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Changes in nutrient availability imprinted in long-term diatom succession in lakes
Tichá, Anna ; Kuneš, Petr (advisor) ; Magyari, Enikő Katalin (referee) ; Catalan, Jordi (referee)
An examination of primary production in lakes shows regular trends during the Late Glacial and the Holocene periods: an increase ('eutrophication') and a decrease ('oligotrophication') usually connected with the input of terrestrial organic matter ('dystrophication'). Although nutrient availability usually influences production, other abiotic and biotic factors enter lakes' complex ontogeny, such as light availability, mixing regime, pH level, mechanical disturbance, predation or competition. Consequently, the past relationship between nutrient availability and primary production contains important information about the drivers of ecosystem functioning in the past. The reconstruction of past processes relies on the sensitive response of aquatic organisms to environmental changes. Their subfossil remains record the dynamic processes in the sediments and reveal both the local lacustrine history and more global events. Among other organisms, diatoms fulfil their function as a valuable proxy of past physical and chemical properties of water bodies. Whereas the record of planktonic diatom species dynamics represents the general ecosystem condition, variations in species-rich littoral periphytic diatoms add necessary insight into finer environmental fluctuations. The presented research combines...
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