Unveiling Phytoplankton Diversity: Taxonomy, Functional Groups, and Environmental Drivers in North China Lakes

Functional groups (FGs) represent a classification scheme designed to study the ecological adaptations of phytoplankton. However, FG dynamics studies in phytoplankton are often conducted independent of taxonomic studies, so the factors influencing community dynamics have not been sufficiently investigated or compared between the two classification systems. In this study, we compared the intricate relationship between taxonomic and FG compositions in North China lakes and delve into the key environmental drivers shaping phytoplankton community dynamics. This investigation revealed that taxonomic and FG classifications exhibit high qualitative and quantitative similarities in the community structure. Environmental drivers had a stronger influence on the FG structure than taxonomic composition, indicating that the FG classification does not result in the loss of ecological information regarding the community structure, even with the reduced number of grouping units. Indeed, it was evident that FGs contained a larger quantity of ecological information. These conclusions were further verified using lakes in eastern China. Additionally, we found that climatic-geographical factors usually exerted indirect influences, by altering water chemistry, while water chemical factors had more direct and stronger influences. The combined effects of both types of environmental factors had a greater impact on the phytoplankton FG structure than on taxonomic composition. In conclusion, we believe that an in-depth study of FGs will better focus on the ecological characteristics of phytoplankton, while also avoiding the need for extensive species identification.