HOTTEST IN HISTORY
Arizona’s saguaros are dying. According to the 2020 Saguaro Census, the Saguaro National Park estimates they have over 2.1 million saguaros in the park. However, Juarez estimates that 1,200 saguaros died in 2023 alone. Experts believe that the cause of this is extreme weather.
Data compiled by The National Weather Service Phoenix finds that summer 2023 is the twentieth hottest summer in Arizona’s history.
the saguaro cactus (green)
While intense heat plays a part in the death of the saguaro, it isn’t the main culprit. Dr. Tania Hernandez, a research scientist at Desert Botanical Garden, believes Arizona’s drought and lack of monsoon rains are the most significant reasons they die.
“Based on my personal observations and other people’s observations, is that we notice that more plants are dying. We notice that extreme heat and the lack of monsoon rain causes the plants to die.”
The National Weather Service Phoenix also finds that summer 2023 is the tenth driest summer since 1895, with about 2.46” of rain. Compared to summer 2022, with about 6.21” of rain.
While cacti don’t need much water, they have limits. According to the National Park Service, the mass of a saguaro contains about 75%-95% water.
If saguaro’s shallow roots don’t have access to water, Hernandez explains that they won’t be able to do certain things, such as produce photosynthesis.
“Unlike animals like us, plants don’t move. When you are hot, you can move and get shade, but plants cannot. The problem for plants is that it is extremely hot, and if they can’t cool down, they stop performing photosynthesis; they stop breathing.”
There is not enough data to predict what next summer will hold. Hernandez predicts that more saguaros will die as temperatures rise in the future.
