Role of zooplankton dynamics for Southern Ocean phytoplankton biomass and global biogeochemical cycles ...

• Main Authors: Le Quéré, Corinne, Buitenhuis, Erik T., Moriarty, Róisín, Alvain, Séverine, Aumont, Olivier, Bopp, Laurent, Chollet, Sophie, Enright, Clare, Franklin, Daniel J., Geider, Richard J., Harrison, Sandy P., Hirst, Andrew G., Larsen, Stuart, Legendre, Louis, Platt, Trevor, Prentice, I. Colin, Rivkin, Richard B., Sailley, Sévrine, Sathyendranath, Shubha, Stephens, Nick, Vogt, Meike, Vallina, Sergio M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2016
• Subjects: Southern Ocean
• Online Access: https://dx.doi.org/10.3929/ethz-b-000119006; http://hdl.handle.net/20.500.11850/119006

Global ocean biogeochemistry models currently employed in climate change projections use highly simplified representations of pelagic food webs. These food webs do not necessarily include critical pathways by which ecosystems interact with ocean biogeochemistry and climate. Here we present a global biogeochemical model which incorporates ecosystem dynamics based on the representation of ten plankton functional types (PFTs): six types of phytoplankton, three types of zooplankton, and heterotrophic procaryotes. We improved the representation of zooplankton dynamics in our model through (a) the explicit inclusion of large, slow-growing macrozooplankton (e.g. krill), and (b) the introduction of trophic cascades among the three zooplankton types. We use the model to quantitatively assess the relative roles of iron vs. grazing in determining phytoplankton biomass in the Southern Ocean high-nutrient low-chlorophyll (HNLC) region during summer. When model simulations do not include macrozooplankton grazing ... : Biogeosciences, 13 (14) ...