【摘要】 [目的]土壤磷素组分决定着土壤演变过程中磷素的迁移和可用性。探讨高寒草甸不同退化程度下土壤磷组分的空间分布特征，为沙化草甸植被恢复提供科学参考。[方法]以青藏高原若尔盖沙化高寒草甸土壤为研究对象，采用修正后的Hedley磷素分级方法，探究未沙化、轻度、中度和重度沙化程度下高寒草甸土壤磷组分变化。[结果]（1）随着沙化程度的加剧，土壤有机碳、全氮、全磷、速效磷及含水量显著降低（p<0.05）;pH值显著升高（p<0.05）。（2）土壤树脂态磷（Resin-Pi）、碳酸氢钠磷（NaHCO₃-P）、氢氧化钠磷（NaOH-P）、稀盐酸无机磷（D.HCl-Pi）和浓盐酸磷（C.HCl-P）含量随沙化程度的加剧均出现显著（p<0.05）下降，其中在中度和重度沙化下有机磷组分含量较无机磷下降更为明显。（3）相关性分析显示，在高寒草甸沙化过程中土壤磷素组分的转化主要发生在D.HCl-Pi, NaHCO₃-P与氢氧化钠有机磷（NaOH-Po）组分之间；而HCl-P,NaOH-P和Resin-Pi是植物生长重要的磷源。[结论]沙化对土壤碳氮、水分、pH值和磷素组分有显著影响，沙化导致土壤碳氮、水分及pH值和磷素组分发生不同程度的变异，且多发生于沙化中后期；在高寒草甸沙化土壤中HCl-P,NaOH-P和Resin-Pi是植物生长重要的磷源。更多还原

【Abstract】 [Objective] Soil phosphorus fractions determine the migration and availability of phosphorus during soil evolution. The spatial distribution characteristics of soil phosphorus fractions in alpine meadows under different desertification levels were studied in order to provide a scientific reference for vegetation restoration in sandy meadows. [Methods] The modified Hedley phosphorus classification method was used to determine changes in phosphorus fraction in alpine meadow soils under different degrees of desertification（non-desertification; and light, medium and heavy desertification） using desertifed Zoige alpine meadow soils on the Qinghai-Tibet Plateau. [Results]（1） Soil organic carbon, total nitrogen, total phosphorus, active phosphorus, and water content decreased significantly（p<0.05） with increasing sand content; pH value increased significantly（p<0.05）.（2） Soil Resin-Pi, NaHCO₃-P, NaOH-P, D.HCl-Pi, and C.HCl-P contents all decreased significantly（p<0.05） with increasing sand content. Organic phosphorus fractions decreased more significantly than inorganic phosphorus fractions under moderate and severe desertification.（3） Correlation analysis showed that the conversion of soil phosphorus fractions during desertification in alpine meadows occurred mainly between D.HCl-Pi and NaHCO₃-P and NaOH-Po. HCl-P, NaOH-P, and Resin-Pi were important phosphorus sources for plant growth. [Conclusion] Desertification produced significant effects on soil carbon, nitrogen, moisture and pH value, and on phosphorus fractions. Desertification also produced different degrees of variability in soil carbon, nitrogen, moisture, and pH value, and on phosphorus fractions, and mostly occurred in the middle and late stages of desertification. HCl-P, NaOH-P, and Resin-Pi were important phosphorus sources for plant growth in desertified alpine meadow soils.更多还原