COEUR D'ALENE, Idaho (AP) - Budget cuts to the U.S. Forest Service could hurt efforts to save a dying northern Idaho tree that is a critical food source for grizzly bears, birds and other forest animals.

The whitebark pine has been disappearing during the last 100 years because of an exotic fungus, hungry beetles and wildfire suppression, leaving only a few stands in the Selkirk Mountains. Nearly 90 percent of the whitebark pines in the region have been killed by white pine blister rust and mountain pine beetle infestations, mostly in northern Idaho and northwest Montana.

Local rangers and researchers have been working to save the tree, but federal budget cuts could serve as another obstacle for the tree's restoration. About $50,000 used to help save the dying trees has been left out of the U.S. Forest Service's budget.

Rangers had used the funding to grow new seedlings, research and to protect them from other plants and animals. Now northern Idaho rangers are looking for funding elsewhere to save the dying trees.

"The tree has just been knocked back so far. We're just trying to give it a helping hand," Bonners Ferry District Ranger Mike Herrin told The Spokesman-Review newspaper in Spokane, Wash. "Whether it has fur, scales, feathers, needles or leaves, it's just part of our job to maintain those species on the landscape."

Grizzly bears west of the continental divide depend on seeds in the trees' cones for about 40 percent of their diet. The seeds are a rich source of fat, protein and carbohydrates and readily available for bears emerging from hibernation in the spring, said Robert Keane, a research ecologist with the Forest Service in Missoula, Mont.

Scientists have also noted that the trees' decline may be a reason for the decline in the bears in Idaho.

The trees began dwindling in the 1910s with the introduction of blister rust, and were hit harder in the late 1990s when mountain pine beetle populations exploded and began chewing through surviving stands in the northern Rockies.

"It's declined so much in the last three to four decades, we really don't know what effect that had on grizzly bears. There's no telling how many bears inhabited those ridgetops when we had mature whitebark pine," Keane said.

The Selkirk Mountains northwest of Bonners Ferry have one of region's largest stand of trees.

Last summer the Forest Service began a three-year restoration project on stands in northern Idaho. They began cutting back competing tree species and conducting prescribed burns on 1,700 acres with the healthiest trees. They've also been collecting samples to see which trees may be resistant to the blister rust.

It's been slow work trying to boost the tree's numbers.

"Whitebark pine takes 60 years (to bear seeds), and it doesn't reach maximum cone bearing age until 250 years," Keane said. "We're looking at decades or maybe centuries before we see any results."

Dave Foushee, a tree improvement horticulturist with the Forest Service in Coeur d'Alene, has taken seeds from the 110 remaining wild parent trees and placed them in a greenhouse to ensure maximum survival.

He has at least 2,000 seedlings in the nursery as well as a fenced irrigated plot of propagated trees near Coeur' d'Alene. But his plot has also fallen victim to budget cuts, and he will now only get $1,000 to maintain the trees.

Phil Houg, president of the Sandpoint chapter of the Idaho Native Plant Society, said he is frustrated that funding is being cut for the program while money is still being provided for timber harvests and fuel reduction projects.

"It's a shame that the part of forest health that still gets funded is the part that cuts trees," said Hough, of Sagle, Idaho. "These trees occupy such an important niche of the environment."