On one side of the property line, a new forest is taking root - a glassy-green sea of waist-high pine planted by a timber company after a massive wildfire swept through six years ago.

On the other side, on public land managed by the Lassen National Forest, dense mats of brush cling to a landscape dominated by charred dead trees, some standing, others not.

"Nobody on the Lassen is proud of that land line," said Duane Nelson, who manages reforestation for the Forest Service in California. "We actually refer to it as our wall of shame."

Reforestation - the planting and natural regeneration of trees - is the most critical part of forest management. But across the West, vast parcels of Forest Service land scorched by increasingly catastrophic wildfires have not been replanted. The consequences may linger for centuries.

Imagine a Sierra Nevada that yields not gin-clear snowmelt but coffee-colored torrents from eroding canyons. Imagine shrub fields that stretch for miles, so dense that even birds and backpackers avoid them. That is the future Doug Leisz - a former associate chief for the Forest Service - envisions unless the agency replants more quickly.

"It's an extremely serious matter," said Leisz, 80, who lives near Placerville. "Our forests are too precious to lose this way."

Large fires across the West since 2000 have sparked enormous concern in Congress, state legislatures and forest communities. They have led to huge new investments in firefighting and prevention. But far fewer dollars have been routed to the tricky business that follows a fire: getting the trees growing again.

The scope of the challenge can be viewed not only from lonesome backcountry roads, but also in a handful of government reports, including three by the U.S. Government Accountability Office. Among their findings:

* While the Forest Service spends 40 percent of its $4.5 billion budget on fire, only a tiny fraction - about one percent - goes toward reforestation.

* As wildfire's footprint grows - this year a record 9 million acres have burned - the agency's reforestation backlog grows, too. In 2004, the most recent year for which data is available, 900,000 acres of Forest Service terrain slated for planting was left unplanted, up from 722,000 in 2000.

* Even where trees are planted, the agency often has no money to care for them. As a result, young stands grow into shadowy thickets where dead limbs dangle like wicks into brush - an invitation to more fire. Nationwide, 2 million acres of planted ground need thinning, an area three times the size of Yosemite National Park.

"I'm disappointed. I'm saddened. I'm frustrated," said Gil Driscoll, a retired mechanical engineer who lives near one overcrowded plantation in the Plumas National Forest.

This is not the first time the Forest Service has faced a reforestation backlog. In the '70s, an even bigger swath of land - about 3 million acres - needed replanting, largely because of logging.

Pressured by Congress, the Forest Service chipped away at that backlog, paying the bill not with tax dollars but with money made from selling timber. Much of the backlog evaporated.

In those days, "reforestation could be planned and scheduled," Joel Holstrop, deputy chief of the Forest Service, told Congress last year. "Much of this predictability is lost when the principal causal agent creating reforestation needs" is wildfire.

And wildfire - fed by a massive buildup of woody debris, the legacy of a century of firefighting - is gobbling up more terrain than ever, and burning in destructive ways. Big, old, seed-producing pines that have weathered fire for centuries are dying in today's super-novas.

Making things worse, the timber industry dollars that paid for reforestation in the past have diminished as environmental lawsuits throttle the sale of Forest Service timber.

The upshot: Forest Service terrain that needs replanting is growing rapidly, but money for reforestation is not.

"This is a swing back to the dark side," said Leisz, the retired Forest Service associate chief. "The backlog is getting bigger. It's growing like a cancer."

Of course, others dream of a different future in which the mountains recover naturally, over centuries, without the road-building and post-fire salvage logging that Forest Service officials say is needed to speed - and help pay for - reforestation.

"Salvage logging adds insult to injury, especially after a severe fire," said Linda Blum, a member of the Quincy Library Group, formed by citizens to strike a balance between logging and protecting the environment.

Yet there are few better places to see the consequences of the agency's failure to replant than in the expanse of brush and charred timber in the upper reaches of the Feather River, where the Storrie fire blackened 56,000 acres in 2000.

Obstacles to reforestation were numerous. Money was tight. In the Lassen National Forest, where 27,000 acres had burned, 21,000 acres were set aside as a natural area. They could not be touched. But Lassen officials determined that 1,100 acres could be replanted and planned to pay for it by logging trees killed in the blaze.

So began more than a year of planning - required by the National Environmental Policy Act and other laws. Then, in 2002, five environmental groups appealed, alleging the Storrie restoration project would hurt the area by damaging water quality and spotted owl habitat.

In August 2002, a Forest Service appeals officer ruled the project could go ahead. By then, the trees were starting to rot. Timber companies showed little interest. Eventually, only 234 acres were replanted at a cost of $266,000. And the job was paid for not with salvage revenue, but with tax dollars.

Bush administration officials are backing a House bill aimed at speeding up the process. "If we have to hug every tree and carry it out with six pallbearers, restoration work is going to become prohibitively expensive," said Mark Rey, undersecretary for natural resources and the environment at the U.S. Department of Agriculture, which oversees the Forest Service.

But the GAO's 2005 report said the Forest Service could not quantify those costs: "Data are not readily available to show how common it is for salvage sales to delay reforestation projects or the extent to which revenues for salvage timber sales have declined, and why."

Elsewhere, skepticism runs deep. "The blacker the timber, the greener the dollars," said Blum, the Quincy conservationist. She believes that natural processes work best.

"We shouldn't be trying to rush a piece of land right back into a mature forest," she said. Letting trees decay, she said attracts small mammals that spread seed, accelerating recovery. Brush fields provide habitat for fox sparrows and other birds.

Such a natural recovery, takes time, however.

The Forest Service's Nelson has walked through the area and seen "seedless landscapes" - scorched ground where no seedlings sprout.

"Those areas, they had been forests before and it's going to be perhaps centuries before they're forests again," Nelson said. "Is that really what we want?"

This much is certain: there is no famine of trees on 3,200 acres of nearby land managed by W.M. Beaty and Associates. After the fire, the company logged most of the big, valuable trees and used the proceeds to plant nearly a million new ones.

Today, young conifers sway in the wind next door to the government's ghost forest of decaying trees and brush. Recently, Beaty forester Bob Rynearson walked along the company's property line and glanced at the Forest Service side. "It just seems like a waste," he said.