Iodine Staining Test

The new BS3998:2010 Tree Work – Recommendations makes an interesting reference to Starch Testing (page 19, section 7.2.1) which I’m sure may flummox many practicing Arborists.

An Iodine Stain can be used to assess the energy levels of a tree and should, in the first instance, be a simple field test. The test ascertains the concentration of starch in a sample from the last three sapwood increments taken from small cores representative of the whole tree.

Trees require energy for all functions, including respiration and reproduction of cells, growing new tissues, and maintaining defences against invading insects and disease. Some of this energy comes directly from the leaves, as it is made. The rest comes from the stored reserves.

During the growing season, the tree manufactures sugars and carbohydrates in the foliage. These compounds contain the energy needed for metabolism. Whatever is not used for current needs in the tree is transported to the woody tissues and converted to starches for storage in the living cells of the branch, trunk, and root wood. The amount of available stored energy within the tree is an indication of the vigour of that tree, and its general health.

The starch content of the tree will help guide the Arborist as to the level of pruning any particular tree will tolerate.

There are some limitations to the testing including species and site specific discrepancies however the test could prove a useful tool and should perhaps become a common precursor to prescribing tree surgery operations.

We are currently evaluating the practicalities of the test for field use and are planning to offer a workshop in the not too distant future to raise of awareness of the process and hopefully encourage its use amongst tree surgeons/tree care professionals.

Industry Best Practice – Tree Work BS3998:2010

As a progressive company we feel it important to connect with the industry at a local level. To this end we recently showed initiative by being one of the first in the country to organise an event to highlight the recent changes to BS3998 – Tree Work Recommendations.

The new British Standard came into force as of the 31st December 2010 and represents a long overdue revision to the very much outdated 1989 Standard. The Arboricultural industry has evolved beyond recognition over the last 20 years and this new BS should help to raise the profile of proper tree care and bring best practice to a wide audience.

Aspect Training Seminar – Jan 2011

Aspect Tree Consultancy organised a seminar to disseminate information contained in the new BS which was held on the 25th January 2011 and was kindly supported by South Hams District Council and The Arboricultural Association.

Sixty delegates from across the South West attended the event, which included a mix of Tree Surgeons and Arboricultural Contractors, together with a strong representation of Local Authority Tree Officers and officials, including South Hams District Council, Plymouth City Council, Torbay Council, East Devon District Council, West Devon District Council and Dartmoor National Park.

Presentations were given by Dominic Scanlon, Chris Widdicombe and Jon Kiely of Aspect Tree Consultancy, focussing on the technical content of the Standard. Simon Putt of South Hams District Council then followed on offering a Tree Officer’s perspective on how the changes will affect those wanting to apply for works and particularly what level of information will now be required in order that applications for tree work are registered.

BS 3998:2010 Tree Work – Recommendations

The new document moves the emphasis on how to prune and the selection of final pruning cuts to a greater emphasis on why and when to prune trees or undertake works. This is a welcome change as it forces users of the Standard to consider carefully if trees will tolerate the works and if the works will be carried out at a time of year that will cause the least stress and damage to the tree.

The addition of a flow chart that covers the process from instruction to completion and follow up of tree works operations provides a clear, easy guide to Arboriculturists on the thought processes they need to follow.

The Standard also covers retention of stumps and more specialist works to Veteran trees. This reflects the changes not only in the industry but wider society on the importance of wildlife habitats, their retention and management. The Standard also makes it clear that consideration needs to be given to ensure these practices are carried out where appropriate.

Importantly the Standard now provides much greater guidance on tree pruning operations especially the appropriate level of the volume of branch material that can and should be removed without causing the tree damage. The operation of crown reduction is clarified and this is extremely welcome especially as it appears to be an area where the old Standard was much misunderstood. If implemented correctly the Standard provides an important step forward for the industry and for tree care.

There is now an emphasis on the time of year that works can be carried out. An important finding from research is that works during Spring and Autumn, when trees are using the most energy in their growth cycle, can be very damaging to their long-term health. Consideration now needs to be given to when and if the tree will tolerate the proposed works. If the tree is not in an optimal condition the works may need to be phased over a number of years, especially if the level of branch removal exceeds recommended levels.

There is also an important emphasis on assessing the condition of the tree prior to recommending what works are appropriate as an attempt to predict how it will respond.

The Soil

Our industry’s appreciation of the importance of the condition of the soil in relation to tree health has altered significantly over the last few years. The Standard now includes more detail on techniques for soil improvement, protection and care. Whilst other areas of the Standard pose a constraint on tree surgery operations this area provides an important opportunity and helps us move from an industry dominated by tree surgeons to an industry of tree care professionals.

Tree Work Applications

All these changes will alter the level of information required by Local Planning Authorities when registering and considering tree work applications. This may include tighter specifications on how much material is being removed (pruning), soil protection measures, and phasing of tree works.

The changes will have an effect on any member of the general public or organisation who own or manage trees.

The revised Standard will have an enormous impact on the quality and level of tree care, which will now be expected of tree surgeons and contractors. South Hams District Council Tree Officer, Simon Putt, explained the requirements now expected from members of the public and contractors wishing to specify or undertake works to protected trees, and he went on to say that if the relevant detailed information is not provided at the application stage, it would result in the Local Authority failing to register the application.

Tree Surgeons in the South West

Paul Smith of the Arboricultural Association gave a presentation explaining how the association was supporting its members and the benefits which membership brings. Paul, who is also responsible for the AA Approved Contractor Scheme (a vetting process for tree work contractors), also explained how approved status is now more easily achievable and accessible for smaller companies.

The feedback from delegates was extremely positive and encouraging, and seeing as we had to turn people away because the venue was full, we are thinking of running the event again in the near future.

The revised BS 3998 document can be obtained from the British Standards Institute.