白石水库浮游植物的群落结构研究

为给白石水库生态环境保护和渔业可持续发展提供科学依据和基础资料,于2013年8月—2014年7月对白石水库的浮游植物群落结构,包括浮游植物的种类组成、优势种、密度、生物量、生物多样性和时空格局进行了周年研究。结果表明:白石水库共发现浮游植物239种,其中绿藻138种,硅藻39种,裸藻26种,蓝藻19种,甲藻8种,金藻、隐藻、黄藻各3种;主要优势种为小席藻Phormidium tenue、啮蚀隐藻Cryptomonas erosa、尖针杆藻Synedra acus;调查期间浮游植物密度为13.44×106cells/L,生物量为11.33 mg/L,优势类群为硅藻、隐藻和蓝藻;浮游植物群落结构有明显的时空分布规律,其中浮游植物密度呈现出夏季秋季春季冬季的变化规律,在空间分布上表现为凌河牤牛上游下游中游;根据浮游植物生物量的划分标准,白石水库属于富营养型水体;浮游植物均匀度指数为0.24~0.48,一周年的平均值为0.36,多样性指数为1.73~3.44,一周年的平均值为2.61。研究表明,白石水库目前处于中度污染状态,氮、磷对水库浮游植物的生长具有重要影响。

Community structure of phytoplankton in Baishi Reservoir

Phytoplankton community structure including species composition, dominant species, density, biomass, biodiversity , and spatial-temporal pattern of phytoplankton was monthly surveyed from August 2013 to July 2014 in order to provide scientific basis for sustainable water conservation and fisheries in Baishi Reservoir. Results showed that 239 phytoplankton species were found, including 138 species in Chlorophyta, 39 species in Bacillariophyta, 26 species in Euglenophyta, 19 species in Cyanophyta, 8 species in Pyrrophyta, 3 species in Chrysophyta, 3 species in Cryptophyta and 3 species in Xanthophyta, with dominant species Phormidium tenue, Cryptomonas erosa, and Synedra acus. There were phytoplankton density of 13. 44í106 cells/L, and the biomass of 11. 33 mg/L, with the dominant species in Bacillariophyta, Cryptophyta and Cyanobacteria. The phytoplankton had significant variation in spatial and temporal distribution in community structure, the order of density variation of phytoplankton as summer>autumn>spring>winter and as Linghe >Mangniu >upstream >downstream >midstream in spatial profile. Accord-ing to the criteria of the classification of phytoplankton biomass, Baishi Reservoir is within eutrophic, with evenness index of 0 . 24-0 . 48 , an average of 0 . 36 , diversity index of 1 . 73-3 . 44 , an average of 2 . 61 , indicating that the reservoir is moderately polluted due to nitrogen and phosphorus which have a significant impact on the growth of phytoplankton.