"the trash-strewn lots of Detroit and the subway tunnels of New York support far more biodiversity than the sterile, “sustainably planted” forests that cover most of the continental U.S." – Christopher Mims, in an article at a site called Motherboard.
This seems depressing and darkly pessimistic, but frankly, I find in it cause for optimism. Why? Because that means nature is actually pretty good at building biodiversity "under duress." The world is not ending – merely changing. And evolution is all about adaptation. Things will go on.