MEPS 429:19-28 (2011)  -  DOI: https://doi.org/10.3354/meps09088

Competitive dynamics in two species of marine phytoplankton under non-equilibrium conditions

Pedro Cermeño1,4,*, Joon-Baek Lee1,2, Kevin Wyman1, Oscar Schofield1, Paul G. Falkowski1,3

1Environmental Biophysics and Molecular Ecology Program, Institute of Marine and Coastal Sciences, Rutgers University,
71 Dudley Road, New Brunswick, New Jersey 08901, USA
2Department of Earth and Marine Sciences, College of Ocean Sciences, and Marine and Environmental Research Institute, Jeju National University, Jeju 690-756, ROK
3Department of Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, New Jersey, 08854, USA
4Present address: Departamento de Ecología y Biología Animal, Universidad de Vigo, 36310 Vigo, Spain

ABSTRACT:  Although mathematical models suggest that competition between primary producers in response to dynamical changes in the availability of a limiting nutrient is non-linear, experimental data supporting this basic hypothesis are sparse. Using continuous culture systems with nitrate as a single limiting nutrient, we present results of competition experiments between 2 species of marine phytoplankton, a diatom Thalassiosira pseudonana and a coccolithophore Coccolithus braarudii. These 2 organisms of similar size represent biogeochemically and ecologically distinct functional groups. Consistent with classical resource competition theory, under steady-state nitrate limitation (i.e. continuous flow chemostats), the diatom was outcompeted by the coccolithophore. However, when pulses of nitrate were provided to the chemostats (i.e. non-equilibrium, dynamical conditions) the diatom outcompeted the coccolithophore. The rate of exclusion was a linear function of the frequency of nitrate pulses. These results experimentally demonstrate that dynamical nutrient supply allows co-existence of 2 primary producers competing for a single limiting nutrient and may help us to understand phytoplankton succession in the ocean.


KEY WORDS: Ecological succession · Marine phytoplankton · Competition · Nutrient perturbation · Domain shift · Ocean turbulence · Climate change


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Cite this article as: Cermeño P, Lee JB, Wyman K, Schofield O, Falkowski PG (2011) Competitive dynamics in two species of marine phytoplankton under non-equilibrium conditions. Mar Ecol Prog Ser 429:19-28. https://doi.org/10.3354/meps09088

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