A Canadian scientist is exploring the link between historical volcanic activity and the saguaro cactus population of Kofa National Wildlife Refuge near Yuma. Maya Springhawk Robnett of the Arizona Science Desk reports…
Taly Dawn Drezner, a professor of biogeography at York University in Toronto, compared the values of historical spikes in volcanic activity to the age of saguaro cacti in Kofa National Wildlife Refuge. Drezner’s research shows the majority of saguaros established there began life during a time of especially tumultuous global geologic activity—starting at around 1883 when a massive volcano erupted in Indonesia.
From the late 1800s to the early 1900s, large-scale volcanic eruptions took place every few years. Drezner says the particulates and gases released into the atmosphere by the cluster of volcanic activity made the global climate temperate enough to allow saguaros on the other side of the world to survive infancy. Nearly all saguaros die within the first two years of life.
“The effects of a volcano may last only one or two years but, in fact, that’s exactly the critical window for saguaros," Drezner explains. "Those effects fade, the plant is likely already past the critical stage and can probably now survive with more adverse conditions.”
That means almost all the saguaros in Kofa are about the same age—123 years old, give or take, and all linked to this series of volcanic eruptions. Drezner says this is an example of the major effects slight variations in the climate can have on a single species and demonstrates climate change at work.
Dr. Drezner's research in the Ecological Society of America:
Below is an extended interview between Dr. Taly Dawn Drezner and the Arizona Science Desk’s Maya Springhawk Robnett.