A Biotic Survey of Buehman, Espiritu, Youtcy and Roble Canyons in the Redington Pass Region, Arizona

Malusa, Jim

Bridging the Catlina and Rincon Mountains, Redington Pass is approximately 25 miles northeast of downtown Tucson. The lowest point of this 'saddle between the two mountain ranges is about 4000 feet. The highest elevations in the Catalinas and Rincons are, respectively, 9157 and 8666 feet. The relatively high elevation of the mountains provides around 25 inches of precipitation yearly. Much of this water rinds its way down through the canyons of Redington Pass. The westside canyons of the pass ultimately drain into the Santa Cruz River; the eastside flow into the San Pedro. This report summarizes a biological inventory of the riparian communities of four eastside canyons of Redington Pass. The study centers on Buehman Canyon, which with a water shed of 51.3 sq. mi, is the largest and best watered of the eastside canyons. This canyon, along with Espiritu, Roble and Youtcy canyons, were surveyed by Jim Malusa and Mark Porter on 18-20 October 1990. In the lower reaches of Beuhman and Espiritu Canyons are perennial pools with fish populations, while Youtcy and Roble canyon hold springs that probably flow during all but the most severe droughts. All four canyons intersect limestone bedrock, a feature that distinguishes them from all other Sonoran desert riparian areas. Plants were the focus of this study, in large part because of the ease of collection and identification. Even so, because many plant species can be identified to the species level with certainty when flowers and fruit are present, a moderate proportion of the native flora could not be identified. This means that the species listed in Appendix q underrepresents the true number of plant species in the study area; more would be found with more time spent in the Canyons, particularly in the late spring.