The frequency of large fires in the greater Yellowstone ecosystem could increase with climate change to a point that dramatic shifts in the forest vegetation could result, from conifer-dominated mature forests to younger stands and more open vegetation, researchers said.
"Large, severe fires are normal for this ecosystem. It has burned this way about every few hundred years for thousands of years," said study author Monica Turner, a professor of ecology at the University of Wisconsin-Madison.
"But if the current relationship between climate and large fires holds true, a warming climate will drive more frequent large fires in the greater Yellowstone ecosystem in the future."
Wildfires in this ecosystem are mostly climate-driven and are more likely in the hotter, drier conditions predicted by numerous global climate models, a UW-M release said.
"What surprised us about our results was the speed and scale of the projected changes in fire in greater Yellowstone," said lead author Anthony Westerling, a professor of environmental engineering and geography at the University of California, Merced.
"We expected fire to increase with increased temperatures, but we did not expect it to increase so much or so quickly. We were also surprised by how consistent the changes were across different climate projections."
Fires larger than 500 acres will likely be an annual occurrence by 2050, the study said, with fire rotation -- the time span over which the entire landscape burns -- reduced from a historic range of 100 to 300 years to less than 30 years.
"More frequent fires will not be catastrophic to the area -- Yellowstone will not be destroyed -- but they will undoubtedly lead to major shifts in the vegetation," Turner said. "It is critical to keep monitoring these forests and study how they respond to future fires."