A renowned landscape ecologist warns that longer wildland fire seasons and an increased number of incidents will likely significantly change the landscape of the Greater Yellowstone Ecosystem before the turn of the century.

Monica Turner, the Eugene P. Odum Professor of Ecology and a Vilas Research Professor in the Department of Integrative Biology at the University of Wisconsin-Madison, says that the future of Greater Yellowstone is uncertain due to warming temperatures and drier summers. These factors may drastically shorten intervals between landscape-changing fires and affect post-fire recovery.

In her research, she has found warming trends that suggest we will see increased intervals of fire, resulting in extensive areas of forested land receding in Yellowstone and surrounding areas, largely due to the decreased time before fires return to the same areas.

“Atmospheric CO2 levels are higher than anytime they have been in the past 3.3 million years and temperatures are hotter than they have been at any time in the past 20,000 years,” she said, adding, “in Yellowstone, the growing season is already two weeks longer than it used to be. That means fire season is two weeks longer as well.”

This comes as most days last week broke unofficial temperature records for the planet that experts have been tracking for decades. Turner said large fires that were once considered 100- to 300-year events could happen as often as 30-year intervals. It takes 200 years to fully grow a mature lodgepole pine forest, she said.

When the forest has time to mature, the trees that make-up area forests, including lodgepole and whitebark pines, develop more hardy cones that can withstand fires and are stimulated to drop seeds when fire strikes — as well as standing mature but dead trees providing at least some shade on the forest floor. Yet, if fires return before the trees have time to mature, other species will replace them and some vast forested areas will retreat to sparsely covered grassy meadows.

“We'll see more young forestry burning, and in some cases, we'll see a conversion of forests to meadows or grasslands,” she said while speaking to a crowd at the Coe Auditorium in the Buffalo Bill Center of the West last week.

Her research shows that even if there is dramatic changes in carbon dioxide levels in the atmosphere heading into 2050, there will be “extensive areas throughout the GYE where trees no longer can  grow back going into the next century.”

She said if our CO2 emissions are under control by mid century, we will still get warmer. “But if we stay on the course that we're on, we’ll get really much warmer.”

The warmer the environment gets, the higher the likelihood of a failure of the forest to rebound after fire.

“We go from historical conditions … where the time between fires would have been more than 120 years, like it's been for 10,000 years, and then as we go through the latter part of the century, the weather conditions that could give you big fires start to occur so frequently that they're happening every year. And that means that the weather conditions that could give you big fires — like 1988 — maybe happen every 20 years or every 30 years.”

Her research emphasizes causes and consequences of spatial heterogeneity in ecological systems, focusing primarily on ecosystem and landscape ecology. She has studied fire, vegetation dynamics, nutrient cycling, bark beetle outbreaks and climate change in Greater Yellowstone for over 25 years, including long-term research on the 1988 Yellowstone fires.

Turner said the scenarios of her research in collaboration with other ecologists “are not forecasts.”

“These are not predictions. I'm not going to say in 2079 this is what will happen. It's more like, in a sense, if you think about hurricane maps, when they give you lots of different trajectories, we're looking at lots of different outcomes, given the same weather conditions,” she said.

The Draper Museum’s Lunchtime Expedition lecture series, which takes place the first Thursday of each month, has been made possible through support from Sage Creek Ranch and the Nancy-Carroll Draper Charitable Foundation.