Meet the saguaro – the star of many an Arizona postcard, silhouetted against a red desert sunset. This plant is huge. In fact, Carnegiea gigantea is the largest cactus species in the United States, regularly reaching heights as tall as 40 feet or more. The spiny giants are native to the Sonoran Desert, and this particular beauty lives in Arizona’s Saguaro National Park in Tucson. Not much threatens the saguaro, as long as its native habitat remains stable. Birds and other critters rely on it for food and shelter, but they live harmoniously with the tree-like cactus. The extreme temperatures of the desert climate also pose little threat to the saguaro, which is adapted to endure cold winters and blazing summers. This desert giant has a surprising foe: a nonnative, invasive grass. Buffelgrass was purposefully introduced to Tucson, AZ rangelands in the 1930s as forage for cattle, and it is changing ecosystem dynamics in some desert habitats. The unwelcome grass serves as a thick carpet of fuel for fires that would not usually burn in an ecosystem otherwise dominated by cacti and scattered shrubs. While the saguaro cactus is resilient within a balanced ecosystem, it is no match for fire. That is why Saguaro National Park is working diligently to slow the spread of the grass. They began by pulling it up by hand in the 1990s, but this proved to be too difficult because of the extent of the infestation. Now they use a combination of manual and chemical treatments to combat the persistent invader.
Learn more about what the park is doing to control to buffelgrass, as well as how you can help here: https://www.nps.gov/sagu/learn/nature/buffelgrass.htm
Here are two links to fun facts about the saguaro that will make you love it even more: https://www.tpl.org/blog/saguaro-national-park-cactus-facts#sm.001lx4rg0xu7dy611v51lplggbyho and http://www.sciencefriday.com/articles/11-things-you-didnt-know-about-saguaro-cacti/
Learn more about what climate change could mean for the saguaro cactus (more on this in a future post, as well): https://www.nature.nps.gov/ParkScience/archive/PDF/Article_PDFs/ParkScience28(1)Spring2011_69-72_Swann_et_al_2796.pdf