Last updated: August 14, 2024
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Invasive Buffelgrass Poses Significant Threat to Sonoran Desert Habitats
Saguaro National Park was named after the iconic Saguaro cactus which is native to the Sonoran Desert and a symbol of the American Southwest. Visitors come to Saguaro National Park to experience the unique wildlife and culture the park has to offer. The Sonoran Desert is home to many native species like the Sonoran Desert tortoise, Gila monster, and javalina. Saguaro National Park also features dwellings, pottery shards and pictographs that hold stories of the Indigenous tribes that once inhabited the desert.
Buffelgrass is a non-native perennial bunch grass that was brought from Africa and introduced to the Tuscon area in the late 1800s. It was used for erosion control and cattle feed but, it has since become an invasive species. “Buffelgrass has invaded sections of the park as well as other federally managed lands.” Frankie Foley, NPS biologist said.
The main threat buffelgrass poses to Sonoran Desert ecosystems is the risk of wildfire. “Buffelgrass fires can burn at over 1000-degrees Fahrenheit,” Foley said. “That can have a detrimental impact on the very slow growing cacti species and wildlife that are special to Saguaro National Park.”
NPS Photo
According to Foley, the Saguaro cacti is especially vulnerable to the threats of buffelgrass. This species did not evolve with fire and does not respond well to being burned. Buffelgrass is the primary threat to the health of Saguaro National Park’s native vegetation. The Sonoran Desert tortoise is also particularly vulnerable to threats of wildfire caused by a buffelgrass invasion. Habitat destruction is among the primary threats to the Sonoran Desert tortoise.
Fortunately, Saguaro National Park has yet to experience a wildfire due to buffelgrass invasion, and park staff are proactively mitigating the risk with the help of Bipartisan Infrastructure Law funds. Boot brush stations are being installed at every trailhead and entrance to the park. Boot brush stations are used to reduce the spreading of invasive seeds by rubbing shoes against bristles before and after using a trailhead. “Without those, people very easily could take seeds that are on their boots into the backcountry and increase chances of spreading those invasive plant seeds,” Foley said.
The most efficient and effective way of addressing buffelgrass invasion is by spraying herbicide during buffelgrass green-up; however, buffelgrass is challenging because of the unpredictable spotty nature of precipitation patterns in the park. Predicting when buffelgrass will be green enough to spray is a crucial factor in reducing the invasive species. “If less than half of the vegetative parts above ground are not green, the plant will not be receptive to herbicide applications,” Foley said.
When the buffelgrass is not green enough to spray, they must be removed by hand. Volunteers are critical in the manual labor of digging out buffelgrass plants. “The Tuscon community understands the threat of buffelgrass and are generous with their free time in assisting to remove it from the Park,” Foley said.
Bipartisan infrastructure Law funds are allocated to support the equipment and staffing needed for this project. “Herbicide application at Saguaro National Park is sprayed from both backpack sprayers and helicopters,” Foley said. “Funding has been obligated for contractors to spray buffelgrass in remote and rugged parts of the park with helicopters. We simply could not spray those areas on foot.” Funds were also used for NPS personnel costs and to support financial agreements to continue working with youth corps.
Ancestral Lands is one of the youth conservation corps local to Saguaro National Park. “We partner with Ancestral Lands to bring native youth to the park to help with some of the land management work that we do,” Foley said.
The Bipartisan Infrastructure Law funds are helping to not only advance the National Park Service mission by protecting and preserving natural and cultural resources, but also by establishing partnerships and providing for the professional advancement of youth. Support such as this ensure Saguaro National Park remains a suitable habitat for native plant, animals, and people alike.