Effects of vegetation type on soil carbon, nitrogen, and microbial diversity in constructed wetlands during early restoration

(2) Compared with that in the control, bacterial Chao1 index increased by 27.5% and 31.7% in the PA and OS treatments, respectively, while fungal Inverse Simpson index decreased by 54.0% and 55.6%, respectively. In the SM treatment, only bacterial diversity indices (Shannon, Simpson, and Inverse Simpson indexes) decreased by 25.8%, 6.1%, and 94.9%, respectively, with no differences in fungal diversity. (3) Soil carbon and nitrogen contents were positively correlated with functional gene abundances and silt+clay content, but negatively correlated with bacterial abundance.

Vegetation type significantly altered soil texture (silt+clay content decreased by 12.3% – 18.6%) and redox conditions (Eh decreased by 24.1% – 34.8%), thereby restructuring microbial communities. These findings provide a theoretical basis for plant species selection and carbon-nitrogen regulation during the early stage of constructed wetland restoration.