Abstract:
Objective The winter landscape quality evaluation model of tree species was established to select excellent winter landscape tree species, which provides scientific basis for the selection of them in North China.
Method According to the biological characteristics of tree ornamental organs (tree shape, stem, fruit, leaf and bud), 312 tree species and 455 shrub species of North China were classified and sorted from Arboriculture of North China, 1600 Species of Garden Trees and related literatures. The indices affectingwinter landscape quality of tree species were collected and the comprehensive evaluation model of winter landscape quality of tree species was established by principal component analysis method.
Result Among the excellent tree species selected, there were 12 evergreen tree species belonging to 7 genera and 3 families, and 43 deciduous tree species belonging to 26 genera and 20 families. The results showed that the Salix alba var. pyramidalis was the best with the relative comprehensive index of 0.450 3%. In the second grade, there were 15 evergreen tree species belonging to 4 families and 10 genera, and 94 deciduous tree species belonging to 26 families and 38 genera. Among the excellent shrub species, there were 23 species belonging to 10 genera and 8 families, and 58 species belonging to 23 genera and 15 families. Among them, the ornamental value of Cornus alba was the highest with the relative comprehensive index of 0.362 5%. In the second grade, there were 8 evergreen shrubs belonging to 6 genera and 5 families, and 110 deciduous shrubs belonging to 49 genera and 24 families.
Conclusion The selected trees and shrubs of grade I and II can be used as excellent and good greening tree species for winter landscape quality improvement. Various areas in North China can choose suitable tree species according to site conditions, and improve the winter plant landscape.