Buffelgrass. It’s a dry topic, literally. Buffelgrass is typically bone-dry nine months of the year, greening up only during the monsoon season. And when this drought-hardy bunchgrass is dry, it poses a serious fire risk. That’s why Pima County was awarded a $3.4 million dollar matching grant from the Federal Emergency Management Association (FEMA) to protect critical infrastructure, namely the Tucson International Airport and the county’s Mission Road Complex, which includes the county jail. That’s also why the Department of Interior recently awarded over half a million dollars to a multi-agency collaborative in southern Arizona to fight buffelgrass on our public lands, with an additional million and a half dollars anticipated over the next four years. The federal government clearly recognizes the risk buffelgrass poses to life, property, and our natural environment, but do Pima County residents themselves recognize this risk?
This was one of several questions that researchers asked local residents in a small survey conducted in 2010. The vast majority of the residents who responded to the survey recognized that buffelgrass poses a risk to the Sonoran Desert, but very few recognized that buffelgrass also poses a risk to their own lives and property. The most obvious threat, wildfires fueled by buffelgrass, may be greatest in the Catalina Foothills, where forest service lands meet resorts and subdivisions in the wildland-urban interface at Tucson’s edge. Consider the hundreds of homes lost to wildfire in California every year a reminder of a fate we should strive to avoid. But the risk of buffelgrass invasion comes in other forms as well, such as declining home values and adverse effects on the real-estate market as fires increase in frequency and buffelgrass degrades viewscapes. None of these risks were perceived by respondents.
Buffelgrass, (Cenchrus ciliaris), is native to parts of Africa and Asia. It found its way to Arizona in the 1940s when the Soil Conservation Service began testing its utility in erosion control. Over the next five decades, buffelgrass was planted in several locations in southern Arizona to control soil erosion on mine tailings and abandoned farmland and as cattle forage in the Santa Ritas. It inevitably escaped these intentional plantings and has spread widely throughout the region. But few places boast as much buffelgrass as the Catalina Foothills, where it is slowly replacing the saguaro-palo verde forests that blanket the lower slopes of the Catalina and Rincon Mountains. It’s spreading through the San Pedro River Valley to the east, and it’s abundant in Organ Pipe National Monument to the south. It can be found scattered throughout the protected areas to the west of Tucson, including Cabeza Prieta and Buenos Aires National Wildlife Refuges. To the north, it’s already common on streetsides, abandoned lots, and open space in Phoenix and spreading fast along Highways 60 and 87 into adjacent Tonto National Forest.
Intense fires carried by buffelgrass could transform large swaths of our desert into fire-prone grasslands overnight. Even without fire, buffelgrass competition for water, nutrients and space will compromise our saguaro-palo verde forests if buffelgrass goes unchecked. Research by Aaryn Olsson and colleagues in the Catalina Foothills found that the number of plant species in our native desertscrub communities declined by approximately 80% within 20 years of buffelgrass invasion. Although the abundance of adult saguaros remained unchanged after buffelgrass invasion, the number of young saguaros (less than 2 meters in height) was markedly lower in buffelgrass-invaded plots than uninvaded plots. We are witnessing a slow but steady decline in the saguaro population in areas where buffelgrass has grown thick, even without fire.
In the Tucson Mountains, prime buffelgrass habitat, buffelgrass is losing ground. tThanks to the efforts of Marilyn Hanson, Doug Siegel and a steadfast army of volunteer weedwackers you can still enjoy stunning and buffelgrass-free views over Gates Pass. The state of the Tucson Mountains is testament to what can be accomplished by a few dedicated volunteers with a long-term commitment to protecting our public lands.
The extent of the invasion in the Catalina Foothills has exceeded what even hundreds of volunteers could manage. But there’s hope. In 2015, Saguaro National Park led an effort to build the Southern Arizona Collaborative to address the growing threat of buffelgrass-fueled fires in southern Arizona. This collaborative was awarded over half a million dollars from the Department of Interior’s Wildland Fire Resilient Landscapes program, a new nationwide effort to restore and maintain landscapes across jurisdictions for fire resiliency. In 2015 the funding allowed Saguaro National Park and the Santa Catalina District of Coronado National Forest (CNF) to double the number of acres of buffelgrass treated, and in 2016, funding allowed over 160,000 acres across Buenos Aires National Wildlife Refuge, the Tohono O’odham Nation, and several districts of CNF to be mapped for buffelgrass. Funding in 2017 should allow the collaborative to more than triple the number of acres treated in 2015. Those with the responsibility of managing our public lands haven’t given up yet.
If we value our public lands, we have a responsibility to support the efforts of our land managers to fight buffelgrass. Not everyone has the time or strength to wield a shovel, but something everyone can do is reach out to their elected officials to let them know that buffelgrass is a major concern and advocate for a sustained effort to control buffelgrass along our roadsides and in our public lands. And perhaps the most effective form of support is a donation to the groups that are on the front lines. One of those groups is Sabino Stewards, which is part of the larger group Friends of Sabino Canyon. Since June 2014, volunteers with Sabino Stewards have worked over 1,600 hours to remove invasive plants, including buffelgrass, from over 330 acres in Sabino Canyon and the surrounding area. Other groups include Friends of Saguaro National Park and Friends of Ironwood Forest National Park. All are involved in the fight against buffelgrass. There is no more immediate threat to our public lands.
So how can you help? On January 21st, the Tucson community will hold its 10th annual Beat Back Buffelgrass Day. In recent years a few thousand volunteers have joined together on a winter Saturday to dig up buffelgrass from neighborhoods and parks in Tucson and Pima County. The saguaro is the symbol of our community, and every year people demonstrate that they are willing to sweat a little to protect our beloved cactus. If you haven’t come out for Beat Back Buffelgrass Day in the past, make this year your first. Sign up here.
Written by Kim Franklin, Ph.D., ASDM Conservation Research Scientist