Raw_data_Biolog_sediment_water_chemistry.xlsx

Is microbial functional diversity in urban freshwater ecosystems compromised by increased winter salinity?

Abstract

This study investigates the impact of winter salinization on the functional diversity of sediment microbial communities in urban freshwater ponds. Sediment samples from four ponds in Lodz, Poland, were analysed for microbial activity, and pore water and sediment chemistry, between seasons. Functional diversity was assessed based on carbon substrate utilization using the Biolog Eco-Plate™ technique. The results revealed significant seasonal variation in microbial activity, with lower mean well colour development (AWCD) and diversity indices (Shannon and substrate richness) noted during winter, which may be due to salinity. Organic carbon (Corg) appears to be a key factor positively influencing microbial diversity, while the Corg/N ratio was negatively correlated with diversity, indicating nutrient imbalances. These findings highlight the vulnerability of urban freshwater ecosystems to winter salinization and underscore the need for mitigation strategies to preserve microbial functional diversity and ecosystem resilience.

Key words: Carbon utilization, Ecosystem resilience, Freshwater salinization, Microbial diversity, Road salt, Sediments, Urban freshwater