不同退化程度高寒草地土壤微生物量碳特征分析

为了探讨不同退化程度高寒草地土壤微生物量碳分布变化规律,在具有典型退化特征的高寒草甸与高寒草原研究样地开展野外调查,采集土壤样品,进行室内土壤微生物量碳等指标的测定。结果表明,不同退化程度草地间土壤微生物量碳含量达极显著差异(P0.01),土壤微生物量碳含量随高寒草地退化加剧呈降低趋势,高寒草甸草地与高寒草原草地土壤微生物量碳含量在轻度至极度退化程度下存在极显著差异(P0.01),高寒草甸草地土壤微生物量碳含量为249.18~359.32mg/kg、高寒草原草地为243.11~326.44mg/kg。各退化程度下,土壤微生物量碳不同土层间均达极显著差异(P0.01),呈0~10cm10~20cm20~30cm的变化趋势,土壤微生物量碳含量0~10cm土层较20~30cm下降速度更快,高寒草甸草地各土层微生物量碳含量均高于高寒草原草地。高寒生态条件下,草地退化对土壤微生物量碳具有较为明显的影响。

Characteristics Analysis of Soil Microbial Biomass Carbon on Degradated Alpine Grasslands

To study the distribution and changes of soil microbial biomass carbon on alpine grassland with different degradation degree, we carried out field investigation, collecting soil samples and measuring soil microbial biomass carbon indicators on typical alpine grassland and alpine meadow with typical degradation characteristics. The results showed that soil microbial biomass carbon contents had extremely significant differences between different deteriorated grasslands (P<0.01). Soil microbial biomass carbon contents decreased with degradation degree aggravation on the alpine grassland. Soil microbial biomass carbon contents had extremely significant differences between lightly degradation and extreme degradation on alpine meadow and alpine grassland (P<0.01). The range of alpine meadow soil microbial biomass carbon contents was 249.18-359.32 mg/kg, and alpine grassland was 243.11-326.44 mg/kg.Soil microbial biomass carbon contents had extremely significant difference between different soil layers (P<0.01) in all degraded meadow, and soil microbial biomass carbon contents decreased with the soil depth increase. Soil microbial biomass carbon contents of 0-10 cm reduced faster than 20-30 cm. Soil microbial biomass carbon contents of alpine meadow were higher than that of alpine grassland. Grassland degradation had significant effects on soil microbial biomass carbon on alpine ecological conditions.