Chalara dieback of ash – (Chalara fraxinea)

Tree health has been a hot topic in recent weeks following the introduction of a new tree disease into the UK. There has been much press coverage regarding the potentially serious threat to one of our most valuable native trees – Ash.

Chalara dieback of ash is a serious disease of ash trees caused by a fungus called Chalara Fraxinea. The disease causes leaf loss and crown dieback in affected trees, and usually leads to tree death.

The disease appears to have been introduced on imported nursery stock and is now being treated as a quarantine pest under national emergency measures. However, now that the disease has been found in older trees (East Anglia, Kent and Essex) with no apparent connection with plants supplied by nurseries, government scientists are investigating the possibility that it might have entered the UK by natural means; such as wind borne spores or birds coming across the North Sea.

It is still very early to judge what the position is and the Forestry Commission and DEFRA are still gathering information so the full impact that the disease will have in England is not yet known.

If we look to the other countries that have suffered with the disease it looks very likely that 60-90% of UK ash trees will be infected in the foreseeable future. Ash trees make up 5% of the UK tree population so this will have a significant impact on our towns and countryside.

The disease is a fungus that readily infects young trees and saplings but affects older trees more slowly. The main spread of the disease is through the movement of young plants and this is now being controlled. The majority of the reported outbreaks relate to young planting with a few cases of mature trees being affected.

The disease spreads slowly on its own (12-20 miles per year) and mainly through spores on leaf litter and twigs from June to September. This means that we will get a much better idea of the extent of the spread by the end of next summer. Our current knowledge of the spread is based on sample plots inspected by DEFRA.

There are no reasonable controls (at the moment) and it looks very likely that the policy will be to allow the disease to run its course rather than undertake sanitation felling. The problem with sanitation felling (removing all the trees in an area around an outbreak) is that it is expensive for landowners and you lose trees that may be resistant to the disease. So in the long term it is better to identify the resistant trees so that we can re-establish the ash tree population.

The current advice is that mature trees may live for some time after infection so felling trees hastily may be too harsh a measure when some benefit can still be gained from keeping the tree.

For more information go to: http://www.forestry.gov.uk/chalara

Winter Weather Warnings

The recent and continued wet weather experienced across the UK and particularly here in the west country may pose problems for trees – the main concerns at this time of the year are the increased likelihood of winter storms and high winds.

Flooding can alter the soil structure by allowing the various aggregates to fall apart, thus resulting in a lack of, or reduced soil cohesion.  Saturated soils and high winds can increase the risk of trees falling over.  It is probably worth keeping an eye out for obvious signs/symptoms of damage; such as a leaning tree with recent soil or ground disturbance around its base.

Flooding can cause numerous problems for trees depending on the length of time the soil around them is saturated or submerged.  One such problem is the increased risk of water born ‘nasties’ such as Phytopthora which thrives in wet soils and has the ability to kill trees.

Tree growth in the following growing season may also be affected and soils which have been subjected to prolonged flooding may need to be decompacted or aerated and mulched with good quality organic matter to aid recovery.

It is important to be vigilant and to assess trees following any extreme weather event, but to also remember that the impacts of these events may be responsible for later symptoms of poor growth, decline or even mortality.

Aspect Office Move

After a successful 4 year start up period, Aspect Tree Consultancy has now moved to a new office in Hamlyn House, Buckfastleigh. It has great access to the A38, Devon, Cornwall and beyond. Situated on the top floor of an old mill, it meets our IT and space needs giving us the opportunity to keep growing.

We are also pleased to welcome two new members of staff.

We have been joined by:

Neil Cumming – an engineer with arboricultural qualifications and extensive experience in business and construction. Neil is running the arboricultural site monitoring as well as supporting the rest of the team.

Matt Paxton – Matt is providing all our CAD support and is a qualified engineer and CAD Technician.

The expansion has allowed us to strengthen the office support for the team and to speed up turnaround times for reports and plans.

BS3998:2010 National Roadshow

Following our very successful training seminar relating to the changes made to the revised British Standard B.S.3998:2010 Tree Work Recommendations, which we ran on a local level in Devon, we have been invited by the Arboricultural Association, to run the event on a national level.

The invitation has been extended to Aspect Tree Consultancy to run the event at various venues across the country in association with the Arboricultural Association.

Dominic Scanlon from Aspect and Paul Smith from the AA will be presenting the seminar on the following dates at the following locations.

25th March – Newquay, Cornwall
29th March – Haywards Heath, Sussex
30th March – Needham Market, Suffolk
6th April – Leicester, Leicestershire
7th April – Preston, Lancashire
12th April – Perth, Scotland

Further information and booking details can be obtained from the AA website. www.trees.org.uk

The event highlights important changes which have been made to the British Standard which was last updated in 1989, since which time there has been significant progress within the tree care industry, brought about by research and development, changes to the Health & Safety and Wildlife & Habitat legislation, together with the introduction of new and improved equipment to aid tree climbing and pruning techniques/operations.

The changes call for more considered tree work specifications and improved practices when undertaking tree works.  The new document also emphasises the need to consider the whole tree including the management of the rooting environment and the wildlife which they often support and the habitat that they provide. All in all, the revised standard removes the emphasis on target pruning and tree surgery and focuses more on tree care which in my opinion is a very refreshing and welcome approach.

These changes will impact upon anyone who owns or manages trees and particularly so when applying to undertake works to protected trees or woodlands when compliance with the new standard will be essential.

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.

Tree Planting – why is it so difficult?

Tree Planting – common problems:

Successful tree planting is easy but it relies on a few simple things being done properly. In the UK there has been a superb tradition of planting from the impressive remnants of the Victorian era that dominate our towns and cities to the large scale forestry of the 1950’s.

This makes it all the more puzzling to see so much poor quality planting across the country especially on new development sites. You don’t have to travel very far to see young trees struggling to survive due to poor species selection, poor nursery stock, bad planting technique and a lack of aftercare and maintenance.

Many tree planting contracts fail to enforce the aftercare that is vital to the trees surviving. In addition to this trees are so often planted into poor soil and badly designed pits. This terrible state of affairs is not restricted to any particular sector. Local Authority planting schemes appear as likely to see heavy losses as private sector schemes.

Private developers regularly need to remove trees in order to provide an appropriate layout design and Local Planning Authorities need to balance tree preservation with the need to find housing or employment land. Tree planting is a vital part of the development process both to mitigate for the loss of trees and to provide new trees that will mature along with the development. Trees are a key part of sustainable development.

The private sector often fails to design the tree planting into the scheme with trees stuffed in as an after thought, often into poor quality soil and a very restricted volume of soil. Then to compound the problem Local Planning Authorities fail to enforce the relevant planning conditions and maintenance and aftercare become forgotten. The result is so often a struggling stock of trees ill equipped to survive the harsh conditions that they have been planted into.

The blame for this lies across the industries. The private sector fails to get the advice it needs, LPA fail to impose their powers and the Arboricultural industry fails to make its voice heard.

There also appears to be a lack of good knowledge amongst professionals. Landscape Architects frequently seem to get planting wrong and this normally relates to the provision of ample soil or correct tree pits. This is a failure of the Arboricultural Industry to educate allied professionals.

Tree Planting Solutions:

There is now so much research available to tell us which methods of tree planting are the most successful. Technology has provided a wide range of materials and off the shelf systems to provide good planting conditions in a wide range of locations. The availability of mature planting stock and a wide range of tree species mean that there is no excuse to get planting wrong.

Ideally trees are planted into a larger area of open ground with minimal weed competition and a maximum volume of soil. Larger planting areas can only be designed into a scheme from the very beginning and not designated as an after thought or to use up left over pieces of ground.

Obviously the constraints of the real world mean that space is at a premium on any site. Numerous products and techniques are available to allow tree planting to share space with other uses. In mainland Europe it is common to plant trees into structural soil and/or Amsterdam soil. These are soils that are compacted and can bear the load of paving and/or parking. This means that larger planting pits can be provided to sustain trees into maturity. In addition to this numerous products can direct root growth away from infrastructure reducing damage to paving and utilities. Once again these solutions need careful planning and must be designed into any scheme from an early stage.

One of the basic requirements for trees is the soil that they grow in. This may seem obvious but this is so often over looked or ignored, leading to poor growth and high plant failure rates. An old saying goes “plant a £100 tree into a £200 hole not a £200 tree into a £100 hole”. This highlights the need to get the planting medium right. The larger volume of soil available to the tree the more likely it will survive and the better it will flourish.

This also highlights the need to protect the soil that will be the planting area – there is no point in damaging a soil by compacting or contaminating it and then expect to get trees to grow well in it.

It is vital that all the organisations involved work together to make sure trees become established to ensure that money is well spent and that our towns and cities get sustainable planting solutions. This needn’t be expensive or difficult – it is just about good communication and getting the right advice at the right time.

Arboriculturists need to engage with their clients so that developers and organisations are fully aware of the benefits of planting and of having mature trees in our landscape. People involved in the tree industry have a duty to educate our clients to achieve an aim that is beneficial to us all. But they cannot work in isolation and LPA have a duty (literally) to apply the appropriate focus on not just tree planting but aftercare and maintenance.

Aspect Tree Consultancy launches with training seminar

Welcome to the first blog posting by Aspect Tree Consultancy Ltd.

The company launched in November 2008 and combines the talents and experience of Dominic Scanlon, Jon Kiely and Chris Widdicombe.

On 4th February 2009 we ran our first seminar – Tree Risk Management for Housing Associations. The company has a policy of providing training and advice that will provide a public benefit across the South-West of England and beyond. The seminar was run in conjunction with Tor Homes, South Hams District Council and QTRA Ltd. A major part of the Aspect ethos is to work in partnership with other organisations and companies to make a real impact on tree care.

The event was a real success with excellent feed back from the delegates. There is no doubt in our minds that we got a great response because we made every attempt to make the day relevant to peoples actual jobs.

Many Housing Associations originated from Local Authorities but when they split they lost all the specialists that Councils have the benefit of. As a result many people responsible for trees have no training or experience in managing tree populations or managing the risk that they can pose.

Our event aimed to give the delegates an overview of tree management and how they can achieve sensible and affordable tree management – to suit their budgets. Trees generally pose a low risk of harm and managing the risk they pose should be guided by the location they are in and how frequently this is used.

The event started with Dominic providing an over view of tree biology and how poor pruning can increase management costs over the long-term.  This was followed by Simon Putt from South Hams District  Council giving advice on tree protections and tree work application procedures.

Quantified Tree Risk Assessment – an affordable system:

We promote the Quantified Tree Risk Assessment system and we had the honour of the systems author, Mike Ellison, giving a talk about QTRA. This was followed by a presentation by Rob Scholefield of Tor Homes who gave a working example of how he uses the QTRA system and how he has implemented a tree policy to ensure that he is spending his money where it is really required.

The benefit of this system is that is allows tree owners to identify the sites or areas that are most frequently used and then to focus their tree inspections to the areas of the highest use. By prioritising in this way tree owners can prevent expenditure on unnecessary inspections or overly detailed ones. There is also a reduced tree surgery cost compared to the works thrown up by the traditional survey method.

QTRA and Health & Safety Executive Guidance:

The QTRA system corresponds to the current HSE guidance and promotes sensible and simple methods for inspecting and managing trees.

Upcoming Aspect Seminars:

Aspect will be running another seminar to deal with Planning Applications and 1APP – to highlight what information applicants need to include with a planning application and why.  The seminar will deal with best practice and advice on how to minimise problems at the application stage.  If you would like to attendend this then please contact us to register your interest.