Both Ailanthus altissima and Prosopis chilensis are important species being used in afforestation in different parts of Pakistan. These species are hardy enough to minimum moisture and therefore, are very suitable for the hot deserts of this country. Ailanthus altissima is native while Prosopis chilensis has been recently introduced by PFI from Chile. The species was found better than native Prosopis i.e. Prosopis juliflora and Prosopis cineraria.