Effects of salinity on native shrubs and one near extinct tree species of Kuwait: potentials for restoring degraded desert ecosystem

In view of the rapidly declining native plant cover due to existing harsh climate and uncontrolled grazing, Kuwait has undertaken initiatives to revegetate the desert land with native species to improve plant cover, soil stabilization, biodiversity and ecological processes. Because of the high temperature during long summer months and sandy soil types, transplanted seedlings are irrigated regularly, mostly with brackish groundwater. This study was undertaken to evaluate survival, growth and proline accumulation of transplanted Vachellia pachyceras, Rhanterium epapposum, Farsetia aegyptia and Haloxylon salicornicum seedlings that were irrigated with four levels of saline water ranging from EC 1.6 to 5.5 dS/m for 14 months. Irrigation with different salinity levels had no significant effect on seedlings survival in V. pachyceras, H. salicornicum and R. epapposum while F. aegyptia exhibited only 38% survival under brackish water irrigation. Total plant biomass declined with increasing salinity in irrigation water except in R. epapposum. However, salinity of irrigation water did not increase proline content. Present results suggest that revegetation involving these four native species can be implemented using brackish groundwater with salinity level up to EC of 5.5 dS/m in arid and semiarid regions where freshwater is scarce and need for revegetation is critically important.