Hydrodynamics Regulate Longitudinal Plankton Community Structure in an Alpine Cascade Reservoir System

Abstract

Previous studies report significant changes on biotic communities caused by cascade reservoir construction. However, factors regulating the spatial–temporal plankton patterns in alpine cascade reservoir systems have not been fully explored. The current study explored effects of environmental factors on the longitudinal plankton patterns, through a 5-year-long study on the environmental factors and communities of phytoplankton and zooplankton in an alpine cascade reservoir system located upstream of Yellow River region. The findings showed that phytoplankton and zooplankton species numbers in the studied cascade reservoir system were mainly regulated by the hydrological regime, whereas nutrient conditions did not significantly affect the number of species. Abundance and biovolume of phytoplankton in cascade reservoirs were modulated by the hydrological regime and nutrient conditions. The drainage rate, N:P ratio, and sediment content in cascade reservoirs were negatively correlated with abundance and biovolume of phytoplankton. Abundance and biovolume of zooplankton were not significantly correlated with the hydrological regime but showed a strong positive correlation with nutrient conditions in cascade reservoirs. Shannon–Wiener index (H’) and the Pielou index (J) of phytoplankton were mainly regulated by the hydrological regime factors, such as drainage rate and sediment content in cascade reservoirs. However, temperature and nutrient conditions were the main factors that regulated the Shannon–Wiener index (H’) and the Pielou index (J) of zooplankton. Species number, abundance, and biovolume of phytoplankton showed a significant positive correlation with those of zooplankton. Hydrodynamics and nutrient conditions contributed differently in regulating community structure of phytoplankton or zooplankton. These findings provide an understanding of factors that modulate longitudinal plankton community patterns in cascade reservoir systems.

Assessment of the trophic state of the Soła River dam cascade, Polish Carpathians: a comparison of the methodology

“…It is exposed to the mixing of water and bottom sediments during floods, which causes high turbidity in the water under such situations. On the other hand, the Tresna Reservoir has a purifying effect on the water of the Soła River—the purifying effect of dam reservoirs, especially cascade systems, has been described in publications from various countries [e.g., 23 , 50 ]. Stachowicz and Czernoch 31 found that the waters of the Porąbka and Czaniec reservoirs have more favorable physical and chemical parameters than the water of the Tresna Reservoir.…”

“…Fragilaria crotonensis, Aulacoseira granulata, Nitzschia acicularis, Asterionella formosa, Diatoma vulgaris . These taxa have been observed in eutrophic reservoirs in various parts of the world—Finnish lakes 60 , Czech reservoirs 73 and Chinese 23 , as well as in Polish oxbow lakes rich in biogens 74 . Species with oligotrophic (e.g., Encyonema minutum ) and mesotrophic preferences (e.g., Oocystis borgei ) also appeared in small numbers.…”

Seasonal Dynamics and Environmental Drivers of Phytoplankton Composition in a Tropical Dam Over 5 Years in Chiang Mai, Thailand

“…Algae respond to these parameters, such as Anabaena and Cosmodladium related to SRP, Asterococcus and Chroococcus responding to BOD and Ceratium responding to turbidity. Previous studies report that these algae well-adapted groups and can tolerate environmental factor deficiencies more successfully than less adapted species, and the abundance of algae represents eutrophic water [35,36]. Therefore, the presence of this group is not conducive to good water quality in the dam, leading to a deterioration in water quality.…”