Just a note, the fire management techniques were employed by indigenous people to mimic how the world already worked with natural fires. Your not wrong in saying it was a technology but it was not the cause of the current situation as they did not practice that tech long enough to impact the ecosystems reliance on it. All the species in that environment already relied oh fires. Small example, sequoia trees who's seeds only germinate after a fire. This evolution occurred millions of years before indigenous peoples where even around. Not to take away from the brilliance of the tech but it was discovered from how the world already worked it did not create a new niche.