青海湖总磷、水温及矿化度与叶绿素a相关性分析

以青海湖水体11个样点为研究对象,测定水中叶绿素a含量,并对其分布特征及相关性进行分析.用叶绿素a来表征藻类,采用回归分析方法,对青海湖水中总磷、水温及矿化度与叶绿素a的关系进行探讨.结果表明:5月叶绿素a含量为0.396～4.031 mg·L-1,均值1.387 mg·L-1;7月叶绿素a含量为0.129-0.865 mg·L-1,均值0.432 mg· L-1;9月叶绿素a含量为0.164～1.360 mg·L-1,均值0.665 mg· L-1.5月至9月湖水总磷平均含量从0.124 mg· L-1持续下降到0.061 mg·L-1,藻类生长对总磷的需求大于外源输入和内源转化的总量,磷是青海湖藻类生长繁殖限制性营养元素之一,水温是春季限制藻类生长的主要因素.目前青海湖湖水矿化度在藻类生长的适宜范围内.

Analysis on the Correlation Between Total Phosphorus, Water Temperature, Mineralization and Chlorophyll-a in Qinghai Lake, China

The aim of present study was to explore the approches for assessing the effects of total phosphorus, water temperature and mineralization on alga growth in Qinghai Lake on basis of data analysis by 11 vertical sampling lines. In meanwhile, the chlorophyll-a contents and related distributions were detected, and relevant correlations were determined. The results showed that the chlorophyll-a contents were ranged from 0.396 mg·L-1 to 4.031 mg·L-1 with the mean value of 1.387 mg·L-1 in May, from 0.129 mg·L-1 to 0.865 mg·L-1 with the mean value of 0.432 mg·L-1 in July, and ranged from 0.164 mg·L-1 to 1.360 mg·L-1 with the mean value of 0.665 mg·L-1 in September. The average contents of total phosphorus continuously declined from 0.124 mg·L-1 in May to 0.061 mg·L-1 in September, as a result, the demand of total phosphorus for alga growth was greater than exogenous input and endogenous transformation. Therefore phosphorus, as one of crucial limiting nutrients for alga growth and reproduction in Qinghai Lake, but the water temperature was the main factor to limit alga growth in the period of spring time. At present, degree of mineralization in Qinghai Lake is right at a appropriate range for alga growth.