Abstract: To explore the characteristics of soil moisture heterogeneity in sand-fixing artificial vegetation area is of significance in vegetation recovery and environment control in arid regions.With the methods of traditional statistics and geo-statistics,this paper studied the heterogeneity of soil moisture in the layers from 0 to 200 cm in depth in Shapotou sand-fixing vegetation area.The results showed that the variation of soil moisture in layers of 160～180 and 180～200 cm was relatively larger,with the variation coefficient being 072 and 0.73,respectively,and the next was in top layer (0～5 cm ),with a variation coefficient of 0.66.Semi-variance analysis showed that the autocorrelation of soil moisture spatial heterogeneity in total spatial heterogeneity was high,ranging from 87.7% to 99.9%.The scale of spatial heterogeneity in different soil layers was different,with the minimum in 60～80 cm layer and the maximum in 20～40 cm layer,but no regular changes being observed from surface to deep layers.The colorful contour maps of Kriging interpolation indicated that the variation of soil moisture was larger in 0 ～140 cm layer than in 140～200 cm layer.The correlation between semi-variance and distance in four directions of 0°,45°,90° and 135° was weak, suggesting that the variation of soil moisture was independent, random, and homogeneous.

Key words: Haloalkane dehalogenase gene (dhlA), A rabidopsis thaliana, Trans-inactivation, Post-transcriptional silencing