Trees are dynamic, continually self-optimizing organisms, they maintain both their physiological functions and their structural integrity. Thus, the often massive structure of a mature tree above ground, consisting of the stem, branches, twigs and the attached foliage, is highly efficient in intercepting, using and storing solar energy, while also bearing its own weight and dissipating the potentially damaging forces of the wind.
Below ground, although far less obvious, the extensive root system is equally efficient both in providing anchorage and in pervading the soil in order to absorb the water and mineral nutrients that are essential for survival, growth, flowering and fruiting.
This standard gives general recommendations for tree work. It gives guidance on management options for established trees (including soil care and tree felling) and overgrown hedges.
The principles of this standard may also be applied to some shrubs, which can have similar characteristics to trees.
This standard considers the impact of work on an individual tree in relation to neighbouring trees, but does not cover overall management of tree populations.
The need for tree work will sometimes become self-evident to tree owners and site managers in the course of their regular duties. Tree work ideally forms part of a planned programme of management, which includes the successional planting of trees well-suited to their surroundings.
Principles for assessing the potential advantages and disadvantages of various aspects of tree work are stated, where appropriate, in this standard. Where work is required, it is important for clients to be aware of both the advantages and disadvantages before deciding the course of action to follow.