草业学报2026，Vol.35Issue(5)：85-98,14.DOI:10.11686/cyxb2025230
降水变化对荒漠草原土壤有机碳分布与有机碳库稳定性的影响
Effects of precipitation changes on the soil organic carbon distribution and stability of organic carbon pool in desert steppe
摘要
Abstract
The aims of this work were to investigate the regulatory mechanisms of soil organic carbon(SOC)dynamics in a desert steppe ecosystem,and to determine how they are affected by changes in precipitation.This is critical for advancing our understanding of carbon(C)cycling processes and stabilization mechanisms in vulnerable arid environments.A field experiment was conducted in the desert steppe in Yanchi County,Ningxia.A gradient of five precipitation levels was simulated by rain shelter technology;namely 33%,66%,100%,133%,and 166%of normal rainfall(designated as P33,P66,PCK,P133,and P166,respectively).The distribution pattern of SOC and the stability of the C pool under different precipitation changes in the desert steppe were analyzed,and the mechanisms by which changes in precipitation affected the stability of the soil C pool were explored.The results showed that:1)Under all precipitation treatments,the contents of SOC,soil dissolved organic C(DOC),and soil microbial biomass C(MBC)decreased with increasing soil depth,and all these parameters had the highest values in the surface layer(0-10 cm).In the same soil layer,water addition significantly increased SOC,the easily oxidized soil organic C(EOC)content,and MBC content,while the DOC content increased significantly under reduced precipitation treatments.2)The stability index of the soil C pool showed that increased precipitation treatments significantly increased the carbon pool activity(CA)and carbon pool management index(CPMI).The CPMI of the P133 treatment reached 192.49%,indicating that a moderate increase in precipitation could enhance the stability of the C pool.3)Pearson's correlation analysis and structural equation modeling(SEM)showed that precipitation affected the active SOC components through soil moisture and soil enzyme activity,which in turn affected CPMI;the effect of DOC on CPMI was the main pathway.Therefore,increased precipitation can effectively enhance the active SOC components and CPMI of soil in the desert steppe.Notably,active SOC was highly sensitive to variations in precipitation,so it can serve as an indicator of the effect of changes in precipitation on the stability of the soil C pool in the desert steppe.关键词
荒漠草原/降水变化/土壤有机碳组分/碳库稳定性Key words
desert steppe/precipitation change/soil organic carbon components/carbon pool stability引用本文复制引用
连佳丽,陈婧,杨雪琴,赵莹,罗叙,韩翠,李建平..降水变化对荒漠草原土壤有机碳分布与有机碳库稳定性的影响[J].草业学报,2026,35(5):85-98,14.基金项目
宁夏自然科学基金(2023AAC03092)和银川市重点研发项目(2023NYZC01)资助. （2023AAC03092）
