Research on the Introduction Value of Hybrid Tulip Trees in Yangling Area

The introduction value of hybrid tulip trees was comparatively analyzed by observing the growth status, the ornamental properties, and the health condition of 15yearold hybrid tulip trees growing in Yangling area, Shaanxi Province. All the indices of the hybrid tulip trees were compared with those of the same aged and commonly planted buckeye and goldenrain tree species in this area. The results showed that the hybrid tulip trees could grow healthily without any special protection measures, the trees were not suffered from severe diseases, insect pests, frost crack or sunburn. The DBH value and height growth rates of the hybrid tulip trees were much higher than those of the controls. The comprehensive assessments with trunk form, crown traits, branch form, leave form, fruit shape, overall growth consistency and air pollution resistance among the hybrid tulip trees, the buckeye and goldenrain trees showed that the highest score was obtained by the hybrid tulip tree species. Therefore, it was recommended that the hybrid tulip trees could be appropriately extended to be planted both in the local area for urban and rural greening and afforestation.