南太湖入湖口蓝藻生物量与TN、TP的年变化特征及相关性研究

ANNUAL VARIATIONS OF BLUE ALGAE BIOMASS AND TN AND TP LEVELS AND THEIR CORRELATION AT DIFFERENT INLET AREAS OF SOUTH TAIHU LAKE

采用统计学方法,对南太湖水域三个入湖口(小梅港、新塘港、大钱港)水质中蓝藻生物量、TN和TP的年变化特征进行了调查;通过SPSS10.0软件对蓝藻生物量与TN和TP的相关性进行了分析。结果表明:(1)南太湖入湖口蓝藻生物量一般有两个高位期,分别出现在每年的5—6月和9—10月;(2)南太湖入湖口的TN和TP处于富营养化水平,TN有朝重富营养化发展的趋势;(3)2008—2009年蓝藻生物量与TN的相关性系数r介于-0.010—0.210之间,呈现不相关;2010年r介于0.43—0.47,呈现低度负相关;(4)3年中蓝藻生物量与TP的相关性系数r介于0.30—0.80,呈现正相关。南太湖沿岸TP出现在0.05—0.20mg/L范围内频率达90%以上,蓝藻高位期时TP浓度在0.1—0.15mg/L范围。结果说明,南太湖沿岸水体中氮和磷营养盐水平较高,已经不容忽视,蓝藻生物量与TN之间存在一定的此消彼长规律,水体中TP已经是南太湖各入湖口蓝藻生长繁殖的相关性因子。

Annual variations of blue algae biomass, TN and TP level at Xiaomei, Xintang and Daqian inlet areas of south Taihu Lake were determined and analyzed by statistical method. The correlation between the blue algae biomass and TN or TP was analyzed by SPSS 10.0 （SPSS inc., Chicago, U.S.）. The results showed that： （1） the blue-green algae bio- mass at different inlet areas had two high-level outbreak periods, respectively was in the annual May-June and Septem- ber-October; （2） the concentrations of TN and TP had reached eutrophic-level and the nutrition level of TN was gradually tending to higher eutrophic-level; （3） the correlation coefficient （“r” for short） between blue algae biomass and TN con- centration was -0.010--0.210 from 2008 to 2009 which showed that it was no correlation, however, the “r”was -0.43-- -0.47 in 2010 which showed that it was low negative correlation in this year; （4） the “r”between blue algae biomass and TP concentration was 0.30--0.80 which showed that it was positive correlation. The frequency of TP concentration which was from 0.05 to 0.20mg/L had reached 90%, it would reach 0.10--0.15mg/L when it was under the high-level outbreak period of blue algae. According to all the results, it could conclude that the nitrogen and phosphorus nutrition in the south of Taihu Lake have been very higher than ever so that it could not be neglected by people. Blue algae biomass would in- crease when TN concentration decrease and vice versa. TP concentration in the south of Taihu Lake has become the related factor on the growth and reproduction of blue algae.