Discussion On Ecological Benefits Of Ulmus Pumila L.var.sabulosa J.H.Guo Y.S.Li Et J.H.Li Woodland In Hunshandake Sandy Land

Ulmus pumila L. var. sabulosa is an indigenous plant in Hunshandake sandy land. Ecological benefits of U. pumila L. var. sabulosa woodland were discussed in four aspects which were effects on wind speed,microclimate,soil nutrients and plant species diversity. The results are as follows: Wind speed was decreased sharply in U. pumila L. var. sabulosa woodland. In the height of 200cm, its effect on wind speed was greater than that of Artemisia intramongolica brush or Salix gordejevii brush. But effect on wind speed of Artemisia intramongolica brush was greater than U. pumila L. var. sabulosa woodland in the height of 50cm. Microclimate was improved obviously in U. pumila L. var. sabulosa woodland. In the woodland, the diurnal variations of atmospheric temperature,relative humidity and soil temperature of 0～20cm were smaller, and the vibration ranges and peak values were smaller than control plots. In summer, atmospheric temperature of the woodland was lower distinctly than that of drifting sandy dunes. However, the differences of atmospheric temperature among Artemisia intramongolica brush,Salix gordejevii brush and degenerated grassland were not distinct. Relative humidity was increased evidently and shallow soil temperature was decreased sharply in the woodland. Compared Artemisia intramongolica brush or Salix gordejevii brush, content of soil nutrients in the woodland was larger. But content of organic matter and total nitrogen in the woodland was inferior to that in degenerated grassland. There were rich plant species that had adapted to conditions of sandy land in U. pumila L. var. sabulosa woodland. Plant species diversity of the woodland community was higher than control communities, and its community structure was complicated. Therefore, the woodland community was stable. Thus, U. pumila L. var. sabulosa woodland could improve evidently ecological environment.