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Vliv hlaváče černoústého (Neogobius melanostomus) na potravní řetězec řeky Ploučnice
STANĚK, Pavel
Biological invasions are prominent factor affecting changes in invaded ecosystems. Invasive species can alter in food web of the indigenous community, which leads to changes in the community through ecological and economic effects. This work was focused on the effect of the Round goby (Neogobius melanostomus, Pallas 1814) food web of river Ploučnice. Round goby was first recorded recently in the Czech Republic (2015). Thus, it can still be considered a young invader into Czech inland waters. The main goals of this thesis were: I) to reveal Round goby food source preferences, II) to Competition between Round goby and European bullhead (Cottus gobio, L 1758), as this species is a native endangered species present at this locality. III) Possible preferences of Round goby as a putative food source of predatory fishes in sampled localities. For this purpose, River Ploučnice has been chosen. River Ploučnice flows into Elbe River, which is fully invaded by Round goby. Thus, the bottom part of the Ploučnice River is invaded by Round goby as well. However, thanks to the presence of migratory barriers between localities, Round goby has not yet been detected in localities upstream. To reveal mention goals all biota units in all localities were sampled. Later, stable isotope analysis (carbon and nitrogen) followed by Bayesian models were employed. In general, results suggest that this species had the highest abundance among other species in localities with an established Round goby population. In addition, results reveal Round goby as a true generalist regarding food source preferences. Comparing trophic niche width and overlap showed a significant overlap between some of the ontogenetic groups of round goby and European bullhead, reaching up to 67,8 %. Also, increased niche overlap between ontogenetic stages of European bullhead was observed when Round goby was present, in comparison to localities without the presence of Round goby. Additionally, predatory fish food preferences showed no specialization on round goby as a food source, although round goby was part of their diets. In conclusion, this was found round gobyas a consumer, competitor, and even as a food source for predatory fishes.
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Problematika invazních druhů raků na území České republiky
Čuprová, Veronika
The diploma thesis following the bachelor thesis "Invasive species in the Czech Republic" is focused on the issue of invasive species of crayfish. The aim of the thesis is to describe the legislation, the current method of monitoring these species and the possibilities of their regulation. The thesis deals with the monitoring of invasive crayfish species at two selected sites in the Czech Republic and the application of appropriate regulatory interventions. Along with the monitoring, water samples were taken and analyses for the presence of crayfish plague were carried out. The results show that at the Prostřední rybník site, where the marbled crayfish occurs and where eradication measures have been underway since 2020, it has still not been completely successfully eradicated. From the interview conducted with local respondents, it was found that about half of the respondents are aware of this issue, thanks to the actions carried out to eliminate this species and the information boards posted in the area. In addition to the signal crayfish, a small population of the native endangered river crayfish is also present at Besének. Regulatory measures have also been implemented at this site in order to eliminate this invasive species as much as possible and to prevent potential threats to the native crayfish. Based on the results obtained, further possible control measures were proposed at both sites. In the future, more focus should be placed on education of this highly topical issue, as public awareness and understanding is considered one of the most effective preventive measures.
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Vegetace na zemědělské půdě v blízkosti železničních tratí
Vidrmertová, Ivana
The aim of this study was to monitor the vegetation, species distribution and percent cover of each species in an orchard adjacent to a railway line. Three sites were selected for observation, namely the orchard inter-row, the path in the orchard and the railway embankment. Vegetation was assessed by phytocenological photographs, of which 18 were taken, each covering 10 m2. The observations were carried out in July and September 2022. The data were processed by principal component analysis (PCA) and redundancy analysis (RDA). At the same time, the data were tabulated according to habitat and date of observation. Thirty-eight plant species were found during the assessment, and individual weed species representation was distributed into five groups according to habitat. Among the species assessed, five invasive species were found - Amaranthus retroflexus, Cirsium arvense, Erigeron annuus, Setaria pumila and Solidago canadensis.
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Hunting and fishing in the light of selected environmental issues
Rudolf, Vít ; Stejskal, Vojtěch (advisor) ; Sobotka, Michal (referee)
1 Hunting and fishing in the light of selected environmental issues Abstract The diploma thesis focuses on the hunting and fishing in the light of selected environmental issues. Both hunting and fishing are activities that may serve as freetime activities, but their main purpose is nature conservation and as such should respond to the changes in nature brought about by climate change. The aim of this diploma thesis is to provide the reader with a basic insight into the legal regulation of hunting and fishing and to assess the current legal regulation in terms of preparedness for the changes in nature brought about by ongoing climate change. The second objective is pursued by answering three questions: "Does the Czech legislation sufficiently care about biodiversity conservation?", "Does the Czech legislation effectively combat invasive and non-native species?" and "Is Czech legislation prepared for the changes in animal behaviour that will inevitably occur in the context of climate change?". The diploma thesis is divided into five chapters. The beginning of the diploma thesis focuses on the issue of climate change, where the emphasis is mainly placed on laying out the problems related to the loss of biodiversity, the introduction of non-native species and changes in animal behaviour. Next, the diploma...
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Aktivita raka signálního v podmínkách malého toku
DAVID, Jaroslav
The signal crayfish is one of the oldest invasive crayfish species in Europe, causing ecological and often economic damage in newly invaded locations. The invasion and associated problems can be monitored in real-time on the Křesanovský brook, where regular eradication measures have been carried out for six years. However, the detailed and comprehensive impact of these activities on the crayfish population as a whole and any changes in individual behaviour have not yet been studied in detail. To obtain relevant data for this purpose, this thesis video-recorded the situation in the stream in monthly cycles from May to September 2021, with recordings taken the night before and the night after thorough manual crayfish catching in the brook, evaluating the number and activity of observed crayfish. The results did not show that the trapping had changed the overall crayfish activity. Even with a high number of captured crayfish, the weakened crayfish population after trapping showed the same overall activity as the complete population before trapping (presumably due to an increase in individual activity in response to catching and accompanied habitat disturbance). Furthermore, the results underline the previously assumed low success rate of eradication efforts at the site and confirm that barriers in the stream are not sufficient to stop the signal crayfish spread. These findings will help to better understand the impact of eradication measures on signal crayfish populations. As this was the first research of its kind, this thesis opens up opportunities for methodological improvements and further development, as well as posing many new questions that need to be addressed. The ultimate goal of these efforts is to improve management interventions against invasive signal crayfish.
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The occurrence of herbaceous invasive plant species in the territory of Římov village
PETROVIČOVÁ, Ivana
The diploma thesis is focused on the occurrence of herbaceous invasive species in the urban area of Římov village with a possible connection to the open landscape. As part of the monitoring, 14 invasive species included in the black and gray list of the Czech Republic were found in the area. Among the species associated mainly with the urban environment were, for example, Conyza canadensis, Erigeron annuus, Oxalis corniculata, Galinsoga parviflora and G. quadriradiata. In the (semi) natural environment, for example, the species Reynoutria japonica, Impatiens parviflora or Helianthus tuberosus were observed. The occurrence of selected invasive species is shown in the map data. The diploma thesis also includes a botanical determination key.
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Population trends, threats and conservation of island endemic birds
Rohová, Kateřina ; Reif, Jiří (advisor) ; Sam, Kateřina (referee)
As endemics are considered plant and animal species including birds, which are in the focus of this thesis, that are found in a restricted geographic region and nowhere else in the world. Such endemics typically occur on the islands that are often recognized as important global biodiversity hotspots. However, many endemic species are very vulnerable due to numerous factors (mainly genetic and demographic) closely linked to the way of life on the islands. Huge effort is dedicated to their conservation, and it thus reasonable to ask whether such an effort made a significant contribution to prevent their loss. Here, I evaluate the overall success of island bird endemics conservation compared to continental conditions because such a global analysis has been lacking up to now. In addition, this thesis examines how three major threatening factors (namely habitat destruction, invasive species, and overexploitation) driven by anthropogenic activities affect population trends of continental and island bird species. Finally, I mapped and explained, using examples, which conservation tools are effective for supporting the populations of island endemic species. The results of statistical analyses, based on a global dataset containing almost 8000 avian species, showed that island endemic species are more...
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