Floristics of Landscape Trees from Built-up Area of Tongren City

Investigations were conducted from May to September of 2016 on landscape trees at built-up area of Tongrencity, Guizhouprovince. The result showed that there were 191 species (including subspecies, varieties and variations, excluding cultivar and hybrids) belonging to 68 families and 131 genera. Ratio of genusand species was 68.59%. There were 72 species of native plants belonging to43 families and 67 genera, 119 species of exotic plants belonging to 50 genera and 79 families. The exotic species had 1.65 time thannative one, indicating typical characteristics of artificial and urbanization.Tree species richness and diversity at the built-up area inTongrenwas moderate compared with that in other cities with similar latitude. Geographical composition of genera in the city showed more temperate component than tropical one, indicating that more exotic plants.