WNA Prairie Restoration Program

Practicing the Art of Land Recovery: Upland Restoration in the Whilamut Natural Area

Whilamut Natural Area Butterfly MeadowThe Whilamut Natural Area (WNA) is an urban park that has been recognized by the City of Eugene as valuable habitat to be restored back to its natural plant communities – upland prairie, oak savanna, and riparian woodland. The 3-acre WNA Butterfly Meadow is surrounded by over 280 acres of parkland bordering the Willamette River, providing an important buffer zone for wildlife species. The rehabilitation of the Whilamut Natural Area Butterfly Meadow directly affects our watershed by linking critical bioregions serving as functional greenways along the Willamette River. Over 24 species of butterflies once existed on upland prairie habitat. Now only seven species are fully restricted to remaining remnant prairie ecosystems.

In 2004, the great copper butterfly (Lycaena xanthoides), a species absent since the 1970s, was discovered in prairie ecosystems in the West Eugene wetlands. A long-term priority for the WNA is to provide an upland corridor for rare butterfly species currently returning and increasing in population throughout prairie ecosystems on the edges and within the urban interface of Eugene by introducing a large source of native nectar and host plants. In June 2004, with foundation support, WRP initiated a seed collection and nursery program that targeted species suitable for prairie ecosystems. In spring of 2005, WRP staff and volunteers placed 15,000 square feet of solarization plastic onto a tilled portion of the butterfly meadow, initiating Phase I of our rehabilitation project. In October 2005, staff and local youth removed the plastic and re-seeded the area with a native mix of forbs and grasses. Staff and volunteers also planted across the site hundreds of plants consisting of over 15 species grown in WRP’s nursery. In spring 2006, WRP staff and local youth continued Phase I by intensively hand weeding the site. Volunteers from a youth group aided WRP in placing over 16,000 square feet of solarization plastic and shade cloth directly adjacent to the Phase I site.

To date, we have inventoried over 25 species of native prairie plants growing in thick densities through the 15,000 square foot area. Species such as Rumex salicifolius and Grindelia integrifolia, primary host and nectar sources for the great copper butterfly, had a 95% survival rate. Other butterfly host and nectar species such as Sidalcea virgata, Brodeaea hyacinthia, and Lupinus rivularis, all exhibited high density and had over 90% survival rates in the site. There is a strong need for incorporating community participation in prairie restoration projects within the urban boundary to continue support for the regeneration of prairie ecosystems. We have been actively working with students from the Network Charter School on this project since 2005. Please read our front-page article in the Fall 2006 newsletter for more information on this project.

Directions to Whilamut Natural Area: Turn into the main Alton Baker Park Entrance, follow the road through the park, past parking lots and Cuthbert Amphitheater. The Whilamut Natural Area is on the right, after the Community Gardens, before ballards close the road. Park in the gravel lot by the Gardens. It is also located directly off the Bike Path on the north side of the Willamette River by Autzen Stadium and Nearby Nature Yurt.

Species Planted At WNA

Butterfly Meadow Project Photos