铁对自然群落浮游植物生长的影响

Impact of Iron on the Growth of Natural Phytoplankton Community

利用室内加铁实验,研究了铁对胶州湾自然群落浮游植物生长的影响。实验结果显示,加入铁的浓度在5×10-8mol时,实验第7天的总细胞数量和叶绿素a含量分别比不加铁的对照组增加了5.9倍和3.7倍。加入铁的浓度增加10倍,达5×10-7mol时,浮游植物的生长速度更快,实验第5天的细胞数量和叶绿素a含量是对照组的34.9倍和16.1倍。浮游植物优势种中肋骨条藻(Skeletonemacostatum)在加铁浓度为5×10-7mol时,第5天达最高峰,而在加铁浓度为5×10-8mol和对照实验组,细胞数量达到高峰的时间推后了2d,新月菱形藻(Nitzschiaclosterium)在中肋骨条藻衰败后成为优势种。

The impact of enriched iron on the growth of natural phytoplankton community from the Jiaozhou Bay was studied in laboratory. It is shown from the experiment results that the total phytoplankton cell number and chlorophyll-a content with 5×10^(-8) mol of iron added on the seventh experimental day were 5.9 and 3.7 times more than those of the control group, respectively; the phytoplankton growth became faster when 5×10^(-7) mol of iron was added, and the total phytoplankton cell number and chlorophyll-a concent on the fifth experimental day was 34.9 and 16.1 times more than those of the control group, repectively. The cell number of the dominant species Skeletonema costatum with 5×10^(-7) mol of iron added reached the peak value on the fifth experimental day, but the cell number of Skeletonema costatum with 5×10^(-8) mol of iron added and of the control group reached their peak values on the seventh experimental day to postpone for two days. Nitzschia closterium became the dominant species after the decline of Skeletonema costatum.