Human beings can not only harvest the trees without harming the environment, but of course real forest people know that it must be done if the forest is to be healthy. But beyond that it is actually possible for people to live in the forest without harming the environment. The environmentalists have a fetish about getting people and people's activities out of the forest. In some locations the environmentalists have their way and as a result no mature trees are harvested. The forest goes downhill badly with all the negative results I mentioned above.
Another big fetish of the enviro-nazis is nuclear power. If america had nuclear power plant regulations to France, Germany, England or Japan, then we'd use much more nuclear power rather than coal/oil to generate electricity. Instead we've regulated that industry to death out of fear instigated by the enviro-nazis. The end result is perhaps 5,000 americans dying prematurely every year due to emphyszema whereas if we had the same amount of nuclear generation of electricity as those other countries, then these people wouldn't die prematurely.
We've created a situation where strictly due to regulations that other nations think are stupid we are the only advanced nation that can't get the bulk of its electricity from nuclear power. GE can build 2 dozen nuke plants in China safely, but cannot build a single one in the US. We haven't built any nuke plants in over 20 years.