The project investigated the resilience of Sitka spruce forests in Scotland to climate change and the potential threat posed by Ips typographus (the European spruce bark beetle). Using a combination of literature reviews, climate modelling, and expert workshops, the report evaluates the likelihood of beetle establishment and potential for damaging outbreaks under future climate scenarios. 

Findings indicate that the potential for the beetle to become established is currently moderate, with conditions becoming more favourable with climate change and increasing the risk of localised outbreaks in the shorter term.  A combination of high summer temperatures and prolonged droughts was identified as a potential risk factor that could lead to larger-scale outbreaks in future. Should the beetle become established in Scotland, the risk of such larger-scale outbreaks is currently low but rising to moderate, then high within the next Sitka rotation of 30-50 years. It is higher in South Scotland than in the North, which appears to be relatively protected, at least for the duration of the next rotation. The long-term impact of such outbreaks might be beyond normal sustainable felling programmes, as seen in parts of Europe since the early 2000s. 

The study highlights the importance of continuing surveillance, detection and eradication actions along with proactive management and longer term planning such as managing storm damage and diversification of forests. 

Knowledge gaps were also identified, particularly in understanding the combined effect of windthrow, drought and other extreme events on the likelihood of establishment and potential impact on Scottish forests, and any variations in Sitka spruce response to beetle attack relative to Norway spruce.