Before and after treatment, buffelgrass is monitored to ensure the effectiveness of the aerial herbicide application. Key plant species, such as saguaros, are also surveyed before and after treatments to assess the potential impacts to native plants. Results from these studies, which are still being analyzed, will inform future managements actions.
The Plan to Fight Buffelgrass and Restore Native Habitat
Last year, Saguaro National Park completed a Restoration Plan and Environmental Assessment (RPEA) that describes management actions proposed to restore native vegetation and mitigate negative impacts to park lands from damage caused by wildfire, floods,invasive species, or other large-scale changes to the environment. The RPEA, which was available for public review and comment for 30 days, included descriptions of the proposed alternatives, and identified and compared their potential environmental impacts. The preferred alternative includes all of the restoration techniques the park had been using to date, and allows for aerial (helicopter) delivery of restoration treatments to sites that are not accessible by ground crews. The National Park Service approved the RPEA with a Finding of No Significant Impact (FONSI) that took the assessment and public comments into account, and accepted the preferred alternative.
Subsequently, over 250 acres of buffelgrass infested park lands were aerially treated with herbicide between August 18-24, 2014. There was evidence of die back within a few days of treatment, and four months late it was clear that the treatment had been effective (see photos below). Per the Plan, monitoring of both buffelgrass and native plants in treated areas will inform future park decisions regarding future aerial treatments. Some areas with a large seed bank will require several years of retreatment to kill new buffelgrass plants, before the native vegetation can recover.