The Saguaro Mapping Project: Final Report: Phase I

Christopherson, Gary; Holden, Mark; Turner, Raymond

In 1959, Dr. Raymond Turner established the first of what would become 13 saguaro plots in the Sonoran Desert. Over the next 45 years, he revisited each plot and recorded each saguaro’s location, height, nurse plant, and number of arms and buds, as well as the impact of frost, fire, disease, and birds and animals, including cattle grazing, on the health of the saguaro population. The Saguaro Mapping Project, Phase I, examined the 9 plots established outside the Tumamoc Hill study area. These plots, located across southern Arizona and northern Mexico, total 20.13 hectares and include 2,750 documented saguaros. A NASA Space Grant inaugurated work on the project in August 2003. The primary objective of the Saguaro Mapping Project, Phase I, was to enter Dr. Turner’s data into a GIS database which would allow computer mapping and analysis of each saguaro plot. Prior to the inception of the Saguaro Mapping Project, none of Dr. Turner’s data existed in such a database. He maintained his data in a variety of forms, from hand-written field books and notepads to Excel files and older computer tapes and printouts. He mapped his saguaro plots with a drafting table. The initial challenge of the project, then, was to organize the saguaro data from all these sources, including the hand-drafted maps, and standardize it into a single format from which a geodatabase could be built.