National Park Service U.S. Department of the Interior Yellowstone National Park Invasive Vegetation Management Plan Environmental Assessment February 21, 2013 ii Invasive Vegetation Management Plan / Environmental Assessment Executive Summary Yellowstone National Park (YNP) has developed a plan to address terrestrial invasive nonnative plants parkwide. (As used here, the term “invasive nonnative plant” has a similar meaning as alien, exotic, or noxious plant or weed.) This Invasive Vegetation Management Plan and Environmental Assessment (EA) provides a comprehensive approach toward invasive vegetation management to preserve, protect, and restore the diversity, ecological integrity, and processes associated with native plant communities in the park. The purpose of the plan is to expand current invasive plant management efforts and implement a parkwide strategy to prevent the establishment and spread of invasive nonnative plant species and to restore, as needed, native plant communities in the park. The plan proposes to achieve these goals by accomplishing the following objectives: 1. Prevent the entry and establishment of new invasive plants 2. Control existing populations of invasive plants by eradicating them, reducing their abundance and density, and containing their spread 3. Restore native plant communities when they have been disrupted or replaced by invasive nonnative plant populations. This environmental assessment evaluates a No-Action Alternative and one action alternative: • Alternative A – The No-Action Alternative represents no change from the current direction as established under the 1986 Exotic Vegetation Management Plan (NPS 1986). • Alternative B – The Preferred Alternative proposes the implementation of an Integrated Weed Management (IWM) approach to invasive vegetation management in Yellowstone National Park. An IWM approach would incorporate a balanced strategy to successfully manage invasive plant populations and would include the following processes: a) prevention, b) identification, c) a combination of control methods based on best information, and d) evaluation toward effective adaptive management. This EA includes a review of the affected environment, methods to be used to manage invasive vegetation, and information on potential impacts on park resources from implementing the plan. Resources evaluated in detail in the EA include: soils; geothermal resources; wetlands and water resources; vegetation, especially rare plants; fish and wildlife, especially threatened, endangered, and special status species; archeological resources; cultural landscapes; health and human safety; visitor use and experience; and park operations. All other impact topics were dismissed because the potential effects of the alternatives under consideration to those resources would be negligible or minor. None of the alternatives under consideration are expected to result in major adverse impacts. Development of this plan included review of past efforts and public comments received during the public scoping process. Public scoping was conducted in March 2011 to assist with the development of this proposal. No major issues were raised related to the proposal. Comments received were mostly in support of the proposed plan. This EA has been prepared in compliance with the National Environmental Policy Act and other associated laws and regulations to provide the decision-making framework that (1) analyzes a reasonable range of alternatives to meet objectives of the proposal, (2) evaluates potential issues and impacts on the environment associated with the alternatives under consideration, and (3) identifies mitigation measures to lessen the degree or extent of these impacts. Executive Summary iii Public Comment Comments on this EA may be submitted through the NPS Planning, Environment and Public Comment (PEPC) website (http: //parkplanning.nps.gov/YELLInvVeg) or by mailing them to the following address: Invasive Vegetation Plan/EA, P.O. Box 168, Yellowstone National Park, WY, 82190. Comments may also be hand-delivered during normal business hours to the mailroom in the park’s administration building in Mammoth Hot Springs, Wyoming. Comments will not be accepted by fax, e-mail, or in any other way than those specified above. Bulk comments in any format (hard copy or electronic) submitted on behalf of others will not be accepted. Please be aware that all of the information provided in your entire comment—including your address, phone number, e-mail address, or other personal identifying information—may be made publicly available at any time. Although you can request to have your personal identifying information withheld from public review, the provisions of the Freedom of Information Act prevent us from guaranteeing that this will be possible. Comments will not be accepted by fax, e-mail, or in any other way than those specified above. Bulk comments in any format (hard copy or electronic) submitted on behalf of others will not be accepted. This EA will be on public review for 30 days. Comments must be received by midnight, March 22, 2013. iv Invasive Vegetation Management Plan / Environmental Assessment Table of Contents Purpose and Need .................................................................................... 1 Introduction .............................................................................................. 1 Background .............................................................................................. 1 Purpose and Need ..................................................................................... 3 Relationship to Other Plans and Policies ..................................................... 4 Scoping .................................................................................................... 5 Impact Topics Dismissed and Retained for Further Analysis ......................... 7 Alternatives ............................................................................................ 13 Alternative A: No Action—Current Management Practices ........................13 Alternative B: Integrated Weed Management Practices .............................18 Mitigation Measures Applicable to Both Alternatives .................................29 Alternatives Considered and Dismissed .....................................................31 Environmentally Preferred Alternative .......................................................31 Alternative Summaries .............................................................................32 Affected Environment ............................................................................ 37 Soil Resources ..........................................................................................37 Geothermal Resources .............................................................................37 Wetlands and Water Resources ................................................................38 Water Quality ..........................................................................................39 Vegetation including Rare Plant Species ....................................................40 Fish and Wildlife Species ..........................................................................43 Threatened, Endangered, and Special Status Wildlife ........................... ….45 Archeological Resources ...........................................................................49 Cultural Landscapes .................................................................................49 Health and Human Safety ........................................................................50 Visitor Use and Experience .......................................................................50 Park Operations .......................................................................................51 Environmental Consequences ............................................................... 53 Soil Resources ..........................................................................................55 Geothermal Resources .............................................................................60 Wetlands and Water Resources ................................................................64 Water Quality ..........................................................................................70 Vegetation including Rare Plants ..............................................................74 Fish and Wildlife Species ..........................................................................79 Threatened, Endangered, and Special Status Wildlife ................................83 Archeological Resources ...........................................................................90 Cultural Landscapes .................................................................................95 Health and Human Safety ......................................................................100 Visitor Use and Experience .....................................................................104 Park Operations .....................................................................................109 Consultation and Coordination ........................................................... 113 Internal Scoping .....................................................................................113 External Scoping ....................................................................................113 Agency Consultation ..............................................................................113