关键词: 铁杆蒿群落, 碳、氮密度, 区域差异, 生态因子

Abstract: In order to explore the spatial variation of C and N density in Artemisia sacrorum communities and to identify the driving factors,this experiment measured the vegetation C and N density of the Artemisia sacrorum communities in semi-arid region of northern Shanxi and semi-humid area of southern Shanxi,and analyzed their correlations with the ecological factors such as average annual temperature,average annual precipitation,soil physical and chemical properties and above-ground and underground biomass. The results indicated that,the spatial distribution of C and N density in Artemisia sacrorum communities was different between northern Shanxi and southern Shanxi. The C and N density of Artemisia sacrorum community were 651.83 C·m^-2 and 20.63 g N·m^-2 respectively in Southern Shanxi,and were 418.89 g C·m^-2 and 13.90 g N·m^-2 respectively in Northern Shanxi. The C density and N density of each component of the community was used as representative sampling points for RDA sequencing. The results showed that the main ecological factors that caused the C and N density differences of the communities in the two regions were aboveground biomass,underground biomass,annual average temperature,annual precipitation,soil organic carbon content and soil gravel ratio. In conclusion,there are differences in the spatial distribution of carbon and nitrogen density between southern Shanxi and northern Shanxi. The spatial differences of carbon and nitrogen density are closely related to the accumulation of biomass in different climatic areas. The environmental factors driving the differentiation of carbon and nitrogen density of Artemisia artemisia communities in southern and northern Shanxi are annual average temperature,annual precipitation,soil organic carbon content and soil gravel ratio.

Key words: Artemisia sacrorum community, C and N density, Spatial variation, Ecological factors