Variation in rhizosphere soil microbial index of tree species on seasonal flooding land: An in situ rhizobox approach

► Rhizosphere microbial activity was significantly affected by tree species. ► Rhizosphere soil microbial index (RSMI) could be a good indicator for selecting tree species. ► The tested tree species could be segregated into four groups based on RSMI values. ► In situ rhizobox approach is a valuable tool for sampling rhizosphere soil.