Steven Handel stands at the edge of what is probably the largest pile of garbage humanity has ever created. The Fresh Kills Landfill on Staten Island, New York, covers 3.5 square miles. Its four large mounds, towering up to 225 feet high, are visible from outer space. Locals fought for years to shut down the landfill, decrying the odors, the risks to public health, and the way their borough had become the dumping ground for the city's 8 million residents. Finally closed in March 2001, Fresh Kills was reopened six months later to accept the debris from the World Trade Center.

From landfill to landscape: Thanks to the work of Professor Handel (top) and his students, the Fresh Kills site is now home to goldenrod (bottom left), late-flowering boneset (bottom right), and other native plants.

"It's hell on Earth, isn't it?" Handel says as we look north past a down-at-the-heels shopping center, a four-lane highway, a tank farm, and a power plant. In the distance, the rusting cantilevered I beams of the Goethals Bridge connect Staten Island to the factories and warehouses of Elizabeth, New Jersey, and beyond. Stray bits of litter swirl in the wind. But Handel, a professor of ecology at Rutgers University, is smiling. "I feel blessed," he says, "because I can see what this will be like."

The Big Apple's new park (foreground) will combine with adjacent woodlands to form a natural oasis just outside Manhattan.

In 20 years or so, Handel predicts, the now-closed landfill and its surrounding area will metamorphose into a 2,200-acre mosaic of meadows, scrub forests, and saltwater marshes, enjoyed by hikers, kayakers, and other nature lovers. Only about 50 percent of the site's acreage was actually used for trash disposal; much of the rest of Fresh Kills (whose name comes from the Dutch word for brook or channel, kil) retains its original character: a tidal wetland fed by freshwater springs and streams. Its garbage layers contained under a cap of plastic or heavy clay, new life will sprout in soil added above. "Someday Fresh Kills is going to be three times bigger than Central Park," he says. "It's going to be a destination, not a place to avoid and make fun of."

As director of the Center for Urban Restoration Ecology, a joint effort between Rutgers and the Brooklyn Botanic Garden, Handel has the knowledge to make his vision a reality. Founded in 2000, CURE is the nation's first cadre of scientists devoted to studying how urbanization affects ecosystems and ecological processes. Practically, that means figuring out what it would take to restore abandoned landfills, contaminated industrial sites, and other blighted landscapes to thriving, productive habitats.

The idea of nurturing nature in such unlikely places isn't new. Over the past two decades, alpine wildflower fields have been restored on ski runs in Davos, Switzerland. (The summer flowers stabilize the slopes and draw off-season tourists.) A defunct landfill in Liverpool has been transformed into a public park. In Australia, old mine sites are being revived with native shrubs. But the science of urban restoration—some call it "reconciliation ecology" to stress the idea of peace between people and nature—is still developing. To Handel, it's a field that can't mature fast enough. "Most Americans live in urban areas," he explains. "Nature is not just in Yosemite National Park. It's here, in the city." Sometime in this decade, Handel adds, the rest of humanity will become a largely urban species. Around the world, more people will live in cities than in countrysides. We can't bring back the forest primeval, but we can restore bits of urban land that provide valuable habitat for migrating birds and other animals, help clean the air, and stabilize the soil. These pockets of nature will offer rest and rejuvenation to harried city dwellers. As a bonus, doing this will be cheaper than maintaining lawns, channelizing streams, or designing parks in traditional ways. Since restored landscapes filter water, reduce damage from invasive species, and perform other valuable ecosystem services, they're also often less costly than leaving things alone.

WHILE OTHER ECOLOGISTS trek through rainforests or deserts, Handel and his colleagues explore abandoned manufacturing sites, scraps of leftover forest, and contaminated wetlands. Instead of pristine systems, they're looking at ecological puzzles: What plants are growing in our cities, and how are they evolving? Which native species would thrive if reintroduced into changed landscapes? How could these new ecosystems be made self-sustainable? "This is a chance to ask interesting new questions, to make an impact," Handel says.

Handel came to these questions almost by accident. As a graduate student at Cornell University and then a professor at Yale, he studied Australian orchids and seed-dispersal and pollination systems. After moving to Rutgers in 1985, he regularly led plant-ecology field trips to the urban marshes west of Manhattan. Year after year, Handel noticed the barrenness of the old Meadowlands landfill there, south of Giants Stadium, next to the ever-jammed New Jersey Turnpike. Covered with dirt when it closed in the 1970s, the site was an ecological failure. The natural progression from grassland to shrubs and then forest didn't happen. The land sat dormant. "I started thinking about how we could restore that landscape, and other small, human-dominated landscapes," he says. "Then I realized, 'Hey, that's most of the world.'"

Handel theorized that the interstate highways and factories surrounding the Meadowlands site prevented seeds, birds, and small mammals from reaching the retired landfill. It was an island. So Handel and his Rutgers team decided to jump-start nature. They augmented the soil with 20,000 cubic yards of municipal compost to make up for the lack of helpful microbial activity and planted trees and shrubs. Now a young, dense woodland grows on the site.

Eventually, Handel's work attracted the attention of New York City officials worried about a few small trees that had sprouted on a capped mound at Fresh Kills. Would the tree roots puncture the cap, perhaps releasing the pressurized methane gas that forms when organic materials decay or allowing poisons from the garbage to seep into New York Harbor? (Most methane is pumped out of landfills, though some of it can leak and drive oxygen from the soil—yet another hurdle for new plants to overcome.) "The engineers were thinking of tree roots that push up sidewalks," Handel says. "But we found that the roots just turned when they hit the cap. Two feet of soil is enough to support a healthy forest." So why not plant one over Fresh Kills? "Landscaping the whole site would cost a king's ransom," Handel says. "We wanted to find out if we could enlist the birds as landscape architects." With help from the Brooklyn Botanic Garden, Handel and his students researched what the historic ecosystems had been on the Fresh Kills site. They collected seeds and enlisted native-plant nurseries to propagate them. In 1992 the team planted 20 clusters of native trees and shrubs: hackberry, shadblow, sumac, beach plum, blackberry, pasture rose, and blueberry. Soon bees, moths, and small mammals from isolated areas near the landfill started to use the clusters. Within three years, there were 50 species of bees, as many as in a natural setting. Birds came, ate the fruit and berries, and dropped more seeds. Mulberry, sassafras, Virginia creeper, and more than a dozen other woody species appeared.

Yet not all the results were rosy. Some seedlings had trouble in the poor soil, and the smaller clusters struggled. For the plan to work on a large scale, the soil will have to be enriched and large clusters established, Handel says. The CURE team will also have to use the new plant varieties they're developing specifically for harsh urban environments. In New York City, for example, water running over all the concrete puts more calcium in the exposed soil that's left, changing the acidic environment preferred by natives like blueberries, cranberries, and laurels. Non-native earthworms speed the decay of leaf litter and alter the soil. Microbes that rot organic matter and help plants absorb nutrients and water don't usually survive at normal levels in the city. Aquatic systems are completely transformed, air is polluted, and temperatures run high. We've changed our planet so much that nature can't take care of itself, at least not where people live, without a helping hand.

WORD IS SPREADING about CURE's efforts to rehabilitate these troubled areas, and Handel fields frequent calls from land managers around the country. One came from Concord, Massachusetts, where—unbelievably—the town aldermen in the 1950s had sited a landfill across the road from Walden Pond. Today a local nonprofit is trying to re-create the landscape Henry David Thoreau immortalized in print. Thoreau's famous declaration "In wildness is the preservation of the world" helped popularize the idea that nature is better off left alone. "Nowadays almost all man's improvements, so called . . . simply deform the landscape, and make it more and more tame and cheap," he wrote in his seminal essay "Walking." Those sentiments are still common among environmentalists, but they haven't stopped Handel from recommending intervention at places like Walden Pond and Fresh Kills.

On a cool day in early summer, as we turn our backs on the industrial nightmare near Fresh Kills and tune out the drone of the highway, it's almost possible to imagine we're in a bit of native hackberry forest. Red-winged blackbirds call to each other. Cabbage white butterflies flutter by. "This is the real thing!" Handel exults as we stop at the edge of a thicket surrounded by mounds of pink wild roses. "There's enough shade to kill off the grass. There's a real center, a place for birds to nest. In the small patches, leaves blow away; here the leaves stay and make the soil rich. It's spreading nicely. Look! Here's a baby hackberry that's sprouted from seed. How could you tell that it's a landfill?"

Heather Millar has written about environmental issues for Smithsonian, the Atlantic Monthly, BusinessWeek, and other publications.

Photos:Nick Romanenko/Rutgers University