Upland prairie is one of the rarest habitat types remaining in the Willamette Valley. As a result, it provides homes and habitat for several listed species, including Kincaid’s lupine and Fender’s blue butterfly. There is currently no market for upland prairie credits, but impacts to Fender’s blue butterfly habitat or projects with federal coordination requirements can trigger mitigation requirements under the Endangered Species Act. These requirements might be contained in a consultation on a road project or in a county-wide Habitat Conservation Plan. Since impacts to prairie are not tightly controlled, the emphasis was placed on preserving the highest quality remaining patches of upland prairie.

Counting on the Environment’s Prairie Credit Calculation Method

As the Counting on the Environment project reviewed existing metrics, it did not find an existing metric that meshed well with the other approved metrics or that had found common acceptance in Oregon. Paul Adamus, working with the focus group of state prairie experts, developed a new rapid assessment method for upland prairie.

The metric produces a functional score between 0 and 1 that is used to weight acreage to generate functional acres as a unit of trade. The metric’s required, rapid portion includes questions that establish the site qualifies as upland prairie, assess the site’s contextual value, and then scores the site-specific functions. The metric also includes an optional detailed assessment using vegetation plots. This portion is used to refine credit estimates and track performance over time.

Upland Prairie Habitat Calculation Documents
Prairie Crediting Procedure
Prairie Credit Calculator