海角大神

Paul Mankiewicz, a biologist, botanist, and erstwhile philosopher, has a vision for New York City. He calls it 鈥渮ero discharge鈥�: Not a drop of water should escape from the city without first making something grow.

Rainwater should be caught and used to cultivate greenery. 鈥淕ray water鈥� from showers, baths, and sinks should irrigate rooftop gardens. Trees dotting streets are good, but a belt of grasses and shrubs lining roadways would better catch and utilize runoff. Restored wetlands around the city would filter any water that escapes. All water entering the city should pass through a natural system on its way out.

鈥淲hat you have to do is bring the land to life,鈥� he says. 鈥淥ur footprint is not an abode for life. It鈥檚 the opposite; it鈥檚 sterile.鈥�

Mr. Mankiewicz, executive director of the Gaia Institute in New York and treasurer of the city鈥檚 Soil and Water Conservation District, has designed ecosystems for 30 years. He had a hand in the city鈥檚 very first 鈥済reen streets,鈥� patches of greenery sprouting up alongside roadways in recent years, and the Bronx鈥檚 first green roof.

Now he鈥檚 working with the city on a pilot project to restore oysters and mussels, keystone species, to city waterways. His guiding principle: Living systems can achieve naturally what humans endeavor to do artificially. Dirt can hold water and sequester heavy metals. Soil microbes and plant roots 鈥� 鈥渢he symbiosis that runs the terrestrial biosphere,鈥� he says 鈥� can digest the carbon-based molecules that collect in the average city gutter.

鈥淵ou have to rethink the permeable and impermeable,鈥� he says.

Beneath every square meter of soil run 15 to 20 miles of fine plant roots and perhaps 10,000 miles of filament-like fungal roots. Between 10 million and 10 billion microbes inhabit each cubic centimeter of soil. The right kind could decompose motor oil and gasoline, which are common in urban runoff. A cubic centimeter of humus, the fine, dark grains in soil, contains 2,000 square meters of surface area that binds to toxic heavy metals, like mercury.

Standing beside a 300-square-foot Bronx green street he helped design, Mankiewicz expounds on the value of living soil. Normally, the city has to treat runoff before releasing it into waterways. But this patch of green could absorb much of the 50,000 gallons of runoff generated here yearly. (Soil sensors will measure just how much.) Multiply that by some 2,000 green streets now in existence, and the result is some 100 million gallons of water not going down storm grates.

Over the years, Man颅kie颅wicz has em颅颅phasized the critical role of simple dirt, says Robert Alpern, an adviser in the city鈥檚 Department of Environmental Protection under former mayor David Dinkins: 鈥淗is major contribution has been to sensitize everybody in the bureaucracies to the potential of soils as a filtration and infiltration medium for storm water.鈥�

On St. Simon Stock Elementary School鈥檚 rooftop garden (finished in 2005), Mankiewicz explains the greatest hurdle to greening the city鈥檚 35 square miles of rooftops: The average cubic foot of dirt weighs between 100 and 120 pounds, around three times the load for which most roofs are engineered.

So he designed his own soil, substituting ground polystyrene (Styrofoam) for much heavier sand and clay. The result, patented as GaiaSoil, weighs 10 pounds per cubic foot and can hold twice its weight in water. The next problem: New York gets about 40 inches of rain yearly, but it doesn鈥檛 come evenly. A recent dry spell has left some of the Little Blue Stems, one of perhaps 25 native species atop St. Simon鈥檚 roof, looking forlorn.

He notes the nearby boy鈥檚 bathroom. City dwellers pay $2 per 100 cubic feet of water, and $3 to treat it. Why not save $3? Gray water from the sink could be fed to the garden via solar-powered pump. He has to convince the city it鈥檚 safe first. 鈥淚 want it so that people can build green roofs without the Department of Health worrying about it,鈥� he says.

Mankiewicz grew up Bloomfield, N.J. When he was young, Bloomfield farmers grew vegetables to sell in New York City. He himself sold tomatoes from his mother鈥檚 garden door-to-door. But urban sprawl eventually did away with the fields. 鈥淎ll the areas I grew up with that were beautiful were paved over,鈥� he says.

He earned a BA in philosophy from the New School for Social Research and a PhD in biology from City University of New York, among other degrees. In the 1980s, he spent lots of time at St. John the Divine, an Episcopal cathedral in Morningside Heights and a hotbed of environmental thinking.

James Parks Morton, sometimes called 鈥渢he green dean,鈥� presided over and encouraged the religious-environmentalist ferment for 25 years, ending in 1997. He recalls one project in particular: Inside a bay of the soaring gothic cathedral, by some accounts the world鈥檚 largest, Mankiewicz constructed a living model of the Hudson River ecosystem: several 20-foot-long tanks filled with fish, 鈥渧arious green stuff,鈥� and blue crabs.

鈥淚t was incredible, people saying, 鈥楳y God, in a church?鈥� 鈥� recalls Mr. Morton. 鈥淭hat was the point, to say that [the environment] is a deeply important, religious concern.鈥�

In the 1980s, Mankiewicz itched to apply his ideas on ecosystem design to the real world. 鈥淧eople were saying, 鈥榠nteresting idea,鈥� but no one was doing anything,鈥� he says. So in 1995, he incorporated the Gaia Institute, a nonprofit. 鈥淣othing was going to change, otherwise,鈥� he says.

It was an unusual move, says Dominick Basile, Mankiewicz鈥檚 PhD adviser at Lehman College in the Bronx. Most biologists choose the reliable paycheck of research or academia. But Mankiewicz and his wife, Julie 鈥� both of whom Dr. Basile describes as 鈥渂rilliant鈥� and 鈥渄edicated鈥� 鈥� chose to 鈥渟pread the gospel鈥� of biology. 鈥淚 really worried about them,鈥� he says. 鈥淭hey鈥檝e made some considerable material sacrifices.鈥�

Says Mankiewicz: 鈥淚f you want quick money, never get into the green-roof business.鈥� For 25 years, the overriding problem was lack of interest from on high. City officials favored a hard engineering approach 鈥� chemicals and machinery 鈥� to solve issues like storm water runoff. Now that鈥檚 changing. 鈥淧eople are just [now] getting it,鈥� he says.

The city now has 2,300 green streets, a program begun under mayor Rudolph Giuliani in the 1990s. Mayor Michael Bloomberg has pledged to surpass 3,000 by 2017. MillionTreesNYC aims to plant
1 million more trees throughout the city in coming years. (The current tree census: 592,130.) It鈥檚 all inching the city closer to Mankiewicz鈥檚 鈥渮ero discharge鈥� dream. 鈥淚t would change the local climate,鈥� he says, 鈥渁nd that would be magnificent.鈥�