At 7:15 a.m. on a Saturday in late October, the only people out and about are dog-walkers, mailmen and people on their morning drives to retail jobs.
But also hard at work in a South Tucson wash is a group of about 50 people armed with shovels and digging bars. The army of volunteers, working in teams of three, are spending the morning digging up 65 trash bags' worth of an invasive grass species that many think has been taking over Pima County.
As the county's war on buffelgrass continues, groups of volunteers have begun sprouting in neighborhoods throughout Tucson and have taken to the washes in an effort to control a species that has fueled fires and choked out plants native to the area. But even as efforts to control buffelgrass increase, residents of Southern Arizona are learning to live with it.
The buffelgrass pull on this particular Saturday is in a section of Airport Wash, just north of Sunnyside Neighborhood Peace Garden, near South 12th Avenue and Drexel Road.
The effort is being led by Erin Willett, the buffelgrass outreach coordinator for Tucson Clean and Beautiful, a nonprofit that hosts recycling and cleanup projects around the city. The day's volunteers include veterans of the local buffelgrass-pulling scene, Tucson residents interested in community engagement and dozens of members of the pledge class of the Pi Kappa Alpha fraternity chapter at the UA.
Because there isn't much funding for buffelgrass pulls like this one, Willett said they're almost entirely done with volunteers.
"There really isn't a funding mechanism at this point," she said. "So it's actually pretty amazing that there are so many dedicated volunteers because it's actually kind of hard work."
After grabbing tools and gloves, the groups go to work.
The invasion and the response
Lindy Brigham is executive director of the Southern Arizona Buffelgrass Coordination Center, established in December 2008 as a clearinghouse for dealing with a plant that crosses jurisdictional boundaries. Six months later, Brigham was appointed to her current position.
Buffelgrass, Brigham said, arrived here in the 1930s, when the African plant was brought to Texas to supplement the state's cattle industry and then was planted in Arizona for erosion control. The problems with it intensified half a century later when there were massive plantings by mines, agricultural interests and the city of Tucson.
Brigham's aim is to spread community awareness about buffelgrass, educating volunteers on what they can do to keep it from spreading. Her center provides resources and information and also organizes events like Beat Back Buffelgrass Day, which is scheduled to occur again on Saturday, Jan. 25.
Efforts over the past several years have met with some success. "We're actually getting a handle on specific areas," she said. "This is such a wide-scale problem that obviously there's still going to be buffelgrass all over the place. But places where we've identified it to be really important to remove, there's been a concerted effort."
The science behind the species
If any one person is Tucson's resident buffelgrass expert, it might be Travis Bean.
From the balcony of his office, Bean, a doctoral candidate in the UA's renewable natural resources studies program, can spot populations of the plant on the sides of the Catalina Mountains. Bean has nearly a decade of experience researching the plant, beginning in 2004 with the explosion of a Kinder Morgan Energy Services gasoline pipeline in a neighborhood north of Tumamoc Hill.
In addition to the cleanup cost, the corporation also agreed to provide compensation to nearby entities affected by the disturbance. Among the recipients was the UA's Desert Laboratory, a century-old environmental studies site on Tumamoc Hill. The explosion, Bean said, rid the hill of much of its native grass species. But in an area where seeding has been ineffective thanks to the dry climate, efforts at plant restoration would have been a waste of the compensation funds.
So the Desert Laboratory instead used the money to hire Bean as a weed scientist who would spearhead the mitigation of buffelgrass, which had infested the eastern, western and southern slopes of Tumamoc Hill. But soon after starting the project, Bean said he realized his efforts alone wouldn't be enough.
"One of the things that quickly became apparent to me and people that I was working with was that we couldn't really make a dent in it without convincing our neighbors to do something," Bean said. "So my job quickly became not only trying to get buffelgrass under control on Tumamoc, but a regional outreach type of position where we tried to get everybody else involved."
Bean's focus has since shifted from outreach coordination back to the science behind the plant—specifically, learning when buffelgrass is most vulnerable during its germination state and changing the solution used to spray it. The idea, Bean said, is to find a way to kill substantial amounts of buffelgrass with smaller amounts of herbicide, and to find a herbicide that works when the grass is dormant.
Currently, the only way to treat populations of buffelgrass is to apply glyphosate—a common herbicide and the only one known to kill mature buffelgrass plants—to the grass when it turns its greenest during the summer monsoon season.
"I'm trying to figure out if there's something that we could apply during the dormant season so we don't have to send crews out during that really unpredictable one- or two-week window during the worst part of the year when it's 110 degrees out," Bean said.
The plant's future
Bean fears the fight to completely eradicate the plant that is choking off Southern Arizona's native vegetation has come too late. Although he hasn't given up hope, Bean doesn't mince words about how deeply rooted buffelgrass has become. His concern, he said, isn't whether the removal methods are effective, but whether they can keep up with the spread of the plant.
"It's not that these methods don't work, it's that the grass is spreading too fast and we've started too late with too few resources," he said. There were an estimated 10,000 acres covered with buffelgrass in Pima County in 2009, Bean said, and the amount had more than doubled by 2012. Brigham, the Southern Arizona Buffelgrass Coordination Center director, agreed, adding that the next best option would be to focus on certain areas.
"We never say that we're going to eradicate buffelgrass from this area—we can't," Brigham said. "What we can do is manage the areas that are most critical to us."