Imagine a Yellowstone National Park without thick, verdant forests.
Some of the region’s top fire and forest scientists say the fires of 1988 are nothing compared to the size and frequency of those that will burn by the middle of this century. And lead researcher Anthony Westerling of the University of California Merced and his team of Monica Turner, Erica Smithwick, William Romme and Michael Ryan say Yellowstone is typical of what other areas in the West will experience as temperatures rise.
Their study confirms what earlier forest scientists have reported. The size and frequency of fires in the West already have risen since the 1988 fires, the signal fires of a changing climate. The process will continue no matter what we do and Westerling’s team modeled the logical direction of the flora under more frequent large fires.
“The magnitude of predicted increases in fire occurrence and area burned suggests that there is a real likelihood of Yellowstone’s forests being converted to non-forest vegetation during the mid-21st century because reduced fire intervals would likely preclude post-fire tree regeneration,” the scientists wrote in the peer-reviewed paper. “Continued warming could transform greater Yellowstone fire regimes by mid-21st century.”
Romme, of Colorado State University, was a young graduate student in 1988, mapping out past fires, when he discovered mid-summer that past fires were far larger than botanists and foresters had thought. He found evidence of a giant fire 300 years before that was much like the 750,000-acre fire that was to burn that year.
He stood alone at that time predicting a giant conflagration. He turned out to be the only one who was right.
But today Romme and the others are predicting the frequency of big fires in the high-elevation lodgepole pine-subalpine fir forest will drop to 30 years. At that frequency the high-elevation tree species that are there now won’t reproduce.
Think about all of birds, mammals and other creatures that live in those forests.
“Ecosystem resilience may be compromised by novel disturbance regimes and fire regimes may be sensitive indicators of tipping elements that exhibit threshold-like behavior and qualitatively change regional ecosystems,” the scientists wrote.
In other words, the greater Yellowstone ecosystem as we know it will be gone.
That should be a sobering thought for those who love Yellowstone, but it also has ramifications for the entire region. This is no longer just about the whitebark pine and the grizzly bear.
The Snake River begins in Yellowstone. So does the Yellowstone River.
The forests of Yellowstone, the Tetons and surrounding mountains store the water for more than a quarter of the continent’s supply. Losing those forests means losing much of the storage capacity that will already be taxed by warmer winters and earlier runoffs.
And note that these scientists and the others who have done similar studies expect the same kinds of effects throughout the Northern Rockies. Many of Idaho’s forests are very similar to Yellowstone’s.
And it is obvious we have seen the same increase in size and frequency in fires here as Yellowstone. The tougher question is what we can do about it.
The hardest answer is “nothing.”
Rocky Barker: 377-6484
