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You cannot step into the same fishpond twice - an evolution of fishpond ecosystems to hypertrophy
Vrba, Jaroslav ; Benedová, Z. ; Jezberová, Jitka ; Matoušů, Anna ; Musil, M. ; Nedoma, Jiří ; Pechar, L. ; Potužák, J. ; Řeháková, Klára ; Šimek, Karel ; Šorf, M. ; Zemanová, J.
Shallow manmade fishponds in south Bohemia were used for fish production for centuries, however, their ecosystems have changed dramatically due to excessive nutrient loading and fish stocking. Preliminary results of ten sampled fishponds suggested their hypertrophic status at present, while their plankton structure and dynamics reflected the actual size/age class of fish stock consisting predominantly of common carp. Planktivorous fish (both young carp and whitefish) remarkably reduced abundance, size, and species diversity of crustacean zooplankton, in particular large daphnids, whereas larger carp itself did not cause such a strong top-down effect. All other plankton components, i.e. phytoplankton, bacteria, protists, and rotifers showed rather high abundance and diversity, and suggested a reasonable impact of various microbial processes and interactions in the recent hypertrophic ecosystems.
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Aktivita a výskyt metanotrofních bakterií v povrchových vodách řeky Labe
MATOUŠŮ, Anna
During this PhD. thesis, the importance of methane-oxidizing bacteria (methanotrophs) and their ecological demands were studied on the longitudinal transect along an important European river - the River Elbe. However, it was necessary to adjust methodologies for precise measurements of methane oxidation in such a variable aquatic environment. Based on laboratory experiments and field measurements, several key methodological recommendations for future planning of methane oxidation rate estimations in an unknown environment have been identified or specified. In line with the variability of the river habitats, considerable heterogeneity was also found in the obtained data on methane concentration and methanotrophical activity. Probably, some of the most important information gathered during many field sampling campaigns is that sites with the highest methane concentration usually showed a very low activity of methanotrophic bacteria (resulting in higher methane emissions). These sites are predominantly human modified sections of the river, such as locks, weirs, harbors and canals. On the contrary, the free-flowing parts of the river, modified only by groynes, showed low level of methane concentration. And so groynes could represent a more effective solution and "natural-close" habitats of navigability of rivers.
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Restoration of species-rich meadow ecosystems on mine spoil dumps.
MATOUŠŮ, Anna
Main object of this study was to accelerate and to direct succession in the course of a 5-year field experiment on a mine spoil dump. The effects of (1) transplanting whole meadow turfs, (2) spreading meadow soil with turfs, (3) spreading diaspore-rich mown vegetation and (4) different types of management, as possible restoration techniques are discussed in the thesis
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