Do the regular annual extreme water level changes affect the seasonal appearance of Anabaena in Poyang Lake?

10.7287/peerj.preprints.27388v1 ◽

2018 ◽

Author(s):

Kuimei Qian ◽

Martin Dokulil ◽

Yuwei Chen

Keyword(s):

Water Temperature ◽

Water Level ◽

Poyang Lake ◽

Environmental Parameters ◽

High Water ◽

Water Level Change ◽

Extreme Water Level ◽

Level Change ◽

Heterocyst Frequency ◽

Water Level Changes

Background. Poyang Lake is an exceptional system exhibiting a water level change of up to 14 m every year. In the years 2013 and 2014 water level changes were 8.03 m and 11.22m respectively. The biomass of Anabaena and heterocyst frequency increased in the summers of recent years. Methods. A weekly or bi-weekly monitoring period from June to November 2013 and 2014 was set up to explain the reason for this phenomenon. Results. Anabaena was observed throughout the year. The average relative biomass of Anabaena in the study period was over 40%, being most abundant in summer. The average heterocyst frequency was 0.226% in 2013 and 0.760% in 2014. The SPSS analysis indicated a positive correlation of Anabaena biomass with water temperature and water level and negative one with TN, which is the reason for the increase of heterocyst frequency from 2013 to 2014. It also indicated that heterocyst frequency of Anabaena was positively correlated with water temperature, water level and PO4-P, and negatively with DIN/DIP, NO3-N and TN. At the same time, water temperature and DIN/DIP were significantly correlated with water level, which means that water level changes have a direct effect on Anabaena and its heterocyst formation in Poyang Lake. Conclusions. The results of the study support the hypothesis that increasing biomass and heterocyst formation of Anabaena were primarily caused by changes in the environmental parameters, such as high water temperature and suitable nutrients in summer and autumn, driven by the regular annual extreme water level change of Poyang Lake. The results can provide a theoretical basis for the management and utilization of Lake Poyang.

Download Full-text

Do the regular annual extreme water level changes affect the seasonal appearance of Anabaena in Poyang Lake?

10.7287/peerj.preprints.27388 ◽

2018 ◽

Author(s):

Kuimei Qian ◽

Martin Dokulil ◽

Yuwei Chen

Keyword(s):

Water Temperature ◽

Water Level ◽

Poyang Lake ◽

Environmental Parameters ◽

High Water ◽

Water Level Change ◽

Extreme Water Level ◽

Level Change ◽

Heterocyst Frequency ◽

Water Level Changes

Background. Poyang Lake is an exceptional system exhibiting a water level change of up to 14 m every year. In the years 2013 and 2014 water level changes were 8.03 m and 11.22m respectively. The biomass of Anabaena and heterocyst frequency increased in the summers of recent years. Methods. A weekly or bi-weekly monitoring period from June to November 2013 and 2014 was set up to explain the reason for this phenomenon. Results. Anabaena was observed throughout the year. The average relative biomass of Anabaena in the study period was over 40%, being most abundant in summer. The average heterocyst frequency was 0.226% in 2013 and 0.760% in 2014. The SPSS analysis indicated a positive correlation of Anabaena biomass with water temperature and water level and negative one with TN, which is the reason for the increase of heterocyst frequency from 2013 to 2014. It also indicated that heterocyst frequency of Anabaena was positively correlated with water temperature, water level and PO4-P, and negatively with DIN/DIP, NO3-N and TN. At the same time, water temperature and DIN/DIP were significantly correlated with water level, which means that water level changes have a direct effect on Anabaena and its heterocyst formation in Poyang Lake. Conclusions. The results of the study support the hypothesis that increasing biomass and heterocyst formation of Anabaena were primarily caused by changes in the environmental parameters, such as high water temperature and suitable nutrients in summer and autumn, driven by the regular annual extreme water level change of Poyang Lake. The results can provide a theoretical basis for the management and utilization of Lake Poyang.

Download Full-text

Factors influencing water level changes in China’s largest freshwater lake, Poyang Lake, in the past 50 years

Water International ◽

10.1080/02508060.2015.986617 ◽

2014 ◽

Vol 39 (7) ◽

pp. 983-999 ◽

Cited By ~ 22

Author(s):

Xuchun Ye ◽

Yunliang Li ◽

Xianghu Li ◽

Qi Zhang

Keyword(s):

Water Level ◽

Poyang Lake ◽

Freshwater Lake ◽

The Past ◽

Factors Influencing ◽

Water Level Changes ◽

Lake Poyang

Download Full-text

The effects of water-level changes on periphytic algal assemblages in Poyang Lake

Fundamental and Applied Limnology / Archiv für Hydrobiologie ◽

10.1127/fal/2020/1349 ◽

2020 ◽

Author(s):

Kuimei Qian ◽

Martin Dokulil ◽

Wan Lei ◽

Yuwei Chen

Keyword(s):

Water Level ◽

Algal Biomass ◽

Environmental Changes ◽

Poyang Lake ◽

Temporal Variations ◽

Algal Community ◽

Temperature Conductivity ◽

Periphytic Algae ◽

Water Level Changes ◽

Algal Assemblages

Poyang Lake, which is the largest freshwater lake in China, has a seasonal flooding cycle that significantlychanges the water level every year. The aim of this study was to research the effects of water-level changeson periphytic algal assemblages in Poyang Lake. Dynamic shift of periphytic algal biomass were studied fromNovember 2016 to July 2019. Periphytic algal biomass and species composition were analyzed microscopically, andphysicochemical conditions were measured. There were significant seasonal variations in the community distributionof periphytic algae. The biomass of the periphyton ranged from 8 to 22,636 mg m-2. Periphytic algal biomassranged from 30 to 622 mg m-2 with the average of 204 mg m-2 in the LWL phase; periphytic algal biomass rangedfrom 8 to 21,839 mg m-2, with the average of 3,399 mg m-2 in the IWL phase. It ranged from 166 to 22,636 mgm-2, with the average 4,320 mg m-2 in the HWL phase and from 16 to 3,231 mg m-2 with the average of 585 mgm-2 in the DWL phase. There were temporal variations in periphytic algal community structure in Poyang Lake.Cryptophyceae dominated in algal periphyton from November 2016 to February 2017. Bacillariophyceae dominatedfrom March to July 2017 (increasing water-level phases). Pyrrophyceae and Euglenophyceae were dominant fromAugust and September (high-water-level phase) in 2017. Bacillariophyceae dominated through 2018 with occasionaldominance of Cryptophyceae from January to June and the occasional dominance of Chlorophyceae fromJuly to December. Chlorophyceae dominated from January to July in 2019 with occasional dominance of Bacillariophyceae.The water-level variations led to environmental heterogeneity in Poyang Lake, creating heterogeneoushabitats for algal periphyton. Our study revealed the primary importance of water level, water temperature, conductivity,total nitrogen, nitrite and total phosphorus as abiotic local factors structuring the periphytic algal communityin Poyang Lake. The water-level changes did not prevent growth of periphytic algae, but it did change the periphyticalgal community assemblages. This research provides data on the periphytic algae in Poyang Lake and will beuseful for establishing biological indicators of environmental changes and protecting Poyang Lake in the future.

Download Full-text