Heterogeneity and differentiation of the tree flora in three major land uses in Guangzhou City, China

The tree flora of humid-tropical Guangzhou city in south China was studied to understand its composition and variations. Aerial photographs identified three major urban-forest types in three land uses: institutional, park and roadside. Data on 115 064 trees in 246 species were statistically analyzed. Park and roadside areas have lower species richness than institutional forest. Park habitat has relatively more rooms for species, biomass and floral enrichment. Roadside leads in tree density with full utilization of plantable space, whereas institutional forest has the highest species density index and the most rare natives. Commonality of species amongst forests limits to 91 species, with park and institutional sharing 68 species, and road sharing merely 8 and 1 species respectively with institutional and park. Institutional forest has distinct composition and character, with less domination by popular species and more solitary or rare species. Native species exceed exotics at roadside; institutional and park have a reverse trend. Practical implications for urban-forest management are discussed.published_or_final_versio