Since When Have Trees Existed Only for Rich Americans?
nytimes.com
nytimes.com
There is a saying 'society grows great when old men plant trees under whose shade they'll never sit'. Such long-term thinking has been shown to create wealth. Like money, trees take a long time to grow to full size and experience exponential growth (at least until they reach some terminalish size).
We ought to expect that those who plant trees have those traits which make them money in the long run, which -- contrary to popular belief -- is how most 'rich' people end up acquiring money. Boring, long-term investing, in trees and money.
Either way, fixing the problem by fixing the appearance is unlikely to change the problem.
In my neighborhood, the trees (which are absolutely giant, given this is the PNW) are in people's yards and sidewalk medians. Above my house, my neighbors tree shades most of the roof and my backyard. Her tree spans almost three lots. My neighbor to my diagonal back has a similarly sized trees. Such trees take a lot of long term care. Looking at pictures of my neighbors tree, when she purchased the house twenty years ago, the tree was very small. Now it is huge.
In the poorer neighborhoods, the yards are not as well kept and are filled with cars. Trees get cut down because people deface them, drive into them (yes, they do), or don't tend to them (granted, it's expensive to hire an arborist to keep your insurance happy).
I saw this growing up in my lower middle class neighborhood in socal. Even though trees are more difficult to grow there, my family invested in our garden so we had more.
It takes long term effort and care to keep a nice garden. The same traits that lead to wealth. My parents sold their lower middle class house and purchased a home with many many trees on a hill.
It's personality and long term thinking
I asked how much to trim a tree in my front yard, was told it was the same price (several hundred dollars) to trim it or to just cut it down and remove it.
Trees are also generally seen as desirable. That desirability directly translates to increases in the value of the home, which prices out the poor. A similar effect would be seen in apartments; the trees require maintenance, maintenance takes money, so apartments with a lot of greenery are going to cost more to live in.
The poor are also more likely to live in housing that they don't own. Why would a rational person dump a bunch of their own money into improving a rental property they don't own? That's assuming that their lease would even allow them to do so.