Samuel Barton1, James Jenkins1, Angus Buckling1, C-Elisa Schaum2, Nicholas Smirnoff3, John A Raven4,5,6, Gabriel Yvon-Durocher1. 1. Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK. 2. Institute for Hydrobiology and Fisheries, Section Oceanography, Hamburg University, 22767, Hamburg, Germany. 3. Biosciences, College of Life and Environmental Sciences, Geoffrey Pope Building University of Exeter, Exeter, EX4 4QD, UK. 4. Division of Plant Science, University of Dundee at the James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK. 5. Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia. 6. School of Biology, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
Abstract
The efficiency of carbon sequestration by the biological pump could decline in the coming decades because respiration tends to increase more with temperature than photosynthesis. Despite these differences in the short-term temperature sensitivities of photosynthesis and respiration, it remains unknown whether the long-term impacts of global warming on metabolic rates of phytoplankton can be modulated by evolutionary adaptation. We found that respiration was consistently more temperature dependent than photosynthesis across 18 diverse marine phytoplankton, resulting in universal declines in the rate of carbon fixation with short-term increases in temperature. Long-term experimental evolution under high temperature reversed the short-term stimulation of metabolic rates, resulting in increased rates of carbon fixation. Our findings suggest that thermal adaptation may therefore have an ameliorating impact on the efficiency of phytoplankton as primary mediators of the biological carbon pump.
The efficiency of carbon sequestration by the biological pump could decline in the coming decades because respiration tends to increase more with temperature than photosynthen class="Chemical">sis. Despite these differences in the short-term temperature sensitivities of photosynthesis and respiration, it remains unknown whether the long-term impacts of global warming on metabolic rates of phytoplankton can be modulated by evolutionary adaptation. We found that respiration was consistently more temperature dependent than photosynthesis across 18 diverse marine phytoplankton, resulting in universal declines in the rate of carbon fixation with short-term increases in temperature. Long-term experimental evolution under high temperature reversed the short-term stimulation of metabolic rates, resulting in increased rates of carbon fixation. Our findings suggest that thermal adaptation may therefore have an ameliorating impact on the efficiency of phytoplankton as primary mediators of the biological carbon pump.
Authors: Nathan G Walworth; Jana Hinners; Phoebe A Argyle; Suzana G Leles; Martina A Doblin; Sinéad Collins; Naomi M Levine Journal: Proc Biol Sci Date: 2021-06-16 Impact factor: 5.349