1st Nations people have been doing that sort of thing all over.
The grasslands were regularly burned to encourgae buffalo to come when the new growth sprouted after the fires, this helped stop the grasslands from slowly being turned into woodland like they would have been if not for human intervention.
The American East coast
Natives managed the forests, again often using fire to burn undergrowth.
Around the world this sort of story of tribal natives being active stewards of the
land and playing very important roles in managing the environment around them can be found. From preserving certain types of ecosystems through intervention in natural secession to planting certain types of plants and tress to help spread desired growth, humans have and can be positive actors upon the planet.
"Where will you drive your own picket stake? Where will you choose to make your stand? Give me a threshold, a specific point at which you will finally stop running, at which you will finally fight back." (Derrick Jensen)