基于着生硅藻指数的梧桐河水生态健康评价

在黑龙江省梧桐河,调查了13个点位的着生硅藻群落结构和水环境特征,应用8种硅藻指数对该河流水生生态系统进行健康评价,并在此基础上应用主成分分析、相关分析、冗余分析、箱型图分析等统计分析方法研究了影响梧桐河着生藻类群落的主要环境因子和8种硅藻指数在梧桐河的适用情况。结果显示:梧桐河存在一定程度的环境污染,优势种以小型异极藻(Gomphonema parvulum)等耐污种为主。8个硅藻指数中,硅藻属指数(Generic Index of Diatom,GI)、澳大利亚河流硅藻生物评价指数(Diatom Index for Australian Rivers,DIAR;Diatom Species Index for Bioassessment of Australian Rivers,DSIAR)评价结果偏差较大,在梧桐河不适用;相似度指数(Jaccard Index,JI)与富营养化硅藻指数(Trophic Diatom Index,TDI)评价结果较为严格,评分明显偏低;硅藻污染耐受指数(Pollution Tolerance Index,PTI)、硅藻生物评价指数(Diatom Bioassessment Index,DBI)和生物硅藻指数(Biological Diatom Index,BDI)在梧桐河流域适用性最好。根据冗余分析(RDA),将梧桐河流域点位分为3组,第一组点位为中-重度污染,主要影响因子为流速和总磷;第二组点位为轻-中度污染,主要影响因子为磷酸盐、氨氮和溶解氧;第三组点位为轻污染-清洁,主要影响因子为p H和电导率。

Health Assessment on Aquatic Ecosystem in Wutong River Using Benthic Diatom Indexes

The community structures of benthic diatoms and water environmental characteristics of 13 sample sites were extensively investigated in Wutong River of Heilongjiang Province, and the aquatic ecosystem health conditions of Wutong River were also evaluated using 8 benthic diatom indexes, i.e. Jaccard Index (JI), Pollution Tolerance Index (PTI), Diatom Bioassessment Index (DBI), Trophic Diatom Index (TDI), Biological Diatom Index (BDI), Generic Index (GI), Diatom Index of Australian Rivers (DIAR) and Diatom Species Index of Australian Rivers (DSIAR). Based on the above-mentioned research, the principal component analysis, Spearman correlation analysis, redundancy analysis and the Boxplot analysis were used to study the applicability of 8 indexes in Wutong River and the main environmental factors influencing the benthic diatom communities structure. The results indicated that the dominant algae species of Wutong River are Gomphonema parvulum and other species with the endurance ability to pollution. Among 8 benthic diatom indexes, the GI, DIAR and DSIAR health assessment results deviation on aquatic ecosystem of Wutong River were large and not applicable to estimate the river aquatic ecosystem conditions, the JI and TDI assessment results were stricter and the obtained scores were too low obviously, and the PTI, DBI and BDI had the best applicability to assess the heath of the aquatic ecosystem conditions in Wutong River. According to RDA, the sampling sties of Wutong River were divided into three groups with different pollution levels. The sampling sites in the first group were in the moderate-heavy pollution level, and the dominant environmental influencing factors were velocity and the total phosphorus; the sites in the second group were in the light-moderate polluted status and the dominant influencing factors were ammonia nitrogen, dissolved oxygen and phosphorus concentration; the sites in the third group were in the light polluted conditions or clean conditions, and the dominant influencing factors were pH and conductivity.