基于浮游细菌生物完整性指数的城市河流健康评价：以深圳河流域为例

河流中的细菌是生态系统中物质循环的重要参与者，能反映河流健康状况，其群落生物指标具有评估城市河流生态状况的潜力。通过调查深圳河流域内深圳河、布吉河和福田河3条河流中的浮游细菌群落，构建了生物完整性指数 (Ba-IBI) ，评估了该流域的健康状况。基于河水浮游细菌的Illumina高通量测序结果，通过差异性检验、箱线图筛选和相关性分析方法从163个候选指标中筛选出变形菌门、放线菌门和微丝藻菌目相对丰度及门水平Simpson多样性指数作为核心指标，构建Ba-IBI评价体系。结果表明，深圳河流域内的20个位点中处于健康状态、亚健康状态、一般状态和较差状态的位点数分别为7个、4个、5个和4个。其中，深圳河处于一般和较差状态的点位比例高达85.7%；健康状况从上游到下游逐渐恶化；整体健康状况较差。布吉河和福田河健康状况相对较好，处于亚健康状态。各采样点Ba-IBI得分与水质状况的相关性较高 (R=0.77，P<0.01) ，表明Ba-IBI能有效评价城市河流的健康状况。本研究结果可为深圳市河流的修复和管理工作提供参考。

Urban river health assessment based on biotic integrity bacterioplankton-index of biotic integrity : A case study of Shenzhen River Basin

Anthropic impacts on urban rivers induced the macrobiotic species disappearance and the biodiversity losses, which reduced the accuracy of bioassessment．Bacteria are important decomposers in the ecosystem material cycle and have the potential to indicate the health status of rivers. The development of biological indicators based on bacterial community for assessing aquatic ecological status is urgently needed. In this study, bacterioplankton-index of biotic integrity (Ba-IBI) was constructed to evaluate the status of three urban rivers in Shenzhen River Basin. Based on the Illumina high-throughput sequencing results of planktonic bacteria, the core indicators were identified by difference examination, boxplot screening and correlation analysis. Among the 163 candidate indicators, the relative abundance of Proteobacteria, Actinomycetes, Microfilariae and Simpson index at the phylum level were regarded as the core indicators to develop the Ba-IBI. The results showed that 7, 4, 5 and 4 of the 20 sites in the Shenzhen River basin were in healthy state, sub-healthy state, general state and poor state, respectively. The Shenzhen River was in poor states, with 85.7% of the points in the general or poor states, and the health status gradually deteriorated from the upstream to the downstream. Buji River and Futian River were in sub-health states. There was a high correlation between Ba-IBI score and water quality (R=0.77, P<0.01) suggesting that Ba-IBI could effectively evaluate the health states of urban rivers. This study can provide a reference for the restoration and management of rivers in Shenzhen.