One of the major points in Charles Mann’s 1491 (great book, a fave) is that the indigenous peoples of the Americas did not live in pristine wilderness. Through techniques like cultivation and controlled burning, they profoundly shaped their environments, from the forests of New England to the Amazon.
In the 1850s, the indigenous inhabitants of Yosemite Valley, who used controlled burning to maintain the health of the forest, were driven out by a militia. As Eric Michael Johnson writes in Scientific American, the belief in the myth of pristine wilderness by naturalist John Muir has had a negative impact on the biodiversity and the ability to prevent catastrophic fire damage in Yosemite National Park.
The results of this analysis were statistically significant (p < 0.01) and revealed that shade-tolerant species such as White fir and incense cedar had increased to such an extent that Yosemite Valley was now two times more densely packed than it had been in the nineteenth century. These smaller and more flammable trees had pushed out the shade-intolerant species, such as oak or pine, and reduced their numbers by half. After a century of fire suppression in the Yosemite Valley biodiversity had actually declined, trees were now 20 percent smaller, and the forest was more vulnerable to catastrophic fires than it had been before the U.S. Army and armed vigilantes expelled the native population.
(via @charlescmann)