par Cawoy, Valérie 
;Lowry II, Porter;Stevart, Tariq
Référence AETFAT Congress (XXth: 13-17 January 2014: Stellenbosch, South Africa)
Publication Non publié, 2014
;Lowry II, Porter;Stevart, Tariq Référence AETFAT Congress (XXth: 13-17 January 2014: Stellenbosch, South Africa)
Publication Non publié, 2014
Poster de conférence
| Résumé : | Voluntarily or involuntarily, humans are responsible for an increasing number of introductions of exotic plants around the world. Some are naturalized and can become invasive, often competing with native species and representing a serious and growing threat to biodiversity. Because of their impact on the native flora, invasive species are becoming recognized globally as an important focus of fundamental and applied research, with the notable exception of Central Africa, where almost no invasives are documented. In Gabon, only 7 plant species are referenced as invasive in the “Global Invasive Species Database” (GISD), even though naturalization of many other exotic species has been documented. Industrial activities, including forestry and mining projects, can facilitate the establishment of invasive plants because exposed soil often provides favorable conditions for them. Efforts to assess potential impacts of such projects and to implement appropriate mitigation measures require that recognized or potential invasive species established on a project site be documented and identified early in the planning process, starting with the initial baseline studies. To identify potential invasive species from among those that have become naturalized at a mine site, we developed and implemented a method using online databases and field inventory work. First, a list of species known from Gabon and a list of species known as invasive globally (GISP, PIER – Pacific Island Ecosystems at Risk) were compared; 67 species were common to both lists. Based on available data, knowledge of their degree of invasiveness, and local botanical expertise, 22 potential seriously invasive species were added to the 7 already recognized as invasive in Gabon. Fieldwork showed that only 1 of the 7 species occurred on site (Psidium guajava), which was planted. Of the 22 potentially invasive species, 7 were encountered in or near the field site. Moreover, field work revealed 10 additional exotic species recognized as invasive or weedy in other countries. This first-ever study has thus shown the presence of several previously undocumented invasive plants in Gabon. Most invasives are, however, found in open places (villages, cities, along roads and in savannahs) and almost none occur in forest or along old logging tracks. |
