摘要
利用Ludox-QPS方法并结合沉积环境因子的综合分析,研究了2011年4月采自长江口及东海10个站位以底栖硅藻、纤毛虫和异养小鞭毛虫为代表的微型底栖生物及小型底栖生物的组成、丰度和生物量、分布及生态特点。结果表明,底栖硅藻的丰度(5.92×104个/10 cm2)和生物量(83.29!g C/10 cm2)远高于纤毛虫(丰度为1036个/10 cm2,生物量为3.33!g C/10cm2)、异养小鞭毛虫(丰度为4451个/10 cm2,生物量为2.51!g C/10 cm2)和小型底栖生物(丰度为(1947±849)个/10 cm2,生物量为(49.01±22.05)!g C/10 cm2)。在鉴定出的11个小型底栖生物类群中,线虫占小型底栖生物总丰度的90%和总生物量的37%。底栖硅藻生物量在长江口及东海海域呈由近岸向外海逐渐降低的分布特点,而底栖纤毛虫、异养小鞭毛虫及小型底栖生物的分布则正相反。在垂直分布上,76%的硅藻和80%的线虫分布在0—2 cm沉积物表层,仅1%的硅藻和6%的线虫分布在5—8 cm分层。统计分析表明,底栖硅藻的现存量与沉积物中叶绿素a含量呈极显著的正相关,与底层水温度呈弱的正相关;该海域底栖原生动物和小型底栖生物的分布受多个因子而非单一环境因子的共同作用。对比分析表明,长江口及东海单位体积沉积物中的硅藻丰度较水体中的硅藻丰度高2个数量级,沉积物中相当部分的叶绿素a含量可能系底栖硅藻所贡献;表层8 cm沉积物中纤毛虫的丰度约是上层30 m水柱中纤毛虫丰度的30倍,生物量约是后者的40倍。尽管纤毛虫在生物量上远小于小型底栖生物,但其估算的生产力约是后者的3倍;而异养小鞭毛虫由于个体更小,其周转率可能较纤毛虫更高。长江口及东海陆架区原生动物和小型底栖生物的高现存量及生产力预示着其在该海域生态系统中的重要作用。
Using the newly developed Ludox-QPS method, we investigated the community composition, abundance and biomass, and distribution of benthic diatoms, ciliates and heterotrophic microflagellates （HMF） and meiobenthos in combination with the analysis of benthic environmental variables at ten stations in the Changjiang （Yangtze） Estuary and East China Sea in April 2011. The benthic diatoms were dominant both in the abundance （5.92×104 ind/10 cm2） and biomass （83.29 μg C/10 cm2）, followed by benthic ciliates （abundance： 1036 ind/10 cm2, biomass： 3.33 μg C/10 cm2） and HMF （4451 ind/10 cm2, 2.51 μg C/10 cm2）. The abundance of meiobenthos in the upper 8 cm of sediments was （1947±849） ind/10 cm2 and the biomass was （49.01±22.05） μg C/10 cm2. Among the 11 meiobenthos groups identified, nematodes accounted for 90% of the total abundance and 37% of the total biomass. The biomass of benthic diatoms was distinctly higher in the coastal region than that in the offshore area, while the distribution pattern of benthic ciliates, HMF and meiobenthos was exactly opposite. On average 76% of diatoms and 80% of nematodes were distributed in the 0-2 cm sediment layers, while the respective proportions were only 1% and 6% in the 5-8 cm layers. Statistical analyses showed that the standing crops of benthic diatoms had significantly positive correlation with sediment chlorophyll-a contents and weak positive correlation with bottom water temperature, and benthic protozoa and meiobenthos might be structured by the interaction of multiple rather than single environmental variables. Our data indicate that the density of benthic diatoms in the sediments was very high, about two orders magnitude higher per unit volume than that in the water column of the Changjiang Estuary and East China Sea, where a great proportion of sediment chlorophyll a was contributed by benthic diatoms. The benthic ciliate abundance in the upper 8 cm of sediments were 30 times higher and the biomass was 40 times higher than those
出处
《生态学报》
CAS
CSCD
北大核心
2013年第21期6813-6824,共12页
Acta Ecologica Sinica
基金
国家重点基础研究发展计划(973)项目(2011CB403604)
中国科学院知识创新工程重要方向项目(KZCX2-EW-Z-5)
中国科学院海洋研究所"一三五"专项资助项目(2012IO060104)
关键词
微型底栖生物
小型底栖生物
现存量
分布
长江口
东海
microbenthos meiobenthos standing crops distribution changjiang estuary east China Sea
