ash dieback presentation essentaksterfte nl april 2015
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Department of Geosciences and Natural Resource Management
Infomeeting Essentaksterfte, Haren, NL 14 april 2015
Experiences of ashdieback in Denmark
Senior adviser Iben Margrete Thomsen
Department of Geosciences
and Natural Ressource Management
University of Copenhagen
Essentaksterfte / Ash Dieback
Department of Geosciences and Natural Resource Management
Ash dieback is a fungal disease (schimmelziekte).But does it kill the ash trees ?
Chalara fraxinea
Hymenoscyphus pseudoalbidus
= Hymenoscyphus fraxineus
Life cycle of the fungus (schimmel)
- A sign of desperation
Noodgroei
High risk of wooddiscolouration
Department of Geosciences and Natural Resource Management
Epicomic shoots on branches and stems
NL Febr. 2015
Department of Geosciences and Natural Resource Management
Sted og datoDias 7
Necroses of bark and wooddiscolouration
Department of Geosciences and Natural Resource Management
Department of Geosciences and Natural Resource Management
Hymenoscyphus fraxineus Origin: Asia on Fraxinus mandschurica
Ref: McKinney et al (2014)
How
?
Amongst the first to die are pendulate ashTreuressen
Department of Geosciences and Natural Resource Management
Sted og datoDias 9
Amongst the first to die are pendulate ashTreuressen
Department of Geosciences and Natural Resource Management
Essentaksterfte / Ash Dieback
Katastrofal im Wald / A disaster in forests
In der Stadt /offenen Landschaft weniger fatal
Less fatal in towns and the open landscape
Department of Geosciences and Natural Resource Management
Department of Geosciences and Natural Resource Management
2007 2009 2011
2013 Sommer 2013 Winter
See also
slides at the
end
Fraxinus in Kopenhagen
Department of Geosciences and Natural Resource Management
1.400 Strassen-bäume
8% des Bestands
Überwiegend F. excelsior
50 % später als 2000 gepflanzt
Nicht seit 2012
F. excelsior AlleeKeine SymptomeTriebe gesundMarts 2014
Possible explanations
• No honey fungus / honingzwam (Armillaria)
• No ash bark beetles / Essenbastkever(Hylesinus)
Department of Geosciences and Natural Resource Management
Reduzierte Infektion / Reduced infection
• Laubentfernung / removal of leaf litter
• Eher Trocken = weniger Fruchtkörper
• Drier conditions = fewer fruitbodies
Department of Geosciences and Natural Resource Management
Stadt- und Straßenbäumen / City and road trees
Department of Geosciences and Natural Resource Management
• Viele junge Eschen sterben wahrscheinlich.
• Many young ash trees will probably die.
Stadt- und Straßenbäumen / City and road trees
Department of Geosciences and Natural Resource Management
• Alte Eschen sterben manchmal auch.
• Old ash trees die occasionally.
Aber viele alte Esche überleben
Department of Geosciences and Natural Resource Management
But plenty of old ash trees survive
Department of Geosciences and Natural Resource Management
Ash dieback outside of forests is an aesthetical problem, not a matter of survival. Stay calm.
2013
Saved at the last minute
This huge ash tree in a churchyard was scheduled for fellingin 2013 due to ash dieback. Instead they did a crownpruning and kept the tree.
The old ash will probably live for many years with the disease, showing dieback symptoms in some years and less in others.
Repeated pruning every 5 or 10 years will deal with any safetyconcerns from dead branches.
Department of Geosciences and Natural Resource Management
2014
Nicht zu fruh fällen / Don’t fell too soon
Eschen in Städten, längs Straßen und in der Landschaft so lange wie möglich bewahren (Verkehrssicherheit beachten).
Preserve ash trees in cities, along road and in the landscape for as long as possible (keep safety in mind).
Department of Geosciences and Natural Resource Management
Die Bäume sollten erst gefällt werden, wenn sie absterben,
oder ihre Krone über 2-3 Jahre nicht wieder regenerieren.
Department of Geosciences and Natural Resource Management
The trees should be felled when they die, or when they do not regenerate their crowns 2-3 years in a row.
Zukunft der Eschen / Future of ash ?
Resistente Eschen anwenden
- wenn sie verfügbar sind.
Use resistant species / clones
- if or when available
Department of Geosciences and Natural Resource Management
Find and clone healthy ash
Department of Geosciences and Natural Resource Management
Test resistance against disease
Artificial inoculation with
H. fraxineus
Department of Geosciences and Natural Resource Management
Seed orchard with controlled crossings
Department of Geosciences and Natural Resource Management
Conclusions
• Please do not panic !
• It is not like Dutch Elm disease, felling treesfast does not prevent spread of fungus.
• Removing fallen leaves is much better.
• Sick trees can live many years and look OK, particularly if you remove dead branches.
• 1-2 % ash are resistant, look out for them.
• Use Fraxinus ornus or perhaps Fraxinusamericana / pennsylvanica or even Fraxinusmandschurica.
• .
Department of Geosciences and Natural Resource Management
2007
IMT, University of Copenhagen
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IMT, University of Copenhagen
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IMT, University of Copenhagen
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IMT, University of Copenhagen
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IMT, University of Copenhagen
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2012
IMT, University of Copenhagen
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IMT, University of Copenhagen
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2013
IMT, University of Copenhagen
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IMT, University of Copenhagen