Governing Tree Disease
Epidemics:
Some policy lessons from
the ramorum outbreak
Clive Potter
Centre for Environmental Policy
Imperial College London
© Imperial College London
The Story to Date

An evolving story, in which plant health
authorities have struggled to keep up with a
disease that has expanded its host range;

Initial focus on eradication within the nursery
trade has given way to a broader strategy of
attempted containment focussed on woodland,
historic gardens and commercial forestry
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Summer 2001
P.ramorum pathogen
first identified on
nursery stock
2003
Discovery of ‘new’ P.
kernoviae pathogen in
Cornwall
2008
P.k pathogen identified
in open heathland
2009
Discovery of P.r on
Japanese larch in SW
2011
Confirmation of P.r. on
European larch
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November 2002
Government puts in place
emergency measures
February 2003
Interim Programme Board
established
March 2009
New funding for R.ponticum
clearance and other measures
Spring 2011
Larch clearance begins on FC
land
November 2011
New Tree Health and Biosecurity
Action Plan announced
The policy challenge
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
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Complicated science and an evidence base that
has co-evolved with the disease system
Many stakeholders involved, some of whom
may be ignorant, apathetic or misinformed
Presence of difficult to navigate conflicts
between commercial interests and the wider
public good
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We’ve been here before


The 1970s Dutch Elm Disease outbreak, while
biologically v different, is an obvious point of
historical reference;
In this case, delays in identification, Treasury
reluctance to fund, confusion regarding liability
and the decision to devolve management onto
poorly resourced local authorities fatally
compromised the policy response
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Snapshots of the UK Dutch Elm Disease Epidemic
1968
•Mounting public reports
of dead and dying elms
reach the Advisory
Service at the Forestry
Commission
•DED outbreaks identified
in three locations in
southern England
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1970
1972
• Initial government
response to outbreak is a
voluntary sanitation felling
campaign
•First FC DED survey published
shows dramatic extent of DED
•Criticism of how outbreak
being handled lead to calls
for legislation
• 1973: Paper identifying origin
of aggressive form published in
Nature
•October 1971: DED (Local
Authorities) Order 1971
gave powers to 50
authorities to enter land and
inspect elm trees and to
take steps to prevent the
spread of the disease
•Idea of a regional cordon
sanitaire proposed for southern
England
• DED (LA) Order 1971 revoked
as deemed to be ineffective
• 1974: Order restricting
movement of diseased elms
introduced and (LA) Order
reintroduced
1979
• Meanwhile, DED
continues its relentless
northwards spread …
Presence of live
infected elm trees
represented in yellow.
Red indicates dead
elm trees present.
Black shading shows
that over 60% of elm
population had been
wiped out by 1979
Lessons to be Learned
By comparison, overall management
of ramorum outbreak has been better:




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rapid, cross-cutting institutional response
extensive stakeholder involvement
excellent work of inspectors on the ground
But subsequent spread confirms the cardinal
lesson of DED: that tree diseases are very
difficult (and costly) to contain once
established in the wider environment ...
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The Bigger Picture
•
•
•
Tree diseases threats to rural landscapes, urban
trees and ecosystem services likely to grow with
increasing volumes of horticultural trade;
But WTO disciplines and Single Market imperatives
mean that scope for restricting (as against better
regulating) this trade is v limited;
So, even with ever more refined risk assessment
tools, improved inspections and better surveillance,
policymakers typically forced on to the back hoof
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Future Prospects
•
•
•
On other hand, recent review of the EU’s Plant
Health Regime has brought limitations of the plant
passporting system and other systemic weaknesses
to attention of DGSANCO;
Defra’s new Tree Health and Plant Biosecurity
Action Plan suggests plant health issues may in the
ascendancy;
First inklings of a broader public debate about the
hidden economic costs of the global trade in plants?
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