Modelling wind risk to Eucalyptus globulus (Labill.) stands

Wind damage to commercial plantations and natural forests is a serious concern for forest owners and managers all over the world, with notable losses having been reported in the last few decades in Europe, the Americas, and Oceania. Wind-risk models such as ForestGALES allow for a good understanding of the dynamics involved in wind damage, and for calculations of risk to be made, therefore providing vital information on the best practices to minimise such risk. In this paper we parameterise ForestGALES for Eucalyptus globulus (Labill.), arguably one the most widespread and commercially important species for pulp and biomass production, with tree-pulling data obtained in Asturias, Spain. Despite the scarce data on tree and stand characteristics available for wind damaged stands of Eucalyptus spp., we provide an evaluation of our model's performance under different stocking densities by comparing our simulations with real wind damage data acquired from the literature. We show that ForestGALES is able to accurately model the critical wind speeds responsible for Eucalypts stand damage, hence extending the model's applicability to this important commercial genus. In line with good modelling practice, we present the results of a sensitivity analysis of the model, performed with a Global variance-based method. Our sensitivity analysis confirmed the main role of Dbh, stocking density, and tree height in driving the model outputs, and highlighted the importance of accurately knowing the size of any upwind gaps adjacent to a stand to reduce uncertainty in model predictions.