Multiple environmental controls on phytoplankton growth strategies determine adaptive responses of the N : P ratio

• Published in: Ecology letters Vol. 17; no. 4; pp. 414 - 425
• Main Authors: Daines, Stuart J, Clark, James R, Lenton, Timothy M, Grover, James
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.04.2014; Blackwell
• Subjects: Adaptation, Physiological; Animal and plant ecology; Animal, plant and microbial ecology; biogeochemical cycles; Biogeochemistry; biogeography; Biological and medical sciences; ecophysiology; ecosystems; Environment; Fundamental and applied biological sciences. Psychology; General aspects; marine; microbial; Models, Biological; N/P; Nitrogen - chemistry; Nitrogen - metabolism; phosphorus; Phosphorus - chemistry; Phosphorus - metabolism; phytoplankton; Phytoplankton - growth & development; Phytoplankton - physiology; Phytotoxicity; Plankton; Proteins; Redfield ratios; Ribonucleic acid; RNA; RNA, Ribosomal - metabolism; Sea water ecosystems; Seawater - chemistry; stoichiometry; Synecology; traits; translation (genetics); Stoichiometry; traits; Growth; Adaptive response; Biogeography; Redfield ratios; Phosphorus; Biogeochemical cycle; Nitrogen; microbial; N/P; marine; Marine environment; Biogeochemistry; Phytoplankton; Strategy; Ratio; Microorganism; stoichiometry; biogeography; phytoplankton
• ISSN: 1461-023X; 1461-0248
• DOI: 10.1111/ele.12239

The controls on the ‘Redfield’ N : P stoichiometry of marine phytoplankton and hence the N : P ratio of the deep ocean remain incompletely understood. Here, we use a model for phytoplankton ecophysiology and growth, based on functional traits and resource‐allocation trade‐offs, to show how environmental filtering, biotic interactions, and element cycling in a global ecosystem model determine phytoplankton biogeography, growth strategies and macromolecular composition. Emergent growth strategies capture major observed patterns in marine biomes. Using a new synthesis of experimental RNA and protein measurements to constrain per‐ribosome translation rates, we determine a spatially variable lower limit on adaptive rRNA:protein allocation and hence on the relationship between the largest cellular P and N pools. Comparison with the lowest observed phytoplankton N : P ratios and N : P export fluxes in the Southern Ocean suggests that additional contributions from phospholipid and phosphorus storage compounds play a fundamental role in determining the marine biogeochemical cycling of these elements.