Posts tagged change
BEETLE KILL LIKELY TO WORSEN HIGH RUNOFF
Jun 8th
ACCUMULATION AND MELT, SAYS CU-BOULDER STUDY
A new University of Colorado Boulder study indicates the infestation of trees by mountain pine beetles in the high country across the West could potentially trigger earlier snowmelt and increase water yields from snowpack that accumulates beneath affected trees.
Led by CU-Boulder geological sciences department doctoral student Evan Pugh, the study was undertaken near Grand Lake, Colo., adjacent to Rocky Mountain National Park, an area that has been devastated by mountain pine beetle attacks in recent years. Mountain pine beetles have killed more than 4 million acres of lodgepole pine trees in Colorado and southern Wyoming since 1996, the most severe outbreak on record.
Pugh and his team monitored eight pairs of tree stands, each pair consisting of one live stand and one dead stand roughly an acre each in size and located adjacent to each other, sharing the same topography, elevation and slope. The team monitored the two distinct phases of pine beetle tree death during the three-year study — the “red phase” in which dead trees still retained red needles, and the “gray phase” in which all of the tree needles and some small branches had been shed, said Pugh.
The study showed that there was roughly 15 percent more snow accumulation under the gray phase stands than under living stands or red phase stands, likely due in large part to a lack of “snow interception” by needled tree branches that can cause snowflakes to “sublimate” into gas and return to the atmosphere, he said. Gray phase trees also allow more solar radiation through their canopies than live trees and red phase trees, increasing the potential for earlier melt, said Pugh, lead study author.
Snowmelt rates were highest under red phase trees, with snow disappearing up to a week earlier than snow in adjacent, healthy stands even though both received the same amount of snowfall at their bases. Pugh showed the earlier snowmelt in red phase tree stands is due in large part to the amount of litter — needles and branches — that drops or is blown from the trees onto on the snow surface, decreasing its solar reflecting power, or albedo, and causing it to absorb more of the sun’s radiation and heat up slightly.
“This is the first study to look at the potential effects that different stages of mountain pine beetle tree death may have on snowmelt,” Pugh said. “What we are seeing is earlier snowmelt and more snow accumulation in dead forests.”
A paper on the subject was published online today in the peer-reviewed journal, Ecohydrology. The paper was co-authored by CU-Boulder geological sciences Professor Eric Small and funded in part by a CU-Boulder Innovative Seed Grant. Four undergraduates — Leslie Baehr, Tevis Blom, Bryant Kealey and Jon Hammond — received internship credit for helping to conduct the research.
The study took place at the headwaters of the Colorado River in north-central Colorado. Six of the eight healthy tree stands in the study were made up primarily of lodgepole pines, while two were made up of mixed conifer trees. “One of the hardest parts of this study was to find stands of healthy trees in this area,” said Pugh.
The red phase that occurs following tree death usually lasts about 18 months, and the onset of the gray phase occurs about three or four years after tree death, said Pugh.
“One of the big surprises to me was that changes in snowpack depth and snowmelt timing as a result of the pine beetle outbreak were not larger,” said Small. But the continuing effects could become more significant in the coming decades, he said.
The CU-Boulder team used a wide variety of instruments during the study. In addition to avalanche poles used to periodically measure the snow depth at the 16 study stands, the team also inserted tiny thermometers at various snow depths to help them predict when the snow would likely melt. They also dug snow pits in each of the tree stands and weighed known volumes of snow to calculate density and water content.
Pugh’s team also used devices known as pyranometers to measure the snow surface albedo and the transmission of sunlight through forest canopies. Fisheye camera images taken from the snow surface helped the researchers to calculate the size and structure of the various tree stand canopies, he said.
“The students really got something out of working on this project,” said Small. “Not only did they get internship credit, they had a chance to conduct meaningful research.”
A massive fire in the study area in the late 1800s resulted in most of the succeeding lodgepole pines to be about the same size and age, making them easier targets for pine beetles. While mountain pine beetle infestations are natural events, climate change probably has played a role in the most recent outbreak. Drought conditions in the West in recent years have caused living pines to absorb less water, decreasing their ability to produce enough sap to “pitch out” beetles that are attacking them, Pugh said.
Water managers in Salt Lake City have reported extra water in river basins that hydrologic models had not predicted, Pugh said, an indication beetle-killed trees are having an impact on meltwater.
With the exception of two studies in British Columbia looking at the effects of beetle- killed lodgepole pine trees on snow accumulation and melt on flat terrain at a single site, research regarding the hydrologic impacts of mountain pine beetles has largely been speculative, said Pugh.
“Our study is the first to analyze the multiple stages of tree death from mountain pine beetles and their different impacts on snow accumulation and snowmelt,” said Pugh. “There is no on/off switch here — only gradual changes.
“The effects of the beetle-killed tree stands in terms of snow accumulation are not going to affect ski resort seasons by any means,” he said. “What we can say is there likely will be additional water resources for water managers. Additional snowpack coupled with dead trees that are no longer sucking up water will likely lead to more runoff.”
CU STUDENT INSTALLATIONS TO HELP ENGAGE COMMUNITY IN UNIVERSITY HILL DEVELOPMENT
Jun 1st
The temporary installations will serve as the basis of a community charrette, an intense planning and design collaboration, from 8:30 to 11:30 a.m. on June 3. The event is part of the International Town & Gown Association conference and is cosponsored by the city of Boulder.
“We take great pride in partnering with the city to provide opportunities for students to solve real-world problems,” said Frank Bruno, vice chancellor for administration. “The ability of our students to connect and engage the University Hill community through this interdisciplinary project is truly remarkable and can result in progress for the neighborhood.”
Charrette participants will explore revitalization ideas for University Hill that encompass the education, research and community service resources of CU-Boulder and the vibrant culture of the area as a commercial and residential district, according to organizers.
The project stems from a CU-Boulder Maymester course called Finding Ground. The student works include two interactive survey boards, two tables and 25 hammocks, all for public use.
“The installations are meant to bring people together to explore ideas for community connectedness and the overall use of public space,” said Finding Ground student Richard Mapes, a senior in architecture. “It’s amazing to see so many groups working to positively change the course of University Hill.”
Students carried out mapping exercises, interviews, precedent studies and presentations. They also conceptualized, designed and built the installations.
“We are excited about the close collaboration we’ve had with the university in preparing for this event, and look forward to learning more about the students’ work and their creative ideas during Friday’s charrette,” said David Driskell, executive director of Community Planning and Sustainability for the city of Boulder. “University Hill is a unique Boulder neighborhood, where the university and community literally come together. This course and Friday’s activities are just one example of how we can work together to make the Hill a vibrant and successful place that is welcoming for everybody.”
Students also maintained a group blog and developed a quick response code, which is displayed on three project information signs located on University Hill. It also will be stenciled in chalk on University Hill sidewalks. Visitors with the appropriate cellular phone technology can scan the QR code to be linked to the project website for more information.
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CU, MIT TOP UNIVERSITIES FOR DEPARTMENT OF ENERGY EARLY CAREER RESEARCH AWARDS
May 17th
The three CU-Boulder winners — Alireza Doostan of the aerospace engineering sciences department, Minhyea Lee of the physics department and Alexis Templeton of the geological sciences department — were among 65 winners nationwide selected by the DOE in 2011. They join four other CU-Boulder faculty selected in the 2010 — the most of any university in the nation — making CU-Boulder and MIT tops in the country with seven faculty each in the DOE Early Career Research Program.
Trailing CU-Boulder and MIT in total awards for the program in 2010 and 2011 were such schools as Princeton University, Caltech, the University of California, San Diego and the University of Wisconsin-Madison.
“For CU-Boulder to be honored by the U.S. Department of Energy with seven of these coveted Early Career Research Program awards in the past two years is testimony to our excellence as a research university and our ability to recruit extremely talented young faculty,” said CU-Boulder Vice Chancellor for Research Stein Sture. “It also is great news for our students, who will be even more involved in critical energy research efforts that benefit Colorado, the nation and world,” said Sture, also dean of the graduate school.
Templeton will be exploring chemical reactions between water, carbon dioxide and several common minerals found beneath Earth’s surface, including olivine, which become unstable in water and will dissolve. Chemical reactions caused by dissolving olivine can react with and sequester CO2, essentially taking it out of the atmosphere and water and storing it in other rocks.
The twist, said Templeton, is that all of the experiments will be conducted in the presence and absence of bacteria that can survive extreme conditions. She and her team will be using high energy X-rays to study how “extremophiles” that can survive such high temperatures and pressures in the deep subsurface might change the reaction pathway involved in dissolving the rocks, producing new minerals, or creating other greenhouse gases like methane.
Lee’s research is focused on uncovering and identifying new states of matter resulting from strong interactions between electrons. The effort involves studying new materials with unusual properties, such as novel magnetism or unconventional superconductivity.
In addition to the fundamental interest in discovering new states, there is great potential for new technological applications in the future, according to Lee.
Doostan’s research centers on developing scalable computational techniques for uncertainty representation and propagation in complex engineering systems. To enhance the credibility of simulation tools and increase confidence in model predictions, Doostan and his group construct probabilistic approaches to characterize uncertainties and their impacts on model predictions.
One of Doostan’s research efforts will be to attempt to improve simulation-based prediction of failure mechanisms in lithium-ion batteries.
To be eligible for the DOE Early Career Research awards, researchers must have received their doctorates in the past 10 years and be untenured, tenure-track assistant or associate professors at U.S. academic institutions or full-time employees at DOE laboratories. The three CU-Boulder faculty winners in 2011 were selected from a pool of more than 1,000 applicants, as were CU-Boulder’s 2010 winners.
The four 2010 recipients from CU-Boulder were Michael Hermele, Alysia Marino and Tobin Munsat of the department of physics and Arthi Jayaraman of the department of chemical and biological engineering.
There was one other DOE Early Career Award winner from Colorado in 2011 — Zhigang Wu from the Colorado School of Mines, who will be studying quantum mechanical simulations of complex nanostructures for photovoltaic applications.
For more information on the DOE awards go to http://science.energy.gov/news/in-the-news/2011/05-06-11/.