query: What is the most common type of desert?
passage: Desert climate
The desert climate (in the Köppen climate classification BWh and BWk), is a climate in which there is an excess of evaporation over precipitation. The typically bald, rocky, or sandy surfaces in desert climates hold little moisture and evaporate the little rainfall they receive. Covering 14.2% of earth's land area, hot deserts may be the most common type of climate on earth.[1]
passage: Chihuahua (state)
In the far eastern part of the state the Chihuahuan Desert dominates due to low precipitation and extremely high temperatures; some areas of the eastern part of the state are so dry no vegetation is found like the Sand Dunes of Samalayuca. There are two distinctive climate zones found in the eastern part of the state: Hot Desert (BWh) and Cool Desert (BWk) which are differentiated by average annual temperature due to differences in elevation. There is a transition zone in the middle of the state between the two extremely different climates from the east and west; this zone is the Steppe characterized by a compromise between juxtaposed climate zones.The state has a great diversity due to the large number of microclimates found and dramatic varying terrain. The flora throughout the Sierra Madre Occidental mountain range varies with elevation. Pine ("Pinus") and oak ("Quercus") species are usually found at an elevation of 2,000 m (6,560 ft) above sea level. The most common species of flora found in the mountains are: "Pinus", "Quercus", "Abies", "Ficus", "Vachellia", Ipomoea, "Acacia", "Lysiloma", "Bursera", "Vitex", "Tabebuia", "Sideroxylon", "Cordia", "Fouquieria", "Pithecellobium". The state is home to one of the largest variation species of the genus "Pinus" in the world. The lower elevations have a steppe vegetation with a variety of grasses and small bushes. Several species of "Juniperus" dot the steppe and the transition zone.