粤北2座不同营养水平水库浮游植物功能类群的季节演替

于2011年1—12月对广东省韶关市白水礤水库和苍村水库这2座中型居民供水水库进行每月1次、为期1a的采样,利用营养状态指数(TSI)进行水质综合评价,将水库中的浮游植物按功能类群进行分类,并结合水库的水文、水质和浮游植物的生境特征,分析全年优势功能类群的演替特点及其主要的环境影响因子。结果表明,白水礤水库为贫营养型水库,苍村水库为低中营养型水库,全年共检出浮游植物7门45属(种),可划分为16个功能类群,其中,白水礤水库全年以适应低营养盐环境的功能类群占优势,耐富营养化的功能类群仅在丰水期有检出;而苍村水库全年都能监测到耐富营养环境的功能类群,且在丰水期明显占优势,但在枯水期和平水期因营养盐含量的降低,演变为以适应低营养盐环境的功能类群为主。营养盐含量的不同是导致2座水库浮游植物功能类群产生差异的根本原因,而因降水季节的变化所致水体环境因子的变化则是造成2座水库浮游植物功能类群演替不可忽视的因素。

Seasonal Succession of Phvtoplankton Function Groups in Two Reservoirs Different in Eutrophic Level in Northern Guangdong Province, China

The Baishuica Reservoir and the Cangcun Reservoir,are two medium-sized reservoirs designated as sources of drinking water for residents in Shaoguan City,Guangdong Province.The reservoirs were sampled once every month throughout the year of 2011 for comprehensive evaluation of their quality using trophic status index(TSI),for classification of the phytoplanktons into functional groups,and for analysis of characteristics of the succession of dominant functional groups in the reservoirs throughout the year and their key environmental affecting factors.Results show that the Baishuica Reservoir is an oligotrophic aquatic system,while the Cangcun Reservoir an oligo-mesotrophic one.Throughout the year,45 genera of phytoplanktons under 7 phyla were collected and could be sorted into sixteen functional groups.In the Baishuica Reservoir,functional groups tolerant to low nutrient environments were in dominancy all the year around and only during the high water season could some eutrophication-tolerant functional groups be detected,while in the Cangcun Reservoir,eutrophication-tolerant functional groups were detectable all the year round and gained apparent dominancy during the high water season,but they were succeeded by the functional groups tolerant to low nutrient environments in dominancy during the low water and normal water seasons when nutrient contents were low.Variation of nutrient content in the water is the fundamental cause leading to succession of phytoplankton functional groups in dominancy,while changes in water environmental factors caused by changes in the rainy season are innegligible factors triggering the succession in the two reservoirs.