The State of the UK’s Oaks
Action Oak Research Coordinator
Action Oak recently published a new report, The State of the UK’s Oaks Report, focusing on the pressures currently affecting the UK’s two native oak tree species (Pedunculate Oak Quercus robur, and Sessile Oak Q.petraea).
The report identifies potential signs of resilience and recovery in the face of accumulating pressures and describes examples of management interventions and current best practice to ensure a long-term future for our native oaks. The report also details research on emerging risks that may threaten the future of this iconic tree, it highlights where the evidence gaps exist and the potential opportunities for future research, field trials and citizen science monitoring.
Action Oak is a partnership initiative hosted by the Royal Forestry Society and currently funded by DEFRA and through donations. It was launched in 2018, with the vision for a UK where our native oak trees are protected and flourish. Action Oak brings together charities, landowners and managers, governments and researchers, and projects such as Observatree from across the UK to ensure the latest knowledge and evidence are available and shared. Other Action Oak publications, include project reports and our Annual Reports that bring together recent research developments, innovations in oak health solutions, and examples of best practice.
Oak trees have great historical, cultural and social significance in the UK, with more ancient native oaks in England than all other European countries combined. Ancient oaks are iconic historic landscapes features, carefully managed over hundreds of years to ensure a supply of wood for building, ships, tools, charcoal and bark for tanning. Today the delivery of environmental, social and economic benefit of oak woodlands in the UK has been estimated at £0.7billion/per year, a figure derived not just from direct timber value, but from the considerable ecosystem services value of oak trees. It is likely that this figure is an underestimate, as further work is ongoing to value the ecosystem services provided by urban oak trees.
The report brings together the considerable current knowledge and understanding of pests and diseases of oaks, detrimental conditions such as Acute oak decline and Chronic oak decline and the way in which the spiral of decline in oak trees progresses. It highlights that rapid and/or repeated exposure to multiple factors which critically stress trees leading to the downward spiral. While it is important to ensure monitoring for key pests and diseases, such as oak processionary moth, oak lace bug and powdery mildew, assessment of trees for all potential stressors, including soil compaction and drought combined with ensuring a healthy soil microbiome are also critical to avoid the decline spiral beginning.
Despite multiple stressors increasing the likelihood of the oak decline, there are some signs of hope as long term monitoring by the Forest Condition Survey has recorded a slight improvement in overall canopy condition. The analysis has highlighted the need to prioritise long term monitoring of oak condition using, for example, the latest remote sensing technology together with on the ground recording of the health of oaks by professional surveyors and citizen scientists. This will ensure early detection of change and enable appropriate targeted action to be taken when and where needed.
A key area for management practice is to improve the timber value of current oak woodlands and stands, many of which are less than 20ha and in private ownership. Ensuring sustainable supply chains of oak timber are in place is being supported through the work of Woodland Heritage, and their “Woodland to Workshop” course. While high timber quality is important, it is recognised that the selection of seed with traits for increased adaptation to environmental change and resilience to pests and diseases should also be a focus for future research and best practice trials, such as undertaken by the Future Trees Trust and Sotterley Estate in Suffolk. The report identified fewer younger oaks with stems of 21-50cm than 50 years ago. In the past, management would have ensured a continuous supply of oaks of various ages for a variety of uses. A greater number of younger trees could improve the capacity for adaptation to rapid environmental change.
The State of the UK’s Oaks report is an invaluable and accessible resource on our current knowledge on oak health and how this is informing best practice in management. The Summary Analysis document has all the key facts and figures, while the full report also includes more detailed accounts and case studies. To mark the launch of the report, a webinar was held on the 17th March 2026 including a panel discussion about the report and findings.
If you have any concerns about oak tree health, the Observatree Host of the Month for oaks is a great place to start; it also links to their information on oak pests and diseases. TreeAlert can be used to report signs of ill-health on oaks. Early warning is key to preventing outbreaks of new pest and disease arrivals and is an important part of preventing oak decline and ensuring our native oak trees are protected and flourish. You can also sign up to our newsletter to stay in touch with Action Oak work.