Forest condition is now assessed annually in most European countries. This Field Book provides details of assessment procedures used by the Forestry Commission in their main monitoring programme. Although this programme is restricted to Sitka spruce, Norway spruce, Scots pine, oak and beech, the techniques that are described are applicable with little or no modification to most other tree species. Crown density indices for the main conifers and broadleaves grown in Britain’s forests are illustrated in a sequence of colour photographs (five photographs for each species). While emphasis has been placed on the assessment of crown density, a variety of other indices are also used. These are described and an assessment system is provided for each parameter. The additional indices enable a full description to be made of the condition of a tree. This publication is no longer available in hard copy.