Agroforestry is Regreening the Sahel

The African Sahel is the arid belt of land that forms a buffer between the Sahara desert to the north and the more temperate savannahs to the south. From the coast of Mauritania and Senegal to the west, the Sahel stretches over 3,500 miles to Sudan and Eritrea’s Red Sea coast to the east. Over 500 miles wide, this vast area forms the biggest front line on earth in the relentless battle against desertification.

For decades there has been nothing but bad news. Population increase led to overgrazing and unsustainable harvests of fuelwood. Equally if not more harmful to the Sahel ecosystems were the imposition of western methods of agriculture and forestry, techniques that began under colonial administrations and have been perpetuated over the past 50 years by well-intentioned aid agencies. A fascinating article by Burkhard Bilger in the December 19th issue of The New Yorker, entitled “The Great Oasis (subscription required),” documents a new and hopeful trend in the Sahel that may reverse over a century of environmental decline.

Back in the 19th century and through the first half of the 20th century, French colonial administrators in the Sahel attempted to develop commercial agriculture according to Western techniques that worked well in temperate zones, where sunlight needed to be maximized, but were disastrous in the arid Sahel, where crops responded better if they were beneath a protective tree canopy that attenuated the sunlight. The areas designated as forest were considered state property and were protected, but because farmers were prohibited from allowing trees to grow on in their agricultural fields, they would poach the trees in the protected woodlands because it was their only source of firewood. The new independent governments, backed by NGOs, continued these policies. The practical result was there was no incentive for people to sustainably nurture the forest reserves because they had no legal right to the trees, and since it was a crime to grow trees on farmland, the farmers had no choice but to steal the trees in the forest. And because the trees were necessary to preserve topsoil and filter the sunlight to crops, absent these trees the topsoil blew away and the crops failed.

In “The Great Oasis,” Bilger recounts the experiences of an Australian missionary, Tony Rinaudo, who recognized the destructive impact that well-intentioned aid efforts were having on the Sahel when he was working in northern Niger in the mid 1980′s. Here is Rinaudo’s insight:

“What if things were backward? Every year, the villagers cleared the brush to make room for crops, and planted trees around them. And every year the plantings failed and the brush resprouted from its old rootstocks. What if they just let it grow? What if they cut back only a portion of the native trees, let the rest mature, and planted crops between them?”

For over 25 years this reviving of the traditional practice of farming beneath a canopy of valuable trees that protect the crops by filtering the sunlight, preserving the topsoil from wind, and absorbing runoff has slowly caught on. So much so that just in Niger, over 12 million acres (nearly 20,000 square miles) have been reclaimed.

The photo below shows a satellite image of the Seno Plains in Central Niger, about 400 miles east northeast of the capital Bamako. In this 600 square mile image, the reforested areas can be seen as small nodes of green surrounding the towns. If you zoom closer, using Google Maps, you can see stands of trees spreading literally everywhere on this plain. Twenty five years ago the entire area was denuded of vegetation. The darker area in the upper left of the image is the Dogon Plateau, which is separated from the plains by the cliffs of Bandiagara. Standing on those cliffs today, Bilger writes:

“I could see the thatched roofs of a village tucked among some mango trees below. Beyond them, to the south and west, airy groves of winter thorn and acacia stretched to the horizon. The wind whipped across the plains so steady and sharp that it made my eyes water. But there was no sand in it.”

Another fascinating insight to emerge from Bilger’s report is the hopeful reality that more people did not equate to more environmental stress. Merging traditional agroforestry with access to modern agricultural techniques, the land reclaimed in Niger – and also in Mali and Burkina Faso – supports a far larger population than could have survived there in the past. As Dennis Garrity of the World Agroforestry Centre told Bilger, “It’s counterintuitive, but it’s true; the more people, the more trees.”

Agroforestry has proven potential to reclaim arid regions everywhere. When editing EcoWorld, I reported on successful examples of agroforestry reversing deforestation in India’s Rishi Valley (India’s Rishi Valley Renewal,  1996), El Salvador (Reforesting Central America with TWP, 2000), and Costa Rica (Profitable Reforesting, 2005).  Back in the 1990′s I enthusiastically wrote about agroforestry as a financially sustainable way to restore deforested regions, with posts such as “What About Sustainable Nurseries?” and “Autarky After the Roar“. Indeed, the stated mission of EcoWorld for the 14 years that I was editor was “To double the timber mass of the planet within 50 years” (by 2045).

Not only is agroforestry a financially sustainable way to reverse deforestation – with all that implies: enthusiastic local adoption, profitability, ability to increase the land’s carrying capacity, improved and sustainable agricultural output – but reversing deforestation may help increase rainfall in arid regions. In the post “Hydraulic Redistribution” references are provided to theories that mingle the disciplines of forestry and climatology. By extending the canopy of trees that transpirate water vapor, cloud formation is stimulated. When these clouds condense into rain, low pressure is created in the inland areas above these forests which pulls in maritime winds, bringing more clouds. It would be interesting to explore and hopefully uncover additional research in this area.

Meanwhile, agroforestry is a proven way to improve the quality of life for people living in the Sahel, at the same time as it restores the water tables, moderates the climate, and slowly revitalizes the Sahel as the vast buffer against the encroaching Sahara.

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