HELICOPTERS began dropping two tons of seeds this week on Brazil’s Atlantic Forest, which has been reduced by land speculation, and some of the world’s worst airborne pollution, to five per cent of its size 20 years ago.
The forest once covered vast tracts of eastern Brazil, and rivalled the Amazon in its unique biological riches.
The destruction of the forest, part of which runs along the coastal mountain range between Brazil’s two most populous cities, Rio de Janeiro and Sao Paulo, has become a catalyst for a fast-growing environmental movement among affluent Brazilians. The Sao Paulo state government, under pressure from the movement, launched Operation Re-vegetation. It plans to restore part of the pollution-damaged rainforest in Serra do Mar, a steep escarpment which separates the city of Sao Paulo, with a 16 milli on population, from the sea.
The seeds, collected from the forest, are to be sprayed over 9.4 square miles of barren hillside.
The de-forested areas were caused by years of pollution from industry in Cubatao, 35 miles from Sao Paulo.
Brazilian scientists warned 10 years ago that Cubatao’s uncurbed industrial waste had turned it into the most polluted area in the world.
In 1984, 236 tons of particles were belched into the air daily, in addition to gases and liquid effluents.
The local population suffered from chronic respiratory ailments, and acid rain slowly poisoned the once-lush rainforest.
A clean-up programme has succeeded in reducing pollution to 70 tons a day. But the scars on the hillside remain, causing landslides each rainy season.
The 300 million seeds are from faster-growing native forest trees, shrubs and ferns that tests show provide the basic cover needed to enable slower-growing hardwood species to take root over the next few decades.
The denuded regions of hillside were difficult to reach on foot. Planting the seeds by air also provided logistical problems. The seeds were powder-like and would have blown away.
Engineers from Sao Paulo University, however, devised a method for airborne drops.
They encased the seeds in gelatinous pellets the size of frog spawn. The pellets permit germination, and are heavy enough to fall to earth and stay there.
Laura Petti, director of programme and mobilisation development at the Sao Paulo State Environmental Control Department, said: “We believe this represents a significant advance in re-forestation techniques”.
The seed pellet is an adaptation of a locally-developed method originally used for encapsulating yeast. Mixed with sugar-cane juice, the yeast pellets speed up the fermentation process in the production of sugar-cane alcohol fuel.