"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
|Contact: Evan Pugh|
University of Colorado at Boulder