The decline of the Vulnerable yeheb Cordeauxia edulis, an economically important dryland shrub of Ethiopia

Abstract

AbstractCordeauxia edulis (Leguminosae: Caesalpinioideae), commonly called yeheb, is a small tree/shrub species endemic to Ethiopia and Somalia. The tree produces nuts that are consumed as a staple food by pastoralists and are sold in local markets. Recent reports indicate that C. edulis has vanished from many locations where it was noted by earlier travellers and, as a result, it is currently categorized as Vulnerable on the IUCN Red List. To assess the current status of the species we studied it around 10 villages in Boh district in the Somali Regional State of Ethiopia, where the only known remnant stands of C. edulis in Ethiopia are found. The results show that these populations of C. edulis are declining and natural regeneration is negligible. We recommend that yeheb should be categorized as Endangered on the IUCN Red List, based on criteria A1d, because we estimate that there has been at least a 70% reduction in population size from overexploitation. The major constraints to natural regeneration and imbalance in the population structure are over-harvesting of immature nuts, excessive browsing of shoots and leaves by livestock and excessive cutting of wood for fuel and construction. We recommend that conservation measures for the species focus on sustainable harvesting of mature nuts, raising awareness among local people, preservation and monitoring of remnant populations and introduction of the species in ecologically suitable sites.