毛乌素沙地不同防风材料降低风速效应的比较

在干旱半干旱区植被生态建设过程中 ,需要进行决策并经常引起争论的问题是 ,应该选择哪种类型植被 ,才能获得最大的防风效应。为比较不同防风材料降低风速效应的差异 ,在春季大风天气 ,选取毛乌素沙地 5种常见的灌草乔植物和 2种常见的人工防风材料栅格沙障和栅栏 ,进行防风性能野外实地观测。分析结果表明 ,几种防风材料降低风速性能从大到小的次序为 :沙蒿 >芨芨草 >杨柴和牛心朴子 >沙障 >栅栏 >旱柳 ,沙蒿性能最好 ,降低风速比率达到 0 .49,旱柳性能最差 ,近似为 0 ;就乔、灌、草植被类型而言 ,防风效应的一般次序为 :灌木 >草本 >乔木。据此认为 ,干旱半干旱区植被生态建设中 ,坚持以灌木和草本植物为主的原则 ,才能提高有效水资源的利用效率 ,取得较好的环保效益。

Comparison of WindVelocity Reduced by Seven Different Windproof Materials in Maowusu Sandland

What type vegetation should be chosen in the process of vegetation construction in arid and semi arid regions is an inevitable and often disputable topic. Five kinds of plant and two kinds of artificial windproof materials were used to observe on the difference of capacity of reducing wind velocity in windy days in the spring. Result shows that the order of these materials on reducing wind velocity is Artemisia ordosica>Achnatherum splendens>Hedysarum mongolicum andPycnostelma lateriflorm>grid sand obstacle>split rail>Salix matsudana. The ratio of wind velocity reduced by Artemisia ordosica is the biggest which reaches almost 50% and Salix matsudana is the smallest almost equal zero. As regard to the three life form type of windproof materials tree, shrub and grass, the order is shrub>grass>tree. By this, the conclusion that shrub and grass vegetation should take a preferential place in vegetation construction of arid and semi arid regions.