Shrub Desert
The Shrub desert of the midlatitudes supports a more diverse community of plants and animals. Associated with the midlatitude desert climate, more precipitation and cooler temperatures help support a more complete ground cover. This is especially true along dry stream beds where moisture is often more plentiful. Large cacti like the Saguaro cactus, and xerophytic shrubs are found in the Shrub desert of North America.
Figure 13.25 Joshua Tree National Park, California near Sheep Pass, 1962.
Courtesy USGS (Source)
Some xerophytic vegetation are widely spaced, and have extensive root systems to capture moisture in the soil. Others have waxy leaves or fleshy tissues to store moisture. Enlarged green stems like those found on cacti take over the function of leaves in photosynthesis. Some desert vegetation may shed parts of branches during extreme drought.
Deserts have been expanding worldwide in response to several natural and human-induced reasons. Learn more by "Digging Deeper into Desertification" or skip and continue reading.