Response of bacterial communities in desert grassland soil profiles to acid mine drainage pollution

Abstract

Acid mine drainage (AMD) causes serious environmental pollution, which imposes stresses on soil ecosystems. Therefore, it is critical to study the responses of soil bacterial communities to AMD pollution in ecologically fragile desert grasslands. Here, the bacterial community composition, structure, and assembly processes in vertical soil profiles of an AMD contaminated desert grassland were explored using 16S rRNA high-throughput sequencing. The results showed that the surface layers of the profiles exhibited lower pH and higher heavy metals (HMs) content due to AMD influence. The AMD contamination led to reduced bacterial diversity in the surface soil layer of the profiles and significantly changed the bacterial community composition and structure. Gradients in pH, TK, TN, and HMs were the main factors driving bacterial community variability. In contrast to the uncontaminated profile, deterministic processes were important in shaping soil bacterial community in the AMD contaminated profiles. These findings will enhance understanding about the responses of soil bacteria in desert grassland soil to the environmental changes caused by AMD contamination and will improve the remediation of AMD contaminated soil.