Sheep may be a familiar sight around the Willamette River Valley, and thanks to a new study on ecosystem restoration, they could also be playing a significant new role in the restoration and management of wetland prairies.
The City of Eugene is experimenting with targeted grazing as an alternative to gas-powered mowers and burning to reduce invasive species and maintain biodiversity in the rapidly shrinking West Eugene Wetlands.
Though grazing has been used to assist with habitat restoration in other parts of the country, the project represents the Willamette Valley’s first experience with developing and evaluating sheep grazing as a restoration tool.
On Friday morning, project partner and Junction City resident Cody Wood brought his herd of 100 sheep out for a day of grazing at the city’s Coyote Plains mitigation bank site. The sheep, or “green grazers,” as they are called by Natural Area Restoration Supervisor Trevor Taylor, are intended to restore the prairies to their native harmony by reducing the amount of dominant vegetation, creating openings in the soil with their hooves and
fertilizing the land with their waste.
Local ecologists will study the sheep’s impact on the land parcels in comparison to three other habitat restoration techniques: mowing, haying and burning.
The project will span three years and test various methods for maintaining diverse, native plant communities. The experiment owes its creation to the U.S. Environmental Protection
Agency, which recently awarded $151,000 to the Lane Council of Governments, in partnership with the city of Eugene and the Institute of Applied Ecology, for wetland restoration and development studies.
Taylor said action is necessary to assist Willamette Valley wetland prairies, particularly the West Eugene Wetlands, which have been thrown out of balance by the encroachment of urban development and the introduction of aggressive foreign plant species during the past 150 years.
“Historically, the native prairies were burned regularly by the Native Americans,” Taylor said. “If you don’t disturb them, they tend to become dominated by a limited
number of aggressive species.”
Taylor explained that biodiversity produces many beneficial ecosystem functions, such as supporting pollinators, optimizing nutrient cycling and groundwater cleansing.
Many of the areas are dominated by a durable plant strain called tufted-hair grass, but
Taylor said the goal of targeted sheep grazing is to create open space to make room for other native plant species.
“We’re trying to understand ways of creating a habitat that is resistant to invasion and resilient to disruption,” he said.
According to the city’s Web site, the nearly 3,000-acre West Eugene Wetlands are composed mainly of “wet prairie, a grass- and wildflower-dominated habitat type historically common in our area, but rare today.”
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