Spatial heterogeneity of soil organic carbon and nitrogen under Ammopiptanhus mongolicus community in arid desert zone
沙冬青群落土壤有机碳和全氮含量的空间异质性

Based on the principles of geo-statistics, this paper studied the spatial heterogeneity of soil organic carbon (SOC) and total nitrogen (TN) under Ammopiptanhus mongolicus community in arid desert zone. The results showed that the mean contents of SOC and TN at the depth of 0 - 5 cm were 0.744 and 0.259 g x kg(-1), with the co-variation coefficient being 0.280 and 0.213, and those at the depth of 50 - 70 cm were 1.425 g x kg(-1) and 0. 295 g x kg(-1), with the co-variation coefficient being 0.195 and 0.206, respectively, reflecting the oligotrophic condition of soil fertility at this habitat. The self-correlation factors resulted in the high spatial heterogeneity of SOC and TN. The dimensions of SOC and TN were 20.99 m and 29.19 m at the depth of 0 - 5 cm, and 42.9 m and 62. 1 m at the depth of 50 - 70 cm, respectively. The dimensions were beyond the confine of canopy and interspace of shrub, without the efficacy of "islands of fertility", which would block the intrusion of other plant species, and support the A. mongolicus shrub live at this habitat. These distribution pattern and dimension of SOC and TN can interprete the long-term living mechanism of A. mongolicus, and supply some theoretical bases for protecting and moving this relic species.