白榆(Ulmus pumila L.)分布在我同长江以北的广大区域内,栽培历史悠久。它适应性强、速生、材质优良,经济价值高,不仅被用作“四旁”绿化,而且也是用材林、防护林和轻盐碱地的主要造林树种。为了探讨白榆地理种源间的生长差异,为我区选择最佳种源和种子调拨区提供科学依据,我们于1979年参加了全国白榆种源试验协作。现将雁北区五年的试验结果总结如下: White Ulmus (Ulmus pumila L.) is distributed in a vast area north of the Yangtze River with a long history of cultivation. It is adaptable, fast-growing, of good quality and of high economic value. It is not only used for afforestation on the “four sides”, but also the main afforestation species of timber forests, shelterbelts and light saline soils. In order to explore the differences in the geographical germplasm resources of Ulmus pumila and to provide the scientific basis for selecting the best provenance and seed allocation areas in our province, we participated in the national elm provenance trial collaboration in 1979. Now Yanbei five years of test results are summarized as follows: