荒漠河岸林土壤碳的分布受到多重因素的影响。以黑河下游额济纳绿洲为研究区域，通过采集20个胡杨林样地0～100 cm土层土壤样品，研究了土壤有机碳(SOC)、土壤无机碳(SIC)的空间分异特征及其影响因素。结果表明:(1)0～100 cm SOC和SIC均值分别为2。90 g·kg-1和10。79 g·kg-1，SIC为SOC的3。72倍。(2)垂直方向上SOC和SIC随土壤深度增加而减少，水平方向上从东河上段至下段SOC与SIC虽然均呈现减少趋势，但SIC总量仍大于SOC，说明SIC是干旱区内陆河下游土壤碳的主要赋存形式。(3)土壤理化性质对SOC的解释程度较高，而对SIC的解释程度较低。其中，土壤化学性质(EC、Na+、SO42-、Cl-、Ca2+、Mg2+、K+)对SOC的影响程度最大。综上，黑河流域下游荒漠河岸林土壤碳库是以SIC为主，且在水平和垂直方向存在明显的空间分异，土壤理化性质对SOC和SIC空间分异的影响存在差异。其中，碱性阳离子是影响SOC的主要因素，而土壤砂粒含量和容重是影响SIC的主要因素。
Spatial differentiation and its influencing factors of soil carbon in Populus euphratica Oliv.forest in the lower reach of Heihe River
The distribution of soil carbon in desert riparian forests is shaped by multiple factors.This study exam-ines the Ejina Oasis in the lower reaches of the Heihe River,China.Soil samples from 20 Populus euphratica Oliv.plots at depths of 0-100 cm were analyzed to investigate the spatial variation of soil organic carbon(SOC)and soil inorganic carbon(SIC)and their influencing factors.The results reveal:(1)The mean SOC and SIC contents in the 0-100 cm soil layer were 2.90 g·kg-1 and 10.79 g·kg-1,respectively,with SIC being 3.72 times of SOC.(2)Verti-cally,both SOC and SIC contents exhibited a declining trend with increasing soil depth,while horizontally,SOC and SIC from the upper to lower sections of East River of the Heihe River show a decreasing trend,but the total amount of SIC is still greater than SOC.This suggests that inorganic carbon predominates in the lower reaches of inland rivers in arid regions.(3)Soil physical and chemical properties showed a stronger explanatory power for SOC,whereas their influence on SIC was comparatively lower.Specifically,soil chemical properties such as elec-trical conductivity(EC),sodium ion(Na+),sulfate(SO42-),chloride ion(Cl-),calcium ion(Ca2+),magnesium ion(Mg2+),and potassium ion(K+)had the most significant influence on SOC.In conclusion,the soil carbon pool in desert riparian forests in the lower reaches of inland river basins in arid areas is predominantly composed of SIC,with notable spatial variations in both horizontal and vertical directions.Basic cations are identified as the prima-ry factor influencing SOC spatial differentiation,while soil sand content and bulk density are the key factors af-fecting SIC spatial differentiation.
riparian Populus euphratica Oliv.forestsoil carbondistribution characteristicsinfluencing fac-torHeihe River Basin
万方数据
维普
