Non-native, invasive species are a paramount concern in virtually all natural areas and, not surprisingly, ranked as the top vital sign for monitoring within the Klamath Network. Impacts of invasives threaten the core goals of the National Park Service. Invasive species are second only to habitat loss as a threat to native biodiversity (Wilcove et al. 1998). Impacts from invasives that can severely degrade native ecosystems include the replacement of native vegetation (Tilman 1999), the loss of rare species (King 1985), changes in ecosystem structure (Mack and D'Antonio 1998), alteration of nutrient cycles and soil chemistry (Ehrenfeld 2003), shifts in community productivity (Vitousek 1990), changes in water availability (D'Antonio and Mahall 1991), and alteration of disturbance regimes (Mack and D'Antonio 1998). Invasive species having these effects are ecosystem transformers. Invasive species capable of transforming ecosystems are the focus of this protocol.