From useful to invasive, the status of gorse on Reunion Island.

Species presently considered as invasive were often deliberately introduced. Which factors led them from being desired to being denounced and what trajectory did such a transition follow? Using the case of common gorse (Ulex europaeus) on Reunion Island, the aims of this study were first, to identify and describe the different status that were attributed to this species since its introduction; and second, to discern the factors that influenced their emergence and decline in the public sphere. Five types of status were identified for common gorse in Reunion (useful, nationalistic, indigenized, noxious weed, and invasive), each peaking at a certain time, and then reverting to a low-key presence. The emergence and dissemination of each status in the public sphere depends on how well the various narratives proposed about the plant by networks of legitimate actors match the socio-technical landscape, as well as on how these narratives appear within legal and institutional frameworks. In addition, translating a status into actions of management can bolster its trajectory in the public sphere. Lastly, the decline of a status can be explained by a gradual desynchronization between its cognitive, normative and/or instrumental dimensions and the local socio-technical landscape.