Storage,pattern and driving factors of soil organic carbon in the desert rangelands of northern Xinjiang,north-west China  

作　　者：Huixia LIU Zongjiu SUN Yuxuan CUI Yiqiang DONG Panxing HE Shazhou AN Xianhua ZHANG 

机构地区：[1]College of Grassland Sciences,Xinjiang Agricultural University,Urumqi 830052,China [2]Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology,Urumqi 830052,China [3]Xinjiang Key Laboratory of Grassland Resources and Ecology,Urumqi 830052,China

出　　处：《Frontiers of Earth Science》2024年第3期598-610,共13页地球科学前沿（英文版）

基　　金：funded by the Open Project of Key Laboratory of Xinjiang Uygur Autonomous Region(No.2022D04003);the National Basic resource survey of China(No.2017FY100200);the National Natural Science Foundation of China(Grant No.32060408);the graduate scientific research and innovation project of Xinjiang Agricultural University(No.XJAUGRI2021003).

摘　　要：Soil organic carbon(SOC)is a critical variable used to determine the carbon balance.However,large uncertainties arise when predicting the SOC stock in soil profiles in Chinese grasslands,especially on desert rangelands.Recent studies have shown that desert ecosystems may be potential carbon sinks under global climate change.Because of the high spatial heterogeneity,time-consuming sampling methods,and difficult acquisition process,the relationships the SOC storage and distribution have with driving factors in desert rangelands remain poorly understood.Here,we investigated and developed an SOC database from 3162 soil samples(collected at depths of 0−10 cm and 10−20 cm)across 527 sites,as well as the climate conditions,vegetation types,and edaphic factors associated with the sampling sites in the desert rangelands of northern Xinjiang,north-west China.This study aims to determine the SOC magnitude and drivers in desert rangelands.Our findings demonstrate that the SOC and SOC density(SOCD)were 0.05−37.13 g·kg^(-1)and 19.23−9740.62 g·m^(-2),respectively,with average values of 6.81±5.31 g·kg^(-1)and 1670.38±1202.52 g·m^(-2),respectively.The spatial distributions of SOC and SOCD all showed gradually decreasing trends from south-west to north-east.High-SOC areas were mainly distributed in the piedmont lowlands of the Ili valley,while low-SOC regions were mainly concentrated in the north-west area of Altay.The redundancy analysis results revealed that all environmental factors accounted for approximately 37.6%of the spatial variability in SOC;climate factors,vegetation factors,and soil properties explained 15.0%,1.7%,and 12.3%,respectively.The structural equation model(SEM)further indicated that evapotranspiration,average annual precipitation,and the SWC were the dominant factors affecting SOC accumulation,mainly through direct effects,although indirect effects were also delivered by the vegetation factors.Taken together,the results obtained herein updated the SOC data pool available for desert rangelands an

关 键 词：soil organic carbon desert rangeland SEM analysis driving factors Xinjiang Uygur Autonomous Region of China 

分 类 号：S153.6[农业科学—土壤学]