Most recent stories ›
AgroInsight RSS feed

The desert recedes July 24th, 2016 by

In the 1980s desertification was a cause for alarm. The basic idea was that smallholders in the Sahel were grazing too many animals and cutting down too many trees. As a result, the Sahara was creeping into the Sahel, turning fields and pastures into desert. The reality turned out to be more complex than that.

By the 1990s, academics had debunked the idea that peasants caused desertification. In Gourma, Mali for example, there was no relationship between deforestation and domestic firewood consumption, because smallholders gathered deadwood as fuel, and did not down cut live trees (Benjaminsen 1993). In fact, the boundary line between the desert and the Sahel had not changed in the 16 years between 1986 and 1998. Rather, the boundary ebbed and flowed with changes in annual rainfall (Nicholson et al. 1998). The number of individual trees in West Africa did decline in the second half of the twentieth century, but this was largely because of the droughts of the 1970s and 1980s.

Remarkably, smallholder farmers in the Sahel were actually encouraging the natural regeneration of trees. In a hiking survey of 135 villages in Senegal, Patrick Gonzalez noted that when a tree sprouted, people would protect it, and when it was large enough prune it (Gonzalez 2001). This may strike some readers as wishful thinking, but William Critchley and colleagues at the University of Amsterdam have also documented farmers in the Sahel protecting small trees. Critchley et al. have made several videos on how farmers in the Sahel use various simple techniques to encourage trees. Farmers dig small pits that collect rain runoff. By applying manure in these pits the soil is improved and when a tree seedling germinates, farmers keep livestock from nibbling it away.

1975 copiaAs an added bonus, many of the trees that seemed to have died in the 1970s and 1980s still had life left in the roots. As the branches began to grow back from these “underground forests” farmers protected them as well.

In his video Managed regeneration, Critchley uses aerial photos of the village of Galma, Niger to show that dramatic recovery of vegetation between 1975 and 2002.

2002 copia It is worth noticing that the Sahel is recovering from the droughts of the twentieth century, and that smallholders do value trees, and take some steps to encourage reforestation.

neem treeDuring the drought decades, international projects funded nurseries of eucalyptus and other exotic trees in the Sahel, but most of these died (Gonzalez 2001). One might be forgiven for assuming that foreign trees are simply inferior to native species, but it’s not quite that simple. Eric Boa points out that in the Sahel the single most important tree across the transition zone from arid to semi-arid is not actually a native species, but the leafy neem, a native of South Asia which was introduced to Africa about 100 years ago.

Neem now grows from Mali to Sudan. Neem trees are fairly drought-tolerant, but even they declined in the early 1990s, probably because of the long dry spell. Some activists prefer indigenous species, such as Balanites aegyptiaca, but neem grows much faster, which is why people like it (E. Boa, email). In the past few years I have been impressed by the sight of great neem trees around farmsteads in Mali.

Rural people know as well as anyone that trees provide fuel, timber, shade for livestock, fruit and other services. No doubt future generations in the Sahel will encourage native trees, and continue to plant naturalized foreigners like neem, adapting to the slow rhythms of moister and dryer decades.


Further viewing

You can watch the videos here. Managed regeneration, and Parkland agroforestry.

Further reading

Benjaminsen, Tor A. 1993 Fuelwood and Desertification: Sahel Orthodoxies’ Discussed on the Basis of Field Data from the Gourma Region in Mali. Geoforum 24(4): 397-409.

Gonzalez, Patrick 2001 Desertification and a Shift of Forest Species in the West African Sahel. Climate Research 17:217–228.

Design by Olean webdesign