@fabulousfungi brought up some similar points elsewhere in the comments - and that is the dilemma of even a park like Central Park - they are leaving many trees up with fungi intact - all of the ones in these photos for instance - but because its only a "sort of" ecosystem, i wonder whether that's the right move or not.
Unfortunately for the many street trees around the city, they live in relative isolation and with a lot of physical abuse. I suppose the fact that any of them live several decades is a miracle in the first place.
RE: The Amateur Mycologist Tree Health Special - A Crash Course In Trees, Fungal Infections, And The Ailing Giants Of Central Park