Abstract:

Based on daily meteorological data from 122 weather stations on the Qinghai−Tibet plateau from 1981 to 2020 and agricultural meteorological data from 4 agrometeorological stations on highland barley production, this study used an elevation component separation model to separate the elevation component of the climate tendency rates of temperature at each meteorological station. Using a parameter−calibrated APSIM−barley model, the study simulated the growth period and light−temperature potential yield of highland barley in the region. The stability coefficient of the light−temperature potential yield was used as an indicator to divide potential highland barley planting areas on the Qinghai−Tibet plateau, clarifying the relationships between the elevation component of temperature climate tendency rates and simulated highland barley growth period, light−temperature potential yield and stability coefficient of light−temperature potential yield. This study aimed to explore the impact of elevation−dependent warming on highland barley growth on the Qinghai−Tibet plateau, providing a theoretical basis for alleviating the conflict between food demand and limited arable land resources in the region and ensuring food security. The results showed that the APSIM−barley model after parameter calibration could accurately simulate highland barley growth. The coefficients of determination R² and RMSE between simulated and measured values were 0.764 and 2.17d for the duration from sowing to flowering, 0.641 and 1.85d for the duration from flowering to maturity, and 0.554 and 473.88kg·ha⁻¹ for the yield. APSIM−barley model could be used for subsequent analysis. The zoning results indicated that high and relatively high highland barley planting potential areas were mainly distributed in the northeastern, central−eastern and southern parts of Qinghai, the northern, northwestern and central parts of the Tibetan areas in western Sichuan, and the southern and southwestern regions of the Tibet Autonomous region. Overall, the simulated highland barley growth period, potential yield and stability coefficient of the potential yield showed the strongest positive correlation with the elevation component of the mean temperature climate tendency rates. The correlation coefficient r was 0.25 and 0.36 for the number of days from sowing to flowering and from flowering to maturity, respectively, while it was 0.37 and 0.36 for the potential yield and the stability coefficient of potential yield, respectively. This indicated that the elevation−dependent warming during the study period had been favorable for highland barley growth, with the greatest effect arising from the mean temperature climate tendency rate. By separating the elevation component of temperature climate tendency rates, this study provides a more accurate assessment of the impact of elevation−dependent warming on highland barley growth on the plateau. In the future, this can inform the adjustment of highland barley planting layouts, and the findings can offer scientific guidance for highland barley production on the Qinghai−Tibet plateau.

Key words: Qinghai?Tibet plateau, Highland barley, Elevation?dependent warming, APSIM?barley model, Planting potential