Baobab (Adansonia digitata L.) fruit production in communal and conservation land-use types in Southern Africa

Baobab fruit are harvested and used throughout Africa as an important source of food and are sold to generate income. Commercial use is increasing rapidly as derivatives of the fruit such as baobab seed oil and fruit pulp are being exported to Europe and North America. The cash derived from the sale of fruit support thousands of rural people. This study examines baobab fruit yields in an area being harvested for commercial use. It represents baobab populations and harvesting scenarios typically found in Southern Africa and is the first study in Africa to combine demographic and production data in determining baobab fruit yields. Fruit production was examined across five land-use types (nature reserves, rocky outcrops, plains, fields and villages) and over three consecutive years. Factors assessed included differences in life-stage, tree size, land-use type, inter-annual variation and quantifiable fruit predation. Results showed that adult trees produced 8 times more fruit than sub-adult trees. Fruit production fluctuated between size-classes and exhibited weak linear and logarithmic trends between fruit production and dbh and crown volume, respectively. There was high variation between trees with 41% of adult trees consistently producing <5 fruit per year, which we classed as 'poor-producers'. Different land uses showed no significant differences in fruit production per tree, but where baboons were present, in nature reserves and rocky outcrops, predation of immature fruit resulted in up to 85% fruit loss. Villages and fields had the highest tree density and yielded the most fruit/ha. Inter-annual variation was significant with a two and a half fold difference between the highest and lowest year. The results of this study are important for economic planning and management and are key to determining sustainable harvesting levels of baobab fruit in Southern Africa. (C) 2010 Elsevier B.V. All rights reserved.