This is a public talk given at the Jubilee Institute, Rothbury, Northumberland on 30 May 2013. The presentation provides an overview of the role and importance of ash in British woodlands, and then goes on to describe the ash dieback disease (Chalara fraxinea). The current status and spread of the disease is discussed, together with a summary of current strategies to understand and control the spread of the pathogen. Important populations of ash are identified, especially those in Cumbria, and the lecture highlights the potential impact of the dieback disease on the natural and cultural heritage of Britain.

1. Ash Dieback Disease Public Talk
Ash Trees and their Future in Britain
Ted Wilson
Silviculturist
Jubilee Institute
Rothbury, Northumberland
30 May 2013
First presented: 30 05 2013
This version: 1.1, 31 10 2013

2. Outline for Talk
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Introduction to Tree Health
Ash – biology and history
Ash in woodlands and the landscape
Ash dieback disease (Chalara fraxinea)
Action: Hope for the future?
Questions

3. Biosecurity: Chalara is the latest on a growing list of
pests/pathogens
25th July 2012
Which tree species to plant for a changing
environment
Source:
Forestry Commission 2012

4. Recent arrivals
Decade of Contagion?
2002
2003
2006
2010
2011
2012
2009
2002
2011
2005
2012
Source: Barnaby Wylder 2013

5. Ash distribution across Europe
Source: EUFORGEN

6. Ash in the UK
Source: Forestry Commission 2013

7. Ash in the UK
Source: Forestry Commission 2013

8. Ash in the UK
Source: Forestry Commission 2013

9. Foliage and Reproduction

15. Ash – a fine
timber tree

16. Uses for Ash

17. The World Ash Tree
Wagner – The Ring Cycle
Bryn Terfel as Wotan, holding the Ash Spear
Ring Cycle, Royal Opera, Covent Garden, 2012

18. Ash in Cumbria – the Gosforth Cross

19. Ash in Cumbria
• > 2,400 ha of woodland
• > 550,000 individual
trees outside woodland
• Dominant species on
several soil types/
locations
• Important associate in
many woodlands
• Source: Forestry Commission
Source: Flora of Cumbria, 1997

20. St. Andrew’s Church
Penrith
Ash is a common species
in parks and towns

21. Weeping ash
St. Andrew’s Church
Penrith

22. Physiography
of Cumbria
Borrowdale
Source: Ratcliffe, Lakeland, New Naturalist

23. Woodlands and trees in Borrowdale, Cumbria

24. Key components of the Atlantic oakwoods
in Borrowdale, Cumbria
Ancient and recent secondary woods containing a range of woodland types1
Complex of woodland types:
Oak-birch woodland (W17)
Birch woodland (W4, W11,W17)
Oak-hazel woodland (W9, W11)
Hazel woodland (W?9)
Hazel-ash woodland (W9)
Sallow scrub (W?1-6)
Ash-wych elm woodland (W9)
Holly and/or rowan scrub (W??)
Alder-ash woodland on mineral soil (W7)
Alder-willow woodland on organic soil (W1-6)
Beech-oak woodland (W14, W15)
1Coding
from National Vegetation Classification (Rodwell 1991)
Source: G.Peterken

25. Biodiversity: Butterflies
Selection of species associated with western oakwoods
Sunart
Photos from Millennium Atlas
Chequered skipper
Dartmoor woods
High brown fritillary
Pearl-bordered fritillary
Brown hairstreak
Green hairstreak
Silver-washed fritillary
Purple emperor

26. Biodiversity: Specialised western vascular plants
associated with Atlantic oakwoods
Cow wheat
Melampyrum pratense
Bladderseed
Physospermum
cornubiense
Irish spurge
Euphorbia hyberna
Bastard balm
Melittis melissophyllum
Pictures: G. Peterken

27. Biodiversity: Mosses and liverworts
Isothecium myosuroides
Radula voluta
The lower row shows examples of species
restricted to an oceanic climate (‘Atlantic
bryophytes’). Moisture and light levels are
key habitat determinants.
Plagiochila atlantica
Adelanthus descipiens
Photos from Porley and Hodgetts, New Naturalist 97
Source: G.Peterken

28. Biodiversity: Lichens
Centre for oceanic epiphytic lichens
Particularly associated with large trees and glades
Top three
native tree
genera
Number of
species
Oaks
303
Ash
230
Beech
194
Name of Wood, Location
Number of
species
Camasine Woods, Sunart
174
Great Wood, Borrowdale
101
Low Stile Wood, Borrowdale
103
Coed Crafnant
100
Dizzard, Cornwall
114
New Forest, individual woods
116-160
Lowland coppices
10-70
Lowland oak plantations
16-80
Early surveys by Francis Rose, 1974
Source: G.Peterken

29. Ash woodland
Great Mell Fell, Cumbria

30. Lichens and mosses on ash
Great Mell Fell, Cumbria

31. Pollarded ash trees, Watendlath

32. Pollarded trees in Borrowdale

33. Ancient Ash Pollards
on the Sognefjord, Norway
Source: Kate Holl, Scottish Natural Heritage

34. Fraxinus excelsior pollards
Seathwaite Wood

35. Ash pollard
Near Rosthwaite, Borrowdale, Cumbria
Photo: E.R. Wilson 2012

36. Ash pollard
Photo: E.R. Wilson 2012
Near Glaramara, Borrowdale, Cumbria

37. Ash pollard
St John’s in the
Vale, Cumbria
E.R. Wilson 2012

38. Ash Dieback Disease
(Chalara fraxinea)
• Fungal infection
– Spreads by airborne spores
• First identified in Europe in
1992 (Poland)
• High levels of mortality
reported in Denmark
• Small degree of genetic
resistance known (2-5%)
• February 2012
– consignment of seedlings from
Netherlands
• October 2012
– Fera confirmed first cases in
“wider environment”
Photo: Forestry Commission 2012

39. Forestry Commission
How to Identify Chalara fraxinea
on ash trees
YouTube Video

40. Ash Dieback Disease
(Chalara fraxinea)
• November 2012 –
– Cobra Committee Meets
– Forestry Commission
National Survey –
hundreds of staff across
agencies
– Trace Forward surveys
ongoing
• Disease Categories:
– Nursery sites
– Recently planted sites
– Wider environment, e.g.
established woodland
Photo: Forestry Commission 2012

41. Signs of disease
Source: Forestry Commission 2012

42. Trace Forward: Newly planted seedling showing
signs of ash dieback disease (Chalara fraxinea)
Photo: Sharon Rodhouse 2012

43. Wider Environment: A mature ash tree with
Signs of ash dieback disease (Chalara fraxinea)
Photo: Sharon Rodhouse 2012

44. Ash Dieback in Denmark
Source: Barnaby Wylder, Forestry Commission 2012.

45. Ash Dieback in Sweden
Photo: Mari Jonsson,
Swedish University of Agricultural Sciences

46. Ash Dieback Locations
6 November 2012
Wider Environment
Newly Planted/Nurseries
Source: Forestry Commission

47. Ash Dieback Locations
22 November 2012
Wider Environment
Newly Planted/Nurseries
Source: Forestry Commission

48. Ash Dieback Locations
18 February 2013
Wider Environment
Newly Planted/Nurseries
Source: Forestry Commission

49. Ash Dieback Locations
28 May 2013
Wider Environment
Newly Planted/Nurseries
Source: Forestry Commission

50. Confirmed reports of ash dieback disease (Chalara fraxinea) in Britain
1 November 2012 to 28 May 2013
Reports
600
Nov 2012
Dec 2012
Jan 2013
Mar 2013
Feb 2013
Apr 2013
May 2013
500
400
300
200
100
0
0
20
40
60
80
100
120
140
160
180
200
Days from Start of Outbreak
Nursery Sites
Wider Environment
Recently Planted Sites
Total
Data: Forestry Commission 2012-2013
Graphic: AshStat/Silviculture Research International © 2013

51. Recent planting
Source: Barnaby Wylder, Forestry Commission 2012.

52. Disease Status
28 May 2013
Confirmed Findings (UK)
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Nursery Sites – 23
Recently planted sites – 296
Wider environment – 183
Total: 502
Confirmed Findings (Cumbria)
• Nursery Sites – 0
• Recently planted sites – 9
• Wider environment – 0
• Total: 9

53. Disease Status
28 May 2013
Confirmed Findings (UK)
•
•
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Nursery Sites – 23
Recently planted sites – 296
Wider environment – 183
Total: 502
Confirmed Findings
(Northumbria)
• Nursery Sites/Recently
planted sites – 3
• Wider environment – 1
• Total: 4

54. Proposed Map of
Important Ash Locations
Ash in Northumberland
Ash in Cumbria
Source: Interim Chalara Control Plan
Defra, 6 December 2012

55. Ancient Ash Woodlands in
Northumberland
Source: Brown, K. 2006. A survey of the extent and condition of Ancient Woodlands in
Northumberland. Northumberland Native Woodland Project/Forestry Commission

60. Action on Ash
• National Strategy
– Latest update, late March 2013
– Focus on research, monitoring, diagnosis
– Regulations and international partnerships
– Still gather science information/exploring options
for management/containment
– Encourage local action
• Community Action and Citizen Science
– Range of programmes being developed

61. Research on Ash
Source: Jo Clark, Earth Trust

62. Resistance
Highly susceptible
Fraxinus excelsior
Fraxinus angustifolia
Fraxinus niger
Moderately susceptible
Least susceptible
Fraxinus ornus
Fraxinus pennsylvanica
Fraxinus americana
Fraxinus mandschurica
Also promising signs of some resistance in populations of F.
excelsior in Europe; evidence 1-2% of ash population in
Denmark may show some level of useful resistance

63. Research on Intensive Treatments
Source: O’Callaghan 2013

64. Citizen Science
• A range of great projects are underway!
• AshTag – identification/report suspected cases
• Phone app
• University of East Anglia
• OPAL - Tree Buddy Initiative
• Natural History Museum
• www.opalexplorenature.org
• Treezilla – map of British trees/ecosystem benefits
• Open University
• www.treezilla.org
• Launch 14 June 2013
• Other projects
• Woodland Trust
• Tree Council
• Local Wildlife Trusts

65. Roadside Survey of Ash (Fraxinus excelsior)
A66 Penrith to Keswick, 11 Nov 2012
St John’s in the Vale
Lake District, Cumbria
Watendlath
Borrowdale

66. Continuous band of common ash
saplings (natural regeneration)
on north side of A66
Photo: E.R. Wilson 2012
View looking east from
near Scales, Cumbria

67. Roadside Survey of Ash (Fraxinus excelsior)
A66 Penrith to Keswick, 11 Nov 2012
West
Potential disease spread from East
East
14
Ash Density Score
12
10
8
6
4
2
0
27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
Keswick
8
7
6
5
4
3
A66/M6 Junction 40
Continuous distribution, high density
Ancient Ash Trees
Borrowdale
1
Penrith
Distance in Kilometres
A66/A591 Junction
2
Continuous distribution, moderate density
Discontinuous distribution, low density
No ash present

68. Conclusions
• Ash is among the most important native species in Britain
– Ecological, biodiversity, landscape, cultural, economic values
• Ash dieback is one of several very nasty diseases affecting trees in Britain at
the current time
• Ash dieback disease is spreading into the “wider environment” mainly
from the south and east of England
• There are many uncertainties about the disease and its rate of spread
• At best, we may be able to slow the disease, but based on current
information we are likely to lose many mature trees, in time
• We expect most ash populations to be affected over the next few years but
a small percent of trees will likely to be resistant/tolerant
• Research is a key element of future strategies:
– Ecological and successionary impacts, and landscape impacts
– Genetics and ecological research
– Novel plant health treatments for individual (high value) trees, using new
technologies and fungicides

69. Conclusions
• Opportunities for citizen involvement/partnership
– Mapping the high value locations – cultural/ecological
values
– Monitoring – professionals and citizen engagement
– Science to inform future action – initiated and pending
– Cultural and Arts Projects – Celebrating the Age of Ash

70. Further Information
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Forestry Commission
– www.forestry.gov.uk/chalara
– 08459 33 55 77 (open 8am - 6pm every day)
– plant.health@forestry.gsi.gov.uk
Food and Environment Research Agency (FERA)
– www.fera.defra.gov.uk
TreeWatch - Sylva Foundation
– www.sylva.org.uk/treewatch
AshTag
– http://ashtag.org/
Future Trees Trust
– www.futuretrees.org
Woodland Trust
– www.woodlandtrust.org.uk

71. Ash pollard
St John’s in the Vale, Cumbria
Photo: E.R. Wilson 2012

72. Ash Dieback Disease Public Talk
Acknowledgements
My thanks to the following colleagues: Barnaby Wylder, Forestry
Commission; Kate Holl, Scottish Natural Heritage; Mari Jonsson, Swedish
University of Agricultural Sciences; Sharon Rodhouse; Jo Clark, Earth Trust
Further Information
Ted Wilson
Silviculture Research International
45a King Street, Penrith, Cumbria CA11 7AY
www.silviculture.org.uk
First presented: 30 05 2013
This version: 1.0, 30 05 2013