应用底栖动物完整性指数评价滇池流域入湖河流生态系统健康

Stream ecosystem health assessment of inflow rivers in Lake Dianchi catchment by using Benthic Integrity Biotic Index(B-IBI)

采用底栖动物完整性指数(B-IBI)评价滇池流域入湖河流健康状况.根据滇池流域38个样点(9个参照点,29个干扰点)于2009年丰水期和2010年平水期采得的大型底栖动物数据,对19个生物参数进行分布范围、Spearman相关性和判别能力分析,确定构成滇池流域底栖动物生物完整性的指数为甲壳动物+软体动物分类单元数、集食者%、捕食者%和耐污类群%.用比值法统一量纲,计算各个生物参数的值,并将所得的值相加即得到B-IBI指数值.根据B-IBI指数值的25%分位数确定健康等级标准,并对小于25%分位数的值进行四等分,即得到滇池流域底栖动物完整性的评价标准,B-IBI>1.62为健康,1.03～1.62为亚健康,0.31～1.03为一般,0.10～0.31为较差,<0.10为极差.评价结果表明,滇池流域的38个样点中,16个为健康,5个为亚健康,6个为一般,6个为较差,5个为极差.B-IBI值与硝态氮和水温有较大的负相关关系,与其他理化因子相关性不明显.

Benthic Integrity Biotic Index （B-IBI） was used to evaluate the health of inflow rivers in Lake Dianchi of Yunnan Prov- ince, China. Macroinvertebrate assemblages were collected from 38 sampling sites in Lake Dianchi, including 9 sites that were un- disturbed or less disturbed and 29 sites that were disturbed in wet season of July- Aug. 2009 and dry season of Jan.- Feb. 2010. Tile range of index value distribution, spearman correlation and judgment ability were analyzed for the 19 biological parameters, in- cluding Shannon-Wiener index ; total number of taxa; total density; taxa numbers of Crustacea ＋ Mollusca, Hirudinea, and Mollus- ca taxa; percentage of Crustacea ＋ Mollusca, Hirudinea, Mollusca, Oligochaeta, Limnodrilushoffmeisteri, Chironomidae, Oli- gochaeta/Hirudinea, Gatherers, Predator, Omnivore, and Scrapers; percentage of tolerant taxa; and Goodnight index. Ratio sco- ring method for B-IBI index was used to get a uniform score. By using the each 20 percentiles of B-IBI as a criteria to evaluate the aquatic ecosystem health, the results showed that, health criteria when B-IBI〉 1.62, sub-health when 1.03 - 1.62, good-fair when 0.31 - 1.03, fair when 0.10 -0.31, and poor when B-IBI 〈0.10. The B-IBI index was positive correlation to NO3- -N and water temperature, but not significantly correlation to other factors.