摘要
小型水库是华南沿海地区重要的城市供水水源。为了解小型水库的富营养化状况与浮游植物群落结构和季节动态之间的关系,于2006年4月、8月、12月采样测定了木头冲水库的环境因子(温度、pH、透明度、氮、磷营养盐浓度)和浮游植物群落结构。结果表明水体中总氮浓度的变化范围在0.34～0.7 mg.L-1之间,总磷浓度的变化范围在0.011～0.019 mg.L-1之间,透明度的变化范围在0.6～1.5 m之间,叶绿素a浓度的变化范围在9.18～21.1 mg.m-3之间,依据上述4个指标计算得出的TSIM指数在30～50之间变化,说明木头冲水库属中营养水体。浮游植物以适宜在中营养水体中生长的种类为主,3次采样共检出浮游植物52种(属),主要由在绿藻门和硅藻门的种类组成。浮游植物生物量的变化范围在4.17～5.38mg.L-1之间,春夏两季的生物量高于冬季。硅藻门的颗粒直链藻(Aulacoseira granulata)和绿藻门的单针藻(Monoraphidium sp.)是水体中春季的优势种类,夏季浮游植物的优势种为绿藻门的鼓藻(Cosmarium spp.)和硅藻门的颗粒直链藻,随着氮浓度的下降,拟柱胞藻(Cylindrospermopsis rackiborskii)成为水库冬季的优势种类。营养盐是木头冲水库浮游植物变化的主要影响因子。
Small reservoirs play an important role in city fresh drinking water supply in South China. In order to understand the dynamics of trophic state and phytoplankton community in these reservoirs, Mutouchong Reservoir located in Zhuhai City, a typical small reservoir with a volume of 0.508 106 m3, was investigated in April, August and December, 2006. The concentrations ofTN, TP and chlorophyll a ranged from 0.34 to 0.71 mg.L1, 0.011 to 0.019 mg＇L1, 9.18 to 21.1mg·m3, respectively, and SD ranged from 0.6 to 1.5m.Thc TSIM index, based on the above four factors, ranged from 40 to 50, and indicated that the Mutouchong Reservoirs was mcstrophic. 52 species were observed and most of them were from Bacillariophyta and Chlorophyta. The biomass of phytoplankton ranged from 4.17 mg.L-1 to 5.38 mg.L-1, and the biomass in spring and summer was higher than that in winter. Phytoplankton was primarily dominated by Aulacoseira granulate and Monoraphidium sp. in spring, and then by Cosmarium spp. and A. granulate, in summer. In winter, filamentous cyanobactcria, Cylindrospermopsis rackiborskii became the dominant species, and this was possibly related to the decrease of nitrogen. In Mutouchong reservoir, nutrient was one of the possible factors controlling the seasonal variation ofphytoplankton.
出处
《生态科学》
CSCD
2008年第2期71-76,共6页
Ecological Science
基金
珠海市科技局重大项目(PC20052040)
