Glacier: The next 100 years

Melting glaciers. Warming rivers. Swarms of pine-devouring beetles. Forest fires.

These are a few of the challenges Glacier National Park will face in its second century.

"We will definitely have an overall drying as [global] temperatures increase," said Dan Fagre, a Glacier National Park research ecologist. "It will potentially lead to ecosystem changes that include insect outbreaks, forest fires, reduced stream flows and increased river temperatures. These are large-scale issues that will potentially transform the forest that we have."

Fagre noted that he and other scientists have recorded increases in extreme heat days throughout the year and decreases in extreme cold days.

"If these trends continue, the transformation of Glacier National Park is inevitable," Fagre said. "It means we will have a different Glacier National Park. It doesn't mean it will become an ugly place. It just won't be the park we intended to preserve when we created it."

As of 2010, there are about 25 glaciers larger than 25 acres -- the size scientists have pegged to constitute a glacier as opposed to a large field of ice and snow -- down from an estimated 150 in the late 19th century. The largest glaciers in the park are Harrison, Blackfoot and Jackson.

In 1968, the U.S. Geological Survey issued its first aerial photography of the glaciers, at which time there were 37 deemed large enough to be named, and 75 smaller glaciers.

The dwindling glaciers are not a new development in Glacier. Keith Fellbaum, a former Glacier Park chief of maintenance, recalled that in 1963 the Geological Survey was predicting that the park's glaciers eventually would disappear.

"It was understood and accepted by the National Park Service and the U.S. Geological Survey that the park glaciers were a remnant of the last ice age and would eventually melt," Fellbaum wrote.

He also noted that the park was named Glacier because of the topography created by glaciers, not because of the glaciers themselves.

Fagre said the ecosystem in the park is dependent on the glaciers.

"Glaciers represent the environmental state of an area," he said. "They are there because of a balance of temperatures and precipitation. If you see long-term changes in glaciers, you're seeing long-term changes in climate. They are barometers of climate."

The park ecologist said that glaciers hold decades worth of snow. In the summer, they melt a little, releasing freezing water into alpine streams, which keeps the temperatures of the waterways from rising beyond what native fish have adapted to. As glaciers diminish, the streams warm and the native fish populations suffer.

ANOTHER THREAT to Glacier National Park comes from the mountain pine beetle and the spruce budworm. Another heavily forested state, Colorado, has already seen the affects of beetle-kill. More than 19 million square acres have been decimated by the beetles.

To kill pine-beetle populations, winter temperatures must drop to minus 22 to 40 degrees Fahrenheit for at least several days, or at least 12 hours of 40 below or lower. Additionally, warmer summers allow the beetles to reproduce twice.

"We wind up with huge outbreaks," Fagre said. "Many entomologists think this will occur much more frequently."

With many acres of rust-colored dead trees comes a susceptibility to forest fires.

"Forest fires have become larger and more common," Fagre said. "When the snowpack melts earlier in the season, more fuels are being grown late in the season. The forests are drier than before."

Park officials cannot affect rising summer temperatures, but they may make decisions to mitigate fire danger in the future, Fagre said.

Jack Potter, Glacier's chief of science and resources management, said the park has developed a generalized strategy to address the issues. Potter outlined a four-step plan: mitigation, adaptive management, education and research using science.

To mitigate the changes, he said, the park must make sure it is doing the right things. It must adapt to manage species vulnerability and reduce the stressors of exotic animals and plants. It must educate visitors to Glacier about how climate change affects their lives as well as the lives of park wildlife.

Scientists also will study how stressors affect creatures in Glacier Park, such as how fish adapt to warmer waters.

Additionally, Potter noted that park officials are working to create better forest-fire policies.

"We are reducing brush and have tightened up planning with [Glacier Park] neighbors," he said. "We have targeted a few places for potential burns and have done active fuel reduction around buildings at St. Mary, Two Medicine and Many Glacier."

If temperatures continue to rise, these changes to forest and wildlife management could be the way of the future. One way to help the native fish adapt to warming rivers is to aggressively remove non-native, invasive species of fish.

"We can address stresses within a management purview," Fagre said. "As much as we think we know about natural systems, they surprise us. Some are more delicate. But there are pockets of resilience like the American pika.

"It's important to look at the future of the park," he said. "We can change and accommodate. We're not helpless. We need to identify the things we can do and get after it."