【摘要】 通过对陇中黄土高原5种典型土地利用方式土壤理化性状、土壤有机、无机碳含量和碳酸盐的δ13C值的分析表明,(1)荒漠草原开垦、栽植人工林后,土壤砂粒含量减少、粉粒增加,以荒漠草原开垦变化显著;pH值降低,以荒漠草原栽植人工林变化显著;电导率均显著降低。退耕还草、弃耕后砂粒含量增加、粉粒减少,pH值升高,均以耕地弃耕后变化显著;退耕还草后电导率显著降低。(2)荒漠草原开垦、退耕还草、弃耕后0~100 cm土壤有机碳含量增加,天然植被栽植人工林后土壤有机碳降低,其中,退耕还草引起土壤有机碳显著变化。(3)荒漠草原转变为人工林、耕地后1 m深土壤无机碳含量显著下降,而耕地弃耕或退耕还草后土壤无机碳的下降未达到显著水平。土地利用类型之间土壤无机碳含量的垂直分布、碳稳定同位素也存在一定差异。更多还原

【Abstract】 The soil organic carbon,soil inorganic carbon contents and the δ13C values of carbonates at the arable land(AL),artificial grassland(AG),artificial woodland(AW),abandoned arable land(AAL) and desert grassland(DG) were analyzed in the Longzhong part of Loess Plateau in Northwest China.The results showed that from DG to AL or AW,the sand contents decreased and silt increased,and the variations were significant in the former conversion;soil pH decreased,being significantly different in the latter;land use conversion and electrical conductivity(EC) were both decreased significantly.From AL to AG or AAL,the sand content increased,silt decreased and pH increased.These changes were significant from AL to AG.The EC also decreased significantly from AL to AG.The conversions from DG to AL,AL to AG and AL to AAL increased soil organic carbon contents at 0-100 cm depth,and the soil organic carbon contents decreased after the conversion of DG to AW.These differences were significant between DG and AL and between AL and AG.The soil inorganic carbon contents at 0-100 cm depth decreased significantly from DG to AW and AL,while the decline was not significant from AL to AAL and AG.Profile distribution and the δ13C values of soil carbonate contents differed among different types of land use to some extent.更多还原