UK forests and woodlands are often of considerable value to biodiversity. There is now a growing need to evaluate the impacts of forest management on biodiversity, in order to maintain and enhance the wildlife value at the landscape scale. The development of biodiversity evaluation tools will enable forest and land managers to make informed choices at this scale in order to provide sustainable forest landscapes for the future. This Information Note explains the scientific principles behind the approach being developed as BEETLE – Biological and Environmental Evaluation Tools for Landscape Ecology.