FORT COLLINS, Colo., July 9 (UPI) -- U.S. scientists say global warming might have a greater influence on some plants' annual growth cycles than previously thought.
Researchers led by Heidi Steltzer of Colorado State University's Natural Resource Ecology Laboratory said their findings suggest accelerated snowmelt caused by desert dust blowing into mountainous areas changes how alpine plants respond to seasonal climate changes.
Current mountain dust levels in Colorado's alpine valleys are five times greater than they were before the mid-19th century, the scientists said.
"Human use of desert landscapes is linked to the life cycles of mountain plants, and changes the environmental cues that determine when alpine meadows will be in bloom, possibly increasing plants' sensitivity to global warming," said Jay Fein of the National Science Foundation, which partially funded the research.
With climate change, the warming and drying of the desert southwest is likely to result in even greater dust accumulation in surrounding mountains, the researchers said.
"Earlier snowmelt (caused) by desert dust depletes the natural water reservoirs of mountain snowpacks and in turn affects the delivery of water to urban and agricultural areas," said Tom Painter, director of the Snow Optics Laboratory at the University of Utah.
The study that included Chris Landry, director of the Center for Snow and Avalanche Studies in Silverton, Colo., appeared in last week's issue of the Proceedings of the National Academy of Sciences.
