Legal obligations in relation to trees
There is a legal requirement vested in tree owners, landlords and owners of facilities to ensure that their premises are ‘fit for purpose’ and safe to use by others. This responsibility and ‘Duty of Care’ stems from the ‘Owners Liability Act 1957 and the Health and Safety at Work Act 1974’.
Whilst trees can offer both aesthetic and environmental benefits, they have been known to fail structurally, particularly when not maintained to good arboricultural standards. If a tree branch were to fall or a tree collapse causing personal injury or damage to property, litigation could be brought to the injured parties.
In a court of law, the ability to provide evidence of routine tree inspection and corrective tree surgery is often sufficient to demonstrate that the owner of the tree has acted in a ‘reasonably practicable’ manner and thus behaved responsibly. Under such circumstance prosecution does not follow.
Trees are living organisms and are continuously changing.
Each year they produce new shoots, roots, structural wood and bark, which in turn maintains their physiological functions and structural strength.
Like any living organism, trees are vulnerable to an array of threats.
Here are some examples of threats to trees where risk of failure could be minimized if work is carried out.
Extreme wind and cold can cause structural damage to a tree.
If a tree is top heavy, poorly formed, has historic structural defects, is diseased or dying or has had its roots compromised by construction works this could increase the risk of breakage or failure when put under additional stress of severe weather.
Crown reduction, weight reduction, cable bracing, crown thinning and pollarding are just some of the techniques used to combat risk. We know that pruning to minimize the risk of failure works. On some of our longstanding projects the statistics speak for themselves: in the early stages of a particular tree care program of over eight thousand semi mature and mature trees, when there was high wind we would be called out in an emergency to clear failed trees in abundance. Four years into the program after regular survey and recommended pruning being carried out, it would be rare to be called out at all, over the course of four years, not only did the client have a healthy tree stock with a low risk of hazard in public areas, but they actually started to reduce the spend on tree care because the work simply was not reactive, but proactive.
Pests and diseases
It is essential that trees are inspected regularly, but particularly if you think something is not right e.g. early leaf drop, discoloration of foliage, fungal fruiting bodies, bleeding from stems etc. These are simple signs which the layman can see.
Calling in the experts and early diagnosis could lead to action being taken to improve the health of the tree or stop the spread of an invasive problem, but essentially where a tree is located in an area used by people or near to valuable structures which could be damaged, there may be risk of structural failure leading to branches and limbs falling or complete tree failure all of which could have catastrophic consequences. Pruning or controlled felling is clearly a smarter option to an act of god.
Conflicts with people
Lack of light, bird droppings, unknown risk of falling, leaf drop; these are all common complaints which occur. As construction land becomes more and more scarce and homes are squeezed into smaller spaces, often humans and trees have to live in close proximity to one another, and this is where the conflicts begin.
Crown reduction, crown lifting, crown thinning and pollarding are some of the techniques to manage trees in confined spaces which avoid removal of valuable trees in urban areas. Often pruning solutions can be found to resolve disputes between tree owners and disgruntled neighbours.
This is probably one of the biggest risks to trees which we experience and ironically the place where existing trees are so valuable.
Many developers, although regulated by planning and given clear guidelines as to the method to be taken where trees and construction crosses over, are not sympathetic to tree preservation and care.
Severe severing of roots, root compaction from heavy plant and soil contamination are common factors causing risks to trees. Often it can be years before any of the affects can be noticed; usually it will start with die back of the top tips on one side of the crown and then develop into complete die back on one side, which often can be traced to a utility trench, footing or new road. Root pruning, fencing of root protection zones, but especially training and education of site managers are all ways avoiding this damage.