Tag Archives: snowmelt

CU-led Mountain Forest Study Shows Vulnerability to Climate Change

A new University of Colorado Boulder-led study that ties forest “greenness” in the western United States to fluctuating year-to-year snowpack indicates mid-elevation mountain ecosystems are most sensitive to rising temperatures and changes in precipitation and snowmelt.

Led by CU-Boulder researcher Ernesto Trujillo and Assistant Professor Noah Molotch, the study team used the data — including satellite images and ground measurements — to identify the threshold where mid-level forests sustained primarily by moisture change to higher-elevation forests sustained primarily by sunlight and temperature. Being able to identify this “tipping point” is important because it is in the mid-level forests — at altitudes from roughly 6,500 to 8,000 feet — where many people live and play in the West and which are associated with increasing wildfires, beetle outbreaks and increased tree mortality, said Molotch. (more…)

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Early Spring Drives Butterfly Population Declines

“Ahead-of-time” snowmelt triggers chains of events in the Mormon Fritillary butterfly

Early snowmelt caused by climate change in the Colorado Rocky Mountains snowballs into two chains of events: a decrease in the number of flowers, which, in turn, decreases available nectar. The result is decline in a population of the Mormon Fritillary butterfly, Speyeria mormonia.

Using long-term data on date of snowmelt, butterfly population sizes and flower numbers at the Rocky Mountain Biological Laboratory, Carol Boggs, a biologist at Stanford University, and colleagues uncovered multiple effects of early snowmelt on the growth rate of an insect population. (more…)

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‘Mountain Pine Beetle Activity May Impact Snow Accumulation And Melt’

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. (more…)

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Desert Dust Reduces Colorado River Flow

Dark-colored dust that settles on snow in the Upper Colorado River Basin makes the snow melt early and robs the Colorado River of about 5 percent of its water each year, says a new study co-authored by researchers from the University of Colorado at Boulder-based Cooperative Institute for Research in Environmental Sciences, or CIRES.

(more…)

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