广东省大沙河水库轮虫群落结构的时空异质性分析

Temporal and spatial variation of the community structure of rotifers in Dashahe Reservoir,southern China (Guangdong province)

于2010年1月至12月对广东省大沙河水库中的河流区、过渡区和湖泊区进行逐月采样,采集浮游动物并测定水体理化指标,以探讨热带大型富营养化水库轮虫群落结构的时空异质性。在三个采样点,形态学分类共鉴定出25种轮虫,其中19种来自游泳亚目的 6个科,8个属,4种来自簇轮亚目的 1个科,2个属,剩余2种来自胶鞘亚目的 2个科,2个属。数据分析表明:1)大沙河水库轮虫群落结构变化具有明显的季节特征,可分为枯水一期(1—4月),丰水期(5—9月)和枯水二期(10—12月),Indval分析显示不同季节的指示种不同且均不少于三种;2)轮虫群落结构和多样性(Shannon-Hill number)不具有明显的空间异质性,但轮虫多样性和物种数具有显著的季节差异(p=0.004,p=0.007);3)环境变量对轮虫群落结构的解释率为41.269%,水体理化变量解释率31.935%,其中温度解释率16.512%,水库水文变量对轮虫群落结构变化解释率9.334%,水体理化变量对轮虫群落结构有重要的影响。

To investigate the temporal and spatial variation of rotifer community structure in tropical large eutrophication reservoirs,36samples in riverine,transition and lacustrine zones of the Dashahe Reservoir(Guangdong province,China)were gathered monthly in2010;physic-chemical variables and zooplankton community data were also collected.25species were identified.Among them,19species belonged to6families,8genera of Ploima,and4species from1family,2genera of Flosculariacea and the remaining2species belonged to2families,2genera of Collothecacea.The results are as follows.(1)There existed significantly difference among different seasons;the time series samples could be divided into three season clusters:Dry-season-I(Jan-Apr),Flood-season(Mar-Sep),Dry-season-II(Oct-Dec).Indval analysis showed there were no less than three different rotifers seen as indicator species for each season.(2)Spatial variation of the community structure and biodiversity of rotifers(Shannon-Hill number)was not significant,but there was common seasonality of the diversity and richness of rotifers(p=0.004,p=0.007)among the three temporal group.(3)41.269%of all the variation of the community structure of rotifers was explained by environmental variables;physic-chemical variables which included water temperature variable(explained16.512%)explained31.935%of all those variation;and hydrological variables explained9.334%of the rest,which showed the nonnegligible importance of physic-chemical variable of reservoirs to rotifer community structure.