|Close up of some desert pavement. Notice how the rocks are closely interconnected, often like a puzzle. This results in rainwater not penetrating the soil and instead running off. Plant and other live are nearly absent to areas like this.|
In our previous entry we discussed desert soil horizons, and if you were wondering, desert pavement is part of the A horizon. Soil horizons are extremely important in determining where water accumulates and therefore where and what types of plants grow. Desert pavement, as mentioned before, prevents water from penetrating deep into the soil due to its hard pavement like surface. Typically, desert pavement also indicates underlying thick layers of caliche, both of which can strongly impede water and plant roots from penetrating. Water may only penetrate a few centimeters deep, even after a good rain, and many years may pass between times where there is enough rainfall to penetrate to adequate depths to support plant life. Outside of the pavement though water penetrates more often and a lot deeper as evidenced by obviously thicker vegetation. Every five or so years through there is significant rainfall to penetrate deeper into desert pavement soils and short lived flowers can color the normally black desert ground yellow.
|Normally black and barren desert pavement covered with wildflowers after strong winter rainfall. Picture from:http://www.desertmuseum.org/programs/flw_mohave.php|