SINCE the terrible drought of 1969, deforestation has been building to a crisis in Burkina Faso, a small West African nation barely south of the Sahara. In 1985, the year that Henri Ye left to work for a PhD in forestry at Duke University, Durham, N.C., the crisis hit. That year civil servants in the capital, Ouagadougou, spent an average of 20 percent of their salaries on firewood, the region's main fuel. Village women walked as far as 10 miles a day in the dusty countryside to gather wood for cooking fires. In the hot, arid north, the harmattan - a dry, dusty wind - whirled millions of tons of denuded soil into the advancing desert.
Mr. Ye, a forestry professor at the University of Ouagadougou, has been searching for the hardiest, fastest-growing tropical tree in the world.
Now he is returning with Gliricidia sepium.
Ye believes that the nitrogen-fixing Gliricidia, which grows 15 feet in five years and will sprout again from a stump, can play a major role in reforesting Burkina Faso. The silvery barked hardwood, indigenous to Central America, can grow from both seeds and cuttings. It can withstand the eight-month drought that is seasonal in West Africa.
``It is almost a weed,'' says Ye, noting that the tree is nearly impossible to kill. Branches - even the whole tree - can be cut for firewood without harming the prolific root system.
Moreover, Gliricidia leaves are palatable for domestic animals. And its roots have nodules that fix nitrogen in the soil, replenishing exhausted farmland. In Costa Rica and Nigeria, the tree is interplanted with crops as a natural fertilizer.
Ye spent the last three years studying the properties of hundreds of tropical trees. Supported by a $22,000 grant from the Rockefeller Foundation, he will take Gliricidia seeds from Nicaragua, Guatemala, Nigeria, and Kenya and develop a strain of the tree adapted to Burkina Faso's soil and climate.
An easygoing man who is fluent in English and French, as well as Bobo and Dioula, Ye has extensive plans for how the new strain of Gliricidia could be distributed in Burkina Faso. He envisions agricultural extension agents, foresters, and schoolchildren spreading seedlings and information.
The principal target of his outreach is farmers, who make up about 85 percent of the population. ``Farmers can begin to use [the trees] almost immediately,'' he says. They can plant them as living fences to mark property boundaries, frequently in dispute in this once-nomadic society.
Within one year the farmers can begin harvesting branches for firewood. Later they can grow the trees with maize and sorghum, fertilizing fields and protecting the soil from wind and rain erosion after crops are harvested.
Sandy, semiarid, and landlocked, Burkina Faso, about the size of Colorado, is home to some 8 million people, who traditionally farmed land until the soil was depleted and then moved on to let an area recover.
But modern population pressures have destroyed farmers' longstanding balance with nature. Nomads in search of new lands have moved into the Sahel region in the north, cutting trees, overgrazing sparse grasses, and abetting the spread of the Sahara.
In the central part of the country, farmers have cleared more and more forest to gain cropland and firewood. Today the landscape is stripped of trees within a 50-mile radius of Ouagadougou.
Ye expects strong support for his project from the Burkina Forest Service. ``The whole government is interested in reaching farmers,'' he says. ``We cannot plant enough to compensate for the cutting.''