南亚热带两座不同水文动态的水库浮游植物的功能类群演替比较

南屏、竹仙洞水库是珠海市拱北水厂的水源地,也是对澳门供水的主要水库。于2010年4月-2011年3月对这两座水库逐月采样,依据Padisák等（2009）功能类群方法对水样中浮游植物进行分类,不同的功能类群以不同的字母或字母与数字组合来命名。并结合水库的水文、水质及浮游植物生境特征,分析优势功能类群的演替动态及其主要环境影响因子。结果表明：南屏水库浮游植物功能类群演替具有明显的时间异质性。泽丝藻（Limnothrix sp.）、假鱼腥藻（Pseudanabaena sp.）等丝状蓝藻代表的S1功能类群与薄甲藻（Glenodinium sp.）代表的Y功能类群在6、7月份相对稳定水体中共同占优势,是南屏水库丰水期浮游植物演替的一个重要特征;而枯水期则主要以小环藻（Cyclotella sp.）、针杆藻（Synedra sp.）、颗粒直链藻（Aulacoseira granulata）等适应混合水体的C＋D＋P功能类群为优势群落。竹仙洞水库中几乎全年以C＋D＋P功能类群占优势,推测是因为竹仙洞水库水力滞留时间较短,利于耐冲刷的功能类群的生长。通过PCA（主成分分析）和RDA（冗余分析）探讨浮游植物功能类群演替与环境因子之间的关系,结果显示水力滞留时间、降雨量和正磷是影响南屏水库浮游植物功能类群演替的重要因子,而竹仙洞水库则是水力滞留时间和降雨量。两座水库的水力滞留时间差异明显,从而造成两座水库浮游植物功能类群组成及演替趋势的不同。

Comparative analysis of succession of the phytoplankton functional groups in two reservoirs with different hydrodynamics in Southern China

Nanping and Zhuxiandong reservoirs are the main reservoirs supplying drinking water to Zhuhai and Macau Cities. Phy- toplankton functional groups which could be screened by codon were identified monthly according to Padisak （2009） to make a comparative analysis of succession of the phytoplankton functional groups in the two reservoirs fxom April, 2010 to March, 2011. Hydrological, water quality and habitat characteristics of phytoplankton were considered to reveal the driving forces in selecting phytoplankton functional groups. The results showed that： Phytoplankton dynamics in Nanping reservoir exhibited a remarkable temporal heterogeneity. S 1 functional group （Limnothrix sp., Pseudanabaena sp.） and group Y （Glenodinium sp.） co-dominated dur- ing June and July in conditions of high water-column stability, which was the typical pattern in the seasonal dynamics of the phytop- lankton functional groups in Nanping reservoir. C＋D＋P functional groups （Cyclotella sp., Synedra sp. and Aulacoseira granulate） became more important during dry season in Nanping reservoir, while in Zhuxiandong reservoir they exhibited high relative bio- masses in the whole year, probably an outcome of short hydraulic retention time favouring those tolerant of water flush. Multivariate analysis （PCA and RDA） indicated the important role of hydraulic retention time, rainfall, dissolved phosphorus in affecting phytop- lankton succession in Nanping reservoir, and of hydraulic retention time and rainfall in Zhuxiandong reservoir. Hydraulic retention time was responsible in driving different seasonal succession of the phytoplankton functional groups between the two reservoirs.