Welcome to the LTOA website. The London Tree Officers Association (LTOA) constitutes the professional & technical voice for London's trees & woodlands. Its aim is to enhance the management of the Capital's trees.
We hope that you find the LTOA website both interesting & informative. If you have any questions, comments or suggestions, please do not hesitate to contact us.
The LTOA and Tree Officers have been involved with the control / eradication of Oak Processionary Moth (OPM) since it was first identified in London in 2006. In 2010 the LTOA published their Guidance Note on OPM.
The LTOA has worked closely with the Forestry Commission (FC) and its partners, engaged with the Advisory Group and maintained its own OPM Working Party. With the current programme review and the possibility of the ending or downgrading of FC control, the LTOA feels it is time to restate its views on the OPM issue.
The LTOA members who wrote this statement are: Richard Edwards (LB Croydon, LTOA Chair), Craig Ruddick (LB Richmond) and Dave Lofthouse (LB Merton, LTOA Executive Committee member).
Tree-lined routes across the terrestrial ecosystem connect urban and rural landscapes, roads and rivers, canals and railways which, when considered together, make up the linear forest. They conserve nature, clean the air, sequester carbon and promote health and wellbeing, right where we deliver pollutants. A novel appreciation of these integrating services equates to a new environmental discipline.
This seminar offers a dynamic exchange between European colleagues. On the Continent, an integrated approach to tree-lined routes and linear forests is being pioneered by a number of inspired initiatives including from Poland, Germany, France, the Czech Republic and others. Never before has this carefully crafted group of people met together to discuss this vital subject. Here is a rare opportunity to meet with experts in the field, brought together at this prestigious venue by Neville Fay, founder of the Treework Seminar Series. Forging common links points to a wider, cross-cultural, integrated model for disciplines to cross-pollinate and collaborate. Our seminar aims to unpick sectoral interests and compartmentalised thinking. By sharing information and knowledge about natural resources, carbon sequestration, pollutant removal, flood management, economic and tourism benefits and forest production-potential, we lay a new foundation for what constitutes the national and European linear forest for the 21st century.
Research from academics at Bangor University has suggested that avenues of trees on urban streets can damage the health of pedestrians by trapping air pollutants beneath their canopy. It warns that the effect could be so bad on streets with slow-moving traffic that councils should consider chopping down trees.
The above was the result of an item in ‘The Conversation’ which bears very little relation to any actual state of affairs in London - click here
A photo shows an avenue of trees, looking very much like a park. Clearly no vehicles are permitted. The avenue is lined with benches. The caption says ‘a tree canopy looks nice but where is the air pollution supposed to go’. What pollution? The fact of trees cleaning the air by deposition of pollution would suggest the opposite in this case – that the presence of trees would be keeping pollution out.
As a matter of fact the negative canyon effect is well known, the benefits of tree lined streets well documented, and the presence of such tree lined canyons in our built environment fairly rare – although, to be fair, the building bonanza in London is now creating canyons irrespective of the presence of trees. Tree Officers, in London as elsewhere, are aware of the need to take into account all aspects of what trees deliver – good and bad – and have done for years.
There is no new debate on this. The main failing of the contribution in ‘The Conversation’ is the very factor it purports to address – that of looking at one part of a highly complex equation in isolation. Tree Officers have for years dealt with the competing demand for shade and demands for light. We know that species such as the Birches may be the very best at capturing roadside particulates but may not be suitable for a host of other reasons. That Oaks and Willows produce VOCs. Willows are almost never and Oaks seldom planted in streets – but if you want rapid growth or rich bio-diversity, these are some of the trees you need.
The argument about trees trapping pollution at street level also ignores the temperature reductions gained in tree lined streets and strangely even ignores simultaneous removal of pollution by deposition – bizarrely leaving the impression that trees are responsible for pollution.
It is suggested that trees ‘are like walls or cars’ in preventing circulation of air. They are of course nothing of the sort. Almost any vegetation has some porosity and deposition on plant surfaces is known to be many times more ‘probable’ than on manufactured surfaces - concrete, glass and car bodywork.
It’s also true that tree officers in the UK have to consider the weather. Not simply the fact that our urban climate is becoming more and more like an arid Mediterranean one at times but also that the UK is one of the windiest corners of Europe. Practitioners such as our members would dearly love to see the ‘Canyon’ studies applied to conditions in July 2015 – seemingly one of the windiest summer months for years.
It is alleged that it is the job of ‘urban planners and local authorities to ensure trees are not just planted where they look nice’. It might be useful to recognise the fact that between 60 and 70% of our trees are in the private sector with fairly minimal governmental control – a last hint that when discussing the benefits and dis-benefits of trees its best to look at the whole picture and not focus on one little bit. After all, that’s what research is all about!
The role of the LTOA is to enhance the management of the Capital's trees & woodlands. The environmental, social, economic, health and wellbeing benefits of trees are well documented and we would like to ensure that a clearer picture is given which has been well researched and published.
We would draw your attention to a publication by the Woodland Trust and its references - Urban Air Quality Report (April 2012) prepared by Mike Townsend of the Woodland Trust with the assistance of Dr Tom Pugh and Professor Nick Hewitt, both of Lancaster University, and Professor Rob MacKenzie of the University of Birmingham - click here
The above article is the full response given to Horticulture Week and used in their article 'Report suggests large -canopied street trees can exacerbate pollution', 21 August 2015, http://www.hortweek.com/report-suggests-large-canopied-street-trees-exacerbate-pollution/landscape/article/1360654.
Written by Dave Lofthouse on behalf of the London Tree Officers Association
Dip. Arb. (RFS) M.Arbor.A.
Arboricultural Manager, Greenspaces
London Borough of Merton
A dozen or so members assembled at the Thames Chase information centre for what proved to be an informative and inspiring day. In an introductory session indoors we were fortunate to have Jim Lyon, Forestry Management Director for the East of England, to give us an overview of the vision behind the creation of the park, and how it had been sustained, despite the catastrophic changes to local authority finances, through the creation of the Thames Chase Trust and with support from the Forestry Commission. This was followed by a more detailed look at the running of the park and the use made of it from Jenny Austin, the Trust Manager.
Before lunch in the café we were then taken on a short walk. What made the greatest impression here was the sheer number of visitors using the area, clearly enjoying their days out, and how the dense forestry style planting had created a new landscape on what had been an entirely open site before its restoration.
In the afternoon we were taken a little further afield to see a couple of nearby restoration projects with Yianni Andrews and Jenny Austin, one on the edge of the built up area, and with substantial investment to increase its capacity for recreational use, and another site which was more simply and economically designed and planted. We were able to see the progress in the design of the woodland blocks, and also the impact of the degree of restoration of the land on tree growth.
It was an excellent day useful not so much for specific lessons to be taken away on the style of planting etc., but memorable for the determination of those involved to put a vision into practice, and not to allow that vision to be abandoned. It was particularly interesting to hear the thoughts of Jim Lyon, and we are indebted to his friendship with Richard Edwards that he found time for us.
Principal Officer - Trees & Landscape Strategy - Epping Forest District Council