Errata and re-visitation of What is the limit for photoautotrophic plankton growth rates? (Flynn and Raven, 2017)

An error in our original work prompts a revisitation of factors constraining photoautotrophic plankton growth rates (mu(max)). Ribulose-1,5-bisphosphate Carboxylase-Oxygenase does not itself provide that constraint, but we identify other factors that result in our previously suggested value of similar to 2 doublings per day still likely being representative of the maximum for most photoautotrophs. mu(max) likely evolves to balance the advantage of possessing a high competitive value while minimizing the stresses incurred when the organism is incapable of routinely achieving a higher mu(max) due to various limiting factors. Organisms with extreme high mu(max) are thus expected to grow under conditions that provide the necessary environment (stable pH, non-limiting nutrients and light) for sufficient time that the evolution of higher mu(max) becomes advantageous. Conditions in nature allowing the evolution of higher mu(max) include the exploitation of an exceptional opportunity and then entering stasis (e.g. desert microalgae), or a situation where high grazing pressures match high phytoplankton growth, thus maintaining non-limiting nutrient and light conditions. The latter, however, conflicts with the paradox of enrichment, as only under resource limitation would the necessary stability be attained in the predator-prey dynamic. Ultimately, ecology, not biophysics, constrains phototroph mu(max).

Automated summary

An error in our original work led us to reevaluate the factors constraining photoautotrophic plankton growth rates (mu(max)). Ribulose-1,5-bisphosphate Carboxylase-Oxygenase does not provide this constraint, but we identified other factors that suggest our previously suggested value of approximately 2 doublings per day is still likely representative of the maximum for most photoautotrophs. mu(max) likely evolves a balance between competitive advantage and minimizing stress caused by various limiting factors. Organisms with extremely high mu(max) are expected to grow under specific conditions that provide a stable environment with non-limiting nutrients and light for sufficient time to evolve higher mu(max). Conditions allowing for higher mu(max) include exploiting exceptional opportunities and entering stasis, or situations where high grazing pressures match high phytoplankton growth, maintaining non-limiting nutrient and light conditions. However, the latter conflicts with the paradox of enrichment, as predator-prey dynamics only achieve necessary stability under resource limitation. Ultimately, phototroph mu(max) is constrained by ecology, not biophysics.