Diversity and distribution of bryophytes and their implications in ion-type rare earth mines in southern Jiangxi, China

Abstract Purpose Bryophytes play an important role in post-mining vegetation succession in metal-mining areas. As a pioneer group, bryophytes can prevent soil erosion, increase soil nutrition, and affect subsequent vegetation succession. This study investigated the diversity and distribution of bryophytes in the ion-type rare earth mining area of southern Jiangxi Province in southeast China to reveal the key environmental factors influencing vegetation restoration, the effect of vegetation restoration through community structure composition, and the most dominant and therefore suitable groups for vegetation restoration. Methods Investigations and sampling were carried out in five mining areas. In each area, the diversity and distribution of bryophytes in five typical habitats [virgin field (VF), orchard, ammonium deposition leaching (ADL), ammonium in situ leaching (AISL), and cropland] were analyzed. Results A total of 118 species of bryophytes belonging to 66 genera and 36 families were collected and identified. Endemic species were found in all habitats in the mining area, and the dominant bryophytes were common species in all habitats. The bryophyte diversity showed habitat-related changes, in the following order: cropland > orchard > VF > AISL > ADL. A structural equation model showed that soil moisture and slope location directly affected bryophyte diversity. Bryophyte communities in turfs and cushions were the dominant groups that adapted to the harsh post-mining environment. Edaphic factors had a greater influence on the bryophyte distribution than topographic and biological factors, at both the overall and habitat scale. Soil moisture was the most important factor affecting the overall distribution of bryophytes in the mining area. There were clear differences in the importance of factors affecting the bryophyte community structure in different habitats. Conclusion Although mining activities significantly reduce bryophyte diversity, bryophyte communities adapt to the lack of water and moisture by adjusting their life-form structure and species composition. The common species in mining areas might be suitable materials for local vegetation restoration. Deliberate manipulation of the terrain, nutrient supplementation, and reducing the concentrations of harmful substances will help accelerate the early succession of vegetation in leached soil.