Shuitu baochi tongbao (Dec 2023)
Effects of Desertification on Phosphorus Fractions of Alpine Meadow Soils
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.
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