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

2021 ◽  
Vol 12 ◽  
Author(s):  
Yang Liu ◽  
Chengyan Li ◽  
Shenglong Jian ◽  
Shiyu Miao ◽  
Kemao Li ◽  
...  
Keyword(s):  
Community Structure ◽  
Hydrological Regime ◽  
Wiener Index ◽  
Plankton Community ◽  
Zooplankton Species ◽  
Cascade Reservoirs ◽  
Reservoir System ◽  
Drainage Rate ◽  
Reservoir Systems ◽  
Nutrient Conditions

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.

Bioaccumulation and Effects of Cadmium and Zinc in a Lake Michigan Plankton Community

1983 ◽  
Vol 40 (9) ◽  
pp. 1469-1479 ◽  
Author(s):  
J. S. Marshall ◽  
J. I. Parker ◽  
D. L. Mellinger ◽  
C. Lei
Keyword(s):  
Community Structure ◽  
Species Diversity ◽  
Lake Michigan ◽  
Plankton Community ◽  
Crustacean Zooplankton ◽  
Zooplankton Species ◽  
Community Similarity ◽  
Zooplankton Community Structure ◽  
Keratella Cochlearis ◽  
In Situ Experiments

We conducted four in situ experiments in the southern basin of Lake Michigan to determine the responses of the plankton community to additions of cadmium (3 μg/L) and zinc (15, 30, 60, and 90 μg/L) as well as the bioaccumulation of zinc by different species of crustacean zooplankton. Total cadmium and zinc concentrations in treated enclosures (accounting for pretreatment lakewater concentrations of ~ 20 ng Cd and ~ 1 μg Zn per litre) were calculated from measurements of 109Cd and 65Zn with known specific activities.Zinc significantly reduced zooplankton populations and several other properties of community structure and function at concentrations much lower than those previously reported to be toxic to zooplankton and well below the levels established for protection of freshwater life. Zinc additions as low as 15 μg/L significantly reduced chlorophyll a, primary productivity, dissolved oxygen, specific zooplankton populations, zooplankton species diversity, and community similarity within 2 wk. Populations of several zooplankton species were severely reduced by 15 μg/L; for example, the population of the rotifer Conochilus unicornis was reduced to less than 1% of that in controls. Secondary, indirect effects included significant increases of a few populations, including Bosmina longirostris and Keratella cochlearis, for zinc additions of 15 and 30 μg/L. Most of the populations and community properties that we measured showed somewhat different percentage reductions in response to a given zinc addition at different times, but their relative (rank) values at different times were similar. Specific zooplankton populations were more sensitive to zinc than community similarity indices, and species diversity indices were relatively insensitive. Bioaccumulation of zinc by different species of crustaceans increased with added zinc but showed few significant differences among species. The small differences among species could, nevertheless, partially account for some of the observed changes in zooplankton community structure.

Allelopathic and Medicinal plant. 26. Millettia speciosa

2020 ◽  
Vol 51 (2) ◽  
pp. 125-146
Author(s):  
Nasiruddin Nasiruddin ◽  
Yu Zhangxin ◽  
Ting Zhao Chen Guangying ◽  
Minghui Ji
Keyword(s):  
Community Structure ◽  
Medicinal Plant ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Wiener Index ◽  
Pseudomonas Spp ◽  
Evenness Index ◽  
Gradient Gel Electrophoresis ◽  
Rhizosphere Pseudomonas

We grew cucumber in pots in greenhouse for 9-successive cropping cycles and analyzed the rhizosphere Pseudomonas spp. community structure and abundance by PCR-denaturing gradient gel electrophoresis and quantitative PCR. Results showed that continuous monocropping changed the cucumber rhizosphere Pseudomonas spp. community. The number of DGGE bands, Shannon-Wiener index and Evenness index decreased during the 3rd cropping and thereafter, increased up to the 7th cropping, however, however, afterwards they decreased again. The abundance of Pseudomonas spp. increased up to the 5th successive cropping and then decreased gradually. These findings indicated that the structure and abundance of Pseudomonas spp. community changed with long-term cucumber monocropping, which might be linked to soil sickness caused by its continuous monocropping.

scholarly journals The Influence of Plankton Community Structure on Sinking Velocity and Remineralization Rate of Marine Aggregates

2019 ◽  
Vol 33 (8) ◽  
pp. 971-994 ◽  
Author(s):  
L. T. Bach ◽  
P. Stange ◽  
J. Taucher ◽  
E. P. Achterberg ◽  
M. Algueró‐Muñiz ◽  
...  
Keyword(s):  
Community Structure ◽  
Plankton Community ◽  
Marine Aggregates ◽  
Plankton Community Structure ◽  
Sinking Velocity

Optimal operation of reservoir systems using the Wolf Search Algorithm (WSA)

2019 ◽  
Vol 19 (5) ◽  
pp. 1396-1404 ◽  
Author(s):  
Edris Ahmadebrahimpour
Keyword(s):  
Genetic Algorithm ◽  
Water Resources Management ◽  
Simple Structure ◽  
Search Algorithm ◽  
Global Optimum ◽  
Optimal Operation ◽  
Resources Management ◽  
Reservoir System ◽  
Hydropower Plants ◽  
Reservoir Systems

Abstract Optimizing hydropower plants is complex due to nonlinearity, complexity, and multidimensionality. This study introduces and evaluates the performance of the Wolf Search Algorithm (WSA) for optimizing the operation of a four-reservoir system and a single hydropower system in Iran. Results indicate WSA could reach 99.95 and 99.91 percent of the global optimum for the four-reservoir system and single reservoir system, respectively. Comparing the results of WSA with a genetic algorithm (GA) also indicates WSA's supremacy over GA. Thus, due to its simple structure and high capability, WSA is recommended for use in other water resources management problems.

scholarly journals Introducing modified version of penguins search optimization algorithm (PeSOA) and its application in optimal operation of reservoir systems

2017 ◽  
Vol 18 (4) ◽  
pp. 1484-1496 ◽  
Author(s):  
Afshin Mansouri ◽  
Babak Aminnejad ◽  
Hassan Ahmadi
Keyword(s):  
Genetic Algorithm ◽  
Optimization Algorithm ◽  
Real World ◽  
Global Optimum ◽  
Optimal Operation ◽  
The Other ◽  
Reservoir System ◽  
Search Optimization ◽  
Real World Problem ◽  
Reservoir Systems

Abstract In the current study, modified version of the penguins search optimization algorithm (PeSOA) was introduced, and its usage was assessed in the water resources field. In the modified version (MPeSOA), the Gaussian exploration was added to the algorithm. The MPeSOA performance was evaluated in optimal operation of a hypothetical four-reservoir system and Karun-4 reservoir as a real world problem. Also, genetic algorithm (GA) was used as a criterion for evaluating the performance of PeSOA and MPeSOA. The results revealed that in a four-reservoir system problem, the PeSOA performance was much weaker than the GA; but on the other hand, the MPeSOA had better performance than the GA. In the mentioned problem, PeSOA, GA, and MPeSOA reached 78.43, 97.46, and 98.30% of the global optimum, respectively. In the operation of Karun-4 reservoir, although PeSOA performance had less difference with the two other algorithms than four-reservoir problem, its performance was not acceptable. The average values of objective function in this case were equal to 26.49, 23.84, and 21.48 for PeSOA, GA, and MPeSOA, respectively. According to the results obtained in the operation of Karun-4 reservoir, the algorithms including MPeSOA, GA, and PeSOA were situated in ranks one to three in terms of efficiency, respectively.

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