| Abstract: | Revegetation by trees and shrubs is examined as the best long-term option for controlling dryland salinity. Since hydrogeological features in a catchment control and cause salinity, it is shown that management programs using trees should be developed on a hydrogeological basis through the use of hydrogeomorphic mapping. Catchment planning should ensure that trees suited to the area, and preferably of commercial value, are planted in the best hydrogeologically determined positions in sufficient numbers to reduce excess recharge generated following clearing. The programme should integrate other biological measures to increase water use, which includes improved crop and soil management and the introduction of salt-tolerant plants. Since trees will take several years to exert their full effect on recharge, engineering methods such as groundwater pumping, which lower water tables, and contour banks, which capture and redirect surface water, can best be used as short-term measures. Case studies from catchments in Western Australia are used to illustrate the application of control measures. |
