南极中山站近岸海冰生态学研究Ⅰ．1992年冰藻生物量的垂直分布及季节变化

从１９９２年４月至１２月对东南极中山站近岸当年冰生物量及其环境因子进行了观测。冰底有色层出现在４月下旬和１１月下旬，集中于冰底２～３ｃｍ，叶绿素ａ最高含量分别为８８．３ｍｇ／ｍ３和２８１０ｍｇ／ｍ３，相应的冰藻数量分别为３．５×１０６和１．２１×１０８个／升。柱总叶绿素ａ含量的季节性变化极为显著，尤其是以春季的大幅度快速增值为特征，变化范围为１．１７～５９．７ｍｇ／ｍ２，冰藻生物量主要分布在冰底，冬季期间则集中在冰底或冰的中上层。藻类优势种较为单一，秋季优势种为Ｎｉｔｚｓｃｈｉａｌｅｃｏｉｎｔｅｉ、Ｎ．ｂａｒｋｌｅｙｉ和Ｎ．ｃｙｌｉｎｄｒｕｓ；春季优势种为Ａｍｐｈｉｐｒｏｒａｋｊｅｌｍａｎｉ，Ｂｅｒｋｅｌｅｙａｒｕｔｉｌａｎｓ和Ｎ．ｌｅｃｏｉｎｔｅｉ。中山站近岸冰藻生物量的垂直分布和季节变化以及春季优势种的组成与东南极其它固冰区具有较强的相似性，与亚南极固冰区差异较大。

VERTICAL AND SEASONAL VARIATIONS IN BIOMASS OF ICE ALGAE IN THE VICINITY OF ZHONGSHAN STATION,ANTARCTICA

The ice algae communities at three sites near Zhongshan Station (69°22′24″S,76 °22′40″E),east Antarctica were monitored from April to December 1992. The maximum ice thickness was 1.74m in November and covered snow was less than 30cm in depth through the year. 2 or 3cm brown layers occurred in the bottom ice in later April and November,with highest chlorophyll a values of 88.3 and 2810mg/m 3 respectively,and the comparing cell numbers were 3.5×10 6 and 1.21×10 8cells/l. The maximum integrated chlorophyll a value was 59.7mg/m 2 in November and the values had never exceeded 6mg/m 2 before mid October. Most of the biomass occured in the bottom ice and more than 95 percent of it was concentrated in the bottom 15cm ice layer during ice algae bloom. The dominant diatoms included Nitzschia lecointei,N. barkleyi and N. cylindrus in austral autumn,and Amphiprora kjellmanii,Berkeleya rutilans,Nitzschia lecointei in austral spring,and had some difference depending on the sites and environmental conditions. The results show that the composition of dominant species of ice algae and the biomass in austral spring were similar to that of other fast ice sites in east Antarctica but very different from that of sub Antarctica.