Turning Dumps Into Forests
January 23, 2002
Working at various landfills and toxic-waste pits around the nation, ecologists are experimenting with turning them into scrub forests -- replete with trees, shrubs and flowers. So far, their efforts appear promising.
One such site is the Fresh Kills landfill on New York's Staten Island, which has been a repository of New York City's garbage since the 1940s. There, refuse has been compacted into four mounds nearly 200 feet high.
Over the past nine years, Rutgers University ecology professor Steve Handel and his teams have been concentrating on two mounds and turning them into groves of hackberry, crab apple and mulberry trees.
- The process first involves placing a layer of clay or plastic liner over the compacted trash, then covering it with a layer of sand or gravel.
- A thin layer of top soil is then put in place -- with an additional two feet to be added later in certain areas to accommodate the roots of larger trees -- and grass seed is sown.
- Trees native to the area are introduced -- and as their shade increases grass and reed species die out, and birds bring in diverse seeds.
- Insects, reptiles and mammals -- which also play a part in the ecological process -- are drawn to the area.
Nine years after planting, the vegetation prevents water from entering the garbage below -- helping protect the ground water from chemicals leaking from the garbage.
Source: Jim Carlton, "Where Trash Reigned, Trees Sprout," Wall Street Journal, January 23, 2002.
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