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

Abstract

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.

Physicochemical Analysis and Essential Oils Extraction of the Gorse (Ulex europaeus) and French Broom (Genista monspessulana), Two Highly Invasive Species in the Colombian Andes

“…Of the two species, U. europaeus is the most studied in terms of valorization of all its parts. U. europaeus has been used for livestock feed and fuel [28], bioherbicide [29], and compost [30]. In addition, components with biomarker [31], antiviral, antibacterial [32], fatty acid [33], and raw material for biopolymers properties have been extracted from the plant's tissues.…”

The Social Dimensions of Biological Invasions in South Africa

“…In South Africa, work by historians and, to a lesser degree, by researchers in other social science and humanities disciplines, has detailed the role that people play in facilitating biological invasions. In particular, many purposeful introductions have been driven by specific societal mind-sets or ethos, operating in different eras (Carruthers et al 2011;Kull et al 2011;Udo et al 2019), and humans facilitated the establishment of invasions by modifying species and landscapes. In South Africa and globally, understanding the social drivers and processes of species introductions is probably the best researched of the four thematic areas.…”

“…Species of interest to collectors can easily be bought online (e-commerce trade) which is a modern, easy and novel pathway of potential invasive species (Martin and Coetzee 2011;Humair et al 2015). Simultaneously, the growing ethos of either managing or preventing invasions might lead to fewer purposeful introductions (Carruthers et al 2011;Udo et al 2019), although the context of increasing global movement of people and goods could lead to more accidental introductions than in the past (Seebens et al 2017). For example, biofouling and ballast water has led to the recent introduction of a number of alien marine species along the South African coastline (Faulkner et al 2017.…”

The Invasive Niche, a Multidisciplinary Concept Illustrated by Gorse (Ulex Europaeus)

“…However, the presence of an alien species in a territory is not sufficient for the species to be considered as invasive and managed as such. As previously pointed out, the status of invasive species varies among ecologists but even more so among managers, public institutions, and populations, according to geographical areas, periods, and socio-economic context [27][28][29]. Understanding what can lead a species to be considered as invasive therefore implies taking into account not only natural factors (biological properties of the species and biophysical properties of the receiving territory), but also social factors (geographical and social characteristics of the territory).…”

“…In addition to occupying space and challenging local species, it is a pyrophilous species: gorse promotes the flammability of the vegetation, and fire promotes its seed germination [33]. Many countries have implemented control programs, the oldest of which dates back to the 1930s in New Zealand, while others were gradually implemented in Australia, Tasmania, Hawaii, Chile, and Reunion Island [29,31,34]. It has been a highly studied species since the 1970s and it is easily identifiable from afar.…”