Cyanobacteria in lakes on Yungui Plateau, China are assembled via niche processes driven by water physicochemical property, lake morphology and watershed land-use.

Jingqiu Liao,Jinhua Sun,Hao Fan,Dalin Jiang,Lei Zhao,Zhe Gao,Yi Huang,Jie Wang,Xiaofeng Cao

doi:10.1038/srep36357

Abstract

Plateau lakes are important ecosystems with diverse ecological functions. Cyanobacteria play a key role in plateau lakes as primary producers. However, they are threatening when dense blooms occur. Identifying cyanobacteiral biogeography and the mechanism of assembly processes shaping the distribution of cyanobacteria in plateau lakes is critical for understanding cyanobacterial ecology and applying it to lake management. In the present study, the biogeographic pattern and importance of neutral and niche processes in assembly of cyanobacteria in 21 lakes on Yungui Plateau, China were examined. Results showed that cyanobacteria exhibit unique biogeographic pattern, and most of them have a narrow habitat preference in plateau lakes. They were assembled via niche processes driven by water physicochemical property, lake morphology and watershed land-use, which explained 62.4% of the biological variation. Neutral processes were not at play. Water physicochemical property (key variables - dissolved oxygen, salinity, trophic status and pH) was the most dominant driver shaping its unique biogeographic pattern. Watershed land-use especially urban land, water body and agricultural land also exhibited a strong impact on cyanobacterial distribution, followed by lake morphology. As most of the cyanobacteiral genus detected in these plateau lakes were potential toxin-producers, this study indicated that in order to protect waters from toxic-bloom in the future, reducing nutrient loading and land-use practices are two practical approaches in plateau lake management.

Highlights

Cyanobacteria are autotrophic prokaryotes that establish themselves in a wide range of terrestrial and aquatic ecosystems due to their high adaptability[1,2,3]
We presented the first study describing the biogeographic pattern of cyanobacteria in numerous plateau lakes, a rarely explored environment
This study would deepen the understanding of the ecology of cyanobacteria, limnology of plateau lake, and benefit the watershed management

Summary

Introduction

Cyanobacteria are autotrophic prokaryotes that establish themselves in a wide range of terrestrial and aquatic ecosystems due to their high adaptability[1,2,3]. Lakes on the Yungui Plateau, located in southwest of China, possess a wide range of environmental and geographic gradients Their natural and anthropogenic conditions and geographic locations are ideal for investigating the effect of environmental and neutral factors on the distribution of cyanobacteria. These lakes serve as important ecosystems for providing numerous habitats for organisms and drinking water sources for local residence after desalination[27]. The aims of this study were to (1) describe the diversity and distribution of cyanobacteria in multiple plateau lakes, (2) clarify the assembly mechanism for cyanobacterial taxa, (3) quantify the importance of deterministic and neutral drivers shaping the biogeography of cyanobacteria. It will provide critical information for effective management of plateau lakes, such as eutrophication control and toxic-bloom warning

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Methods

Results

Conclusion