The three oldest saguaros in my front yard were discussing the drought conditions. They were concerned because saguaro seeds need several consecutive days with moist soil to germinate and these conditions do not occur every year. In 2020, the “monsoon” i.e., the summer rains were minimal and so were the winter rains.
When looking across an expanse of desert containing many saguaros, one notices that there is not a continuous range of saguaro heights. Rather, there seems to be just a few “cohorts” of saguaro of similar heights. Ongoing Research in Saguaro National Park shows that “although the population of saguaros in Saguaro NP is quite healthy, establishment of young saguaros has nearly ceased since the early 1990s in nearly all habitats.” Also, “The effects of the current extended drought (>20 years) appears to be exacerbated by higher temperatures, which dry out soils and increase mortality of saguaros that are too small to store sufficient water. In rocky foothills, local microhabitat features such as slope, aspect, soil type, and features that affect the accumulation of water may slightly mitigate these factors.” Ironically, the researchers noted that the demise of many saguaros in the 1940 was due mainly to freezing temperatures at night.
For a detailed look at saguaros, see my article:
https://arizonadailyindependent.com/2014/03/30/saguaro-cactus-icon-of-the-sonoran-desert/
Note to readers:
Index with links to all my ADI articles: http://wp.me/P3SUNp-1pi
Visit my blog at: https://wryheat.wordpress.com/
My comprehensive 30-page essay on climate change: http://wp.me/P3SUNp-1bq
A shorter ADI version is at https://arizonadailyindependent.com/2013/08/01/climate-change-in-perspective/