Abiotic factors in desert

Desert ecosystem is characterized by arid conditions with low precipitation. It is largely barren, dry, and abandoned land without flora and fauna in the sand. It might be cold or hot. A Desert ecosystem is a community of non-living and living organisms living and interacting with each other in an abandoned environment. It’s the interaction of abiotic and biotic components of the desert system. Abiotic factors in desert like sunlight, temperature, wind, etc have a profound influence on the survival and adaptation of species in desert ecosystems. Organisms in these environments have evolved strategies to cope with these abiotic factors (1).

Abiotic factors

Abiotic factors are the non-living part of an ecosystem that shapes its surroundings. The several abiotic factors present in the desert ecosystem are mentioned below-

1. Climate and Temperature

Deserts are known for their arid climate. They receive very little rainfall. This low rainfall affects the survival of various flora and fauna. They often experience extreme temperature fluctuations, with tremendous heat in the daytime and cold in the nighttime. Organisms in the desert adapt to these huge temperature variations to survive. Based on the combination of low rainfall and different average temperatures, three types of desert could be found. They are-

Type of desert              Location and main climatic characteristics
Hot and dry desert Found between 15 and 30 degrees north and south of the equator along the Tropic of Cancer and the Tropic of Capricorn. The world’s largest hot desert, the Sahara, is a subtropical desert in North Africa. Other subtropical deserts are the Kalahari Desert in Southern Africa and the Tanami Desert in North Australia. The extreme maximum temperature ranges from 43.5 to 49 degrees C, and rainfall is less than 250 mm per year.
Cold or temperate desert The major deserts of this type include the Sagebrush of Utah, Montana, and the Great Basin of North America. The Gobi, and TaklaMakan deserts of Northern Asia. The mean winter temperature is between -2 to 4 degrees C and the mean summer temperature is between 21-26 degrees C, with cold winters with snowfall.
Coastal desert The Atacama desert of South America on the Pacific shores of Chile is a coastal desert and one of the driest places on earth. The average rainfall measures 80-130 mm in many areas. A coastal desert is almost rainless, yet damp with fog.

2. Precipitation

It is one of the most limited features in the desert ecosystem. Desert typically receives very little rainfall, with annual precipitation measuring less than 250 millimeters.

Atacama desert in South America is among one of the driest places on earth and receives only a few millimeters of rainfall per year.

Desert organisms have developed a range of adaptations to survive in low-rainfall environments. These strategies include water-conserving techniques like in humps of camels, specialized water storage tissues like in cactus plants found in deserts, etc. 

3. Soil composition and structure

Most desert soils are called Aridsoils (very dry soils). These soils are CaCO3-containing soils of arid regions that exhibit at least some subsurface horizon development. They are characterized by being dry most of the year with limited leaching.

The climate in which arid soils occur also restricts soil weathering processes. Aridsoil contains subsurface horizons in which clays, calcium carbonate, silica, salts, and gypsum have accumulated.

In hot deserts, soils are coarse-textured, shallow, rocky, or gravely with good drainage and have no subsurface water. They are coarse because there is less chemical weathering. The finer dust and sand particles are blown elsewhere, leaving heavier pieces behind. In dry regions of the Sahara and Australian desert, the soil orders are called Entisols. They are new soils, like dunes, which are too dry for any major soil horizon development (2).

4. Geology and Topography

Desert ecosystems contain various types of unique geological and topographical features. A few of them are-

  • Desert flats

Many deserts are covered with a layer of desert pavement, which consists of small, closely packed rocks and pebbles. This surface feature helps to reduce erosion and water loss by preventing wind and water from carrying away loose sand and soil.

  • Sand dunes

These are prominent features in many desert landscapes. Dunes can be different in size and shape and often move as a result of wind.

  • Water-based landforms

In desert regions with occasional rainfall, wadis form which are dry river beds that quickly become active during rains. They store water. Oasis are areas within deserts where underground water surfaces or where water from springs provides a reliable water source.

  •   Mountains and hills

Desert regions can also contain mountain ranges and hills, which influence the local climate by affecting wind patterns and creating rain shadows (3).

5. Wind and air quality

The air in desert biomes lacks moisture and is extremely dry because deserts are located far from the seas and oceans, or they fall in the rain shadow area or leeward side of the mountains.

As most deserts lie in subtropical high-pressure areas, the winds blow faster, sweeping more than half a mile every minute. Since there are no trees and plants to block the winds and no plant roots and organic matter, the fast-moving winds blow sand and dust for long distances. This causes erosion of the land surface by causing deflation and resulting in the formation of desert pavements, which are eroded land plains consisting of coarse rock fragments. Hot, subtropical deserts have the characteristic feature of sand hills called dunes. These storms can be aggressive, covering farms and fields and affecting towns and cities (3).

6. Salinity and mineral content

Deserts have typically low precipitation which leads to the accumulation of salts in the soil. This results in high salinity levels in desert soils, making it challenging for plants to grow. Desert soils may also have high mineral content due to the weathering of rocks and minerals in the arid environment. Some common minerals found are quartz, feldspar, gypsum, and halite (4).

7. Sunlight

Sunlight is arguably the most vital abiotic component of the Desert ecosystem, especially for its role in the sustenance of both ecological processes and environmental conditions.

The importance of sunlight in deserts includes; its contribution to photosynthesis, temperature and climate, evaporation, hydrological cycling, and adaptation of desert plants and animals. Solar radiation in the form of light, is an essential ingredient for photosynthesis; the process whereby plants utilize light energy to power a series of photochemical reactions that transform carbon dioxide and water into oxygen and glucose (5).

Human impact on abiotic factors of the desert ecosystem

The Human Effects on deserts have been going on for quite some time. The main cause of this negative effect on deserts is human interactions. 

  • Interactions like driving through the desert, leaving tracks, and destroying vegetation. 
  • Also, water mining from reservoirs, military exercises (mainly atomic testing), and trenching involved with pipelines of gas, oil, and water have made grounds unstable and almost barren.
  • These effects have caused some animal species to go on the endangered species list ( like the Gazelle, the Oryx, the Addax, the Arabian Tahr, the Barbary sheep, and the Asian Houbara Bustard).
  • The glacier melting problem is also a problem for the desert’s ecosystem. Deserts like the Atacama and the Monte in South America will suffer the most and have their rivers run dry (6).

Q&A

1. What are 2 abiotic factors you can find in a desert ecosystem?

Two abiotic factors that we can find in desert ecosystems are

  • Temperature
  • Sunlight

2. What are 3 biotic factors in a desert ecosystem?

Three biotic factors in a desert are xerophytes (desert plants) and xerocoles (desert animals). Halophytes are also present, which show a high tolerance to salty conditions.

3. What are the 5 abiotic factors in every desert ecosystem?

The five abiotic factors in desert ecosystems are

  • Temperature
  • Climate
  • Precipitation
  • Soil
  • Sunlight

4. What are the abiotic factors of the cold desert?

Abiotic factors in cold deserts are low precipitation, extreme temperatures (both hot and cold), lack of humidity, sandy and rocky soils, and exposed bedrock.

Summary

  • The desert ecosystem is the driest ecosystem on the planet.
  • The desert ecosystem is a group of living and nonliving things that live together and interact with each other in a desert.
  • Deserts get seasonal rain that lasts for a short time (just around 25 to 30 centimeters).
  • This type of ecosystem is very hot or very cold at night and day. 
  • It’s hard to live in a desert ecosystem. But deserts have a lot of different animals and plants, even though they look like they don’t. 
  • Desert ecosystem is a combination of various biotic and abiotic factors.

References

  • D.R.Khullar.ISC Geography.Kalyani Publishers, Kolkata.Chapter 25-The Biosphere, Page no-370-372.
  • Binay Karna.Lucent’s General Knowledge.Lucent Publication, Patna.Chapter 04-Environment, Page no-176-77.

Written By: Ankita Gangopadhaya