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The role of stream-corridors for the speading of invertebrates in the landscape
Ratajová, Michaela ; Juřičková, Lucie (advisor) ; Čejka, Tomáš (referee)
The characteristic environment along riverbeds forms corridors, which can be used by numerous organisms for their dispersion - stream corridors. Water is a useful medium of transportation, especially for the species with low dispersion abilities, such as annelids, molluscs and several arthropods. The terrestrial animals nearby the water flows are often adapted to the survival in the water. They are able to survive short term inundation, or reproduce very quickly to renew their abundances. However, well documented cases of the species spreading along the rivers are rather rare. Most of them are molluscs species. The banks of the Vltava, Berounka or Sázava rivers are colonized by the snail Arianta arbustorum. There is evidence of the spreading of annelids along some European rivers. Such examples, together with the various adaptations to survival of inundation suggest that the stream corridors really work as a spreading device.
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Mollusc grazing and secondary metabolites of lichens
Černajová, Ivana ; Svoboda, David (advisor) ; Vondrák, Jan (referee)
In contrast to the much that is known about herbivory and its consequences, lichenovory has seldom been studied. Recently, studies confirming the anti-feedant role of lichen secondary metabolites were brought out and hypotheses considering the nature of these interactions were introduced. Also, a few papers dealing with the ecological consequences of lichenovory were published lately. My thesis was aimed on the secondary metabolites issue and the preferences of the lichen feeders in the natural conditions. Six epiphytic lichen species containing secondary compounds (Parmelia sulcata, P. saxatilis, Parmelina tiliacea, Melanelixia glabratula, M. subaurifera, M. glabra), two without them (Melanohalea exasperata, M. exasperatula) and two species of gastropods that naturally climb the trees to feed on lichens (Lehmannia marginata, Cochlodina cerata) were selected for grazing experiments. The deterring role of the lichen compounds was proven. These were also identified using thin-layer chromatography. Subsequently, a transplantation experiment was carried out. It was focused on specifying the preferences of lichen grazers in their natural habitat. The genus Melanohalea that does not contain any secondary metabolites was strongly prefered. No significant preferences among the other species used in the...
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The influence of geology to the diversity of molluscan assemblages
Krajinčáková, Lucie Linda ; Juřičková, Lucie (advisor) ; Myšák, Jan (referee)
Molluscan populations are influenced by various factors of environment where they occur. In my work I am taking particular atention of soil properties, which are directly influenced by the geological substrate, and of course other factors which are with soil properties either directly or indirectly related. The important benchmarks are especially moisture, pH, calcium content and vegetation cover. This bachelor thesis also deals with utilization of calcium salts. Geological substrate is closely linked with the diversity and abundance of molluscan populations. Various pedochemical factors affect molluscan communities whether it is the amount of calcium in the soil or a pH value. In the past different authors found different dependencies between environmental factors, species composition and diversity of molluscan communities. Most of the studies were focused on very specific habitats and locations. In this thesis I tried to organize our knowledge about the specific effects of various environmental factors, especialy compositíon of geological substrate on malakofauna. Key words: Mollusca, Gastropoda, Geological substrate, diversity
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Succession of mollusk assemblages in quarries of Bohemian Karst
Kocurková, Alena ; Juřičková, Lucie (advisor) ; Horsáková, Veronika (referee)
Molluscan succession was studied in 18 abandoned limestone quarries of different age in Bohemian Karst. The number of species in studied quarries increases in the time. The less species were found in the oldest quarries. This trend was probably caused by habitat diversity decline although it is not conclusive. The best predictors of mollusk species composition are type of surrounding vegetation, light and the cover of tree layer. It is important to take into account correlations of the other environmental variables with light and the cover of tree layer. Compositions of mollusk assemblages of north and south-facing slopes differ, but these differences diminish with ongoing succession. Quarries represent suitable model sites for the study of succession.
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Comparison of mollusc fauna from selected natural reserves on southern Moravia
Bohatá, Lucie ; Vrabec, Vladimír (advisor) ; Jan, Jan (referee)
In this thesis is compared mollusc fauna of six protected areas on the south of Moravia, with characteristic and appraisal of their condition. These protected areas belong to control of BR Lower Moravia and almost all of them belong under control of CHKO Pálava: NPR Cahnov Soutok, NPR Křivé jezero, NPP Pastvisko u Lednice, NPR Ranšpurk, NPR Slanisko u Nesytu, EVL Trkmanské louky. Tested hypothesis was, whether reserves with prevailing of forest cover evince richer faun compare to reserves with prevailing of open space.
Mollusc fauna was collected by individual picking with the aid of flush solid material through strainer and off take of forest soil. Subsequently collected material was inspected in detail, sorted out and determined.
Information about discovered species was compared with the aid of Simpson´s index of domination and Jaccard´s index of similarity and recorded to tables. The biggest index of diversity has NPR Ranšpurk and the lowest has NPR Slanisko u Nesytu according to Simpson´s index. It means that community of molluscs from NPR Ranšpurk is covered same amount of specimen determined species, while on NPR Slanisko u Nesytu was discovered dominance of vulnerable species Anius spirobis (Linné, 1758). According to Jaccard´s index of similarity is the most similar (31%) reserve NPR Křivé jezero and NPR Slanisko u Nesytu and the worst similar (8%) are reserves NPP Pastvisko u Lednice and EVL Trkmanské louky.
Hypothesis was confirmed on the grounds of number of species determined on collected stations and Simpson´s index with bigger diversity on reserves with prevailing of forest cover. According to Jaccard´s index of similarity are forest areas and open areas similar with 66%. The high similarity is consequence of abiotic factors, which influence inspected areas in reserves.
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Mollusca of the Czech Republic
Rindtová, Dita ; Hlava, Jakub (advisor) ; Křivská, Daniela (referee)
The Bachelor work Mollusca of the Czech Republic deals with basic information about molluscs occurring in the Czech Republic. In the research part of my work I deal with the anatomy of their bodies, shells and life cycles characteristic for the main representatives. In general characterization the work mentions endangered species listed in the Red List. Furthermore, the research part deals with ecology focused on shellfish incidence depending on the conditions of the ecosystem, introduction, and the methods of mollusc importance to humans.
The aim of the practical part was a faunal survey of selected localities contaminated by a man. This research was carried out in selected localities near the town of Příbram. It was the firsta research focused on the incidence of molluscs in these areas. The methodology of sample collection was carried out according to common methods of collecting molluscs and it is more specified in the work.
The own research was focused on characterisation of the areas (5 localities) where the collection was carried out. Thus there was formed a systematic overview of acquired kinds of terrestrial representatives according to designated habitats, taxonomic classification and specific characterisation of the species. A total of 514 individuals were processed belonging to 26 species of molluscs. The most numerous family had Vrásenkovití (Discidae) where the number of representatives climbed to 82 individuals. On the contrary Oxychilidae family, Skleněnkovití (Vitrinidae) and Melampovití (Ellobiidae) occured the least. There was found only one individual of each family.
In the last part of my work I deal with comparison of my research to the previous research carried out in Kokořínsko Reserve. This area has similar climatic conditions and the features of the ecosystems. The result of the comparison corresponds to the variability of the species found here.
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Molluscan fauna of the Czech Republic
Cermanová, Michaela ; Hlava, Jakub (advisor) ; Husák, Tomáš (referee)
This thesis deals with the problems of molluscs on the area of the Czech Republic.
The introduction characterizes the tribe of molluscs and its history. The following part focuses on the morphology and anatomy of terrestrial and water molluscs, their ecology and biology. There is a detailed description of the life cycle of snails and clams, their way of life and food. The character of spread on the area of the Czech Republic and their migration connected with settlement of new biotopes was described at water molluscs. The following chapter deals with the question of collection and identification of molluscs, it describes several methods of collecting and identification of terrestrial and especially water molluscs.
A big part of the thesis is devoted to endangering of the mollusc fauna and negative influence of people on the malacofauna by creating new conditions in the landscape. The negative influences, by which people significantly change the landscape character, include for example forest clearing, construction of dams or longitudinal stream regulation. The last chapter describes the unoriginal species of terrestrial and water molluscs on the area of the Czech Republic, which represent another danger for our original malacofauna.
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