Woodland ecosystems are integral to our health, well-being, security and economy, but they face a number of pressures including climate change, land-use intensification, and emerging pests and diseases. This Research Note explores the links between biodiversity, measured at different levels of organisation (genes, species and communities), and the ability of woodland ecosystems to withstand and adapt to changing conditions and disturbance. Using examples drawn from the literature, the Note identifies and discusses a range of biophysical attributes that can positively influence these different elements of woodland biodiversity and therefore enhance ecosystem resilience. These characteristics are considered at a range of spatial scales, from the fine-scale attributes of individual trees and stands, through to features characterising entire woodlands and the environmental condition, composition and configuration of the landscape contexts that they fall within. In acknowledgement of the intrinsic value of biodiverse woodlands, and of the multiple ecosystem services they provide, the Note emphasises the importance of taking action to safeguard biodiversity and to improve woodland resilience at these multiple scales. Some of the implications for forestry management are discussed; actions that can be taken to enhance biodiversity are highlighted according to the spatial scale of implementation and the organisational level of biodiversity affected. The information in this Note has been compiled for use by woodland managers, other practitioners and policy makers, with a focus on British woodlands in all their forms, from production forests to native woodlands.