Deadwood and habitat in woods and trees: what the Forestry Commission and Forestry and Land Scotland say

This page reports what the official source says. It is not legal advice: ask the office named here. The documents below are woodland and forest guidance from Britain, written for foresters and woodland owners. They are not rules for a single garden tree. Veteran trees get their own page, pollards and veteran trees, and dead trees that are a hazard are covered in dead and hazard trees in tree work.

Why the bodies keep dead wood

The Forestry Commission practice guide by Humphrey and Bailey (2012) says up to a fifth of woodland species in the UK depend on dead or dying wood for some or all of their life cycle. It says that the more deadwood a wood holds, the greater its value for biodiversity, and that the amount is used as an international indicator of forest condition. It was written to help owners and managers meet the deadwood guidelines in the UK Forestry Standard.

The 2008 grant note for England says deadwood feeds a large and complex food chain and that its rotting creates humid, sheltered niches for invertebrates, plants and fungi. It also says that forestry and arboriculture had treated dead wood as a wasted resource, a danger, an obstacle or a source of disease, and that time and money had gone into removing it.

What each document says about standing and fallen wood

Document	What it says	Exception named
Forestry Commission, grant Operations Note 15, version 1.2, June 1, 2008	Trees dying or dead standing are left standing where safe, or made safe without felling the main stem if possible. Fallen wood stays in place if possible unless it blocks access. Windblown trees with lifted roots are called extremely valuable habitat, and some are kept.	Sites of high floristic value with little deadwood history, where continued removal is likely preferred. Elm and willow with watermark disease are named as disease exceptions.
Forestry Commission, practice guide, 2012	Try to avoid removing deadwood or veteran trees from a site completely. Covers protecting existing deadwood, expanding it and linking habitats.	A hazard tree that is valuable as deadwood needs an individual risk assessment by a competent person and specific control measures, with fencing as the example.
Forestry and Land Scotland, Appendix 6, undated PDF	Snags can be a health and safety risk. On clear-fells they are kept in corners or edges where they do not hinder restocking. High and Medium areas keep windblow, with Medium harvesting only windblow of significant value or windblow that poses a health and safety risk.	Health and safety risk is defined as deadwood that could fall on recreation routes, buildings or other infrastructure.

Scotland's three classes

The Forestry and Land Scotland appendix sorts coupes into High, Medium and Low deadwood ecological potential. Its High class takes in natural reserves, ancient semi-natural woodland, native pinewoods, riparian buffers, plantations on ancient woodland sites with high ecological potential, and wood pasture. For High and Medium areas the table says to retain all existing veteran trees and deadwood apart from health and safety risk. For Low areas, which are stands managed mainly for timber, it says to retain existing deadwood apart from health and safety risk and to keep it where it will not restrict future operations. It calls large-diameter deadwood, over 20 cm, particularly scarce on the national forest estate.

Branch wood and chipping

Operations Note 15 says branch wood from felling is ideally left in piles that shrink with repeated cutting. Where that is impractical, it names burning or mechanical chipping as options, and it says that chipped waste wood does not make good deadwood habitat, with some larger pieces left whole if chipping is used. The Scottish appendix describes stacking logs and brash at the edge or corner of a coupe, in what it calls deadwood centres. The 2012 practice guide says that where woodfuel other than stumps is left in piles, the piles are best taken out before invertebrates colonise them.

How much dead wood

Operations Note 15 sets a suggested minimum of 5 to 10 percent of average stand volume, or 20 cubic metres per hectare, as dead or decaying wood on sites other than those of high floristic value. Its sample-plot count uses dead or decaying stems over 15 cm in diameter and ignores smaller wood. The note also says too much dead wood can impede access, be a fire risk and change a wood to the harm of ground flora.

Safety next to people

The 2012 practice guide says the chance of people being injured by deadwood is generally very low. It calls for rigorous risk assessment where deadwood is by regularly used recreation areas, public paths, roads and car parks, or where people work. The steps it lists include zoning inspections by use, routing paths away from veteran trees, and making sure remedial work found by inspections is carried out. It adds that where deadwood work may harm a European Protected Species, a licence from the nature conservation agency is required. It points readers to the National Tree Safety Group for guidance on trees and risk.

Disease and pests

The 2008 note says deadwood is rarely the threat of disease that it is perceived to be, naming Dutch elm disease and watermark disease as exceptions. The 2012 guide says most bark beetles can use only stressed or newly dead trees. It names two exceptions: Ips typographus, which it says was not yet present in Britain when the guide was written, and Dendroctonus micans, which it says is present and can kill healthy trees.

Contains public sector information published by the Forestry Commission and licensed under the Open Government Licence.