农牧交错区是我国荒漠化最严重的地区,重建裸露沙地的植被是消除风沙灾害和实现可持续发展的必要途径。即便没有人的帮助,这里的植被也应该能逐渐布满裸露沙地,使之固定。这个过程是通过现存植被斑块向裸露沙地的连续扩张实现的,其中起主导作用的是各地适生性蒿类固沙半灌木,如科尔沁沙地的差巴嘎蒿、浑善达克沙地的褐沙蒿、毛乌素等中西部沙地的油蒿。尽管植被可以逐渐布满流动沙地,但干旱少雨、风大沙多的条件限制了植被的自我扩张速度。在植被的扩张过程受到阻碍的关键时刻,如果能得到人的恰当帮助,植被恢复速度将明显加快。人们可以采用封育、飞播或设置沙障等方式加快植被的恢复进程。不管怎样,都必须顺应沙地植被的自然发展规律,有意识地触发和利用乡土蒿类植物向裸露沙地扩张的能力。 The ecotone between agriculture and animal husbandry is the most serious desertification in our country. The reconstruction of vegetation in bare sandy land is the necessary way to eliminate the sandstorm disaster and realize the sustainable development. Even without the help of people, the vegetation here should gradually be covered with bare sand to make it fixed. This process is achieved through the continuous expansion of existing vegetative patches to bare sandy areas, dominated by the succession of the adaptive half-shrubs of Artemisia, such as Artemisia halodendron, Horqin sandy land and Hunshandake sandy land Brown sand Artemisia, Mu Us and other midwestern sand Artemisia. Although the vegetation can be gradually covered with mobile sandy land, the conditions of drought and rainy weather and windy sand have limited the rate of vegetation self-expansion. At the crucial moment when the vegetation expansion is hindered, the recovery rate of vegetation will be significantly accelerated if it can be properly assisted by people. One can speed up the process of vegetation restoration by sealing, flying, or setting sand barriers. In any case, it is necessary to comply with the law of the natural development of sandy vegetation and consciously trigger and utilize the ability of native Artemisia species to expand into the bare sandy land.