水利开发对二滩水库浮游植物及水质状况季节性影响

Effect of Development of Water Conservancy on Seasonal Community Structure of Phytoplankton and Water Quality of Ertan Reservoir,Sichuan Province

2010—2014年连续5a(春季、夏季、秋季、冬季)对四川二滩水库进行浮游植物及水质定点采样调查,研究水利开发对浮游植物种类组成、数量特征、群落多样性及水质状况的影响。结果表明:(1)水利开发区共检出浮游植物7门251种,绿藻门(Chlorophyta)90种,所占比例为35.86%,对照区共检出浮游植物7门166种,绿藻门68种,所占比例为40.96%,水利开发区和对照区浮游植物种类在夏季和秋季较高,春季和冬季较低;(2)二滩水库水利开发区和对照区浮游植物Shannon-Wiener多样性指数(H)、Pielou均匀度指数(JP)、Margalef种类丰富度指数(S)在夏季和秋季较高,春季和冬季较低,随季节呈先增加后降低趋势,而浮游植物密度(D)在秋季最低,不同季节浮游植物密度和丰富度指数均表现为水利开发区显著或者极显著高于对照区,多样性指数和均匀度指数均表现为对照区极显著高于水利开发区(p<0.01);(3)水利开发区和对照区水温、pH,TN,NH+4-N,TP,高锰酸钾指数,BOD5和CODcr浓度呈一致的变化规律,随季节的变化呈先增加后降低趋势,秋季最高,春季和冬季较低,其中水温在夏季最高,透明度随季节变化呈"V"字形规律,在春季最高,秋季最低,而水温和TP浓度在水利开发区和对照区并没有明显差异;不同季节pH,TN,NH+4-N,高锰酸钾指数,BOD5和CODcr浓度均表现为水利开发区高于对照区,局部有所波动,在冬季二者的差异不明显,说明了水利开发对二滩水库冬季水质的影响较小;(4)相关性分析表明二滩水库浮游植物群落多样性与水温和TN浓度呈显著或极显著正相关,与pH呈显著负相关,说明pH、水温和TN含量是影响二滩水库浮游植物多样性的主要因素。

Studies on the effect of development of Ertan reservoir water conservancy on seasonal community structures of phytoplankon and water quality,including species richness,density and biodiversity indices,and correlation analysis between community index of phytoplankton and water quality parameters were carried out from 2010 to 2014.The results indicated that：（1）251species of algae were found in water conservancy development zone,of which 35.86% were Chlorophyta,and 166 species of algae were found in CK zone,of which 40.96% were Chlorophyta,there was great seasonal variation in phytoplankton which showed the species were greater in summer and autumn than those in spring and winter;（2）the Shannon-wiener diversity index（H）,evenness index（JP）and richness index（S）of water conservancy development zone and CK first increased and then decreased with the change of season,which showed these indices were higher in summer and autumn than those in spring and winter,while the density of phytoplankton was the lowest in autumn,the density and richness index of phytoplankton in different seasons showed the sequence：water conservancy development zoneCK,while Shannon-wiener diversity index and evenness index presented the opposite trend;（3）the water temperature,pH,TN,NH＋4-N,TP,potassium permanganate index,BOD5 and CODcrfirst increased and then decreased with the change of season,which showed these parameters were higher in autumn than those in spring and winter,while transparency showed the V-shape trend with the highest in spring and the lowest in autumn,and water temperature and TP concentration had no significant differences between water conservancy development zone and CK,the water temperature,pH,TN,NH＋4-N,TP,potassium permanganate index,BOD5 and CODcrin different seasons showed the order：water conservancy development zoneCK with local fluctuation,and the gap was smaller in winter,which indicated that water conservancy development had little effect on water quality in winter;（4）correlation analysis showed that the water temperature and TN concentration had significantly or extremely significantly positive correlation with phytoplankton diversity and pH was significantly negative correlation with phytoplankton diversity,which suggested that water temperature and TN concentration were the main influencing factors on phytoplankton diversity in Ertan reservoir.