Summary
This report collates evidence on the factors contributing to shake development, evaluates their relative impact, and offers recommendations for managers where possible.
Shake refers to the internal, longitudinal splitting of wood in a growing tree. It manifests as either ring shake (annular pattern) or star shake (radial pattern) and can only be definitively detected once the tree is felled. Oaks can exhibit either or both types, with star shakes being more common.
Shake can significantly degrade logs that might otherwise be suitable for high-value decorative or structural uses, reducing their value by up to 80%. This defect poses a major economic challenge to the UK growing and processing sectors, especially given the persistent shortage of larger, high-quality domestic hardwood sawlogs.
