The Combined Effects of Increased pCO2 and Warming on a Coastal Phytoplankton Assemblage: From Species Composition to Sinking Rate
The Combined Effects of Increased pCO2 and Warming on a Coastal Phytoplankton Assemblage: From Species Composition to Sinking Rate
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DOI：
10.3389/fmars.2021.622319
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发表时间：
2021-03-24
影响因子：
3.7
通讯作者：
Hutchins, David A.
中科院分区：
文献类型：
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作者：
Feng, Yuanyuan;Chai, Fei;Hutchins, David A.
除了海洋酸化之外，中国沿海沃茨近期显著的变暖趋势也备受关注。然而，气候变暖和酸化对天然沿海浮游植物组合的综合影响的研究很少。对采自天津附近渤海海域的春季浮游植物进行了连续培养实验。实验处理使用温度（7和11摄氏度）和pCO（2）（400和800 ppm）处理的全因子组合。结果表明，pCO（2）和温度的变化对浮游植物的物种组成和元素化学计量有单独和交互作用。变暖主要有利于微微型浮游生物和甲藻生物量的积累。pCO（2）的增加显著增加了颗粒有机碳与颗粒有机磷（C：P）和颗粒有机碳与生物硅（C：BSi）的比值，降低了硅藻总丰度;同时，pCO（2）的增加显著增加了中心硅藻与羽状硅藻丰度的比值。升温和pCO（2）增加都大大降低了硅藻与甲藻的比例。叶绿素a生物量最高的高pCO（2），高温浮游植物组合，也有最慢的下沉速率的所有处理。总体而言，有显着的交互作用的影响增加pCO（2）和升温甲藻丰度，羽纹硅藻丰度，硅藻与甲藻的比例和中心与羽纹的比例。这些研究结果表明，未来的海洋酸化和变暖趋势可能会通过浮游植物物种组成和下沉率的变化，单独和累积地影响沿海生物地球化学和碳通量。
In addition to ocean acidification, a significant recent warming trend in Chinese coastal waters has received much attention. However, studies of the combined effects of warming and acidification on natural coastal phytoplankton assemblages here are scarce. We conducted a continuous incubation experiment with a natural spring phytoplankton assemblage collected from the Bohai Sea near Tianjin. Experimental treatments used a full factorial combination of temperature (7 and 11 degrees C) and pCO(2) (400 and 800 ppm) treatments. Results suggest that changes in pCO(2) and temperature had both individual and interactive effects on phytoplankton species composition and elemental stoichiometry. Warming mainly favored the accumulation of picoplankton and dinoflagellate biomass. Increased pCO(2) significantly increased particulate organic carbon to particulate organic phosphorus (C:P) and particulate organic carbon to biogenic silica (C:BSi) ratios, and decreased total diatom abundance; in the meanwhile, higher pCO(2) significantly increased the ratio of centric to pennate diatom abundance. Warming and increased pCO(2) both greatly decreased the proportion of diatoms to dinoflagellates. The highest chlorophyll a biomass was observed in the high pCO(2), high temperature phytoplankton assemblage, which also had the slowest sinking rate of all treatments. Overall, there were significant interactive effects of increased pCO(2) and warming on dinoflagellate abundance, pennate diatom abundance, diatom vs. dinoflagellates ratio and the centric vs. pennate ratio. These findings suggest that future ocean acidification and warming trends may individually and cumulatively affect coastal biogeochemistry and carbon fluxes through shifts in phytoplankton species composition and sinking rates.