青藏高原土壤有机碳密度垂直分布研究

Study on the vertical distribution of soil organic carbon density in the Tibetan Plateau

通过对青藏高原土壤普查数据的整理分析，定量研究了青藏高原28个典型土壤类型、14个主要生态系统类型0～20cm、20～50cm及50～100cm深度内土壤有机碳密度的垂直分布规律，结果表明，青藏高原28个典型土壤类型3个土层的有机碳密度平均值为（6.16±1.08）kg·m^-2、（5.06±0.85）kg·m^-2、（5.30±0.82）kg·m^-2；在0～100cm土层内，暗棕壤、沼泽土的有机碳密度显著高于其它土壤类型，而高山漠土、灰棕漠土、亚高山漠土的有机碳密度不仅远远低于区域平均水平，而且显著低于其它土壤类型，14个典型生态系统土壤的有机碳密度均值为（7.47±1.38）kg·m^-2、（6.07±1.24）kg·m^-2、（6.46±1.16）kg·m^-2；其中，以沼泽草甸、针叶林土壤的有机碳密度最高，而温性荒漠、高寒荒漠、高寒草原及亚高山草原土壤有机碳密度显著低于其它生态系统，这不仅体现了青藏高原土壤-植被显著的地带性分布，而且为青藏高原土壤有机碳循环模型，及有机碳对全球变化的响应研究提供重要的基础数据。

Soil organic carbon, particularly high altitude soils, may have important effects on the global carbon cycle and global warming. A quantitative study on Tibetan Plateau soils was carried out to determine the vertical distribution of soil organic carbon density in three layers （0-20 cm, 20-50 cm and 50-100 cm） of 28 soils and 14 ecosystem types. The average soil organic carbon densities in the three layers were （6.16±1.08） kg·m^-2, （5.06±0.85 ） kg·m^-2, and （5.30±0.82） kg·m^-2 The soil organic carbon density of dark brown earth and bog soil were highest in the 0-100 cm deptb of soil among 28 soil types, while the carbon density of alpine desert soil and subalpine desert soil were significantly lower than the others. The average soil organic carbon density in the three layers among 14 ecosystems were （7.47±1.38） kg·m^-2,（6.07±1.24） kg·m^-2,and （6.46± 1.16）kg·m^-2. The soil organic carbon densities of bog meadow and conifer forest were not only higher than the average level of the study area, but also significantly higher than the others. However, the soil organic carbon density of alpine grassland, subalpine grassland, teruperate desert and alpine desert were about 3.0 kg·m^-2, significantly lower than the other ecosystems. This study not only indicated that soil organic carbon density in the Tibetan Plateau varied significantly among the 28 typical soil types and 14 ecosystems, but also showed a zonal distribution of ecosystem and the soil in the study area, which could provide information for models of the soil organic carbon cycle, and on the response of soil organic carbon in the Tibetan Plateau to global climate change.