WASHINGTON, D.C., APRIL 6, 2012As global temperatures rise, the most threatened ecosystems are those that depend on a season of snow and ice, scientists from the nation's Long Term Ecological Research (LTER) Network say."The vulnerability of cool, wet areas to climate change is striking," says Julia Jones, a lead author in a special issue of the journal BioScience released today featuring results from more than 30 years of LTER, a program of the National Science Foundation (NSF).
In semi-arid regions like the southwestern United States, mountain snowpacks are the dominant source of water for human consumption and irrigation. Research by Jones and her colleagues shows that as average temperatures increase in these snowy ecosystems, a significant amount of stream water is lost to the atmosphere. The study involves more than thirty years of data from 19 forested watersheds across the country. All of the study sites provide water to major agricultural areas and to medium and large cities.
But, like many long-term studies, this one revealed a surprise. Water flow only decreased in the research sites with winter snow and ice. Jones explains, "Streams in dry forested ecosystems seem more resilient to warming. These ecosystems conserve more water as the climate warms, keeping streamflow within expected bounds."
A range of factors can impact watersheds, from human influence past and present, to El Nio climate oscillations. "Long-term records are finally long enough to begin to separate the effects of each," Jones points out. "This research shows both the vulnerability and resilience of headwater streams. Such nuanced insights are crucial to effective management of public water supplies."
Surprising and transformative results are common in LTER, which comprises 26 sites in North America, Puerto Rico, the island of Moorea, and Antarctica. The network has amas
|Contact: Thomas O. McOwiti |
University of New Mexico, Long Term Ecological Research (LTER) Network