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

Marine Ecology Progress Series

Kevin Wyman¹  Joon-Baek Lee¹  Pedro Cerme#xf1o¹  Paul G. Falkowski¹  Oscar Schofield¹ 

关键词: Ecological succession;    Marine phytoplankton;    Competition;    Nutrient perturbation;    Domain shift;    Ocean turbulence;    Climate change;   

DOI  :  10.3354/meps09088

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

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.

【 授权许可】

Unknown