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Gradoville, M. R., Oregon State University, Corvallis, USA, rgradoville@coas.oregonstate.edu
White, A. E., Oregon State University, Corvallis, USA, awhite@coas.oregonstate.edu
Zirbel, M. J., Oregon State University, Corvallis, USA, mjzirbel@coas.oregonstate.edu
Böttjer, D. ., University of Hawaii, Honolulu, USA, dbottjer@hawaii.edu
Church, M. J., University of Hawaii, Honolulu, USA, mjchurch@hawaii.edu
Letelier, R. M., Oregon State University, Corvallis, USA, letelier@coas.oregonstate.edu


Growth and di-nitrogen (N2) fixation rates of cultured strains of Trichodesmium and Crocosphaera appear to increase as a function of pCO2 concentration. Despite several research groups’ confirmation of the relationship between pCO2 and diazotrophic growth in the laboratory, field experiments conducted in the North Pacific Subtropical Gyre (NPSG) have found no significant relationship between pCO2 enrichments and rates of Trichodesmium N2 fixation. These disparate results may in part be explained by differences in the time scales of perturbation and adaptation employed in the laboratory and in field experiments. Under natural conditions, phytoplankton experience a range of temporal scales of change leading to episodic, diurnal, seasonal and long term trends in pCO2 variability. We will present results from experiments designed to test how time scales of pCO2 acclimation influence carbon and N2 fixation rates by laboratory isolates of Trichodesmium and Crocosphaera over a range of pCO2 conditions. These results will be discussed in the context of the observed scales of pCO2 variability in surface waters of the NPSG.

Poster presentation

Session #:046
Date: 2/23/2012
Time: 17:00 - 18:00
Location: Poster/Exhibit Hall

Presentation is given by student: Yes

PosterID: A0196