Because infrequent rains caused a desert environment to form in the first place.
Deserts receive much less rain than rain forests.
Grasslands
It get's less than 250mm of rain a year
Yes, that is the definition of a desert.
less than 25 cn
It is classified as a desert because it averages less than 10 inches of rain every year.
A desert receives less than 10 inches of rain per year. Some deserts, such as the Atacama (a rain shadoe desert), receive virtually no rainfall.
A desert receives less than 250 mm (10 inches) of rain per year.
less than 25 cn
The desert.
Desert soils
The biomes that receive little rain are deserts and tundras.