若尔盖高原湿地生态恢复过程中土壤有机质的变化研究

Study on Change of Soil Organic Matter in the Process of Wetland Ecological Restoration in Ruoergai Plateau

采用野外调查和室内分析结合的方法研究了若尔盖高原湿地生态恢复过程中土壤有机质的数量、分布及质量变化 ,以探讨生态恢复过程对湿地土壤肥力的影响。结果表明 ,在若尔盖高原湿地生态恢复过程中 ,土壤类型发生相应的生态演替 ,其恢复演替序列为风沙土→草甸土→沼泽土→泥炭土。随着湿地生态系统的逐步恢复 ,土壤有机质的含量大幅度提高 ,土壤有机碳的氧化稳定性趋于增强 ,土壤腐殖质组成中胡敏酸的含量逐步提高 ,胡敏酸的E4值增大 ,E4/E6值减小 ,土壤腐殖质的品质改善。土壤有机质的数量、分布及质量变化均表现出与湿地生态条件和环境变化的高度一致性 。

The change of quantity, quality and distribution, of soil organic matter in the process of wetland ecological restoration was studied with field investigation and laboratorial analysis and the effect of ecological restoration on soil fertility in Ruoergai Plateau was expored. The results indicated that there was an ecological succession of wetland soil types and their restoration successive series showed aeolian sandy soil→meadow soil→bog soil→peat soil in the process of wetland ecological restoration. With the restoration of wetland ecosystem, the amount of soil organic carbon increased greatly and distribution characteristic of soil organic matter on profile showed surface layer (0-20cm)>subhorizon (20-40cm)>ground layer (40-60cm), the order of oxidation stability coefficient of soil organic matter was peat soil>bog soil>meadow soil>aeolian sandy soil and the oxidation stability of soil organic matter was enhanced. In the restoration successive series of aeolian sandy soil→meadow soil→bog soil→peat soil, the content of soil humic acid (HA) and E4 value of HA increased while E4/E6 value of HA decreased, the conent order of total acid group, carboxyl group and hydroxyl group was also peat soil>bog soil>meadow soil>aeolian sandy soil, the quality of soil humus improved. There was a high coordination between change of the quantity, distribution and quality of soil organic matter and wetland ecological environment in Ruoergai Plateau, wetland ecological restoration was helpful to the improvement of soil fertility.