Spatial heterogeneity of understory soil physical properties for Picea schrenkiana var. tianschanica in the Tianshan mountains.

Picea schrenkiana var.tianschanica is dominant tree species and constructive species in the Tianshan mountains.In the middle of Tianshan mountains,elevation ranged from 1960～2700 m,the spatial heterogeneity of understory soil physical properties for P.schrenkiana var.tianschanica at 100 m elevation gradient was studied.The results showed that:(1)The soil volume weight increased with the increase of soil depth,however,the total porosity,capillary porosity,noncapillary porosity,water content,saturated moisture capacity,capillary holding capacity and field capacity decreased gradually.(2)In the layer of 0~60 cm,soil volume weight decreased with the increase of elevation from 1960 m to 2300 m.While increased from 2300 m to 2700 m.(3)In the layer of 0~60 cm,total porosity,capillary porosity,capillary holding capacity,saturated moisture capacity and field capacity increased with the rise of elevation from 1960 m to 2300 m,and decreased from 2300 m to 2700 m.but,noncapillary porosity showed little change among all elevations.(4)In the layer of 0~60 cm,natural water content was highest in the 2500 m elevation.