"A warming world means an invasive grass is threatening the famous saguaro
Cactuses cover a hillside in Saguaro National Park in Arizona."
"TUCSON — The giant saguaro, an icon of the American West, is beloved in this state. Arms raised in a perpetual “hello there,” the saguaro covers the desert wilderness and thrives in cities. Its silhouette appears in fine art and on restaurant walls; businesses and schools carry its name. Arizona state law protects the plant, and it is revered by the native Tohono O’odham tribe.
The largest cactus in the United States, the saguaro is distinct, visually and biologically. A mature saguaro can grow to 40 feet and weigh a ton after soaking up rainwater. Supported by its wood skeleton, the saguaro can sprout dozens of arms. Sometimes the arms are curled; if two are growing side by side, they’re often hugging.
The saguaro grows in just one part of the world: in the Sonoran Desert of Arizona; northern Mexico; a smidgen of California; and most prolifically in a mountainous swath that flows west from Tucson to the California border. It’s a landscape of rock, hard sand and open blue sky, and the saguaro has been part of it for 10,000 years.
And now, a changing climate is raising concerns about how the saguaro will survive the 21st century in an environment that’s hot and getting hotter, dry and getting drier. In a climate wake-up call, drought and record-breaking heat in 2020 contributed to wildfires that killed thousands of saguaros."