讲座报告 Seminar
Luncheon Seminar #102: 多重环境变化对颗石藻和南海浮游植物群落固碳速率的相互影响  
Luncheon Seminar #102: Effects of multiple environmental factors on carbon fixation of coccolithophore and phytoplankton community of South China Sea
【时间 Time】:2018-4-9 (星期一) 11:40am-1:00pm Seminar starts at 12:00pm    【浏览次数 Count】:929   【发布时间 Updated】:2018-4-7
【地点 Venue】:周隆泉楼A3-206   A3-206 Zhou Long Quan Building
【主讲人 Speaker】:张勇,博士后    Yong Zhang
【来访单位 Institution】:MEL   
【邀请人 Host】:林昕  Xin Lin      【联络人 Contact】:黄迎   Ying Huang 2181571
Bio:
2008.092011.06 硕士,植物生理与分子生物学华中师范大学生命科学学院
2011.092015.10 博士,生物海洋学,德国亥姆霍兹基尔海洋研究中心(基尔大学)
2015.112016.01 博士后,生物海洋学,德国亥姆霍兹基尔海洋研究中心
2016.042018.04 博士后,海洋生物学,厦门大学近海海洋环境科学国家重点实验室(海洋与地球学院)
报告人主要从事环境因子如温度、碳酸盐系统参数(CO2pHDIC浓度)、光照强度和营养盐浓度对浮游植物生理特征影响的研究。申请人熟练掌握的研究方法有航次培养实验、实验室内微尺度围隔实验和单物种培养实验,研究兴趣聚焦在藻类光生理学和碳的海洋生物地球化学循环,研究对象包括蓝藻门铜绿微囊藻、绿藻门小球衣藻和金藻门赫氏颗石藻和大洋桥石藻。
 
Abstract:
CO2、温度、光、氮和磷是浮游植物生长的必需因子。不断升高的大气CO2浓度使海水CO2含量增加、全球变暖、海水温度上升和分层加剧,导致海洋上部混合层变浅,使分布于上部混合层的浮游植物接受到更多光强并降低深层海水向表层海水输送营养盐的速度。单个环境因子变化对浮游植物生理特征的影响会受到其他多个环境因子变化的调控。本报告首先展示CO2浓度、温度、光强、无机氮和无机磷浓度变化对钙化颗石藻生理特征的相互影响,之后探讨温度和CO2浓度对南海浮游植物群落固碳速率的相互影响。
在所有培养条件下,高浓度CO2抑制颗石藻的生长速率;高温增加藻细胞的生长速率;高浓度CO2、低浓度无机氮和无机磷协同降低颗石藻的生长速率。高浓度CO2和低浓度无机氮协同抑制藻细胞颗粒有机碳的生成速率;高光强和低浓度无机磷协同增加颗石藻藻细胞的颗粒有机碳含量。高温,高光强,低浓度无机氮和无机磷协同增加颗石藻的钙化速率。南海西部航次培养实验显示温度升高或CO2浓度增加促进浮游植物群落的固碳速率,但是温度升高和CO2浓度增加同时发生并没有协同增加浮游植物群落的固碳速率。高温降低外海海域浮游植物群落的叶绿素a浓度,但是没有显著影响近岸海域群落的叶绿素a浓度。这些实验结果建议:为了更好的理解功能型浮游植物类型响应海洋环境变化的生理生态特征,我们需要观察多重环境因子变化对浮游植物生理特征的相互影响以及探讨其内在机制。
CO2, temperature, light, N and P are necessary factors for growth of phytoplankton. Rising carbonate dioxide (CO2) levels in the atmosphere lead to increasing CO2 concentration and declining pH in seawater, as well as ocean warming. This enhances stratification and shoals the upper mixed layer (UML), hindering the transport of nutrients from deeper waters and affect light intensity exposed by phytoplankton. Effect of one environmental factor on physiological processes is modulated by other environmental factors. This report will show combined effects of CO2, temperature, light intensity, dissolved inorganic nitrogen (DIN) and phosphate (DIP) concentrations on physiological rates of coccolithophore, and effects of rising temperature and CO2 on photosynthetic carbon fixation of phytoplankton community in western South China Sea.
In all incubations in the laboratory, high temperature increased growth of coccolithophore and high CO2 level inhibited growth of coccolithophore. High CO2 level, low dissolved inorganic nitrogen and phosphate concentrations synergistically reduced growth rates of coccolithophore. High light intensity and low dissolved inorganic phosphate concentration increased particulate organic carbon quota. High temperature, high light intensity and low nutrient concentrations synergistically increased calcification rates of coccolithophore.
In the shipboard culture experiment, rising temperature and CO2 individually increased primary productivity of phytoplankton assemblages in all sites, whereas high temperature and high CO2 level did not increase primary productivity synergistically. Rising temperature increased primary productivity at low CO2 level whereas decreased primary productivity at high CO2 level. High temperature decreased the Chl a concentrations in the off-shore waters at low CO2 level, and did not affect Chl a concentrations in the coastal waters at both LC and HC conditions. These results suggest that we should investigate the combined effects of changes in multiple environmental factors on physiological rates of phytoplankton and the mechanisms behind physiological processes in order to understand the responses of phytoplankton functional groups to marine environmental changes.