Distribution and evaluation of diatom community in Hejiang River, a branch of Xijiang River, Pearl River basin

Abstract

综合运用TWINSPAN数量分类和DCA排序方法评估了贺江流域硅藻群落,结合硅藻生物指数(IBD)、硅藻属指数(IDG)、硅藻营养化指数(TDI)和特定污染敏感指数(IPS)对其结果进行进一步验证.结果显示,TWINSPAN将贺江流域的38个样点分为4组,且群落Ⅰ到群落Ⅳ其生境质量逐渐变得单一,人为干扰程度逐渐加大;划分的四组群落在DCA排序图上有明显的界限,依据Van Dam硅藻生态指示意义,水环境污染程度从群落Ⅰ到群落Ⅳ逐渐加剧,有争议的样点7、8和24在DCA排序图上也倾向于群落Ⅲ.4种硅藻指数都是显著相关的,但IBD、IPS、IDG在硅藻群落的箱型图中明显呈现出合理的趋势.以上研究表明,划分的硅藻群落较好地反映了贺江流域的生态质量,IBD、IPS、IDG适合于贺江流域生物监测与评价.;The diatom communities of Hejiang River, a branch of Xijiang River, Pearl River basin were evaulated by means of two-way indicator species analysis and detrended correspondence analysis. The diatom indexes of Generic Diatom Index(IDG), Biological diatom index(IBD), Specific Pollution sensitivity Index(IPS) and Trophic Diatom Index(TDI) were then further used to validate the conclusion. According to TWINSPAN, the 38 sampling sites of Hejiang River were classified into 4 types, the quality of ecological habitat and human disturbance were getting worse and worse from community Ⅰ to community Ⅳ; the obvious boundaries of four communities existed on DCA ordination diagram, the ecological value of Van Dam showed that water environmental pollution gradually increased from Ⅰ to Ⅳ, the controversial samples of 7, 8 and 24 tended to community Ⅲ on DCA ordination diagram. The results indicated that the divided diatom communities can better reflect the ecological quality, in addition, IBD, IPS, IDG can be applied for monitoring and evaluating rivers in Hejiang River.