PARENT SESSION
Oral Session #82: Urban Ecology.
Presiding: M. Cadenasso
Thursday, August 8. 9:00 AM to 11:30 AM. Grand Ballroom East, Radisson.
Survival evaluation of transplanted saguaros in an urban housing development and golf course development.
Harris, Lisa1, Funicelli, Carianne*,2, Pierson, Elizabeth1, 1 University of Arizona, Tucson, AZ2 Harris Environmental Group, Inc., Tucson, AZ
ABSTRACT- The giant saguaro cactus (Carnegiea gigantea) is a widespread and conspicuous component of Sonoran Desert vegetation occurring in southern Arizona, the southeastern tip of California, and northern Sonora, Mexico. The range of saguaros overlaps with many of the most rapidly growing urban areas in southern Arizona and the demand for land has increasingly lead to the development of prime saguaro habitat. Until recently, many residential developments in Tucson and elsewhere have been accomplished by the destruction of all vegetation on housing sites and the reintroduction of native and exotic vegetation after building has been completed. Public outcry over the destruction of saguaros has lead to the re-evaluation of this practice and the requirement of saguaro transplant in some development mitigation plans. Evaluation of saguaro transplant success is complicated by several factors. First, although transplanting saguaros is a common practice, few commercial salvage operations have kept statistics on transplant success. Second, even under natural field conditions, there is often a lag of 1 to 10 years between the time the plant is injured and the time of death as witnessed by the collpase of the plant. Transplanted saguaros must therefore be monitored over several years and survivorship compared to non-transplanted individuals. Studies of natural saguaro survivorship patterns show that mortality rates are height dependent, therefore evaluation of transplant success must be made by size class. This study measures the survival rate of transplanted saguaros at a golf course and housing development in Tucson, Arizona. Saguaro of various size categories have been monitored biannually since they were transplanted in 1995 and 1996 as part of environmental mitigation requirements specified in the development plan. The results of this study are intended to aid urban planners and natural resource managers to determine appropriate mitigation policies in areas where saguaros naturally occur and where urban development is planned.
KEY WORDS: saguaro, Carnegiea gigantea, transplant, urban development