基于底栖动物生物完整性指数(B-IBI)对呼兰河口湿地生态系统健康评价

Health Assessment of Wetland Ecosystem in Hulan Estuary Wetlands Based on Benthic Macroinvertebrates Integrity Index

底栖动物生物完整性指数(B-IBI)是水生态系统健康评价常用指标之一。根据呼兰河口湿地以及周边水域30个样点(9个参照点和21个受损点),通过对候选生物参数判别能力分析、敏感性分析、Pearson相关性分析,决定构成B-IBI值的参数共有6个,即:总分类单元数、EPT (E蜉蝣目、F襀翅目、T毛翅目)分类单元数、蜉蝣目%、直接集食者%、耐污类群%和生物指数BI。利用比值法和三分法计算得到B-IBI值,建立了评价水体健康的5级标准。比值法为:>3.56健康,2.67~3.59亚健康,1.78~2.66一般,0.89~1.77差,26健康,20~26亚健康,13~19一般,7~12差,<6极差。利用上述标准对呼兰河口湿地水生态系统的健康状况进行评价,结果表明,三分法和比值法得到的结果基本一致。本研究选择的参照点评价结果为健康,呼兰河口湿地样点处于一般到亚健康的状态。

Benthic Index of Biotic Integrity(B-IBI) index is one of the commonly used indexes for aquatic ecosystem health evaluation. Macroinvertebrate assemblages were collected from 30 sites(among them, 9 were unimpaired or minimally impaired sites and 21 were impaired sites) in Hulan Estury wetlands. Through the discriminant power analysis by candidate biological parameters of, sensitivity analysis and Pearson’s correlation analysis, as the result, the benthic index of biotic integrity(B-IBI) was composed by six metrics: Total number of taxa, EPT(Ephemeropterodae, Plecoptera, Trichoptera) taxa, Ephemera%, Clingers%, Gatherers-collectors%, Intolerant taxa% and Biotic Index(BI). The establishment of health assessment 5 lever criteria for aquatic ecosystem uses Ratio Method and Three Points Method. The former: > 3.56, health; 2.67-3.59, sub-health; 1.78-2.66, good-fair; 0.89-1.77, fair; < 0.88 poor; the latter: > health; 20-26, sub-health, 13-19, good-fair; 7-12, fair; < 6 poor. The correlation between two scoring methods and four scoring methods was 0.891. Therefore, the two methods were suitable for water ecosystem health assessment in the Hulan estuary wetland and the surrounding waters. The water ecosystem health was assessed based on the establishment standard above-mentioned in the Hulan estuary wetland and the surrounding waters. The result indicated that there was no difference in the assessment result between Ratio Method and Three Points Method. All references were healthy. Hulan Estuary Wetland was in the condition from good fair to sub-heath.