Posts tagged Mountain Research Station
CU study: Nitrogen damage to RMNP could become irreversible
Jul 10th
A new study led by the University of Colorado Boulder indicates air pollution in the form of nitrogen compounds emanating from power plants, automobiles and agriculture is changing the alpine vegetation in Rocky Mountain National Park.
The emissions of nitrogen compounds to the atmosphere are being carried to remote areas of the park, altering sensitive ecosystems, said CU-Boulder Professor William Bowman, who directs CU-Boulder’s Mountain Research Station west of Boulder and who led the study. “The changes are subtle, but important,” he said. “They represent a first step in a series of changes which may be relatively irreversible.”
A new study led by the University of Colorado Boulder indicates air pollution in the form of nitrogen compounds emanating from power plants, automobiles and agriculture is changing the alpine vegetation in Rocky Mountain National Park.
The emissions of nitrogen compounds to the atmosphere are being carried to remote areas of the park, altering sensitive ecosystems, said CU-Boulder Professor William Bowman, who directs CU-Boulder’s Mountain Research Station west of Boulder and who led the study. “The changes are subtle, but important,” he said. “They represent a first step in a series of changes which may be relatively irreversible.”
In other regions of the world, higher amounts of nitrogen pollutants correlate with decreased biodiversity, acidified soils and dead stream organisms like trout, said Bowman. “There is evidence that indicates once these changes occur, they can be difficult if not impossible to reverse. It is best to recognize these early stages before the more harmful later stages happen.”
The study site was an alpine meadow roughly one mile east of Chapin Pass in the Mummy Range of Rocky Mountain National Park. Bowman and his team analyzed the plant communities and soils under ambient levels of nitrogen deposition and compared them to plots with added nitrogen to simulate the increasing atmospheric nitrogen pollution expected in the coming decades. The results indicated changes in plant abundances already were occurring under ambient conditions, but to date no changes in soils were detected.
During the course of the three-year study, rising levels of nitrogen in the soils correlated with large increases in a common species of sedge shown to flourish in other nitrogen addition studies. Bowman said the team anticipates that the diversity of vascular plant species will rise with increasing nitrogen deposition, then decrease with more rare species being excluded by competition from other plant species. “While the changes are relatively modest, they portend that other more environmentally adverse impacts may be on the horizon in Colorado’s alpine areas,” said Bowman.
A paper on the subject was published in the June issue of the Journal of Environmental Management. Co-authors on the study included John Murgel, a former CU-Boulder undergraduate student now completing graduate work at Colorado State University, and Tamara Blett and Ellen Porter of the Air Resources Division of the National Park Service in Lakewood, Colo. The study was funded by the National Park Service.
Previous studies by Bowman and others have shown vegetation changes and soil acidification has been occurring due to increasing nitrogen deposition at other alpine sites in Colorado, including Niwot Ridge. Niwot Ridge is a National Science Foundation-funded Long-Term Ecological Research site administered by CU-Boulder and located adjacent to the university’s Mountain Research Station located some 30 miles west of the city.
Given the projected population growth in Front Range cities in the greater Denver area and increasing agricultural development, nitrogen deposition is expected to increase steadily in Rocky Mountain National Park over the next several decades, said Bowman, a professor in CU-Boulder’s ecology and evolutionary biology department.
The high-elevation ecosystems of the park are a magnet for thousands of visitors each year who have opportunities to see plants and animals well adapted to the severe climate above treeline, said Bowman, but such ecosystems are the most sensitive to adverse impacts from air pollutants. Previous studies by other researchers have documented ongoing changes in the algae found in several of the Rocky Mountain National Park’s high elevation lakes due to nitrogen pollution, he said.
While the park is also a haven for fishermen hoping to catch trout in pristine waters, continued inputs of nitrogen pollutants are a hazard to the health of both trout and their food sources, said Bowman, also a fellow of CU-Boulder’s Institute of Arctic and Alpine Research. It starts when the ability of the land plants and soils to take up the nitrogen is exceeded, causing soils to become acidified, he said.
Other parts of the Colorado Front Range have exhibited signs of acidification at the highest elevations, Bowman said. “Once this happens, soluble aluminum leaches from soils and begins to show up in streams and lakes. This aluminum is quite toxic to many aquatic animals,” he said.
“The take-home message is that the amount of nitrogen deposition reaching the tundra in Rocky Mountain National Park has already passed an important threshold and may lead to more serious environmental impacts,” said Bowman. “It’s not inconceivable that continued negative ecological impacts in the park due to nitrogen pollution could eventually impact tourism in Colorado.”
Officials from Environmental Defense and Trout Unlimited petitioned the State of Colorado and the Environmental Protection Agency to reduce emissions of nitrogen pollution in 2004. This effort resulted in a 2007 plan to lower nitrogen emissions on a voluntary basis to reduce impacts to Rocky Mountain National Park.
Excel Energy’s recent switch to natural gas in some of its power plants is one of many steps toward limiting nitrogen emissions, said Bowman. Ongoing efforts by air quality managers and representatives from the Colorado agricultural industry are also working on management practices that would lower nitrogen emissions.
In other regions of the world, higher amounts of nitrogen pollutants correlate with decreased biodiversity, acidified soils and dead stream organisms like trout, said Bowman. “There is evidence that indicates once these changes occur, they can be difficult if not impossible to reverse. It is best to recognize these early stages before the more harmful later stages happen.”
The study site was an alpine meadow roughly one mile east of Chapin Pass in the Mummy Range of Rocky Mountain National Park. Bowman and his team analyzed the plant communities and soils under ambient levels of nitrogen deposition and compared them to plots with added nitrogen to simulate the increasing atmospheric nitrogen pollution expected in the coming decades. The results indicated changes in plant abundances already were occurring under ambient conditions, but to date no changes in soils were detected.
During the course of the three-year study, rising levels of nitrogen in the soils correlated with large increases in a common species of sedge shown to flourish in other nitrogen addition studies. Bowman said the team anticipates that the diversity of vascular plant species will rise with increasing nitrogen deposition, then decrease with more rare species being excluded by competition from other plant species. “While the changes are relatively modest, they portend that other more environmentally adverse impacts may be on the horizon in Colorado’s alpine areas,” said Bowman.
A paper on the subject was published in the June issue of the Journal of Environmental Management. Co-authors on the study included John Murgel, a former CU-Boulder undergraduate student now completing graduate work at Colorado State University, and Tamara Blett and Ellen Porter of the Air Resources Division of the National Park Service in Lakewood, Colo. The study was funded by the National Park Service.
Previous studies by Bowman and others have shown vegetation changes and soil acidification has been occurring due to increasing nitrogen deposition at other alpine sites in Colorado, including Niwot Ridge. Niwot Ridge is a National Science Foundation-funded Long-Term Ecological Research site administered by CU-Boulder and located adjacent to the university’s Mountain Research Station located some 30 miles west of the city.
Given the projected population growth in Front Range cities in the greater Denver area and increasing agricultural development, nitrogen deposition is expected to increase steadily in Rocky Mountain National Park over the next several decades, said Bowman, a professor in CU-Boulder’s ecology and evolutionary biology department.
The high-elevation ecosystems of the park are a magnet for thousands of visitors each year who have opportunities to see plants and animals well adapted to the severe climate above treeline, said Bowman, but such ecosystems are the most sensitive to adverse impacts from air pollutants. Previous studies by other researchers have documented ongoing changes in the algae found in several of the Rocky Mountain National Park’s high elevation lakes due to nitrogen pollution, he said.
While the park is also a haven for fishermen hoping to catch trout in pristine waters, continued inputs of nitrogen pollutants are a hazard to the health of both trout and their food sources, said Bowman, also a fellow of CU-Boulder’s Institute of Arctic and Alpine Research. It starts when the ability of the land plants and soils to take up the nitrogen is exceeded, causing soils to become acidified, he said.
Other parts of the Colorado Front Range have exhibited signs of acidification at the highest elevations, Bowman said. “Once this happens, soluble aluminum leaches from soils and begins to show up in streams and lakes. This aluminum is quite toxic to many aquatic animals,” he said.
“The take-home message is that the amount of nitrogen deposition reaching the tundra in Rocky Mountain National Park has already passed an important threshold and may lead to more serious environmental impacts,” said Bowman. “It’s not inconceivable that continued negative ecological impacts in the park due to nitrogen pollution could eventually impact tourism in Colorado.”
Officials from Environmental Defense and Trout Unlimited petitioned the State of Colorado and the Environmental Protection Agency to reduce emissions of nitrogen pollution in 2004. This effort resulted in a 2007 plan to lower nitrogen emissions on a voluntary basis to reduce impacts to Rocky Mountain National Park.
Excel Energy’s recent switch to natural gas in some of its power plants is one of many steps toward limiting nitrogen emissions, said Bowman. Ongoing efforts by air quality managers and representatives from the Colorado agricultural industry are also working on management practices that would lower nitrogen emissions.
NSF AWARDS CU-BOULDER $5.9 MILLION GRANT FOR ALPINE ECOSYSTEM RESEARCH
Jun 16th
The National Science Foundation has awarded the University of Colorado Boulder a six-year, $5.9 million grant to continue intensive studies of long-term ecological changes in Colorado’s high mountains, both natural and human-caused, over decades and centuries.
Awarded to CU-Boulder’s Institute of Arctic and Alpine Research, the renewal grant will allow faculty and students, including undergraduates, to continue key environmental studies at the Niwot Ridge Long-Term Ecological Research, or LTER, site west of Boulder. The study site, considered extremely sensitive to climate change, is adjacent to CU-Boulder’s Mountain Research Station and encompasses several thousand acres of tundra, talus slopes, glacial lakes and wetlands stretching to the top of the Continental Divide.
The grant is the largest environmental sciences award in CU-Boulder history, said INSTAAR Fellow Mark Williams, principal investigator on the grant. In 2005, NSF awarded CU-Boulder a $4.9 million renewal grant for environmental studies at the Niwot Ridge site. As one of five initial LTER sites selected by NSF in 1980, Niwot Ridge is now one of 25 such sites in North America and the only one located in an alpine environment, said Williams.
“CU-Boulder has a worldwide reputation for monitoring global climate change from Greenland to Antarctica and its impacts on natural ecosystems and human populations,” said Vice Chancellor for Research Stein Sture. “To direct such a key program in our own backyard for the National Science Foundation is crucial from an environmental science standpoint and unique in that it provides a spectacular training ground for our students to work side-by-side with some of the world’s best climate change scientists.”
Recent climate studies have predicted the mountainous areas of the American West will become both hotter and drier in the coming years, and long-term meteorological measurements on Niwot Ridge indicate the alpine climate there has warmed slightly in recent decades, said Williams, also a professor in the geography department. The temperatures are significant because even small changes in alpine ecosystems can cascade down and have negative effects on other ecosystems, he said.
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 towers,” said Williams. “As the alpine climate changes, one of the biggest impacts on humans will be a change in water resources. Even if we end up with the same amount of precipitation, in the form of less snow and more rain, we are going to end up with less usable water for municipalities.”
There already are some indications that the snowline in the Rocky Mountains is moving upward, which will affect the abundance and distribution of plants and animals and likely shorten the annual ski seasons at resorts throughout the West in the future, he said.
The Niwot Ridge site is a huge benefit to CU-Boulder students, said Williams. “I have five undergraduates working in my chemistry lab this summer. Not only do they get paid, but they learn valuable research skills.” The LTER grant funds research for about 15 CU-Boulder graduate students and 25 to 30 undergraduates annually, Williams said, and there are more than a dozen CU-Boulder faculty members that are co-investigators on the new Niwot Ridge LTER program grant.
CU-Boulder ecology and environmental biology department Professor William Bowman, director of CU-Boulder’s Mountain Research Station for the past 20 years, said the Niwot Ridge site has been gaining momentum in stature from its beginnings by the consistent, high-quality research that has resulted in many publications in top-tier science journals.
More than half of the research on Niwot Ridge is by scientists and students from around the world that are not associated with the LTER program, said Bowman, also an INSTAAR fellow and who leads a team studying how air pollution, including nitrogen deposition, threatens biological and aquatic communities in U.S. national parks. There are currently 12 undergraduates conducting research at the Niwot Ridge site as part of the NSF’s Research Experience for Undergraduates program, said Bowman, who also is mentoring a student researcher at Niwot Ridge from Fairview High School in Boulder.
