Rooting systems of western and southern African Faidherbia albida (Del.) A. Chev. (syn. Acacia albida Del.) —a comparative analysis with biogeographic implications

Abstract

Faidherbia albida is a well-known and widespread agroforestry species of the Sudano-Sahelian zone of West Africa. Recent collection and testing efforts have included attempts to introduce seed origins from eastern and southern Africa into the Sahel. These have generally met with failure. Despite superior early growth, mortality is severe by the first or second year. Trials conducted at the ICRISAT Sahelian Center in Niger have demonstrated that this is probably due to differences in rooting patterns between southern and western Africa origins. A separation of the species into two ecotypes, i.e., upland (western Africa) and riparian (eastern, southern and southwestern Africa) is proposed. Based on this argument, the Sudan/Ethiopia region is identified as a possible center of origin for the species.