南方某水库轮虫群落特征及其对环境因子的响应

Response of rotifer community characteristics to environmental factors in a reservoir,Southern China

于2006年8月至2007年8月,对广东省某水库4个站点轮虫群落的周年变化进行了调查分析,同时测定了浑浊度、叶绿素、总氮、总磷等理化因子。调查期间,共记录轮虫41种,以臂尾轮属和异尾轮属种类居多,全年以广布多肢轮虫(Polyarthravulgaris)和尖尾疣毛轮虫(Synchaetastylata)为主要优势种;轮虫丰度范围为6-1966ind./L,以库心和大坝处的轮虫丰度较高,高峰期出现在夏秋季。相关分析显示叶绿素浓度对轮虫群落有重要影响。典范对应分析(CCA)表明,采样站点具有明显的空间异质性。CCA分析还表明浑浊度和透明度是影响轮虫空间分布的重要因子,水温和叶绿素浓度是影响轮虫群落结构季节变化的主要因子。CCA排序可将轮虫分为3个类群,优势种广布多肢轮虫位于CCA坐标轴的原点附近,表明其所受环境因子影响较小。根据相关加权营养状态指数(TLI),该水库处于中营养型。

A survey of rotifers was carried out at four sites in a reservoir in Guangdong Province,from August 2006 to August 2007.Turbidity,Chlorophyll a（Chl a）,Total Nitrogen（TN）,Total Phosphorus（TP）were measured.Forty-one species of rotifers were recorded during the survey.The dominant species were Polyarthra vulgaris and Synchaeta stylata.The rotifer densities ranged from 6 to 1966 ind./L.There was a significant positive correlation between rotifer densities and chlorophyll a concentrations.Canonical correspondence analysis（CCA）was applied to explore the relationship between rotifer species and environmental parameters.The result of CCA showed that turbidity,transparency,temperature and chlorophyll a concentration were the most important factors regulating the composition and temporal-spatial dynamics of the rotifers community.Trophic state indexes（TLI）based on data of TN,TP,CODMN and chlorophyll a concentration ranged from 30 to 40,indicated the reservoir was in the meso-trophic level.