A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the land surface of the Earth is arid or semi-arid. This includes much of the polar regions, where little precipitation occurs, and which are sometimes called polar deserts or "cold deserts". Deserts can be classified by the amount of precipitation that falls, by the temperature that prevails, by the causes of desertification or by their geographical location.
Sand and dunes of the Libyan Desert
Valle de la Luna ("Moon Valley") in the Atacama Desert of Chile, the world's driest non-polar desert
Atacama, the world's driest non-polar desert, part of the Arid Diagonal of South America
Flash flood in the Gobi
A landscape is the visible features of an area of land, its landforms, and how they integrate with natural or human-made features, often considered in terms of their aesthetic appeal. A landscape includes the physical elements of geophysically defined landforms such as mountains, hills, water bodies such as rivers, lakes, ponds and the sea, living elements of land cover including indigenous vegetation, human elements including different forms of land use, buildings, and structures, and transitory elements such as lighting and weather conditions. Combining both their physical origins and the cultural overlay of human presence, often created over millennia, landscapes reflect a living synthesis of people and place that is vital to local and national identity.
A prairie: Badlands National Park, South Dakota
Tropical rainforest, Fatu Hiva Island, Marquesas Islands, French Polynesia
Tundra in Siberia
Taiga (boreal forest), Alaska