Garvin Heights Restoration

A collaboration between Winona State University, City of Winona, Conservation Corps of Minnesota and Iowa, Diversity Landworks LLC, and The Landscape Arboretum at Winona State University, with funding from Minnesota's Environment and Natural Resources Trust Fund.

About the Project

With three years of funding from Minnesota’s Environment and Natural Resources Trust Fund, we will work to restore the 40-acre Garvin Heights Natural Area. Garvin Heights is a public park located on a 500-foot-high bluff overlooking the City of Winona. The park includes lands owned by the City and by Winona State University. An estimated 40,000 to 50,000 people visit the park each year.

The Garvin Heights Natural Area project site is located in the central part of the Blufflands Subsection of the Paleozoic Plateau. The Blufflands has the most Species in Greatest Conservation Need (SGCN) of any subsection in Minnesota, including 82 species that are federal or state endangered, threatened, or of special concern. Oak savannas and prairies are key habitats for SGCN within the Blufflands, but most (97% and 99%, respectively) have been lost since the 1890s. The proposed project will restore and enhance bur oak savannas and dry bluff prairies, protect additional cliff and bluff habitats, and enhance pollinator populations by managing invasive plants and replanting with native species. The high-visibility project site will showcase invasive species management and habitat restoration to a large public audience, inventory/monitor for SGCN, encourage public participation in the restoration, and provide additional and continuing opportunities for landowner education in invasive plant management and habitat restoration.
The restoration project will be undertaken as three inter-related activities:

Activity 1: Habitat delineation via GPS/GIS, pre- and post-restoration inventory and monitoring of invasive, native, and rare/indicator species, and educational signage development and placement

Dry bluff prairies, bur oak savannas, and oak-basswood woodlands will be delineated and mapped (GPS/GIS) throughout the project site. The project site includes three separate dry bluff prairies, two separate bur oak savannas, and oak-basswood forests on east-facing, west-facing, and north-facing slopes. Habitats will be delineated and mapped to document the locations and acreages of each habitat type within the project site, producing a digital GIS database that will be used to guide the current project and future management efforts.

All habitats will be monitored to inventory existing plant communities prior to and after restoration and to determine the abundance of rare, threatened, and/or indicator species (plants, birds, pollinators), to assess the success of the restoration. Local herbarium and county biological survey records also will be used to document past flora and fauna within the project site. Plot, transect, and random stratified sampling will be used to assess plant communities, point counts will be used to document breeding bird populations, and a combination of active netting, light traps, and pit traps will be employed to survey the abundances or pollinators and other invertebrates.

New and expanded educational signage will be developed and installed within each habitat. Existing signage is limited to historical photographs and general information and photographs describing invasive species, prairies, and savannas, all in a single location. New, habitat-specific signage will be developed and placed in each habitat type to highlight the restoration process and flora and fauna within the various habitats. Signage will emphasize the roles of the CC of MN and goat grazing in the restoration process. Temporary signage will be developed and placed during various stages of the project to keep the general public informed of ongoing activities.

Activity 2: Invasive plant removal by goats and CC of MN, and reseeding/replanting of 40 acres of bluff prairies, savannas, and bordering woodlands

Buckthorn, honeysuckle, oriental bittersweet, and red cedar will be removed from dry bluff prairies, bur oak savannas, and oak-basswood forests by grazing goats, the Conservation Corps of Minnesota, and community volunteers. CC of MN will begin by removing large buckthorn from oak savanna habitat and conducting prescribed burns on savanna and prairie sites. Some non-buckthorn trees also may be thinned from savannas to restore the native, open condition. Goat grazing (twice per year, each year) will remove woody vegetation (small or re-sprouted buckthorn and honeysuckle) on savanna habitats and severely invaded sections of prairie. CC of MN personnel and volunteers will remove buckthorn, honeysuckle, bittersweet, and red cedar from sensitive, less-invaded bluff prairie and forest habitats.

Prairies and savannas will be restored by seeding and planting with native forbs (emphasizing flowering species to enhance pollinator populations) and grasses, and savannas and forests will be restored by planting bur oak saplings and other tree species as needed to enhance natural reproduction. Appropriate seed mixes for southeastern Minnesota dry bluff prairie and bur oak savannah will be prepared by a regional seed source company. Inter-seeding of prairie and savanna habitats will occur during fall, winter (over snow), and/or spring to maximize effectiveness. Young trees will be hand-planted on savanna and forest habitats as needed to restore native species that are absent, low in abundance, or lacking in successful recent recruitment.

Activity 3: Invasive management workshop development and initial delivery to regional landowners, interested public

One-day and two-day, hands-on workshops will be developed for and presented to regional landowners and other stakeholders to explain and demonstrate the process and methodology of invasive plant management and habitat restoration. Workshops will use 1) the project site as a model and 2) nearby City-owned (Bluffside Park) and University-leased (Krueger Woods) lands for hands-on, experiential learning and experimentation.

The WSU Arboretum and Land Stewardship Committee will develop a series of workshops, grounded in Aldo Leopold’s Land Ethic, to provide participants with practical approaches for developing and maintaining environmentally sustainable landscapes. With the Garvin Heights project site as a model, and using a learning-by-doing approach, workshops will demonstrate the principles and best practices (e.g., methods, skills, and techniques) of invasive plant control. A hands-on approach will educate participants in the safe use of tools, equipment, and materials.

  • July 2016 - Start of 3-year project. In preparation for the project start, the Conservation Corps of MN and IA cleared invasive shrubs from a 0.5-hectare portion of bur oak savanna adjacent to the parking lot. Cut brush was piled for drying. Piles will be burned during winter to avoid sterilizing the soil beneath the piles, inhibiting later restoration efforts.
  • August 2016 - Professional Science Masters graduate student Ryan Walsh joined the project team. He will be assisting with all aspects of the project, and conducting a research project focused on the restoration effort.
  • September 2016 - The WSU Plant Ecology class began a series of assessments at the project site. They collected a variety of data on the recently cleared savanna: the densities of buckthorn and honeysuckle seedlings and yearlings, tree species and size, and canopy cover. Senior Biology major Margaret Duffy began surveys of bird species abundances on the project site during the fall migration period as her senior capstone research project. Senior Biology major Bonnie Hammack began her senior project to assess the impact of goat browsing on buckthorn within the bur oak savanna at the project site. Three different plant lists were produced for the project site: 1) plants currently growing on-site, 2) plants that were seeded on-site during earlier restoration efforts, and 3) plants from the WSU Herbarium listed as having been collected on the project site. Project Manager Neal Mundahl gave a presentation to the Winona County Master Gardeners describing the project and its goals, highlighting the plants of the dry bluff prairies and savannas on the project site.
  • October 2016 - Final contracts were worked out with project subcontractors and a project agreement was developed between the City of Winona and Winona State University. Dry bluff prairie and savanna habitats were preliminarily delineated using GPS.
  • November 2016 - The Winona City Council approved the project agreement. Diversity Landworks LLC brought 35 goats to the project site on 11 November and they remained on-site for 21 days. Goats browsed invasive shrubs in three separate paddocks during the 21 days: 10 days in an uncleared savanna, 4 days on the cleared savanna, and 7 days on the dry bluff prairie and savanna next to the developed overlook. As goats left each paddock, data were gathered on their impacts on buckthorn and other woody invasives.
  • December 2016 - Temporary signage was developed and erected on-site to inform park visitors about the project.
  • January 2017 - A crew of 10 Conservation Corps workers burned the buckthorn brush piles on the cleared bur oak savanna. All 47 piles were reduced to ash on a single, very cold (-3°F) morning. The piles had been produced the previous February when the savanna was cleared. Burning during winter with snow on the ground kept the fires from spreading and prevented the ground from becoming sterilized by the heat.
  • April 2017 – WSU Ecology major Bonnie Hammack completed her capstone research on the initial effects of goat browsing on buckthorn. She determined that: 1) goats browsed more frequently on yearling than on seedling buckthorn; 2) over 65% of large buckthorn were completely girdled when goats fed on bark; and 3) goats preferred to eat bark from buckthorn 20 to 60 mm in diameter, mostly ignoring the smaller and larger plants.
  • May 2017 - The Conservation Corps of MN and IA conducted a prescribed burn on the oak savannah and dry bluff prairies at Garvin Heights on May 15. The fire was timed to kill the younger buckthorn plants that had leafed out recently. However, lack of fuel on the savannah resulted in a very spotty burn, which allowed many young buckthorn plants to survive.
  • June 2017 - Goats returned to Garvin Heights! Diversity Landworks brought in a herd of 70 goats on June 9 to browse on the young, growing buckthorn on the savannah and prairie. With plenty of food during the early part of the growing season, goats stayed on-site for 23 days. Large buckthorn that had been girdled by goats the previous November did not leaf out, but produced many basal sprouts which were eaten promptly by the goats. Goats also consumed the leaves and branch tips of younger buckthorn, especially in the cleared savannah. Although there was a lush ground cover of seedling buckthorn in the cleared savannah, goats appeared to focus mostly on the older buckthorn.
  • July/August 2017 – Although we had planned for the Conservation Corps of MN and IA to perform some additional removal of large buckthorn on the prairie and two uncleared savannah sections, they were called away for hurricane relief efforts in Texas and Florida. The combination of the prescribed spring burn and the June goat browsing had a noticeable effect on the plant community that developed on both prairie and savannah habitats during the summer months.
  • October 2017 – Goats spent 3 more weeks chewing their way through buckthorn at Garvin Heights. Based on observations to date, it appears that several large buckthorn “trees” will need to be cut and treated in the uncleared savannah, since goats cannot reach the lowest branches and appear unwilling to browse on the rough bark present on these old plants. There also continues to be a healthy seedbank of buckthorn in savannah habitats.
  • January 2018 – Planning work has begun for our first invasive plants workshop for area citizens. We hope to conduct a one-day workshop during June 2018 that will include both classroom instruction and a field trip to Garvin Heights. We hope to have local/regional experts present and discuss various invasive plant problems and how to deal with them. We want to time the workshop to coincide with the planned June grazing by goats at Garvin Heights, giving participants the opportunity to see this management strategy in action.

Next Steps: What we plan to do in 2018

  • One more treatment of prescribed goat grazing (June) on savannah habitats only.
  • Repeat habitat delineation with improved GPS system.
  • Additional invasive shrub removal from savannas and/or woodlands by Conservation Corps. Continuing surveys of plant and animal communities of project site by graduate and undergraduate students.
  • Planning and development of invasive plant management workshops by Ryan Walsh (graduate student), additional project personnel, and/or others. Development of plan for restoration seeding or planting of savanna and dry bluff prairie habitats.
  • Coordinate Friends of the WSU Arboretum volunteers for selective removal or treatment of invasive plants on lower dry bluff prairie.
  • Development of habitat-specific educational signage.