Wind is a significant physical risk to planted forests with a history of 500 years of damage events in New Zealand with estimates of present net worth reduction of 11% given 1% (area) of annual damage.
Thinning and felling are the two main forest management activities which have the potential to increase the risk of damage. These activities increase the wind exposure to the residual trees.
Risk of damage to stands is based in the interaction between the vulnerability of a stand to toppling or breakage (as measured by the critical wind speed) and the wind climate.
Under climate change, for stable stands that have a high critical wind speed, small to moderate changes in the strong wind climate may only have a negligible impact on the risk of damage. However, for those stands which have low critical wind speeds, even relatively small changes in the wind climate could have a large impact on the risk of damage. If the wind climate becomes more variable, then the risk of damage will increase.
Modelling projections of changes to wind under climate change is problematic, as it can vary significantly over short distances and time periods.
A consistent signal from the climate projection is that there will be an increase in westerly wind circulation especially in winter and spring, but this may reduce in summer. This drives the projected increase in mean annual precipitation in the west and the decrease in the east.