English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Scaling laws are central to relate ecological and physiological traits in unicellular autotrophs. Classical uniform scaling applied to phytoplankton maximum growth rate (μ max ), however, meets several theoretical and empirical limitations. As an alternative model, I propose a non-uniform size dependency of μ max  by considering how the geometry of unicells determines photosynthetic capacity. The model starts from physical laws of absorption and diffusion and uses known biochemical or biophysical coefficients. Calculated intracellular light and CO 2  levels decline from the membrane to the cell centre, which may depress photosynthesis even under optimal growth conditions. Combination of the depletion model with a mechanistically motivated scaling rule for respiration generates a uni-modal size function for μ max . The function greatly improves predictions of classical allometries, in particular, for small cells and across taxonomic groups. Uni-modality in μ max  has various implications for phytoplankton eco-physiology and morphology, correctly describing the absence of very small diatoms or giant green algae. For larger size classes, an increased benefit of non-spherical forms or of elevated pCO 2  is calculated, whereas the advantage of carbon concentrating mechanisms turns out to be maximal for intermediate sizes. The model also points to a high degree of co-adaptation in different uptake systems.

Non-uniform scaling in phytoplankton growth rate due to intracellular light and CO 2 decline