浮游植物对不同紫色母岩净化景观水体效果的指示

为比较水体中浮游植物群落对不同紫色母岩净化景观水体效果的指示作用。选取重庆地区分布面积较广的蓬莱镇组（S1）、沙溪庙组（S2）、飞仙关组（S3）和遂宁组（S4）4种不同紫色母岩，将其灭菌后加入未灭菌的取自西南大学崇德湖的景观水体中，进行生态缸构建。测定水体理化性质、微量元素以及浮游植物群落结构。结果表明：利用浮游植物密度和功能群对景观水体水质的指示作用与利用水体理化指标的评价结果一致，而利用浮游植物生物量对景观水体水质的指示作用与利用水体理化指标的评价结果不符；对各组生态缸中水体元素和浮游植物优势功能群进行PCA分析，结果发现，水体中的部分微量元素与浮游植物的优势功能群Wo和X1呈现相关性。实验表明，浮游植物密度和浮游植物功能群可用于指示景观水体水质；相比于对照组，4组紫色母岩生态缸水体中的微量元素Cu、Mg可能通过对优势功能群Wo的抑制作用降低水体富营养化程度，具体机理需进一步研究。

Effect of different purple parent rocks on purifying landscape water by using phytoplankton as indicator

To compare the indicator function of phytoplankton on purifying landscape water using different purple parent rocks, four purple parent rocks were selected to build ecological cylinders. Physical and chemical parameters of water quality, as well as water elements and phytoplankton, were measured. The results showed that the indicator effects of density of phytoplankton and phytoplankton functional group on landscape water quality are the same as those based on physical and chemical parameters, while the indicator effects of phytoplankton biomass differ from those obtained by physical and chemical parameters. In addition, PCA analysis of trace elements and dominant functional groups of phytoplankton in each ecological cylinder showed that some of the trace elements are related to the dominant phytoplankton functional groups, Wo and X1. These results indicate that the density of phytoplankton and phytoplankton functional groups could be effectively used to indicate the quality of landscape water. Furthermore, trace elements Cu and Mg in the ecological cylinder composed of purple parent rocks could reduce the degree of eutrophication of landscape water by inhibiting the growth of the dominant phytoplankton functional group, Wo; however, further studies are required to elucidate the specific mechanisms underlying this aspect.