Drought Resistance Evaluation of Dominant Species in Inner Mongolia Desert Steppe During Seed Germination
This study evaluated the drought resistance of seven dominant plant species from the Inner Mongolia desert steppe during seed germination to identify suitable species for ecological restoration of arid mining dumps. Seeds were subjected to soil moisture gradients ranging from 2.56% to 12.77% to simulate drought stress. Germination percentage, growth parameters, germination index, simplified vigor index, and drought resistance index were measured. A multi-dimensional evaluation system was constructed using the membership function method. Results showed that with increasing water stress, germination parameters generally declined nonlinearly. Under severe drought (soil moisture 5.11%), Lolium perenne and Melilotus officinalis exhibited significantly higher germination rates than other species (P<0.05). Comprehensive evaluation ranked drought resistance as: Lolium perenne > Melilotus officinalis > Setaria viridis > Elymus dahuricus > Medicago sativa > Astragalus adsurgens > Artemisia oxycephala. These findings indicate that Lolium perenne, Melilotus officinalis, and Setaria viridis possess strong drought resistance and can serve as pioneer species for vegetation reconstruction in mining areas. Furthermore, a soil moisture content of 5.11% (40% of field capacity) was identified as the lower threshold for seed germination, providing a quantitative basis for water management in arid mining ecological restoration.