The mining of manganese brings excellent wealth to humankind. However, it destroys the ecological environment, mainly manifested as heavy metal pollution and vegetation destruction. The restoration of ecological vegetation in manganese mining areas has become an important work after mineral exploitation. The effect of bryophytes on ecological restoration in mining areas is irreplaceable. The bryophytes diversity and its pioneering role in two types of manganese waste residue areas were investigated in Guizhou province, China. The results showed that there were 24 species of mosses in mine waste slag areas, and all of them belonged to 6 families and 15 genera; the species Gymnostomum subrigidulum, Pohlia gedeana, and Bryum atrovirens were the dominant mosses. There were 6 species of mosses in electrolytic manganese slag areas, and all of them belonged to 5 families and 5 genera. The dominant moss was B. atrovirens. The bryophytes diversity in the electrolytic manganese slag areas with lower pH was poorer than that in mine slag areas. The accumulation of heavy metals in mosses showed that B. atrovirens collected from two types of areas had a strong ability to accumulate Mn with the cumulants 5588.00μg/g and 4283.41μg/g, respectively. All mosses had a strong enrichment ability to Cd. It indicated that mosses had strong tolerance to heavy metals. Bryophytes increased the available nutrients and bacterial community diversity of mosses growth substrates in two types of areas. Besides, we studied the relationships between bacterial community structure and soil factors. The main soil factor affecting the bacterial community structure was available nitrogen (AN) in mine waste slag areas, while it was pH in the electrolytic manganese residue areas. The systematic study suggested that bryophytes increased the available nutrients and the microbial community diversity of the growth substrates in manganese waste residue areas, which provided the basic conditions for the growth of vascular plants.

The high concentration Fe³⁺ in sample had interference on the determination of iron species by spectrophotometric method in which 1,10-phenanthroline was used to as a chromogenic agent. The F⁻ could mask absolutely the effect of Fe³⁺ when F⁻/Fe³⁺ molar concentration ratio was 13.3. The temperature or light did not affect the masking action of F⁻. Low temperature and dark conditions favored the stability of chromophoric complex. This method is suitable for the measure of iron species where the concentration of Fe³⁺ is far more than that of Fe²⁺ in samples.

Chemical fertilizer is widely used in agricultural fertilization, but over-fertilization has caused soil quality degradation. Some studies have shown that the application of organic fertilizer is beneficial to soil quality, but there are few studies researching the long-term organic fertilizer application effect on tea plantation soil. In this paper, we studied the physical and chemical properties and microbial communities of tea plantation soil through long-term field experiments by applying organic fertilizer with equal nitrogen amounts. The experiment showed that the soil’s physical and chemical properties were improved after long-term application of total organic fertilizer. Respectively, the soil organic matter (SOM), available potassium (K), available zinc (Zn), available copper (Cu), and pH were significantly enhanced, the soil bulk density was significantly increased, the water-stable aggregates were improved, the soil microbial diversity was increased. It was found that the main bacteria in tea soil were Proteobacteria, Acidobacteria, and Actinobacteria. Moreover, results from redundancy analysis showed t hat t he S OM ( p = 0 .001), A lkali h ydrolyzed n itrogen ( p = 0 .049) a nd p H ( p = 0 .008) h ad significant effects on the soil bacterial community composition. Thus SOM increased the relative richness of non-dominant bacteria, such as Bacteroidetes, Gemmatimonadestes, and Firmicutes. Overall, our results suggest that the use of organic fertilizer instead of chemical fertilizer could effectively improve the quality of tea plantation soil.