Figure 1. Invasive tamarisk vegetation dominates much of the shore of the Green and Colorado Rivers in Canyonlands National Park. Human dimensions research sought to understand visitors’ knowledge of tamarisk, support for its removal, norms and preferences for control methods, and the need for more interpretation of invasive species control and ecological restoration.
During a park experience, what do visitors think about ecological resource management practices used to control invasive species? This is a question we sought to answer related to tamarisk control along river corridors in Canyonlands National Park in Utah.
Tamarisk (Tamarix spp.) is a prevalent invasive alien plant genus found commonly on the waterways of the Colorado Plateau in the western United States. To survive dry desert climates, tamarisk grows close to water sources and forms thick groves along riverine corridors such as the Colorado and Green rivers (fig. 1, above). Some public land management agencies, such as the National Park Service (NPS) and the Bureau of Land Management (BLM), have employed numerous efforts and resources to control invasive plant species and restore areas to a more natural state. Executive Order 13112 mandates federal agencies, where practicable and permitted by law, to take actions including preventing the introduction of invasive species, detecting and responding rapidly to and controlling populations of such species in a cost-effective and environmentally sound manner, and providing for restoration of native species and habitat conditions in ecosystems that have been invaded (Williams 2005). Methods used to control tamarisk have included manual removal (pulling trees and cutting stumps), mechanical (mulching trees), chemical control (foliar herbicide application), biological control (the release of the tamarisk leaf beetle, Diorhabda elongate), and prescribed fire (Belote et al. 2010; Harms and Hiebert 2006).
While diverse methods are used to control tamarisk, public natural resource management decisions may need to consider policy and social factors tied to visitor experiences. The National Park Service (NPS) mission, for example, strives to preserve park resources and values for visitor enjoyment (USDOI 2006). Studies have acknowledged that invasive species’ presence along river corridors could alter opportunities for shade, shore access, safety elements, access to cultural sites, scenic viewing, and opportunities for viewing wildlife during river-based recreation experiences (Belote et al. 2010). Few studies have addressed the human dimensions of managing invasive species, such as stakeholder knowledge of ecological aspects of public lands, support for or opposition to invasive species control methods, and need for interpretation regarding these areas of public land management (Hultine et al. 2010). More research is also needed regarding human dimensions of invasive species management along river corridors closely tied to communities dependent on recreation and tourism uses of the river resource. This article examines river users’ knowledge of tamarisk, desire and reasons for removal, acceptability of control methods, potential for disagreement about acceptable control methods, implications for visitor experience setting and soundscape, and preferences for additional tamarisk management interpretation and education along the Green and Colorado river corridors.
While diverse methods are used to control tamarisk, public natural resource management decisions may need to consider policy and social factors tied to visitor experiences.
Ceurvorst, R. L., and E. Clay Allred. 2013. An exploration of the human dimensions of riparian tamarisk control in Canyonlands National Park, Utah. Park Science 30(1):27–35.
Available at http://www.nature.nps.gov/ParkScience/archive/PDF/Article_PDFs/ParkScience30(1)Summer2013_27-35_CeurvorstAllred_3649.pdf.