Predicted versus actual invasiveness of climbing vines in Florida

Abstract

Climbing vines cause substantial ecological and economic harm, and are disproportionately represented among invasive plant species. Thus, the ability to identify likely vine invaders would enhance the effectiveness of both prevention and management. We tested whether the Weed Risk Assessment (WRA) accurately predicted the current invasion status of 84 non-native climbing vines in Florida. Seventeen percent of the species require further evaluation before risk of invasion can be determined. Of the remaining 70 species, the WRA predicted that 70% were at high risk for invasion, but only 50% of the 84 species are currently invasive in Florida. The status and risk prediction were inconsistent for 27% of the species: 15 non-invaders were predicted to be of high risk for invasion (i.e., false positive) and 4 invaders were predicted to be of low risk (i.e., false negative). Longer residence time in the flora was significantly correlated with higher invasion risk. Further investigation is necessary to identify whether residence time explains inconsistencies between risk and status conclusions, or whether the WRA over-predicts invasion risk. Nevertheless, the effects of invasive vines on native systems coupled with the influence of time on invasion status, suggest a precautionary approach is warranted when considering the introduction and management of non-native vines.