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Recent recovery of acidified lakes in the Bohemian Forest
Vrba, Jaroslav ; Fott, J. ; Kopáček, Jiří ; Kohout, L.
In some of the eight glacial lakes in the Bohemian Forest we have observed first signs of zooplankton recovery from acidity. The recovery has followed a drop in atmospheric sulphur and nitrogen deposition and consequent reversal in water chemistry of the lakes during the last decade. At present, stable populations of Ceriodaphnia quadrangula have returned to Lake Černé and Prášilské, and two circumneutral rotifers have recently occurred in the lakes with positive alkalinity: Laka, Großer and Kleiner Arbersee. Moreover, in the mesotrophic, strongly acidified Lake Plešné, we documented increase in both phytoplankton and planktonic rotifers during the 1990s. A statistical comparison of seasonal data showed a significant increase in pH, a significant drop in total reactive aluminium, a significant increase in chlorophyll a concentration as well as in summer abundance of planktonic rotifers.
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