It's also a part of city planning, take for example Canberra Australia (the capital city), except for the more recent sections of the city (which seems to be su

It's also a part of city planning, take for example Canberra Australia (the capital city), except for the more recent sections of the city (which seems to be suburban sprawls) almost the entire city is tree covered. Certain areas with high rise and high density don't have room for trees.