FYA: For Your Awareness
Desert biomes cover about 20% of the earth’s surface from the Sahara (hot desert located in North Africa) to the Gobi (cold uplands located in Northern China and Mongolia) and are some of the harshest environments on the planet.
What is a Desert?
Deserts are extremely dry environments that receive less than 10 inches of rain per year. The rate of evaporation often exceeds the total amount of precipitation resulting in harsh conditions for animals and plants. Over time, specialized vegetation and wildlife have adapted to the extreme weather conditions of hot temperatures during the day, followed by dramatic temperature drops at night along with the inconsistent rainfall.
Surprisingly deserts aren’t just large expanses of sand, they can be rocky plains or mountainous regions or a combination of sand and varying geology. Many deserts are rocky barren expanses because the fine sand has blown away leaving the rocky surface below. One of the most well-known deserts is the Sahara, but there are also deserts in the Arabian Peninsula, India, Australia, Southwest Asia, and Western Africa. Smaller deserts are also located in North and South America and deserts also exist in very cold environments such as the Arctic and Antarctica.
While deserts appear to be hostile environments, they are home to animals and plants that have adapted to these harsh conditions. Plants can be dormant until they receive rainfall and then grasses and flowers spring up quickly and disappear again. Cacti and other desert plants absorb and store water having thick waterproof skins, small or no leaves and are often covered with thorns to protect against water loss and foraging animals. Trees such as Acacias have long roots that access moisture deep in the ground; they lose their leaves during extreme droughts.
Deserts of the world are determined based on where they are located, what type of climate they require and are defined by their aridity (lack of moisture). Deserts contain several different habitats and are classified into four types: Hot and Dry, Semiarid, Coastal and Cold.
1. Hot and Dry Desert
When asked to describe a desert, most people think of a hot and dry desert. Daytime summer temperatures can be extreme reaching up to 120 degrees, while nighttime temperatures can vary as much as 60 degrees. Due to a lack of humidity they receive twice as much of the amount of solar radiation as the moist regions of the world. They receive very little rainfall but the water evaporates quickly often exceeding the rainfall amount. Plants and shrubs have evolved to retain water and include cacti, small shrubs or trees and animals include reptiles, birds, and burrowing nocturnal animals. Date palms and camels are examples of species that have adapted to these extreme desert environment. Hot and dry deserts are found in the African Sahara and the North American Sonoran desert.
2. Semiarid Deserts
Semiarid Deserts experience long Summers with temperatures up to 80 degrees and cool nights. They receive small amounts of rainfall mostly in the summer season. Cool night temperatures keep moisture from evaporating as quickly as hot deserts. The soils are often sandy and/or loose gravel with very little salt. Think of plains covered with sage brush. The plants that have adapted to semi arid deserts are covered in spines preventing evaporation and creating shade. There often have shiny or glossy leaves which allows for the reflection of light, slowing down evaporation. Plants include creosote bush, bur sage white thorn, cat claw, mesquite, brittle bushes and jujube. Insects and animals follow the shade of plants. Jack rabbits, skunks, reptiles , and burrowing owls are found in semi arid deserts. These deserts are located in Utah and Montana and also in the higher latitudes of Europe, Newfoundland, Greenland, Russia, and Northern Asia.
3. Coastal Deserts
Coastal Deserts are often found on the western edges of a continent and are created by cold water currents along the coast. They can be foggy in winter and in summer the temperatures can reach 75 degrees. Coastal deserts are found at the intersection of terrestrial, oceanic, and atmospheric systems. Plants often have thick foliage and good water retention. Animals have adapted to the heat and lack of water with accelerated life cycles, activated by rainy season and reaching maturity quickly, while some insects eggs remain dormant until the environment is conducive to being hatched. Animals include coyotes, eagles, owls, amphibians, and insects. Coastal deserts are found in North America and Mexico, Central America, Greenland and the Caribbean. The Atacama Desert in Chile is considered to be the driest coastal desert on earth receiving less than an inch of rain every 15-20 years. The Namib in Africa is also a coastal desert.
4. Polar Deserts
Two of the largest deserts are located in the polar areas: the Antarctic Polar Desert is 5.5 million square miles, covering the continent of Antarctica, and the Arctic Polar Desert is 5.4 million square miles, covering Alaska, Canada, Greenland, Iceland, Norway, Sweden, Finland and Russia. You won’t find sand but you will see snow dunes when there is substantial precipitation. In summer temperatures can reach 50 degrees but winter temperatures fall below freezing with annual rainfall of less than 10 inches. Plants are scattered and can vary in height up to four feet. Many are deciduous and some have sharp spiny leaves. Animals that live in this environment include jack rabbits, kangaroo rats, mice, and squirrels. Many are burrowers such as badger, fox, and coyote.
Where are Deserts located?
Deserts are located on every continent. Some of the largest deserts include the Antarctic Polar Desert and the Arctic Polar Dessert; Africa – the Sahara and Kalahari; Arabian Desert on the Arabian Peninsula; the Gobi in China and Mongolia; Patagonian Desert in Chile and Argentina; The Great Victoria Desert in Australia; Syrian Desert in Syria, Iraq and Jordan; and Great Basin Desert in the U.S. bounded by Mojave and Sonoran Deserts.
Why are Deserts important to protect?
Deserts cover 20% of the earth’s surface and despite their extreme conditions are home to one sixth of the world’s population. They play an important role in biodiversity supporting plants, animals, and humans. There are a number of minerals and metals that are found in deserts and extracted for their commercial value including nitrates, potassium, bauxite, copper, gold and diamonds. Deserts also contain 75% of the world’s known oil reserves. Desert plants can be used to create medicines and other beneficial pharmaceuticals. Desert sands also absorb and store carbon dioxide from the air.
When are deserts under threat?
Deserts are being threatened for many reasons. Climate change is impacting weather patterns and reducing snow packs and glaciers that provide freshwater to deserts. Human development of communities on the edges of the desert are eroding the desert habitat causing land degradation, desertification and loss of diversity, as well as contributing to evaporation and dust storms.
Excessive groundwater extracted from the desert to support communities is depleting the water faster than it can be recharged. This undermines the desert’s ability to support plants and wildlife. Military activities and four-wheel drive vehicles used for recreation damage desert environments. Plundering deserts for the extraction of minerals and oil can also damage these fragile environments. Animals grazing on the desert foliage can also cause irreparable damage.
Who is protecting Deserts?
There are several organizations that are protecting deserts. Defenders of Wildlife is a major national conservation organization focused solely on wildlife and habitat conservation and the safeguarding of biodiversity. They have been seeking to protect wildlife and the habitats since 1947.
World Wildlife Federation is preserving and protecting deserts within North America such as the Rio Grande/Rio Bravo River basin where they help to ensure there is enough water for the animal and plant species to thrive. WWF also has a program in the Arabian Highland Woodlands and Shrublands Ecoregion seeks to protect the natural habitat of endangered animals on the Arabian Peninsula in the Arab Emirate Fujairah where many wildlife species are being lost to land development and recreation. Nature Conservancy is actively protecting threatened plants and animals in desert environments.
How can we protect Deserts?
The threats to deserts are diverse including climate change, land development, recreational uses, and mineral and oil extraction to name a few. There are a number of things that individuals can do to help preserve and protect deserts. You can adopt an animal, actually it is a symbolic adoption where money is given to protect the habitat of the animal through non profit organizations. You can take action and send a message to government leaders. You can search the internet for “deserts under threat” to find something closer to home and ways to become involved. Be an advocate of “smart community development” so that deserts are not being paved over to become housing tracts. Support businesses and companies that take care of the environment and don’t pillage natural resources from less financially stable countries without concern for the state of the environment or local communities.