NATURAL HISTORY OF THE FOUR NORTH AMERICAN DESERTS
February 11, 2026, 2:00-3:30 PM, -- Tubac Community Center, 50 Bridge Road -- Ed Madej
Ed Madej is a retired geographer and GIS specialist living in Ajo, Arizona. He completed his graduate education at the University of Georgia, and spent his career focusing on natural resources and cartography in Helena, Montana, working with government agencies, private business, and non-profits. Ed has a long-standing interest in the natural world, especially desert ecosystems and native vegetation, and, more recently, how these may be impacted by climate change. He has traveled extensively and spent time in a wide range of arid habitats, from the dry tundra of far north Alaska, to Death Valley, to the Galapagos Islands, and now makes his home in the Sonoran Desert.
This presentation will review the natural history of the four North American deserts, i.e., the Great Basin, the Mojave, the Chihuahuan, and the Sonoran. Although young in age (and small in size by world desert standards), the four deserts are biologically unique, and none more so than the Sonoran Desert, our only subtropical maritime desert.
The wide range of xeric habitats in the U.S. and Mexico stretch from sea level in Baja, with the largest collection of sand dunes on the continent, to the heights of some of the steepest mountains in North America and home to Bristle Cone Pines, among the oldest living plants on Earth.
The giant columnar Saguaro cacti of the Sonoran Desert, even though limited in their distribution, have become a popular icon representing the entire Southwest to millions of people.
The unique environments of these deserts have inspired an active movement to conserve them, resulting in two of the three largest protected desert areas on Earth, in the Mojave and the Sonoran deserts.