Author Haysom K.A. & Murphy S.T.

Year of publication 2003

Over the last century, plantation forestry using exotic trees has developed as an integral and crucial part of many national economies and environmental programmes. Planted trees and woody shrubs have also proved vital in improving the livelihoods of many of the world’s poor. As a result, countries, international organizations, programmes and industries have been exchanging forest reproductive material on an ever-increasing scale. Various studies and reviews have been published regarding the “weediness” of introduced trees and woody shrubs, but little attempt has been made to evaluate information on the global status of these species and their impacts. This report attempts to fill this gap. The aims of this study were to: conduct a global review of the status of invasiveness of introduced trees and woody shrubs; identify the possible link between planted forest development and the occurrence/risk of invasiveness; review the positive and negative impacts associated with invasiveness of the tree species; identify the planning, monitoring and management options in a forestry or agroforestry context; and highlight priority areas (geographic, thematic or species specific) for future in-depth studies. In the remainder of this section the global status of forestry is considered, as well as some definitions of invasiveness in the context of trees and woody shrubs.