Urbanization often exerts multiple effects on aquatic and terrestrial organisms,including changes in biodiversity,species composition and ecosystem functions.However,the im-pacts of urbanization on river phytoplankton in subtropical urbanizing watersheds remain largely unknown.Here,we explored the effects of urbanization on phytoplankton commu-nity structure (i.e.,biomass,community composition and diversity) and function (i.e.,re-source use efficiency) in a subtropical river at watershed scale in southeast China over 6 years.A total of 318 phytoplankton species belonging into 120 genera and 7 phyla were identified from 108 samples.Bacillariophyta biomass showed an increasing trend with in-creasing urbanization level.The phytoplankton community shifted from Chlorophyta dom-inance in rural upstream waters to Bacillariophyta dominance in urbanized downstream waters.Furthermore,phytoplankton diversity and resource use efficiency (RUE =phyto-plankton biomass/total phosphorus) were significantly decreased with increasing urbaniza-tion level from upstream to downstream.Phytoplankton RUE exhibited a significant positive correlation with species richness,but a negative correlation with phytoplankton evenness.The variation in environmental factors (turbidity,total nitrogen,NH4+-N,total phosphorus,PO43-P and percentage urbanized area) was significantly correlated with phytoplankton di-versity and RUE.Overall,our results revealed the influence of urbanization on phytoplank-ton community structure and ecosystem function was due to its altering the environmen-tal conditions.Therefore,human-driven urbanization may play crucial roles in shaping the structure and function of phytoplankton communities in subtropical rivers,and the mech-anism of this process can provide important information for freshwater sustainable uses,watershed management and conservation.

Yigang Yang;Huihuang Chen;Mamun Abdullah Al;Jean Claude Ndayishimiye;Jun R Yang;Alain Isabwe;Anqi Luo;Jun Yang

Aquatic EcoHealth Group,Fujian Key Laboratory of Watershed Ecology,Key Laboratory of Urban Environment and Health,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,China;University of Chinese Academy of Sciences,Beijing 100049,China;Engineering Research Center of Ecology and Agricultural Use of Wetland (Ministry of Education),College of Agriculture,Yangtze University,Jingzhou 434025,China

环境科学学报（英文版）

[1]Yigang Yang;Huihuang Chen;Mamun Abdullah Al;Jean Claude Ndayishimiye;Jun R Yang;Alain Isabwe;Anqi Luo;Jun Yang-.Urbanization reduces resource use efficiency of phytoplankton community by altering the environment and decreasing biodiversity)[J].环境科学学报（英文版）,2022(02):140-151

inance,phytoplank

Urbanization,reduces,resource,efficiency,phytoplankton,community,by,altering,decreasing,biodiversity,often,exerts,multiple,effects,aquatic,terrestrial,organisms,including,changes,species,composition,ecosystem,functions,However,pacts,urbanization,subtropical,urbanizing,watersheds,remain,largely,unknown,Here,explored,structure,biomass,scale,southeast,China,over,years,total,belonging,into,genera,phyla,were,identified,from,samples,Bacillariophyta,showed,increasing,trend,level,shifted,Chlorophyta,rural,upstream,dominance,urbanized,downstream,Furthermore,RUE,phosphorus,significantly,decreased,Phytoplankton,exhibited,positive,correlation,richness,but,negative,evenness,variation,environmental,factors,turbidity,nitrogen,NH4+,PO43,percentage,area,was,correlated,Overall,results,revealed,influence,due,its,conditions,Therefore,human,driven,may,play,crucial,roles,shaping,communities,rivers,mech,this,process,provide,important,information,freshwater,sustainable,uses,management,conservation

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