Xihui Sun

Ecological restoration of alpine mining areas is constrained by low temperature, infertile substrates, and limited water availability, yet the coordinated early responses of plants, soils, and microorganisms remain poorly understood. We conducted a 90-day in situ revegetation experiment in an alpine sand-and-gravel mine in Tibet using three native perennial grasses, Elymus nutans, Agropyron cristatum, and Festuca sinensis, established in monoculture and mixed-sowing treatments. Plant growth and physiology, soil physicochemical properties, nutrients, enzyme activities, and microbial communities were assessed. All three pioneer species established measurable biomass within the first growing season, although growth and physiological responses differed among planting configurations. Soil capillary porosity, moisture content, and water-holding capacity showed the most consistent improvements, whereas enzyme activities and nutrient responses were more treatment-dependent. Bacterial and fungal communities underwent significant reorganization, while inferred co-occurrence networks showed temporal topological restructuring and sensitivity to simulated targeted node removal. Mantel analysis showed that bacterial community variation was significantly associated with capillary porosity, non-capillary porosity, and total phosphorus, whereas fungal community variation was not significantly associated with the measured soil variables. Overall, 90 days of pioneer revegetation initiated measurable plant–soil–microbial recovery in the alpine mining substrate. Physical and hydrological properties showed clearer early responses than most nutrient indicators, while the observed associations between soil pore characteristics and bacterial community composition suggest a potential link between physical habitat changes and microbial community reassembly.

The tree peony, a novel woody oil crop extensively cultivated in China, necessitates further investigation into artificial pollination technology to enhance seed yield. In this study, we conducted artificial pollination experiments with 6-year-old Paeonia ostii ‘Feng Dan’ seedings for suitable pollen sources, pollen concentration, pollination timing, and pollination frequency. By evaluating seed yields, active ingredients, and oil quality, we derived the following significant conclusions. Firstly, compared to natural pollination, artificial pollination could significantly increase the fruit diameter by 13.94–27.58%, seed yields by 35.17–58.99%, and oil content by 6.45–7.52% in tree peonies. In active ingredients, seeds produced by pollen from Hantai County significantly enhanced starch content (by 48.64%), total phenols (by 41.18%) and antioxidant capacity (by 54.39%). In oil quality, seeds produced by pollen from Heyang County exhibited the highest α-linolenic acid and total fatty acid content with enhancements of 1.68%, 7.41%, and 8.48%. Secondly, hand pollination with pure pollen significantly increased seed yield by 58.99%, total phenol content by 40.97%, antioxidant capacity by 54.39%, and oil content by 1.53% compared to natural pollination. Thirdly, pollination at 2/3 bloom range significantly increased seed number by 63.08% and yield by 45.61% compared to natural pollination. Finally, the effect of one, two, and three pollination events had no difference in seed yield. So, to summarize, applying a 100% concentration of allochthonous pollen once is recommended when the bloom range is more than two thirds.