A farmer in Niger tends to a tree sprout growing among his millet crop. TONY RINAUDO / WORLD VISION AUSTRALIA

I am nearing the point where I can offer an update on the trees we have planted in advance of 1,000+ coffee plants going into the ground in their shade. Thanks to Fred Pearce, reporting in Yale E360, I have some inspiration coming from across the Atlantic on the broader value of those trees:

Dooki (Combretum glutinosum) trees grow on a millet field in Niger. P. SAVADOGO / ICRAF

As Africa Loses Forest, Its Small Farmers Are Bringing Back Trees

The loss of forests across Africa has long been documented. But recent studies show that small farmers from Senegal to Ethiopia to Malawi are allowing trees to regenerate on their lands, resulting in improved crop yields, productive fruit harvests, and a boost for carbon storage.

For decades, there have been reports of the deforestation of Africa. And they are true — the continent’s forests are disappearing, lost mainly to expanding agriculture, logging, and charcoal-making. But the trees? Maybe not, according to new satellite data analyzed by artificial intelligence and a growing body of on-the-ground studies. This new research is finding ever more trees outside forests, many of them nurtured by farmers and sprouting on their previously treeless fields.

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. 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.

As large areas of farmland across Africa turn from brown to green, the results are also good for local economies, offering an easy and cheap way to intensify their farming and increase output, as well as benefiting biodiversity and the global climate. An acre of growing trees on farmland captures and stores up to 4 tons of carbon from the atmosphere each year, researchers say.

The latest published evidence of Africa’s resurgent farmland trees comes in the first ever detailed analysis of satellite images of the continent carried out at a scale that can identify individual large trees outside forests. Florian Reiner, a remote-sensing analyst at the University of Copenhagen, working with an international team of colleagues, reported in Nature Communications last month that at least 29 percent of tree cover in Africa is “outside areas previously classified as forest.”

These often previously unmapped trees are not in plantations; they are mostly natural trees scattered across savanna grasslands, croplands, and pastures. “Many African landscapes are drylands, where trees outside forests are the major form of woody vegetation,” says Reiner. In large dry countries such as Sudan, Niger, Libya, and Mali, they make up the majority of tree cover. Often, they are where most of the countries’ wildlife is found. Until now, they were simply invisible to remote-sensing science.

Reiner’s analysis is the latest output from a long-term international project headed by Martin Brandt, a geographer at the University of Copenhagen. It programs computers using AI to identify trees in satellite images by their shape, orientation, shadow, and other physical features. Its long-term aim is to create a global database of trees growing away from the continuous canopies of forests…

Read the whole article here.