Invasive exotic plant monitoring in Zion National Park: 2015 field season
Karinen S and Perkins D. 2016. Invasive exotic plant monitoring in Zion National Park: 2015 field season. Natural Resource Report. NPS/NCPN/NRR—2016/1258. National Park Service. Fort Collins, Colorado
Invasive exotic plant (IEP) species are a significant threat to natural ecosystem integrity and biodiversity, and controlling them is a high priority for the National Park Service. The Northern Colorado Plateau Network (NCPN) selected the early detection of IEPs as one of 10 monitoring protocols to be implemented as part of its long-term monitoring program. During surveys conducted on June 17–24, 2015, NCPN staff detected 108 patches of 14 IEP species (eight of which were priority species) along 155.0 kilometers of monitoring routes and transects at Zion National Park. Scotch thistle (Onopordum acanthium), little bur-clover (Medicago minima), Bermudagrass (Cynodon dactylon), Johnsongrass (Sorghum halepense), and Siberian elm (Ulmus pumila) were the most commonly detected priority invasive plants. The highest numbers of priority infestations were found at the Watchman Campground and Visitor Center area (4.55 infestations/km), Watchman Housing Area (2.18/km), South Campground and Nature Center (1.94/km), Oak Creek and Administrative area (1.79/km), and Visitor Center Trails (Archaeology, Museum, Pa’rus, and Watchman) (1.18/ km). Roads generally had higher patch densities than trails. Several trails were free of priority IEP patches. IEPs were found on 184 transects (62%), with an average of 0.66 IEP species detected per plot. However, almost all of these detections were cheatgrass (Bromus tectorum). Cheatgrass was widespread—present in 62% of transects and with an estimated cover of 0.77% across all transects sampled. Cheatgrass cover was as high as 2.04% along the Zion Scenic Drive and 1.92% along the Sand Bench Trail. In areas that were sampled in 2012–2013 and 2015, declines in Johnsongrass, bulbous bluegrass (Poa bulbosa), and Siberian elm were observed. These declines were seen along the Kolob Terrace Road and in the Main Canyon. A more complete analysis will be completed after the 2016 field season completes the second full rotation of routes at Zion National Park.
- Type
- Published Report
- Authors
- Karinen, Sarah; Perkins, Dustin
- Date of Issue
- 2016-08
- Publisher
- National Park Service
- Units
- NCPN , NRSS , ZION
- Keywords
- Exotic Species, Exotic/Invasive Species - Plants, Invasive Species, Monitoring, NCPN Invasive Plants Monitoring, Plant Studies