all great and numerous middle-sized European rivers in Austria, Belgium, Bulgaria, Czech Republic, France, Germany, Hungary, Macedonia, Poland, Rumania, Slovakia, Ukraine and Yugoslavia. At present, the species is extinct or at least missing at most of its original area except for relatively small refugia in the Tisza basin in Hungary and probably also Slovakia and Ukraine. Distribution of P. longicauda is discussed and a new subarea in the Danube delta in Rumania (locality near Murighiol, stretch of the Bratul Sfintu Gheoghe) is documented for the first time. The nature of a new occurrence is discussed – it might represent either a new, still unknown refuge and/or recovery of the original population(s) caused by downstream drift.
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Energetic usage of grasses
BERNAS, Jaroslav
Renewable sources of the energy are still more important topic. And the reason is that the biomass is already one of the future energy sources for the Czech Republic. Percentage of the biomass for the purposes of the energy should be increase after some time. This progressive using of the biomass will be accompanied by the searching of the new procedures for the acquisition processing and utilization. The aim of my bachelor thesis was the valorization of the usefulness of the concrete kinds of grass for the cultivation and for the purposes of the energy and focus on their productive power. The literature review is focused on the selected energy resources which are previously used in the ČR, including the fossil fuels and energy sources used optional, energy and water, wind and biomass. Furthermore, on the botanical characteristic of selected grass species (Phalaris arundinacea L., Arrhenatherum elatius L., Dactylis glomerata L.) and mainly on their agro-technical requirements. The field experiments were established for selected types of grass and on the basic of results acquired from the cultivation were drawed the conclusions which substantiate the agro-technical steps.
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