ABSTRACT
Greening of the desert, which implies conversion of many arid regions into lands that support a standard of productivity equal to or surpassing that of today's more humid areas, represents one of the greatest challenges con fronting the family of man. Accelerated population-growth results in an ever increasing number of 'environment refugees', thus 'greening of the deserts' carries obvious political ramifications: The deprivation prevailing today in the dry lands could, if accentuated, threaten world peace. Desertification is undermining the food-producing capacity of dry regions of Africa, Asia, and Latin America. Forestry and agriculture have a vital role in preventing the spread of deserts and in recovering some of the marginal areas already abandoned. Desert areas are defmed as such on the basis of the moisture available, which is a reflection of the amount of precipitation and the potential of evapotranspiration. Aquifers containing fresh and brackish water have been found underneath many arid regions the world over.
