By John Edwards

Oct. 13, 2008—Sprawling across the scorching Sonoran Desert on the outskirts of Tucson, Ariz., Saguaro National Park is home to a forest of 1.6 million saguaros—giant cacti found nowhere else on Earth. The iconic plants, living symbols of the U.S. Southwest, are increasingly threatened by encroaching civilization, as well as a variety of natural diseases and predators. "You might think that something that can live to 150 years and stand over 25 feet tall wouldn't need much protection," says Chief Ranger Bob Love, "but you would be wrong."

Love is one of a growing number of nature and wildlife experts who are hoping that radio frequency identification technology can help them get the upper hand in a never-ending war against thieves, vandals and the forces of nature itself. While RFID isn't destined to replace other popular wireless tracking technologies, such as terrestrial radiolocation and GPS, the technology has unique attributes that make it an attractive tool for monitoring natural assets—both living and geologic—over extended periods of time at a relatively modest cost.

The cacti of Saguaro National Park are increasingly threatened by encroaching civilization.

Government agencies, conservation groups and other outdoors-focused organizations are discovering that RFID-based monitoring and tracking systems provide a great deal of versatility. Some RFID applications include the tagging and tracking of endangered species to determine how environmental changes are affecting their habitats. Other projects, such as the one at Saguaro National Park, are security projects designed to keep precious on-site assets safe. Still other outdoor projects aim to control and manage herds, or to answer questions about local geology.