合浦水库浮游植物及营养现状评价

Phytoplankton and its trophic levels in Hepu reservoir

于2006年10月-2007年7月对合浦水库浮游植物进行调查,通过浮游植物结合综合营养状态指数法对其营养现状进行评价。调查结果显示,合浦水库浮游植物共有6门90属,其中以绿藻门最多（49属）,其次为硅藻门（14属）,蓝藻门（13属）;浮游植物年平均数量为425.2×10^4ind·L^-1,生物量为5.06mg·L^-1;浮游植物的群落结构变化规律为冬季的硅藻型,到春季的硅藻-甲藻型,到夏季的蓝藻型,再到秋季的蓝藻-绿藻型;Shannon-Veaner指数表明,秋季的2^#、3^#和4^#站位,冬季的5^#站位,夏季的2^#、3^#、4^#、5^#站位均为富营养化水平,其他站位为中营养化水平,说明合浦水库整体已处于富营养化水平。综合营养状态指数监测结果显示,各站位的年均综合营养状态指数均大于50,为富营养化状态,这个结论支持了根据浮游植物数量和生物量的判断结果,表明合浦水库已处于富营养化状态。

An investigation of phytoplankton was carried out in Hepu reservoir from October 2006 to July 2007, and the trophic situation of phytoplankton was evaluated with comprehensive trophic level index method. The results showed that phytoplankton in Hepu reservoir had 90 Genus of six phyla, among them, Chlorophyta was the most （19）, and then Bacillariophyta （14） and Cyanophyta （13）. Annual mean amount of phytoplankton was 425. 2×10^4ind·L^-1 and biomass was 5.06mg/L, respectively. The variation orderliness of community structure of phytoplankton was as followed： diatom type in winter, diatom dinoflagellate type in spring, cyanobacteria in summer, and cyanophyta chlorophyta type in autumn. Shannon-Veaner＇s index suggested that these stations including 2 ^#, 3^# , 4^# in autumn, 5^# in winter, and 2^# , 3^# , 4^# , 5^# in s,ammer were eutrophers, the others were mesotrophers. It indicated that Hepu reservoir was in an eutrophers level. The annual comprehensive trophic level index of each station was above 50 and in an eutrophic state. This conclusion proved the results of phytoplankton amount and biomass, and indicated that Hepu reservoir was in an eutrophic state.