Ask Dr. Green: Planting Trees in Africa

Last week, I received a question from Byaruhanga Denis, a college student at the Makerere University, a prestigious research institution in Kampala, Uganda. He wanted to know "why is it that people in developing countries are reluctant to plant trees
despite the bulk indigenous knowledge on trees/shrubs?" This topic was well beyond my scope of knowledge, but I've done some research and I think I've found an answer to this rather fascinating question.

There are countless advantages to planting trees anywhere, but in Africa, especially, the benefits are quite persuasive. In addition to the absorption of carbon dioxide in the air, trees are invaluable tools in water and soil conservation in the driest areas of Africa; they also help prevent wind erosion. They provide valuable non-wood forest products (NWFPs) like gums, saps, resins, honey, and medicinal plants, which play an important role in local economies. In an area where desertification due to climate change is already beginning to become a reality, the importance of planting trees must not be underestimated.

Unfortunately, as Byaruhanga points out, there is a reluctance among local farmers and governments alike to plant new trees, especially indigenous species. Since many farmers live well below the poverty line, the cultivation of cash crops like cowpeas and groundnuts is much more inviting than planting trees; the issue of farmland tenure compounds the problem--farmers are less likely to plant slow-maturing trees, which are viewed as a long-term investment, when they are unsure whether they will still own the land once the trees have matured. The physical selling of tree seeds and seedlings has proved problematic: large-scale nurseries are impractical, as they require a lot of water, and thus seeds, and especially saplings, have become harder and harder to come by. The misconception that trees will not grow in dry regions without large amounts of water is very widely held in Africa; research has shown that certain species can thrive on very little water, although those species are not very numerous and not very easy to come by. According to Farms, Trees and Farmers: Responses to Agricultural Intensification, by J. E. M. Arnold and Peter A. Dewees, there is an innate reluctance associated with planting trees in many African cultures--some cultures believe that only God can plant indigenous species, while others believe that trees are "'something already there, to be used or managed' rather than to be planted." (Interestingly, many of these cultural restrictions only apply to indigenous species--farmers are free to plant exotic trees.)

Despite all of the many problems faced by African nations today, there are efforts underway to plant trees, especially indigenous species, in African soil. Spearheaded by the U.N. Food And Agricultural organization, the Parklands system works with farmers to plant trees in unused portions of crop fields across Africa, especially in the dry regions. Some African nations, including South Africa, are instituting tree planting programs à la Los Angeles, complete with incentives and distribution programs.

For more information on this topic, check out this report from the European Tropical Forest Research Network.