WILMINGTON, N.Y. - Whiteface Mountain is a tourist trap in the High Peaks of the Adirondacks.
It is the only mountaintop that can be reached by car. In the winter, it is a ski resort; in the summer, it is a mountain bike center.
As such, Whiteface is the only peak of the 46 highest Adirondack Mountains not designated as pristine wilderness.
But the threats facing Whiteface (elevation 4,670 feet) confront many of the more strictly protected peaks of the Adirondack Park, and some are coming from afar.
For nearly 40 years, researchers have used Whiteface as the peaks' living laboratory.
On its slopes, scientists have cataloged widespread tree death from acid rain, and more recently, high levels of smog and other air pollution.
And here, on many days, mountaintop visitors paying $8 a car to reach the summit have a view obscured by a haze that some scientists say has worsened in recent years and poses the newest pollution threat to the High Peaks' forests.
On Whiteface, at one of the few mountaintop monitoring sites in the country, scientists have found some of the most concentrated air pollution in the state, along with some of its gravest effects.
"The High Peaks make a good canary in a coal mine," said Kathleen Fallon Lambert, executive director of the Hubbard Brook Research Station at the University of New Hampshire. "They tend to be more sensitive. They tend to receive a lot of cloud water and fog."
So far, researchers atop Whiteface Mountain have found that cuts in air pollution required by the federal government a decade ago have helped the forests on the fragile mountaintops to heal. But most say more has to be done to preserve the forests well into the future.
"Unless we remove pollution from cloud water, eventually we could have a repeat," said Chris Eagar, an ecologist with the U.S. Forest Service in Durham, N.H., who edited the book Ecology and Decline of Red Spruce.
"But the trees won't die in our lifetime," he added.
Dedication to science
The monitoring station at the summit of Whiteface Mountain showcases the lengths some will go for science.
In summer, researchers climbing to reach their instruments risk being struck by lightning. In winter, they travel up the mountain in two-person sleds, dig through feet of snow and chip away icicles to get to their monitors.
The components of acid rain can be measured only at lodge level - a base about 1,990 feet up the mountainside. At the 4,670-foot summit station, rain can be horizontal.
"You have to be here to see what you're sampling against," said Doug Wolfe, operations manager for the State University of New York at Albany's Atmospheric Sciences Research Center station atop Whiteface. "The conditions are entirely different from what happens below."
At the lodge level, in a small clearing in the woods, sits a collection of trailers. Each one has a tower jutting into the sky and emits a dull hum from incessant air conditioning. Some are only big enough for a single scientist, monitoring equipment and a computer.
But they are capable of measuring pollution in the air every tenth of a second and sensitive enough to register a spike when a single car drives up the mountain.
Ken Demerjian, director of the Atmospheric Sciences Research Center, operates Whiteface with less than $300,000 in federal grants each year. The money pays for the equipment and subsidizes about 40 scientists who use Whiteface to study everything from air pollution to how clouds form.
Demerjian makes the 2 1/2 -hour drive to Whiteface at least once a week in a silver-gray sedan with Massachusetts vanity plates that read CLNAIR.
He has studied the chemistry of what's in air for so long that on any given day, as he leaves Interstate 87 to get to Whiteface, he can look at the hazy film that seems stuck on the mountains and break it down to its components.
Even his eyes look celestial - a brown pupil encircled by a thin blue ring.
"There's no major local pollution. It's all regional," he said on a recent trip. "A pollution episode is usually 2 to 3 days old."
The High Peaks' pollution problems start in the Ohio Valley, with its many coal-fired power plants, and are amplified by the city traffic of Toronto and Buffalo.
Wind catches what is emitted from the smokestacks and tailpipes and blows it east, carrying it toward the High Peaks at up to 50 mph. Once over the mountains it stops, hemmed in by high pressure.
As more pollution rolls in, concentrations of the gases that generate acid rain, ground-level ozone and small particles build over New York's tallest peaks, creating what Demerjian calls a "pond of pollution."
The bulk of it arrives at night, hours after factory shifts end and rush hours subside. That's when monitors on the summit record the highest levels of air pollution.
The plume then attacks the high-elevation forests of the Adirondack High Peaks from all sides.
"The forest acts as a sponge for air pollution," said Gary Lovett, a forest ecologist with the Institute of Ecosystem Studies in Millbrook.
Highly acidic clouds soak evergreen needles in an acid bath. As the tree breathes, the contaminants are sucked in.
Smog smothers the trees in a haze, short-circuiting photosynthesis - the process by which trees convert sunlight to energy.
And the tainted rainfall and snowfall seeps into soil, changing its chemistry and starving the trees at the roots.
By the mid-1980s, more than half of the red spruce and balsam fir trees on the upper slopes of the Adirondack High Peaks had succumbed to acid rain. In 1990, research on Santanoni, Seymour, Marshall, Skylight, Basin, Colvin and Nippletop mountains found 30 percent of the forest was still lifeless stalks.
Death makes its way up the slopes of Whiteface in ripples, dead trees forming gray waves in a sea of green forest.
Effects of acid rain
Despite the lingering effects of acid rain, there is rebirth in many places. On a recent trip up Mount Marcy, Pete Fish, a retired DEC forest ranger, looked around him and remembered the days when New York's highest peak was surrounded by the die-off.
"That whole thing was a massive thicket of white spars," said Fish, waving an outstretched hand slowly over the horizon as if trying to touch the tips of the trees.
More than a decade after the demise of the red spruce, researchers are still trying to figure out what it means for the future of the forest. Some scientists are cautiously saying that it looks as if the impact of acid rain is subsiding.
John J. Battles, an associate professor of forest community ecology at the University of California at Berkeley, travels across the country every two years to check on 60 plots of trees that he has measured and analyzed since the mid-1980s, at the height of the forest's death cycle.
"I'm interested in how this forest works," he said in a telephone interview. "What is the impact of having half of the dominant tree species die? Does a species decline lead to a decline of the forest?"
So far his results defy reason. While acid continues to fall on the Adirondacks - and at rather high levels compared with much of the rest of the country - this time around, the trees are holding on.
"It seems that the forest is recovering - that red spruce is no longer dying," Battles said. "What the trees are doing doesn't seem to fit with the environmental conditions."
Part of the reason for the rebound is attributed to reductions in air pollution phased in during the early 1990s as a result of amendments to the Clean Air Act.
Over the last decade, atmospheric sulfur has declined while nitrogen has remained relatively stable.
"What we have seen is effects of sulfur control. We can demonstrate the effect of sulfur controls in this region," said Demerjian. But "ozone and nitrogen ... we haven't controlled them significantly."
And nitrogen may be the linchpin to explaining how acid rain works in the Adirondacks and why recovery is sluggish.
Unlike sulfur, nitrogen is a nutrient that trees need to grow. The High Peaks' mountainsides just receive too much of it each year.
Let loose, nitrogen depletes other elements in the soil that are essential for a tree's nutrition. It is then converted by microbes within the forest floor into more acid.
"To a certain extent, we are going to continue to watch to see what's going on. What caused the problems with the trees was a change in soil chemistry," said Greg Lawrence, a hydrologist with the U.S. Geological Survey in Troy. "The young ones ... are growing under conditions of less nutrition."
Other theories to explain the recovery are more varied.
Some researchers think the climate has warmed, reducing the chance of winter injury. Others think the new generation of trees has inherited resilient genes that protect them from the effects of pollution.
It is what the scientists do not know that has them worried.
"This could just be a momentary pause," Battles said. "The risk is that we could see trees die again."
And it may not be because of acid rain.
The same species that fell victim to acid rain in the 1950s, '60s, and '70s - red spruce and balsam fir - are also the most susceptible to another pollutant on the Adirondack horizon: the smog that makes a pit stop in the region.
Research in laboratory settings has shown that ozone can disrupt a tree's ability to convert sunlight into energy even at lower levels. But not all scientists agree on whether it will have a severe effect on the woods.
Based on what is known now, Eagar suspects that when compared with acid rain, ozone will be a minor factor in the High Peaks and other Eastern forests.