Background:
The San Rafael State Natural Area (SRSNA), owned and managed by Arizona State Parks, is approximately 3,500 acres in size and consists of short grass prairie with oak woodlands at higher elevations. The headwaters of the Santa Cruz River, dominated by mature Fremont cottonwood (Populus fremontii) and Goodding willow (Salix gooddingii), bisects the area from north to south.  In May 2007, a human-caused fire occurred within the riparian corridor and adjacent uplands.  Arizona State Parks determined that approximately 600 acres burned on the SRSNA during this event.  In 2008, a complete inventory of trees (live and dead) was conducted along the riparian corridor to evaluate post-fire tree survivorship.

Location:
The SRSNA is located within the San Rafael Valley, between the Patagonia Mountains and the Huachuca Mountains, approximately 90 miles southeast of Tucson, Arizona. 

Approach:
The SRSNA portion of the Santa Cruz River riparian corridor is comprised of six sub-watersheds and the main channel of the Santa Cruz River.  We located all live and dead (snag) trees within each area, and measured species composition and tree diameter.  For each snag, fire-related death was determined based on evidence observed in the field (e.g., sloughing bark, trunk girdling) and regeneration of live stems (e.g., coppice sprouting, root sprouting) was noted if present.

Benefits:
Fire frequency and severity have increased in southwestern riparian areas in recent years, but the role of fire in these systems is not well understood.  Data on the response of native riparian plants to fire in the southwest are also limited. The 2007 fire on the SRSNA presented an opportunity to evaluate the short-term response of riparian vegetation to fire within two distinct areas: the wetter, main channel of the Santa Cruz River and the drier, more terrestrial sub-watersheds.  Collected data will provide important information on post-fire survival of native woody plants, such as Fremont cottonwood and Goodding willow, in southeastern Arizona. 

For more information contact:
Angela Stingelin, Arizona Game and Fish Department
5000 W. Carefree Highway Phoenix, AZ 85086-5000 
Phone: (520) 742-1911             Email: astingelin@azgfd.gov

Michael Ingraldi, Ph.D., Arizona Game and Fish Department
5000 W. Carefree Highway Phoenix, AZ 85086-5000 
Phone: (928) 532-5625             E-mail: mingraldi@frontiernet.net