Study On The Planting And Effects Of Wind-breaking And Sand-fixation Of Living Salix Gordejevii Barrier In Hunshandake Sandland

Salix gordejevii is a useful dune-fixing plant in Hunshandake sandland. Applying the branches of Salix gordejevii cut in spring and autumn period, using the different cutting length, density, barrier size and setting season, in different part of a dune of Hunshandake sandland, setting technology and effects of wind-breaking and sand-fixation of living Salix gordejevii barrier were studied. The results were as follows:(1)In moving sand with low relief area and smaller wind erodibility, higher survival rate and better growth can be achieved with 50cm long cuttings and density of 10 every meter; and in blowout with serious wind erodibility, 50cm long cuttings and density of 10 every meter should be used.(2)The survival rate of living Salix gordejevii barrier setting in spring was higher than that setting in autumn, the survival rate of cuttings which cut in autumn and storaged in winter is higher remarkably than that cut in spring; growth of sand-barrier set in spring with cuttings that cut in autumn and storaged in winter is obvious to be good to the barrier setting in autumn and spring with cuttings that time.(3)The sequence of growth of the sand-barrier in different part of dune:Leeward slopes > Top of dune > Upside of windward flank > Underside of windward flank.(4)After the Salix gordejevii being planted three years, the ground roughness increased and wind-speed slowed down obviously in the area with sand-barrier. The sequence of the barrier sizes corresponding to the sand fixation effects was: 4m×4m > 6m×6m > 4m > 6m > moving sand. When the wind-speed in field was 7.86m·s-1, the sand moving were only occurred in moving sands and 6m Salix gordejevii sand-barrier area, and had not been observed in other types of sand-barrier areas.(5)After the Salix gordejevii being planted six years, the sandland was fixed. The species of the vegetation increased obviously in the area with sand-barrier, perennial herb and shrub, amount of families and genera of vegetation increased obviously. In the area with sand-barrier, particle size distribution of the top 0～5cm soil had changed, content of coarse sand(1～0.25mm)decreased, content of fine sand(0.25～0.05 mm)increased, content of clay(<0.005mm)and silt(0.05～0.005mm)contents increased, but not great. Organic matter contents in the top 0～5cm soil in the area with sand-barriers were increased, the sequence was: 4m×4m > 4m >6m×6m > 6m > moving sand.