What would you say if someone asked you what the greatest threat to the beautiful Sonoran Desert scenery we enjoy every day?
Would it be climate change, with drier, hotter summers becoming the new normal and water levels declining?
Would it be new urban developments, with prime real estate clearcutting saguaro vistas?
While it’s difficult to predict the future’s biggest challenges, one of the scariest threats is something most of us pass by without even a second glance: nonnative plants.
The Sonoran Desert is the most biodiverse desert on earth. It’s not just a miracle of adaptation to extreme weather; it’s teeming with life, from the desert millipede to the organ pipe cactus. However, such a unique, carefully balanced ecosystem also leaves itself vulnerable to invasion. Plants like buffelgrass, fountain grass, and stinknet are examples of exotic species that have taken the fire ecology of their native lands in the African savannah into a region where wildfire has not existed. Our desert plants are meant to be spaced far apart, providing natural fuel breaks that would stop a fire from spreading as it might in a heavily forested area. However, when an introduced, highly flammable plant takes hold and turns those fuel breaks into fuel blankets, you have a serious problem.
Buffelgrass, the most infamous desert invader, burns at more than 1,400 degrees. That’s nearly three times hotter than native grasses can burn. Buffelgrass was originally brought to Arizona for erosion control and grazing until it spread far beyond any farm or mine. But buffelgrass’s cousin, fountain grass, was imported for another reason: landscaping: similar DNA, different cause of introduction.
Fountain grass, also known as Pennisetum setaceum, is named after the graceful fountain flow it resembles. The irony here is that instead of providing water, this plant colonizes river washes and robs native flora and fauna of the precious water resources they need. An example is Saguaro National Park East, where fountain grass populations have impacted native amphibians’ ability to thrive in riparian areas.
Despite being identified as a highly invasive species in Arizona by the US Forest Service and declared illegal to sell and/or import by the Arizona Department of Agriculture’s “Noxious Weeds List,” fountain grass is still easy to find in landscapes in Pima County. Why? Because it takes time to stop people from displaying pretty things. Nurseries think they’ve found a convenient loophole, selling supposedly “sterile” fountain grass, but these plants still produce viable seeds that can disperse into desert habitats.
There are countless challenges in the battle against invasive species, particularly mitigating plant populations that have spread exponentially over acres of land. Comparatively speaking, replacing the row of fountain grass plants in your front yard with deer grass or Arizona cotton top is easy. The first step is recognizing fountain grass, with its long flowing bottlebrush seed heads and densely bunched leaves. In a younger plant, the seed heads are white and purple-tinted and can be up to one foot long.
Plants can be removed mechanically by digging out the roots using a digging bar or shovel. Herbicide can also be applied when the plant is at least 50% green, and glyphosate has been proven to be the most effective chemical on this plant. And if you spot fountain grass in the Catalina Foothills or other unincorporated Pima County land that you do not own, consider reporting it on the Pima County Department of Environmental Quality website (https://pima-pima-county-department-of-environmental-quality.app.transform.civicplus.com/forms/32460). Yes, the form says “buffelgrass complaints” but the DEQ has confirmed that they treat fountain grass and buffelgrass the same, as serious invasive threats. The DEQ will reach out to the landowner and explain the invasive nature of this plant, as well as the fire risk. More often than not, it’s just a matter of not knowing there was even a problem with this harmless-looking pretty grass, and the landowner will recognize their best interest is to remove this fire risk.
Is there another state with such a deep connection to its most famous plant as Arizona and the saguaro cactus? What would happen to our sense of identity if the saguaro was no more? Or, looking at it from a more economic perspective, what would happen to tourism, property values, insurance costs due to fire risk, and so on? Protecting the saguaro and the ecosystem is a vital part of should be a top priority for everyone living in the Sonoran Desert. To protect that saguaro, one has to know the anti-saguaro: invasive plants.
To learn more about buffelgrass, fountain grass, stinknet, and more, visit the Sonoran Desert Cooperative Weed Management Area at https://sdcwma.org/. To join a volunteer invasive species removal event, go to buffelgrass.org.
The Sonoran Desert is the most biodiverse desert on earth, from the desert millipede to the organ pipe cactus.