Biogeographic distribution patterns of algal community in different urban lakes in China: Insights into the dynamics and co-existence

Urban lake ecosystems are significant for social development,but currently we know little about the geographical distribution of algal community in urban lakes at a large-scale.In this study,we investigated the algal community structure in different areas of urban lakes in China and evaluated the influence of water quality parameters and geographical location on the algal community.The results showed that obvious differences in water quality and algal communities were observed among urban lakes in different geographical areas.Chlorophyta was the dominant phylum,followed by cyanobacteria in all areas.The network analysis indicated that algal community composition in urban lakes of the western and southern area showed more variations than the eastern and northern areas,respectively.Redundancy analysis and structural equation model revealed that nutrients and p H were dominant environmental factors that affected the algal community,and they showed higher influence than that of iron,manganese and COD Mn concentration.Importantly,algal community and density exhibited longitude and latitude relationship.In general,these results provided an ecological insight into large-scale geographical distributions of algal community in urban lakes,thereby having potential applications for management of the lakes.

Temporal patterns of algae in different urban lakes and their correlations with environmental variables in Xi’an,China

Urban lakes were critical in aquatic ecology environments,but how environmental factors affected the distribution and change characteristics of algal communities in urban lakes of Xi’an city was not clearly.Here,we investigated the algal community structure of six urban lakes in Xi’an and evaluated the effects of water quality parameters on algae.The results indicated that the significant differences on physicochemical parameters existed in different urban lakes.The maximum concentration of total phosphorus in urban lakes was(0.18±0.01)mg/L and there was a phenomenon of phosphorus limitation.In addition,51 genera of algae were identified and Chlorella sp.was the dominant algal species,which was affiliated with Chlorophyta.Network analysis elucidated that each lake had a unique algal community network and the positive correlation was dominant in the interaction between algae species,illustrating that mature microbial communities existed or occupied similar niches.Redundancy analysis illustrated that environmental factors explained 47.35% variance of algal species-water quality correlation collectively,indicating that water quality conditions had a significant influence on the temporal variations of algae.Structural equation model further verified that algal community structure was directly or indirectly regulated by different water quality conditions.Our study shows that temporal patterns of algal communities can reveal the dynamics and interactions of different urban ecosystem types,providing a theoretical basis for assessing eutrophication levels and for water quality management.