Clayton Rugh and Karen Liu

Clayton Rugh, Ph.D., is general manager and technical director at Xero Flor America. He has authored more than 50 plant biology and environmental science publications, including 10 articles on green roof performance. Karen Liu, Ph.D., is product manager at Bonar Xeroflor GmbH. She has more than 15 years of research and development experience in roofing and green roofing and has published more than 20 articles on green roofs.