The Differing Responses of Chlorophyta and Bacillariophyta to Available Resources Result in Diverse Community Patterns in Lakes Situated to the East of the Hu Line During the Autumn

Phytoplankton communities are of vital importance to the functioning of freshwater ecosystems, but the role of the metabolic capacity of the community in regulating community dynamics under natural conditions has yet to be sufficiently considered. This study investigated 26 lakes situated along the eastern section of the Hu Line, combining field surveys with metagenome-assembled analyses to ascertain the factors responsible for the divergence in Chlorophyta and Bacillariophyta communities. The results demonstrated that the diversity of Chlorophyta was markedly higher than that of Bacillariophyta whereas the abundance was significantly lower. These discrepancies in community attributes were predominantly attributable to variations in the response of the two algal groups to nutrients. The abundance and diversity of diatom metabolic genes were significantly higher than those of green algae. The greater diversity and extent of metabolic genes in Bacillariophyta confer enhanced metabolic capacity and, consequently, greater adaptive capacity. Such differences in metabolic gene composition may be attributed to the disparate evolutionary pathways that these organisms have followed.