Survey and structural characteristics analysis of street trees in Tibet

Abstract:

To find out the resources, status, and characteristics of street trees in Tibet, the diversity index, structural characteristics, configuration patterns, ect were analyzed based on the survey of street trees in Tibet. The results showed that:1) There are 63 species of street trees in Tibet, belonging to 36 genera and 20 families, and their average DBH, crown, and height are 12.32cm, 7.21m, 3.90m, respectively. In general, their specifications are obviously small. Among all street trees, Salicaceae is the most applied one, including 15 species; Rosaceae and Pinaceae are the second and third most, including 13, 7 species respectively. 2)The key tree species of street trees in Tibet are Salix alba, Populus × beijingensis, Prunus cerasifera f. atropurpurea, Ulmus pumila and Cedrus deodara. In terms of importance value of street trees, the top three are Salix alba (47.830), Populus × beijingensis (43.459), and Prunus cerasifera f. atropurpurea (22.834) and the diversity index is high. 3) Taking account of seasonal phenomena structure, the street trees display mainly spring-autumn aspection and autumn aspection. In terms of the color trees, they are mainly yellow and white. 4) By the vertically layered structure, it is mainly one layer mode（43.93%）. The structure of street trees in Tibet are undeveloped and lack of flowering shrubs, flowers and ground cover plants.