Structural Characteristics of the Rhizosphere Soil Microbial Community in Naturally Colonized Liana within Abandoned Iron Mines

Abstract

Lianas play a critical role in vegetation restoration of mining areas​. To investigate the rhizosphere soil microbial characteristics during ecological recovery, this study focuses on three naturally colonized lianas in abandoned iron mines of Longmen County, Guangdong,including Smilax china L., Paederia foetida L. and Pericampylus glaucus (Lam.) Merr. High throughput sequencing technology was used to analyze the diversity characteristics and community structure of soil bacteria and fungi. Soil related physical and chemical indicators were measured. This article compared and analyzed the physicochemical properties and microbial community composition of rhizosphere soil of different lianas, and explored their interactions and key driving factors. Results indicated that Smilax china L. exhibited higher organic matter (5.53 g/kg), total nitrogen (0.47 g/kg), total phosphorus (0.20 g/kg), total potassium (5.14 g/kg) and alkali-hydrolyzable nitrogen (44.53 mg/kg) compared with the other species. Chloroflexia and Ascomycetes are the most abundant bacterial and fungal phyla in the rhizosphere soil of Smilax china L. and Pericampylus glaucus (Lam.) Merr. Alpha diversity analysis revealed that Smilax china L. had the highest bacterial richness and fungal evenness, whereas Paederia foetida L. showed the highest fungal richness. LEfSe analysis of bacterial and fungal communities revealed that the rhizosphere soil of Smilax china L. exhibited significantly higher relative abundances of Acidipila and Umbelopsis compared with the other two liana species. Correlation analysis demonstrated that soil total nitrogen, total phosphorus, total potassium and alkali-hydrolyzable nitrogen were the key environmental factors significantly influencing the structure of soil microbial communities. These findings provide scientific insights for vegetation restoration and ecosystem reconstruction in abandoned mining areas.

Keywords: Iron mine wasteland, Lianas, Soil microorganism, Soil physicochemical index