ash trees and their future in britain
DESCRIPTION
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.TRANSCRIPT
Ash Dieback Disease Public Talk
Ash Trees and their Future in Britain
Ted WilsonSilviculturist
Jubilee InstituteRothbury, Northumberland30 May 2013
First presented: 30 05 2013This version: 1.1, 31 10 2013
Outline for Talk
• 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
25th July 2012Which tree species to plant for a changing
environment
Biosecurity: Chalara is the latest on a growing list of pests/pathogens
Source: Forestry Commission 2012
Recent arrivals
2010 2011
2005
20062002
2009
2003
2002
20112012
2012
Decade of Contagion?
Source: Barnaby Wylder 2013
Ash distribution across Europe
Source: EUFORGEN
Ash in the UK
Source: Forestry Commission 2013
Ash in the UK
Source: Forestry Commission 2013
Ash in the UK
Source: Forestry Commission 2013
Foliage and Reproduction
Ash – a fine timber tree
Uses for Ash
The World Ash TreeWagner – The Ring Cycle
Bryn Terfel as Wotan, holding the Ash SpearRing Cycle, Royal Opera, Covent Garden, 2012
Ash in Cumbria – the Gosforth Cross
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
Ash is a common speciesin parks and townsSt. Andrew’s Church
Penrith
Weeping ashSt. Andrew’s Church
Penrith
Physiographyof Cumbria
Borrowdale
Source: Ratcliffe, Lakeland, New Naturalist
Woodlands and trees in Borrowdale, Cumbria
Key components of the Atlantic oakwoodsin Borrowdale, Cumbria
Ancient and recent secondary woods containing a range of woodland types1
Complex of woodland types:Oak-birch woodland (W17)
Oak-hazel woodland (W9, W11)
Hazel-ash woodland (W9)
Ash-wych elm woodland (W9)
Alder-ash woodland on mineral soil (W7)
Alder-willow woodland on organic soil (W1-6)
Birch woodland (W4, W11,W17)
Hazel woodland (W?9)
Sallow scrub (W?1-6)
Holly and/or rowan scrub (W??)
Beech-oak woodland (W14, W15)
1Coding from National Vegetation Classification (Rodwell 1991)Source: G.Peterken
Slide
Biodiversity: ButterfliesSelection of species associated with western oakwoods
Pearl-bordered fritillary
Photos from Millennium AtlasSunart
Dartmoor woods
Chequered skipper
Brown hairstreak
Green hairstreak Silver-washed fritillary Purple emperor
High brown fritillary
BladderseedPhysospermum
cornubiense
Cow wheatMelampyrum pratense
Irish spurge Euphorbia hyberna
Bastard balmMelittis melissophyllum
Pictures: G. Peterken
Biodiversity: Specialised western vascular plants associated with Atlantic oakwoods
Radula voluta Plagiochila atlantica
Isothecium myosuroides
Adelanthus descipiens
Biodiversity: Mosses and liverworts
The lower row shows examples of species restricted to an oceanic climate (‘Atlantic bryophytes’). Moisture and light levels are key habitat determinants.
Photos from Porley and Hodgetts, New Naturalist 97Source: G.Peterken
Biodiversity: Lichens
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, 1974Source: G.Peterken
Centre for oceanic epiphytic lichensParticularly associated with large trees and glades
Ash woodlandGreat Mell Fell, Cumbria
Lichens and mosses on ashGreat Mell Fell, Cumbria
Pollarded ash trees, Watendlath
Pollarded trees in Borrowdale
Ancient Ash Pollards on the Sognefjord, Norway
Source: Kate Holl, Scottish Natural Heritage
Fraxinus excelsior pollards Seathwaite Wood
Ash pollard Near Rosthwaite, Borrowdale, Cumbria Photo: E.R. Wilson 2012
Ash pollard Near Glaramara, Borrowdale, CumbriaPhoto: E.R. Wilson 2012
Ash pollard St John’s in the Vale, Cumbria E.R. Wilson 2012
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
Forestry Commission
How to Identify Chalara fraxineaon ash trees
YouTube Video
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
Signs of disease
Source: Forestry Commission 2012
Trace Forward: Newly planted seedling showingsigns of ash dieback disease (Chalara fraxinea) Photo: Sharon Rodhouse 2012
Wider Environment: A mature ash tree with Signs of ash dieback disease (Chalara fraxinea)
Photo: Sharon Rodhouse 2012
Source: Barnaby Wylder, Forestry Commission 2012.
Ash Dieback in Denmark
Photo: Mari Jonsson, Swedish University of Agricultural Sciences
Ash Dieback in Sweden
Ash Dieback Locations6 November 2012
Source: Forestry Commission
Wider Environment
Newly Planted/Nurseries
Source: Forestry Commission
Ash Dieback Locations22 November 2012
Wider Environment
Newly Planted/Nurseries
Source: Forestry Commission
Ash Dieback Locations18 February 2013
Wider Environment
Newly Planted/Nurseries
Source: Forestry Commission
Ash Dieback Locations28 May 2013
Wider Environment
Newly Planted/Nurseries
Data: Forestry Commission 2012-2013
Graphic: AshStat/Silviculture Research International © 2013
Confirmed reports of ash dieback disease (Chalara fraxinea) in Britain 1 November 2012 to 28 May 2013
Nov 2012 Dec 2012 Jan 2013 Feb 2013 Mar 2013 Apr 2013 May 2013
0
100
200
300
400
500
600
0 20 40 60 80 100 120 140 160 180 200
Reports
Days from Start of Outbreak
Nursery Sites Recently Planted Sites
Wider Environment Total
Recent planting
Source: Barnaby Wylder, Forestry Commission 2012.
Disease Status 28 May 2013
Confirmed Findings (UK)• 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
Disease Status 28 May 2013
Confirmed Findings (UK)• 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
Proposed Map of Important Ash Locations
Source: Interim Chalara Control Plan Defra, 6 December 2012
Ash in Cumbria
Ash in Northumberland
Source: Brown, K. 2006. A survey of the extent and condition of Ancient Woodlands in Northumberland. Northumberland Native Woodland Project/Forestry Commission
Ancient Ash Woodlands in Northumberland
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
Research on Ash
Source: Jo Clark, Earth Trust
Resistance
Highly susceptibleFraxinus excelsior
Fraxinus angustifolia
Fraxinus niger
Moderately susceptibleFraxinus ornus
Fraxinus pennsylvanica
Least susceptibleFraxinus 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
Source: O’Callaghan 2013
Research on Intensive Treatments
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
Roadside Survey of Ash (Fraxinus excelsior) A66 Penrith to Keswick, 11 Nov 2012
Lake District, Cumbria
Borrowdale
St John’s in the Vale
Watendlath
Continuous band of common ash saplings (natural regeneration) on north side of A66
View looking east from near Scales, CumbriaPhoto: E.R. Wilson 2012
0
2
4
6
8
10
12
14
27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
Ash
De
nsi
ty S
core
Distance in Kilometres PenrithA66/M6 Junction 40
KeswickA66/A591 Junction
No ash present
Continuous distribution, high density
Continuous distribution, moderate density
Discontinuous distribution, low density
West East
Ancient Ash TreesBorrowdale
Roadside Survey of Ash (Fraxinus excelsior) A66 Penrith to Keswick, 11 Nov 2012
Potential disease spread from East
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
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
Further Information
• Forestry Commission
– www.forestry.gov.uk/chalara
– 08459 33 55 77 (open 8am - 6pm every day)
• 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
Ash pollard St John’s in the Vale, Cumbria Photo: E.R. Wilson 2012
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 WilsonSilviculture Research International 45a King Street, Penrith, Cumbria CA11 7AY
www.silviculture.org.uk
First presented: 30 05 2013This version: 1.0, 30 05 2013
Ash Dieback Disease Public Talk