Biodiversity of ligneous species in semi-arid to arid zones of southwestern Niger according to anthropogenic and natural factors

A total of 23 species had completely disappeared from the study sites, i.e. five from the semi-arid and 18 from the arid zone. Thirteen different causes of tree species loss were recorded, six of them being of anthropic and seven of natural origin. Four disappeared species were consumed as leaves, buds, flowers and fruits while others were used as firewood and timber. All disappeared species were part of the traditional pharmacopeia. The plantation of useful species is suggested to improve re-introduction.