Composition and dominance of edible and inedible phyto-plankton predict responses of Baltic Sea summer communities to elevated temperature and CO2 ...

• Main Authors: Paul, Carolin, Sommer, Ulrich, Matthiessen, Birte
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2021
• Subjects: Baltic Sea; Climate change; CO2; grazing; Phytoplankton; warming; Biological Impacts of Ocean Acidification BIOACID; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.939015; https://doi.pangaea.de/10.1594/PANGAEA.939015

Previous studies with Baltic Sea phytoplankton combining elevated seawater temperature with CO2 revealed the importance of size trait-based analyses, in particular dividing the plankton in-to edible (> 5 and < 100 µm) and inedible (< 5 and > 100 µm) size classes for mesozoopankton grazers. While the edible phytoplankton responded predominantly negative to warming and the inedible group stayed unaffected or increased, independent from edibility most phyto-plankton groups gained from CO2. Because the ratio between edible and inedible taxa changes profoundly over seasons, we investigated, if community responses can be predicted according to the prevailing composition of edible and inedible groups. We experimentally explored the combined effects of elevated temperatures and CO2 concentrations on a late-summer Baltic Sea community. Total phytoplankton significantly increased in response to elevated CO2 in particu-lar in combination with temperature, driven by a significant gain of the inedible < 5 ...