Because of the relatively hard conditions, the pre-Columbian people in this region developed distinct cultures and subsistence farming patterns. The region has only 120 mm (4.7 in) to 160 mm (6.3 in) of annual precipitation. The sparse rainfall feeds seasonal creeks and waterholes.[3]
The term was introduced by American anthropologist Gary Paul Nabhan in 1985,[4] building on prior work by anthropologists A. L. Kroeber and Paul Kirchhoff to identify a "true cultural entity" for the desert region. Kirchhoff first introduced the term 'Arid America' in 1954, and wrote: "I propose for that of the gatherers the name 'Arid America' and 'Arid American Culture,' and for that of the farmers 'Oasis America' and 'American Oasis Culture'".[5]
Mexican anthropologist Guillermo Bonfil Batalla notes that although the distinction between Aridoamerica and Mesoamerica is "useful for understanding the general history of precolonial Mexico," that the boundary between the two should not be conceptualized as "a barrier that separated two radically different worlds, but, rather, as a variable limit between climatic regions." The inhabitants of Aridoamerica lived on "an unstable and fluctuating frontier" and were in "constant relations with the civilizations to the south."[6]
Despite dry conditions, Aridoamerica boasts the greatest diversity of wild and domesticated tepary beans (Phaseolus acutifolius) and is a possible site of their domestication.[1]Maize cultivation reached Aridoamerica by about 2100 BCE.[8] Archaeologists disagree whether the plant was introduced by Uto-Aztecan migrants from Mesoamerica or spread either northward or southward from other groups by cultural borrowing.[8]
In Baja California, fishing and hunting provided food, as did harvesting acorns, nopal, pine nuts, and other native plants.[9]
Historically, people of Aridoamerica coppiced willows, that is, tree trunks were cut to a stump to encourage the growth of slender shoots. These willow shoots were woven tightly to produce waterproof, cooking baskets. Fire-heated rocks were plunged into a gruel in the baskets to cook.[3]
Deserts
The elevation in the Chihuahuan Desert varies from 1970 to 5500 feet, as there are several smaller mountain ranges contained in the area, namely the San Andres, Doña Anas, and Franklin Mountains. The Chihuahuan is a "rain shadow" desert, formed between two mountain ranges (the Sierra Madre Occidental on the west and the Sierra Madre Oriental on the east) which block oceanic precipitation from reaching the area.[10] The Chihuahuan Desert is considered the "most biologically diverse desert in the Western Hemisphere and one of the most diverse in the world", and includes more species of cacti than any other desert in the world.[11] The most prolific plants in this region are agave, yucca, and creosote bushes,[12] in addition to the ubiquitous presence of various cacti species.
When people think of the desert southwest, the landscape of the Sonoran Desert is what mostly comes to mind.[12] The Sonoran Desert makes up the southwestern portion of the Southwest. Rainfall averages between 4–12 inches per year, and the desert's most widely known inhabitant is the saguaro cactus, which is unique to the desert.[13][14] It is bounded on the northwest by the Mojave Desert, to the north by the Colorado Plateau and to the east by the Arizona Mountains forests and the Chihuahuan Desert.[15] Aside from the trademark saguaro, the desert has the most diverse plant life of any desert in the world,[13] and includes many other species of cacti, including the organ-pipe, senita, prickly pear, barrel, fishhook, hedgehog, cholla, silver dollar, and jojoba.[13][14]
The most northwest portion of Aridoamerica is covered by the Mojave Desert. In terms of topography, the Mojave is very similar to the Great Basin Desert, which lies just to its north.[12] The Mojave gets less than six inches of rain annually, and its elevation ranges from 3000 to 6000 feet above sea level.[16] The most prolific vegetation is the tall Joshua tree, which grow as tall as 40 feet, and are thought to live almost 1000 years.[14] Other major vegetation includes the Parry saltbush and the Mojave sage, both only found in the Mojave, as well as the creosote bush.[17]
Other reptiles in the region include lizards and turtles. Lizards are highly represented in the region, the most distinctive denizen being the Gila monster, native only to the American Southwest and the state of Sonora in Mexico. Other lizards include: Sonoran collared lizard (Crotaphytus nebrius); several types of geckos, including western banded gecko (Coleonyx variegatus), the barefoot banded gecko (Coleonyx switaki), and the Mediterranean house gecko (Hemidactylus turcicus), the latter species being non-native to the region and confined to developed areas; the desert iguana (Dipsosaurus dorsalis); the chuckwalla (Sauromalus ater); the greater earless lizard (Cophosaurus texanus scitulus); several sub-species of horned lizards (Phrynosoma); numerous species of spiny lizards (Sceloporus); Gilbert's skink (Plestiodon gilberti); the western skink (Plestiodon skiltonianus); Trans-Pecos striped whiptail (Aspidoscelis inornata heptagrammus); and the Arizona night lizard (Xantusia arizonae).[35] Turtles are less numerous than their other reptilian counterparts, but several are found in the region, including: the western painted turtle (Chrysemys picta bellii); the Rio Grande cooter (Pseudemys gorzugi); the desert box turtle (Terrapene ornata luteola); the Big Bend slider (Trachemys gaigeae gaigeae); the Sonora mud turtle (Kinosternon sonoriense); and the desert tortoise (Gopherus agassizii).[36]
^Paul Kirchhoff, "Gatherers and farmers in the Greater Southwest: a problem in classification", in American Anthropologist, 56 (1954) (Special Southwest Issue), pp. 529–50, see map p. 544.
Robery A. Bye; Edelmira Linares (2007). "9". In Carrasco, David (ed.). Cave, City, and Eagle's Nest: An Interpretive Journey through the Mapa de Cuauhtinchan No. 2. Albuquerque: University of New Mexico. pp. 255–280. ISBN978-0-8263-4283-6. Retrieved 16 November 2015.