There are more trees in Africa than we know….

When British colonial officials arrived in West Africa, they didn’t recognize the gardens they saw there. For them, gardens were tilled fields, crops in straight lines, and trees cleared. It suited the English climate – but not the West African climate, as James C. Scott explained in his remarkable book, Seeing LIke A State.

It was one of a series of examples Scott cites of people from one culture moving into another culture and imposing their views, without understanding differences of climate, plant growth, and sustainable agriculture. And these imported ideas of ‘scientific cultivation” remained with many African governments even after they became independent. In Niger, French colonial authorities taught farmers to remove sprouting trees from their fields each year before planting crops – the opposite of what they should have been counselling.

Only when West Africans went back to growing plants as they once did, and Niger’s farmers stopped clearing tree stumps, could agriculture recover and become sustainable once more.

I thought about that while reading a quite extraordinary story in Yale Environment 360, As Africa Loses Forest, Its Small Farmers Are Bringing Back Trees. It expands on an equally astonishing story about Niger that had appeared in National Geographic in April 2022, reporting on how farmers had been quietly reforesting their country but researchers had only discovered this much later.

In Niger, on-farm regeneration covered at least five million acres over 20 years, an average of 250,000 hectares per year, and probably represented 200 million trees. The farmers’ work, done by themselves, had far surpassed any work done by projects funded from outside. It brought more rainfall, and less dust storms. More young people stayed in villages because they could make a living. Food production became more complex, because there was fodder for livestock. The 200 million trees produced an estimated 200 million euros in natural products like fodder and medicine. Women said it only took half an hour to collect the same amount of wood that used to take 2.5 hours. Conflicts between herders and farmers dropped by 80%.

“Across the continent — from Senegal and Niger in the west, to Ethiopia in the east, and Malawi in the south — smallholder farmers are rejecting government advice that trees should be expunged from fields because they get in the way of growing crops,” says the Yale article. “Instead, they are allowing previously suppressed trees to regenerate on their land — to improve soils and crop yields; to provide harvests of fruit, fuelwood, and fodder for their livestock; and ultimately to achieve a better life for their families.”

It is a strategy that helps reverse desertification and addresses climate change, because the trees capture and hold CO2, which is warming our atmosphere.

Farmers in Ghana prune trees on land that they are preparing for growing crops. May Muthuri/World Agrofrestry, in Yale Environment 360.

An international team doing the first detailed analysis of automated satellite images reported in Nature Communications that at least 29% of tree cover in Africa is “outside areas previously classified as forest.” This matters because it means that what we know – or think we know – may be “a serious underestimate of the change going on across the plains of Africa”.

Other researchers – including some involved in discoving how Niger’s farmers had regreened so much of their country themselves – think the team’s algorithm fails to count the huge number of small trees outside forests.

“Chris Reij, a dryland restoration specialist at the World Resources Institute in Washington D.C., has seen firsthand how millions of farmers across Niger, southern Mali, and Ethiopia have begun nurturing natural regrowth of hundreds of millions of trees from long-suppressed roots beneath their fields” – often known as ‘farmer-managed natural regeneration’, says the Yale article.

“Meanwhile, Gray Tappan, a geographer at the U.S. Geological Survey, has mapped a dramatic increase in tree cover on farms in Malawi, Senegal, Niger and elsewhere,” the article adds. “And in a visual analysis carried out in May at the request of Yale Environment 360, he used sample satellite images to estimate that there are about 1.4 billion trees on farms across sub-Saharan Africa, more than three times as many as were spotted by Reiner’s automated system.”

In 2004, Reij drove 500 miles from Niamey, Niger’s capital, and was astounded to see trees everywhere. He teamed up with Tappan, who had access to remote sensing images, to estimate the scale of the farmer-led transformation, and continues to do so.

Reij now sees agroforest covering the 200 miles between Mali’s two largest cities, and says there is a ‘dense parkland of trees mostly less than 20 years old” on the border with Burkina Faso. Tappan says FMNR now covers more than 6.6 million acres of Senegal, showing that “woody vegetation can regenerate in a handful of years, even in regions of low rainfall.”

But both studies convey a hopeful narrative – that Africa has “many more trees than previously supposed” and that “many of these trees are newly established, regenerate naturally, and are being nurtured by millions of smallholder farmers,” the Yale article concludes.

Tony Rinaudo, working as Principal Advisor Natural Resources, Food Security and Climate Change for World Vision Australia, often travels to African Countries to discuss best practicies and learnings in natural regenreation of degraded areas. World Vision Australia

It takes us back, really, to James C. Scott’s story about how forcing West African farmers to adopt English farming techniques destroyed soil fertility. The colonial administrators in Niger who forced farmers to remove tree stumps did not understand African soil fertility either.

But serendipitous discoveries, by farmers who planted later than normal after returning from work overseas, and by Australian agronomist Tony Rinaudo who recognized that new trees were growing from the stumps, restored an earlier knowledge of sustainable agriculture because farmers are observers of their land and their plants and their climate. The FMNR practice itself received the World Future Council’s ‘Best Practice Agro-Ecology’ Award in 2019.

“Farmers in areas with high population densities need to intensify agriculture on increasingly small plots of land,” says Reij. “And to do that they need to improve soil fertility. Allowing trees to grow on their land can be the easiest and cheapest way of achieving that.”

Cheikh Mbow, now director-general of the Centre de Suivi Ecologique, a government agency in Senegal, notes that trees add to the amount of carbon stored on the land, helping fight climate change. He calculates that FMNR contributes up to 4 tons of carbon storage per acre per year, and told Yale Environment 360 that its widespread adoption by farmers in the Sahel is a major reason why that region has become a carbon sink since the 1980s.


As Africa Loses Forest, Its Small Farmers Are Bringing Back Trees. Yale Environment 360, Jun. 13, 2023

How farmers in Earth’s least developed country grew 200 million trees. National Geographic, Apr. 27, 2022

How Niger’s farmers regreened their land while hardly anyone noticed. Hopebuilding, Jun. 19, 2022

Cover image: Yale Environment 360 used this image by Tony Rinaudo of World Vision Australia (who discovered farmer managed natural regeneration and shared it widely). It is a photo of a farmer in Niger tending a tree sprout growing among his millet crop.