Habitat heterogeneity shapes the differences in composition and structure of phytoplankton functional groups in...

The phytoplankton functional group (FGs) classification system can effectively characterize the ecological functions of communities and their environmental adaptability. However, existing classification systems for FGs have been predominantly developed and validated in temperate regions. In contrast, research in subtropical regions, which are characterized by unique hydrothermal conditions and a high incidence of harmful algal blooms, remains relatively limited. Specifically, the distribution characteristics of FGs in different water bodies in subtropical regions and their correlations with environmental factors remain unclear, which restricts the further development and improvement of the functional group system and its application. This study systematically explored the niche differentiation characteristics of FGs in different water bodies (rivers, lakes, streams, and reservoirs). The relationship between habitat heterogeneity and FGs was evaluated. Ultimately, Habitat templates for the dominant FGs in different water bodies were established. The findings are: 1) The composition, structure, and ecological niches of FGs in different water bodies exhibited significant spatiotemporal differences; 2) Habitat heterogeneity plays a significant role in shaping the composition and biodiversity of FGs; 3) The constructed habitat template focuses on five dominant FGs in each water body, with a clearer goal and direct correlation to the core ecological demands in subtropical regions. This study provides supplementary information for the existing FGs classification system in the subtropical region, offering a theoretical basis and practical guidance for the management of eutrophic water bodies and the targeted prevention and control of HABs.