Kelly Gravuer
NatureServe, in cooperation with The Nature Conservancy and the U.S. National Park Service, developed an Invasive Species Assessment Protocol to categorize non-native vascular plants according to their negative impact on native biodiversity in a large geographic area such as a nation, state, or ecological region. This protocol is designed to make the process of assessing non-native plants transparent, objective, and systematic. The protocol assesses plant species individually for a specified region of interest and assigns each species an Invasive Species Impact Rank (I-Rank) of High, Medium, Low, or Insignificant to categorize its impact within that region. The protocol includes 20 questions, each with four scaled responses. Text comments and citations support each response. The questions are grouped in four themes: ecological impact, current distribution and abundance, trend in distribution and abundance, and management difficulty. A subrank is determined for each of the four themes, and the overall I-Rank is calculated from these subranks. NatureServe is using this protocol to assess the biodiversity impact of the approximately 3500 non-native vascular plants established in the United States; over 520 completed species assessments are now available on-line through NatureServe Explorer (www.natureserve.org/explorer/). NatureServe continues to seek funding and partnerships that will enable assessment of additional species, with the goal of creating a prioritized U.S. national list useful to land managers, regulators, consumers, and industries. The protocol is available at www.natureserve.org/getData/plantData.jsp and has already been adapted for use by several states.
Keywords: INVASIVE SPECIES, NON-NATIVE PLANTS, BIODIVERSITY, IMPACTS, RANKING
