I’m not sure what’s underneath the porous surface, but in areas that are otherwise inhospitable to plant life (too much concrete, or lots of salt in the winter), putting the cork/rubbery material over the root ball actually protects the tree from various types of damage, while letting in the water it needs to survive.
Granted, we can easily agree this is a far cry from the beauty of trees found in nature, with gnarly wild roots within a thriving ecosystem and containing a micro-system of its own. No argument from me there!
I’d still rather there be trees planted along a city block, than not 🌱
My two sats 🤝