Yosemite's largest trees vanishing

MARIPOSA, Calif., May 22 (UPI) -- Climate change appears to be taking its toll on the oldest and largest firs and pines in California's Yosemite National Park, researchers said.

The number of large-diameter trees fell by 24 percent between the 1930s and 1990s in all types of forests in Yosemite, said James Lutz of the University of Washington in Seattle.

"Yosemite is one of the most protected places in the (United States). If the declines are occurring here, the situation is unlikely to be better in less protected forests," Lutz told the BBC in a story published Friday.

The decline appears linked to higher temperatures and not enough water, said Lutz and his UW research partner, Jerry Franklin.

The older, larger trees, including white firs, lodgepole pines and Jeffrey pines, are key to forest health because their canopies protect and nourish unique habitats for plants and animals.

"These large, old trees have lived centuries and experienced many dry and wet periods," Lutz said. "So it is quite a surprise that recent conditions are such that these long-term survivors have been affected."