Baobab and Marula

Both baobab (Adansonia digitata) and marula (Sclerocarya birrea) have a wide distribution in sub-Saharan savanna climates as well as unique ecological, economic, societal and cultural qualities, which underpin their agro-ecological potential. Marula has three subspecies, of which subsp. affra is found in southern Africa, subsp. birrea in western Africa, and subsp. multifoliolata in Tanzania.

These trees are typically two of the largest trees in the savanna environment, growing dispersed in the landscape, near farmlands or abandoned farmlands in particular, where they have been protected from grazing. Both species are listed among the priority tree crops for domestication in Africa. They provide local people with important nutritional and economic benefits (e.g., nuts, oil, juice, cosmetics), shelter and have a strong cultural significance in many African cultures. The marula fruit is rich in vitamin C (surpassing orange, mango, and lemon), oleic acid and antioxidants. The nuts contain high levels of minerals, protein, and energy. The stones of the nuts have immense potential as an ecological source of energy. Baobab is exceptionally resistant to fires, storms and damage caused by insects and mammals. Fruit has a high energy value, especially what comes to that can be further processed to food oil. Both are recognised as superfoods by urban and western markets. The fruit pulp is also an excellent source of dietary calcium for people inhabiting the dryer regions of Africa where dairy farming is a challenge. However, these potentials are hampered by outdated storaging and processing methods, scant marketing efforts, disorganized value chains, a lack of knowledge about nutrition and health advantage and climate resilience benefits, as well as “poor man’s food” perception.

The ecological roles of baobab and marula trees in agroforestry systems have not been well  documented, but because of their size and canopy structure, as well as their deep root system, benefits are expected through improved soil quality (e.g., organic-matter contents and nutrient availability, humidity regulation, and the maintenance of a favorable microclimate, which in turn can improve crop and fodder production. In addition, they are expected to promote biodiversity, e.g., of natural enemies for crop pests. These large trees also have a potentially significant role as a carbon storage – an important aspect related to the global carbon cycle, as savanna ecosystems cover large areas of the African continent (between 30-65 % depending on the definition of savanna vegetation), and 20 % globally. However, quantified data on the different ecological roles of these trees are scarce.

Sources

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