What is the positive human impact on the taiga?

the humans start cutting down trees and that takes away the habitats on animals.

If you accept that humans instigate global warming, then humans can have a big impact on the taiga. In the Tundra, the ground is made up of permafrost - ground that is permanently frozen. As the earth warms, the permafrost thaws. Trees that grow in the tundra can fall over as the permafrost thaws.

As the climate continues to warm, plant and animal species that can only survive at lower latitudes will begin to take over the former taiga, perhaps slowly turning it into a boreal forest. Eventually, theoretically, the taiga could disappear. It also is found mostly in Canada.