基于底质细菌IBI的长江南京段生态健康评价

Ecological health assessment on Nanjing Section of Changjiang River based on benthic bacteria-index of biological integrity

针对长江南京段生态健康问题,于2019年平水期和丰水期在长江南京段干流的10个断面和21条入江支流进行采样,利用高通量测序的方法研究底质细菌群落的结构组成,构建了底质细菌群落完整性指数(benthic bacteria-index of biological integrity,B-IBI)。结果表明:平水期长江南京段的生态健康要优于丰水期,长江干流断面要优于支流断面;TN、NH_(3)-N、NO_(3)^(-)、TOC与B-IBI呈显著负相关,Shannon指数、Margalef指数、Evenness指数与B-IBI呈显著正相关;研究建立的评价体系对于长江水质状况和生境有较好的指示作用;硬质护坡或河底对于入江支流细菌群落的多样性有负面影响,建议在确保防汛的基础上加强河道的生态修复。

To address ecological health on Nanjing Section of the Changjiang River,we sampled at 10 mainstream sections and 21 tributaries in Nanjing Section in the dry and wet seasons of 2019.High-throughput sequencing was used to analyze the structural composition of benthic bacterial communities,by which the benthic bacteria-index of biological integrity(B-IBI) was established.The results showed that the ecological health on Nanjing Section of Changjiang River was better in the normal water season than that in the wet season,and it was superior in the mainstream than in the tributaries.Total nitrogen,ammonium,nitrate,and total organic carbon were negatively correlated with the B-IBI,while the Shannon,Margalef,and Evenness indices were positively correlated.The established evaluation system effectively indicated the water quality and habitat conditions of the Changjiang River.Hard revetments or riverbeds negatively affected bacterial community diversity in tributaries.It is suggested to strengthen the ecological restoration of rivers on the basis of ensuring flood prevention.