Sonoran Desert
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Introduction
Location
The Sonoran Desert as currently defined covers approximately 200,000 square miles (520,000 sq. km- 100,000 square miles of land and 100,000 square miles of sea) and includes much of the state of Sonora, Mexico, most of the southern half of Arizona, southeastern California, most of the Baja California peninsula, and the islands of the Gulf of California. Its southern third straddles 30° north latitude and is a horse latitude desert; the rest is rain shadow desert. It is lush in comparison to most other deserts.
Landscape characteristics
The visually dominant elements of the landscape are two life forms that distinguish the Sonoran Desert from the other North American deserts: legume trees and large columnar cacti. This desert also supports many other life forms, encompassing a rich spectrum of some 2000 species of plants, 550 species of vertebrates, and unknown thousands of invertebrate species.
Climate
The amount and seasonality of rainfall are defining characteristics of the Sonoran Desert. Much of the area has a bi-seasonal rainfall pattern, though even during the rainy seasons most days are sunny. From December to March frontal storms originating in the North Pacific occasionally bring widespread, gentle rain to the northwestern two-thirds. From July to mid-September, the summer monsoon brings surges of wet tropical air and localized deluges in the form of violent thunderstorms to the southeastern two-thirds. So distinct are the characters of the two types of rainfall that Sonoran residents have different Spanish terms for them. The winter rains are equipatas (derived from the Yaqui-Mayo word for rain, quepa), the summer rains are las aguas ("the waters" in Spanish).
Distinguishing characteristics
The Sonoran Desert prominently differs from the other three deserts of North America in having mild winters. Most of the area rarely experiences frost, and the biota are partly tropical in origin. Many of the perennial plants and animals are derived from ancestors in the tropical thornscrub to the south, their life cycles attuned to the brief summer rainy season. The winter rains, when ample, support great populations of annuals (which make up nearly half of the species of our plants). Some of the plants and animals are opportunistic, growing or reproducing after significant rainfall in any season.
Subdivisions of the Sonoran Desert
The Sonoran Desert has beed divided into 7 subdivisions based on vegetation.
Further Reading
- Biomes & Communities of the Sonoran Desert, Arizona-Sonoran Desert Museum.
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Disclaimer: This article is taken wholly from, or contains information that was originally published by, the Arizona-Sonora Desert Museum. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the Arizona-Sonora Desert Museum should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content. |
[[category:|Sonoran Desert]]