West Eugene Wetlands Habitat Monitoring at Greenhill, Oxbow West, and Fir Butte

This document summarizes habitat monitoring in the West Eugene Wetlands on land managed by the BLM Eugene District. In 2015, we monitored Fir Butte SE, and new areas at Oxbow West (NW), and Greenhill (N) to assess whether they were within the habitat targets for Threatened and Endangered species or offer potential habitat for nearby rare species.

At Fir Butte SE, we noted an increase of cover of both native and introduced species, with introduced grasses dominating the site. While native species cover increased slightly since 2012, it still remained low in comparison to introduced species cover. The increase in native species cover was most associated with an increase of Kincaid’s lupine at the site.

Greenhill N was established in 2015 as a new area to monitor at Greenhill. We noted higher cover of introduced species than natives at the site, however native species cover was quite high relative to species composition in other sites. The site hosted a diverse mix of grasses and forbs.

Oxbow West NW was established in 2015 as a new area to monitor at the site. At Oxbow West NW, we found higher cover of introduced species overall, however native species had relatively high cover. Introduced forbs were common when compared to native forbs. Native grasses had higher cover than introduced grasses at the site.

Cover of invasive species exceeded the thresholds for management (maximum 50% cover for invasive species) at all sites. Introduced species cover was extremely high at Fir Butte SE due to the high cover of introduced grasses present.

Cover of litter/thatch exceeded the thresholds for management (maximum 20% cover for litter) at all of the sites, most likely due to the high grass cover at all sites.