Photoacclimation and nutrient-based model of light-saturated photosynthesis for quantifying oceanic primary production
Behrenfeld, M.J.; Marañón, E.; Siegel, D.A.; Hooker, S.B. (2002). Photoacclimation and nutrient-based model of light-saturated photosynthesis for quantifying oceanic primary production. Mar. Ecol. Prog. Ser. 228: 103-117
In: Marine Ecology Progress Series. Inter-Research: Oldendorf/Luhe. ISSN 0171-8630; e-ISSN 1616-1599, more
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| Authors | | Top |
- Behrenfeld, M.J.
- Marañón, E.
- Siegel, D.A.
- Hooker, S.B.
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| Abstract |
Availability of remotely sensed phytoplankton biomass fields has greatly advanced primary production modeling efforts. However, conversion of near-surface chlorophyll concentrations to carbon fixation rates has been hindered by uncertainties in modeling light-saturated photosynthesis (Pbmax). Here, we introduce a physiologically-based model for Pbmax that focuses on the effects of photoacclimation and nutrient limitation on relative changes in cellular chlorophyll and CO2 fixation capacities. This ‘PhotoAcc’ model describes P bmax as a function of light level at the bottom of the mixed layer or at the depth of interest below the mixed layer. Nutrient status is assessed from the relationship between mixed layer and nutricline depths. Temperature is assumed to have no direct influence on P bmax above 5°C. The PhotoAcc model was parameterized using photosynthesis-irradiance observations made from extended transects across the Atlantic Ocean. Model performance was validated independently using time-series observations from the Sargasso Sea. The PhotoAcc model accounted for 70 to 80% of the variance in light-saturated photosynthesis. Previously described temperature-dependent models did not account for a significant fraction of the variance in P bmax for our test data sets. |
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