草原退化与恢复过程中土壤有机矿质复合体分组研究

对采自处于不同发展方向和阶段的草原土壤分组提取有机矿质复合体，并对它的质量分数、腐殖质质量分数和组成、Ｃ／Ｎ比值等的变化做了分析，试图从土壤复合体变化的角度去认识草原的退化和恢复过程。研究发现土壤腐殖质绝大部分集中于粘粒和粉粒级复合体；退化草原恢复时，复合体腐殖质质量分数增加，并且组成也发生变化；而草原轻度退化时，复合体腐殖质质量分数会减少，但组成不会变化。

Fractional Study of Soil Organo-mineral Complexes in Process of Grassland Degradation and Recovery

Organo-mineral complexes were separated from different developing direction and phases of steppe soils with fractional method of particle-size and density, and their mounts, humus contents, composition and ratio of carbon to nitrogen were analyzed. It aimed to understand the processes of grassland degradation and recovery from variations of complexes. Studies showed that most of soil humus is enriched in clay and silt complexes. When degraded grassland recovers, humus contents of complexes increases and their composition changes. But when grassland slightly degrades, humus contents decreases and their composition does not change.