Biogeographic Regions of Arizona
Sonoran Desert Region
Covering a large portion of central and southern Arizona is the
Sonoran Desert Region. The geographic extent of this desert is
defined by the stately saguaro cactus, whose impressive trunk
can grow to a height of 50 feet or more. The Sonoran desert is
unlike most other desert regions in North America. Portions of the
desert receive a considerable amount of rainfall, much of it is
well-vegetated, and it has a rich collection of both plant and
animal species. In addition to the distinctive saguaro cactus,
other notable plant species include ocotillo, palo verde, cholla,
and, to the south, organ pipe cactus. The Sonoran Desert
landscape is especially beautiful during the spring
when flowers carpet the desert floor and the many shrubs and cacti are
in full bloom.
The following biotic communities can be seen in much of central and southern Arizona in the Sonoran Desert Region: Sonoran Desertscrub, Southern Arizona Riparian Woodland, Chaparral, Pinyon Pine - Juniper Woodland and Madrean Evergreen Woodland.