Large pools and fluxes of carbon, calcium and phosphorus in dense charophyte stands in ponds.

Bicarbonate and calcium set bounds on photosynthesis and degradation processes in calcareous freshwaters. Charophytic algae use bicarbonate in photosynthesis, and direct variable proportions to assimilate organic carbon and to precipitate calcium carbonate on their surfaces. To evaluate pools of organic carbon (C), carbonate carbon (C), and phosphorus (P) in dense charophyte vegetation, we studied apical and basal tissue and carbonate surface precipitates, as well as underlying sediments in ten calcareous ponds.