Microbial Communities in Forest and Wetland Soil Types Display Divergent Trends in Diversity and Unique Functional Responses to Varying Carbon-to-Nitrogen Ratios

Abstract

The carbon-to-nitrogen (C:N) ratio is a critical environmental factor influencing microbial growth, nutrient availability, and community dynamics. This study investigates the impact of C:N ratio variations on microbial diversity, taxonomic composition, and functional potential in forest and wetland soils. By examining 16S rRNA sequences from datasets of these contrasting environments, the purpose was to understand ecosystem-specific responses to changing nutrient conditions, specifically changes in carbon and nitrogen. Beta diversity analysis revealed distinct clustering of microbial communities between soil types, underscoring their compositional differences. In forest soils, the higher C:N ratio range was associated with decreased phylogenetic diversity, evenness, and functional pathway diversity, alongside upregulation of antibiotic synthesis pathways, indicating a competitive and volatile microbial environment. Conversely, wetland soils exhibited increased phylogenetic diversity with stable functional pathway diversity with increasing C:N ranges, suggesting functional redundancy despite taxonomic shifts. These findings demonstrate ecosystem-specific responses to C:N ratios, with forest soils displaying increased microbial competition and wetlands maintaining functional stability. This work highlights the importance of comparative studies to elucidate the interplay between nutrient dynamics and microbial ecology in diverse soil environments.