１９７７年以来在北京市顺义县潮白河沿河沙地进行了沙兰杨、意大利２１４杨、群众杨和加杨等４种杨树的造林对比试验研究。其结果表明，树种间的生长表现有明显差异，沙兰杨和意大利２１４杨的平均高为２４１～２５４ｍ，平均胸径３２５～３３２ｃｍ；林分蓄积量为２４３３５～２５４３６ｍ３，比群众杨和加杨提高约２倍。试验内容还包括土壤水分动态、土壤有机质和元素含量，林木各组分的元素含量以及物候观测等。 Since 1977, comparative studies have been conducted on the afforestation of four poplar species, Populus salina, Populus euphratica, Populus euphratica, poplar and Poplar in Shunyi, Beijing. The results showed that there was a significant difference in the growth performance among species. The average height of Populus tomentosa and Italian 214 Poplars was 241 ~ 254m with the average diameter of 325 ~ 332cm. The stand volume was 24335 ~ 25436m3, which is about two times higher than that of Yang and Yang. The test also includes soil moisture dynamics, soil organic matter and elemental content, elemental content of tree components and phenological observations.