| In recent years,the management of mobile sand dunes has become a hot issue.This article through three kinds of sand-fixing plants with different planting densities were planted in different size sand-barrier,the dominant species of afforestation,planting density and the most suitable sand-barrier laying specifications were selected,the research land was chosen in Hobq Desert mobile Dune area,and the suitable specifications of PLA sand-barrier,Reed sand-barrier and Salix sandy barrier were laid,then carry out dominant planting.The effects of different types of sand-barrier on plant survival rate,plant height,crown area,branch number and soil moisture content,organic matter,alkali solution nitrogen,available phosphorus and available potassium content were studied.The most conclusions are as follows:(1)Under the sand-barrier specification of 1m×1m,the Salix trees are planted in 2m×2m density.The survival rate of the plant is highest,the top of slope is 94%,the medium slope and slope bottom are 100%,the height is slope bottom>the medium slope>the top of slope,respectively is 141cm,135cm,133cm,the crown is slope bottom>the medium slope>the top of slope,respectively,101cm×85cm,70cm×69cm,50cm×49cm,The number of branches is the bottom of slope and the top of slope,28cm,22cm and 19cm respectively.(2)The survival rate of three different sand-barrier was 100%higher than that of PLA sand-barrier at the top of slope,Reed sand-barrier is the worst 90%,medium slope and slope bottom are 100%,the height of sand-barrier in the top of the slope is the highest 135cm,the higher than the PLA sand-barrier and Reed Sand-barrier 3cm and18cm,the slope and the bottom of the slope are the highest in the PLA sand-barrier,142cm and 146cm respectively,the lowest in the Reed sand-barrier in the slope is 125cm,the lowest in the bottom of the sand-barrier is 141cm,the Crown amplitude area in different slope position are PLA sand-barrier the largest,respectively,1.16m~2,0.8m~2,0.32m~2,slope top and slope bottom for the reed sand-barrier the smallest,Compared with the maximum value of small 0.16m~2?0.34m~2,slope of the willow sand-barrier the smallest,the number of branches in different slopes is the highest of PLA sand-barrier,respectively,33,29,19,the top of the slope and the bottom of the slope are the reed sand-barrier minimum 17 and 28,and the minimum of 0.32m~2 in the slope is 22(3)The overall trend of water content in 3 different sand-barrier was sand-barrier,Reed Sand-barrier>PLA Sand-barrier,the maximum value was sand-barrier at the bottom of the willow 80-100cm slope,and the water content increased first and then decreased with the increase of soil depth,and the organic content in PLA sand-barrier and Reed sand-barrier was first decreased and then increased.The maximum values were in 0-5cm,respectively,2.00g/kg,1.78g/kg,and Salix sand-barrier,the maximum value in40-60cm was 3.56g/kg;the change tendency of alkali nitrogen content in different sand-barrier was not obvious,but the content was higher than that of bare sand dunes.The overall trend of available content is in slope top and medium slope.At the bottom,PLA sand-barrier,reed Sand-barrier and Willow Sand-barrier,the content of available potassium in PLA sand-barrier and reed Sand-barrier decreased with the depth of soil layer,and the maximum value of PLA sand-barrier appeared in the slope 5-10cm,44.48mg/kg,Salix sand-barrier,the maximum value in the slope 0-5cm were48.47mg/kg.(4)After laying sand-barrier afforestation in mobile dune,can significantly improve the survival rate of plant and preservation,promotion of vegetation growth,under the joint action of sand-barrier and vegetation,significantly improved soil nutrients,fixation of sand dunes. |
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