Urbanization reduces resource use efficiency of phytoplankton community by altering the environment and decreasing biodiversity

• 作者: Yigang Yang Huihuang Chen Mamun Abdullah Al Jean Claude Ndayishimiye Jun R Yang Alain Isabwe Anqi Luo Jun Yang
• 来源期刊: 环境科学学报（英文版）
• 年，卷（期）: 2022,（2）
• 所属期刊栏目: Regular articles
• 页码范围: 140-151
• 页数: 12页
• 语种: 英文

摘要

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.