Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK.
Institute for Hydrobiology and Fisheries, Section Oceanography, Hamburg University, 22767, Hamburg, Germany.
Ecol Lett. 2020 Apr;23(4):722-733. doi: 10.1111/ele.13469. Epub 2020 Feb 14.
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.
生物泵固碳的效率可能在未来几十年下降，因为呼吸作用对温度变化的敏感性往往比光合作用更强。尽管光合作用和呼吸作用在短期对温度的敏感性存在差异，但目前尚不清楚全球变暖对浮游植物代谢率的长期影响是否可以通过进化适应来调节。我们发现，在 18 种不同的海洋浮游植物中，呼吸作用的温度依赖性始终强于光合作用，导致随着短期温度升高，碳固定率普遍下降。在高温下进行长期实验进化会逆转代谢率的短期刺激，从而提高碳固定率。我们的研究结果表明，因此，热适应可能会对浮游植物作为生物碳泵主要介导者的效率产生有益的影响。
