VIDEO: Fire on the Mountain, Part Two
Twenty of us stood, casually grouped, among the Ponderosa pines on Reservoir Hill on October 4, as Pagosa Ranger District forester Steve Hartvigsen asked us to consider both the forest, and the trees.
“What are you noticing?” Steve asked, motioning toward the trunks and crown surrounding us.
The trees, spread out across the hillside before us. were all of the same species, but of course if you looked close, each tree had its own unique qualities. And the group of humans considering them were likewise of the same species, but we came to the task of observing the trees with various backgrounds and experiences — so naturally, we noticed different details about the forest.
One person pointed out that we were surrounded by a monoculture: all of the tall trees were Ponderosa pines. There were no spruce or fir or cedars or aspen or cottonwoods. Just pine trees, as far as we could see into the forest. And here and there, some small scrub oak. (Later in the hike, we would come across a few other species.) Another person asked why there were no baby pine trees. Another noted that the ground was mainly barren and needle-covered; there was little in the way of ground cover growing in this forest. Most of the trees were of about the same height, but here and there, a much older pine with reddish orange bark towered above the younger trees.
After a short walk, Steve pointed out some ancient stumps that he had marked with red ribbons. The stumps (we would understand later) were left from when Reservoir Hill was logged in the early 1900s. We each headed off to find a stump, and when we stopped, we saw that we, and the old stumps, were widely separated — maybe 50 to 100 feet from any nearby stump.
“That’s what the density of this forest used to be. Now look to see how many additional trees are on site in this same kind of circle. How many more trees? Is it six times as many? Is it maybe ten times as many?”
Ten younger trees for each old stump, suggested one person. Fifteen, said another. Trees crowded together, competing for the meager rainfall of our high mountain desert climate.
Steve talked about how Ponderosa pine is well adapted to surviving wildfire. And a good thing, perhaps. He showed us a couple of graphs showing the frequency of natural fires in the San Juan National Forest, based on studies of scarred trees that survived those fires. Up until about 1880, southwest Colorado forests saw wildfire about every 12 to 15 years. Presumably, the undergrowth was severely burned in those fires, but the pines generally survived.
Then around 1880, the fires stopped happening. What happened around 1880 in southwest Colorado?
Logging? someone suggested. No, that didn’t become common until about 1900, with the arrival of the railroads.
Fire suppression? another person suggested? The establishment of the Forest Service?
Steve smiled. “The Forest Service has done a lot of bad things, but we didn’t do that. We weren’t even around.” He suggested that fire suppression didn’t become effective or feasible until the establishment of a roads network in the 1940s. (As we’ve seen lately in the West, fire suppression is often ineffective, still in 2014.)
“Sheep,” said another person.
Steve agreed. “Sheep. That’s it. Sheep and cattle, but especially sheep. What happened, with those folks of Euro-American background — they came [into Colorado] — there weren’t that many of them, but they had hundreds of thousands of sheep.” The sheep cropped the forest undergrowth to barren ground. Fires could not longer spread easily, and essentially stopped occurring in these forests.
And beginning in the early 1900s, millions of young Ponderosa pine trees throughout southern Colorado grew up to be “teenagers” — creating forests like the one atop Reservoir Hill, where lack of sunlight and too many dropped needles and too much competion for scarce rainfall serve to keep the ground barren.
And where the only type of fire possible is catastrophic wildfire that kills the Ponderosa.
Read Part Three…