Preface to 'Adaptation of Plants to Water-Limited Mediterranean Environments'

Arid and semi-arid zones comprise approximately 40% of the world land surface.Plant productivity in these zones is limited by water.For instance, the annual production of dry matter ranges from 25 to 400 g/m 2 in the arid zones, and from 250 to 1000 g/m 2 in the semi-arid zones (Fischer and Turner 1978).These values are much less than those of up to 3000 g/m 2 for areas with abundant water (Fischer and Turner 1978).The Mediterranean environment is one of the four climatic regions of the arid and semi-arid zones.Mediterranean environments are characterised by cold, wet winters, and hot, dry summers.The main environmental constraints to the productivity of crops, pastures, and trees in these environments are high temperatures and water deficits during the summer and, on some soil types, transient waterlogging during early winter.The Mediterranean climatic region of Australia contributes about 60% of the cereals, 50% of the oilseeds, 90% of the lupins, and 60% of the pulses produced in Australia.With the potential change in climate through global warming, the impact of waterlogging, high temperatures, and water deficits on the productivity of crops, pastures, and trees are set to increase for the foreseeable future.Without new management practices together with breeding strategies, annual crop,