In-Migration

Since World War II, the Sunbelt of the U.S. Southwest and Northwest Mexico has been the setting for the largest in-migration in human history. A century and a half ago, indigenous communities still outnumbered European colonial communities, both in number and in the amount of land and water they managed. Then, families of European descent were still a minority in most parts of the region; today, the economic activities of the region are dominated by individuals who have lived in the region for less than a decade, if they "reside" here at all. The average resident of the Phoenix metropolitan area has lived there for less than five years, and has moved around within the area two or three times since arrival. Such trends are serious impediments to the development of a "sense of place," or to the will and wherewithal to protect unique features of a place. No wonder the scientists surveyed placed in-migration and rapid population change as the paramount threat to the region's uniqueness and biodiversity.

It is unlikely that most newcomers will glean much of the traditional community-based knowledge of the desert's limiting factors and diversity. The majority of immigrants from other regions in the U.S. and Canada are from more humid areas where water is less of a limiting factor; the same is true of those emigrating from central and southern Mexico, or from other areas of Latin America. Thus is it not merely the sheer numbers of recent immigrants that is of concern; it is also that their expectations of desert ecosystems are skewed by their movement from better-watered areas. They have seldom had sufficient contact with those land-based community members who have had to learn how to live within the desert's constraints.

From:
Nabhan, Gary Paul and Andrew R. Holdsworth. 1998. State of the Sonoran Desert Biome: Uniqueness, Biodiversity, Threats and the Adequacy of Protection in the Sonoran Bioregion. p.34-36. Tucson, Ariz.: The Wildlands Project.