Department of Biological Oceanography, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, 1790 AB Den Burg, The NetherlandsDepartment of Ocean Ecosystems, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
J Phycol. 2012 Jun;48(3):559-68. doi: 10.1111/j.1529-8817.2012.01148.x. Epub 2012 May 4.
The combined effects of different light and aqueous CO2 conditions were assessed for the Southern Ocean diatom Proboscia alata (Brightwell) Sundström in laboratory experiments. Selected culture conditions (light and CO2(aq) ) were representative for the natural ranges in the modern Southern Ocean. Light conditions were 40 (low) and 240 (high) μmol photons · m(-2) · s(-1) . The three CO2(aq) conditions ranged from 8 to 34 μmol · kg(-1) CO2(aq) (equivalent to a pCO2 from 137 to 598 μatm, respectively). Clear morphological changes were induced by these different CO2(aq) conditions. Cells in low [CO2(aq) ] formed spirals, while many cells in high [CO2(aq) ] disintegrated. Cell size and volume were significantly affected by the different CO2(aq) concentrations. Increasing CO2(aq) concentrations led to an increase in particulate organic carbon concentrations per cell in the high light cultures, with exactly the opposite happening in the low light cultures. However, other parameters measured were not influenced by the range of CO2(aq) treatments. This included growth rates, chlorophyll a concentration and photosynthetic yield (FV /FM ). Different light treatments had a large effect on nutrient uptake. High light conditions caused an increased nutrient uptake rate compared to cells grown in low light conditions. Light and CO2 conditions co-determined in various ways the response of P. alata to changing environmental conditions. Overall P. alata appeared to be well adapted to the natural variability in light availability and CO2(aq) concentration of the modern Southern Ocean. Nevertheless, our results showed that P. alata is susceptible to future changes in inorganic carbon concentrations in the Southern Ocean.
实验室实验评估了不同光照和水 CO2 条件对南大洋硅藻 Proboscia alata（Brightwell）Sundström 的综合影响。选择的培养条件（光照和 CO2(aq)）代表了现代南大洋的自然范围。光照条件为 40（低）和 240（高）μmol 光子·m-2·s-1。三种 CO2(aq)条件范围从 8 到 34μmol·kg-1 CO2(aq)（分别相当于 pCO2 从 137 到 598μatm）。这些不同的 CO2(aq)条件引起了明显的形态变化。低 [CO2(aq) ]条件下的细胞形成螺旋，而高 [CO2(aq) ]条件下的许多细胞则解体。细胞大小和体积受到不同 CO2(aq)浓度的显著影响。随着 CO2(aq)浓度的增加，高光培养物中每个细胞的颗粒有机碳浓度增加，而在低光培养物中则恰恰相反。然而，其他测量参数不受 CO2(aq)处理范围的影响。这包括增长率、叶绿素 a 浓度和光合产量（FV /FM）。不同的光照处理对养分吸收有很大影响。与在低光照条件下生长的细胞相比，高光条件导致养分吸收速率增加。光照和 CO2 条件以各种方式共同决定了 P. alata 对环境变化的反应。总体而言，P. alata 似乎很好地适应了现代南大洋光照可利用性和 CO2(aq)浓度的自然变化。然而，我们的结果表明，P. alata 容易受到未来南大洋无机碳浓度变化的影响。
