Tree growth in Colorado high country being monitored for signs of climate change
The Denver Post
NIWOT RIDGE, Colo. (AP) – Government-backed researchers are trying to spin the clock forward by erecting heat lamps and planting thousands of seedlings in Colorado’s high country to test whether climate change may cause the timberline to gradually march up the mountain.
No trees currently survive here, at 11,600 feet, where wind gusts can reach 90 miles per hour.
But early research results indicate that trees in a warmer Colorado would germinate seven weeks earlier than at present springtime tundra temperatures.
Monitoring tree growth as the heaters simulate climate change “tells us how sensitive species and ecosystems are to this type of warming,” said University of California Merced ecologist Lara Kueppers, principal investigator on the $3 million project.
“Instead of waiting for the big global experiment to play itself out, we are using these heaters to accelerate time, in a sense, and tell us something about what might happen if we stay the course with our current greenhouse-gas emissions,” Kueppers said. “A lot of changes have been unfolding over the past decade that we wouldn’t have expected so fast.”
For Colorado, trees growing higher up mountainsides could threaten species such as marmots, pika and ptarmigan that depend on open, cold habitat.
New tundra forests also could help mountains retain snow, altering runoff that supplies cities with water.
A team from western universities is conducting the research on U.S. Forest Service land beneath the Continental Divide, using the University of Colorado’s Mountain Research Station as a base. Researchers planted more than 10,000 limber pine and Engelmann spruce seedlings on three plots over the past two years.
The researchers set up steel frames that suspend 240 heat lamps over the seedlings. A year ago, they turned on the heaters, set to warm temperatures by 7 degrees – an amount the international consortium of climate scientists considers likely by the end of the century.
Now, the researchers hike up and fan out across the tundra every week with clipboards, measuring and recording the growth of seedlings and surrounding wildflowers.
“The data are still out on how many of these seedlings will make it. The alpine environment is still a harsh one, even with 7 or more degrees of warming,” Kueppers said.
The density of wildflowers under heaters increased by 10 percent to 15 percent, said forest entomologist Scott Ferrenberg, a project leader.
“Climate change is scary. We wonder about tipping points,” he said.
All data still must be analyzed and results submitted for peer review. Project leaders plan to continue measuring tree and wildflower growth for five years.
The U.S. Department of Energy funded the project as part of an effort to test what climate change may mean for the nation. In the past, climate scientists relied heavily on computer models.
But logistics prove difficult. Scientists double as engineers and electricians, running electrical wiring into the wilderness and maintaining it through snowstorms and other high-country hazards. Those include lightning strikes that knocked out a data-loading station, marmots that chew cables, and constant winds that loosen bolts and drive snow into containers.
As researchers crouched while recording measurements last week, a sudden wind disrupted them. It blew off five sheets containing several hours of observations by Sunny Sawyer, a 25-year-old University of California- Berkeley researcher.
Others spotted her papers skittering across the tundra. All dropped their own clipboards and bolted after the papers. Miles Daly sprinted 150 yards and then dove, hurling himself onto one sheet. Eventually all five were recovered, saving precious data.
“The theory is that the trees are moving up,” Sawyer said, gazing down at the highest forest from her plot beneath the rocky face of Navajo Peak.
“But there’s no real way to know until all the data is analyzed.”
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