The hypothesis to be tested is that blue-green algae (Cyanobacteria) will in general be found to be more efficient in using CO2 than will most non blue-green algae, thus leading to blue-green dominance when pH is high and CO2 is low. The hypothesis will be tested during a whole growing season in two lakes using + and - enrichments with CO2 by changing pH. The experiments will be evaluated by measuring CO2 uptake with 14C microautoradiography.
