Seasonal changes of species- and guild-based benthic diatom communities in the transitional water zone of the Yellow River Delta.

Benthic diatoms serve as exemplary indicators for the assessment of ecological conditions in freshwater ecosystems. However, an approach to assessing and managing transitional water zones by benthic diatoms is relatively less. This study entailed a detailed analysis and comparison of the seasonal dynamics in species- and guild-based benthic diatom communities and their driving factors in a small-scale transitional water zone of the Yellow River Delta. Our findings revealed substantial seasonal variations in the composition and abundance of dominant species, as well as in the α and β diversity of the species-based community. Temperature emerged as the predominant environmental factor driving significant seasonal variations in the species-based community. However, no significant seasonal changes were observed in the composition and relative abundance of dominant guilds, as well as in the α, β, and functional diversity of the guild-based community. Redundancy analysis and Mantel tests demonstrated the guild-based community exhibited a stronger correlation with environmental factors compared to the species-based community. The guild-based community exhibited resilience to the influence of seasonal temperature fluctuations and exhibited a strong correlation with phosphate concentration variations. Our findings suggest that the guild-based community is a feasible approach to assessing ecological status across various seasons in the transitional water zone of the Yellow River Delta.