Eventually though, doug fir reverts back to a sort of weed status later on, when the accumulated effects of human fire suppression causes doug fir to start crowding out other species and interferes with the typical succession pattern. Harder to notice in the PNW, but if you look at NorCal especially, there are areas that would typically be a more open woodland with (say) oak. Instead these are jam-packed with doug fir due to lack of fire. From the perspective of anyone (whether human, animal, or plant) who misses the pre-suppression woodland state that's normally regulated by regular "good" fire, doug fir is indeed a weed. There normally isn't _this_ much of it stretching all the way from Alaska to Mexico.