Economic value of plant diversity in arid environments

Plant diversity in arid environments is low compared with most other biomes. Yet the number of species in a given area is not necessarily a good measure of either their functional or economic importance. In the Wadi Allaqi Biosphere Reserve in Egypt's Southeastern Desert, 127 species of vascular plants have been recorded, with an 'importance value' being attributed to each species for seven different use categories. Two main uses are in grazing (65%) and as medicinal plants (45%). Around 20% are edible and 18% are used as fuel.