抚仙湖叶绿素a的生态分布特征  

Ecological distribution characteristics of chlorophyll a in Fuxian Lake

作　　者：刘镇盛[1] 王春生[1] 倪建宇[1] 朱根海[1] 周怀阳[2] 

机构地区：[1]国家海洋局第二海洋研究所 [2]中国科学院广州地球化学研究所,广州510640

出　　处：《生态学报》2003年第9期1773-1780,共8页Acta Ecologica Sinica

基　　金：中国大洋矿产资源研究开发协会专项基金资助项目(DY95-06-08;DY105-02-01)~~

摘　　要：2001年5月、8月和9月,对云南抚仙湖水体、沉积物、沉积物与水界面的叶绿素a,浮游植物的优势种类、细胞密度的分布和时空变化及其与环境因子的关系进行了研究。采用分光光度法测定叶绿素a浓度。结果表明,水体叶绿素a浓度的分布存在着明显的季节变化,真光层中的动态变化尤其显著,且光照强度对水体中叶绿素a浓度的分布起主导作用。在观测的3个不同季节中,表层叶绿素a浓度,秋季最高,平均为(2.27±0.12)μg/dm3;春季次之,为(1.85±0.20)μg/dm3;夏季最低,为(1.38±0.15)μg/dm3。分析水体中营养元素的分布特征及其与叶绿素a之间的关系,表明磷是抚仙湖浮游植物生长的主要限制因子。沉积物叶绿素a浓度的垂直分布存在明显差异,其浓度在表层和次表层较高,并随沉积深度的增加而降低;浮游植物的分析表明,硅藻门的小环藻是抚仙湖沉积物中叶绿素a的主要来源。而上覆水中叶绿素a浓度与真光层叶绿素a浓度相当的原因,则可能是由水底微型藻类的再悬浮和浮游植物的沉降聚集而导致的。The investigations on chlorophyll a of the water body, sediment, sedimentwater interface were carried out in Fuxian Lake of Yunnan Province from May to September 2001. We have also analyzed the distribution of dominant species and cell density of phytoplankton, the spatial and temporal variation of chlorophyll a and its relationship with environmental factors. Chlorophyll a was extracted and measured according to procedures of UNESCO's spectrometer methods under 750nm, 664nm, 647nm, and 630nm wavelengths. Dissolved oxygen and nutrient data were supplied by the chemical working group of the research project. The results obtained show that there was seasonal variation of chlorophyll a concentrations in the water column, especially in the euphotic zone. The light intensity is one of the primary controlling factors of chlorophyll a distribution in the water. The highest chlorophyll a concentrations of the surface water occurred in autumn, with an average of (227±012)μg/dm3, while the lowest chlorophyll a concentrations appeared in summer with an average of (138±015)μg/dm3. The concentration of chlorophyll a in spring was (185±020)μg/dm3, higher than that in summer. Considering the distribution of the nutrients and their correlation with the chlorophyll a, it is evident that the phosphate was the major limitation factor of phytoplankton growth in Fuxian Lake. Moreover, there was markedly variation of the chlorophyll a in the different depth of lake sediment. Benthic chlorophyll a concentrations were high in the surface and subsurface, and decreased with increasing sediment depth. Based on the phytoplankton analysis, we suggest that the Cyclotella bodanica is the major source of chlorophyll a in sediments. The average chlorophyll a concentration was (145±042)μg/dm3 at the sedimentwater interface, which was similar to the concentration of the euphotic zone. High chlorophyll a concentration at sedimentwater interface was possibly due to the suspension of benthic

关 键 词：叶绿素A 浮游植物 生态分布 抚仙湖 

分 类 号：Q178.1[生物学—水生生物学]