Desert Diaries

Facts About Fires (Buffelgrass Style)

Photo: Mike Christy/Arizona Daily Star

Did you know that buffelgrass is one of our most serious environmental problems in the Tucson Basin? More specifically, it’s the invasion of buffelgrass in our city and the wildlands that surround our city. What’s at stake is much larger than the saguaros that stand on A Mountain.

The mustard yellow grass is buffelgrass. Photo: Aaryn Olsson

A smoldering cigarette tossed from a car window could light a roadside buffelgrass fire with potential to shut down I-10, cause accidents, and even take lives. A lightning strike on the buffelgrass infested slopes of the Santa Catalina Mountains could carry a wildfire up the mountain to higher elevation grasslands and forests, or down the mountain to the Catalina Foothills community, threatening the lives and property of the people who live there.

Photo: A.E. Araiza/Arizona Daily Star

In the desert, buffelgrass is filling in the empty space that separates trees, shrubs and cacti. This creates a continuous layer of fuel across the desert floor. As we saw on Tuesday night, fires fueled by buffelgrass kill saguaros. In fact, buffelgrass fires burn hot enough to kill most of our native desert plants, which are not adapted to fire, because fire is not a natural part of our desert ecosystem. In contrast, buffelgrass, which is native to the savannas of Africa, is a fire-adapted plant, and after every burn it comes back with renewed vigor.

Photo: Murphy Woodhouse/Arizona Daily Star

Even in the absence of fire, most native desert vegetation cannot survive competition with buffelgrass. Our long-lived saguaros will stand tall in a sea of buffelgrass, but those will likely be the very last. In dense patches of buffelgrass, you’ll find few young saguaros. Researchers aren’t exactly sure why, but it’s likely that saguaro seedlings are simply unable to compete with mature buffelgrass plants.

The fire on A mountain paints a picture of a possible future, one with far fewer saguaros and far more frequent fire, both within the city and in the wildlands surrounding the city. The battle to save our saguaros is ongoing. Until we reach a point where the abundance of buffelgrass has been reduced to levels that can be maintained with modest inputs of resources, we have our work cut out for ourselves. Help save saguaros today!

Written by Kim Franklin, Ph.D., ASDM Conservation Research Scientist