杨树是我国北方营造速生丰产林的主要树种。目前各地的杨树速生丰产林,都是人工整地,栽植大苗培育起来的。这不仅需要投入大量资金和劳力,而且费工费时,为了缩短营造时间,节省资金与劳力,我们于1980年6月中、下旬在长安林场的皆伐迹地上,用人工促进的方法,实现了天然更新,建立了杨树速生丰产林,试验的结果经过两年观察,获得了成功。一、试验树种试验的树种是香杨(Populus korea-na)大青杨(Populus ussuriensis)。香 Poplar is the main species of fast-growing and high-yield forest in northern China. At present, poplar fast-growing and high-yielding forests are all artificial soil preparation, planting seedlings nurtured. This not only requires a lot of capital and labor, but also requires a lot of labor and time. In order to shorten the construction time and save money and labor, we implemented the method of artificial promotion on the deforestation sites of Chang’an Forest Farm in mid-to-late June 1980 Natural regeneration, the establishment of poplar fast-growing high-yield forest, the test results after two years of observation, was successful. First, the experimental tree species tested Populus korea-na poplar (Populus ussuriensis). Fragrant