A dump no more.

Innovative ideas applied in a harsh environment are restoring life to the planet's largest landfill.

Picture a landfill. Now picture a plan to return it to its natural state - not careful groupings of trees like you might see in a park, but actual ecosystems that thrive on their own and provide a place for humans to enjoy and wildlife to live. As one of the architects of a project to do just that on Staten Island, New York's Fresh Kills - the world's largest landfall, I believe that idea is not only possible - it's happening there right now.

In our cities, counteracting concrete with greenery is a priority. What might be considered an unlikely option - closed landfalls, which are increasing in number around the country - offer space-starved urban areas an ideal solution: open space virtually guaranteed to remain undeveloped. Reforesting would bring these sites back to their natural state and improve the local environment. In some states, though, the fear that roots would break through the "clay cap" that seals in water-borne pollutants has kept trees off closed dumps. But demonstration plantings on six acres of Fresh Kills may help dispel those worries.

The Fresh Kills Project was borne of necessity: Once it is completely closed, maintaining a "lawn" of grass across its 2,400 acres - mowing, fertilizing, and watering - was estimated to cost more than $20 million over a 30-year period. So the city Sanitation Department, in search of alternatives, developed a series of test plots and experiments, including one to re-establish native woodland communities.

The designers - myself and horticulturist John McLaughlin - chose a remote northeast corner bordering a federally protected salt marsh and set about mimicking coastal sites by creating dune-like slopes of compacted till soil. Then we began the arduous task of recreating the oak scrubforest, pine-oak forest, and ericaceous, or acid-loving, shrubland that existed before the landfill.

Eighteen woody native species were chosen to represent those habitats, and we worked with the city's Parks Department to rescue plants from other sites on Staten Island that were slated for development. It took two growing seasons to plant the three sites with about 3,000 shrubs, in small clusters of six to 12 plants each, and to plant 523 trees among the pine and oak dunes. Native perennial grasses and wildflowers were overseeded throughout the site. Oak, pitch pine, and beach plum joined perennial grasses and Indian nutgrass, native aster, and black-eyed Susans, among other wildflowers.

We also planted a meadow, reminiscent of Staten Island's eastern prairie, on 16 acres adjacent to the woodland. It's likely that grassland will end up as the dominant ecosystem on the landfall.

The first year is hardest on new trees, and the Fresh Kills site is a tough one. Conditions there are harsh and waterings are infrequent due to the impracticality of putting irrigation systems on such a remote site. The trees received minimal care: pruning, sing, anti-desiccant on the pines, and a heavy layer of mulch. But Rutgers University, hired to review the project, gave Fresh Kills the thumbs up. Previous surveys by university ecologists showed old landfalls to be best at growing weeds, even after 20 years. Our trees grew moderately well; shrubs did great.

But the most successful result was something I hadn't even anticipated. The trees planted on Fresh Kills provided much-needed perching sites, and the birds reciprocated by dispersing seeds, helping to replant other areas with "volunteer" trees. This "natural recruitment" boosted the number of woody species from 18 to 50, adding 14 different trees, 10 shrubs, and eight vines. Herbivores - voles, mice, and rabbits - were abundant, as were harriers and hawks.

Perhaps the best news coming from Fresh Kills: The clay cap has remained intact, unaffected by tree roots. The state Department of Environmental Conservation is now reviewing the question of roots and the clay cap, and I have sent a letter to the Environmental Protection Agency in hopes that it will endorse our demonstration project.

In the meantime, instances of re-treed landfills are becoming more frequent. On Long Island, a closed landfill cancelled its mowing contract and is letting nature - including volunteer trees - take its course. AMERICAN FORESTS' Global ReLeaf Forests program has regreened dumpsites in Oklahoma, Michigan, and Louisiana (see sidebar).

What's next for Fresh Kills? How about "habitat islands" where trees and shrubs would be planted in small islands over the whole landfill, allowing nature and birds to fill in the rest, just as they did on the test site. Fresh Kills could be a key link in creating the largest contiguous wildlife area in New York City.

Landfills can be repositories for threatened and endangered plants and trees, a way to preserve the gene pool and add diversity. We can also see Fresh Kills serving as a nursery for propagating blighted but beloved species such as the American chestnut and American elm as scientists search for disease-resistant hybrids.

Landfills have been dumping grounds for both trash and criticism. But as this project shows, they can be brought full circle to recreate natural communities that benefit not only humans but animals and the entire ecosystem.

RELATED ARTICLE: CREATING LANDFILL HABITATS

American Forests' Global ReLeaf Forests program has been turning trash into treasures by regreening closed landfills with trees on sites in Louisiana, North Dakota, and Oklahoma. In the first dump reforestation, in 1992, volunteers planted longleaf pine and mixed hardwoods near the town of Kentwood in Louisiana's Tangipahoa Parish. A year later, oaks and loblolly pine graced with landfills in the state's Caddo Parish, thanks to the Twin Valley Resource Conservation and Development Area (RC&D).

Last year, North Dakota schoolchildren received a lesson in ecology and stewardship by planting several hardwood species on a landfill there under the guidance of the Greater Grand Forks Arbor Day Committee. More recently, the Great Plains RC&D organized a restoration project that resulted in 61,000 mixed hardwood species being planted on five town landfills. Oklahoma-based Global ReLeaf partner United Design was the primarily funding source for the 290-acre project in western Oklahoma.

The question of what to do with closed landfills is being asked by localities all across the country. Reforesting seems like an ideal solution. For more information on donating to the Global ReLeaf Forests program or to learn about getting funding for a Global ReLeaf Forest, contact Bill Tikkala at AMERICAN FORESTS, PO Box 2000, Washington, DC 20013; 202/667-3300 ext. 204.

BILL TIKKALA

BILL YOUNG - director of the Fresh Kills Project, is a landscape architect in Wellington, Florida.