榆树是我区“三北”防护林建设的主要树种之一。在乌兰察布盟后山地区榆树造林面积约占整个造林面积的80％以上。榆树耐低温、耐干旱、耐瘠薄。也比较能抗盐碱,深受广大群众欢迎。但近几年来,后山榆树大面积死亡,部分林场榆树死亡率达80％,给林业生产带来很大损失。为了控制榆树的死亡,我们于1980年6月到10月对七个旗县,二十多个林场的榆树进行了调查和研究。现 Elm is one of the main tree species in the “Three North” shelterbelt in our district. In Wulanchabu League mountainous area of ​​elm afforestation area accounts for about 80% of the entire afforestation area. Elm low temperature, drought resistance, barren. Also more resistant to salt, welcomed by the masses. However, in recent years, large areas of mountain elm trees died, and the mortality rate of elm trees in some tree farms reached 80%, which brought great losses to forestry production. In order to control the death of the elm trees, we surveyed and studied the elm trees in seven flag counties and over twenty forest farms from June to October 1980. Now