The Sahel region is the front line in the struggle between an ever threatening Sahara Desert and efforts to maintain and extend the fertility of West African soil. But local farmers have a secret weapon – the gao tree. By letting these indigenous trees, which are perfectly adapted to the region’s conditions, flourish among their crops, the farmers have been able to regenerate once arid fields

The Sahel is a savannah region stretching from Senegal in the west, right across Africa to Ethiopia and Eritrea in the east, forming the boundary between the vast sands of the Sahara Desert to the north and the fertile farming regions to the south. When the droughts of the 1970s and ‘80s struck, causing widespread famine, local people and aid agencies looked to ways that they could protect the harvests and hold back the march of the desert.

A feature of the landscape of Niger, in the central Sahel and one of the world’s poorest countries, was always its immense baobab and gao trees rising above the grass and thorn scrub. Although these trees are highly adapted to the region’s harsh conditions, they suffered not only the effects of the droughts but of the pressure of the population on the land. The trees, whose leaves can be eaten, their pods used for cattle fodder, and their wood for fuel, began to disappear, and along with them went all the added benefits they brought, such as fertilising the soil, holding back erosion, shading crops and so on.

Studies in Niger bore out local folk wisdom that the gao trees (faidherbia/acacia albida) in particular were the farmers’ best friend. The gao, a member of the acacia family that grows up to 30 metres tall, has the unique characteristic of losing its leaves in the rainy season, thus providing welcome dappled shade for crops in the growing period but not competing with them for water, nutrients or sunlight. The tree releafs in the long dry season, increasing its shade cover and protecting the soil. But according to Nigerien law, gao was a protected species, and therefore the trees were owned by the government. This lead to confusion and conflict over who could benefit from the trees and, therefore, who was responsible for their well-being.

In the 1980s, the Nigerien government working with the United Nations conducted studies on how to regenerate the gao population without expensive reforestation projects. Their proposal was to encourage farmers to allow the tree’s seedlings to grow wherever they appeared, instead of removing them from their fields. And where the trees struggled to re-establsih themselves, they developed seedling production techniques that were low cost in time and energy. Non-governmental organisations supported the approach.

“We were trained to help encourage this kind of natural resource management – trees are to be cultivated, not cleared,” says ‘Souley’ Scott, a blogger who volunteered with the US Peace Corps in Niger in the 1990s.

A key to the success of the program was a change in the local laws where the protected status of the trees, which meant they were in theory owned by the Government, was changed to allow for private ownership and, thereby, gave farmers greater incentive to nurture and protect the trees.

Since then, the trees have flourished – and so have the crops grown under them. Gao trees fix nitrogen in the soil, while their leaves, which conveniently fall in the rainy season when everything else is trying to grow, add to the organic fertility of the soil. And the trees help hold the soil against erosion. Their leaves and seed pods provide food, and their branches wood for fuel, fence posts and implements, which the farmers can either use themselves or sell.

The re-establishment of the gao and other trees has led to a regeneration of Sahel region of Niger. According to the New York Times, February 11, 2007, conservation and improved rainfall has led to at least 7.4 million acres being newly covered in trees. The article quotes Chris P Reij, a soil conservationist who has worked in the Sahel for over 30 years, saying, “The density [of the trees] is so spectacular…. The general picture of the Sahel is much less bleak than we tend to assume.”

Souley Scott says in his blog, “Mature, old baobab and gao trees are extremely beautiful. They’re the kind of tree that gets etched into your mind; when you picture Niger you see these trees silhouetted against the sandy, orange sunset-lit sky.”

And beneath them is a growing harvest.