一、前言杨树在乌盟分布广,生长快,适应性强,繁殖容易,是乌盟地区主要用材树种之一,也是营造农田防护林、护牧林和城乡绿化的重要树种。遵照毛主席“有了优良品种,即不增加劳动力、肥料,也可获得较多的收成”的伟大教导,全盟各级领导对于杨树良种的选育和管理工作都极为重视,特别是在以华主席为首的党中央,取得了粉碎“四人帮”反党集团和抓纲治国的伟大胜利的鼓午下,全盟林木良种选育工作出现了蓬勃发展的大好形势。近年来全盟在选育和发展乡土树种的同时,从区内、外引进杨树种和杂种系号约220余个,在生产上广泛地应用和繁殖,经过多年的栽培,在不同立地条件下,其生长表现差异很大。为留优去劣,尽快地筛选出乌盟地区不同类型条件生长的杨树良种,做到适地适树,对实现杨树造林良种化,有现实的指导意义。为此,内蒙林研所和乌盟林果研究所组成杨树调查组,于一九七七年七月十二日至八月二十五日对乌盟地区16个旗县的有关林场、社办场圃及四旁绿化等37个点的31个杨树品种进行了实地调查。根据适合发展杨树的立地类型,初步区划了五个自然类型区,选出了十六个杨树良种。二、乌盟地类和杨树概况乌盟地处内蒙古高原,地形复杂,大青山东西横贯,将全盟分为山南山北两个区域,通常称为山南为前山;山北为后山。前山为黄土高原,丘陵起伏、沟壑纵横,并间有高山,平 I. Introduction Poplar in the Uruguay wide distribution, rapid growth, adaptability, easy reproduction, is the Uruguay one of the main timber species, but also to create farmland shelterbelts, forest protection and urban and rural afforestation important species. Following Chairman Mao’s great teachings of “excellent varieties, that is, more harvests can be obtained without increasing labor force and fertilizers,” leaders of all levels at all levels attach great importance to the breeding and management of poplar species, especially at With the Central Committee of the Party led by Chairman Hua and the drums of the luncheon who smashed the “gang of four” anti-party clique and the tremendous victory of the country by governing the country, the vigorous development of tree seed selection and breeding in the alliance has seen a flourishing development. In recent years, the alliance in breeding and development of native tree species at the same time, from the region, the introduction of poplar species and hybrids about 220, widely used in production and breeding, after years of cultivation, in different site conditions Under the growth performance of its very different. In order to retain the superiority, the poplar varieties grown under different types of conditions in the UMN region should be screened out as soon as possible to achieve the suitable planting of trees. This has realistic guiding significance for poplar afforestation. To this end, the Inner Mongolia Institute and Ulleungu Fruit Research Institute composed of poplar investigation team, from July 12 to August 25, 1977 on the Uygur Autonomous Region 16 Banner counties of the relevant forest farms, Field Office and nursery on the green and other 37 points of 31 species of poplar field investigation. According to the site types suitable for the development of poplars, five natural type zones were initially divided into 16 poplar varieties. Second, the UFOs category and poplar profile UF is located in the Inner Mongolia Plateau, complex terrain, Daqing Mountains across the east and west will be divided into two areas Shannan Shan, commonly known as the former Shan Shan; Former Hill Loess Plateau, rolling hills, ravines aspect, and between the mountains, flat