Desert similar. They occur in regions where large temperature differences occur between sea and land. Moist warm air rises over the land, deposits its water content and circulates back to sea. Further inland, areas receive very little precipitation. The Thar Desert near the India/Pakistan border is of this type. In some parts of the world, deserts are created by a rain shadow effect. Orographic lift occurs as air masses rise to pass over high ground. In the process they cool and lose much of their moisture by precipitation on the windward slope of the mountain range. When they descend on the
Thar Desert was conceived to halt spreading of the desert to fertile areas. There are few local tree species suitable for planting in the desert, which are slow growing. Therefore, exotic tree species were introduced for plantation. Many species of Eucalyptus, Acacia, Cassia and other genera from Israel, Australia, US, Russia, Zimbabwe, Chile, Peru and Sudan have been tried in Thar Desert. "Acacia tortilis" has proved to be the most promising species for desert afforestation and the jojoba is another promising species of economic value found suitable for planting in these areas. There are several protected areas in the Thar Desert. Stretches