Social sciences perspectives: multidisciplinary project about the invasion of Prunus serotina in the Compiègne forest, France
In the framework of the French research project “Invabio”, a multidisciplinary project has been started on the invasion of the Compiègne forest in Picardie region by Prunus serotina (Rosaceae, EPPO List of IAP) originating from North America. The project gathers ecologists, geographers, mathematicians, sociologists, anthropologists and land managers to improve understanding of the invasive dynamic of this tree in the Compiègne forest. Ethnology has been used in the project to understand how P. serotina was perceived in the forest, and how information circulated between the general public and professionals of the forestry sector. The objective of this study was to consider the role that an invasive species (i.e. Prunus serotina) could play in ecological changes, and how local actors/stakeholders perceive this species which seems to be blamed for overall ecological changes.
History of the introduction
P. serotina was introduced during the 19th century in Compiègne, and it was only in the 1970s that foresters understood that the species had spread and covered about one third of the forest. Nowadays, it covers more than 80% of the forest, sometimes in monospecific stands. P. serotina grows faster than commercial species such as Quercus spp. and Fagus spp. and outcompetes them, while it produces a low quality wood. It is supposed that P. serotina became established in Compiègne because of the aggressive forestry practices (perturbation of soil and clear cutting) in the 1960s-1980s, P. serotina was only considered as invasive in the 1990s, when the issue of invasive alien species became more widely spread by the media.
Opinions concerning the tree
Interviews revealed that (excluding the reactions of scientists or naturalists) P. serotina was appreciated by forest users: trekkers admire its foliage, horse riders eat its fruits, residents make marmalade out of its fruits, etc. Interviewed persons who had noticed the tree could not name it and referred to it as “the tree which is everywhere”.
Management responsibilities
Responsibilities for the management of the species were rejected by most parties: naturalists accused managers and foresters in particular of not taking any action; managers accused the general public and plant sellers; the latter blamed the Government as there is no legislation in place. In practice, management actions were therefore undertaken only by a small number of persons with a scientific background.
Among scientists it is accepted that P. serotina is a threat to biodiversity, but this type of impact may be difficult to grasp by non-scientists especially when such a biological invasion has taken place over a long period of time. Indeed, the invasion by P. serotina is too slow to be perceived by local residents. In addition, the perception of P. serotina has changed over time: at the beginning of the 20th century, P. serotina was considered as a valuable species that improved the soil litter under conifer forestry plantations.
The authors considered that a debate involving all the stakeholders was needed to judge the most fitting management actions and to improve communication.
Sources
Javelle A, Kalaora B, Decocq G (2010) De la validité d’une invasion biologique. Prunus serotina en forêt de Compiègne. Etudes rurales 185, 39-50.