滇池的水华蓝藻的时空变化

 于2001年9月～2002年7月对滇池水华蓝藻进行了为期1 a的调查研究.结果表明,在滇池中形成水华的是微囊藻属(Microcystis Kutz.)和束丝藻属(Aphanizomenon Morr.).水华蓝藻总数为3 445 000～1 080 800 000 L^-1,年平均为130 866 603 L^-1,占浮游植物细胞总量的66.44%～90.66%.微囊藻属的数量为3 445 000～1 030 800 000 L^-1,年平均为125 174 582 L^-1,占浮游植物总数的35.69%～87.97%,是滇池浮游植物群落的单优势属.束丝藻属的数量为0～50 950 000 L^-1,年平均为5 692 021 L^-1,占浮游植物细胞总数的0.46%～30.75%.水华蓝藻数量的时空分布与微囊藻属一致,7月最高,1月最低;近岸带高于湖心,湖北部高于湖中部高于南部.束丝藻属的数量3月最高,1月最低;湖北部高于南部高于中部.微囊藻水华全年可见,束丝藻属仅在3月形成零星的小面积水华.

The temporal and spation variation of the cyanobacteria which caused the water bloom in the Dianchi Lake, Kunming, China

The results of an investigation and research into the cyanobacteria,which caused the water bloom in the Dianchi Lake from September 2001 to July 2002 is reported.The results showed that the cyanobecteria that caused the water bloom were Microcystis Kutz.and Aphanizomenon Morr.,and that the former was the dominant genus in the lake.The total concentration of the cyanobacteria causing water bloom was 3445000-1080800000 cell/L(cells per liter),and the annual concentration during this period was (130866603).These concentration of cyanobecteria which caused the water bloom accounted for 66.4%-(90.7%) of the total number of phytoplankton observed in the samples.The total concentration of genus Microsystis Kutz was 3445000-1030800000 cell/L,with annual average concentration of 123174582 cell/L,((35.7%-88.0%) of total concentration of phytoplankton).The density of Aphanizomenon was 0-5950000 cell/L,and the annual average concentration was 5692021 cell/L,(0.46%-30.75% of the total number of phytoplankton).The seasonal variation cyanobacteria causing the water bloom was as same as Microsystis Kutz.,that is the highest concentration was in July and the lowest in January.The presence of Microsystis Kutz.near the bank of the lake was higher than that in the center part,and also higher in the north than in the south.The density of Aphanizomenon Morr.was the highest in March and the lowest in January.Also the density of Aphanizomenon Morr.in the north part was higher than that in the south part of the lake,which was in turn higher than the center part of the lake.The water bloom of Microsystis Kutz.was observed during the whole year,but the water bloom of Aphanizomenon Morr.was only observed in March.