As Wildfires Grow More Intense, Iconic Western Forests May Not Come Back

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Nearly two decades after the 2002 Hayman fire in Colorado, this high-severity burn area near Cheesman Lake is still treeless.

Michael Elizabeth Sakas/CPR News


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Michael Elizabeth Sakas/CPR News

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Forest ecologist Marin Chambers, of Colorado State University, stands in a burn area of the 2002 Hayman fire northwest of Colorado Springs.

Michael Elizabeth Sakas/CPR News


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Michael Elizabeth Sakas/CPR News

Forest ecologist Marin Chambers, of Colorado State University, stands in a burn area of the 2002 Hayman fire northwest of Colorado Springs.

Michael Elizabeth Sakas/CPR News

Forests become grasslands, and that’s bad for carbon emissions

For areas that can’t regenerate, research has found they may instead convert to grasslands.

Camille Stevens-Rumann, also of Colorado State University, says there can be lots of benefits to having patches of grasslands between forested areas. But it’s a problem «where we’re talking about tens of thousands of acres that have transitioned from forest to grasslands.»

One major concern is that trees sequester carbon. Fewer trees will capture less carbon, which means more warming, and therefore fewer trees, in a cycle that will make it hard to reach carbon neutrality.

Thomas Veblen, of the University of Colorado Boulder, says this poses a problem for tree replanting efforts touted as a way to combat climate change.

«Trees need moisture to survive, and they simply are not going to be surviving in the many, many places where we would like to have them planted and sequestering carbon,» he says.

Stevens-Rumann has studied a large range of burned forests across the West and found some areas no longer able to support the same trees that have been there for one or two centuries.

«We’re really moving away from the suitable climate for tree regeneration to happen,» she says.

But she wants to emphasize that Colorado is not losing all of its forests.

Some trees, like aspen and oak, do better with regrowth after a fire. She says lodgepole pine forests, such as what’s been burning in the Cameron Peak Fire north of Rocky Mountain National Park, have also been found to recover better than some lower-elevation trees. Fire actually makes their cones open to drop seeds.

In other cases, a different species may move in, or trees may migrate to higher, cooler elevations.

«That gives me hope for these landscapes,» she says. «And I think part of what we all have to accept, in this new and changing world, is that these ecosystems are going to look different than the ones that maybe we have grown fond of in the past.»

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