As at least half a dozen fires in Colorado force hundreds to evacuate, and have closed a national forest, some residents say they’re shocked at how quickly the fire has spread. The speed of wildfires is actually something Colorado ecologists have been studying, and they say history may provide clues on how to slow it down.
A key focus is the blanket of post-card perfect evergreen forests the state is known for, but whose lower elevations have become far more crowded than they were a century ago.
“The first thing I see is we’re missing the meadows. Where are the meadows?” asks Tony Cheng, director of the Colorado Forest Restoration Institute at Colorado State University.
Cheng, along with Peter Brown of the Rocky Mountain Tree-Ring Research organization, researched the history of forests at Hall Ranch, a 4,000 acre recreation area in Boulder County. On one plot he shows me, a carpet of pointy green trees crowds out the light. Brown says there are “ten times as many trees in these stands as there were historically.”
Euro-American settlement in the 1860’s dramatically changed Colorado’s forests. Before then, large open meadows separated small stands of ponderosa pines. Low intensity wildfires would have moved through those stands regularly.
Today, generations of livestock grazing and mining have reshaped forests, as has the creation of an agency devoted to curbing wildfires.
In Colorado, some forests haven’t seen fire in more than a century. They are more dense, and thick with undergrowth. That means when fires do happen, there’s more fuel for them to burn hotter, and they can spread faster from treetop to treetop.
Now, Cheng and Brown’s research, published in April in Forest Ecology and Management, offers specific guidelines to help restore and manage Colorado’s forests in a way they say is more friendly to wildfire. Similar research has been done in Oregon and New Mexico.