Differences in phytoplankton dynamics and community structure between a wet year and dry year in the Zhoucun Reservoir

Abstract

Rainfall-induced nutrient fluctuations in surface water affect phytoplankton communities and cause algal blooms. To examine this influence in the Zhoucun Reservoir, China, field surveys were performed weekly or biweekly from February 2013 (a wet year) to December 2014 (a dry year). Physical conditions, nutrient levels, and phytoplankton functional groups were investigated during monitoring. Nutrient levels increased in the summer of 2013 (TN: 0.85À2.66 mg/L; TP: 0.037À0.138 mg/L), while nitrogen deficiency occurred in the summer of 2014 (TN: 0.38À0.73 mg/L, TP: 0.044À0.079 mg/L). A cyanobacteria bloom that appeared in the summer of 2013 had the dominant phytoplankton functional groups M and Tc. In the summer of 2014, algal cell density and biomass were much lower than those during the corresponding period in 2013, and the co-dominant phytoplankton groups were F, L 0 , Tc, and S2. Non-N-fixing cyanobacteria were not abundant in summer 2013 probably because of the low ratio of NO 3 ¡ to NH 4 C , although nitrogen was also deficient. In contrast to these summer trends, little difference was noted between phytoplankton dynamics and community structure in the two winters and two springs, regardless of nutrient conditions. Redundancy analysis indicated that rainfall-induced nitrogen fluctuations were the primary factor causing phytoplankton dynamics to differ between the wet and dry year. The effects of water temperature, stratification, and light on the phytoplankton community were independent of nutrient fluctuations. This study shows that rainfall fluctuations change summer nutrient conditions and that cyanobacteria blooms are likely to occur in wet years in the Zhoucun Reservoir.

Driving Factors and Dynamics of Phytoplankton Community and Functional Groups in an Estuary Reservoir in the Yangtze River, China

“…Typical patterns of phytoplankton succession were found in temperate eutrophic lakes, such as the PEG Model [56], a model believed that the key factor controlling phytoplankton dynamics of community and succession in lakes and reservoirs is thermal stratification and developed for phytoplankton seasonal succession study in a comparative way. In current study results suggested two biomass peaks (Figure 2f) when denoted as total Chl a: one peak in summer, with taxa belonging to F and M, and another peak during autumn with colonial taxa, belonging to such functional groups as Y and P. Our results of phytoplankton succession pattern were similar with other studies [18,22,57] conducted in Chinese reservoir but different from the PEG model, in which phytoplankton biomass reached two peaks in spring and summer, respectively.…”

Dynamics of Bacterial and Fungal Communities during the Outbreak and Decline of an Algal Bloom in a Drinking Water Reservoir

“…The drainage area of the reservoir is 121 km 2 , and the total storage capacity is about 84 million m 3 . The maximum depth is 18 m, and the average depth is 13 m. Due to higher nitrogen and phosphorus concentrations, algal blooms mainly occur during summer seasons (from July to September), and more severe Microcystis blooms have occurred in recent years [ 15 , 16 ].…”

The Variation Characteristic of Sulfides and VOSc in a Source Water Reservoir and Its Control Using a Water-Lifting Aerator

“…In its drainage area, there are only a few small poultry farms; no coking, paper milling, leather processing, or other industrial wastewater is discharged into the reservoir. The reservoir has been used for cage fish farming for more than 30 years, which results in its eutrophication in recent years [ 28 ]. From April to November 2014, hypoxia due to stratification was one of the environmental problems in the bottom water (from 6 m to the sediments surface) of the Zhoucun Reservoir ( Figure 2 ).…”