Gao Kunshan, Campbell Douglas A
State Key Laboratory of Marine Environmental Science, Xiamen University, 361005 Xiamen, China.
Department of Biology, Mount Allison University, Sackville, NB E4L 1G7, Canada.
Funct Plant Biol. 2014 Apr;41(5):449-459. doi: 10.1071/FP13247.
Diatoms dominate nearly half of current oceanic productivity, so their responses to ocean acidification are of general concern regarding future oceanic carbon sequestration. Community, mesocosm and laboratory studies show a range of diatom growth and photophysiological responses to increasing pCO2. Nearly 20 studies on effects of elevated pCO2 on diatoms have shown stimulations, no effects or inhibitions of growth rates. These differential responses could result from differences in experimental setups, cell densities, levels of light and temperature, but also from taxon-specific physiology. Generally, ocean acidification treatments of lowered pH with elevated CO2 stimulate diatom growth under low to moderate levels of light, but lead to growth inhibition when combined with excess light. Additionally, diatom cell sizes and their co-varying metabolic rates can influence responses to increasing pCO2 and decreasing pH, although cell size effects are confounded with taxonomic specificities in cell structures and metabolism. Here we summarise known diatom growth and photophysiological responses to increasing pCO2 and decreasing pH, and discuss some reasons for the diverse responses observed across studies.
硅藻占据了当前近一半的海洋生产力，因此它们对海洋酸化的反应对于未来海洋碳固存而言受到普遍关注。群落、中尺度生态系统和实验室研究表明，硅藻对不断升高的pCO₂ 呈现出一系列生长和光生理反应。近20项关于升高pCO₂ 对硅藻影响的研究显示，其生长速率受到促进、无影响或受到抑制。这些不同的反应可能源于实验设置、细胞密度、光照和温度水平的差异，也可能源于特定分类群的生理特性。一般来说，用升高的CO₂ 降低pH值的海洋酸化处理在低至中等光照水平下会刺激硅藻生长，但与过量光照结合时会导致生长抑制。此外，硅藻细胞大小及其变化的代谢率会影响对不断升高的pCO₂ 和降低的pH值的反应，尽管细胞大小的影响与细胞结构和代谢中的分类特异性相互混淆。在这里，我们总结了已知的硅藻对不断升高的pCO₂ 和降低的pH值的生长和光生理反应，并讨论了各项研究中观察到的不同反应的一些原因。
