A microalgal growth model

Abstract

Recent experimental evidence has made it clear that effects of irradiance and nutrient limitation on light absorption and photosynthetic quantum yields of microalgae and the relationship between cellular N : C ratios and nutrient-limited growth rates are inconsistent with the assumptions and predictions of current models of algal growth. A new algal growth model was therefore developed to overcome these inconsistencies. The new model predicts a hyperbolic relationship between nutrient-saturated growth rates and irradiance and a linear relationship between growth rate and both respiration rate and Chl a : C ratios. The correlation between growth rate and Chl a : C is positive under nutrient-limited conditions and negative under nutrient-saturated (light-limited) conditions. The requirement that N : C ratios be linearly related to relative growth rates leads to the conclusion that the product of the Chl a-specific absorption coefficient and the quantum yield coefficient be hyperbolically related to nutrient-limited growth rates, a result consistent with experimental observations. The equations relating respiration rate and compositional ratios to absolute and relative growth rates appear to be insensitive to photoperiod.

New cell-based model of photosynthesis and photo-acclimation: accumulation and mobilisation of energy reserves in phytoplankton

“…Geider et al (1996Geider et al ( , 1998 and Flynn et al (1997) were the first to employ dynamic acclimation models to phytoplankton growth and physiological acclimation. Unlike previous models, which were based on balanced growth under prescribed but invariant environmental conditions (Bannister 1979, Shuter 1979, Kiefer & Mitchel 1983, Laws & Chalup 1990, the dynamic models were developed for application to variable Fig. 8.…”

Process-based primary production modeling in Chesapeake Bay

“…Respiration: Laws & Chalup (1990) reported values of 0.03 d -1 for maintenance respiration and 0.28 for active respiration. Other investigators have found that from 15 to 35% of carbon fixed is lost to metabolism (Groeger & Kimmel 1989, Kiddon et al 1995.…”

Chain model of phytoplankton P, N and light colimitation

“…The cellquota approach has been used to construct phytoplankton growth models describing the interactions of light and nutrient limitation (e.g. Laws & Chalup 1990, Geider et al 1998), but few attempts have been made to include effects of different nutrient elements in a mechanistic theory (Flynn 2001, Flynn 2008. Colimitation by several nutrients has been classified on a theoretical basis by Arrigo (2005), who distinguished direct effects of nutrient concentration (multi-nutrient colimitation), organismlevel effects (biochemical colimitation) and populationlevel effects (community colimitation).…”