CAJ | 학술논문

封育是当前恢复和改良内蒙古草地的重要措施，也是实现草地固碳效应最有效的途径之一。本文利用内蒙古封育32年和自由放牧的羊草草地，分析了其土壤有机碳组分、土壤团聚体和土壤腐殖质组分碳含量的变化，并运用13 C核磁共振波普法对土壤腐殖质的有机碳组分进行波普分析，探讨了长期封育对羊草草地土壤有机碳组分和土壤有机质结构的影响，期望能为科学地评估长期封育状况下草地固碳效应及其稳定性提供理论依据。实验结果表明：长期封育显著提高了草地土壤有机碳含量；在土壤有机碳组分中，除土壤微生物碳（MBC ）含量降低外，其碳组分含量都相应增加。其中，易氧化有机碳（EOC）含量增加最为明显，长期封育草地是自由放牧草地土壤的4．53倍；长期封育显著提高了草地土壤0．25～2 mm 团聚体所占比例及其有机碳含量；长期封育提高了草地土壤腐殖质中的胡敏酸碳（HAC）、胡敏素碳（HUC）含量和胡敏酸／腐殖质碳，降低了富里酸碳（FAC）的含量，封育草地土壤的 H AC／FAC是自由放牧草地土壤的5．66倍。此外，长期封育草地土壤的脂族碳含量显著增加，芳香度相应增加，疏水碳／亲水碳增大。总之，长期封育不仅提高了草地土壤有机碳贮量，还能改善草地土壤结构、增强土壤有机碳的稳定性。
봉육시당전회복화개량내몽고초지적중요조시，야시실현초지고탄효응최유효적도경지일。본문이용내몽고봉육32년화자유방목적양초초지，분석료기토양유궤탄조분、토양단취체화토양부식질조분탄함량적변화，병운용13 C핵자공진파보법대토양부식질적유궤탄조분진행파보분석，탐토료장기봉육대양초초지토양유궤탄조분화토양유궤질결구적영향，기망능위과학지평고장기봉육상황하초지고탄효응급기은정성제공이론의거。실험결과표명：장기봉육현저제고료초지토양유궤탄함량；재토양유궤탄조분중，제토양미생물탄（MBC ）함량강저외，기탄조분함량도상응증가。기중，역양화유궤탄（EOC）함량증가최위명현，장기봉육초지시자유방목초지토양적4．53배；장기봉육현저제고료초지토양0．25～2 mm 단취체소점비례급기유궤탄함량；장기봉육제고료초지토양부식질중적호민산탄（HAC）、호민소탄（HUC）함량화호민산／부식질탄，강저료부리산탄（FAC）적함량，봉육초지토양적 H AC／FAC시자유방목초지토양적5．66배。차외，장기봉육초지토양적지족탄함량현저증가，방향도상응증가，소수탄／친수탄증대。총지，장기봉육불부제고료초지토양유궤탄저량，환능개선초지토양결구、증강토양유궤탄적은정성。
Grazing exclusion (GE)is an important method for restoring grasslands and a useful approach for un-derstanding soil carbon (C)sequestration in temperate grasslands.Using the paired sample method C in the soil fractions,soil aggregates and soil humus was determined for grazed and ungrazed grassland in Inner Mon-golia,China;grazing exclusion (GE)had been imposed for 32 years in the un-grazed grassland.To reveal the influence of GE on the structure of soil organic matter 13 C-NMR (Nuclear Magnetic Resonance)spectroscopy was used to analyze the organic C fractions in the soil humus.The main objective was to provide a theoretical basis for scientifically evaluating the effect of GE on the sequestration and stability of C in Inner Mongolian grassland soils.The results showed that long-term GE significantly enhanced soil C content.The C content in all other fractions,except for soil microbial biomass C (MBC),increased correspondingly.The oxidizable or-ganic C in the GE grassland was 4.5 times that of grazed grassland.GE significantly improved the proportion of 0.25-2.00 mm diameter macro-aggregates and their organic C content.GE increased humic acid C (HAC), humin C (HUC)and the soil precipitate ratio (PQ),but decreased fulvic acid C (FAC).Consequently,the HAC:FAC ratio in GE grassland was 5.66 times that of grazed grassland.Additionally,aliphatic C content, aromaticity and the alkyl:O-alkyl C ratio increased in the GE grassland.In summary;GE increased soil organ-ic C,improved the soil structure and enhanced the stability of soil organic matter of Inner Mongolian grass-lands .