Arguably the single largest myth affecting Tree professionals, is the misconception with regards the extent of damage caused by tree roots. It is a misconception that has also entered the archaeological / heritage sector, with much blame levied at past plantations being planted too close to archaeological remains.
Little research actually exists, (proportionate to the huge quantity of variables to be considered) and whilst there is in existence many ‘guidelines’ these fall well short of actually being useful at all and certainly should not be used by the insurance industry or others as definitive.
In reality the situation on the ground is far worse and the myths with regards tree root damage are culpable of a huge amount of wrongful insurance decisions, unnecessary tree removal and also the spreading of a fear towards trees which is now widespread throughout suburban UK.
In my experience both in the UK and in France, (there is a huge difference in practice between the 2 countries), I have never come across a situation where a tree root is directly responsible for damage to a built structure. I have seen many examples where the lack of necessary and often legally obliged maintenance to structures has resulted in providing a niche in which tree seeds have been able to propagate. I have also come across many examples where the soil profile left in a garden or plot for landscaping following construction work is dangerous in itself and thus subsidence and other problems occur, which would have occurred without landscaping and planting, yet the latter receive the blame.
The hard truth is that tree professionals, (and they are professionals unlike many who feel they can contradict or ignore their advice), are left to pick up the pieces and yet should have been involved from the outset of planning and even with regards architectural design.
There is also at play a huge missing link in the processes of development in the UK. Further to the above the abuse of soils during construction is endemic and as unsustainable as it can get, even on so called sustainable development projects. It has reached a stage where you will simply not find a site where the soils have been remediated as they should be subsequent to development. Indeed you can hold the UK up as an example of using phytoremediation and bioremediation practices at all times – this is by default – the result of efforts by a poorly paid landscaper or forester who has no budget to do anything more than plant and hope for the best and in a bizarre paradox; the trees, which are ultimately blamed for future problems were actually the one factor that helped to alleviate that problem for many years previously. The ‘Landscape Architecture’ industry has done much to lessen such problems but without real governance and legal framework to deal with the issues, the costs involved shun good practice in favour of cheap practice.
The Arboricultural Association are amongst one of the best accreditation organisations in the UK , but despite the best of efforts in tackling poor journalism and general misconceptions by larger industries this is a battle little recognised beyond the arboricultural and forestry industry itself.
We continue to see the placing of untrue facts via the media into the public domain. At present many of these untruths are criticisms of now historic Forestry Commission practice. Archaeology, for which the UK has an obsession for, has been placed high up in the list of issues in relation to Multi Functional Forestry. I am not in disagreement with this, but some commentary on damage to archaeological sites by plantation forestry is somewhat overzealous. I know for a fact that many sites in the areas I used to work in in Argyll, the archaeological features were simply not even known about prior to initial surveys by Foresters.
A wee digression: In Kintyre and Knapdale, a forestry contractor used to construct forest tracks had an understandable urge when discovering large rocks to up end the rock and leave a monument, which looked identical to many of the standing stones in the further landscape. It was a form of signature of his work. In one location he discovered several such rocks and the temptation to create a stone circle was too much. The subsequent report following the archaeological survey, (as part of the Environmental Assessment required for all large new plantations), a considerable chunk of proposed planting area was removed to create a buffer zone around the historic monument, constructed just a month previously.
I have been to archaeological sites, which have subsequently been identified as having been damaged by roots, but there is absolutely no way this could have been possible, the distance needed to be covered by the tree roots was simply too far. I am sure there are locations where there has been damage, but they are rarer than the general public are being led to believe. The only times I have witnessed damage to sites of historic importance by tree roots it is as a result of natural regeneration of native trees.
Is the protection afforded by the ‘strimmed grass’ land management regime found at many Englishh Heritage sites any worse than the weed infested open ground of an historic site found within a forest plantation? I have always been disheartened when visiting English Heritage sites to discover that from Neolithic time, through to WWII a strimmed finish is the fashion, a misinterpretation which could easily confuse most people. It is a real shame that a taste of the land management of the period of time when these sites were in use cannot be displayed and maintained.
I would not advocate the French system, where the destruction caused by invasive species such as Robinia pseudoacacia, Fraxinus angustifolia or Ailanthus altissima remains largely unchecked and worse used as an example of ‘urban biodiversity’ benefit. There is a common ground between the UK and France and it would be easy to implement guidelines based on this.
Is the power of the insurance lobby simply too big to fight, is there simply too much money at risk here?
The current and ongoing UK situation however is bordering on criminal: Once in Devon, I had to investigate a case when an insurance company had refused to pay out with regards the subsidence of a garage; claiming an apple trees roots has caused the damage – the apple tree in question was more than 10metres from the garage, less than 10 years old and its roots had not even spread beyond a metre from its stem!
As a continuing theme in my blogs, I am referring back to the UK forestry panel, whose remit will apparently cover all trees and woodland in the UK. One hopes that certainly in regard to new planting, the constant message from the Arboricultural Association, Tree Council amongst others will be incorporated into policy and measures to ensure ongoing maintenance and the implementation of good practice as identified by these bodies and the forestry and arboricultural industry at large will become a fixed standard. But with the quoted prices of tree planting and retention that are currently being offered as incentives, particularly with regards carbon offsetting projects, it is impossible to believe that everyone has yet understood these concerns and that there will still be a huge amount of tree planting to occur in the UK, without any budget for future and essential maintenance both to protect the trees and also infrastructure.