With the increase in moisture brought on by monsoon rains, conditions are optimal for seasonal restoration work to resume in Saguaro National Park. The park, along with other city, county, state and other federal agencies, will be using ground-based field crews to apply herbicide on buffelgrass and improve conditions for native plants.
Buffelgrass is an aggressive, non-native grass that competes with native plants such as saguaros and palo verdes, and many other native Sonoran Desert plants. Buffelgrass also carries hot and intense fires in an ecosystem that is not adapted to fire. If buffelgrass continues to spread, it will be a serious threat to biological conservation efforts and buffelgrass fires may also become a major threat to public safety and property. Buffelgrass is listed as a noxious weed by the state of Arizona.
There are two main ways to effectively control buffelgrass. If more than half of the plant is green, herbicides with the active ingredient glyphosate are used. This herbicide is absorbed by the green, actively growing leaves. If the grass is less than 50 percent green, hand removal is the best method. However, this is a slow, labor-intensive process, and pulling alone cannot keep up with rapidly spreading buffelgrass.
Park employees and volunteers, including local residents and groups have been instrumental in helping to manually remove buffelgrass in the park. Tucson Clean and Beautiful, Sonoran Desert Weed Wackers, and Southern Arizona Buffelgrass Coordination Center are just a few of the many groups working to control buffelgrass in the greater Tucson community.
The park plans to treat approximately 50 miles of roadway and 450 acres of park land in both the Tucson Mountains and Rincon Mountains during the next two to three months beginning in mid-July. No public closures are anticipated. An area is safe to enter as soon as the herbicide dries which is within 15 minutes after application. A blue dye will be mixed with the spray to mark plants that have been treated. This treatment plan was approved for use in an environmental assessment, which can be viewed at www.nps.gov/sagu/parkmgmt/restoration-plan.htm
This approved plan also includes the use of helicopters to spray herbicide on steep, remote patches of invasive, non-native plants, specifically buffelgrass. Aerial spraying is planned for later this summer. Additional information will be released as it becomes available, specifying locations, dates and any potential closures.
For additional information, including a map of areas to be treated by ground crews, please visit this website: http://www.nps.gov/sagu/naturescience/invasive-plants.htm.