粤北2座饮用水源地水库的富营养化与浮游植物群落动态

粤北地区的水库以山地型水库为主,其中有不少担负着饮用水源的功能。为了解粤北地区水源地水库的富营养化状态与浮游植物种群的动态变化,于2011年的枯水期（2―3月）和丰水期（6―7月）对花山和白水礤2座中型水库进行了采样调查,对水库的营养盐和浮游植物种群进行了分析。结果表明：2座水库均为贫营养型;浮游植物在枯水期和丰水期的种类变化不大,共鉴定出的浮游植物6门37种（属）,以硅藻为主要优势种群,优势种为小环藻（Cyclotella sp.）和颗粒直链藻（Melosira granulata）。同时,枯水期和丰水期2座水库浮游植物的丰度和生物量都比较低,其值分别为0.65×106～1.95×106cells.L-1、0.11 mg.L-1和0.73×106～8.9×106cells.L-1、0.05～0.50 mg.L-1。在浮游植物种群动态中,2座水库浮游植物丰度和生物量的季节变化主要表现为硅藻丰度和生物量的变化,低浓度的氮、磷营养盐限制是影响这2座贫营养水库浮游植物动态变化主要因素。

Eutrophication and dynamics of phytoplankton community in two reservoirs for drinking water supply in northern Guangdong province, China

There are many reservoirs in the northern mountains of Guangdong province,which have been used for drinking water supply.In order to understand the eutrophication and the dynamics of phytoplankton community in such reservoirs,two reservoirs（Huasan and Baishuizhai Reservoirs） were investigated in the dry（February and March） and wet（June and July） seasons of 2011.The results showed that the two reservoirs were oligo-mesotrophic,without significant difference in phytoplankton composition between the wet and dry weather seasons.In total,37 phytoplankton species were observed,dominated by Melosira granulate,Cyclotella meneghiniana and Peridinium bipes.The abundance and the biomass of phytoplankton were relatively low.The abundance of phytoplanktons ranged from 0.65×106to 1.95×106cells.L-1in the dry season,and 0.73×106to 8.9×106cells.L-1in the wet season;the biomass of phytoplanktons ranged from 0.11 to 0.11 mg.L-1in the dry season,and 0.05 to 0.50 mg.L-1in the wet season.As far as the phytoplankton population dynamics concerned,the changes in abundance and biomass were manly determined by diatom that was limited by low concentrations of nitrogen and phosphorus in the two reservoirs.