Spring in the Rockies begins when the snowpack melts. But with the advent of global climate change, the snow is gone sooner. Research conducted on the regions wildflowers shows some plants are blooming less because of it.
David Inouye (University of Maryland) used data gathered in the Rockies from 1973 to the present to uncover the problem. Writing in the journal Ecology, he demonstrates that three flowers found in the Rockies are far more susceptible to late frost damage when the snow melts more quickly.
Inouye looked at three blossoms that are common to the famous mountain range. Larkspur (Delphinium barbeyi), holds its intense blue star-shaped, hooded blooms on thin-stemmed plants that can be anywhere from 3-6 feet tall. Aspen fleabane (Erigeron speciosus) is one of the most common asters to the region, and its small, purple daisy-like flowers have yellow centers. And aspen sunflowers (Helianthella quinquenervis) are well known for their startlingly bright yellow flowers which are often found in open, grassy areas.
Winter snow can be as deep as eight feet in the area where all three of these flowers grow, at 9,500 feet altitude, but the snow has been melting increasing early over the past decade because of a combination of lower snowfall and warmer springs. For the wildflower, earlier snowmelt results in an earlier growing season.
Once the snow is gone in the spring, the flowers begin to form buds and prepare to flower. But masses of cold air can still move through the region at night, causing frost as late as the month of June. The numbers indicate that frost events have increased in the past decade. From 1992 to 1998, on average 36.1 percent of the aspen sunflower buds were frosted. But for 1999-2000 the mean is 73.9 percent, and in only one year since 1998 have plants escaped all frost damage.
When those frost events occur, the long-lived plants do not die but are unable to produce flowers fo
|Contact: Nadine Lymn|
Ecological Society of America