Colorado’s Front Range fire severity today not much different than in past, says CU-Boulder study
The perception that Colorado’s Front Range wildfires are becoming increasingly severe does not hold much water scientifically, according to a massive new study led by the University of Colorado Boulder and Humboldt State University in Arcata, Calif.
The study authors, who looked at 1.3 million acres of ponderosa pine and mixed conifer forest from Teller County west of Colorado Springs through Larimer County west and north of Fort Collins, reconstructed the timing and severity of past fires using fire-scarred trees and tree-ring data going back to the 1600s. Only 16 percent of the study area showed a shift from historically low-severity fires to severe, potential crown fires that can jump from treetop to treetop.
The idea that modern fires are larger and more severe as a result of fire suppression that allowed forest fuels to build up in the past century is still prevalent among some, said CU-Boulder geography Professor Thomas Veblen, a study co-author. “The key point here is that modern fires in these Front Range forests are not radically different from the fire severity of the region prior to any effects of fire suppression,” he said.
A paper on the subject was published Sept. 24 in the journal PLOS ONE. The study was led by Associate Professor Rosemary Sherriff of Humboldt State University and involved Research Scientist Tania Schoennagel of CU-Boulder’s Institute of Arctic and Alpine Research, CU-Boulder doctoral student Meredith Gartner and Associate Professor Rutherford Platt of Gettysburg College in Gettysburg, Pa.
The study was funded by the National Science Foundation.
“The common assumption is that fires are now more severe and are killing higher percentages of trees,” said Sherriff, who completed her doctorate at CU-Boulder under Veblen in 2004. “Our results show that this is not the case on the Front Range except for the lowest elevation forests and woodlands.”
One important new finding comes from a comparison of nine large fires that have occurred on the Front Range since 2000 — including the 2002 Hayman Fire southwest of Denver, the 2010 Fourmile Canyon Fire west of Boulder and the 2012 High Park Fire west of Fort Collins — with historic fire effects in the region.
“It’s true that the Colorado Front Range has experienced a number of large fires recently,” said Schoennagel. “While more area has burned recently compared to prior decades – with more homes coming into the line of fire – the severity of recent fires is not unprecedented when we look at fire records going back before the 1900s.”