Category Archives: Top-Down Control

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Darwin goes to Ocean Sciences 2014

Leaving the cold of a New England February behind, the Darwin team will be in full attendance at this year’s Ocean Sciences conference taking place February 23-28 in Honolulu, Hawaii.

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Size Structure: exploring nutrient versus grazing control

Idealized equilibrium models have attributed the observed size structure of marine communities to the interactions between nutrient and grazing control. In a new paper in the Journal of Plankton Research Ben Ward and co-authors Stephanie Dutkiewicz and Mick Follows examine this theory in a more realistic context using a size-structured global ocean food-web model, together with a much simplified version of the same model for which equilibrium solutions are readily obtained.

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Publication

Ward, B.A., S. Dutkiewicz, and M.J. Follows (2014) Modelling spatial and temporal patterns in size-structured marine plankton communities: top-down and bottom-up controls, Journal of Plankton Research, 0, 1-17, doi:10.1093/plankt/fbt097

Publication

Ward, B.A., S. Dutkiewicz, and M.J. Follows (2013), Top-down and bottom-up controls in a global size-structured plankton food-web model, Journal of Plankton Research , 0, 1-17, doi: 10.1093/plankt/fbt097

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The dynamics of dining in an all-you-can-eat-phytoplankton buffet

Predators’ switching towards the most abundant prey is a mechanism that stabilizes population dynamics and helps overcome competitive exclusion of species in food webs. However, current formulations of active prey-switching in marine ecosystem models display non-maximal feeding; the total ingestion of prey by predators decays exponentially with the number of prey species even though the total prey biomass stays constant.

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Publication:

Vallina, S. M. , B. A. Ward, S. Dutkiewicz, and M. J. Follows (2013), Maximal feeding with active prey-switching: a kill-the-winner functional response and its effect on global diversity and biogeography, Progress in Oceanography, 120, 93–109, doi: 10.1016/j.pocean.2013.08.001

Publication

Prowe, A. E. F., M. Pahlow, S. Dutkiewicz, M. Follows, and A. Oschlies (2012), Top-down control of marine phytoplankton diversity in a global ecosystem model, Progr. Oceanogr., doi:10.1016/j.pocean.2011.11.016