Vertical Distribution Law of Roots for Hippophae rhamnoides Community in Soft Sandstone Area

In the soft sandstone area,the weights,lengths,numbers of roots for Hippophae rhamnoides increase sharply in the topsoil and then decrease gradually with the soil depths.Because of the invaded grasses,roots for Hippophae rhamnoides community appear to be well represented by two models of CUBIC INVERSE.Hippophae rhamnoides community roots distribute in the topsoil of 0-50 cm,which is useful not only for absorbing the runoffs to maintain the growth of Hippophae rhamnoides community,but benefiting a lot for the control of erosions of both surface gully to decrease the sedimentation to the rivers.