An OASIS is a fertile tract in a desert, usually with a spring or well that provides water for plants and animals. Oases are often surrounded by sand and can be found in deserts around the world. STEPPE is a type of dry grassland found in temperate regions of Eurasia and North America. It is characterized by low rainfall and a cold climate. LOAM is a type of soil composed of clay, sand, and silt. It is highly fertile and is often used in agriculture.