The Center has prepared a study of the bioregions in the Kingdom on the basis of the prevailing climate and environmental conditions. It aimed at specifying the temperature range, annual rainfall, percentage of evaporation and transpiration, in order to arrive at a clear picture of the climate and aridity, and its relationship with plant formations in the Kingdom. Awareness of the bioregions derives its significance from the fact that it is a good source of environmental, climatic, terrestrial and biological information which is required by development plans to design the agricultural policy needed to develop renewable natural resources, particularly with regard to those factors which play an important role in the growth of plants, and identification of environmental factors which abet usage of modern methods to arrive at environmental equilibrium and sustainable environmental development.