Importance & Issues
Prairies and Garry oak woodlands, once extensive in the lowlands of Washington and Oregon, are some of the most endangered ecosystems in the region. Currently, less than 3% remain, and these areas usually are in a severely degraded condition, especially because of invasive non-native species and development. Prairies and oak woodlands are key to providing habitat for many federally or state listed species including Fender‘s Valley silverspot (Speyeria zerene bremnerii Edwards, federal species of concern), Taylor‘s checkerspot (Euphydryas editha taylori Edwards, federal candidate species), Mardon skipper (Polites mardon Edwards, federal candidate species), Island marble butterfly (Euchloe ausonides insulanus), and golden paintbrush (Castilleja levisecta, federal threatened species). Restoration of these ecosystems is a priority for the National Park Service both culturally and ecologically, as well as being priority for other federal and state agencies and private conservation partners. The goal of the prairie monitoring program is to detect and describe changes in the extent and quality of prairie (herbaceous) communities in San Juan Island National Historical Park to provide baseline information for restoration planning.