| 摘要: |
| 在全球气候变化的背景下,极端天气频发,海洋生物也将受到环境异质性的影响,即环境条件基于平均水平的震荡变化。为研究温度波动变化对海洋碳循环中的重要种群颗石藻的影响,采用半连续培养的方式对海洋颗石藻优势种赫氏颗石藻(Emiliania huxleyi)的非钙化株系与钙化株系分别进行模拟培养实验,探究颗石藻在低(20℃)和高(25℃)平均温度下对升温及温度波动变化的响应。结果表明,升温与温度波动对两株E.huxleyi的生长均起到了抑制作用,而升温和温度波动变化对两株E.huxleyi的生长速率以及胞内碳水化合物含量、非钙化株系的颗粒有机碳含量及钙化株系的蛋白质和颗粒物无机碳含量、碳氮比及沉降速率产生了显著的交互效应,温度的波动变化在一定程度上增强了颗石藻应对升温的适应性。通过对两株系的生理响应结果进行对比分析,发现非钙化株系各生理参数对升温和温度波动变化更为敏感,表明颗石藻的钙化作用可能对其应对环境波动下的极端环境条件起缓冲保护作用。升温和温度波动变化显著削弱了颗石藻的沉降速率,可能会对颗石藻相关的海洋碳沉降与输出产生显著的削弱效应。因此,为了更准确地预测海洋颗石藻对气候变化的响应,未来相关研究需要考虑叠加在升温基础上的温度波动变化对颗石藻的生理生态学效应。 |
| 关键词: 颗石藻 海洋变暖 温度波动 钙化作用 株间效应 |
| DOI：10.11693/hyhz20220500122 |
| 分类号:Q948 |
| 基金项目:国家自然科学基金,41676160号;天津市自然科学基金项目,1JCYBJC22900号;上海市极地前沿科学研究基地资助项目。 |
附件 |
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| STRAIN SPECIFIC RESPONSES OF COCCOLITHOPHORE EMILIANIA HUXLEYI TO WARMING AND TEMPERATURE FLUCTUATION |
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WANG Ya-Nan1,2, FENG Yuan-Yuan2,3,4, LI Tong-Tong1, CAI Ting5, BAI You-Cheng5
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1.College of Marine and Environmental Sciences, Tianjin University of Science and Technology, Tianjin 300457, China;2.School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China;3.Shanghai Polar Frontier Scientific Research Base;4.Shanghai 200030, China;5.Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China
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| Abstract: |
| Under global climate change, with increased frequency of extreme weather, marine organisms are also affected by environmental heterogeneity—the fluctuation of environmental conditions based on average level. Therefore, the strain-specific effects of temperature fluctuation on coccolithophores was studied by conducting a semi-continuous incubation on a non-calcified and a calcified strain of coccolithophore Emiliania huxleyi, an important role player in marine carbon cycle. The physiological responses of the two strains to ocean warming and temperature fluctuation at low (20 ℃) and high (25 ℃) mean temperatures were examined. Results suggest that the temperature increase and fluctuation inhibited the growth of E. huxleyi, while significant interactive effects of temperature increase or fluctuation on growth and cellular carbohydrate content of two strains of E. huxleyi, PIC content of non-calcified E. huxleyi, and protein and PIC contents of calcified E. huxleyi were observed. Temperature fluctuation enhanced the adaptability of coccolithphores in response to an elevated temperature. Comparison between the physiological responses of the two strains reveals that the physiology of non-calcified strain was more sensitive to warming and temperature fluctuation, indicating that the calcification of coccolithophores may play a protective role in an extreme environment change. Warming and temperature fluctuation significantly decreased the sinking rate of coccolithophores, suggesting a weakened carbon export by coccolithophores in a warmer and temperature fluctuating environment. Therefore, to precisely predict the response of marine coccolithophores to climate change and the biogeochemical feedbacks, the effects of temperature fluctuation should be considered. |
| Key words: coccolithophores ocean warming temperature fluctuations calcification strain specific responses |
