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This thesis focuses on ecological processes among plankton organisms. It especially questions the influence of food quality on growth and survival of freshwater plankton. I focused on the influence of various ratios of nitrogen and phosphorus in available food. I am also interested in finding out the food requirements of chosen consumer Daphnia longispina. Within this broad topic, I specify a question, whether various quality and quantity of food influences the life history parameters of the species Daphnia longispina and whether the absence of common species of Cladoceran Daphnia longispina in Plešné Lake is caused by unsuitable quality of food. I have bred Daphnia longispina in laboratory conditions for two years. I fed it by algae Monoraphidium dybowskii isolated from Plešné Lake and grown in two media P-limited (C:P 1174), P-unlimited (C:P 290) and three concentration (1,2, 4 mg C/L). Cladocerans fed by food from medium that had a C:N:P ratio approximately the same as can be found in Plešné Lake (C:P 1174) lived for a singificantly shorter period of time and during the experiment they did not reproduce even in the case with the largest amount of food (4 mg C/L). This is a possible reason why Daphnia longispina did not return to Plešné Lake after the period of strong acidification, climax of...

The main aim of this dissertation was maping landscape around the vilage Kobylí. Before 170 year's ago was near of vilage Kobylí huge prehistoric lake. I defined during the maping important segment's, which make ecological network. In some place was create new segment's, like biocenter and biocoridor. For two biocenter's was made budget for realization and maintenance. The result is several map's about maping landscape include information about prehistorical lake. Head subject of this dissertation is issues ecological network and landscape planing. In addition, could be use this work for future territorial plan.

Thesis contains draft of loghouse. Project documentation is made for realization of loghouse recreational object type, which is placet Nera Hamerske lake. The draft is designed to follow valid regulations and related standards. For the respektive separate standing building, designed in the thesis, is chosen a suitable piece of land which the building is equipped according to standrads ČSN 73 4301- The distances between buildings. The loghouse is installed into the grand (for wooden building) by unconventional way of establishment underground od reinforced concrete bored piles, because its located near water area. Disposition of this work is dealt in accordance with valid hygienic regulations and standards following requests of future user of recreational object. At designed building is solving critical deatils resulting from the structural design and actual characteristics of wood. Emphasis is placed on details, which ensure right function of wood building as for example installation of the window in loghouse contruction or insulation of plinth.

Food, growth, sex ratio and depth distribution of perch (Perca fluviatilis L.) were studied in Milada Lake, Most Lake and Barbora Lake. These lakes were artificialy created after a coal mining. Sex ratio and depth distribution were also compared with data gathered from Vír Reservoir and Římov Reservoir. Fish designed for the research were captured by gillnets. Age analysis was carried out by otolite scanning. Food, growth and depth distribution were analysed with consideration of size and sex of the fish.

The thesis assesses forms of phosphorus, aluminium, and iron in soils of catchments of acidified mountain lakes. The aim of the study was to determinate changes in soil chemistry in catchments of Bohemian Forest lakes between years 2000 and 2010. The next aim was to compare fractionation according to Psenner and Pucsko (1988) with standard pedological extractions.

The thesis assesses forms of phosphorus, aluminium, and iron in soils of catchments of acidified mountain lakes. The aim of the study was to determinate changes in soil chemistry in catchments of Bohemian Forest lakes between years 2000 and 2010. The next aim was to compare fractionation according to Psenner and Pucsko (1988) with standard pedological extractions.

Structural changes in macrozoobenthic communities and changes in chemistry in longitudinal profiles of two acidified streams in the Bohemian Forest (Czech Republic) were investigated in 2007. The progress in chemical recovery was evident in both streams, whereas zoobenthos recovery was obvious only in less acidified stream.

This Ph.D. thesis presents new facts about a paleoenvironmental development of the northern part of the Bohemian Forest (area of Černé Lake and Čertovo Lake) in the Late Pleistocene and Early Holocene. The main goals of the research are: characterize the glacier landforms in the Bohemian Forest and define the variance of these landforms; determine factors influencing formation and development of the glaciation in the study area; describe environmental settings and its changes during deglaciation and in Early Holocene by using environmental proxies. This research proceeds from original data obtained by geomorphological mapping, morphometric analysis and proxy data analyses originated from a sediment sequence in a peat bog in the Černé Lake vicinity. The common attributes of the Bohemian Forest cirques and cirque variability was determined using morphometric and morphologic characteristics of the cirques on the Bavarian and Czech side of the mountain range. These characteristics were compared with other cirques of the Bohemian Massif and other chosen mountain ranges of the world. The cirque overdeepening was defined on the basis of headwall shapes and it emerged that overdeepening of the cirques in the Bavarian Forest and in the High Sudetes reflects a different extent of the Pleistocene glaciation....

Natural processes that cause differences in rates of decomposition and mineralisation of organic plants matter in soils of Sumava mountains' glacial lakes were studied using plant litter dominant in understorey of spruce forest in watershed of two lakes, Plesne and Certovo. The aim of this study is to determine the effect plant liter chemistry on decomposition and mineralisation rate. We hypothetize that chemistry of liter of understorey vegetation significantly affect N mineralisation / immobilisation in siols. During four month laboratory experiment were studied the effect of litter quality characteristics on C mineralization rates and N release. Spruce needles (Picea abies) and leaves of four dominant species (Avenella flexuosa, Calamagrostis villosa, Vaccinium myrthillus and Athyrium alpestre) of understorey vegetation were collected in autumn 2006. Litter was incubated at 0 and 10 °C. CO2 release was regularly measured each 14 days. Amounts of phenolics, available phosphorus, total and extractable C and N, release of NH4+ and NO3- were measured at the beginning, after one and four months of incubation.