Cactus Habitat: Sonoran Desert
The Sonoran Desert is the most biologically diverse of the four US deserts. It represents the northernmost end of the range for many Mexican cactus species, such as saguaro, organ pipe, and some Mammillaria—and the only place these cacti can be found in the US. A variety of elevations, providing different average temperature ranges, also contributes to the Sonoran Desert's species diversity. The desert experiences two rainy seasons: one in the summer that provides most of the soaking rainfall cacti need during their growing season, and one in the winter that is less intense but more widespread.
Threats to Sonoran Desert cactus populations include development, off-road vehicle recreation, and nonnative plants that not only compete for scarce resources but also increase the risk of fire. Desert cacti are not fire-adapted and entire populations of the slow-growing plants can be decimated by wildfire. Poaching of plants for horticultural trade is a concern, as is vandalism of saguaros.