|
|
Habitat selection by dragonflies - effect of littoral and riparian vegetation
Bonková, Anita ; Černý, Martin (advisor) ; Waldhauser, Martin (referee)
Dragonflies form one of the important pillars of most aquatic ecosystems and play an important role in maintaining their balance. The main goal of this bachelor's thesis is to summarize current knowledge about the habitat preferences of members of the order Odonata, with a focus on the effect of littoral and riparian vegetation, which are critical components of aquatic biotopes and significantly influence the distribution, abundance and reproductive success of dragonflies. In my work, I focus on all developmental stages, from larvae to adults. These findings are important for the maintenance and revitalization of freshwater ecosystems, in which it is necessary to pay attention to the composition of littoral and riparian vegetation to support the diverse needs of this unique insect order. Key words: habitat preference, dragonflies, Odonata, riparian vegetation, littoral vegetation
|
|
|
Aquatic insect assemblages in littoral zones of ponds and other man-made habitats
KOLÁŘ, Vojtěch
This thesis focuses on aquatic insect and newt assemblages in fishponds and other man-made standing waters. It reviews the effects of fishpond management and restoration of post-mining sites on main aquatic taxa, with main focus on aquatic insects in the littoral zone. The next five chapters deal with long-term changes of the littoral habitats in fishponds and with various aspects of the importance of littoral habitats for aquatic organisms, mainly predatory insects and newts. The results are used to recommend management approaches aimed to increase biodiversity and conservation value of fishponds and other man-made habitats.
|
|
| |
|
| |
|
|
Factors affecting the occurrence of aquatic macrophytes in the Lipno reservoir
KROLOVÁ, Monika
This RNDr. thesis focuses on the species composition and cover in the littoral of the Lipno Reservoir in 2006. Aquatic macrophytes are an essential component of littoral communities in lakes. Their reasonable development positively affects biodiversity and stability of the aquatic ecosystems and water quality. The aim of this study was to characterise the development of littoral macrophytes in Lipno Reservoir, an artificial lake with seasonal water level fluctuation, and highlight controlling factors for macrophyte occurrence. The development of macrophytes was examined at 114 segments of the shoreline, each 50 m long, situated along the whole reservoir perimeter in regular 1km distances. The segments were surveyed for phytocenology, shore morphology, pedological characteristics of substrate, and anthropogenic impact. The survey identified 53 macrophyte species (24 hydrophilic terrestrial, 17 emergent,1 floating-leaved, 2 free-floating, 4 submersed, and 5 amphibious). The average vegetation cover of the examined segments was 14 %, with approximately one third of the segments without any macrophytes and another third with vegetation cover less than 10 %. Macrophytes occurred only in the uppermost eulittoral zone down to the level of 75 % probability of water surface exceedance. On the basis of a correlation analysis, the major factors affecting macrophyte occurrence in the littoral zone were shore morphology, light conditions in water and erosion effect of waves that together with water level fluctuation caused loss of fine particles from and degradation of the substrate in the littoral zone.
|
|
|
Impact of land use on the former sand-pits in the region of Veselí nad Lužnicí
NOVÁK, Ondřej
Sand-pits which were formed especially in the floodplain of the Lužnice River since the 1950s currently constitute important landscape element of the Třeboň Basin. My diploma thesis is focused on the assessment of the impact of land use on the former sand-pits in the region of Veselí nad Lužnicí. Field investigations were carried out from the beginning of June till the end of August 2008. I mapped the land use of this area by using a map key. I put down particular areas {--} agricultural areas, forest areas, water areas, bild-up areas, other areas {--} into map photographs. The total area of the mapped territory was 989 hecteres. The biggest part of the area comprises of forest growths and field-grown plants. Water areas (with the main element of the mapped area {--} a system of former sandpits) formed 23% of the total area. On the bank sof the sand-pits were placed phytosociological relevé, which illustrated littoral vegetation and environment in which this vegetation is located, and what is the influence of human activity on vegetation. I placed 74 phytosociological relevé in this system. I recorded 125 plant species {--} out of these were 104 herb plants and 21 woody species. I recorded 41 nitrophilous, 52 wetland, 16 ruderal and 2 stronngly endangered species. Altogether, 20 water samplings were carried out. Horusice I sand-pit is the richest in nutrient, the poorest in nutrients is Horusice sand-pit.
|
|
|
Nová metoda vzorkování fytofilních bezobratlých ve vynořené litorální vegetaci
Sychra, Jan ; Adámek, Zdeněk
The aim of the study was to design the sampling method for collection of phytophilous macroinvertebrates associated with submersed parts of hard emergent littoral vegetation in still waters, which will join technical sampler unpretentiousness, sampling simplicity and maximal quantitative accuracy. For these purposes, we developed a modified Gerking´s frame box sampler with movable cutter for sampling of animals in the littoral macrophyte beds and a new type of core sampler for collection of animals inhabiting the root zone of emergent plant beds. Both sampling devices are suitable for studies targeted on macroinvertebrates monitoring. The comparative sampling using frame box sampler and benthos handnet was performed in the littoral of three carp ponds. The sampling procedure utilizing the frame sampler was more labour demanding however it enabled significantly (P < 0.05) more efficient collection of slowly moving or sedentary animals.
|
guest ::
