Flora and Fauna News

Saguaros Face Bounty and Danger

By Michael Plagens
Sonoran Desert Sciences

With an abundance of rainfall in mid January 2010 and then three weekends with rainy weather beginning in mid February Saguaro Cacti across the Sonoran Desert have stored tons of water for use during the next several months as the desert heats up. The water will allow lots of photosynthetic activity between now and mid-May when the flowers begin opening. The resulting energy and food will be stored by the cactus for use in developing fruit and for new growth. A good fruit crop will ensure healthy populations of White-winged Doves that gorge on the fruit pulp.

The saguaro stores water within the spongy tissue of its columns with the accordianlike ribs expanding as the reservoir fills up. But as any desert hiker knows, a large quantity of water is heavy. Add to this a typically windy month ahead and the top heavy cactus rooted in moist loose soil runs a serious risk of toppling. Injuries caused by wind damage are quickly exploited by insects, fungi, and bacteria with the death of the cactus likely.

Saguaro Cactus, Cereus giganteus.
Photo by Mike Plagens