Warming and Acidification Effects on Planktonic Heterotrophic Pico- and Nanoflagellates in a Mesocosm Experiment.
We studied the response of the heterotrophic flagellate (HF) community to the combined impact of warming and ocean acidification in a mesocosm experiment with a plankton community from the western Baltic Sea. We performed a quantitative analysis of the response at the level of total biomass and size classes and a semi-quantitative one at the level of individual taxa. Total biomass of HF was significantly lower under higher temperatures while there was no significant effect of CO2. The mean biomass of the picoflagellates did not respond to temperature while the three nanoflagellate size classes (class limits 3, 5, 8, 15μm) responded negatively to warming while not responding to CO2. The taxon-level results indicate that heterotrophic flagellates do not form a homogenous trophic guild, as often assumed in pelagic food web studies. Instead, the heterotrophic flagellates formed a "food web within the food web". There was a pronounced succession of flagellates leading from a dominance of bacterivores and colloidal matter feeders before the phytoplankton bloom to omnivorous feeders preying upon phytoplankton and heterotrophic flagellates during and after the bloom. This complex intraguild predation patterns probably dampened the response to experimental treatments.
['Moustaka-Gouni|Maria|M|', 'Kormas|Konstantinos A|KA|', 'Scotti|Marco|M|', 'Vardaka|Elisabeth|E|', 'Sommer|Ulrich|U|']
D000818:Animals D018533:Biomass D057231:Climate Change D017753:Ecosystem D020387:Food Chain D005858:Germany D006358:Hot Temperature D006863:Hydrogen-Ion Concentration D010839:Phytoplankton D012623:Seawater D015048:Zooplankton
acidification heterotrophic flagellates Global Change microbial food-web plankton.