Seasonal dynamics of soil organic carbon and microbial communities in different Viburnum stands

Soil organic carbon and microbial communities in different Viburnum stands were studied to provide relevant data support for optimizing urban landscape plant configuration. In this study, four Viburnum species (Viburnum dilatatum, Viburnum keteleeri, Viburnum corymbiflorum, Viburnum rhytidophyllum) were selected as the research subjects, and the seasonal changes (spring, summer, autumn) of soil organic carbon and microbial communities were investigated with surrounding grassland as control. The results showed that soil organic carbon content in different Viburnum stands was higher than that of grassland, indicating that planting Viburnum in urban gardens was helpful to soil carbon sequestration. Total PLFAs in different Viburnum stands differed significantly, with Viburnum keteleeri having the highest total PLFAs, notably exceeding other treatments during spring and autumn. Planting Viburnum keteleeri could significantly increase subsurface soil G⁺, G⁻ bacteria, fungi, and actinomycetes contents. Compared with grassland, the increasing trend of soil microbial community in Viburnum keteleeri froest was fungi (68.11%) > actinomycetes (61.67%) > G⁻ bacteria (52.77%) > G⁺ bacteria (40.07%) > mycorrhizal biomass (25.00%). Planting Viburnum keteleeri could effectively improve soil microbial community structure, particularly fungi and actinomycetes, compared with Viburnum dilatatum, Viburnum rhytidophyllum, and Viburnum corymbiflorum. Conclusion: Different Viburnum stands had significant difference on soil organic carbon and microbial communities. Planting Viburnum keteleeri could improve soil organic carbon content and increase the total amount and richness of soil microbial community.