"The 'three stooges' that brought about the forest conditions that we have today are logging, fire suppression, and cattle grazing."
The "three stooges" that brought about the forest conditions that we have today is logging, fire suppression, and cattle grazing. Logging, obviously, has removed a lot of the large trees that made up the old-growth structure that we used to have around Flagstaff and throughout the West. In many places, there's just not.... In some places it's not there at all, or if it is there, it's at a much lower density, much smaller component of the forest than it used to be. It's big yellow pines in those open areas, and also [groupy?] structure, and groups of big, fat trees that were taken with the railroad logging and the timber sales since.
The fire suppression allowed all of the seedlings that got a start to pretty much make a go of it and develop all the way up into the small-diameter blackjacks that we see throughout the forest now. Because before fire suppression, fires would come through and kill those smaller trees, and the larger yellow-bellies were more resistant to those ground fires and wouldn't be burned up or killed like the seedlings and saplings would. So fire suppression allowed them all to grow, and now we have a very dense forest full of very small trees.
But along with that we had cattle grazing for the past hundred years. What one of the impacts of cattle grazing is, is that it removes all of the grass, and ponderosa pine seedlings are actually so shade intolerant that they need full sunlight so much, that the grasses, the tall grasses that used to exist, would shade them out and they would not grow. So in open areas, you would have the trees encroaching or filling it up, because the grasses would out-compete for sunlight, the seeds and seedlings, and especially the small seedlings of ponderosa pine. Well, remove all those grasses, and they have a chance to go for it. On top of it, you have fire suppression, so they really have a chance to go for it. So the impacts of the cattle are evident throughout the forest as we walk through any of the national forests in the West.