Effect of The Mixed Forest of Salix gordejevii and Hedysarum fruticosum var.mongolicum for Fixing The High and Large Sand Dunes

Through studying the growth of Salix gordejevii and Hedysarum fruticosum var. mongolicum,the characteristics of wind erosion sedimentary sand,the plant diversity,surface hardness of moving dune,the influences of the mixed forest of Salix gordejevii and Hedysarum fruticosum var. mongolicum under the protection of biological-mechanical sand barrier on the ecological restoration in moving dune have been researched. The results show that the materials of biological- mechanical sand barrier are in good growth state,and the average survival rate of Salix gordejevii is 60. 35%,the average survival rate of Hedysarum fruticosum var. mongolicum in sand barrieris65. 85%. The average height of 4- year Salix gordejevii is 132. 0 cm,and the average height of Hedysarum fruticosum var. mongolicum is 99. 2 cm. The plant species increases from 4- 5 kinds to 7 kinds,and perennials has appeared. The width of blown sand and the wind- erosion depth of surface are significantly increased. The surface hardness has increased obviously,which shows a wave trend along the main wind direction.