scholarly journals Seasonal and inter-annual community structure characteristics of zooplankton driven by water environment factors in a sub-lake of Lake Poyang, China

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7590 ◽  
Author(s):  
Beijuan Hu ◽  
Xuren Hu ◽  
Xue Nie ◽  
Xiaoke Zhang ◽  
Naicheng Wu ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Water Level ◽  
Dominant Species ◽  
High Water ◽  
Wet Season ◽  
High Water Level ◽  
Lake Poyang ◽  
Density And Biomass ◽  
Zooplankton Communities

Background Sub-lakes are important for the maintenance of the ecosystem integrity of Lake Poyang, and zooplankton play an important role in its substance and energy flow. Methods A seasonal investigation of zooplankton was conducted in spring (April), summer (July), autumn (October) and winter (January of the following year) from 2012 to 2016 in a sub-lake of Lake Poyang. The aim of the present study was to understand the seasonal dynamics and interannual variation of zooplankton communities and their relationship to environmental factors. Results A total of 115 species were identified in all samples in the four years, which comprised of 87 Rotifera, 13 Cladocera and 15 Copepoda. Rotifera was the dominant group in terms of quantity, and its species richness and abundance were significantly higher when compared to Cladocera and Copepoda (P < 0.05), while Cladocera dominated in terms of biomass. The species richness of Rotifera exhibited a significant seasonal difference (P < 0.05). Both the density and biomass of zooplankton revealed significant seasonal differences (P < 0.05). In general, the density and biomass of zooplankton were higher in summer and autumn, when compared to winter and spring. Biodiversity indices were dramatically lower in spring than in the other seasons. The non-metric multidimensional scaling (NMDS) analysis suggested that these zooplankton communities can be divided into three groups: spring community, summer-autumn community, and winter community. The seasonal succession of zooplankton communities did not have interannual reproducibility. In high water level years, the dominant species of zooplankton (Cladocerans and Copepods) in the wet season had a lower density, and the result in low water level years was exactly the opposite. The redundancy analysis revealed that water temperature (WT), conductivity, pH and dissolved oxygen (DO) had significant effects on the zooplankton community. Conclusions The community structure of zooplankton has a significant seasonal pattern, but has no interannual repeatability. In high water level years, the dominant species of zooplankton (Cladocerans and Copepods) in the wet season had a lower density, and the result in low water level years was exactly the opposite. The density, biomass and diversity indices of zooplankton were significantly different in different seasons. The present study was helpful in the further understanding of the ecosystem stability of lakes connected with rivers, providing scientific guidance for the protection of lake wetlands.

scholarly journals Seasonal and inter-annual community structure characteristics of zooplankton driven by water environment factors during different hydrological years in a sub-lake of Lake Poyang, China

2019 ◽  
Author(s):  
Beijuan Hu ◽  
Xuren Hu ◽  
Xue Nie ◽  
Xiaoke Zhang ◽  
Naicheng Wu ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Water Level ◽  
Seasonal Succession ◽  
Zooplankton Community ◽  
Water Level Fluctuations ◽  
Zooplankton Community Structure ◽  
Lake Poyang ◽  
Density And Biomass ◽  
Zooplankton Communities

Shallow lakes are important for the maintenance of Lake Poyang ecosystem integrity, and zooplankton play an important role in its substance and energy flow. We investigated zooplankton in spring (April), summer (July), autumn (October) and winter (January of the following year) from 2012 to 2016 in a sub-lake of Lake Poyang with seasonal water level fluctuations. The study aims to understand their seasonal dynamics and interannual variation of zooplankton community in relation to environmental variables. A total of 115 species were identified in all samples of the 4 years, comprising 87 Rotifera, 13 Cladocera and 15 Copepoda. Rotifera was the dominant group in quantity and its species richness and abundance were significantly higher than Cladocera and Copepoda (P<0.05, by ANOVA), while Cladocera dominated in biomass. Species richness of Rotifera showed a significant seasonal difference (P<0.05 by ANOVA). The clear decline of zooplankton species richness in spring was mainly due to the dramatic decrease of Rotifera species. Furthermore, both density and biomass of zooplankton showed significant seasonal differences (P<0.05). Generally, the density and biomass of zooplankton were higher in summer and autumn than in winter and spring. Biodiversity indices e.g., Shannon-Wiener index and evenness were dramatically lower in spring than in other seasons. Non-metric multidimensional scaling (NMDS) analysis suggested that the zooplankton communities can be divided into three groups: spring community, summer–autumn community and winter community associated with distinct indicator species. The results of species richness and community analysis showed that the seasonal succession of zooplankton communities did not have interannual reproducibility. Redundancy analysis revealed that water temperature (WT), conductivity, pH and dissolved oxygen (DO) had significant effects on the zooplankton community. In addition, water level fluctuations, disturbance by wintering waterbirds and artificial water level control during dry season have potential effects on zooplankton community structure too. This study is helpful to further understand the ecosystem stability of lake connected with rivers and provide scientific guidance for protection of lake wetlands.

scholarly journals Seasonal and inter-annual community structure characteristics of zooplankton driven by water environment factors during different hydrological years in a sub-lake of Lake Poyang, China

2019 ◽  
Author(s):  
Beijuan Hu ◽  
Xuren Hu ◽  
Xue Nie ◽  
Xiaoke Zhang ◽  
Naicheng Wu ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Water Level ◽  
Seasonal Succession ◽  
Zooplankton Community ◽  
Water Level Fluctuations ◽  
Zooplankton Community Structure ◽  
Lake Poyang ◽  
Density And Biomass ◽  
Zooplankton Communities

Shallow lakes are important for the maintenance of Lake Poyang ecosystem integrity, and zooplankton play an important role in its substance and energy flow. We investigated zooplankton in spring (April), summer (July), autumn (October) and winter (January of the following year) from 2012 to 2016 in a sub-lake of Lake Poyang with seasonal water level fluctuations. The study aims to understand their seasonal dynamics and interannual variation of zooplankton community in relation to environmental variables. A total of 115 species were identified in all samples of the 4 years, comprising 87 Rotifera, 13 Cladocera and 15 Copepoda. Rotifera was the dominant group in quantity and its species richness and abundance were significantly higher than Cladocera and Copepoda (P<0.05, by ANOVA), while Cladocera dominated in biomass. Species richness of Rotifera showed a significant seasonal difference (P<0.05 by ANOVA). The clear decline of zooplankton species richness in spring was mainly due to the dramatic decrease of Rotifera species. Furthermore, both density and biomass of zooplankton showed significant seasonal differences (P<0.05). Generally, the density and biomass of zooplankton were higher in summer and autumn than in winter and spring. Biodiversity indices e.g., Shannon-Wiener index and evenness were dramatically lower in spring than in other seasons. Non-metric multidimensional scaling (NMDS) analysis suggested that the zooplankton communities can be divided into three groups: spring community, summer–autumn community and winter community associated with distinct indicator species. The results of species richness and community analysis showed that the seasonal succession of zooplankton communities did not have interannual reproducibility. Redundancy analysis revealed that water temperature (WT), conductivity, pH and dissolved oxygen (DO) had significant effects on the zooplankton community. In addition, water level fluctuations, disturbance by wintering waterbirds and artificial water level control during dry season have potential effects on zooplankton community structure too. This study is helpful to further understand the ecosystem stability of lake connected with rivers and provide scientific guidance for protection of lake wetlands.

Numerical Simulation of Engineering Wave for Zhongzui Bay

2007 ◽  
Author(s):  
Xiejun Shu ◽  
Senhui Jiang ◽  
Ruijie Li
Keyword(s):  
Numerical Simulation ◽  
Water Level ◽  
Simulation Method ◽  
High Water ◽  
Wave Transformation ◽  
Return Periods ◽  
Engineering Construction ◽  
Wave Refraction ◽  
High Water Level ◽  
Mild Slope Equation

For providing a better shelter condition, it is necessary to build a breakwater in Zhongzui Bay. In order to know whether mooring area meets the requirement after engineering construction and compare the mooring area between solid breakwater and permeable breakwater, a numerical simulation method is used in the sheltering harbor of Zhongzui Bay. The used Mild-slope equation which describes wave refraction, diffraction and reflection, considers the steep slope bottom and effect of energy dissipation. It has been validated to fit for simulating wave transformation in the coastal zone. Under extreme high water level and design high water level, wave fields in the calculation area of three wave types in three different return periods are simulated by using this method respectively. In addition, wave height in front of breakwater can be provided. Then the wave parameters and the mooring area of two occasions, with and without breakwater, are gained in calculation area. Based on these results, some conclusions are presented in the end.

scholarly journals The influence of Three Gorges Reservoir high water level on the rainfall runoff

2018 ◽  
Vol 246 ◽  
pp. 01007
Author(s):  
Biqiong Wu ◽  
Wei Zheng ◽  
Xinkai Ren ◽  
Tao Xu ◽  
Xiao Guo
Keyword(s):  
Water Level ◽  
Three Gorges Reservoir ◽  
Reference Value ◽  
High Water ◽  
Three Gorges ◽  
Rainfall Runoff ◽  
Flood Peak ◽  
High Water Level ◽  
Three Gorges Region ◽  
Unit Hydrographs

After Three Gorges Reservoir building up, the natural river course and the near hillside inside the backwater region are inundated to form a fairly wide man-made lake which affects the hydrological characteristics and floodwater transmission to different degrees. When the reservoir impound to high water level, the conflux time is obviously shortened, the flood-peak discharge increase, and the peak type became sharper. The change of runoff yield and concentration makes the forecast scheme unable to be applied well. Based on the practice of Three Gorges Reservoir operation, the rainfall-runoff characteristics of the backwater region under the condition of high water level are analysed and summarized, then a set of unit hydrographs suitable for rainfall-runoff calculation are recalibrated, which has great reference value for hydrological forecasting of Three Gorges region.

Sign in / Sign up

Export Citation Format

Share Document