Effects of dominant plant growth on the nutrient composition and bacterial community structure of manganese residues

Abstract

The rhizospheres of three dominant plant species (Miscanthus floridulus, Buddleja lindleyana, and Erigeron annuus) growing in manganese residue disposal sites in eastern Guizhou Province, China, were analyzed to study the effects of plant growth on the nutrient levels and bacterial community structure of two types of manganese residues. The results showed that the growth of the three species improved the nutritional composition of manganese residues; the available nitrogen (AN) contents of the manganese mine residue significantly increased by 29.56–60.78% while the available phosphorus (AP) contents of the electrolytic manganese residue significantly increased by 30.24–44.41% compared to those in unvegetated manganese residue. The diversity of the bacterial community in the manganese mine residue increased significantly due to plant growth. Proteobacteria, Acidobacteria, and Bacteroidetes were the dominant phyla in both manganese residues. Sphingomonas and GP6 were the dominant bacterial genera. The relative abundance of the Firmicutes phylum was significantly higher in the manganese mine residue than in the control and that of the Thiobacillus genus was lower, which indicated improvements in the microenvironment. Correlation analysis showed that OM and AN were the main nutrient factors affecting the bacterial community structure in the manganese mine residue.

Novelty statement At present, research on the phytoremediation of manganese residue disposal sites focuses mostly on the investigation of different plant types and their heavy metal accumulation and transformation characteristics. However, comparative studies of the differences in growth matrix characteristics between plant growth areas and exposed areas are lacking. In addition, dominant plant species are regionally distributed. The previous studies were mostly concentrated in Chongqing, Guangxi, and Hunan in China. The eastern region of Guizhou Province is located in the “Manganese Triangle” area of China, where the manganese resources account for about 50% of the national total. There is no report on the phytoremediation of manganese residue disposal sites in this region. Therefore, the rhizospheres of three dominant plant species (Miscanthus floridulus, Buddleja lindleyana, and Erigeron annuus) growing in manganese residue disposal sites in eastern Guizhou Province, China, were analyzed to study the effects of plant growth on the nutrient levels and bacterial community structure of two types of manganese residues (manganese mine residue and electrolytic manganese residue). This study could provide useful theoretical information to benefit the ecological restoration of manganese residue disposal sites.

Keywords:

• Bacterial community structure
• manganese residue
• dominant plant
• nutrients

Acknowledgments

The authors would like to thank American Journal Experts for providing English language, grammar, punctuation, and spelling help during the preparation of this manuscript.

Disclosure statement

No potential competing interest was reported by the authors.

Data availability statement

The numerical data used to support the findings of this study are included within the article.

Additional information

Funding

This work was funded by the National Natural Fund Committee—Guizhou Karst Science Research Center Project [U1612442-3], the National Natural Science Foundation of China [41661094] and Guizhou Education Department of China [KY(2018)255].