• • Drought resistance ranking: Lolium perenne > Melilotus officinalis > Setaria viridis > Elymus dahuricus > Medicago sativa > Astragalus adsurgens > Artemisia oxycephala, based on membership function analysis integrating germination rate, vigor index, and drought resistance index.
• • Under severe drought (soil moisture 5.11%, 40% field capacity), Lolium perenne and Melilotus officinalis showed significantly higher germination rates (P<0.05), indicating superior tolerance for arid restoration.
• • The lower soil moisture threshold for seed germination is 5.11% (40% of field capacity); however, optimal irrigation range is 5.11%–10.22% (40%–80% field capacity) to balance water use efficiency and seedling vigor.
• • Nonlinear threshold effects were observed: germination parameters declined nonlinearly with decreasing moisture, highlighting the need for precise water management in mine dump restoration.