Fall 2002 Report for Tamarisk Eradication and Restoration of 63 Tributaries in Grand Canyon National Park

Makarick, Lori

Tributaries and side canyons of the Colorado River, and seeps and springs in Grand Canyon National Park (GCNP), are among the most pristine watersheds and riparian habitat remaining in the coterminous United States. These riparian systems deserve a high level of protection from nonnative plant invasion. The encroachment of tamarisk into these tributaries poses a significant threat to the integrity of the natural ecosystems. GCNP is committed to the preservation of native plant communities and native ecosystems. National Park Service (NPS) Management Policies require park managers "to maintain all the components and processes of naturally evolving park ecosystems, including the natural abundance, diversity, and genetic and ecological integrity of the plant and animal species native to those ecosystems" (NPS 200 1b). Park managers are directed to give high priority to the control and management of exotic species that can be easily managed and have substantial impacts on the Park's resources (NPS 1985, NPS 2001b). The primary objectives of this portion of the overall project are to remove tamarisk from 63 tributaries of the Colorado River in Grand Canyon National Park, and to monitor the success of the tamarisk removal through pre- and post-removal plant monitoring. This project will significantly reduce tamarisk clistribution within the treated areas, and allow native vegetation to reestablish without exotic plant competition. Prior to initiation of the project, extensive public scoping was completed and an Environmental Assessment / Assessment of Effect (EAI AEF) was prepared. Under the new Director's Orders on Compliance (NPS 2001a), cumulative effects of multiple projects were considered, and talnarisk removal in all of the park's tributaries was included in the document and analyzed. After review of the public comments, GCNP issued a Finding of No Significant Impact (FONSI) for the project in June 2002. Upon completion of the FONSI, GCNP restoration biologist Lori Makarick worked with the Grand Canyon Wildlands Council (GCWC) to revise the Tamarisk Eradication Plan, budget and contract for this project, and then began to plan the logistics for the fall 2002 river trips. Two eradication trips were conducted in the fall of 2002. On these trips, tamarisk eradication was initiated, and work was completed in 45 of the 63 project areas. Over 15,000 tamarisk trees were removed from the project areas. The fall trips were extrelnely successful, and the project is now well underway. This report will detail all of the work completed this fall, and will layout the remaining work that will be completed in the fall of 2003, and the spring of 2004.