Maybe there should be some sort of global chaga tax to fund birch reforestation. If a few bucks was added to every Amazon order or whatever then that would at least help out a bit.
That rewards those who can creatively find a way to shop at Amazon despite taxes more so than it rewards those who can creatively plant trees despite every other hurdle to do so.
It can't be cultivated, it just grows wherever there are birch trees. So planting more birch would just mitigate any effects of over harvesting elsewhere, while increasing the global supply.