Phytobarricading Agent Orange Contamination in Vietnam
Phung Tuu Boi, is a forester and director of the Center for Assistance in Nature Conservation and Community Development. During the Vietnam War a field in Dong Son served as an American Special Forces air base, and while the soldiers departed long ago, dioxin from the Agent Orange that they stored and sprayed here lingers still. Boi has dedicated his career to repairing the ecological damage left by what people in Vietnam call the American War.
When Boi began working in 1975, he found an ecosystem decimated by war. Aerial spraying of defoliants had destroyed large swaths of forest. Without live roots to anchor the soil, monsoon rains washed away the topsoil and its nutrients, allowing invasive grasses to take over and prevent forest regeneration. A botanist by training, Boi's initial goal was to reforest the denuded land and he enlisted the help of the Australian acacia tree. The acacia grows up to six and a half feet per year and, after five years, can be harvested by indigenous people to make paper and furniture. The tree also improves the soil and quickly provides the canopy that trees need to take root.
Boi has used the acacia tree to reforest thousands of hectares in central Vietnam. Emboldened by these successes, he has applied his botanical model of remediation to tackle a far more difficult problem in Dong Son. Dioxin takes decades to break down. Remediating the sites would require millions of dollars, and when it comes to financing, the more heavily populated hot spots in Danang and Bien Hoa take precedence. If the Dong Son hot spot were in New Jersey or Florida, a barbed wire fence and a warning might be enough to deter people from entering the area, but such solutions break down in the face of extreme poverty. “You put up a fence, and the people are so poor that anything they can get their hands on, they'll take down and use,” said Wayne Dwernychuk, an environmental scientist who did studies for Hatfield Consultants.
Boi has developed a low-tech solution to overcome these problems: a fence made of trees covered with cactus-sharp needles to deter humans and animals alike. Boi hopes this so-called green fence will not only discourage trespassers, but also provide them with an economic incentive to leave the barrier intact. Once mature, the trees he has chosen to make up the fence, Gleditschia australis, produce a fruit that residents can sell to make soaps and medicines. The tree is a type of honey locust, disease and insect resistant. Thorns and soft wood should deter residents from cutting it down for firewood.
While the initial fence failed to work due to herbivore predation of the small seedlings, Boi plans to modify the next planting. He will amend the soil with fertilizer then plant larger seedlings, and in addition to the original locust fence, he will add rows of acacia on either side to create a three-layer fence. The acacia will help protect the locust trees, improve the soil and provide another cash crop for residents. Boi needs $20,000 more to finish the fence. He has received no government financing and has resorted to spending his own money to keep the project alive. (International Herald Tribune, 9/18/07).
