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Zooplankton response to a change of water chemistry and amount of food during the recovery of lakes from acidification
Bartošíková, Martina ; Stuchlík, Evžen (advisor) ; Šorf, Michal (referee)
Anthropogenic acidification has affected assemblages in thousands of lakes in North America and Europe. It turned out that, during the acidification, the number of zooplankton changed and also the species composition of their assemblages, at some sites there was also the total disappearance. The main reason was a decrease of pH, wash out toxic aluminium and a change of trophic status. The rate and extent of biological recovery after restoring the pH in acidified lakes varies considerably across regions. Recovery of aquatic communities is significantly lagging behind the recovery in chemistry. Some zooplankton species are nonetheless able to quickly colonize recuperating ecosystems and in many acidified lakes again started to appear native species that have disappeared during acidification. The return of indigenous species, however, can be blocked acid-tolerant occurrence of species after species extinct occupied empty niches. Zooplankton can be affected by water chemistry directly, but also indirectly by the quality and quantity of food. An important factor is the possible spread of colonizing species. However, the relative roles of these factors in regulating recovery may be difficult to determine. Key words: zooplankton, acidification, water chemistry, aluminium toxicity, phytoplankton
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