The response of medium and trace elements in degraded alpine meadow soils to vegetation characteristics and soil physicochemical properties

Alpine meadows, one of the most widespread and important vegetation types on the Qinghai-Tibet Plateau, are facing severe degradation. This study examines how degradation affects soil medium and trace elements in the eastern Qinghai-Tibet Plateau, along with their relationships with plant traits and soil properties. Results indicate that alpine meadow degradation significantly reduces vegetation coverage, height, biomass, soil water content (SWC), and the levels of soil organic carbon (SOC), nitrogen (N), and phosphorus (P), while increasing soil bulk density (BD), pH, and potassium (K) content. Soil Ca, Zn, and Mo decrease with degradation, whereas Mg, Fe, Mn, Cu, Ni, and Co increase, with Ca, Fe, and Mn showing the strongest changes. Correlation and redundancy analyses indicate that aboveground biomass, SWC, SOC, N, and P positively correlate with Ca, Mo, and Zn, while pH, BD, and K associate with Mn, Fe, Ni, Co, Mg, and Cu. Therefore, alpine meadow degradation significantly influences the distribution of certain soil physicochemical properties and medium and trace elements in the eastern Qinghai-Tibet Plateau. Meanwhile, these medium and trace elements are also affected by specific soil physicochemical properties. Future grassland restoration should consider not only macronutrients and basic soil properties but also key elements like Ca, Fe, and Mn. This study provides foundational data for the ecological restoration of degraded alpine meadows.