山杨Populus davidiana Dode.是我国和东南亚诸国特有的变种。在我国的分布,从黑龙江、内蒙古到华北、西北、西南高山地区均有。其垂直分布可达海拔三千八百米。山杨在国民经济中有着广泛的用途。是绿化祖国的速生树种之一。但山杨易得立木心材病腐,此病为害普遍而严重。据我们调查及文献记载,幼树就染心腐,50年生,发 Populus davidiana Dode. Is endemic to China and Southeast Asia. Distribution in our country, from Heilongjiang, Inner Mongolia to North China, northwest, southwest alpine areas are. Its vertical distribution of up to 3,800 meters above sea level. Aspen has a wide range of uses in the national economy. Is one of the fast-growing tree species afforesting the motherland. But Poplar easy to stand Li heartwood disease rot, the disease is common and serious damage. According to our investigation and documentation, saplings dye heart rot, 50 years old, hair