| 摘要: |
| 2007 年11 月于长江口邻近海域通过在不同光照强度下往培养水体添加不同量的磷酸盐(或硝酸盐)进行现场培养实验, 对培养过程中叶绿素a 质量浓度变化以及比生长速率与氮磷浓度之间的关系进行了研究。结果表明: 无光照下叶绿素a 没有增加趋势, 其他光照下浮游藻类生长有着很长的平台期,且100%光照下叶绿素a 终浓度可以为80%、60%、40%、20%光照下的1.5 倍、2 倍、4 倍、15 倍; 相同光照下, 叶绿素a 质量浓度在不同营养盐水平之间差异不明显, 浮游藻类生长主要受光照的限制,而不是营养盐; 培养介质中磷酸盐和硝酸盐浓度与浮游藻类比生长速率之间有一个临界点, 当氮磷浓度超过阈值时, 浮游藻类比生长速率会减小, 其中磷酸盐的阈值浓度约为1~2 μmol/L, 硝酸盐阈值约为20~25 μmol/L。 |
| 关键词: 光照 磷酸盐 硝酸盐 比生长速率 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金青年科学基金项目(40906054); 淮海工学院江苏省海洋生物技术重点建设实验室研究基金项目(2010HS12); 淮海工学院引进人才科研启动基金资助项目(KQ09016); 上海市自然科学基金项目(10ZR1408900); 江苏省环保厅项目(2010043) |
|
| Response of phytoplankton to phosphate or nitrate added under different irradiance |
|
|
| Abstract: |
| In situ incubation experiments were conducted to investigate the variations of chlorophyll a concentration and relation between phosphate or nitrate concentration and specific growth rate controlled by the addition ofphosphate or nitrate under different irradiance in adjacent sea of Changjiang Estuary in November, 2007. the results showed that phytoplankton growth had a long stationary phase under all the controlled irradiance except absence of natural irradiance, and the peak of chlorophyll a under 100% of natural irradiance was 1.5, 2, 4, 15 times of that under 80%, 60%, 40%, 20% of natural irradiance, respectively, and variations of chlorophyll a in different phosphate or nitrate levels were similar, so that the phytoplankton growth was limited by the irradiance instead of the nutrient. Moreover, the phosphate and nitrate both had a threshold concentration affecting algal specifice growth rate, and the phosphate threshold concentration was between 1~2μmol/L while the nitrate threshold concentration was between 20~25 μmol/L. |
| Key words: irradiance phosphate nitrate specific growth rate |
