Forest management and planning as an opportunity to control invasive alien tree species in Europe

On 1 January 2015 a new European regulation on invasive alien species entered in force. Key aspects of this regulation are the adoption of a list of invasive alien species which are of European Union concern, the requirement for specific prevention measures, the establishment of early detection and fast eradication measures, and the management of the widely spread invasive alien species. There are 73 invasive alien tree species in Europe, of which 28 have been used in forestry. An analysis of the most worrying alien species from the main European databases, DAISIE (www.europe-aliens.org) and EPPO (www.eppo.int), indicates that 4 tree species (Acacia dealbata, Ailanthus altissima, Prunus serotina, and Robinia pseudoacacia) are of particular concern. These species have detrimental effects on biodiversity and ecological processes. By taking appropriate measures, the forestry sector has the opportunity to become a major player in curbing future alien tree invasions. To support this idea, we performed a review of scientific literature on silvicultural measures aimed at reducing the spread of four main invasive alien tree species in Europe. This analysis highlighted the potential contribution of the forestry sector to promote the implementation of the European regulation; in fact prevention is one of the most important possible interventions foreseen by this new regulation, particularly given the role of the forestry sector as a potential introduction pathway. There is a wealth of experience on positive and negative responses of invasive alien species to forestry interventions. Indeed, several recent conservation projects aim at restoring habitats invaded by invasive alien trees of particular concern. This knowledge should be synthesized and further developed to help prevent and manage invasions in forests and adjacent habitats and to minimize the risks of invasive alien species. We thus recommend that decisions regarding the application of the regulation will include actors responsible for, or involved in, the management and use of forests and related semi-natural habitats in Natura 2000 sites and other protected areas.