青草沙水库浮游植物群落特征与水环境因子的典范对应分析

Community Structure of Phytoplankton and Their Canonical Correspondence Analysis with Environmental Factors in Qingcaosha Reservoir

摘要: 为揭示青草沙水库浮游植物群落结构特征及其与水环境因子的关系，于2014年1月至 2014年11月，逐月对青草沙水库12个位点浮游植物种类组成、种群细胞密度及12项水体理化指标进行了调查分析。结果表明：调查期间共检出浮游植物8门88属207种，主要优势种有颗粒直链藻(Aulacoseira granulate)、颗粒直链藻最窄变种(Aulacoseira granulate var. angustissima)、变异直链藻(Melosira varians)、梅尼小环藻(Cyclotella meneghiniana)、卵形隐藻(Cryptomonas ovata)、尖尾蓝隐藻(Chroomonas acuta)、微小色球藻(Chroococcus minutus)、点形平裂藻(Merismopedia punctata)和铜绿微囊藻(Microcystis aeruginosa)等。浮游植物群落组成以硅藻为主，蓝绿藻其次；浮游植物细胞密度季节差异大，6月最高，为2.81 × 10⁶ cells/L，1月最低，为2.19 × 10⁵ cells/L，全年Margalef指数、Pielou指数及Shannon-Wiener指数分别为3.50 (±0.74)、0.35 (±0.17)及2.41 (±0.72)，利用TLI(∑)指数综合评价青草沙草水体处于轻度富营养化状态。青草沙水库浮游植物群落结构变化规律为冬季隐–硅藻型、春季硅–绿藻型、夏季硅–蓝藻型、秋季蓝–硅藻型。水库浮游植物空间差异较大，库区中后部多样性明显高于前部。典范对应分析(CCA)表明，温度、溶解氧、pH、总氮和总磷与青草沙水库浮游植物群落结构关系最为密切。

Abstract: In order to reveal the community structure characteristics of phytoplankton and the relationships with environmental factors in Qingcaosha Reservoir, the phytoplankton species composition, abundance and 12 environmental factors at 12 sampling sites were analyzed from January 2014 to November 2014. A total of 207 phytoplankton species were identified, which belong to 88 genera and 8 phyla. The dominant species were Aulacoseira granulata, Aulacoseira granulate var. angustissima, Cyclotella meneghiniana, Cryptomonas ovate, Chroomonas acuta, Chroococcus minutus, Merismopedia punctata and Microcystis aeruginosa, etc. Phytoplankton species in Qingcaosha Reservoir were mainly composed by Bacillariophyta, Chlorophyta and Cyanophyta. Phytoplankton abundance varied seasonally with the maximum value (2.81 × 10⁶ cells/L) in June and minimum (2.19 × 10⁵ cells/L) in January. Mean Margalef index, Pielou index and Shannon- Wiener index were 3.50 (±0.74), 0.35 (±0.17) and 2.41 (±0.72). The phytoplankton community structure was of Cryptophyta-Bacillariophyta type in winter, of Bacillariophyta-Chlorophyta type in spring, of Bacillariophyta-Cyanophyta type in summer and of Cyanophyta-Bacillariophyta type in autumn. Phytoplankton spatial differences are large, the diversity of front portion was significantly higher than the rear reservoir area. Canonical correlation analysis (CCA) showed that temperature, dissolved oxygen, pH, total N and total P had the closest relationships with the phytoplankton community structure in the reservoir.