Tree risk management is a balancing act between the value of a tree (as a living organism) and the risk posed by that tree.
Tree Risk Management
Placing a pound value on trees is tricky because their physical attributes are constantly changing; starting from the smallest seedling, they grow progressively bigger and then die!
Furthermore, the benefits they offer do not have obvious dimensions, which makes them tough to measure and even harder to reliably factor into the decision-making process.
For these reasons, trees have traditionally been given a low priority in urban management, with other more pressing demands such as social services and infrastructure taking the bulk of the funds.
However, there is an increasing body of evidence revealing that trees may be much more valuable than we thought.
Emerging research is showing that they can make a significant contribution to making our communities more resilient to the impacts of climate change.
Trees have the potential to dramatically reduce urban temperature extremes and buffer surges in rainwater runoff, creating safer and more comfortable living conditions.
They also absorb pollution, enhance ecological diversity and have a significant beneficial impact on human wellbeing; people that live near trees are healthier and happier.
Indeed, investment in trees has the potential to deliver astonishing rates of return, with a recent Natural England analysis of the NHS Walking the Way to Health Initiative showing that for every £1 spent on access to greenspace, there was a more than £7 return in terms of averted health costs!
This and other similar investigations are confirming what most of us already intuitively knew, i.e. that trees offer multiple benefits to our communities and we need more of them.
Despite these benefits, the presence of trees also increases the risk of harm through damage to structures from their growth and injuries to people if they fail.
When harm arises, liability must be established, and it is inevitable that probing questions about responsibility and management will be part of that process.
Statistics tell us that the risk of death from tree failures is very low; on average about six people a year are killed by trees compared to about 10 people a day killed by traffic!
Clearly, there is no need to panic, but it would be prudent for all land management professionals to be aware of tree responsibilities.
The challenge for tree owners is to balance the benefits trees provide against the risks from their presence in a way that the courts will support in the event of harm arising from failures.
Duty of Care Relating to Trees
In broad terms, a tree owner, and/or whoever has control over it (the duty holder), has a duty of care in both civil and criminal law to take reasonable management measures to avoid foreseeable injury or harm.
Duty holders are expected to consider the risks posed by their trees and manage those risks in a reasonable and proportionate way, usually through a tree survey.
There is well established case law upholding the principle that the standard of the duty of care varies according to the resources available to the duty holder, i.e. a large land owner such as an estate or a highway authority would be expected to apply a higher standard of management than smaller land owners such as residential householders.
In short, the law expects duty holders to act in a practical and sensible way, according to the size of their properties.
However, in the event that a duty holder is found neglectful of their duty of care in terms of checking, i.e. they did not have their trees checked where a significant potential for harm existed, it does not automatically follow that they will be liable for any harm that arises.
Liability will only flow from that negligence if it can be established that a competent check would have identified an unacceptable risk of harm and resulted in remedial works that would have prevented that harm occurring.
If a defect that resulted in failure would not have been found in a competent check then, irrespective of any negligence from not carrying out a check, the duty holder is unlikely to be held liable for the consequences of the failure.
This is a common scenario and often results in court examinations focusing on the competence of inspectors and whether causes of harm would have been discovered before the event.
Negligence, Liability and Acts of God
More specifically, negligence, liability and Acts of God are commonly used terms when discussing duty of care and how blame will be apportioned in the event of harm arising.
Although they are the subject of detailed legal definitions, for the purposes of this discussion, their everyday meaning during normal use is more helpful.
Negligence occurs when someone fails to do something that a reasonable person would have done.
Liability is where the responsibility lies when something happens, i.e. who is to blame, with an implication that this is where compensation may be due for any harm that arises.
An Act of God means an event that is beyond human control, i.e. there were no obvious indications that it was going to happen before the event.
Cases That Went to Court
When a tree fails and causes harm, court deliberations often focus around the adequacy of the inspection regime, i.e. whether an inspection was necessary, the nature of the inspection, the frequency of inspection and the competence of the inspector.
There are no simple answers to all these questions, but a recipe-based approach does not work, and the final decisions are made through the subjective interpretation of the evidence before a judge, in the context of relevant case law.
Duty holders have a responsibility to identify what practical tree management measures they should take to meet their duty of care in case a tree fails, and harm arises.
In that context, recent court cases provide an insight into how modern interpretations are likely to be applied and where the boundaries between reasonable and unreasonable management lie.
Since 2006, there have been four judgments from the lower courts that provide some limited pointers on how these matters may be viewed.
Poll v Bartholomew (2006)
This High Court case covered the standard of duty of care and decided that, in this set of circumstances, a drive-by check was not a sufficient level of inspection and the Claimant succeeded.
During the evidence, both tree experts jointly developed a broad definition for inspector competence, but this was agreed between them and not explored in depth during the case.
Selwyn-Smith v Gompels (2009)
This County Court case is useful because it reviews the long-standing legal principle that the standard of duty of care varies according to the size of the land holding of the tree owner.
It reaffirmed existing case law in that the lowest standard applies to residential householders and requires them to be aware of obvious defects, but this is unlikely to extend to them being familiar with detailed technical publications.
It was held that there were no obvious reasons for the householder to suspect the tree was going to fail and the Claimant was unsuccessful.
Cavanagh v Whitley (2018)
The case concerned a large, mature lime tree, leaning over a road, which fell following a storm, causing serious injury to the driver of a bus passing by.
It subsequently emerged that the tree had some structural decay, which it was alleged could have been discovered if the tree had been inspected more frequently (it had been inspected on a three-yearly cycle, which was agreed by the experts to be normally adequate for roadside trees).
The defendant council was found to be liable because it had not inspected the tree on a two-yearly cycle or properly vetted the credentials of its surveyor.
The Standard of Duty of Care for Householders
Establishing the potential for harm in the form of a zoning exercise would not need any specialist input or require a disproportionate allocation of resources, and so it would seem a reasonable minimum requirement for all duty holders.
If this process identifies trees that may present a significant potential for harm, then the standard of the duty of care for managing those trees will vary according to land holding.
As SelwynSmith v Gompels sets out, the lowest standard to be met will be for the smallest landowner with the least resources, i.e. the residential householder.
Although not spelled out word-for-word in these judgments, it is likely that householders would be expected to identify obvious defects such as dead branches, broken branches, external decay, large splits or cracks, fungal brackets, etc, and call in an expert if they did not know what to do.
However, it is unlikely that they would be expected to obtain or familiarise themselves with technical publications.
In summary, if a significant potential for harm is identified, a quick visual check looking for obvious defects, is likely to be enough for most duty holders to meet their duty of care at this lower end of the land holding spectrum.
The Standard of Duty of Care for Larger Landowners
At the other extreme, it is likely that large landowners with greater resources would be expected to know about, and operate according to, recognised published guidelines.
It would be expected that a large landowner would engage with a suitably experienced arborist to provide a regular inspection program with a frequency defined by the location of the tree in relation to targets (such as people or structures that can be subject to damage or harm).
It is suggested that a zoning strategy should be adopted to define inspection frequency on a site.
It may be that zone 1 would be an area of high target frequency (such as a highway) and trees within that zone or within falling distance of that zone would require more frequent inspection (i.e. every 6 months) other zones may require less frequent inspection (18 months, 36 months, 54 months etc.).
The timescales selected should account for a leaf on, leaf of inspection routine (to get the best possible picture of the tree year around).
Although formal qualification is not required by law, it is expected that a good background knowledge of arboriculture and its practices are required for any inspector.
For large landowners, a high competency level would be expected and a qualification such as Professional Tree Inspection would be ultimately desirable.
The Emerging Duty of Care
In summary, unless trees are so remote that there is no realistic potential for harm, it is likely that the courts will expect duty holders to proactively manage their trees.
In the first instance, all that is required is a quick visual check and more detailed inspection would only be necessary if this check revealed matters of concern.
This check should be carried out at least every five years, and possibly more frequently if there is an obvious elevated risk of harm.
It is likely that householders could carry out this visual check without any specific training, but the standard would be higher for larger land holders.
In these circumstances, it is likely that the tree inspector should at least have a working knowledge of trees and be able to identify and react appropriately to any significant defects.
However, there is no standard recipe for where the boundaries between these varying standards lie and ultimately, it will be a matter for the courts to decide.
In the event of harm, all duty holders should be prepared to justify and defend their decisions during examination in court, a formidable prospect and something that all aspiring tree inspectors should be mindful of.
Article was written by Rory Hobbs.
Article Source: http://www.graftingardeners.co.uk/trees-landowners-duty-of-care/