杨树是我国北方平原地区主要栽培树种,无论成片造林或四旁植树农田林网,杨树造林密度普遍过大,是这些地区大量形成“小老树”,成林不成材的主要原因之一。除泡桐以外,其他树种造林密度也普遍过密。因此,对中幼龄林进行间伐移稀,开展以改革密度为中心的栽培技术革命是当前发展杨树刻不容缓的任务。通过对华北中原的调查及有关单位提供调查材料,对平原地区杨树造林密度进行分析与讨论。历史的教训 Poplar is the main cultivated tree species in the northern plains of our country. Regardless of the afforestation or planting of farmland around the forest net, poplar density is generally too large, which is one of the main reasons for the formation of “little old trees” in large numbers in these areas. . In addition to Paulownia, the afforestation density of other species are generally too close. Therefore, it is an imperative task to poplar cultivation at present to carry out the thinning and thinning of young and middle-aged forests and to carry out the cultivation technology revolution centered on the reform density. Through the investigation of the Central Plains in North China and the investigation materials provided by the relevant units, the density of poplar planting in plain areas is analyzed and discussed. History lesson