CU-Boulder researchers also have charted a doubling in atmospheric nitrogen deposition on Niwot Ridge in the past several decades -- primarily from automobile, agriculture, ranching and industrial activity -- that is now adversely affecting some aquatic and terrestrial life on the ridge, said Williams.
In addition, researchers are keeping a close eye on existing populations of the American pika, a potato-sized animal related to rabbits and found in rocky talus slopes as high as 13,000 feet on Niwot Ridge. Of 25 populations of pikas in the Great Basin of Nevada documented between 1898 to 1990, nine had disappeared by 2008, apparently the result of warming temperatures. Pikas in Colorado require deep snowpack during winter that serves to insulate them from extremely cold air temperatures, Williams said.
"Many consider the American pika a 'sentinel species' in terms of measuring the effects of climate change," said Williams. "Niwot Ridge has a cold, short growing season, and the biological activity that occurs there is on the razor's edge of environmental tolerance."
Despite a long-term warming and drying trend in mountainous areas of the West, 2011 was a striking anomaly, said Williams. "What we have seen around here is one of the largest and latest snowfall years on record in the high country and extreme dryness accompanied by an inordinate amount of winter wildfires around Boulder, which is only 15 miles as the crow flies from the Niwot Ridge study area. What has happened from Boulder west to the Continental Divide has been a total disconnect in terms of weather."
"The primary climate driver of the Niwot Ridge site is snow, and the mountains are our water tow
|Contact: Mark Williams|
University of Colorado at Boulder