Invasive exotic plant monitoring in Capitol Reef National Park: 2016 field season

Perkins, Dustin

Invasive exotic plant (IEP) species are a significant threat to natural ecosystem integrity and biodiversity, and controlling IEPs is a high priority for the National Park Service. The Northern Colorado Plateau Network (NCPN) selected the early detection of IEPs as one of 11 monitoring protocols to be implemented as part of its long-term monitoring program. In conjunction with park staff, the NCPN created a target list of priority IEPs for early detection at Capitol Reef National Park. During surveys conducted on June 14–18, 2016, NCPN staff detected 638 patches of seven priority IEP species along 60.7 kilometers on the Highway 24 (531 patches) and Pleasant Creek (107 patches) monitoring routes, and three IEP species in transects. The species detected most frequently was tamarisk (Tamarix spp., 369 patches), followed by Russian olive (Elaeagnus angustifolia, 82 patches), quackgrass (Elymus repens, 54 patches), field bindweed (Convolvulus arvensis, 17 patches), asparagus (Asparagus officinalis, 5 patches), burdock (Arctium minus, 2 patches), and tree-of-heaven (Ailanthus altissima, 2 patches). Jointed goatgrass (Aegilops cylindrica, not a priority species), burdock, and quackgrass were all recorded for the first time along the Highway 24 route, while asparagus was recorded for the first time along Pleasant Creek. This was the first record of jointed goatgrass in the park. Two small infestations of tree-of-heaven were present after being absent along Highway 24 in 2013. IEPs were found on 56% and 20% of transects along the Highway 24 and Pleasant Creek routes, respectively. Cheatgrass (Bromus tectorum, only recorded in transects) had the highest percent cover of all species, at 2.77 and 1.70 percent cover at Highway 24 and Pleasant Creek. There was also high cover for tamarisk (1.37%) and Russian thistle (1.24%) at Highway 24. The recently completed (2016) monitoring rotation found large increases in tamarisk and Russian olive along these two routes compared to the earlier time periods of 2003–2005, 2009–2012, and 2013–2015. More Russian-olive patches were recorded along these routes in 2016 than in any other sample period. There was also a larger overall number of patches and a larger percentage of large patches, indicating that existing infestations are expanding and growing. The NCPN will skip monitoring in 2017 before returning in 2018 to complete the Cathedral Valley, Scenic Drive, and Oak Creek routes. Those routes will complete the third monitoring rotation.

Invasive exotic plant monitoring in Capitol Reef National Park: 2016 field season

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