| 1. | 4 . in the process of spontaneous vegetation recovery of blown sand soil , coarse sands ( l - 0 . 25mm ) content gradually lower , middle sands ( 0 . 25 - 0 . 05mm ) and fine sands ( 0 . 05 - 0 . 02mm ) , silt , clay content gradually higher in mechanical composition
4 、在自然植被恢复过程中，风沙土机械组成中砂粒含量变化表现为粗砂含量的降低，中砂和细砂含量的升高，砂粒整体含量降低。 |
