Contrasting effects of rising CO₂ on primary production and ecological stoichiometry at different nutrient levels

• Published in: Ecology letters Vol. 17; no. 8; pp. 951 - 960
• Main Authors: Verspagen, Jolanda M. H, Van de Waal, Dedmer B, Finke, Jan F, Visser, Petra M, Huisman, Jef, Grover, James
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Science 01.08.2014; Blackwell Publishing Ltd; Blackwell
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Biomass; carbon; Carbon dioxide; Carbon Dioxide - metabolism; Climatology. Bioclimatology. Climate change; Cyanobacteria; Earth, ocean, space; Ecology; Ecosystem; elemental stoichiometry; eutrophication; Exact sciences and technology; External geophysics; Fresh water ecosystems; freshwater; Fundamental and applied biological sciences. Psychology; General aspects; global change; Greenhouse gases; harmful algal blooms; Herbivores; Inorganic carbon; lakes; mathematical models; Meteorology; Microcystis - physiology; Microcystis aeruginosa; Models, Biological; Nutrient concentrations; nutrient content; nutrient limitation; Nutrient loading; Nutritional Physiological Phenomena; Nutritive value; ocean acidification; Phytoplankton; pollution load; Population Density; Population Dynamics; prediction; Primary production; primary productivity; stoichiometry; Synecology; ocean acidification; Stoichiometry; Microcystis aeruginosa; Primary productivity; Algae; Carbon dioxide; Acidification; elemental stoichiometry; Eutrophication; Dynamical climatology; Freshwater environment; Climate change; Limiting factor; Cyanobacteria; Bloom; Global change; Planetary scale; Lakes; nutrient limitation; Bacteria; Nutrient; Ocean; harmful algal blooms; Harmful alga; eutrophication; global change; lakes
• ISSN: 1461-023X; 1461-0248; 1461-0248
• DOI: 10.1111/ele.12298

Although rising CO₂ concentrations are thought to promote the growth and alter the carbon : nutrient stoichiometry of primary producers, several studies have reported conflicting results. To reconcile these contrasting results, we tested the following hypotheses: rising CO₂ levels (1) will increase phytoplankton biomass more at high nutrient loads than at low nutrient loads, but (2) will increase their carbon : nutrient stoichiometry more at low than at high nutrient loads. We formulated a mathematical model to predict dynamic changes in phytoplankton population density, elemental stoichiometry and inorganic carbon chemistry in response to rising CO₂. The model was tested in chemostat experiments with the freshwater cyanobacterium Microcystis aeruginosa. The model predictions and experimental results confirmed the hypotheses. Our findings provide a novel theoretical framework to understand and predict effects of rising CO₂ concentrations on primary producers and their nutritional quality as food for herbivores under different nutrient conditions.