前言我国北方栽植杨树已有悠久的历史。种类较多,其中乡土树种毛白杨经近年鉴定,仍属优良品种之一,实际也是群众长期喜爱的。随着国家积极营造速生树种发挥其多种效益并开展综合利用,国内对毛白杨有关问题已进行了许多研究,但在树皮方面尚少较系统的报道。“树皮”不是一个技术性的名词,一般泛指木本植物干枝维管形成层以外的所有组织结构物质。在树木生长发育过程中,树皮承担着特有的生理功能,如营养运输、代谢转化、 Foreword planting poplars in northern China has a long history. Many species, of which native species Populus tomentones identified in recent years, is still one of the fine varieties, the actual long-term favorite of the masses. As the state actively creates quick-growing tree species to exert its multiple benefits and carry out comprehensive utilization, many studies have been conducted on the problems related to Populus tomentosa in China. However, there are few systematic reports on bark. “Bark” is not a technical term, generally refers to all the tissue material other than woody plant stems vascular cambium. In the process of tree growth and development, bark bear the unique physiological functions, such as nutrient transport, metabolic transformation,