应用浮游植物生物完整性指数评价长江上游河流健康

2013年11月-2014年6月对长江上游宜宾至江津段五个断面的浮游植物进行了四次调查,共鉴定出浮游植物6门38属95种。对13个备选指标进行分布范围、判别能力及Pearson相关性分析,构建了适合长江上游的浮游植物生物完整性指数(P-IBI)指标体系,即香农多样性指数、Margalef丰富度指数、Pielou均匀度指数、浮游植物密度、硅藻密度百分比等参数指标。采用3分制法、4分制法和比值法分别对生物指标计分,评价结果显示:高庄桥、羊石处于"健康"状态;白沙处于"亚健康"状态;而江安、德感处于"亚健康"向"一般"过渡状态。综合来看,三种评价方法所反映各样点的健康状况基本一致,只是4分制法和比值法在划分评价等级上更细致,评价结果更精确。Pearson相关性分析显示:TN、pH与P-IBI值呈显著负相关(P0.05)。

Ecological health assessment of the upper reaches of the Yangtze River,based on biotic integrity index of phytoplankton

In the present study, phytoplankton samples were collected from the upper reaches of the Yangtze River during four consecutive seasons, from November 2013 to November 2014.The results showed that there were 95 phytoplankton species belonging to 6 phyla and 38 genera found in the investigating region.And based on the distributing range,discriminatory power and Pearson's correlation analysis of the 13 candidate indexes, five metrics, including Shannon-Wiener index, Margalef index, Pielou index, density of phytoplankton, percentage of bacillariophyta were selected to establish biotic integrity index of phytoplankton (P-IBI) evaluation system.Three score system, four score system and ratio score system were used to get metrics into a uniform score for all the sampling points, and the results showed that Gao Zhuangqiao and Yang Shi were in the state of health, Bai Sha in sub-health, and Jiang An and De Gan in the sub-health to good-fair transitional phase.On the whole, the health state of each sampling sites reflected by the three scoring methods almost the same.However, four score system and ratio score system were more meticulous on the grade classification and evaluation, thus the evaluation results of four score system and ratio score system were more accurate.The Pearson′s correlation analysis showed that the P-IBI was significantly negative correlated with TN and pH (P<0.05).