念青唐古拉山东南坡高寒草原生态系统表层土壤活性有机碳的影响因素研究

高寒草原是青藏高原广泛分布的植被类型。本文以念青唐古拉山东南坡高寒草原生态系统为对象,采用野外调查与室内分析相结合的方法,对影响高寒草原生态系统表层(0~20cm)土壤活性有机碳分布的因素进行了研究。结果表明:念青唐古拉山东南坡高寒草原生态系统表层(0~20cm)土壤活性有机碳平均含量为2.61±0.31g·kg?1;影响表层土壤活性有机碳分布的地形因子是海拔和坡度,植被因子是0~10cm、10~20cm土层地下生物量,物理因子是0~10cm、10~20cm土壤含水量和0~20cm土壤容重,化学因子是土壤全钾含量。其中0~10cm、10~20cm土壤含水量和0~20cm土壤容重影响达显著水平。在海拔4421~4598m范围内,随着海拔升高,表层土壤活性有机碳含量表现出增加→减少→增加→减少的分布特征。

Influencing factors of topsoil labile organic carbon in alpine grassland ecosystem on the southeast slope of Mountain Nyenquentanglha

Alpine grassland is a widely distributed vegetation type across the Qinghai-Tibet plateau. In this paper, we studied the influencing factors of topsoil labile organic carbon in alpine grassland ecosystem on the southeast slope of Mountain Nyenquentanglha via field investigation and laboratory analysis. Based on the study, average topsoil (0～20 cm) labile organic carbon content in the alpine grassland ecosystem on the studied area is 2.61 ±0.31 g·kg~(-1). The main factors influencing distribution of soil labile organic carbon are altitude and slope gradient (terrain factor), underground soil biomass in the 0～10 cm and 10～20 cm depths (vegetation factor), soil moisture of the 0～10 cm and 10～20 cm depths and soil bulk density of 0～20 cm depth (physical factor), and soil total K content (chemical factor). Soil moisture and bulk density present most significant influence. The distribution characteristics of topsoil labile organic carbon content is in increase-decrease-increase-decrease tendency with altitude in the range of 4 421～4 598 m.