Desert Biomes

Desert biomes involve more than sand dunes with an occasional oasis. Deserts provide for wonderfully adapted plant and animal life. Humans have also adapted to life in arid, desert areas. We live in such an area.

We've lived Southeast of the city of Tucson Arizona, nearby the Sonoran Desert. Our home then was in the Sonoran Desert for many years.

Then we moved to another area of Arizona, to a different desert biome - to the Chihuahuan Desert. Much of the plant life is similar. Many of the unique Sonoran features are not native to the higher elevations of the Chihuahuan Desert.

desert biomesA Desert Biome of Southern Arizona

We've experienced the wide variations of weather in these Arizona desert biomes. During summer, we've thought about how difficult it must have been in the early settlement of the West for people to live here. How did Native Americans, the original peoples, manage in the stark environment of a desert biome. I purchased a very good book, that helped me to understand the difficulties faced by settlers to Arizona in the 1800s.

It's about a woman who moved to Arizona from New England - imagine that! What a change. She tells of her experience, as a military wife in the late 1800s. It's an excellent true-to-life book by Martha Summerhayes. I highly recommend it! See more here:
Vanished Arizona: Recollections of the Army Life of a New England Woman

Desert Ecology

The essential elements that mark a desert biome are:

  1. Limited precipitation (maximum of 19 inches per year - often much lower)
  2. Very low humidity
  3. Receive a lot of strong sunshine

Other noteworthy points are related to their flora and fauna. Plants are very specialized to the desert biome in which they grow. Animals also are adapted to desert life in various ways.

Arizona Monsoon StormMonsoon Storm Enlivens the hot/dry Arizona desert biome

There are essentially 4 types of deserts throughout the world:

  • Hot/dry - Winters are normally warm; summers are fairly long and hot. Temperatures in the summer can range up into 100F+ degrees. Winter will generally be around 60 to 70F range. In all seasons, with clear skies, the temperature at night will normally drop up to 30F+ degrees. This happens because of the very low humidity. Moisture acts to retain heat. Rainfall happens mostly in the summer - with thunderstorms [read more>] bringing a sudden deluge that can cause flash floods. There also can be winter storms with a more gentle and/or sporadic rain, occurring lightly over a day or two. Many deserts can get an average of 12 inches of rain per year, but it can be as low as just an inch in some areas.
  • Semiarid - Summers are long, but temperatures not so extreme as hot/dry - about an average of 80F degrees. Occasionally as high as 100F. Nights do cool down, with low humidity - to about 50F degrees. Rainfall is sporadic. It generally varies up to as much as 2 inches in a year, mostly with winter storms.
  • Coastal - Summers here are somewhat long, but also cool. Temperatures average about 74F degrees, but sometimes climb to 95F. In winter, temperatures hover just above freezing, sometimes dipping below. Rainfall averages per year varies according to the area, ranging from nearly none to as much as 14-1/2 inches.
  • Cold - Summers are short and provide some warmth. Temperatures average in the 70s Fahrenheit. Winters are long and cold, with temperatures remaining right around the freezing mark. Precipitation comes almost totally in the form of snow - averaging up to 10-1/2 inches per year, along with a spring rainy season. Some areas also have a small amount of rain in the fall.

Habitats of Desert Biomes

Canyons

Canyons are found in many desert biome areas. The Grand Canyon is one of the more famous ones in the world. Canyon comes from a Spanish word that means pipe or tube.

Sometimes people refer to a canyon as a gorge - yet a gorge is a much smaller type of feature than a canyon. A gorge is narrower, and its walls are typically more steep. However, we won't quibble over the two! A canyon's features are quite similar - just much grander!

A canyon is a type of valley, but it has steep cliff-like walls. The valley within a canyon is also relatively narrow. It's a deep valley, relative to the walls surrounding it.

A canyon is most often formed by a river. The Grand Canyon is a prime example, formed by the Colorado River. Over time the water wears away at the river-bed, creating erosion. Some tectonic action - movement of the earth's plates at geologic rifts and faults - helped in its formation also.

Grand Canyon Nation MonumentAwesome view of the Grand Canyon at the National Monument at Parashant

Sediments on river floors help in wearing the down the river-bed further, as they move along. The bed is carved deeper and deeper into the earth, until a canyon is formed. Flash flooding exacerbates this process, speeding it up. This geological process does take millions of years!

Weather also aids canyon formation in desert biomes. When viewing rocks on mountainsides, think of rainwater or snow falling there. As this moisture gets into cracks in the surfaces, over time it works on these openings - eroding them.

Other actions involve temperature variations. The freezing and thawing. The movement of rain water and sand wearing on the surfaces. Over millions of years, the surface erodes away forming a dry canyon or a slot canyon. A river is not needed in these cases.

The other method for canyon formation occurs in areas of earthquake activity. This happens with tectonic formation. When movement of a tectonic plate makes a fault line dip between one plate to the other, a canyon can be formed. These can be seen along the famous San Andreas Fault in California.

Canyons are quite scenic, and take various shapes. Box canyons, slot canyons, etc. Some people specialize in climbing canyon walls, others in hiking through canyons.

Desert Biomes & Ecosystems

It's amazing to think of it - but actually one-fifth of the earth [See a Comparison>] is made up of desert biomes!

Most desert biomes of the earth are located in specific areas. In the Northern hemisphere, between 15 and 35 degrees latitude. Similarly in the Southern hemisphere, between 15 and 35 degrees latitude. This places them central to the Tropic of Cancer in the North, and central to the Tropic of Capricorn in the South. The cold deserts, however are in the Arctic areas. Arizona contains 3 desert biomes.

North America

  • Sonoran Desert
  • Chihuahuan Desert
  • Great Basin
  • Mojave Desert

South America

  • Atacama Desert
  • La Guajira Desert
  • Patagonian Desert

Australia

  • Simpson Desert
  • Great Sandy Desert
  • Great Victoria Desert

Africa

  • Sahara Desert
  • Chalbi Desert
  • Kalahari Desert

Asia

  • Gobi Desert
  • Thar Desert
  • Kara Kum

Europe

  • Ryn Desert
  • Melnik Desert Canyon
  • Bardenas Reales
  • Accona Desert

Arctic

  • Greenland Tundra
  • Antarctica Desert

Islandia

  • Rangipo Desert