As saguaros across the Sonoran Desert suffer from the combined stresses of extreme heat and drought, researchers say these climate changes threaten the large saguaro forests we see across Southern Arizona and Northern Sonora. A new study finds that severely hot and dry weather dramatically increased saguaro mortality at two ends of the Sonoran Desert in 2020 and 2021 and that generally, the health of saguaros and other desert vegetation has declined significantly. The continued warming and drying threatens to irretrievably reduce the scale of and, in some cases, possibly eliminate the large saguaro forests, the researchers say.