Control of Knotweed and other invasive species and experiences restoring native species in the Pacific Northwest US

Abstract

Invasive knotweed (Polygonum L. [Polygonaceae]) species are a significant threat to native ecological communities that occur in riparian areas and other vulnerable habitats. This project applied practical methods to control Bohemian knotweed (Polygonum x bohemicum). This species was controlled for 2 y prior to restoring appropriate native species for the Chehalis River Surge Plain Natural Area Preserve in Washington State (US). The invasive species Himalayan blackberry (Rubus discolor Weihe & Nees [Rosaceae]), scotsbroom (Cytisus scoparius (L.) Link [Fabaceae]), and reed canarygrass (Phalaris arundinacea L. Raeush [Poaceae]) were also controlled.