Deserts are described in part by the amount of rainfall received per year (>10 inches per year). Furthermore, it is the potential for water loss from the surface of plants and the ground which exceeds the rainfall, resulting in a net loss which is defines the biome. The 4 regions of the desert in USA, created by geography and climate are characterized by unique species of flora and fauna. Notably, North America has a range of desert ecosystems featuring both hot and cold deserts.

4 Regions of the Desert Biome

Within close proximity to large mountain range(s), deserts are shielded from rain and susceptible to high winds. Located between the Rocky Mountains on the east and the Sierra Nevadas on the west, lies a basin containing the deserts in The United States. Undoubtedly, mountain ranges play a major role in winds and precipitation as well as the geology of the Desert Biome. Rain shadow is the phenomenon of precipitation falling on the peaks rather than in the valley below. There are 4 regions of the desert Biome in North America; these are the Chihuahuan Desert, Sonoran Desert, Mojave Desert and Great Basin Desert,

Hot Desert Biome

Together, the Chihuahuan Desert, Sonoran Desert and Mojave Desert make up the hot deserts of North America. For instance, within the hot desert biome are ecosystems that are characteristic of other biomes which vary based on elevation and type of precipitation. Even so, hot deserts may be described as seasonally cold at high elevations.

Regions of the Desert Biome: Chihuahuan Desert

By acreage, the largest of the four deserts in The United States, the Chihuahuan Desert, it’s primarily located in Mexico and covers part of west Texas and New Mexico. Despite having hot summers, the winters are characterized by frost and cold nights. Elevation in the Chihuahuan Desert can range from 3000 to 5000 ft. with lower elevations being alongside and in the Rio Grande.

As revealed by tools and measurements, summertime is when the Chihuahuan Desert receives most of its precipitation as monsoons are common during those months.

National Parks Units of Chihuahuan  Desert
Regions of the Desert Biome in USA; Featuring Unique Species
Flora of the Chihuahuan Desert featuring Unique Species
Big Bend National Park

Big Bend National Park is located at the northern end of the Chihuahuan Desert. Since most of the Chihuahuan Desert is located in Mexico, Big Bend represents the largest protected portion of the Chihuahuan Desert in the United States.  #bigbendnationalpark

Geology of Chihuahuan Desert

Calcium

Calcium-rich soil which is derived from limestone indicates that the entire region was once beneath a prehistoric sea. A layer known as caliche is under the soil and often exposed due to winds throughout the region.

Fossils

Consequently, the national parks and other areas of the Chihuahuan Desert are rich in fossils. For instance, It is not uncommon to unearth shark’s teeth and other marine fossils during a hike on any one of the trails at Big Bend National Park. Furthermore, On your next visit, be sure to tour the Fossil Discovery Exhibit at Big Bend National Park, for an opportunity to view some of the greater than 80 dinosaur species that have been found at Big Bend.

Limestone

Owing to its rich limestone content, the soil in the Chihuahuan desert gave way to a network of caverns found at Carlsbad Caverns National Park. Rainwater seepage moving within layers of the Earth’s crust “lifted” and exposed hydrocarbons and fossil fuels (oils) rich in sulfur sulfuric acid. Next, the process of sulfuric acid dissolving limestone forming giant caverns, speleothems and large gypsum deposits. Carlsbad Caverns represent some of the most intricate speleothems worldwide with cathedral like rooms at depths of more than 1000 ft. below ground.

Lechuguilla Cave

Lechuguilla is the 10th longest cave in the world and the 4th longest in the United States. Lechuguilla Cave is adjacent to and most likely under Bureau of Land Management (BLM) land. BLM-managed areas allow for gas extraction and oil drilling. Consequently, fluids and/or gasses have the potential to leak into the cave’s passages and likely harming the fragile ecosystem. The gasses can wipe out unique species within the cave and endanger the lives of people researching and exploring within the cave.

Grand Exploration

Recorded as the second deepest limestone cave in the country, Lechuguilla is also the 3rd deepest cave in the United States. Also located in New Mexico, Lechuguilla has many unseen speleothem types due to its relatively recent grand exploration in July of 2019.

Gypsum

To top all of the aforementioned statistics, this cave system boasts the largest collection of gypsum stalactites in the world. Gypsum is the primary component of the white sand found in White Sands National Park and Preserve. While not white in color, the clear sand crystals reflect light and give off the white snow-like appearance. Lastly, gypsum does not absorb heat from the sun and is cool to the touch.

UNIQUE Species of the Hot Desert

Flora of the Chihuahuan Desert

Due to differences in temperature and elevation the flora of the Chihuahuan Desert is diverse from north to south and from valley to peak. In the north and low lying areas of the Chihuahuan Desert, tarbrush and lechuguillas are widespread. Specifically, grasses are particularly frost tolerant as well as yuccas and agaves which are found in the region. At even higher elevations, Pinyon pine and Alligator juniper are prevalent as they create a tree zone. As a result of the heavier rainfalls in the summer, the growth of summer annuals occurs in the summer.

Cacti

Two unique cacti to the Chihuahuan Desert are Bokes button cactus and living rock cactus which sustain life by attaching to dry limestone ridges.

Fauna of the Chihuahuan Desert

The iconic roadrunners makes their home within the Chihuahuan Desert and it is not uncommon to see roadrunners, but don’t blink, they are fast! Namely, pronghorn antelope (deer), desert pupfish, rattlesnakes, bobcats and red tail hawks are also local residents of the region. Generally, the reptiles, birds, and fish and mammals get their water from underground sources in the Chihuahuan Desert.

Regions of the Desert Biome: Sonoran Desert

Receiving the most precipitation, the subtropical Sonoran Desert is the wettest desert in the world and the hottest desert located in Northern America. Of note, the Sonoran Desert receives rain in a bimodal pattern (both summer and winter) with monsoons being common in the summer months. #monsoons

National Parks Units of the Sonoran Desert

Geology of Sonoran Desert

Basin of the Sonoran Desert

A basin shape traps moisture and air in the Sonoran Desert facilitated by the blockade of peaks from the mountains and ranges which completely surround this area.

  • Northwest, the Sierra Nevadas
  • Northeast, the Mogollon Rim of the mile-high Colorado Plateau
  • East, the Pinaleno and Chiricahua Mountains
  • South, the Sierra Madres in Mexico
  • West, the Sierra San Pedro Martir and coastal Laguna Mountains

The basin and range that we see shows that the basins are filled with sand, gravel and clay such as the area known today as Tucson. The seismic activity along the San Andreas fault could have accounted for the separation of the Baja California Peninsula approximately 6 million years ago. With a relatively low seismic activity in the Sonoran Desert, the last reported earthquake was at the end of the 19th century in 1887.

UNIQUE Species

Flora of the Sonoran Desert

High rainfall in the summer and the winter influence the growth of annuals in both summer and winter in the Sonoran Desert. For that reason, diverse and numerous, species of flora fluorish in this desert biome. To illustrate, the Sonoran Desert is known for the Saguaro cacti which have grown as tall as 65 ft high.

Buckhorn cholla, yucca, foothills palo verde, acacia, agave, prickly pair and summer poppy are other flora found in this biodiverse desert. #buckhorncholla

desert biome
Regions of the Desert Biome in USA
Fauna of the Sonoran Desert

Large mammals found in the Sonoran Desert are mountain lions, collared peccaries (javelinas), desert bighorn sheep and coyotes. Smaller animals such as woodpeckers, bats, horned lizard, Gila monster, jackrabbit, the white winged dove make the Sonoran Desert their home. Finally, known for their ability to elicit fear and alarm, tarantulas, scorpions, and the most venomous rattlesnake, the Sonoran rattlesnake have become legendary fauna of the region.

Regions of the Desert Biome: Mojave Desert 

The Mojave Desert is the westernmost desert in North America.   When giving details on a specific biome or ecosystem, I look for superlatives as a way to emphasize the WOW factor. Mojave desert is not short on superlatives.  

Receiving less than 2 inches of precipitation a year, the Mojave Desert is the driest desert of North America. In addition, the Mojave Desert has also the hottest air temperature and surface temperature recorded on earth and the lowest elevation in North America. Despite some recent claims that surface temperatures in other regions have been recorded higher but due to the absence of appropriate devices, the Mojave desert retains the distinction as the hottest single location. By contrast, temperatures in the Mojave Desert are colder in the winter when compared to winter temperatures in the Sonoran Desert.  

National Parks Units of Mojave Desert
  • Castle Mountains National Monument
  • Death Valley National Park
  • Grand Canyon-Parashant National Monument
  • Joshua Tree National Park
  • Lake Mead National Recreation Area
  • Mojave National Preserve
  • Tule Springs Fossil Beds National Monument
  • Zion Park National Park
Death Valley National Park

Death Valley National covers 5,270 square miles (3.4 million acres), making it the largest national park in the “lower 48”. New heights to the mercury occured less than 10 years ago in Death Valley with temperatures measured at 130°F (54.4°C) on July 10th, 2013.

The Mojave Desert, alive and out of this World!
Joshua Tree National Park

Whimsy and imagination run amuck here in the National Park which bears the name of its namesake succulent.  Hiking trails and boulder climbing are among the recreational activities within the park.  

UNIQUE Species of the Hot Desert

Flora of the Mojave Desert

Mormon tea, Buckhorn cholla, Mojave yucca, and the Joshua tree are representatives of the unique flora found in the Mojave Desert.

Fauna of the Mojave Desert

Mojave rattlesnake, mountain lion, desert tortoise, Mojave tui chub, and the tarantula hawk (a wasp that devours tarantulas after paralyzing them) are some of the fauna found in the Mojave Desert.

Cold Desert Biome

Regions of the Desert Biome: Great Basin Desert

Compared to the other three deserts discussed above, Great Basin Desert is unique as it is classified as a cold desert since most of the precipitation in the Great Basin Desert Falls as snow. In fact, The Great Basin Desert is one of the largest cold deserts in the world and was formed during prehistoric times. 

National Parks Units of Great Basin desert
  • Golden Spike NHP
  • Great Basin National Park
  • Hagerman Fossil Bed NM
  • Manzanar National Historic Site
  • Timpanagos Cave NM
Great Basin National Park

Located in the Great Basin Desert.  Great Basin National Park is one of the least visited national parks with fewer than 100,000 visitors per year. Two fantastic opportunities for visitors within Great Basin National Park are climbing Mt. Wheeler and visiting Lehman Caves.

Ward Charcoal Kilns

Just outside the Great Basin National Park boundary are a set of perfectly preserved charcoal kilns. Watching the sun rise from against the golden brick of these kilns is an incredible experience. #charcoalkilns

Geology of Great Basin Desert

A unique characteristic of The Great Basin is that it is endorheic.  As a result, snow melt in the form of rivers does not go into the ocean or seas. All water from rivers run into marshes and wetlands and sinks into the soil or evaporate.

Endorheic

The endorheic system may account for the massive cave system beneath the ground, known as Lehman Caves.

UNIQUE Species of the Cold Desert

Flora of the Great Basin

Upon first glance, the Bristlecone pine is unassuming; yet is is one of the oldest living species in the world. Yellow and orange splendor of the apen awaits you during the second or third week of September as the aspen forest change color.

Fauna of the Great Basin

Kangaroo rat, desert cottontail, mountain lion, mule deer, elk and bighorn sheep are common species found in the Big Basin Desert.

What is endorheic?

The word endorheic is a term used to describe a type of basin or watershed that does not flow into one of the oceans. Great Basin in Nevada is one such system where rivers or water seepage does not flow beyond the basin. Water may collect at specific times of the year in a lake and solutes may accumulate due to evaporation whereby increasing the salinity of the endorhic lake. Once example of an endorheic lake is Great Salt Lake in Utah.