1981年,以B.克鲁格曼博士为首的美国树种改良考察组到我国一些科研和生产单位做了短期考察,每到一处我们都在参观的基础上组织了双方专家的座谈讨论.现将美国专家沿途根据所见到的情况和我方人员提出的问题做的一些回答,整理如下:一、树种改良方面1.树种选择 除东北地区外,一路看的大都是少数引进树种的改良工作.专家们多次指出,研究重点应放到当地原产树种上,说美国就很少大面积应用引入树种造林,树种改良要从当地树种中选择开始,美国就对国产的近170个树种进行改良,对92个树种建立了种子园.在当地树种中除 In 1981, Dr. B. Krugman led the American Tree Specimen Improvement Team to visit some scientific research and production units in China for a short period of time. Each time we went to visit we organized a panel discussion with experts from both sides. Some suggestions made by U.S. experts along the way and on the issues raised by our staff are summarized as follows: I. Tree species improvement 1. Tree species selection In addition to the Northeast China, most of the improvements along the way are the few introduced tree species Experts have pointed out on many occasions that research should focus on local native tree species, saying that the United States has rarely applied large - scale tree planting and tree improvement should start with the selection of local tree species, and the United States has made nearly 170 tree species domestically made Improved, a seed orchard was established for 92 species, except for native species