Restoring Native Vegetation on Ungulate Winter Range in and near Yellowstone National Park, U.S.A.
- Characterize site
- Identify obstacles to success (driving forces)
- Set sustainable goals and success criteria
- Prepare site
- Stabilize site from erosion (soil repair)
- Select species and species source
- Identify and implement seeding techniques
- Manage site to enhance success
- Temporary wildlife exclusion
- Weed control
- Monitor success
- Refine strategies to achieve goals
Hektner, M.M.1, A.L. Burton2, M.L. Pokorny3, R.A. Renkin1, and P.J. White1
1 National Park Service, 2 USDA Forest Service, 3 Montana State University
Case Study: Restoration Strategy for Yellowstone National Park’s North Entrance area
The area immediately north of Yellowstone National Park, known as the Gardiner Basin, was deemed essential for elk and pronghorn winter range and acquired for the park in the 1920s and 1930s. The U.S. Forest Service (Gallatin National Forest) similarly acquired adjacent lands in the Gardiner Basin during the 1990s. Due to previous agricultural land use, semi-arid conditions, altered hydrologic regimes and soil conditions, and increased exotic weeds, these acquired lands support relatively low amounts and quality of forage for wildlife.
Recent unsuccessful attempts at restoration demonstrated that additional expertise from diverse disciplines was needed to effectively restore the degraded ecosystem to native vegetation and provide higher quality habitat for wintering ungulates. The National Park Service, Gallatin National Forest, and the Center for Invasive Plant Management at Montana State University convened a facilitated workshop in April 2005 with state, federal, academic, and practicing restoration and reclamation specialists to develop feasible, ecologically-based restoration and management strategies for these former agricultural lands.
During the workshop, invited restorationists were oriented to the sites, identified driving forces to address during the restoration process, listed and described values to be achieved through restoration and the desired vegetation condition necessary to realize those values, created restoration strategies, and assessed the feasibility, cost and timing necessary to implement the strategies.
- The group identified guiding principles to oversee the restoration project:
- Begin each restoration project by developing a site characterization including soil analysis and a conceptual model. This should include soil chemistry analysis, characterization of soil physical structure, and soil water infiltration. All of these will help determine if soil chemical and physical properties need to be repaired during the implementation phase.
- 2. Develop clear, specific goals with clearly defined objectives. They should identify desired abiotic and primary process functions such as the ability for water and nutrients to be captured and incorporated into the soil. They should also specify the desired native plant association, including composition and structure, spatial patterns of vegetation where appropriate, and function of the site including use as wildlife habitat, scenic values, aesthetic values, watershed values, and other important functions. Restoration objectives should be realistic in spatial and temporal scales. Performance goals/success criteria will help measure the success of restoration effects and/or guide adaptive management.
- 3. Use the best science and technology to tackle these restoration projects.
- Use ecological principles to guide the restoration strategies. By addressing the ecology of the system and the causes of degradation, restoration techniques may develop sustainable, functional ecosystems that fit and blend into the landscape over a period of time. Use techniques, equipment and materials to address the basic causes of degradation.
- 4. Use a stepwise approach to move sites through stages of restoration. Basic ecological processes (nutrient, water, energy cycles, succession) have been disrupted. Successful restoration will depend on repairing these functions so the sites can become self-sustaining. A succession staircase of several steps (see upper right) may be necessary to achieve the restoration goals, rather than a one-step approach from the present highly degraded condition to a fully functioning native plant association.
- Driving Forces
- Sodium flocculated surface soil and possible salt accumulation due to past land uses (irrigated agricultural fields, now dominated by annual and perennial exotic weeds)
- Semi-arid climate (less than 254 mm precipitation/year)
- Soil (wind) erosion
- Heavy winter ungulate use
- Site Restoration Goal: Restore functioning water, soil, and energy cycles; soil properties; and a sustainable native shrub-grassland plant association similar to the site potential.
- Restoration Strategy
- 1. Characterize soils: conduct soil analysis to assess the type, amount and fine-scale location of soil amendments needed
- Determine where to sample: transects by gradient, changes in soil surface & vegetation, include reference sites
- Sample at soil depths of 0-6, 6-12, 12-24 inches
- Analyze soils for pH, ESP, organic matter, presence/depth of clay pan, % particle size separation, Na, salt accumulation
- 2. Repair soil properties. If soils are sodic, apply gypsum to reduce ESP to <10
- 3. Rip soil to 1ft depth, at 1ft spacing. Rip soils in two perpendicular passes to avoid row visual effects. Ripping will incorporate gypsum, reduce soil compaction, and decrease water and nutrient movement off-site.
- 4. Apply polyacrylamide if necessary to control erosion.
- 5. Fence the restoration and reference sites to decrease grazing pressure while plants establish.
- 6. Use a no-till drill to plant a preparatory cover crop in ripped area to hold the soil and decrease weed competition prior to planting desired native species.
- 7. Determine if local ecotypes and seed increase or cultivars will be used for the revegetation.
- 8. Spray preparatory crop at milk stage with Roundup® to terminate crop and to leave stubble to capture moisture and soil and add to organic matter. Spot treat weeds through rest of growing season.
- 9. Conduct fall dormant planting into the preparatory crop stubble after October 15 using a no-till drill and native seed mixture. Fall seeding has been found to be the most successful in this region. By seeding with two perpendicular passes, undesired visual effects of drill rows can be minimized.
- 10. Broadcast seed shrubs and small-seed species at the same time as drill seeding the other species by putting these species in a separate seed box on the drill and unhooking the tubes so the seed falls freely on the ground. Broadcasting behind the drill can also reduce the drill row effect.
- 11. Do NOT irrigate. Establish plants under natural conditions. The plants that do become established will have a better chance of long-term survival.
- Monitoring and Management Strategy
- Continue to mow and / or spot spray invasive species while desired species establish.
- Develop monitoring program and transects.
- Monitoring will continue indefinitely on the site.
- Assess the wildlife and restoration interactions.
- Continue to address ecological processes: keep addressing causes of problems and not just symptoms
- Remain patient
- Identify alternatives at every step
- Quantify the
- Compliance needs
Funding for the workshop was provided by the Yellowstone Park Foundation and Canon U.S.A., the Rocky Mountains-Cooperative Ecosystem Studies Unit and the Greater Yellowstone Coordinating Committee.
Mr. Jerry Benson, BFI Native Seeds
Dr. Gregory Eckert, USDI National Park Service
Mr. Reginald Hoff, Big Sky Coal Company
Mr. Larry Holzworth, USDA Natural Resource Conservation Service
Dr. James Jacobs, Montana State University
Mr. Dennis Neuman, Montana State University
Dr. Roger Rosentreter, USDI Bureau of Land Management
Dr. Jerry Schuman, USDA Agricultural Research Station
Dr. Steven Whisenant, Texas A&M University
Dr. Cathy Zabinski, Montana State University
- Workshop objectives were to:
- Formulate a directional, coordinated plan for the restoration and long- term management of approximately 500 hectares of former agricultural fields with Yellowstone National Park and Gallatin National Forest.
- Develop an action plan to implement ecologically-based and sustainable practices for restoration of disturbed lands in a multi-use, semi-desert ecosystem with high levels of use by native ungulates.
- Provide information on the feasibility, methodologies, timeframes and costs of alternative restoration strategies.
1930s farming operation in the North Entrance area.
Uncultivated shrub-dominated natural community.
Degraded conditions and soil erosion near Yellowstone Park’s North Entrance.