Deserts and xeric shrublands

Deserts and xeric shrublands also called xerófila are a biome characterized by, relating to, or requiring only a small amount of moisture, usually defined as less than 250 mm of annual precipitation. It is the largest terrestrial biome, covering 19% of the earth's land surface area. They may be further characterized as hyperxerófila (very dry) and hypoxerófila (less dry).

Character of the biome

Biodiversity: Deserts and xeric shrublands may have a very diverse and rich flora. Reptile fauna may also be very diverse with pronounced local endemism in some regions.

Minimum resources: Many species track seasonally variable and patchy resources and require large natural landscapes to persist. Available water sources and riparian habitats are critical for the persistence of many species.

Poor soils: Because biomass productivity is low, the litter layer is almost nonexistent and the organic content of surface soil layers is very low. Also, evaporation tends to concentrate salts at the soil surface.