Tag Archives: Ward


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


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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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


Ward, B.A., M. Schartau, A. Oschlies, A.P. Martin, M.J. Follows and T.R. Anderson, TR (2013), When is a biogeochemical model too complex? Objective model reduction and selection for North Atlantic time-series sites Progress in Oceanography, vol. 116, pp. 49, doi:10.1016/j.pocean.2013.06.002


Ward, B.A., S. Dutkiewicz, C.M. Moore and M.J. Follows (2013), Iron, phosphorus, and nitrogen supply ratios define the biogeography of nitrogen fixation Limnology and Oceanography, vol. 58, pp. 2059, doi: 10.4319/lo.2013.58.6.2059



Barton, A.D., Z.V. Finkel, B.A. Ward, D.G. Johns and M.J. Follows (2013), The roles of cell size and trophic strategy in North Atlantic diatom and dinoflagellate communities. Limnology and Oceanography, 58(1), 2013, 254-266, doi: 10.4319/lo.2013.58.1.0254


Ward, B.A., S. Dutkiewicz, O. Jahn, and M.J. Follows (2012), A size structured food-web model for the global ocean: Linking physiology, ecology and biogeography, Limnology and Oceanography, 57, 1877-1891, doi: 10.4319/lo.2012.57.6.1877


Dutkiewicz, S., B. A. Ward, F. Monteiro, and M. J. Follows (2012), Interconnection of nitrogen fixers and iron in the Pacific Ocean: Theory and numerical simulations, Global Biogeochem. Cycles, 26, GB1012, doi: 10.1029/2011GB004039


Ecology of nitrogen fixers in the Pacific Ocean

Nitrogen is an essential component of all cells. It is used to make the amino acid building blocks of proteins, and is also required in the nucleic acids of DNA and RNA. Although nitrogen extremely abundant in the open ocean, it is mostly found in dissolved N2 molecules that cannot be used by most phytoplankton, who require nitrogen in its reduced, or “fixed” forms, such as nitrate or ammonium.

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Biophysical Aspects of Resource Acquisition and Competition in Algal Mixotrophs

Mixotrophic organisms combine autotrophic and heterotrophic nutrition and are abundant in both freshwater and marine environments. Recent observations indicate that mixotrophs constitute a large fraction of the biomass, bacterivory, and primary production in oligotrophic environments. While mixotrophy allows greater flexibility in terms of resource acquisition, any advantage must be traded off against an associated increase in metabolic costs, which appear to make mixotrophs uncompetitive relative to obligate autotrophs and heterotrophs.

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