title: [Stream health assessment using a benthic-index of biotic integrity in Xitiaoxi Stream, Zhejiang Province, China].
abstract: Stream macro-invertebrate assemblages were collected from 64 stream sites in Xitiaoxi Stream, Anji County, Zhejiang Province, China. Thirty-six candidate metrics were evaluated stepwise by distributing range analysis, discriminatory power analysis, and Pearson's correlation analysis. The B-IBI was composed of seven metrics: total taxa, EPT taxa, Coleoptera %, three dominant taxa, Hydropsychidae (Trichoptera) %, filterers %, and Biotic Index (BI). The ratio scoring method was used to transform the value of each metric into a uniform score. A variability coefficient method and an entropy method were used to calculate the weight value of each metric of the B-IBI. The measurement accuracy of the health criteria for the B-IBI derived from all sample data was better than that from only reference data. The entropy method had a higher accuracy (92.9%) than the sum total score method (85.7%) and the variability coefficient method (78.5%) in discriminating stressed and reference sites. The B-IBI health criteria for Xitiaoxi Stream were: B-IBI > 0.69 = healthy, 0.52 - 0.68 = sub-healthy, 0.35-0.51 = good-fair, 0.18-0.34 = fair, B-IBI < 0.17 = poor. The Pearson's correlation analysis between B-IBI and chemical-physical variables showed that the B-IBI strongly corresponded with the habitat quality index (r = 0.62, p < 0.01), water temperature (r = -0.64, p < 0.01), and altitude (r = 0.64, p < 0.01). Our results suggest that the B-IBI is a good indicator in stream health assessment and should be used in water resource management in China.
authors.affiliation: Laboratory of Aquatic Insects and Stream Ecology, Department of Entomology, Nanjing Agricultural University, Nanjing 210095, China. liqiang401@tom.com
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Lian-fang
authors.initials: LF
authors.lastname: Yang
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.forename: Bei-xin
authors.initials: BX
authors.lastname: Wang
mesh_terms: D000818:Animals; D002681:China; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods* / Q000706:statistics & numerical data; D005618:Fresh Water / Q000032:analysis*; D007448:Invertebrates / Q000254:growth & development*; D011157:Population Dynamics; D012016:Reference Values; D045483:Rivers; D014873:Water Pollutants / Q000032:analysis*; D014881:Water Supply / Q000032:analysis
chemical_list: D014873:Water Pollutants