杨树(Populus)是我国某些地区的速生丰产用材树种之一,它的适应性大,抗逆力强。在我国许多地区进行了引种,其中有些引进树种生长良好。当前,大力发展杨树是实现我国四个现代化对木材需要的一个有效措施。了解杨树叶中秋季营养物质的动态,是制定杨树秋季栽培管理措施的理论依据,也是杨树良种选育的生理基础。材料和方法在本院林学系苗圃,选择生长迅速的杂种杨树——美杨×滇杨+青杨(P.pyramidalis Roz.×p.yunnanensis Dode+P.cathayana Rehd)一年生插条苗木为主要试验材料 Populus is one of the fast growing timber species in some parts of China. Its adaptability and resilience are strong. Many areas in our country were introduced, some of which introduced good growth. At present, the vigorous development of poplar is an effective measure to realize the timber needs of the four modernizations in our country. To understand the dynamics of poplar leaves in autumn nutrients is to develop the theoretical basis for poplar cultivation management measures in autumn, is also the physiological basis for poplar breeding. MATERIALS AND METHODS The annual seedlings of P. pyramidalis Roz. × p.yunnanensis Dode + P..cathayana Rehd were selected as the main hybrid poplars in the nursery of Forestry Department of our hospital. experiment material