Size: 41,300 hectares
Elevation range: 610–2,621 meters
Situated to the east and west of Tucson, Arizona, the two distinct districts of Saguaro National Park encompass a tremendous amount of ecological diversity. To the east, the higher Rincon peaks comprise the park's "sky islands." Though surrounded by desert, the montane habitats found here support boreal species more commonly found in northern latitudes. Climate change is a strong concern here, as there are no higher habitats into which forest species can migrate to escape predicted increases in temperature.
The saguaro cactus (Carnegiea gigantea), which gives the park its name, grows only in the Sonoran Desert of the U.S. and Mexico. The spread of invasive exotic buffelgrass (Cenchrus ciliaris) in the park has introduced wildfire to a desert landscape whose flora did not evolve with it. Buffelgrass poses a major threat to the future of the saguaro here.
With its wide elevation range, Saguaro National Park lies in both the Sonoran Desert and Apache Highlands ecoregions. The park's Rincon Mountain District (RMD) contains five biomes: thornscrub, semi-desert grassland, Madrean evergreen woodland, and temperate forest. Average annual precipitation at the RMD is 13.3 inches (338 mm). The Tucson Mountain District (TMD) contains three biomes: desert, thornscrub, and semi-desert grassland. Average annual precipitation at the TMD is 13.3 inches (338 mm).
The Sonoran Desert Network monitors air quality, climate, groundwater, landbirds, springs, seeps, and tinajas, and vegetation and soils at Saguaro National Park. The results of this work can be found in a variety of publications and other information. The network also maintains species lists for the park.
Last updated: November 1, 2022