Dynamic model of phytoplankton growth and acclimation:responses of the balanced growth rate and the chlorophyll a:carbon ratio to light, nutrient-limitation and temperature

Abstract

Acclimation of the photosynthetic apparatus to changes of irradiance, temperature and nutrient availability, involving regulation of the chlorophyll a:carbon ratio (g), is a universal feature of all phytoplankton studied to date. We derive a dynamic regulatory model that predicts the dependencies of 8 and growth rate ( U ) on irradiance, daylength, temperature and nutrient availdbilitv. Thc model requires specification of 4 parameters to describe the light-dependencies of 8 and g under nutr~ent-saturating conditions at constant temperature. These are the maximum value of 8 (B,,), the in~tial slope of the chl a-specific photosynthesis-light response curve (aCh'), the mdximum carbon-spcclfic photosynt h e s~s rate (P:;) and the cost of biosynthesis (C). The influences of temperature and nutnent availability are accommodated through their effects on P: . The temperature dependence is described by the slope of an Arrhenius plot and the nutrient dependence IS described through the half saturation constant (K,) of the Monod equation. Fidelity of the model results to empirical studies suggests that microalgal cells adjust 0 in response to an imbalance between the rate of light absorption and the energy demands for photosynthesis and biosynthesis.

Net primary productivity estimates and environmental variables in the Arctic Ocean: An assessment of coupled physical-biogeochemical models

“…However, COBALT enhances the resolution of planktonic food web dynamics to better understand the climate impacts on the flow of energy from phytoplankton to fish [Stock et al, 2014b]. The model includes three phytoplankton groups (small, large, and diazotrophs) and uses the variable chlorophyll:C formulation of Geider et al, [1997] to estimate NPP. Results contributed to this study were conducted with the Modular Ocean Model (MOM) version 4p1 [Griffies, 2012] with sea ice dynamics as described in Winton coupled atmosphere dynamics [Griffies et al, 2009].…”

“…TOPAZ2 includes 30 tracers to describe the cycles of C, N, P, Si, Fe, O 2 , alkalinity, and lithogenic material as well as surface sediment calcite dynamics [Dunne et al, 2012a]. TOPAZ2 considers three explicit phytoplankton groups (small, large, and diazotrophs) that utilize a modified growth physiology after Geider et al [1997] with Eppley [1972] temperature functionality and iron colimitation with luxury uptake after Sunda and Huntsman [1997]. CO 2 :NO 3 :O 2 stoichiometry is 106:16:150 after Anderson [1995].…”

Modelling aggregate formation and sedimentation of organic and mineral particles

“…ρ CHL denotes the carbon-specific chlorophyll growth rate as in Geider et al (1997). θ and θ m are the chl:carbon and maximum chl:carbon ratios, respectively.…”

“…where λ NO3 and λ NH4 denote the light-and nutrient-limited (Geider et al, 1997) nitrogen uptake rates of phytoplankton. AD represents the vertical advection and diffusion term, ϱ PHY and ϱ DET represent the remineralization rates of phytoplankton and detritus, and ϱ NN is the NH 4 to NO 3 regeneration rate.…”

Numerical modelling of spatio-temporal variability of growth of Mytilus edulis (L.) and influence of its cultivation on ecosystem functioning

“…Since CChl changes due to the effects of photoacclimation, it is modelled according to the formulations given in Geider et al (1997) and Geider et al (1998).…”