Semi-arid zone

Regions of moderately low rainfall, which are not highly productive, usually classified as rangelands. "Moderately low" is widely accepted as between 100 and 250 mm of precipitation per year. (Source: IPCC, 2007)

Regions that have between 10 to 20 inches of rainfall and are capable of sustaining some grasses and shrubs but not woodland. (Source: GEMET/TOE / DOE)