Temporal pattern prevails over spatial variability in phytoplankton communities from a subtropical water supply reservoir

Abstract

Phytoplankton species are dominant components in reservoir ecosystems, yet little is known about their variability and dynamics, especially along the depth continuum. This study examined vertical and horizontal differences in phytoplankton communities in a typical subtropical deep reservoir (i.e. Dongzhen Reservoir) from 2011 to 2012. Phytoplankton communities separated into four groups based on the biomass data, indicating that temporal differences in the community structure were greater than spatial differences. Autumn communities had the highest diversity measured by the ShannonWiener index (2.47±0.07), while summer communities had the lowest diversity (0.46±0.09). Both winter and spring communities were dominated by diatoms (90.4±1.7%), while cyanobacteria dominated in summer communities during our * Corresponding author address: Aquatic EcoHealth Group, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, P. R. China; e-mail: jyang@iue.ac.cn sampling period. In spring and summer, however, the three surface communities characterized by high biomass were most similar to each other, indicating that vertical variation was significantly higher than horizontal differences. Furthermore, Cylindrospermopsis raciborskii accounted for over 96% of the total phytoplankton biomass in the summer surface water. The redundancy analysis (RDA) illustrated that the temporal factor (summer), the spatial factor (depth), and nutrients (nitrite and nitrate nitrogen, ammonium nitrogen, phosphate phosphorus) were significant variables affecting the dynamics of phytoplankton communities. High temperature with stable thermal stratification might have been the cause of C. raciborskii dominance in Dongzhen Reservoir in summer. Regular and longterm monitoring of dominant species is urgently needed for water quality protection and sustainable reservoir management.

Structural Characteristics and Driving Factors of the Planktonic Eukaryotic Community in the Danjiangkou Reservoir, China

“…WT, TN, and Chla were significant factors affecting the community distribution of planktonic eukaryotes in 2018. The results showed that the community structure of planktonic eukaryotes changed significantly with temporal and spatial changes; the temporal changes caused corresponding changes in WT, DO, and other physical and chemical factors in the reservoir area and led to corresponding changes in the community structure and diversity of the planktonic eukaryotes [61]. The change in the central node between the single-factor and two-factor network analysis also illustrates this point.…”

Effects of water stratification and mixing on microbial community structure in a subtropical deep reservoir

“…Several physical, chemical, and biological variables are known to influence the microbial community composition1112. Previous studies showed that the vertical dynamics of the phytoplankton was related to the water column-mixing regime13.…”

Spatial and Temporal Characteristics of Phytoplankton Communities in Drinking Water Source Reservoirs in Shenzhen, China

“…Reservoirs are artificial multi-functional aquatic ecosystems that provide various ecosystem services for social development (e.g., economic, regulation, and cultural values) and represent an important water resource guarantee for social sustainable development [1,2]. China has more reservoirs than any other country, with dams built on almost all major and minor rivers except for Nujiang and Yarlung Zangbo, totaling more than 98,000 [3]. With the growth of the population and the increasing demand for water, the functions of these reservoirs have changed.…”