Ancient Tree Forum

Why manage old trees?		Our reasons for managing old trees have changed over the centuries. Today we want to perpetuate for as long as possible our total population of ancient trees. We want to: Keep our old trees alive as long as possible Keep our special treescapes Provide the continuity of very special habitats Allow future generations of old trees to establish Safeguard the historical and landmark character of our environment and the genetic resource. Provide safe environments in which people can appreciate the aesthetic and character value of individual trees. Without recognition and care old trees can easily disappear from our lives.

Why is it important to understand aging and the decay process when assessing the management of old trees?		Trees do not have a fixed life span, however in natural conditions trees pass through three life phases. The ancient stage is reached when the successive growth increments have a reducing cross sectional area but the tree is still increasing in girth. The crown dies back and branches may be lost so leaf area is reduced and less photosynthesis takes place. This stage may be the longest in the life of the tree. The process of decay in trees is just starting to be understood. What is clear is that fungi have a fundamental role in the process. Wood has a very complex chemical structure and is very indigestible. It is the fungi, which start the process breaking the wood down into simpler molecules so that other organisms can take advantage of them. Unfortunately as the fruiting body of the fungus is the only part to be seen they are regularly misinterpreted. A minority of fungi are a primary cause of death. Decay and the resultant hollowing of a tree is part of a re- cycling process re- leasing important nutrients for the tree or other organisms to re-utilise. There are a tremendous number of potential niches which can be created by the different types of decay. The more dead wood a tree contains the more valuable it is. A living, decaying tree is better than a dead one. Old dead trees are more important if left standing. However damaged young trees may also be valuable sources of rot. Click here to go to the ecology section

Assessing and planning the management of individual ancient trees		Ancient trees are found in many different situations but each tree is an individual and needs to be assessed within its environment. Historical background and conservation value of trees is important in evaluating any proposed management. Complex issues need to be fully considered within the structure of a management plan. It is useful to separate individual trees into those that have been actively managed at some stage in their lives and those that have not. It is essential to be able to justify why active intervention is required. Nothing should be done to a tree unless there is a clear need. Great skill and a light touch are essential ingredients in management where there is an overriding need to cut a tree. As a rule do as little as possible. Great judgement is required to assess whether a tree will respond positively to cutting. One cannot justify experimenting on the grounds that there are plenty of ancient trees in the surrounding treescape � every individual tree is important. Different species of tree respond differently. How long a tree has been out of a cutting cycle is likely to be important. Timing of intervention is important. The amount of material to remove should be minimised. The effects of opening up the canopy should be considered.

Managing the environment of ancient trees		The surrounding land and its use around an old tree can be crucial to their wellbeing. Conditions in the soil will affect the roots and the mycorrhizal fungi associated with them. Minimise disturbance and inputs of substances and avoid physical damage to trees. Changes in grassland management or grazing regimes can dramatically affect ancient trees. Fires in bracken and heathland can also be a severe hazard. Compaction, cultivation and deep ploughing badly affect tree roots. Protection out to the drip line as a minimum is regularly advocated. In woodland ancient trees can soon be overtopped and suffocated by younger trees. However releasing ancients needs to be managed slowly and carefully to avoid them being shocked. Many of the important organisms associated with ancient trees are also found in fallen branches and dead wood. Size matters and the bigger the better although where there is a plentiful supply a range of natural sizes is useful. Ideally it should be left where it falls. Burning is a major source of damage to decaying wood and the surrounding environment. Standing and canopy decaying wood is extremely valuable habitat. Ring barking can create new standing decaying wood however trees treated in this way decay from the outside inwards � this is not as valuable as natural decay within the centre of trees. The more dead wood the better and ideally all should be left. Quality is better than quantity with the aim of providing a good representation of all successive stages of decay on site.

Treescape and cultural values		Ancient trees often influence the character of our landscapes. Managing the landscape involves retaining ancient trees and next generations of mature and young trees as well as planning new planting. It is important to mainain local distinctiveness including by carrying on traditional tree management practices such as pollarding.

Managing ancient trees for their associated organisms		Ancient trees are important because of the range of organisms that rely on them for habitats and niches. Often management means doing as little as possible or undoing damage caused by unsympathetic management practices. It is very important to consider how organisms link into the environment surrounding ancient trees. A great deal of advice is provided in Veteran Trees: A guide to good management.

Creating future generations of ancient trees		Choice of species, sources of suitable stock, siting, planting and subsequent management need to be carefully considered. It is essential to provide appropriate continuity of trees, especially those necessary for their associated organisms.

Safety and risk assessment		There is no such thing as a perfectly safe tree. The important management activity is to properly evaluate the hazard and assess the risk to a target. If a tree presents a risk it is necessary to take appropriate action to reduce the risk to an reasonable level.

Legal responsibilities		Legal obligations which may apply to ancient trees: Tree preservation orders Conservation areas Felling licenses SSSI/NNR/SAC Scheduled ancient monument Wildlife and Countryside Act � bats and other species Hedgerow legislation Owners/occupiers liability Health and safety

Surveying and recording		Tree surveys have been started in several areas and on several sites with large concentrations of ancient trees. A standard recording form is available from English Nature.

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