Bioaccumulation of four metals in the same genus mosses (Barbula Hedw.) and soil pollution assessment in an abandoned karst bauxite tailing area

: Soil metal pollution is a concern in bauxite tailing areas. This study aimed to effectively screen plants with strong tolerance to metal contamination by analyzing the levels of metals in Barbula rigidula (Hedw.) Mild. (BR), Barbula indica (Hook.) Spreng. (BI), and Barbula vinealis Brid. (BV) and in soils. The contents of metals in mosses obtained from the bauxite tailing area followed the following order: Al > Fe > Zn > Cu. Furthermore, the levels of these metals were highest in BR, followed by BI and BV. However, concentrations of Al (12,220–87,080 mg/kg), Fe (8520–62,690 mg/kg), Cu (98.5–185.4 mg/kg), and Zn (208.2–352.6 mg/kg) in soils greatly exceeded the background values. Bioconcentration factor (BCF) analysis showed that the uptake ability of mosses was 0.44–1.51, with BR having the highest uptake ability, especially for Al and Fe. The metal contamination factor (CF) in soils was 2.04–15.12, indicating that the soil was exposed to moderate to severe contamination. Correlation analyses found that Al and Fe levels in BR and soil were significantly positively correlated ( r = 0.898). PCA also confirmed that BR is a bioindicator and phytoremediation material of polluted soil in an abandoned karst bauxite tailing.