Study On The Growth Of Hedysarum Laeve And Soil Characteristic And Sand-fixation In Hunshandak Sandland

Hedysarum laeve is a kind of dune-fixing pioneer shrub in Hunshandak Sandland, China. Hedysarum laeve takes a vital role in improvement of ecological environment . We had conducted a series of explorative research, which included morphological and structural adaptability, sand water content , setting technology of sand barrier and effects of wind-breaking and sand-fixation and so on, with main conclusions being achieved as follows:(1) Growth of Hedysarum laeve over time was significant in high-growth phase. The coarse sandy content and plant height, the new branch length and basal diameter was positively correlated. At the same time, silt particle content and plant height , the new branches growth was significant negative correlation.(2) Lateral roots of Hedysarum laeve grow rapidly in high-growth phase, while main root grow slow.The coarse sandy content and growth of lateral roots, number of lateral roots, crown of lateral roots was positively correlated.(3) In the high-growth phase, sand water content and sand depth was a polynomial linear correlation. Hedysarum laeve roots concentrated in the 20cm ~ 60cm soil layers.(4) The provision of Hedysarum laeve sand barrier in three years, desertification has been managed.Vegetation cover from the previous 5% to about 50%. The degraded grassland plant species increase from 8 kinds to more than 20 species. Plant diversity was improved significantly.(5) Living Hedysarum Laeve Barrier can be significantly reduced wind speed, and wind force weakened. The grid configuration in the reduction of wind speed ratio higher than the strip configuration. Living Hedysarum Laeve Barrier has played a significant role in the sand. When the wind-speed in field was 7.86m·s-1, sand deposition of the non-treatment area was 32.12g in 5 minutes, the field managed area was 1.78g.