Cover illustration: The inset cover image shows a dense stand of the submerged isoetid, Lobelia dortmanna, with peduncles raising flowers towards the water surface. Lobelia dortmanna grows in low-alkaline lakes and is one out of several submerged plants that takes up CO2 for photosynthesis from the sediment (photograph by Ole Pedersen). See Winkel and Borum (pp. 1015-1023).
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