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This May, Denver saw more than 4 inches a rain, doubling the city’s historic average and outpacing famously rainy places like Seattle.

While the additional moisture has painted the Front Range a lush green, to grassland ecologist Katharine Suding, it’s concerning.

“Wet springs mean more plant growth,” said Suding, distinguished professor in the Department of Ecology and Evolutionary Biology and “That growth would turn into fuel later in the season.”

Without interventions to reduce the amount of dry vegetation in the fall and winter, the region could face intense and fast-spreading wildfire if one breaks out.

Katharine Suding. (Credit: Casey A. Cass/University of Colorado)

To Suding, this spring felt all too familiar. In 2021, a wet spring set the stage for the Marshall Fire later in December. The fast-moving fire destroyed more than 1,000 homes in ������ý���� and its surrounding suburbs like Louisville and Superior.

While forest fires tend to receive more attention, grassland fires are becoming a bigger problem nationwide. has suggested that in the United States, grassland and shrubland fires are burning more land and destroying more homes than forest fires.

“We should think about grasslands far differently than forests,” said Suding, standing in front of a grassland in Superior that the Marshall Fire swept through. “Knowing how to manage forests for fires does not necessarily mean that we can take that knowledge and apply it to the grassland system at all.”

As out-of-control wildfires rage in places like the Canadian prairies, Suding spoke to CU ������ý���� Today about these fast-moving grassland fires and potential ways to manage them.

What makes grassland fires so dangerous?

People might think forests are riskier, because there’s more biomass to burn. And that’s absolutely the case. But in grasslands, fires can burn really fast under hot, windy conditions. They can also spread very quickly and even jump barriers we once thought would stop them, like paved roads.

For example, the Marshall Fire crossed the U.S. Interstate 36. Some of the intense, fast-moving fire characteristics that we thought were mostly a forest fire problem are now occurring in grassland fires as well.

For states like Colorado with elevated grassland fire risks, when does the fire season begin?

In grasslands, fires typically start when the green vegetation turns brown at the end of their growing season. That’s usually August, with peak fire danger in October and November. But as the climate warms, we’re now extending the fire season into winter. The Marshall Fire happened in December. Fires are even popping up in early spring, before new green growth has a chance to return.

Where else are grassland wildfires becoming a growing concern?

Many places are starting to realize they face grassland fire risks, with Colorado seeing some of the earliest impacts. But it’s happening in California, Texas, Oklahoma, and throughout the Southwest as well.

How is climate change shifting the fire patterns?��

Colorado and many other grasslands regions are getting hotter and drier. That means plants may stop growing, or senesce, earlier when it’s too dry, leaving behind dry, dead material that sits on the landscape for longer. That’s what happened the year of the Marshall fire, and it’s happening more and more often.

We are also seeing increasing wind speed in the fall and winter in areas like Colorado and California. The combination of high wind and dry vegetation is the riskiest situation for grasslands.

What can be done to reduce fire risks in grasslands?

It isn't quite clear what exactly we can do to make these grasslands less risky for the people that live right next to them, because we’re just starting to understand these fires.

At CU ������ý����, we’re working with a group of local partners,��including ������ý���� County, the city authorities of ������ý����, Superior and Louisville, to try out some techniques. For example, we have tested grazing, which uses cattle or goats to eat down tall grasses. We’re also testing out mowing, as well as prescribed burning to reduce fuel in a controlled way.

Unlike forests, where you might thin trees and not have to return for years, grass regrows quickly. So, all of these interventions have to happen multiple times in a summer.

Some preliminary research suggests a combination of grazing and prescribed burning may work better than either alone, but there’s still a lot to learn. With funding from the��,����e are just on the cusp of trying to figure out how we can manage fires without removing all the grasses and turn the area into just a dust bowl.

For those living near fire-prone grasslands, is there something they can do to make their home more resilient?�� ����

One thing to do is avoid having tall, dead plants, as well as plants that catch on fire quickly, around their homes. The City of ������ý���� is encouraging people to remove junipers, highly flammable shrubs, from their yards. Planting native wildflower plants instead would be helpful, because they tend to be less flammable. Also, reducing vegetation density around homes can reduce risk.��