Emerging Pests and Diseases – A Global Crisis ?
Sarah GreenForest ResearchNorthern Research Station
30/11/20112
Introduction
Global examples of emerging pests and diseases
Six new emerging tree pathogens in Britain since 2000
Phytophthora lateralis as an example of emerging pathogen
Plant trade an important pathway, so what can/should be done ?
30/11/20113
Examples from around the globe……
30/11/20114
Chestnut blight
introduced into North America from China/Japan
An estimated 4 billion American chestnut trees killed since 1910
30/11/20115
Dutch elm disease (Ophiostoma novo-ulmi)
From eastern Asia
Devastated elms in Europe and North America since 1960s
Introduced to UK on elm logs imported from Canada
Spread globally through timber trade
30/11/20116
Phytophthora ramorum on tanoak in California (late 1990s)
Affecting hundreds of kms
of coastal forest in California –
killing 100% of all tanoaks in some areas
Introduced from an unknown location through the nursery trade
30/11/20117
Emerald Ash Borer (Agrilus planipennis)
Native to Asia
Introduced to North America in 2002
Solid wood cargo packaging implicated as pathway
Spread through eastern USA and Canada –killed over 20 million ash trees since 2002
30/11/20118
Ceratocystis platani on Platanus spp. in Europe
Introduced from North America on wood products during WWII
Recent increased spread amongst European countries via nursery trade
30/11/20119
Pitch pine canker (Fusariumcircinatum)
in Spain since late 2000’s
Origin probably Central America
Impact on Pinus radiata in N. Spain but European pine spp. at risk
Spread internationally via transport of contaminated seed and seedlings
30/11/201110
Pine wood nematode(Bursaphelenchus xylophilus)in Portugal since 1999
Native to N. America
Spread to Asia and Europe through trade in woodProducts
46 million m3
pine lost in Japan due to disease
Pine wilt disease now spread across whole of Portugal
30/11/201111
Puccinia psidii on Myrtaceaeincluding Eucalyptus
Native to South and Central America
Spread to Florida then Hawaii
Spreading in Australia since April 2010 -
over 100 potential
hosts to infect in Australia
Trade in live plants implicated in disease spread
30/11/201112
The current situation in Britain……
30/11/201113
Phytophthora austrocedraeon Lawson cypress and Nootka cypress
From ?
Associated with widespread decline of Austrocedrus chilensis in Patagonia(mal del cipres)
30/11/201114
Phytophthora lateralis on Lawson cypress
From SE Asia
Devastated Lawson cypress in Oregon/California since 1950s
Impact in Britain on amenity plantings
30/11/201115
Phytophthora ramorumon larch
Host jump !. Which host next ?
From Eastern Asia via Europe ?
Removal of larch from all FC plantations in SWEngland
30/11/201116
Phytophthora kernoviaeon vaccinium
From Asia via New Zealand ?
Potential impact on native heathland
vegetation
30/11/201117
Dothistroma Needle Blighton pines
From where ?
384 subcompartments
of SPpositive for DNB in 2011
30/11/201118
Pseudomonas syringae pv. aesculi on horse chestnut
From India
In 2007 survey (FR) symptoms on:70% of trees in England36% of trees in Wales42% of trees in Scotland
Further spread in Europe
30/11/201119
Phytophthora lateralis is a fine example of what happens when a pathogen leaves home……
30/11/201120
Phytophthora lateralis
Main host is Lawson cypress – mainly root pathogen
First appeared in Pacific North West of USA in 1920s –
now major
pathogen of Lawson cypress across native range
Recently isolated from old-growth Chamaecyparis forests in Taiwan
Does not cause any significant damage in Taiwan
Has co-evolved with its host
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Global occurrence of P. lateralis
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P. Lateralis outbreaks in UK
30/11/201123
‘UK variant’
found at Balloch
and Kilmaronock-
genetically and phenotypically
unique
‘Oregon variant’
found in Oregon, France, NI, Scotland and England
‘Taiwan variant’
found in Taiwan
Balloch
TGTTTTACATTCATGGGCTATTCCCTCATTAGGTATTAAATTAGATGCTTGTCCAGGACGKilmaronock
TGTTTTACATTCATGGGCTATTCCCTCATTAGGTATTAAATTAGATGCTTGTCCAGGACG Greenock
TGTTTTACATTCATGGGCTATTCCCTCATTAGGTATTAAATTAGATGCTTGTCCTGGACG RoukenGlen
TGTTTTACATTCATGGGCTATTCCCTCATTAGGTATTAAATTAGATGCTTGTCCTGGACG Oregon
TGTTTTACATTCATGGGCTATTCCCTCATTAGGTATTAAATTAGATGCTTGTCCTGGACG France
TGTTTTACATTCATGGGCTATTCCCTCATTAGGTATTAAATTAGATGCTTGTCCTGGACG Taiwan
TGTTTTACATTCATGGGCTATTCCATCATTAGGTATTAAATTAGATGCTTGTCCTGGACG
P. Lateralis : three
‘variants’
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How did P. lateralis get here ?
Two nursery interceptions in 2011 on:
Thuja occidentalisLawson cypress
Plants imported from France and The Netherlands
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How did P. lateralis get here ?
Two P. lateralis outbreaks adjacentto garden centres
30/11/201126
Global trade in plant material
Strong evidence to link treepest and disease outbreaks to global trade in plant material
Increased number of tree pest/pathogen interceptions in the UKFera/FC data
30/11/201127
Montesclaros
Declaration !
“As scientists studying diseases of forest trees, we recognize that the international trade of plant material is increasing the risks to
forest health
worldwide. The evidence for this view is based on the recent, unprecedented rise in numbers of alien pathogens and pests emerging in natural
and planted
forest ecosystems in all parts of the globe. We thus propose a phasing out of
all trade in plants and plant products determined to be of high risk
to forested
ecosystems but low overall economic benefit.”