NPS photo/Bethany Hontz
Whether they arrived by wind or water, bird or boots, or were planted intentionally for soil conservation or forage, invasive plants are a threat in
Photo courtesy of East Valley Tribune
Buffelgrass: Wanted Dead and Gone
Saguaro National Park’s iconic species, the saguaro cacti, is severely threatened by the invasion of buffelgrass (Pennisetum ciliare syn. Cenchrus cilaris), a perennial bunchgrass from Africa. In the last decade, buffelgrass has rapidly spread across southern
Native, Non-native, and Invasive Plants…What's the Difference?
Native plants evolved as part of the ecosystem and have been part of our landscape since before the arrival of Europeans.They have adapted through natural selection to the soil, climate, and other plants and animals of the ecosystem.Non-native plants, also known as "exotics" or "aliens," are recent arrivals from other ecosystems.The diseases, pests, and predators that keep most species in check may not exist for them in our ecosystem, creating a potential for them to become invasive.Not all non-natives are invasive; non-native species such as roses, petunias, and tomatoes, present no threat to our park.Non-native invasive plants spread aggressively and out-compete the native plants, disturbing the natural balance of the ecosystem. Although a few native plants, such as desert broom, may be considered invasive, management efforts at
Learn more about our worst invasive plants:
-Buffelgrass (Pennisetum ciliare syn. Cenchrus cilaris)
Here's a complete list of established, eradicated, and early detection non-native species found in the park.
Management Strategies at Saguaro National Park
Invasive plant management is not a one-size-fits-all type of effort. For our efforts to succeed, we implement species-specific management strategies.
We implement the most appropriate control technique for each species and site, considering the extent of the invasion and the threat it represents. We ensure the control is environmentally safe and supported by research.
The methods we use are chiefly manual removal and chemical control. You may have seen teams of hardy buffelgrass removal volunteers, with gloves and tools, digging out the plants. Park Service staff also apply an herbicide containing glyphosate during the growing season, to plants that are over 50% green.
Fire control is successfully used in other National Parks to control some of the same invasive plants. However, here at Saguaro National Park, where the native plants are not fire-adapted but the non-natives are, fire is less appropriate as a method of control. Biological controls, introducing another exotic species to control the invasive plant, such as goats to eat the grasses or insects to destroy the seeds, are not in current use.
There are opportunities throughout the year to help with buffelgrass management at Saguaro National Park, as well as other areas in and around Tucson. Activities include mapping buffelgrass infestations, participating in the Weed Free Trails program, joining monthly buffelgrass pulls (September-May), as well as education and outreach events. See our Schedule of Special Events or contact the invasives species coordinatior at e-mail us.
-Want to help? Find out how you can help at home and in the park
-Buffelgrass look-alikes: learn about native grasses commonly mistaken for buffelgrass