Evaluating the invasiveness of Eucalyptus globulus in Portugal
Eucalyptus globulus (Myrtaceae) is native to Australia and has been introduced into several regions globally as a plantation species used for wood production. In California (US), where the species has been planted, it has escaped and become invasive along the coast. It is also invasive in Hawaii (US) and South Africa. Within the EPPO region, studies conducted in Spain have also shown that the species can show invasive behaviour. Portugal grows more E. globulus by area than any other country. A survey was conducted in Portugal along the edges of E. globulus plantations (aged between 4 and 42 years) to record escaped individuals. In total, 1 630 E. globulus individuals were recorded occurring outside of 67 plantations in 129 survey plots (10 x 10 m). More than 50 % of the individuals were taller than 1.3 m and 8 % of these were reproductive. Soil cover, the age of the mother trees and their reproductive output were factors most associated with the presence of established wild individuals. The distance of establishment from plantations was associated with natural drainage lines and the main wind direction. The authors highlight that more research is needed to assess the reproductive capacity of E. globulus escaping from plantations.
Sources
Deus E, Silva JS, Larcombe M, Catry FX, Queirós L, Santos P, Matias H, Aguas A, Rego FC (2019) Investigating the invasiveness of Eucalyptus globulus in Portugal: site-scale drivers, reproductive capacity and dispersal potential. Biological Invasions, https://doi.org/10.1007/s10530-019-01954-6