Medusahead Ecology and Management: California Annual Grasslands to the Intermountain West

To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Weed Science Society of America and can be found at: http://www.bioone.org/loi/ipsm.The spread of medusahead across the western United States has severe implications for a wide range of ecosystem\ud services. Medusahead invasion reduces biodiversity, wildlife habitat and forage production, and often leads to\ud increased fire frequency and restoration costs. Medusahead is problematic in the Intermountain West and California\ud Annual Grasslands. The last review of medusahead ecology and management was completed 20 years ago. Since the\ud last review, there have been scientific advances in medusahead management suggesting a significant need to develop\ud an up-to-date synthesis. Medusahead continues to pose a serious threat to rangeland ecosystems. In this synthesis, we\ud present new information regarding the ecology of medusahead, suggest a framework for managing medusahead\ud based on invasion level, and identify research needs to further improve management of this invasive annual grass.\ud Success of different management practices varies between the Intermountain West and California Annual\ud Grasslands, signifying that the best management practices are those specifically tailored with consideration of\ud climate, soil, plant community characteristics, and management objectives. Prevention and control treatments that\ud are useful in the Intermountain West may not be practical or effective in the California Annual Grasslands and\ud vice-versa