|
|
Allelopathy of aquatic plants and its possible application to control cyanobacterial blooms
Kolářová, Anna ; Jandová, Kateřina (advisor) ; Kučerová, Andrea (referee)
The excessive growth of phytoplankton and the development of water bloom leading to the damage to aquatic ecosystems are becoming a more and more frequent problem. There are many methods to control the water bloom from which mainly those that use interactions of living organisms have been developing lately, with the utilisation of aquatic plant allelopathy being one of them. Allelopathy is a type of relationship between two organisms when one of them influences the other by secreting allelopathically active compounds in the environment. However, the effect of these secondary metabolites depends on many biotic and abiotic factors, which also has consequences for their potential use to control the water bloom. Although the results of many studies suggest that allelopathy can affect the community of phytoplankton, its role in aquatic ecosystems is still unclear. This thesis summarizes the knowledge about the occurrence of allelopathy among aquatic organisms, the modes of action of allelochemicals and the impacts of the key factors influencing the allelopathic effect. At the same time, it evaluates the prospects of using the allelopathy of aquatic plants to control water bloom and reviews experimental approaches to studying allelopathic interactions.
|
|
|
The effect of salting the highway D8 in the winter months: Results of species composition and abundance of water organisms in streams during vegetation season in year 2018.
Blabolil, Petr ; Kučerová, Andrea ; Matěna, Josef ; Rychetský, P. ; Peterka, Jiří
The focus of the study is to document the effect of chloride toxicity on aquatic organisms (macrophytes, aufwuchs, macrozoobenthos, fish and amphibians) in recipients around the D8 motorway, km 48.276 - 64.689, where the motorway passes through the České středohoří Protected Landscape Area. The summary of the achieved results for the vegetation season 2018 is the content of the presented report.
|
|
|
The effect of salting the highway D8 in the winter months: Results of species composition and abundance of water organisms in streams during vegetation season in year 2019.
Blabolil, Petr ; Kučerová, Andrea ; Matěna, Josef ; Bešta, Tomáš ; Rychetský, P. ; Peterka, Jiří
The focus of the study is to document the effect of chloride toxicity on aquatic organisms (macrophytes, aufwuchs, macrozoobenthos, fish and amphibians) in recipients around the D8 motorway, km 48.276 - 64.689, where the motorway passes through the České středohoří Protected Landscape Area. The summary of the achieved results for the vegetation season 2019 is the content of the presented report.
|
|
|
Habitat preferences of the members of the family Chydoridae (Crustacea, Cladocera)
Zimová, Tereza ; Sacherová, Veronika (advisor) ; Šorf, Michal (referee)
This thesis is a literature review of ecological niche of some species of Cladoceran family Chydoridae. The aim of this work is to summarize the knowledge about the occurrence of species in various types of environments and what are their preferences or see which factors are limiting for them. This work is focused on the type of habitats in which they are found, the trophic state of water and pH. It also mentions to a lesser extent environmental factors such as concentration of calcium and water depth, which might also influence the niche choice of these species. Species can be divided into opportunists with a wide niche and specialists with a narrow one, yet a large proportion of species have a wide tolerance to most environmental factors. Key words: Chydorids, niche, habitat, macrophytes, open water, pH, trophic state, depth, calcium
|
|
|
Distribution of herbivorous fish is frozen by low temperature
VEJŘÍKOVÁ, Ivana
The number of herbivores in populations of ectothermic vertebrates decreases with increasing latitude. At higher latitudes, fish consuming plant matter are exclusively omnivorous. We assess whether omnivorous fish readily shift to herbivory or whether animal prey is typically preferred. We address temperature as the key factor causing their absence at higher latitudes and discuss the potential poleward dispersion caused by climate changes. A controlled experiment illustrates that rudd (Scardinius erythrophthalmus) readily utilize plant matter at water temperatures above 20 °C and avoid its consumption below 20 °C. Field data support these results, showing that plant matter dominates rudd diets during the summer and is absent during the spring. Utilizing cellulose requires the enzyme cellulase, which is produced by microorganisms growing at temperatures of 15-42 °C. Water temperatures at higher latitudes do not reach 15 °C year-round; at our latitude of 50°N~150 days/year. Hence, the species richness of omnivorous fish decreases dramatically above 55° latitude. Our results provide support for the hypothesis that strict herbivorous specialists have developed only in the tropics. Temperatures below 15 °C, even for a short time period, inactivate cellulase and cause diet limitations for omnivorous fish. However, we may expect increases in herbivory at higher latitudes caused by climate change.
|
|
|
Floristic and mollusco-vertebratological survey on four localities of the blind branches of Blanice river close to Milenovice, Myšenec, Protivín and Vitice. Floristic and mollusco-vertebratological survey on seven localities of the blind branches of Blanice river close to Čejetice, Krašlovice, Skály u Protivína, Slaník and Žďár u Protivína
Kučerová, Andrea ; Čtvrtlíková, Martina ; Blabolil, Petr ; Muška, Milan ; Peterka, Jiří
The aim of the study was to investigate occurrence of aquatic and wetland macrophytes, large water molluscs and vertebrates, and assessment of the effect of planned actions on species composition and protective measures of endangered species
|
|
|
Growth of aquatic vegetation in fish ponds used for recreation - Bolevecká soustava near Plzeň.
Pták, Martin ; Duras, Jindřich (advisor) ; Potužák, Jan (referee)
The aim of this diploma thesis was to clarify the differences among three different ponds (Bolevecký, Třemošenský, Šídlovský) situated in Pilsen. All of the above mentioned ponds are recreational areas where Bolevecký pond is best known for his water quality improvements since 2006 (after application of Fe and Al - colagulants and also fish - stock changes). The main difference was based on the growth of submersed water plants. The macrophytes were growing slowly or not at all in Bolevecký pond. There was a huge expansion of macrophytes (mainly Myriophyllum spicatum species) in Třemošenský and Šídlovský ponds therefore the water plants must be regulated during summer seasons by mechanical harvesting. The water in all three ponds proves the same qualities but the differences may be found in the nutrient composition of sediments. The fractionation analysis (the founders Psenner and Puczsko) confirmed the fact that all localities are poor in phosphorus however the differences were found in content of iron. The increased content of iron was observed in sediments of Šídlovksý and Třemošenský ponds (mainly in BD fraction - the iron was unstable under redox potential changes). The result of this analysis proves that phosphorus is potentially more available for macrophytes in sediments of Třemošenský and Šídlovský...
|
|
|
Problems of water quality and ecological potential of Lipno Reservoir in the period 1991-2012
Hejzlar, Josef ; Galindo, F. ; Krolová, Monika ; Znachor, Petr ; Žaloudík, Jiří
The research report describes the analysis of trends in water quality, external and internal nutrient loading, and apportionment of nutrient sources in the Lipno reservoir on the River Vltava, Czech Republic, during the period 1991-2012, together with a prognosis of future trends of eutrophication and possible management mitigation measures for improvement of the reservoir´s ecological potential to achieve compliance with the EU Water Framework Directive.
|
|
| |
|
| |
guest ::
