Desert Biome

Deserts and xeric shrublands are characterized by small amount of moisture. They receive an annual average rainfall of ten inches (25 cms) or less, and have an arid or hyper arid climate, characterized by a strong moisture deficit, where annual potential loss of moisture from evapotranspiration well exceeds the moisture received as rainfall.

The desert biome of the earth covers about 35 per cent of the total land area of the world. Desert are very dry, receiving less than 25cm. In the desert of Atacama of northern Chile, only a negligible amount of rain has ever been recorded-a 30-year annual average of only 0.005cm, making it driest part of Earth.

The area of the desert biome is increasing as there is increasing desertification because of human over interaction. Deserts and xeric shrublands occur in all tropical, subtropical, and temperate climate regions. Desert soils tend to be sandy or rocky, and low in organic materials. Soil is generally saline or alkaline.

Adaptations in Desert Biome

• Plants and animals in deserts and xeric shrublands are adapted to low moisture conditions. Hyper-arid regions are mostly devoid of vegetation and animal life, and include rocky deserts and sand dunes. Vegetation in arid climate regions can include sparse grasslands, shrublands, and woodlands. Deserts are inhabited by the Xerophytes which include succulent plants, geophytes, sclerophyll, and annual plants.
• Animals, including insects, reptiles, arachnids, birds and mammals, are frequently nocturnal to avoid moisture loss. In the southern Arizona, the unique Saguaro cactus grows to many metres in height and can survive up to 200 years of age if left undisturbed. First blooms do not appear until it is 50 to 75 years old.

Cold Deserts

Cold desert occur where seasonal shifting of the subtropical high is of some influence less than six months of the year. Specifically interior locations are dry because of their distance from moisture sources or their location in rain shadow areas on the leeward side of mountain ranges such as Himalayas and Andes.  Winter snows occur in the cold deserts but are generally light. Summers are hot-with highs varying between 30° and 40°C.  Night time lows-even in the summer, can cool 10° to 20°C from  the daytime high.