Seeding and transplanting rare Willamette Valley prairie plants for population restoration

Prairies and oak savannah habitats once dominated the valleys and foothills in western Oregon and southwestern Washington. Fire suppression, invasive species, and habitat loss have substantially reduced the quantity and quality of this habitat. Several plant species of this ecosystem are considered rare, threatened or endangered. Their survival may depend reintroduction and population augmentation, as well as habitat protection and targeted management. Here we report findings from a series of experiments which tested the best methods for reintroducing or augmenting 5 rare species: Aster curtus, Erigeron decumbens ssp. decumbens, Horkelia congesta ssp. congesta, Lomatium bradshawii, and Lupinus sulphureus ssp. kincaidii. This executive summary condenses 5 years of research at 7 sites into straight forward recommendations for each species. Detailed experimental results showing how we arrived at these recommendations can be found in the succeeding chapters.