Significant changes in arbuscular mycorrhizal community and soil physicochemical properties during the saline-alkali grassland vegetation succession

Abstract

Arbuscular mycorrhizal (AM) fungi are widely distributed in various habitats, and the community composition varies in response to the changing environmental conditions. To explore the response of community composition to the succession of saline-alkali land, soil samples were collected from three succession stages of Songnen saline-alkali grassland. Subsequently, the soil characteristics were determined and the AM fungi in soil samples were analyzed by high-throughput sequencing. Then, the response relationship between community composition and soil characteristics was studied by Canonical correlation and Pearson analyses. The soil properties improved with the succession of saline-alkali grassland. There was no significant difference in alpha diversity between the first and second succession stage (Suaeda glauca and Puccinellia tenuiflora, respectively), and the microbial community had a dense association network at the third stage (Leymus chinensis); in addition, each succession stage had significantly enriched amplicon sequence variants (ASVs) and functional pathways. All the soil properties except cellulase activity had significant effects on community composition. Furthermore, the pH, organic carbon, organic matter, and sucrase activity significantly correlated with alpha diversity indices. These results provide a theoretical basis for realizing the significant changes in AM fungal community and soil properties during the saline-alkali grassland vegetation succession.