白榆是我国分布范围较广的速生用材树种。由于分布区内自然条件不同,白榆在长期的系统发育过程中形成了不同的地理种源。根据马国骅等同志对白榆种源研究,把白榆分布区划分为三大种源区和六个种源亚区即南部区:1、江淮平原种源区以霍邱种源为代表;2、黄淮平原以杞县种源为代表;中部区:1、华北平原种源区以北京种源为代表;2、黄土高 Ulmus is widely distributed in China’s growing species of timber. Due to the different natural conditions in the distribution area, Ulmus pumila in the long-term phylogenetic process formed a different geographical provenance. According to the research on the provenance of Ulmus pumila, by Ma Guohua and other comrades, the distribution area of ​​Ulmus pumila was divided into three provenance areas and six provenance subregions, namely, the southern area: 1, the provenance of Huaihe River in the JAC plain represented by Huoqiu provenance; The Huang-Huai Plain is represented by the provenance of Qi County. The middle of the area: 1. The provenance of the North China Plain is represented by Beijing provenance;