青草沙水库浮游藻类群落组成及其与环境因子的关系

2014年1月至2015年12月逐月对上海水源地——青草沙水库进行浮游藻类调査研究。2014年发现优势种25种,2015年只有12种,两年均出现的优势种为:不定微囊藻(Microcystis incerta)、伪鱼腥藻属未定种(Pseudoanabaena sp.)、小环藻属未定种(Cyclotella sp.)、镰形纤维藻奇异变种(Ankistrodesmus falcatus var.mirabilis)和平壁克里藻(Klebsormidium scopulinum)。2015年较2014年种类数大幅减少,其季节变化也不如2014年明显,但总体上属夏秋季优势种种类多,冬春季则相对较少。优势种类群呈现夏秋季蓝藻多,春夏季绿藻多的特点,黄藻门和硅藻门的种类一般为冬春季优势种。冗余分析(RDA)显示,大多数优势种的密度主要与水温、溶解氧、总氮、总磷有关。重要优势种不定微囊藻密度与水温呈正相关关系,黄丝藻属未定种(Tribonema sp.)和小环藻属未定种密度与水温呈负相关关系。

Composition of planktonic algae community and its relationship with environmental factors in Qingcaosha Reservoir

Planktonic algae were investigated and researched monthly from January 2014 to December 2015 in Qingcaosha Reservoir, an important water source in Shanghai. There were 25 dominant species in 2014, and only 12 dominant species in 2015. Microcystis incerta, Pseudoanabaena sp., Cyclotella sp., Ankistrodesmus falcatus var. mirabilis and Klebsormidium scopulinum were common dominant species arising in two years. Compared with the data of 2014, the dominant species were substantially reduced in 2015, and the seasonal variation of dominant species was less obvious than in 2014. As a whole, the dominant species were more in summer and autumn than in winter and spring. The majority of dominant species groups was Cyanophyta and Chlorophyta. Dominant species groups showed the characteristics of more Cyanophyta in summer, autumn and more Chlorophyta in spring, summer. Algae of Bacillariophyta and Xanthophyta became dominant species more likely in spring and summer. Redundancy Analysis showed that water temperature, dissolved oxygen, total nitrogen, total phosphorus were the main environmental variables affecting most dominant species density. As for Microcystis incerta, the important dominant species, its density was positively related with water temperature. As for Tribonema sp. and Cyclotella sp., their density had negative correlation with water temperature.