“…At present there are two typical kinds of definitions for "urban forest": one defines it as the sum of all woody plants and other associated plants in a city which includes its surrounding area (Gobster, 1994;Miller, 1997), while the other definition is the tree community covering a certain area in a city and its suburbs. Research on urban forests started in the 1960's and many cities were selected as the study areas, such as Athens, Greece (Profous, Rowntree, & Loeb, 1988), Hong Kong (Jim, 1992), Prague, Czechoslovakia (Profous & Rowntree, 1993), New York, U. S. (Richards, Mallette, & Simpson, 1984), Oakland, U. S. (Nowak, 1993), Chicago, U. S. (McPherson et al, 1997), Los Angeles, U. S. (Miller & Winer, 1984) and San Francisco, U. S. (McBride & Froehlich, 1984).…”