AN AXE TO GRIND. MTOA’s QUARTERLY MAGAZINE

New look Axe, Autumn 2014 Edition.

Interactive content; where you see the leaf logo then the page is ”live” so click for any internet content, try it

Meet this edition’s contributors

If you click on any of the pictures you can read their on-line biography. Where you see “Feature Article” the piece is unique to the Axe!

Ian McDermott

Editor

If you are reading this edition of the Axe on PDF then please ensure you have the view option set for a two page spread, it is designed for on-line

viewing so make use of the links embedded.

The MTOA is a fully constituted not for profit organisation . The views expressed in the magazine may not reflect the official views of the MTOA

and the association accepts no liability for any views or technical advice presented by its contributing authors.

Jeremy Barrell Francesco Ferrini Gareth Hare Richard Nicholson

Chris Parker Glynn Percival Kenton Rogers Moray Simpson

Interactive content; where you see the leaf logo then the page is ”live” so click for any internet content, try it

Moray Simpson, Chairman's stump. 4

Francesco Ferrini, Air Temperatures 14

Jeremy Barrell, Insights for Tree Risk Managers 20

Glynn Percival , Potential Pest and Disease Threats 28

Kenton Rogers, Urban Forest Management 36

Chris Parker, Beech Woodwart 46

Gareth Hare, Yellow Birch. 48

Richard Nicholson, Big Belly Oak 52

And finally, Editors last word 61

Inside this issue:

Features

Please don’t forget to visit the MTOA’s sponsors too.

Upcoming

Events.

September

MTOA Tree Health

AA Conference

APF

October

NHS Forest Confer-

ence

ISA Conference

ATF study tour

November

SMA Conference

December

MTOA AGM

Please submit your

calendar dates to the

Editor

MTOA Chairman, Moray Simpson.

I n recent weeks we have being enjoying the fine summer weather, but at

times the summer heat has been quite uncomfortable, well at least for

me as a Scotsman, it has. I’ve welcomed the shade provided by trees in the

town where I work and in streets where there are no trees, I have sought

shade from buildings. I do not like extreme heat and have no desire to be

sunburnt and end up with skin cancer or cataracts, both by-products of being

exposed to too much sunlight. Buildings by there shear size do provide

welcome shade, but largely, trees are much nicer to look at and also built

structures don’t ameliorate local climates by evapotranspiration.

In the midst of the recent heatwave, I was thinking about what to write for

the “Axe” and I couldn’t decide. Probably, because I find it hard to think when

I’m getting frazzled by the sun and the heat is pointing my mind in one

direction only; where can I get a cold beer from! So when an MTOA

colleague, Portia Howe, passed on a link to the government’s “Heatwave Plan

for England 2014”, I thought that’s topical. So my article is about trees being

part of the solution to the ill effects that extreme summer temperatures have

on our health.

I strongly believe that people’s health and wellbeing is inexorably linked to

the health and wellbeing of our urban forests. Healthy urban forests =

healthier humans. In relation to high summer temperatures and the

detrimental effects that this can have on human health, it is imperative that

urban forestry is recognised by Local Health boards as a means to preventing

human health problems and mortality. Local Authorities should be planting

Front cover picture. Lirioden-

dron tulipifera, that this

year have been magnificent

but please see the article on

page 14!

Picture courtesy of Karan A.

Rawlins, University of Geor-

gia.

The Chairman’s Stump.

trees and managing our existing trees to

provide shade in public spaces and school

grounds and we should be planting and

protecting existing trees to help reduce air

pollution and the urban heat island. We also

have to bear in mind that climate change will

make matters much worse.

According to the latest UK Climate

Projections, UKCP09, the UK will experience

hotter and drier summers and more very hot

days. In fact, the UK Government’s

Supplementary Green Book “Accounting for

the Effects of Climate Change” predicts that

there will be more frequent periods of

temperatures exceeding 35°C and because

the effects of excessive heat on health can be

severe (including death), the Department of

Health has introduced an annual Heatwave

Plan to ensure the country is prepared for

future heatwaves. This supplementary “Green

Book” guidance recommends long-term

planning to adapt and reduce the impacts of

climate change (HM Treasurer/ DEFRA, 2009).

The “Green Book”, along with the “Orange”

and “Magenta” books, is the UK government’s

guidance for the appraisal and evaluation of

policies, programmes and projects. Climate

change means heatwaves. (HM Treasurer/

DEFRA, 2009).

The English “Heatwave Plan” (there is a Welsh

Heatwave Plan, but not sure if there is a

Scottish plan) recommends long-term

planning to adapt and reduce the impacts of

climate change. This is another reason for

tree and urban forestry strategies to plan for

the long-term, rather than is still all too

common, the short-term.

Outdoor air pollution causes 35,000 – 50,000

premature deaths per year In the UK

(Environmental Audit Committee, 2010). Air

pollution causes annual health costs of

roughly £15 billion to UK citizens (DEFRA,

2010). There was a major heatwave across

much of Europe in the first two weeks of

August 2003, during which temperatures

peaked at a new record of 38.5° C in the UK.

The UK Office for National Statistics have

reported an excess of 2045 deaths in

England and Wales for the period from the 4th

to 13th

August 2003 above the 1998-2002

average for this time of year. Previous studies

have suggested that a significant proportion

of the excess deaths during heatwave

conditions can be associated with the

elevated concentrations of air pollutants

(Continued on page 6)

rather than a direct effect of high

temperatures (Stedman, J. R. 2004).

Trees remove air pollution by the interception

of particulate matter on plant surfaces and

the gaseous pollutants through the leaf

stomata. Trees affect air quality through the

direct removal of air pollutants, altering local

microclimates and building energy use, and

through emission of volatile organic

compounds (VOCs), which can contribute to

O3

and PM2.5

formation (Nowak et all, 2014).

Air pollutants which are harmful to human

health are nitrogen dioxide (No2

), Ozone,

sulphur dioxide and small size particulate

matter (PM10

), all of which cause and

exacerbate pulmonary and cardiac diseases

(Department of Health, 1998 & Pope, C. A.

2004). So, increasing our urban tree

populations, paying particular attention to

species we’re planting, so we do not have too

high a percentage of VOC emitting species,

will help reduce air pollution.

Trees change summer urban micro-climates

for the better by creating shade and allowing

cooler air to accumulate and circulate at

ground level. Planting trees and vegetation

and the creation of green spaces to enhance

evaporation and shading are other options, as

temperatures in and around green spaces can

be several degrees lower than their

surroundings.

Trees also help to reduce the air temperature

by the cooling effect of evaporation. Trees

‘transpire’ water, releasing large amounts of

moisture into the air. One large tree can

release 200 to 300 gallons of water on a

summer day. Studies suggest that air-

conditioning demand can be reduced by up to

30 per cent through the effects of well-placed

trees. There is considerable evidence to

support the case for well-designed green

infrastructure: trees, parks, green roofs, and

ponds/lakes can all help to reduce heat

retention. (Public Health England, 2014).

In summary, urban green space and trees can

have the following beneficial effects:

· reduces urban heat islands – predictions

for urban temperatures over the next 70

years show that if there is less than 10 per

cent urban green cover, urban

temperatures will increase by about 8.2°C,

whilst if green cover exceeds 10 per cent

it will keep temperatures to only 1°C above

current temperatures;

· reduces pollution – each year 1.3 million

trees would remove 2,535 tonnes of

pollutants from the air (Public Health

England, 2014).

So who’s at risk from extreme summer

temperatures? Well, Public Health England

states that anyone living in urban areas is at

risk, with those over the age of 75 and young

children and babies being categorised as high

risk groups (Public Health England, 2014*).

The “Heatwave Plan for England” recommends

that commissioners of health and social care

and local authority Directors of Public Health

undertake long term planning to prepare for,

and mitigate, the impact of heatwaves. So

what’s the relevance of this to municipal

arboriculturists and urban foresters? Well, The

English Heatwave Plan recommends that, as

part of the aforementioned long term

planning, environmental action be undertaken

to mitigate against the detrimental affects of

heatwaves on health; i.e. that trees and green

spaces are increased (Public Health England,

2014*).

Research by Lancaster University indicates

that if the number of trees is doubled by

planting up all possible sites in the study area

(West Midlands) particulate air pollution could

be reduced by 25%. This could lead to a

reduction of 140 deaths each year in the

study area (Centre for Ecology & Hydrology/

Lancaster University).

(Continued from page 5)

Looking closer to home, well where I work,

Wrexham County Borough, we have figures

from the 2014 Wrexham I-tree eco study for

the amount of air pollution removed by our

urban trees and how much money this saves

in health damage costs. Wrexham’s urban

trees remove 60 tonnes of air pollution,

including NO2

, ozone, SO2

, CO and PM10

and

PM2.5

each year, which equates to a saving of

more than £650,000.Ozone showed the

greatest reduction by urban trees,

demonstrating that although trees can

increase ozone levels by producing VOC’s,

they remove far more than they produce

(Rumble, 2014).

To finish off, here’s some more relevant facts

taken from Centre for Ecology & Hydrology/

Lancaster University document “Trees &

Sustainable Urban Air Quality: Using Trees to

Improve Air Quality in Cities” report.

· Trees benefit human health.

· Trees positively affect air quality.

· Trees provide shade & humidity.

Mature mixed woodland captures airborne

particles at approximately three times the

rate of grassland. The proportion of available

area planted with trees has a direct affect on

the resultant reductions in particle

concentrations (see figure 1).

Trees remove airborne pollutants at three

times the rate of grassland. Trees at the edge

of woodland are more effective at removing

atmospheric pollutants than trees in the

centre of woodland. This is due to both larger

leaf areas and greater exposure to wind.

Overall, the effects on air quality of very large

scale planting of almost all tree species in

urban areas would be positive (Centre for

Ecology & Hydrology/ Lancaster University).

(Continued on page 8)

Figure 1. Table showing that increase in planted land leads to decrease in particulate pollution.

References

Centre for Ecology & Hydrology/ Lancaster

University. Trees & Sustainable Urban Air

Quality: Using Trees to Improve Air Quality in

Cities.

http://www.es.lancs.ac.uk/people/cnh/

UrbanTreesBrochure.pdf

Department of Health. Committee on the

Medical Effects of Air Pollutants:

Quantification of the Effects of Air Pollution

on Health in the United Kingdom. The

Stationery Office; London, 1998.

http://

webarchive.nationalarchives.gov.uk/2014050

5104658/http://www.comeap.org.uk/

documents/reports

Environmental Audit Committee. Fifth Report:

Air Quality; The Stationery Office, London

2010.

http://www.publications.parliament.uk/pa/

cm/cmenvaud.htm

HM Treasurer/ DEFRA. Accounting for the

Effects of Climate Change. Supplementary

Green Book Guidance, June 2009.

https://www.gov.uk/government/uploads/

system/uploads/attachment_data/

file/191501/

Accounting_for_the_effects_of_climate_chang

e.pdf

Nowak, D.J. et all. Tree and Forest Effects on

Air Quality and Human Health in the United

States. Environmental Pollution 193, 2014,

Pages 119-129.

http://www.fs.fed.us/nrs/pubs/jrnl/2014/

nrs_2014_nowak_001.pdf

Pope, C. A., et all. Cardiovascular Mortality

and Long-Term Exposure to Particulate Air

Pollution. Circulation 2004.

http://circ.ahajournals.org/

content/109/1/71.full

Public Health England. Heatwave Plan for

England – Making the Case: the impact of

heat on health – now and in the future. Public

Health England & NHS England. May 2014.

https://www.gov.uk/government/

publications/heatwave-plan-for-england

Public Health England. Heatwave Plan for

England – Protecting health and reducing

harm from severe heat and heatwaves. Public

Health England & NHS England. May 2014*.

https://www.gov.uk/government/

publications/heatwave-plan-for-england

Rumble, H. et all. Valuing Wrexham’s Urban

Forest – Assessing the Ecosystem Services of

Wrexham’s Urban Trees: A Technical Report.

Forest Research/ Treeco2

nomics, June 2014.

Stedman, J. R. The Predicted Number of Air

Pollution Related Deaths in the UK during the

August 2003 Heatwave. Atmospheric

Environment Volume 38, Issue 8, March 2004,

Pages 1087–1090.

http://www.sciencedirect.com/science/

article/pii/S1352231003010203

DEFRA. Air Pollution: Action in a Changing

Climate. DEFRA Publications. March 2010.

https://www.gov.uk/government/uploads/

system/uploads/attachment_data/file/69340/

pb13378-air-pollution.pdf

Moray Simpson MTOA Chair.

(Editor’s note; please also see the article on

page 14.)

(Continued from page 7)

http://www.mtoa.co.uk/

W e are pleased to announce the

foundation of the Hellenic

Association for Arboriculture

(HAA).

The foundation of the HAA was the fruit of

our efforts for synergy and interdisciplinary

approach in the field of Arboriculture in

Greece, which started with an open-call

discussion in late 2012.

Its 20 founding members include people

from a broad range of disciplines (arborists,

agriculturists, foresters, landscape architects)

coming from both public and private sector

backgrounds. The association is based in

Athens and its goals, as stated in its Charter,

are:

The promotion of Arboriculture in Greece,

with regards to the protection,

conservation, management, and care of

(mainly) urban trees.

The development and dissemination of

knowledge and the raising of

consciousness regarding modern

practices in Arboriculture.

The conduct and support of activities

relevant to the protection of (mainly)

urban trees in Greece and the

participation in similar activities abroad.

The promotion of actions that aim to the

protection and conservation of (mainly)

urban trees.

The creation of a collaboration and

information network for the provision of

technical and scientific assistance to

initiatives of both local and national scale,

along with the establishment of

infrastructure towards the fulfilment of

the aforementioned goals.

The collaboration with associations and

organizations of similar scopes in both

Greece and abroad along with the

representation of Greece, with member

status, in the European Arboricultural

Council (EAC), a similar organization

based in Germany.

The utilization of all potential resources,

being from national, municipal, European,

or other authorities, for the

implementation of projects that are

consistent with the aforementioned

activities, such as the conservation of

urban trees through Arboriculture and

ultimately the protection of the urban

environment.

The Association has been legally recognized

with the 5/02–04–2013 court order of the

Athens County Court, and has received the

registration number 29524 in the Book of

Associations of the Court of First Instance of

Athens.

Anyone over 18 years old with an active

interest in Arboriculture in Greece can

become a member of the Association. You

can communicate with the Association via:

info@dendrokomia.gr.

Minas Tsakiridis

President, HAA.

HELLENIC ASSOCIATION FOR

ARBORICULTURE

Revised Planning Practice Guidance. When preparing Local Plans and taking planning decisions local planning authorities should pay

particular attention to integrating adaptation and mitigation approaches and looking for 'win-

win' solutions that will support sustainable development. This could be achieved in a variety of

ways, for example:

· by maximising summer cooling through natural ventilation in buildings and avoiding solar

gain;

· through district heating networks that include tri-generation (combined cooling, heat and

power); or

· through the provision of multi-functional green infrastructure, which can reduce

urban heat islands, manage flooding and help species adapt to climate change – as

well as contributing to a pleasant environment which encourages people to walk and

cycle.

Local planning authorities should be aware of and avoid the risk of maladaptation (adaptation

that could become more harmful than helpful). For example, designing buildings to maximise

solar gain in winter without thinking through the implications for overheating in summer.

Sustainability appraisal and, where required, Environmental Impact Assessment, can be a useful

for testing the integration of mitigation and adaptation measures and the long term implications

of decisions

Let it not be said that a belt

and bracers approach was

not tried here.

A memorial Oak planted for a

deceased student in the Ar-

boretum of a very well known

and respected land based

college is pictured. It has a

total of three full stakes, six

ties with poorly placed spac-

ers and a cane that is wired

to the stem “just in case” or

maybe it’s just left on from

the nursery.

It has long been a bug bear

of mine that the quality of

tree planting is generally in

the UK simply awful. This

season alone has seen over

forty trees in the streets of

Walsall alone snapped off at

the top of the (single low)

stake after the council went

back to its old ways of plant-

ing using unskilled staff,

heart-breaking for everyone

and entirely avoidable.

However, given that we are

now doing this on the college

grounds in front of arboricul-

ture students then this will

be the approach with our in-

coming young arborists.

I fear the situation will never

improve.

Comments?

The Axe hits around the World. The Axe continues to

grow and just in the

last month (July 2014)

saw the Summer 2014

edition go over 1000

readers and hit quite a

variety of countries as

can be seen from the

screenshot (left).

As expected we are big

in the USA but it is

both surprising and

welcome that we have

readers in Uganda and

Kenya!

Contributions are wel-

come and keep shar-

ing!

S ome of the most severe impacts of

climate change may result from an

increase in the frequency and

intensity of extreme climate events, rather

than from gradual changes in mean

conditions. Drought, in particular, is likely to

become more common in many areas due to

increasing temperatures and shifting

precipitation as reported by William et al.

(2011) especially when it will be associated

by high temperatures.

As stated by Nardini et al., (2013), “according

to current understanding, three potential

mechanisms can explain drought-induced

tree desiccation and death: hydraulic failure

(resulting from cavitation-induced embolism);

carbon starvation (resulting from depletion of

carbohydrate reserves during prolonged

stomatal closure); biotic agents attack

resulting from climate-driven outbreaks of

insects and pathogens. These mechanisms

are not necessarily mutually exclusive. In

fact, embolism-avoidance mechanisms or

hydraulic failure per se might cause stomatal

closure, leading to reduced photosynthetic

rate and carbon starvation. In turn, carbon

starvation and related impairment of phloem

functioning might inhibit mechanisms

responsible for refilling of embolized

conduits or ion-mediated compensation of

embolism- induced drop of xylem hydraulic

conductance, thus exacerbating the drought-

induced reduction of water transport

capacity. Finally, carbon starvation might

reduce the production of metabolites

involved in plant defence strategies, thus

favouring attacks by biotic agents which may

lead to further xylem blockage” (see below).

As for the temperature trees and shrubs

generally have optimum growing conditions

across the range of temperatures from 20°C

to 30°C. It is known that tree physiology can

be negatively affected by hot temperatures

(as mentioned especially if matched with

drought) which can injure and kill living plant

systems (i.e. deciduous trees very frequent

show curling, bending, rolling, mottling,

marginal browning (scorching), chlorosis,

Air temperature, and its effect on tree physiology and on tree pests under climate change

shedding and early autumn coloration of

leaves, in response to hot temperature,

drought and high irradiance). Under

environmental condition in which water

availability may limit growth, abnormally high

temperatures can alter normal energy flows

and can increase both respiration and

transpiration.

However, trees can dissipate tremendous

heat loads if allowed to function normally.

Unfortunately, hot temperatures greatly

increase the water vapour pressure deficit

(VPD)(dryness of the air) which cause leaf

stomata to close because of rapid water loss

and limits transpirational cooling. When

transpiration is limited by hot temperatures,

plant tissue temperatures can rise above the

thermal death threshold. According to what

found in the literature we can state that a

thermal death threshold is reached at

approximately 45°C though it varies

depending upon the duration of hot

temperatures, the absolute highest

temperature reached, tissue age, thermal

mass, water content of tissue, and ability of

the plant to make adjustments to

temperature changes (for example in species

with a large chilling requirement, milder

winters might result in inadequate chilling

and hence delayed and erratic bud burst in

spring).

(Continued on page 16)

Urban trees with leaf withering due to drought stress

The main statement is that a tree must

always be in equilibrium with its

environment. Any time this equilibrium is

altered, the tree is stressed and must spend

extra energy to survive. Trees can only react

to their environment in genetically pre-set

ways. Due to the climate warming this

equilibrium is always more frequently altered

and temperature rising due to global change

is widely predicted to profoundly affect trees

by altering photosynthesis and respiration,

soil organic matter decomposition and

mineralisation, phenology and frost

hardiness, species distributional changes,

and adaptation and evolution.

Also, higher temperature may indirectly

affect the expansion range and the damages

of several insect species, as well as changes

in seasonal phenology. Based on some

models and on some references in the most

recent literature is highly probable that

insects will have the potential to be a major

problem for urban trees under climate

change. As reported in specific research it is

extremely difficult to predict with any

confidence the impact of climate change on

insect pests, but it seems ascertained that

their distributions will change. Impacts on

urban tree species are also uncertain, as

much of current scientific work in this area

has focused on forests species. The impact

of facultative pathogens such as sooty bark

disease of sycamore (Cryptostroma corticale)

may worsen, while some insect pests that are

present at low levels, or currently not

considered important, may become more

prevalent. Examples of the latter include

(Continued from page 15)

Species selection is fundamental when planting in warm climates. In this case a Tulip tree

shows more leaf wilting and dieback compared to the more tolerant Small-leaved Lin-

den tree

defoliating moths and bark beetles. Some

authors described since early 60’s the

potential for the incidence, severity and

northern ranges of disease to increase

should climate factors, which normally act as

constraints against outbreaks, become

altered. Others predicted an increase in tree

injury and death from insects and pathogens,

acting as a single agents resulting from a

warmer and drier climate.

Predicting future pest and pathogen trends is

difficult because of the fine balance between

pest/pathogen, the health of the host tree

species, and any natural defence

mechanisms/pest predators. However,

stressed trees are more susceptible to insect

pests and diseases, and many insect pests

are likely to benefit from climate change as a

result of increased breeding activity and

reduced winter mortality. Further, an increase

of temperature may alter the mechanism by

which the insects adjust their cycles to the

local climate, resulting in faster development

and higher feeding rate or in changed

feeding attitudes. In addition, exotic insect

species may be able to persist and become

sometimes catastrophic under warmer

temperatures where they might previously

have been controlled by colder temperatures.

The introduction and establishment of such

exotic species such as the Asian longhorned

beetle (Anoplophora glabripennis and A.

chinensis) and the emerald ash borer (Agrilus

planipennis) also in Europe may be easier and

more likely under warmer climatic conditions.

Drought has been shown to increase insect

feeding activity due to increased

concentrations of carbohydrates in foliage

under dry conditions. Climatic conditions

also affect the virulence and the number of

generations of other insects like

horsechestnut leaf miner (Cameraria

ohridella) or can extend to the northern

latitudes some parasites typically present in

the warmer climate where they have natural

enemies (es. Rynchophorus ferrugineus on

palm trees, a dreadful insect which has

changed the typical landscape all over the

Mediterranean countries by killing hundreds

of thousands Canary palms and now also

feeding on other palms).

Also an increasing number of studies have

reported on shifts in timing and length of the

growing season, based on phenological,

satellite and climatological studies. This can

alter the physiology of trees and interact with

the dormancy mechanisms. We know that

trees are able to survive the cold winters

after sequential physiological events, leading

to build up of dormancy and cold resistance.

These processes are normally initiated by

environmental signals from decreasing

photoperiod and temperatures. After the

establishment of dormancy, low

temperatures are necessary to break the

physiological dormancy. The sum of chilling

temperatures needed for the break of winter

dormancy varies for different species and

ecotypes. After chilling needs are fulfilled,

bud break will happen when temperatures

are high enough. This will result in changes

in phenophases mainly consisting in

advances of the spring phenophases and

delay in the autumn phenophases and it is to

be underlined that climate changes may

cause uncertain ecological consequences,

with implications for ecosystem stability and

function in urban environment.

The added effects of warming due to the city

structures and the general climatic change

may give a rather large increase in

temperatures in cities. If the higher

temperatures initiate the trees to decrease

the tolerance to low temperatures, the trees

may be more susceptible to damages from

spells of spring frost.

Urban tree management must meet these

challenges and the role of research must be

(Continued on page 18)

promoted and funded. Increased emphasis

should be placed on selection and/or

breeding trees for environmental stress

tolerance, such as drought and temperature

stress. Tolerance or resistance of trees to

environmental stress will result in healthier

trees that are not only able to resist disease,

but will notably improving the quality of the

urban environment.

It is our opinion that the main strategy for

protecting trees from the adverse effects of

climate change and for maximizing their

benefits on the urban environment and on

human well-being, consists in developing

long term management and replacement

programmes which will ensure a balanced

age range and a good tree health.

Francesco Ferrini

D e p a r t m e n t o f

Agrifood Production

and Environmental

Sciences – University

of Florence (Italy)

Citations

1. William. A. H., R. M. Marchin, P. Abit, ON

L E E L., 2011. Hydraulic failure and tree

dieback are associated with high wood

density in a temperate forest under

extreme drought. Global Change Biology

17, 2731–2742, doi: 10.1111/j.1365-

2486.2011.02401.x

2. Nardini A., M. Battistuzzo and T. Savi,

2013. Shoot desiccation and hydraulic

failure in temperate woody angiosperms

during an extreme summer drought. New

Phytologist 200: 322–329 doi: 10.1111/

nph.12288

4. Bussotti F., F. Ferrini, M. Pollastrini, A.

Fini, 2014. The challenge of

Mediterranean sclerophyllous vegetation

under climate change: from acclimation

to adaption. Environmental and

Experimental Botany. Vol. 103: 80–98.

5. Chmielewski F.M., Rötzer T., 2001.

Response of tree phenology to climate

change across Europe., Agr. For.

Meteorol., 108:101-112.

6. Cleland E.E., Chuine I., Menzel A., Mooney

H.A., Schwartz M.D., 2007. Shifting plant

phenology in response to global change.

Trends in ecology and evolution, 22(7):

7. Cooke J.E.K., Eriksson M.E., & Junttila O.,

2012. The dynamic nature of bud

dormancy in trees: environmental control

and molecular mechanisms. Plant, Cell

and Envir., 35:1707-1728.

8. Hänninen H., Tanino K., 2011. Tree

seasonability in a warming climate.

Trends in Plant Science, 16(9):412-416.

9. Körner C., Basler D., 2010. Phenology

under global warming. Science, 327:1461

-1462.

10. Linderholm H.W., 2006. Growing season

changes in the last century. Agric. For.

Meteor., 137:1-14.

11. Lu P., Yu Q., Liu J., Lee X., 2006. Advance

of tree-flowering dates in response to

urban climate change. Agric. For. Meteor.,

138:120-131

12. Menzel A., et al., 2006. European

phenological response to climate change

matches the warming pattern. Global

Change Biol. , 12:1969-1976.

13. Mimet A., Pellissier v., Quénol H.,

Aguejdad, Dubreuil V., Rozé F., 2009.

Urbanisation induces early flowering:

evidence from Platanus acerifolia and

Prunus cerasus. Int. J. Biometeorol.,

53:287-298.

14. Way D.A., 2011. Tree phenology

responses to warming: spring forward,

fall back. Tree Physiol., 31:469-471.

(Continued from page 17)

D o you remember the front cover of the last

edition of the Axe? Well in case you can’t

it’s reproduced on the left. It featured a collapsed

rotten Lombardi after the February storms that had

fallen across some play equipment in the local park.

The top picture features a new installation of equip-

ment. The trees in the foreground is a 20m Acer

pseudoplatanus and yes, that is a large wound at the

point where the trunk bends slightly over the new

equipment.

As an organisation we have struggled for many years

to engage fully with Landscape Architects and Park

Managers and we continue to do so despite offering

genuine good value CPD in all area’s of tree manage-

ment and maintenance.

As long as the above decisions are still being made

to install a high value fixed target in the fall zone of

a tree with a clear defect then the work of the MTOA

must continue to strive to educate and engage with

those colleagues who clearly need our expertise.

See the article overleaf if you need more convincing.

—one of the reasons we exist.

Legal judgments relating to tree

failures

Much of my work as a consultant focuses on

advising duty holders on how to manage

their trees so that, in the event of an incident

where harm arises, they are in a strong

position to defend allegations of negligence.

Whether you are a tree officer, with direct

responsibility for tree safety, or a consultant

acting as an advisor, obvious issues of

concern to duty holders include: 1) do their

trees need inspecting at all and, if so, how

often; 2) what sort of inspection is

necessary; and 3) what credentials should an

inspector have to undertake the task? You

can find out more about answering these

questions in this paper, Balancing tree

benefits against tree security: The duty

holder's dilemma (Arboricultural Journal,

Volume 34, Issue 1, 2012), that can be

downloaded at www.tandfonline.com/action/

showMostReadArticles?

journalCode=tarb20#.U9N_TmdOVLi.

In that paper, I explain that legal judgments,

in tandem with many other considerations,

can offer some value through insights into

how the courts view specific issues.

However, such cases are few and far between

in the tree world, with only nine published in

the last decade. Furthermore, each of those

cases only deals with a limited number of

very narrow issues specific to each set of

circumstances, which often limits the

potential for meaningful interpretations.

Finally, the reliability of those interpretations

is further diluted because significant legal

weight is only given to cases that go to

appeal to become authorities, with

Micklewright -v- Surrey County Council being

the only case out of the nine to achieve that

status.

More about inquests

At the time of writing that paper, I had little

experience of acting as an expert witness at

inquests, and so did not include them in my

analysis. However, more recently, there have

been a number of inquests relating to deaths

from falling branches, which may be of

interest to tree managers, with two so far in

2014 (see below). In general terms, an

inquest is a fact-finding enquiry to establish

who has died, and how, when and where the

death occurred (www.judiciary.gov.uk). It is

a form of public enquiry to determine the

truth and is intended to be inquisitorial. This

is a different thrust from the adversarial

S o far, 2014 has been a busy year for legal judgments and inquests resulting from

harm that has arisen from tree failures. In this article, Jeremy Barrell references

three that he has been involved in, drawing out practical aspects that he thinks

may be of value to arboriculturists, managers and duty holders charged with

managing the risk from trees. Jeremy offers this selection of observations from his

perspective as an arboriculturist and they should not be taken in any way to be a definitive

analysis of the law, which is beyond his expertise to provide.

approach adopted in criminal and civil trials.

Furthermore, the inquest verdict cannot be

framed in such a way as to appear to

determine matters of criminal or civil liability.

Through the Coroners and Justice Act 2009,

coroners now have a statutory duty (as

opposed to a previous discretion) to issue a

report to any person or organisation where

the coroner believes that action should be

taken to prevent future deaths. These are

called prevention of future deaths (“PFD”)

reports and it is the stated intention of the

Chief Coroner that they encourage change

for the better. There is a presumption in

favour of publication and as many as

possible are publicised on the judiciary

website. These are deemed to be important

instruments of change and they can be

applied to deaths associated with tree

failures. From a review of the published PFD

reports, I have not discovered any so far that

have been issued relating to tree failures, but

the indications are that is soon about to

change!

Inquest into the death of Michael

Arthur Warren on 5th October

2012

This Inquest was heard in front of Mr Peter

Bedford, the Senior Coroner for Berkshire,

and lasted for three days, from 8–10 July

2014, at Windsor Guild Hall. Three tree

expert witnesses were called; Dr Frank Hope

appeared on behalf of Bracknell Forest

Borough Council, Mr Henry Girling appeared

on behalf of Mr Warren’s family and I was

instructed by the Coroner. Horticulture Week

reliably reported on this, with a short

overview of the case available at

m.hortweek.com/inquest-report-expected-

wider-national-interest/arboriculture/

article/1304974.

The incident was caused by the sudden

failure of a large and severely unbalanced

branch overhanging the road that fell and hit

Mr Warren’s car. There was significant

internal decay near the point of failure, which

lay behind a large pruning wound that had

fully occluded, hiding the decay. After

hearing all the evidence, the Coroner issued

a Narrative Verdict that concluded:

“The combination of visual signs was

sufficient to have caused the landowner, his

agent or a Highway Inspector to request a

more detailed inspection of the oak tree by

qualified Tree Officers. Such an inspection,

on the balance of probabilities, would have

identified the unbalanced nature of the

branch and the large occluded wound which,

in turn, would have led to more detailed

examination. This, in turn, would have

resulted in intervention works to the oak tree

significantly reducing the risk of the branch

falling as it did on 5th October 2012.”

The Coroner also advised that he would be

sending a PFD Report to Bracknell Forest

District Council relating to the training of

inspectors checking trees and the manner in

which drive-by inspections are carried out.

This PFD Report is not yet publicly available

and so its detailed content still remains

unknown. However, due to the scale of

highway inspections around the UK that have

to include trees, it is likely to be of national

interest once it is available.

This incident reflects my accumulating

experience that severe imbalance of large

branches or whole trees, in combination with

other weakening conditions, is regularly

associated with failures that cause harm. My

observations indicate that where the

imbalance really is severe, i.e. it looks

obviously wrong, and there are other

potentially weakening conditions, e.g.

declining health or structural defects,

inspectors should be vigilant when assessing

the potential for failure. This particularly

applies to large old wounds on mature trees

that have fully occluded, because the lack of

any external signs of decay can be taken to

imply that there is no significant weakness.

That may well be the case on young trees

that are growing rapidly and have

compensated for any weakness. However,

older trees growing more slowly may not be

able to put on sufficient reaction wood to

adequately compensate against the inevitable

decay that arises from the wounding, which

may result in a gradual weakening over time.

There is no automatic implication that large

occluded wounds on mature trees are always

a problem, but my observations suggest that

they should be carefully considered when

assessing the potential for failure.

Inquest into the death of Erena Wilson at

the Royal Botanic Gardens Kew (“RBGK”),

on 23 September 2012

This Inquest was heard in front of a Jury and

lasted for three days, from 11–13 June 2014.

In addition to evidence provided by RBGK, Dr

David Lonsdale provided expert evidence on

behalf of the Assistant Coroner and I

appeared as the expert witness instructed by

Erena Wilson’s family. Horticulture Week

responsibly reported on a daily basis as the

Inquest proceeded, and these updates can be

reviewed at:

· m.hortweek.com/inquest-hears-evidence-

death-2012-erena-wilson-hit-falling-

branch-rbg-kew/article/1298465

· m.hortweek.com/second-day-inquest-

2012-death-kew-erena-wilson-hit-falling-

branch-hears-further-evidence/

article/1298662

· m.hortweek.com/death-kew-visitor-hit-

branch-accidental-inquest-finds/

article/1299047

One of the main issues explored at the

hearing was whether the branch failure was

due to Summer Branch Drop, a loosely

defined condition used to group branch

failure events that occur on mature trees

during the summer with no obvious cause.

RBGK asserted that the cause of the failure

was due to a combination of wind and rain;

Dr Lonsdale thought the cause was

something “akin” to Summer Branch Drop;

my view was that it was Summer Branch Drop

because it exhibited more than enough of

the characteristics commonly associated with

such events. After hearing all the evidence,

and after less than an hour of deliberation,

the Jury returned a verdict of accidental

death, stating that “there is insufficient

evidence to establish the cause of the branch

failure”. As reported by Horticulture Week,

the Inquest also heard evidence about the

nature of the tree management regime in

place at the time of the accident, but the

finding of insufficient evidence to establish

the cause of failure meant that the Jury did

not have to comment on these management

issues.

Subsequently, Horticulture Week wrote two

further articles that can be reviewed at:

· m.hortweek.com/kew-death-2012-

accident-inquest-rules/article/1300552

· m.hortweek.com/summer-branch-drop-

warnings-wanted/arboriculture/

article/1304973

Again, these provide a balanced analysis, but

I add a short clarification on the following

statement within the most recent, “However,

a jury found that the death was an accident

with summer branch drop not the cause, and

Kew was not at fault”. This seems slightly at

odds with the Jury’s verdict: “there is

insufficient evidence to establish the cause of

the branch failure”. My interpretation of the

verdict is that the Jury could not establish the

cause, which does not rule out Summer

Branch Drop, as implied in the article.

Despite the Assistant Coroner’s expert and

myself aligned on the point that the cause

was something “akin” to Summer Branch

Drop, with me being more confident that it

was Summer Branch Drop, the Jury were not

convinced and hence the specific wording of

the verdict.

During the lengthy preparation for this case, I

worked closely with Mr Wilson and his legal

team, researching previous incidents of

Summer Branch Drop and its management on

an international level. Those investigations

revealed that Summer Branch Drop may not

be as rare as first thought and there may be

justification for rethinking the mantra often

quoted that the risk is so low, it does not

warrant any precautionary measures. These

are important matters that I am continuing to

work on, with a more detailed analysis

anticipated for publication later this year.

Stagecoach South Western Trains Ltd -v-

Hind & Steel

In December 2009, a substantially decayed

stem of a large ash tree fell from a private

property in Stains and damaged a train

causing over £300,000 worth of damage and

consequential costs. The written judgment

for this High Court case can be downloaded

at www.bailii.org/ew/cases/EWHC/

TCC/2014/1891.html, and the judge found

in favour of both defendants. There is a very

useful review of the legal authorities and

principles relating to a landowner’s duty in

paragraph 68 of the judgment.

Legal commentators report how the Judge

held that Ms Hind’s (the first defendant) duty

in respect of a tree on her land had extended

no further than the carrying out of periodic

inspection through informal observation. In

the absence of any trigger or warning sign of

problems with the tree, there was no

requirement to instruct a more detailed

inspection by an arboriculturist. She was not

required to clear ivy to inspect the base

herself or instruct an arboriculturist to do so.

The tree had been worked on before the

accident by the second defendant tree

surgeon, Mr Steel, but he had not been asked

to consider the health or safety of the tree.

The claim against him also failed because he

did not owe a duty of care to warn of any

structural instability, which could only have

been discovered through a close inspection.

Through my involvement as the expert

witness for Ms Hind, I pull out two issues that

may be of interest to UK tree managers:

Ivy: In my experience, ivy and its potential to

hinder the discovery of defects regularly

crops up in cases, with questions about

whether it should be removed as part of a

risk management regime. To date, there is

no definitive answer, but recent cases

provide some clues as to how the courts may

view this. In Micklewright -v- SCC, the

experts agreed that “It would not be standard

practice to remove heavy ivy from a tree

during a quick visual check.”, which has a

compelling logic in the context of the vast

numbers of trees that large landowners have

to manage. However, because it was agreed

between the experts, it was never tested in

the proceedings, and so that reference is

unlikely to carry any significant weight. In

this Stagecoach judgment, the matter of ivy

was considered in more detail, with the Judge

stating in paragraph 86: “I reject the

suggestion that as a reasonable and prudent

landowner, Ms Hind was obliged to carry out

inspections of the trunks of each of her

apparently-healthy trees, no matter how

difficult they were to access, and no matter

how much they might be covered in ivy. A

reasonable and prudent landowner in Ms

Hind's position was not obliged to struggle

her way through the nettles and brambles to

the foot of what appeared to be a healthy

tree, in order to pull off some of the ivy

leaves and then strip off the lattice work of

ivy stems from the base of the Tree in order

to look for decayed areas behind the ivy.”

Whether such an analysis could extend to a

formal inspection by an arboriculturist

remains to be clarified, but this judgment

does shed light on the likely expectations

from a homeowner implementing an informal

checking regime.

National Tree Safety Group (“NTSG”)

informal observations: At paragraph 53,

under Published Guidance, this judgment

refers to the NTSG guidance that informal

observations may be used as a means of

checking trees. For this case, it was

unchallenged that this was a legitimate form

of inspection; it was held that Ms Hind was

able to carry out such an inspection and did

so properly. This is the first judgment since

the NTSG document was published that has

directly referenced the informal observations

approach to inspections and, no doubt, many

homeowners will feel that it is a welcome

clarification on the nature of their

obligations. However, it does not

automatically follow that larger landowners,

who may have greater resources, can rely on

informal observations as being sufficient for

all types of circumstances. This is an aspect

that still requires clarification.

Finally, I am aware of suggestions that there

may be some significant similarities between

this case and Poll -v- Bartholomew because

both centred on multi-stemmed ash trees

with included bark unions. Having been

involved in both, my opinion is that no

meaningful comparisons can be drawn

between these two cases on those grounds.

Take-home points

There is nothing radically new here and not

much of this should come as any surprise to

the wise tree inspector. However, in the

same way that refresher training is helpful in

keeping up-to-date with specific skills, being

alerted to emerging concerns that arise from

legally oriented analysis can also be valuable.

Some obvious reminders include:

· Refresher training is an important element

of keeping current

· Drive-by tree inspections of roadside trees

should be done at slow speeds

· Spotters undertaking drive-by tree

inspections of roadside trees should only

be looking at trees, and not trying to

detect highway defects in the same

operation

· Large occluded wounds on old trees

should be carefully considered

· Severe imbalance of large branches or

whole trees should be carefully

considered, especially in combination with

other predisposing factors to failure

· Summer branch drop is a known risk to

specific groups of trees and that risk may

be elevated at the end of extended dry

summer periods followed by rain

· There is unlikely to be an automatic

presumption to remove ivy when

inspecting trees, but further investigations

may be required if there are obvious

indications of a potential problem

· Informal inspections are likely to be

acceptable for homeowners, but it is

unclear whether the same applies to larger

landholders

Although such reminders can be useful, they

cannot be a substitute for careful analysis

that brings to bear the experience of the

assessor on the specific circumstances of

each situation. Knowledge, experience and

common sense remain the cornerstones of

effective tree risk management, and anyone

still searching for simplistic formulaic

solutions should brace themselves for

disappointment.

Read more about assessing the potential for

tree failures in the articles at http://

www.barrelltreecare.co.uk/resources.php.

Keep up to date with tree risk management

developments on Jeremy’s Facebook page at

https://www.facebook.com/pages/Heritage-

Tree-Management/573985506028429.

A local authority and a tree surgeon have

been sentenced for safety failings after a

worker was injured when a tree he had been

felling landed on a railway line and was hit by

a train.

Peter Wood was carrying out tree work for

Mark Anthony Connelly near Ryton, Tyne &

Wear, next to the Newcastle to Carlisle rail-

way line, on 11 January 2012.

Newcastle Crown Court heard yesterday (4

July) that Connelly, trading as Practical Con-

servation Management, was contracted by

Gateshead Metropolitan Borough Council to

remove two poplar trees that were in danger

of falling onto the track.

During felling, one of the trees twisted and

fell onto the railway line, uprooting another

tree on its way. Connelly and Wood tried to

cut the tree away from the track, but while

doing so failed to hear an oncoming train,

which hit the tree.

As a result, Wood sustained a fractured right

ankle, a cut to the head and bruising.

The court was told the cost to Northern Rail

for repair of the train was more than

£97,000, while a further £7,000 was incurred

by Network Rail on callout, materials, ma-

chinery hire and delays to services. Network

Rail had not been told about the felling oper-

ation near its line.

An investigation by the Health and Safety Ex-

ecutive (HSE) found that Gateshead Council

failed to take reasonable steps to ensure that

Connelly was competent to carry out work on

large trees, such as checking if he had the

relevant qualifications. Had it done so, it

would have found out he was not, in fact, so

qualified.

HSE also found Connelly failed to put safety

measures in place that would have prevented

the tree falling towards the line.

Gateshead Metropolitan Borough Council was

fined £40,000 and ordered to pay £5,854 in

costs after pleading guilty to breaching Sec-

tion 3(1) of the Health and Safety at Work etc

Act 1974.

Mark Anthony Connelly was sentenced to 150

hours of unpaid work and ordered to pay

£5,854 in costs after pleading guilty to

breaching the same Act.

After the case, HSE inspector Jonathan Wills

said: "Mr Wood's painful injury and Northern

Rail's unexpected bill for almost £100,000

could all have been avoided.

"The decision to fell a mature poplar tree on

a steep slope within falling distance of an ac-

tive railway line without informing Network

Rail and not using a precautionary winch was

indicative of Mr Connelly's poor planning."

NHS Forest conference “Creating

Healing Environments”- 7th October

2014, Guild Park at Lancashire Care

NHS Trust.

This year, the NHS Forest conference focuses

on “Creating Healing Environments”, and will

celebrate and share some of the wonderful

activities, ideas and site developments in the

NHS Forest over the past few years. The plan

for the day includes; a) Presentations b)

Interactive workshops and c) a site visit to

Lancashire Care’s Guild Park near to Preston,

whose Grow Your Own project won the

overall NHS Sustainability Day Award this

year.

The NHS Forest will be making awards at the

event, to celebrate the achievements at the

project sites. We are pleased to announce

that, thanks to a generous donation, we are

able to offer four categories of awards each

with a £200 cash prize including:

• Largest Number of Trees Planted

• Most Innovative Site

• Best Community Engagement

• Most Pioneering Use of Green space by

Healthcare Professionals

An overall winner will receive an additional

£200.

You can book your place through Eventbrite;

the cost is £30.

Some free places are available for those who

might otherwise be unable to attend. Please

contact Mary Zacaroli for further details.

Sarah Dandy NHS Forest Co-ordinator

e: sarah.dandy@sustainablehealthcare.org.uk

Barcham Trees is to hold a conference which is claims will be the biggest

arboriculture event of its kind held in the UK.

The Big Barn Conference to be held at its headquarters in Ely, Cambridge-

shire, on 17 June 2015. Event organiser Barcham sales director Keith Sa-

cre said he expects 550 delegates to attend the free event to hear the

views of international arboriculture experts.

Forestry Commission England’s principal advisor on arboriculture. Jim

Smith will speak about the London i-Tree Project, Frederic Segur and Ian

Sear will talk about tree management in Lyon, France and Melbourne, Aus-

tralia, respectively and Dave Nowak of the USDA will speak about urban

forest management, the importance of inventory and the role of i-Tree.

Mike Raupp from the University of Maryland, USA, will speak about pests

and diseases, Henrik Sjoman from the University of Alnarp, Sweden and

Nina Bassuk Cornell University, USA will talk about tree species selection,

while Cecil Konijndijk van den Bosch University of Alnarp, Sweden will

share his knowledge on Urban Forest Governance.

Dr Mark Johnston, a speaker on the history of urban forestry, who chaired

the Trees, People and the Built Environment conference at Birmingham

University last month, will also chair this event.

"We believe our 2015 Big Barn Conference will be the biggest arboricultur-

al gathering of its kind ever held in the UK, and I am delighted we have

nine speakers from three continents to make the day a truly international

event," said Sacre. Places are offered on a first-come, first-served basis from 1 October and will in-clude lunch and refreshments.

Introduction

With international trade in untreated wood

and wood products, coupled with increased

global travel, the likelihood of the

introduction of exotic pests, disease

pathogens and decay fungi and their

becoming established and deleteriously

affecting the health status of the UK’s native

and plantation forests, and amenity trees is

now a realistic possibility. For example acute

oak decline, sudden oak death, oak

processionary moth, Pseudomonas bleeding

canker, horse chestnut leaf miner are now

considered serious threats to the health and

future longevity of many UK trees. The fact

that these pests and diseases have only

emerged in the past 8-10 years demonstrates

how new environments with few bio-control

predators and new host plants can result in

rapid infection and establishment. The

potential impact, if further more damaging

exotic pests and diseases were to be

introduced, would not only be the loss of

newly planted trees, but the loss of decades

of effort and investment in tree plantations,

as well as irreparable damage to UK native

biota and wood resources.

This article highlights a number of potential

pest and disease threats causing concern to

professionals in tree and shrub production,

planting and management regarding the

likelihood of their introduction into the UK

Potential Pest and Disease Threats to UK and Irish Trees

With increased global trade and international travel the threat of exotic pests and

diseases has never been higher. In this, the first part of a two part article, Dr Glynn

Percival from the Bartlett Tree Research and Diagnostic Laboratory based at the

University of Reading discusses potential pest and disease threats to UK and Irish

trees that are of concern to managers of trees and shrubs within our

urban forests as well as outline potential management strategies

that may be employed if, or when, outbreaks occur.

In the Winter edition Dr. Percival will look at Hemlock Woody Adelgid,

Bacterial Leaf Scorch and Thousand Canker Disease of Black Walnut.

and Ireland as well as discussing strategies

that could play an important role in their

management.

Emerald Ash Borer (EAB)

EAB (Agrilus planipennis) was first discovered

in South-eastern Michigan in 2002 and has

since spread throughout the Midwest and

portions of the eastern United States. EAB is

native to Asia including China, Japan, Russia

and Korea. EAB was probably introduced on

pallets or wood that was used to stabilize

heavy cargo. EAB attacks all ash species

native to the Midwest and is known to infest

certain elms and walnuts within its native

range in Asia. EAB larvae feed in the outer

sapwood of ash trees and can rapidly girdle

(ring bark) stems and branches. Trees often

die within one-to-three years following the

initial attack.

Identification: Adult beetles are emerald

green and approximately 1.25 cm long.

Larvae are segmented flat worms that can

reach 2.5 cm in length. EAB has a similar

appearance and life cycle to other Agrilus

borers such as the bronze birch borer and

the two lined chestnut borer.

Biology: Adults generally emerge from

infested wood in June and early July and feed

on leaves of ash where they create notches in

the leaf margins. Adults mate and females

lay up to 90 eggs in the bark crevices in

stems and branches. Eggs hatch within 10

days and the first instar larvae bores through

(Continued on page 30)

Potential Pest and Disease Threats to UK and Irish Trees

the bark into the sapwood. Larvae create “S”

shaped feeding galleries that wind through

the cambial area of the branches and stems.

Larvae complete development in the autumn

and overwinter as pre-pupae in chambers in

the sapwood. Pupation occurs in early spring

and adults emerge in late spring through

early summer leaving “D” shaped emergence

holes that are visible in bark of infested

stems and branches. One

generation occurs each

year and adults are

capable of flying at least a

half mile from the point of

emergence. Long distance

movement of EAB has been

attributed to transport of

infested wood and nursery

stock.

M a n a g e m e n t : E A B

treatments are most

effective when applied on

a preventative basis i.e.

before a tree has been

damaged. The most cost effective treatment

is a soil applied systemic insecticide

containing imidacloprid which acts as a

neurotoxin. This treatment is injected into

the root zone of a tree where it is absorbed

and translocated to the stem and branches.

(Continued from page 29)

EAB ALB

Susceptible Species Ash, Elm and Walnut Maple, Horse chestnut, Birch, Willow, Ash,

Poplar and Elm

Symptoms Notches on leaf margins, Woodpecker

activity

Leaf notching, Exit holes

Emergence time June and July (USA) June to October (USA)

Emergence hole D shaped >1cm diameter, may ooze sap, frass visible

Dispersal from hole > 1/2 mile Tend to remain on tree

Gallery shape S shaped feeding Galleries, packed

with frass

meandering galleries, packed with frass

Larvae that bore into the xylem are

controlled by this insecticide. Imidacloprid is

fully registered in the UK for the control of

chewing and sap sucking insects. However,

under UK pesticide guidelines imidacloprid

can only be applied in February-March and

October-November. If EAB does become

prevalent in the UK then imidacloprid will

prove a useful management option.

Within the US, stem injection of another

insecticide known as emamectin benzoate is

usually effective in controlling EAB infestation

of trees in the initial stages of attack. Stem

injection is then usually followed by soil

application of imidacloprid to prevent re-

infestation. At present however, emamectin

benzoate is not registered for use in the UK.

If EAB does become prevalent within UK

landscapes then consideration of off label

approval for this insecticide to be used may

be warranted.

Further management strategies include

heavily infested trees should be removed and

destroyed by chipping, burial, or burning.

Wood should not be stored nor be

transported from areas known to be infested

by EAB. Good arboricultural practice to

maintain the health of ash trees to include

pruning, fertilisation, mulching and irrigation

during dry periods will reduce stress and

improve the tolerance of trees to EAB attack.

Asian Longhorned Beetle (ALB)

Asian longhorned beetle (ALB) is a

destructive pest of maple although other

deciduous trees such as horse chestnut,

(Continued on page 32)

birch, willow, ash, poplar and elm can also be

attacked. ALB was introduced into the US

from China on untreated wood products. This

pest was first discovered in the United States

in Brooklyn in 1996 and later discovered in

New Jersey, Chicago, and, most recently, in

Maine. ALB was confirmed in the Paddock

Wood area of Maidstone in Kent by

government scientists in March 2012. ALB

larvae bore into stems and branches of host

trees creating galleries (tunnels) that

interrupt water and nutrient transport

resulting in dieback and decline of the tree.

Galleries can be so extensive that branches

can become structurally unsound and prone

to failure.

Identification: Adults are shiny black with

white spots, 2-4 cm long with antennae that

are longer than the body. Antennae have

alternating black and white stripes. Larvae

can grow to more than 5 cm in length and

feed within the wood of stems and branches.

Biology: Adults emerge from stems and

branches in spring through early autumn.

Emergence holes can be more than 1 cm in

diameter and may ooze sap. Sawdust (frass)

may be visible near the emergence wounds.

Adults are not strong fliers and tend to

remain on or near the host from which they

emerged where they feed on leaves.

Following mating, females chew 5 mm

depressions in the bark where they deposit

eggs. Each female can lay up to 120 eggs.

Eggs hatch soon after deposition and larvae

bore into the wood on stems and branches.

Larvae feed in the outer sapwood near the

bark surface when they are young, but tunnel

deeper into sound wood as they grow larger.

Galleries created by the larvae interrupt water

(Continued from page 31)

and nutrient transport and are responsible

for dieback, decline and death of the tree.

Larvae complete development the following

spring and pupate within the galleries and

emerge as adults. One generation occurs per

year.

Management: Within the US ALB is a

regulated pest that requires establishment of

quarantine by the US Department of

Agriculture when infested trees are detected.

Surveys are conducted to define the extent of

the infestation, and infested trees are then

removed and destroyed. Infested trees are

considered those that have emergence holes

and/or egg laying wounds. Buffer zones are

usually created whereby non-infested host

trees in the vicinity of infested ones are

removed or chemically treated in an attempt

to eradicate the pest and reduce the risk of

spread. In addition “regulated articles” cannot

be removed from the quarantine areas.

Regulated articles include firewood from

deciduous tree species, living and dead plant

material from all preferred or occasional

hosts, live plants to include nursery stock,

logs, branches, roots and plant debris larger

than 1.25cm in diameter. Similar to the US,

within the UK potential host trees within an

extended infested zone area are being

mapped and the size, species and numbers

of trees felled and incinerated is recorded.

Similar to the control outlined for EAB

systemic insecticides containing imidacloprid

should be applied to prevent larvae from

infesting trees. In addition to imidacloprid,

pyrethroid insecticides applied to the stem,

branches and leaves of host trees will

supplement the protection provided by

systemic insecticide treatments. These spray

treatments control adult beetles that feed on

leaves, larvae that hatch from eggs on bark

surfaces and deter females from creating egg

laying wounds. For optimal protection, two

spray treatments would be recommended per

year to take place in May/June and July/

August. Within the UK the pyrethroid

deltamethrin is a broad spectrum synthetic

insecticide fully registered for amenity trees

that is effective against insects following

ingestion and/or direct contact. Deltamethrin

persistence on foliage can last for 6-10

weeks. Pyrethroids such as deltamethrin

interfere with normal production and

conduction of nerve signals in the insect

nervous system. Deltamethrin in combination

with imidacloprid would prove a very useful

insecticide to aid in the control of ALB.

Asian Longhorned Beetle and Emerald Ash

Borer Distinguishing features.

Although these two beetles vary greatly in

appearance, it is often usual to see the

individual beetles on, for example, a single

visit to a site. It is important therefore to

identify the symptoms and damage caused

by borers in order to identify and control the

damage. The table below lists a number of

these borers distinguishing features.

Dr Glynn Percival

Bartlett UK

LTOA elect new chairman

The London Tree Officers Association

(LTOA) has elected Richard Edwards, tree

& woodland officer for the London

Borough of Croydon, as the new chair of

its executive committee.

Edwards said: "I am hoping to concentrate

on maximising the benefits that LTOA

membership can bring to grass-roots tree

officers to aid them in their day-to-day

activities, whether that be through

seminars, working groups or publications.

"I am a great believer in using the

exchange of information and knowledge

to support tree officers and develop their

skills, and we will be working hard over

the coming months to achieve this."

The new Vice Chair is John Parker,

arboriculture & landscape manager for

Transport for London (Central area). Full

details of the new committee are on the

LTOA website. Www.ltoa.org

Originally posted in the MTOA on-line

members forum on 31/07/2014 by Ruth Rose

of Stratford Borough council.

The Openness of Local Government Bodies

Regulations 2014 comes into force on 31st

July 2014. They were only laid in Parliament

on July 3rd, so no time at all before they

come into force. I only found out about them

yesterday (30th July 2014).

The Regulations deal with the filming and

recording of meetings and publication

requirements for decisions made by Local

Authority Officers. It would appear that any

decisions delegated to officers that:

grants a permission or license

affects the rights of an individual

awards a contract, or

incurs expenditure which materially

affects the local authorities financial position,

will need to be recorded.

The officer making the decision will need to

produce a written record as soon as practical

after taking the decision which must cover:

the date the decision was taken

what the decision was and the reasons for

the decision

details of alternative options considered

and why they were rejected

(in the case of express delegations) any

member who declared a conflict of interest

any background papers they have used

(non-published which has been materially

relied upon in writing a report)

The decision must be made available for

inspection by public:

at the offices of the relevant local

government body

on the website of the relevant local

government body

by other such means that the relevant

local government body considers appropriate

Whilst I’m not concerned about TPO

applications for consent, Section 211 Notices

and Hedgerow Removal Notices as these

would all be web-enabled and available to the

public, there are other areas of work which

require decisions and are not currently

publicised:

TPO Replacement Planting Notices (S206)

Replacement Hedgerow Notices

Work under the Miscellaneous Provisions

Act 1976

Requests for TPO’s to be served

Dealing with dead/dangerous trees

High Hedge Remedial works Notices

The list could go on.

I thought I would highlight this to other LA

officers as the deadline is imminent. I’ve not

given consideration to how I’m going to

record this information yet, but there are a

series of meetings at my authority next week

to see how to progress this.

If any of you are aware of these Regulations.

and have already put in place measures then

I’m sure we all would appreciate some help

on this. If you are not aware of them, then

you are now!

Please see the forum for updates here: -

Of reply directly to Ruth by clicking on her

name below.

R Rose

Stratford Borough council

Openness of Local Government Bodies Regulations 2014 in Force 31st July 2014

Introduction

Quantifying canopy cover has been identified

by many authors to be one of the first steps

in the management of the urban forest. For

example, in James Schwab’s book ‘Planning

the Urban Forest’, it states:

”The first step in reincorporating green

infrastructure into a community’s planning

framework is to measure urban forest canopy

and set canopy goals”.

Canopy cover, which is often also referred to

as tree canopy cover and urban canopy cover,

can be defined as the area of leaves,

branches, and stems of trees covering the

ground when viewed from above. Canopy

Cover is a two dimensional metric, indicating

the spread of canopy cover across an area. It

is not to be confused with Leaf Area Index

(LAI), which is a measure of the number of

layers of leaves per unit area of ground

(although Canopy Cover studies can be used

to estimate LAI).

Assessing canopy cover is popular because it

is relatively simple to determine from a

variety of means and it can be calculated at

relatively little expense.

Measuring canopy cover has helped city

planners, urban foresters, mayors and

communities see trees and forests in a new

way, focusing attention on green

infrastructure as a key component of

community planning, sustainability and

resilience. It is an easy-to-understand concept

that is useful in communicating messages

about our urban forests with both the public

and policy makers.

How can Canopy Cover be measured?

There are 3 main methods to obtain canopy

cover data;

1. Field Work Surveys

This method requires surveyors to visit a

number of sample plots and take direct

measurements on the trees within them. The

average Canopy Cover, along with its

variability, can then be estimated for the

entire area. The advantage of this method is

that you can also collect additional data on

tree species and tree size not normally

available using the other methods. It is

probably the most labour intensive, although

it could be incorporated into an existing

survey regime such as tree health and and

tree safety inspections.

In the last article we looked at what constitutes the ‘Urban Forest’, concluding that one of the

simplest ways to start assessing this resource is to look at Canopy Cover.

In this article we will briefly explore what canopy cover means, the methods by which it can be

assessed, and its uses.

Further reading is signposted within the article but also feel free to contact the author with any

queries at: Kenton@treeconomics.co.uk

Kenton Rogers

2. Random Point Method (using Aerial

Photography or other remotely sensed data)

This method involves desk study of aerial

imagery using a Geographical Information

System (GIS). The method can be used to

quantify tree cover by counting the relative

number of random points in each area which

are covered by trees. This is the principal

used by i-Tree Canopy. Its quick, cheap and

requires minimal training but only provides

information on overall canopy at the chosen

scale. It is however a very good starting point

to start looking at canopy cover.

3. Area Method

This method involves using aerial imagery

and digital mapping to determine the tree

canopies using

GIS, to calculate

tree cover for

given areas. This

method can

provide much finer

detail at any

chosen scale but

depending on

resolution the

aerial imagery can

be very expensive

to obtain. Another

disadvantage is

that it is still very

difficult to to get

any information

about other aspects of the trees such as the

species, height and even numbers of trees

when several individuals form a closed

canopy. In some cases, trees can also be

‘hidden’ within the shadows of large

buildings and a small proportion of shrubs

may also be mistaken for trees.

How do the methods compare?

There are few examples in the literature on

directly comparing the methods described,

although a study carried out by the City of

Toronto (2008) used the 3 different methods

which are reproduced in Table 1 below. The

study concluded that [for its purposes] point

sampling from aerial imagery was the most

cost effective, whilst also recognising that [in

this instance] it provided a conservative

estimate compared to the other methods.

(Continued on page 38)

Table 1: Comparison of different methods for assessing canopy cover in To-

ronto. Source: Every Tree Counts - a portrait of Toronto’s urban forest

(2008).

Method Result

(% tree canopy)

USDA Forest Service - automated classification of leaf on 2007 satellite

imagery

28%

City of Toronto - 2008 i-Tree Eco study, ocular estimate of canopy cover

(407 plots)

24%

USDA Forest Service - 9,998 point sample, manual interpretation of 2005

leaf-off aerial photos

19.9%

USDA Forest Service - 9,998 point sample, manual interpretation of 1999

leaf-off aerial photos

20.6%

City of Toronto Urban Forestry - small sample size, digitized manually from

2002 aerial photos with area estimates by land use

17.5%

University of Toronto - 2000 UFORE study, ocular estimates of canopy

cover in 211 sample plots

20.5%

The Toronto experience shows quite a high

variability in the different methods over a

period of 8 years, although this does not

necessarily mean that any one method is

incorrect, just that it needs to be interpreted

with consideration for the expected statistical

accuracy.

What can Tree Canopy Cover tell us?

At a very basic level Canopy Cover provides a

percentage figure of the amount of tree cover

in a given area and could also indicate how

much room there may be to plant more trees.

However, do not be fooled! even this basic

measurement can be implemented in a

variety of different ways, with varying levels

of sophistication and complexity.

Depending on how a project is set up Canopy

Cover can be assessed at the individual

property level, by ward or by borough,

through to the city, county or even country

scale.

Take for example the recent canopy cover

league table completed by University of

Technology, Sydney and 2020 Vision in

Australia1

. They are using the results of a

country wide canopy survey (see fig 1) to

benchmark and provide a baseline for their

aspirations to increase their urban

greenspace by 20% by 2020.

This example illustrates which cities have

good canopy cover, those which are

dominated by ‘hard’ surfaces and grey

infrastructure and those where opportunities

exist to increase canopy cover.

In many international canopy cover studies

the mapping of existing tree cover levels and

distribution has been used to set future

targets. This is regarded as good practice by

the US Conference of Mayors, the US

Department of Agriculture Forest Service, and

(Continued from page 37)

Fig 1: Australia’s Urban tree canopy cover at a glance. Source: Where are all the trees?

many non-for-profit organisations

including the Arbor Day Foundation

(US-based), American Forest (US-

based), the National Urban Forest

Association (Australia-based) and

the Trees and Design Action Group

(UK-based).

In the US, American Forests offers

some general guidelines for canopy

goals based on climate conditions

and land-use categories.

Although city wide figures are

helpful, especially in country wide

projects, tree cover is not uniform

throughout a city. Generally canopy

cover will change in relation to

land-use, geography and other

social and political factors.

Illustrating this point are two

separate studies carried out in the

US2

and the UK3

. These have

highlighted a trend where most of

the canopy cover in urban areas is

provided by residential areas, and

also, that it is often the most

deprived areas which have the

least tree cover.

A land use approach was adopted

by Natural Resources Wales, who

have recently completed a canopy

cover survey to look at the tree

cover in all of its urban areas4

.

They have compared their tree

cover for different land uses

within a city as well as comparing

overall canopy figures with other

cities throughout the world. The

results can be readily used to

(Continued on page 40)

Fig 2: Canopy Cover by Ward for Swansea Wales. Source:

Tree Cover in Wales’ Towns and Cities 2014 © Natural Re-

sources Wales

fig 3 An example of infill from Perth, Australia with an ob-

vious reduction in canopy cover. However, with canopy cov-

er assessed at the parcel level, city planners can now seek

to ensure that canopy cover levels

are maintained or enhanced as a

planning condition.

make comparisons between different cities,

or between different parts of the same city

(See fig 2). A study at this scale can help to

target tree planting where tree cover is lower,

delivering benefits to the areas that most

need it.

The University of Vermont Spatial Analytics

Laboratory have analysed the canopy cover at

the parcel level for a growing number of

cities in Virginia. At this scale it is possible to

use the canopy mapping as a tool for

maintaining or enhancing tree cover during

development by requiring levels of canopy

cover to be maintained or enhanced as a

planning condition See Fig 3 overleaf.

This is a particularly important issue for

many cities as the pace of development

accelerates to keep up with the demand of

evermore people moving into urban areas.

Increasing demand for space often means

that tree canopy is removed to make way for

building and development, often on

‘infill’ (see fig 4). Yet it is the canopy cover

which makes our towns and cities better

places to live, providing important ecosystem

services like urban heat island reduction and

air pollution filtration. Therefore measuring

canopy cover is crucial for establishing a

baseline from which to monitor future

progress.

Repeated measurements of Canopy Cover,

for instance using historical aerial

photographs or repeated surveys, can

highlight changes in tree cover over time and

space and there have been studies done in

Wales, England (already cited) and the US5

.

Although some cities and towns showed an

increase in canopy cover, the general trend

has been a gradual reduction in the area of

canopy, most probably due to the reasons

described above.

Another way in which canopy cover can be

used is to look at correlations between tree

cover and environmental performance of an

urban area. Canopy cover measurements can

be used with other data such as crime rates,

climate data or health and well being

statistics to provide insight into how urban

trees affect- and are affected by - various

social and climatic factors.

Work in Manchester, UK6

has assessed

canopy cover at the ward level and has

compared this with statistics on Acute

Respiratory Disease and Mental Health. It

found a positive correlation between tree

cover and reduced rates of hospital

admissions for these conditions. These

relations are important and the Clean Air Act

in the US recognises tree canopy

management plans as part of State air quality

management plans, based on the link

between trees, ambient temperature and

ozone levels.

Conclusions

Hopefully you’ve been given an insight into

how assessing canopy cover can be used in a

variety of ways for urban forest management.

We really have only just scratched the surface

of this fascinating subject. Thanks to

(Continued from page 39)

Fig 4: Tree cover and Urban Tree Canopy

(UTC) potential at the parcel level. Image cour-

tesy of J O Neil-Dunne, University of Vermont.

advances in Geographical Information

Systems, the measurement of tree benefits

and the sciences of Arboriculture and

Forestry there has never been a better time

to start using these tools to make our towns

and cities better places to live by supporting

decisions to get the right the right tree in the

right place.

References

1

Where are all the trees? Available at:

http://202020vision.com.au/research

2

Connecting People with Ecosystems in the

21st Century: An Assessment of our Nations

Urban Forests. USDA Forest Service

3

Trees in Towns II. Dept for Communities

and Local Government, London

4

Tree Cover in Wales’ Towns and Cities

Available at: http://

naturalresourceswales.gov.uk/our-work/

community-link-working-together-working-

with-you/tree-cover-in-wales-towns-and-

cities/?lang=en#.U9Yn9l5IlQ9

5

Nowak and Greenfield (2012). Available at:

http://www.itreetools.org/Canopy/

resources/

Tree_and_Impervious_Cover_change_in_US_Ci

ties_Nowak_Greenfield.pdf

6

Manchester Tree Audit 2. Available at:

http://www.redroseforest.co.uk/web/

images/stories/downloads/Valuing%

20Manchester's%20Trees%20-%20Tree%

Google can serve as "entry-level GIS for urban tree managers" Google's Fusion Tables web application can serve as a low-cost multi-user geographic information system (GIS) for urban forest managers,

Canadian researchers have concluded.

"Google Fusion Tables provide cloud-

based computing services for data man-

agement and easy user collaboration

through the Google Maps interface," the

team from Toronto's Ryerson University

said.

"Fusion Tables are oriented toward small-

er organizations that previously were

unable to publish data online due to limi-

tations of database knowledge and high

cost of start-up."

An interactive web-based mapping plat-

form, the CityTrees.ca project, tested the

technology's ability to map trees on the

university's campus, while query interface

enabled users to narrow down the tree

population by species, diameter, height,

and location.

"We found that Fusion Tables performed well as a storage medium for our campus tree data, which could easily be explored through our crea-

tion of a JavaScript- enabled query tool," they concluded - describing their efforts as "a roadmap for small to medium-sized urban forestry

organizations seeking to create interactive mapping applications".

Image: CityTrees.c

http://www.barcham.co.uk/

Over £25million of damage has been caused to new homes by trees over the last six years,

according to figures released by NHBC.

The UK’s leading warranty provider and standard setting body for new build homes is so con-

cerned by the scale of the claims that it has today issued guidance to home owners advising

them of the best practice when planting trees close to their homes.

The figures show that over £25million of claims were made by owners of new homes for dam-

age to their property caused by trees between 2008 and 2013. Last year alone, NHBC paid out

nearly £4million in claims following structural damage caused by trees.

As summer approaches, an NHBC guide offers practical advice to anyone thinking about plant-

ing new trees and shrubs or cutting back existing ones. Tips for homeowners include how to

calculate a suitable planting distance away from houses and where to go to check if the tree is

protected.

Richard Tamayo, NHBC’s Commercial Director, says: “New greenery can create a more attractive

garden as well as provide privacy and can help in reducing noise from a busy road. But roots

and branches can also cause expensive damage to homes as our figures show.

‘When an established tree is removed or a new one is added, it can affect the moisture content

of the surrounding soil. In clay soils, this can cause swelling of the ground or shrinkage. This

movement can potentially result in damage to the house foundations due to subsidence or

heave, particularly where the foundations have not been designed with trees in mind.

‘If the tree was added or removed before the house was sold by the builder, NHBC’s Buildmark

warranty may provide protection. However, if the tree was removed or planted by the homeown-

er subsequently NHBC cannot provide cover and the household insurance may also not cover the

damage.

‘This is an ideal time of year to start planting trees and shrubs ahead of those lazy summer days

in the garden. But anyone thinking about planting new trees or shrubs should spare a thought

for their home and their neighbours by getting an expert opinion before planting.’

X. fragiforme is a relatively common

fungus and is often found in clusters on

deadwood on forest floors. It is almost

exclusive to beech, although similar related

species can be found on birch, alder and

hazel. The fruiting bodies are small,

usually only around 5mm wide and are

dimpled over the surface, giving them a

‘warty’ appearance. If you’re lucky enough

to see fresh ones, they will be a light

salmon-pink shade, before they turn rusty

brown and then charcoal-black.

Superficially, H. fragiforme could be

confused with species of Nectria fungi,

although they are easy to tell apart. Crack

one of the fruiting bodies open and you

should see a layer of spore sacs just below

the surface, which surrounds a charcoal-

like layer in the centre. Crack open a

species of Nectria and it will pretty much

disintegrate. Whereas Nectria is mildly

parasitic and linked to canker formation in

many species, H. fragiforme is exclusively

saprotrophic and so can be used as a good

indicator of dead wood in limbs of beech. It

will also remain on wood for months, much

like miniature versions of King Alfred’s

cakes.

Hypoxylon is reported to exist latently

within the sapwood in healthy trees, and it

is only when limbs die back and moisture

levels are greatly reduced, that mycelium

will begin to colonise branches. White rot is

Xypoxylon fragiforme - Beech woodwart

There’s plenty of information out there on the most common 20 or so fungi we

see regularly on trees in the UK, so it makes sense to take a look at something

we might not be so familiar with. This edition’s fungus of note is Beech wood-

wart, Xypoxylon fragiforme. Proper identification is less important than for spe-

cies such as Ganoderma, but it is interesting and useful nevertheless.

the result, so branches

will snap like a piece

of cheap celery.

This is not a fungus

that can be managed in

any way and

regardless of whether

it is Xylaria, or Nectria,

the wood is almost

guaranteed to be dead.

Either way it’s an

interesting fungus and

one to look out for.

Enjoy!

Chris

Parker

Tweed

Back in the murky days of old when craggy,

tweed jacketed foresters ruled the Earth (or

at least their domains within the Forestry

Commission) I was a lowly pre-college

forestry student. Happily learning my craft in

Thetford Forest and soaking up all I could

about trees. One day my compatriots and I –

there were four in our jolly band- were

dispatched post haste to Lynford Arboretum

to deal with something extremely important.

Sadly, the intervening years and a

predilection for strong cider prevent me

disclosing what this something was…

However, the arboretum was a

revelation and I was to

return there many

times to be

among the

specimen

trees.

In one

quiet

corner

and set

against a

blackout of

Corsican Pine

plantation was a

Birch. It was autumn and

the trees were beginning to take

colour but this Birch stood out like a flame!

Clear yellow from top to bottom with nary a

leaf having fallen prey to the wind. It was

superb. Wandering over, I read the tag:

‘Betula lutea’ E.N. America’. And so began a

mostly unrequited love affair…

The Net

There have been brief meetings in other

arboreta, dalliances in nurseries and much

longing from afar in books and on the

internet. Sadly I never managed to possess

the object of my affection.

Despite having trawled around the nursery

trade I was unable to source a

specimen. Nurserymen

were unconvinced

about its

marketing

potential or

it’s

tolerance

of

nursery

conditions.

However the

specimens I’d

seen convinced me

that the search was worth

the candle so I carried on.

During the 2012 Ride for Research we visited

Birmingham Botanic Gardens and lo and

behold a Yellow Birch! This time labelled as

Betula alleghaniensis which is a synonym.

After a ‘bit of a tiff’ with Mick Boddy over

whether this tree was otherwise known as B.

lutea (cheers Mick!) I got to ask Simon

Gulliver (curator) where they had had their

specimen from. ‘From seed, I think from Kew’

was the reply. Sadly Kew couldn’t help either

so I was back to distant longing.

Fate

By chance an old friend contacted me out of

the blue and in conversation revealed that

they worked as a seed buyer for a major

plant company. Light bulb moment!

They eventually found some seed at which

juncture I bought half a kilo…

Now, Birch seeds are tiny so half a kilo

is a lot of seed. Sowing millions of

tiny Birch seed by hand is

beyond the pale even for a

tree spotter like me. No,

what I needed was a

friendly nursery to

grow these properly

and one was duly

located and

charged with the

job. This brings

us to the present

time where I

currently have a

small quantity of

Betula lutea being

grown on in cells.

Time will tell whether

these succeed and

grow into my arbor-

muse.

Character (istics)

For those of you still interested (bear with

me dear reader) I have listed the

characteristics of the tree below. My purpose

with this piece is really to raise the profile of

the tree and to increase its distribution in

amenity plantings. It deserves to be at least

as popular as the now seemingly ubiquitous

Betula nigra or Betula utilis. If you do plant

Yellow Birch –you really should you know-

and you spot an odd looking tall chap gazing

lovingly at it then don’t call the nice

gentlemen in the white coats. It’s likely to be

me and as anyone on the MTOA board will

attest: I’m quite harmless..

From my own perspective the tree has several

useful amenity attributes.

(Continued on page 50)

Bark colour and texture is great with a good

bit of variability between trees but generally

yellow-bronze.

Autumn colour as described in the article is

excellent. It is unclear whether this

performance is universal on all soil

types or whether it is enhanced

by acid soils.

Leaf shape is pleasing

with long, ribbed leaves

(think of a long

Hornbeam leaf) so

don’t instantly look

Birch-like.

The below is copied

from Wikipedia but

gives a nice summary

of the tree.

Betula alleghaniensis

(Yellow Birch), is a

species of birch native to

eastern North America,

from Newfoundland to Nova

Scotia, New Brunswick, southern

Quebec and Ontario, and the

southeast corner of Manitoba in Canada,

west to Minnesota, and south in the

Appalachian Mountains to northern Georgia.

It is a medium-sized deciduous tree reaching

20 m tall (exceptionally to 30 m) with a trunk

up to 80 cm diameter. The bark is smooth,

yellow-bronze, flaking in fine horizontal

strips, and often with small black marks and

scars. The twigs, when scraped, have a slight

scent of oil of wintergreen, though not as

strongly so as the related Sweet Birch. The

leaves are alternate, ovate, 6-12 cm long and

4-9 cm broad, with a finely serrated margin.

The flowers are wind-pollinated catkins 3-6

cm long, the male catkins pendulous, the

female catkins erect. The fruit, mature in fall,

is composed of numerous tiny winged seeds

packed between the catkin bracts.

Betula alleghaniensis is the provincial tree of

Quebec, where it is commonly called

merisier, a name which in France is used for

the wild cherry.

The name "yellow birch"

reflects the color of the

tree's bark.[1]

The wood of Betula

alleghaniensis is

extensively used for

flooring, cabinetry

and toothpicks.

Most wood sold as

birch in North

America is from this

tree. Several species

of Lepidoptera use

the species as a food

plant for their

caterpillars. See the list

of Lepidoptera that feed

on birches.

From October 2014 I should

have a number of these trees

available as cell grown. If you’re

interested in them either for nursery trials,

domestic plantings or amenity plantings then

please get in touch by emailing me at

lepus66@hotmail.com

I’ll only be covering costs of seed and

production so they’re likely to be £1.50-

£2.00 each.

Gareth Hare

Lichfield DC

(Continued from page 49)

Yellow Birch bark

Fanfare to the common man Richard Nicholson

The fog descended as I drove through the half-light south of Marlborough,

reflecting the beam from the headlights back at me. I nosed the car

cautiously along the road through Savernake Forest excited by what I was

going to see. The indistinct woods on either side gave way at road

junctions and the edges had a disturbing softness as oncoming cars

approached and we both tried to gauge the width of the road.

The Big Belly Oak came looming out of the

fog like an Ent in a hurry, catching me

unawares this evening. The Big Belly is an

Ancient Oak standing just beside the road on

the left hand side. Actually, let’s be honest,

Belly was probably

here long before the

road.

Ancient trees are

wonderful. Ancient

trees make you

gasp. Even though I

know where Big Belly

is I am always

surprised and

overawed by the

sheer size of him. He

just sits there as big

as a watch tower, the

ancient guardian of

the forest. I pulled

over and walked

back through the

fog. If I’m going to

get run over, this

would be a great

place for it to

happen. Big Belly is

squat, bulbous,

rooted to the ground, immovable. My visit is

so infinitesimal in his existence, but the

effect he has on me I carry to this day. The

scent of the forest, the absolute silence

broken only by the sound of drips where fog

condensed on his long fingers, and dropped,

disturbing the leaves on the ground.

Because not only is Big Belly an Ancient tree,

he is also a pollard.

Centuries ago, when

Big Belly wasn’t big

nor had much of a

belly, in fact when he

was quite a slim

almost willowy

young thing,

someone beheaded

him. The act turned

Big Belly from a

forest tree with a

useful life span on

perhaps 150 years to

a timber producing

monster that is still

growing, centuries

later. This act was

part of an industrial

revolution that had

been going on in in

the green and

verdant landscape

for thousands of

years. This was the

start of intensive timber production from Big

Belly and millions like him that not even the

conifer monocultures of today can compete

with. Because every so many years a

proportion of the regrowth, mainly small

diameter branch wood was removed and

every time Big Belly responded by producing

more shoots which self-selected and grew

into new branches ready for the process to

be repeated. We cannot quantify how many

hundreds of times Big Belly has been

harvested. All that timber from just one tree.

My fascination with pollards started when I

first developed an interest in trees. Growing

up within a stone’s throw of the Castle Park

in Colchester, we used the Lime trees that

grow in a line against the park wall as goal

posts. They didn’t look like the other trees in

the park; they had substantial trunks but

compact, dense bushy canopies. One day we

turned up to find a man up a ladder with a

handsaw cutting all the branches off. We sat

and watched (and shouted rude comments I

seem to remember) until the man had

removed and thrown to the ground the last

branch. The tree stood there like a weathered

monolith, not unlike some of the Roman

ruins that give the park its name.

Considering the hard time we had given him,

the man from the Council was friendly

enough and answered all our questions

about not killing the tree, why all the

branches were the same size, when would he

have to do it again and would he play

football with us now? Years later I became an

arboriculturist but in all my years of

climbing, I only got to pollard about half a

dozen trees.

The oldest record of the practice of

pollarding I know of is contained in a

manuscript dating from 1523 called The Arte

of Husbandrye by one Fitzherbert:

If a tree be heeded and used to be

topped and cropped at everye xii or xvi

years ende or thereabout it will beare

moche more woode by process of tyme

than if it were not cropped and muche

more profyte to the owner.

Let hymme beginne at the

nethermoste boughe first and with a

light axe for an (one) hande to cut the

boughe on bothe sydes a foote or two

foote from the bodye of the tree. A

specially cut it more on the nether

syde than the over (upper) syde so

that the boughe fall not straight down

but turn on the syde and it shall not

flawe (strip) nor breake no barke. And

every boughe shall have a new head

and beare mooche more woode. And

by thy wylle without though must

needs do it, heade him not when the

wynde standeth in the north or in the

easte, and beware that thou croppe

him not in sappe tyme.

Pollarding or ‘polling’ can be defined as

‘beheading or polling a maiden tree at 2-3m

above the ground’. The timber produced was

used for firewood, wood products like tool

handles, and small diameter building timber.

Most rural dwellings used small diameter

timber for rafters. The rafters in our cottage

which dates from 1680 are ash poles. I have

no idea how many times the thatch has been

renewed and the rafters replaced, but the last

time it was done, probably in the 1920s,

small diameter de-barked ash poles were

used. I like to think that they came from

some of the old Ash trees growing above the

village, near the heath.

Words like ‘lop’, ‘top’ and ‘brash’ describe

the arisings. Brash was used for animal

fodder, probably cut in the summer when in

leaf and either fed directly to animals or

stored for use as winter feed. Herdwick

Sheep still browse on Ash fodder in hill farms

in the Lake District. Holly was also used for

fodder; there are good examples of holly

pollards in Windsor Great Park remaining to

this day.

(Continued on page 54)

Of course, Fitzherbert was writing for

landowners, men of learning, those that were

educated. Both Evelyn in the 1664 Sylva or a

discourse of Forest trees and John Mortimer

in his The Whole Art of Husbandry: Or, the

Way of Managing and Improving of Land

written in 1716, talk about planting trees for

timber. Trees that would be high pruned by

the removal of the small lower branches,

producing clean stemmed trees desired by

the Navy, industry and builders of great

buildings. The common man had no use for

these and had neither the tools nor the

capability to deal with them. The common

man probably didn’t plant many trees either.

Those for whom common land provided their

livelihood would stop grazing their animals

in areas to allow the unending cycle of seed/

sapling/tree, the process we refer to as

‘natural regeneration’, to take place.

My view is that pollarding was the work of

the common man. And he, by trial and error,

managed to develop a harvesting cycle that

not only didn’t kill the tree but that produced

useable timber for his needs and fodder for

his livestock. The mistakes, and there must

have been plenty of those, have returned to

the forest floor. We are walking on all the

trees that were killed by too vigorous a

pollarding regime and that decayed and

returned to the soil. Common man

discovered that age matters. We know now

that a young tree, a maiden, has a balance of

dynamic to static mass that will mean that it

will have sufficient carbohydrate reserves to

regrow. An older tree has more static mass,

more wood laid down which is no longer

functioning, than dynamic mass, the active

functioning wood. Common man also

regarded age as self-limiting because the

older a tree is, the thicker is the trunk. In the

(Continued from page 53)

days of axes it was easier to behead a

younger tree with a small girth than an older

one with a larger girth.

The landscape of pollard trees was a wood

pasture, either a woodland where wood is

permanently available, or a pasture with

trees, which description depends on the

density of the trees. This land use developed

out of the pre-historic practice of de-

pasturing cattle into woodlands when normal

grazing became scarce. Obviously the long

term grazing and browsing of cattle

presented a serious problem by destroying

the new trees which would eventually result

in the wood declining. On the other hand,

too many trees reduced the amount of

herbage. The balance was struck with the

help of pollarding, where timber and fodder

can be produced beyond the reach of grazing

cattle. It’s like coppicing on legs. The fact

that the cattle would be browsing on the

natural regeneration of the woodland floor is

not an issue for the cattle owner who is

growing a fodder crop 2-3m above ground.

So what is the reason that centuries old

pollards like The Big Belly Oak have survived

to this day? Well it is partly accident and

partly by design. Some like those in Hatfield

Forest survived on land being retained as

Common land, continually managed by

pollarding and some survived by being

incorporated into forests or chases (as in

hunting land; think of the New Forest) and

deer parks. We know this because of

historical records. Roger Tavener, a Surveyor

for the Court of Augmentations (a body set

up to better control land and finances)

provided condition reports on woodland

throughout the country. In 1565 he recorded

a visit to Meere Park in Wiltshire:

the park has old oaks whereof 30 are

timber, the rest ruinous and shells the

number 600

These ruinous shells are almost certainly

formerly pollard trees now no longer

managed as such because the land is now in

private ownership. He also described the use

of pollards at a wood called Little Park in

Essex:

divers oaks, ashes and hornbeams

commonly used to be shred for browse

for the deer and there be also growing

divers other oaks being timber and

meet for pole and rail.

and at Oakley Park, Shropshire:

but the rest have been of old time

lopped and topped and the lopps and

tops thereof yearly to be taken will

scarecely suffice for browse for the

deer, and the said browsewood will

scarecely suffice for the necessary

firewood of the keeper there.

Even in 1565 some of the old trees had lost

vigour and were probably in a spiral of

decline. In all likelihood, these would not

have been cut down. What was the point?

There was no value in the timber and the

effort required using the basic saws and axes

of the day was not an option. In the old days,

as in most primitive societies today, people

didn’t waste energy producing a product with

no value simply to make the place look tidy.

Tidy landscapes are a modern day

phenomenon as land was developed for

recreation rather than artisan production.

There is a description of such an artisan

landscape, and this is my favourite woodland

quote ever, from the Reverend Francis Kilvert

who visited Moccas Park in Hereford in 1876.

Rev Kilvert was a diarist and recorder of rural

life. In April 1876 he wrote:

‘we came…slipping, tearing and

sliding through the oak and birch and

fallow wood of which there seemed to

be underfoot an accumulation of

(Continued on page 56)

several feet, the gathering ruin and

decay probably of centuries.

‘I fear those grey old men of Moccas,

those grey, gnarled, low-browed,

knock-kneed, bowed, bent, huge,

strange, long-armed, deformed,

hunchbacked, and misshaped oak men

that stand watching and waiting

century after century biding God’s

time with both feet in the grave and

yet tiring down and seeing out

generation after generation….No

human hand set those oaks. They are

‘trees that the lord hath planted’. They

look as if they had been at the

beginning and making of the world

and they will probably see its end’.

To bring the story up to the present day,

some of the remaining medieval woods,

enclosures and common land were bought

out in the early 19th

century and largely

planted to oak. Alice Holt Forest in

Hampshire is a prime example of this. Within

these woods planting

would have taken place

around the veteran

pollard hulks, rather

than them being

removed. Where the

Deer Removal Act of

1851 was

implemented, natural

regeneration proceeded unencumbered by

grazing pressure. And deep within the woods

the veteran pollards survived. But they

continued to grow, unmanaged, developing

massive crowns that they had never

produced before and that their supporting

structures were not optimised to cope with.

This hadn’t happened before; pollards had

always been managed on a cycle to produce

a product, unless they were old,

unproductive or too decrepit, in which case

they were ignored and they fell apart. The

canopy managed by the pollarding cycle had

been kept small and the aged trunks were

able to support it.

Two of our better known pollard landscapes

are Epping Forest and Burnham Beeches. The

Hornbeam pollards of Epping Forest were

described by William Morris, the Victorian

Designer as ‘very curious and characteristic

wood as can be seen nowhere else’. The

Essex Naturalist Series records that

pollarding in Epping Forest almost certainly

predates 1130 when the forest was

established as a Royal Forest by Henry 1st

.

Commoners rights to lop continued in Epping

Forest up until 1878 when they were

extinguished by the Epping Forest Act. At

this point the purpose of the forest changed

and with it Victorian attitudes to the

deformed, misshapen but useful and

productive pollards. Pollards were protected

by the Act but public opinion, through the

development of the forest as public open

space, was now tending towards

‘naturalness’ and ‘beauty’. In the absence of

grottos and waterfalls and

such like that are seen

in some of the

‘natural’ gardens of

the time, the best that

could be achieved at

Epping was the

replacement of

pollards with un-pruned,

natural trees. Pollarding was industrial timber

collection, yesterday’s product no longer

required. It is prescient of the anti-conifer

attitudes of the late 20th

century and the

desire to return forests to native broadleaf

woodland.

Burnham Beeches was bought by the

Corporation of London showing remarkable

foresight in 1888, to stop a housing

development and in order to keep the

(Continued from page 55)

“trees are now the

preserve of the learned

and wise”

woodland as a public open space for all to

enjoy. Burnham Beeches contains both

maiden trees and some fine old beech

pollards. It is just 25 miles from London and

is a mecca for anyone who likes their trees to

be gnarled, misshapen and full of stories of

man’s

relationship

with trees over

the years. Gray

wrote part of

his Elegy here

and the site

was also

visited by

Mendelssohn,

Shelley and

Byron.

Burnham

Beeches is the

focus of

modern

attempts to

understand

the lapsed

pollard. The

trees are now

the preserve of

the learned

and wise and

science has

replaced trial

and error.

Having ceased

to need their

timber they

have lapsed

into senility and we have no history, no

handed down knowledge of how to look after

them. Ian Rotherham of Sheffield Hallam

University refers to them as ‘retired veterans’

which is a delightful phrase neatly summing

up their status.

Perhaps we never did know how to look after

them. We simply used them and there were

sufficient to provide for us. If they died or

ceased to become productive, we moved to

another one; there was always a new maiden

to behead. Perhaps there never was a fall-

back position to restore them. Perhaps there

is no art to re-discover, rather, we just need

to develop

ways of

maintaining

them. And like

our

commoners of

old it is still

important to

create new

ones for the

future. As a

Tree Officer,

years ago I

went to see a

large Oak that

a resident had

growing in her

back garden.

In response to

my comment

about what a

fantastic tree

she had, she

replied, “Oh

it’s not mine

dear, I just

look after it

while I live

here”. We

should adopt

this notion: we

do not own these monoliths, we are merely

their stewards and we should look after them

for future generations. Fortunately, as they

grow old they have accrue other values, as

niche habitats value as well as a scarcity

value. This makes them important to a wider

range of nature conservation groups who

have engaged with them, can speak of them

(Continued on page 58)

in their vocabulary and write eloquently of

them. For me, they continue to have the

‘wow’ factor; their fantasy, almost mythical

form dares you to harm them.

Management challenges today include the

need to make sure they remain relatively

undangerous to the general public and to

avoid the situation where they just gradually

fall in to decay and disrepair. Of course, this

is exactly what they have been doing for

centuries but previously they could be left in

peace, enjoying the woods to the end of their

days, for centuries after they stopped

working. The difference now is that there are

fewer of them and they are more isolated

than before. This is their scarcity value and

this article is just one attempt to record and

measure their importance in ways other than

timber and produce value.

And now I live just a few yards from another

pollard, this time one with an important

social significance. However the Tolpuddle

Martyrs tree, a Sycamore is not a true pollard.

It was pollarded on safety grounds in the

1980’s when it was taken over by the

National Trust. Early photographs in the local

museum show a magnificent open grown tree

with a major secondary stem arising on the

western side. A later photo shows that the

top of the tree had snapped out and signs of

vigorous regrowth. This noble tree, one of

the 50 great trees of Britain that were

dedicated by the Tree Council to mark the

Queen’s Diamond Jubilee in 2002, was the

tree beneath which the first Trades Union

was founded. In 1833 a group of

farmworkers formed a Union to protest about

their wages and swore an oath that they

would protect each other’s families if they

fell on hard times. For this, in February 24th

1834, six of the men were arrested and jailed

by the authorities who had been unnerved by

the recent Swing Riots and who had an eye

on the Revolutionary events that were

occurring in France. From Dorchester prison

the six were transported to Van Dieman’s

land, modern day Tasmania. The National

Trust reckon that the tree, a magnificent ivy-

clad hollow carcass, is around 320 years old

which means that it would have been a

substantial 150 years old when the Martyrs

met beneath it.

It is a Sycamore, a common tree, often

described by foresters as a weed species and

one that common man rarely pollarded, Oak,

Beech, Ash and Hornbeam being the timber

of choice. But here it is, a proud sentinel in

the middle of the village. The regrowth

stretches upwards from the jail of ivy that

encircles the hollow trunk, one limb for each

of the Martyrs, George Loveless, Methodist

preacher, and his brother James, Thomas and

John Standfield, James Brine and James

Hammett; a fanfare to the common man.

I think that it is fitting that the tree most

commonly associated with the common man

should survive to this day as a pollard, as a

monument to this practice, even if it is just a

youngster compared to The Big Belly Oak,

one of the truly grand old men of the 50

great trees of Britain club.

East Dorset District Council.

Trees are Worth It – arborists know it, foresters know it and there

is an increasing wave of professions that are beginning to

expound the virtues of trees too from Health, architects, town

planners and politicians. But what about the man, woman, child

on the street do they really know what trees do for us? Trees are

Worth It, an initiative of the Midlands Trees and Design Action

Group (TDAG Midlands) forum intended to bring this knowledge

to a wider audience.

Citizen Science: Treezilla is a web site closely linked with citizen

science through The Open University, The Open Science

Laboratory and other organisations including Forest Research . It

is a project to map trees especially in urban areas of Britain and

it’s aim is to promote the ecosystem benefits of trees by giving

them a monetary value so highlighting the importance of trees in

our world and raising public awareness.

Using the Treezilla website TDAG Midlands temporarily tied 'price

tags' to prominent trees in towns and cities across the

region. Through the local tree officer network and other TDAG

contacts schools, tree wardens, individuals and businesses some 50

individual trees were tagged with the owners’ consent for one day

only. Through Treezilla we all input the stem diameter, height

and the species of our target tree and the software calculated the

eco benefits provided by that individual tree in respect of

greenhouse gas, water management, energy benefits and air

quality as a monetary value. This was written on the label in

waterproof ink!

A Soggy Success: The British climate is nothing if not

unpredictable. But on the 4th June the day chosen for the Trees

Are Worth It initiative it was horrendous! The drizzle across most

on the country turned in to localised downpours on and off during

the day and the whole thing could have been a complete flop had

it not been for the hardiness of tree officers, tree wardens and

dedicated people from Cirencester to Lichfield and the durability

of the labels funded by the events’ three sponsors, the

Arboricultural Association, Acorn Environmental Management

Group and The Municipal Tree Officers Association.

In Lichfield, the City Council’s Open

Spaces officer engaged with the

town’s crier for added attention

grabbing. In Coventry the newly

former Tree Warden Network and

canine companion (dog’s need trees

too!) tagged a lime tree in Cuckoo

Lane which Treezilla estimates is

worth £359.73 in stored CO2 alone.

Across Stratford on Avon, Kineton,

Rugeley, Cirencester businesses,

charities, tree and forestry officers

played their part. In Birmingham

around St Philip’s cathedral 8 trees

including a Camperdown Elm were

tagged with a total monetary value

for air pollutants absorbed of £124.16

equalling almost 14kgs of particulates

per annum. Whilst in Cirencester a

17m beech was recorded with a value

for storm water interception of £10.35

equating to some 6,211 litres per

annum.

Trees are Definitely Worth it!

All who took part were disappointed

only by the weather which limited the

success of the day but there was very

positive feedback from all

participants. Visit www.treezilla.org

for further information or

www.tdag.org.uk to broaden your

knowledge and appreciation for trees

and register your interest for next

year’s event.

Julie Sadler

Birmingham City Council

Has it a pulse?

Tree Health day with the MTOA

Welcome to another great MTOA Seminar.

When and where? 24th

September 2014 at the Birmingham Botanic Gardens, Westbourne Road,

Edgbaston, Birmingham, B15 3TR.

(click here for the map location

The MTOA continue to bring you must attend seminars and this day will look at measuring tree

health and tree health crisis preparedness, please see below for the speaker details.

The itinerary for the day is;

9.00 – 9.30 Registration, tea and coffee

9.30 – 9.45 Moray Simpson (Wrexham council)– Introduction to the day & MTOA News.

9.45 – 10.00 A welcome from Rod Jones, Faculty Director for BMet College and our host for

the day.

10.00 –11.15 Paul Davis (Hansatech Ltd.), “Chlorophyll Fluorescence for tree health assess-

ment”.

11.15 – 11.30 Comfort Break

11.20 – 12.30 Julie Bolton (West Sussex County Council), “The Impacts of Large Scale Tree

Loss”

Please note this session will include a roundtable on preparing a strategy for

sustainable tree cover.

12.30 – 13.30 Lunch

13.30 – 14.45 Outside field try-outs with the Arborcheck system

14.45 – 15.00 Comfort Break.

15.00 – 16.00 Jon Stokes (Tree Council), “Who is going to stop the decline”?

16.00 – 16.15 Summing Up & Final Questions.

All this for only £20, yes £20.00 for MTOA, CAS and ISA members. Non- members £65

(dependant on space availability), bookable in advance by contacting Jean McDermott on 0121

556 8302, enquiries@mtoa.co.uk

Advertising in the Axe, members go free!

We publish four issues a year in full colour:

Winter: 2014/5 12th

November (copy deadline 1st November)

Spring 2015 15th February (copy deadline 1st February)

Summer 2015 17th May (copy deadline 1st May)

Autumn: 2015 13th

August (copy deadline 1st August)

If you are looking to advertise then please see the rates below. If you are a member and

wish to place a job advert then this can usually be accommodated free of charge contact the

Editor straight away.

Back page: £250

Inside covers: £200

Full page: £175

Half page: £100

Quarter page: £50

If booking a run of four full page adverts in consecutive issues, then you will receive the

final advert in the 4th edition for free. Advertisers who pay for ads in advance (by the pub-

lication of the first edition the advert runs in) receive an additional 5% discount. Payments

received after that date will not qualify for the prepayment discount.

And finally.

My third Edition back in the Editors role and things seem to be going well both for the magazine

and the MTOA in general. We are represented and most “top tables” and attract attention from

ICF, AA, DEFRA, Tree Council and such on a regular basis.

As you can see from the advert on page 13 the Axe is getting distributed far and wide and in big

numbers but this is hardly a surprise when you look at the strength of the contributing authors

and the depth and variety of the articles, and this edition is probably the strongest so far in that

respect, lets hope we can keep it up.

However, and there’s usually a however, we don’t see many articles coming from within the

ranks of the Municipal Arborists though, and advertising revenue is also non-existent so there is

still some huge improvements to be made.

The big issue on the horizon for many of us though is the constant onslaught of

the LA financial cuts. Jobs seem to be disappearing at a rate that’s faster than the

loss of Ash trees. You need to be represented at our September meeting where

strategies to cope with the large scale loss of trees will be discussed in depth,

and the thorny issue of who is going to manage this transition to a new species

diversity matrix. It is a huge task, so prepare yourself. Mac

mailto:enquiries@mtoa.co.uk?subject=MTOA%20membership