鄱阳湖丰水期水体中叶绿素a含量空间分布及其与环境因子的关系  

Spatial Distribution of Chlorophyll a in Poyang Lake during Wet Season and Its Relationship with Environmental Factorsand Factors

作　　者：吴召仕[1,2] 张路[1] 刘宝贵[1,2] 陈宇炜[1] 

机构地区：[1]中国科学院南京地理与湖泊研究所、湖泊与环境国家重点实验室,江苏南京210008 [2]中国科学院大学,北京100049

出　　处：《湿地科学》2014年第3期286-292,共7页Wetland Science

基　　金：国家重点基础研究发展计划项目(2012CB417005);江西省科技重大专项项目(20114ABG01100)资助

摘　　要：在2011年8月和2012年7月丰水期,在鄱阳湖湖区布设77个采样点,大规模采集水样,研究浮游植物生物量(以水体中叶绿素a含量表示)在湖区的空间分布,并探讨叶绿素a与相关环境因子之间的关系。结果表明,鄱阳湖丰水期水体中叶绿素a质量浓度较低,平均值为10.58μg/L;叶绿素a含量的空间分布特征为:东南湖区最高,中部湖区居中,北部通江区较低。Spearman秩相关分析结果表明,水体中叶绿素a含量与水体透明度显著正相关,与总悬浮颗粒物含量、总氮含量、亚硝态氮含量、硝态氮含量和溶解性总氮含量显著负相关,与其他营养盐含量不相关。水下光照条件是限制鄱阳湖浮游植物丰水期生长的主要因素;鄱阳湖水体交换时间较短,也在一定程度上抑制了浮游植物的生长;丰水期,高水位稀释了水体中的营养盐浓度,从而掩盖了其对浮游植物的作用,导致营养盐的作用不明显。With a watershed area of 1.622×10^5 km^2, Poyang Lake is the largest freshwater lake in China connecting to the Yangtze River. The lake area during the wet season was much larger than that during the dry season. In addition, the water level is in balance between the Yangtze River and the lake during the wet season, which causes the lake relatively stable. Therefore samplings were conducted in Poyang Lake during the wet season （August in 2011 and July in 2012）, with a wide coverage （77 sampling sites in total）. The primary objective was to illustrate the spatial distribution of phytoplankton biomass （measured as chlorophyll a concentration） in Poyang Lake on the whole lake scale, especially in areas which were less well studied before. Additionally, we also considered the relationships between the chlorophyll a and responsible environmental factors, such as secchi depth, suspended solids and nutrients, in order to examine the effect of environmental factors on the growth and distribution of phytoplankton in Poyang Lake. The chlorophyll a concentration in Poyang Lake was relatively low, with the averaged of 10.58 μg/L, even though the nutrient concentrations were relatively high （mean concentration of total nitrogen was 1.38 mg/L and mean concentration of total phosphorus was 0.07 mg/L）. Spatially, the chlorophyll a concentrations increased from the north region through the middle region, and achieved the highest in the southeast part of the lake. The results of Spearman correlation analysis showed that the chlorophyll a concentration was closely related to the underwater light condition, i.e., significantly positive correlated with the water transparency （r = 0.273, p = 0.002）, and significantly negative correlated with suspended solids （r = -0.254, p = 0.004）. Regarding nutrients, the chlorophyll a concentration was significantly negative correlated with the concentrations of total nitrogen, dissolved total nitrogen, nitrogen dioxide and NO3, but was not significantly correlated with oth

关 键 词：浮游植物 丰水期 光照 营养盐 水体交换时间 鄱阳湖 

分 类 号：X524[环境科学与工程—环境工程]