The Physical Environment
                                          Contents | Glossary | Atlas |  Index | TPE Today | Google Earth | Search

Earth Biomes

The Desert Biome 

The desert biome has the lightest cover of plants of any biome. Lack of moisture prevents plants from establishing themselves in this harsh climate. Many unique adaptations to the extreme heat and lack of moisture enable some plants to survive. Plants adapted to drought are called xerophytes. Aridisol soils, common to deserts, are typically coarse, lack much organic material, and are often weakly developed.

Dry Desert

The dry deserts are typically found in subtropical latitudes and are produced by subsidence associated with the eastern sides of the subtropical high. These are extremely dry regions, some places hardly receiving any measurable precipitation during the year. Plant cover is non-existent over much of the dry desert.


wpe2.jpg (6311 bytes)Figure 13.23 Grand Erg Occidental Desert,  Algeria
(Photo credit: J.Van Acker, FAO Used with permission)

Like many dry deserts, a layer of coarse material blankets the surface. This "desert pavement" protects the underlying surface from erosion. When disturbed, wind easily dislodges particles and transports them away in a process called deflation. This makes the establishment of plants very difficult.

Oasis_Mauritania_I_Balderi_FAO_18834_small.jpg (13041 bytes)

Figure 13.24 Desert encroaching on desert oasis  (Photo credit: Mauritania. I.Balderi,FAO Used with permission)

Plants occur only under the most favorable microclimatic settings like those surrounding an oasis. Oases are created where the water table is near the surface. Groundwater can be easily extracted to support vegetation and wildlife.

Plant growth and reproduction are quite slow under desert conditions. Surface erosion by wind or water restricts the establishment of plants. Infrequent storms causes water to sweep across the barren surface carrying away massive amounts of material along with plants. The rapid movement of sand dunes covers and prevents the establishment of a plant cover too.

Previous | Continue    

Contents |Glossary | Atlas Index  |  Blog | Podcast | Google Earth | Search Updates | Top of page

About TPE | Who's Used TPE |  Podcast

Please contact the author for inquiries, permissions, corrections or other feedback.

For Citation: Ritter, Michael E. The Physical Environment: an Introduction to Physical Geography.
2006. Date visited.  ../title_page.html

Michael Ritter (tpeauthor@mac.com)

Help keep this site available by donating through PayPal.