A desert is an ecosystem where annual rainfall is 10 inches or less. Deserts are dry, inhospitable environments. They occupy over one fifth of the earth’s land.
Deserts form where mean annual rainfall is 10 inches or less. The desert ecosystem is one of the most inhospitable environments for any organism to inhabit. Nevertheless, it is amazing to observe varieties of life forms surviving in the harsh and unfavourable conditions of the desert. Many deserts form beautiful landscapes. When the word ‘desert’ is mentioned, majority of us would visualise deserts as vast, hot, barren lands; however it is actually the dryness and not the temperature that defines a desert ecosystem. Deserts cover about one fifth of the earth’s land.
The arid environment of a desert (Scource: S. Rossi)
The descending air masses occurring near 30 degrees latitude create the dry and hot climate of deserts. Dry air and scant coverage of clouds in in deserts are responsible for the low rainfall and hotness in deserts. Many of us think that there are only hot deserts in this world. Contrary to this common misconception, there are cold deserts as well. In addition, even hot deserts can get very cold at night and during winter. In some hot deserts during winter and at night, the temperatures can reach below zero degrees Celsius. Hot and cold deserts are the two main types of deserts found on earth.
Sahara Desert (Source: sntgmdm)
Cold deserts are found near or towards the two polar ice caps of the world. It snows quite a bit in this type of deserts. The temperature remains very low throughout the year. Cold deserts are characterised by long, cold winters where the average temperature is below freezing point. As these deserts are often covered in snow, you will find very little vegetation. Mosses, grasses and few scrubs are the few kinds of vegetation in cold deserts. In cold deserts, plants are scattered. They are deciduous and have spiny leaves.