The characteristics of phytoplankton community structure and its relationship with environmental factors during extreme drought of a large-scale reservoir——Take Xinfengjiang Reservoir for example
In 2021,the Xinfengjiang reservoir basin experienced the extreme drought in 60 years.To understand the characteristics of the phytoplankton community structure and its relationship with environmental factors,an investigation was carried out monthly from 2020.1 to 2021.12 in Xinfengjiang Reservoir,a large-scale oligotrophic reservoir in southem China.The results showed that the water quality indexes of Xinfengjiang Reservoir basically met the'Surface Water Environmental Quality Standard'(GB3838-2002)Ⅰ during both periods of normal and extreme drought.The values of TLI ranged from 14 to 28 in 2021,increasing about 19.1％compared to 2020,which indicated that the reservoir wasin poor nutrition state.A total of 201 phytoplankton species were identified belonging to 8 phyla and 90 genera in 2020,as well as 191 phytoplankton species were identified in 2021 belonging to 8 phyla and 86 genera.Among these species,Chlorophyta,Cyanophyta,Bacillariophyta,Euglenophyta and Pyrroptata were main compositions of the total phytoplankton species.The structure of phytoplankton community was Chlorella-Cyanophyta form in 2020,as well as Chlorella-Diatom form in 2021.The average abundance of phytoplankton were 1.38×106cells/L and 0.41×106cells/L in 2020 and 2021,respectively.As for the composition of phytoplankton abundance,the former drought was significantly different from the period of drought,which attributed that decreasing nutrient input restricted algal proliferation activities.Correlation and canonical correspondence analysis showed that water temperature,ammonia nitrogen,dissolved oxygen,total phosphorus,transparency were the key factors controlling phytoplankton community structure change in former drought,and those of water,temperature,ammonia nitrogen、conductivity、pH value、total nitrogen、Permanganate index、transparency for phytoplankton community structure during drought period in Xinfengjiang Reservoir.
Xinfengjiang reservoirextreme droughtphytoplanktontemporal and spatioal-temporal variationenvironmental factor
万方数据
