Tree Health & Biosecurity

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1 Tree Health & Biosecurity Dr Anna Brown Head of Tree Health and Contingency Forestry Commission England CAAV/RFS 31 October 2018

2 What is the issue? 17 in 13 years 5 in 32 years

3 Why such an increase? Increased demand for a wide range of plants and trees Increased demand for instant impact trees = increased risk

4 Why such an increase? International trade of live plants is estimated to be responsible for 70% of tree pests entering the US. (Liebhold et al. 2012) Ships have increased in capacity with 8 million containers arriving annually in the UK.

5 Global Trade it s not just plants Wood and wood products.. and even furniture = unwelcome guests 2017: 200+ interceptions of non-compliant material

6 Plus an added complication Climate Change Changing environment Stressed trees Increased vulnerability Warmer temperatures Increased probability of certain P&Ds establishing Increased risk

7 PATHOGENS causing DISEASES Fungi e.g. Ash dieback Phytophthora spp. e.g. Ramorum Bacteria, viruses e.g. Xylella fastidiosa PESTS Insects e.g. Oak processionary moth, Asian longhorn beetle Current issues and future threats DISORDERS e.g. (Acute) oak decline 7 31/10/2018 Biosecurity & Forestry

8 Chalara dieback of Ash Pathogen/ distribution Hosts Impacts How did it get here/ rate of spread Current/ proposed actions Hymenoscyphus fraxineus originates from Asia Now widespread in Europe and the UK. All species of ash affected; European ash highly susceptible. Recent findings on other members of the Oleaceae family. European ash trees are usually killed but some potentially tolerant trees. Increased incidence of secondary pathogens (e.g. Armillaria) - increased H&S risks Many species rely on ash - biodiversity impacts. Links with planting material and associated leaf litter/growing medium. Spores are produced in the leaf litter and are airborne can travel long distances - evidence of wind blown spores from the continent. Import and movement restrictions on ash. Task group established to manage health & safety aspects. Research including in to tolerant trees/future breeding. Good Biosecurity Distribution of Ash Dieback at 04 Sep Wilting leaves usually seen in spring and early summer

9 Managing ash dieback in woodlands If you have ash plan now Young trees (<25 years) - Consider the management at stand level Older trees (>25 years) - Consider the management at individual tree level If 50% of crown affected - fell and restock If trees are showing basal lesions - fell within 3 years Retain any potentially tolerant trees Remember that in the majority of cases you will still need a felling licence

10 Ash dieback H&S and Planning Also recent FISA Guidance Ash dieback and secondary Armillaria infection is causing high levels of tree and crown mortality and reduced fibre strength at felling height Trees, particularly in areas high levels of access, need to be carefully monitored Special care is required during felling operations - infected trees may react unpredictably and risk to chainsaw operators is increased Where possible, the best control measure is to use mechanical harvesting equipment where the operator is in a protective cab

11 Ramorum dieback Pathogen/ distribution Host Impact How did it get here? Rate of spread? Phytophthora ramorum is an oomycete, present in parts of the UK - mainly west. Wide range of ornamental and tree hosts. Particularly damaging to larch and sweet chestnut. Large numbers of Japanese larch trees have been killed. Other hosts e.g. rhododendron and sweet chestnut may also suffer dieback or bleeding lesions (beech) Trade of plants (such as rhododendron), contaminated growing medium, and natural dispersal. Rapid spread by wind or rain (peak Autumn), jumps via soil attached to shoes/vehicles/kit. Distribution of Ramorum as at October 2016 Current and proposed actions Surveillance to detect new infections. Statutory felling of sporulating hosts to reduce inoculum and slow the spread and minimise the disease intensity. Processing and movement licences are required for affected material. Research management, new hosts Good Biosecurity Dead in groups in the stands

12 How do we detect it?

13 Aerial surveys

14 How does it kill larch?

15 Field and laboratory tests Infected Healthy Healthy - reaction 15 31/10/2018 Footer text

16 Why statutory felling?

17 12 months later..

18 Oak Processionary moth Pest/ distributio n Hosts Impacts How did it get here? Rate of spread Current/ proposed actions Thaumetopoea processionea originated from central/southern Europe. UK distribution restricted to parts of southern England. Primarily a pest of oak (Quercus). Defoliation, which may weaken or kill trees following successive years of attack. Human/animal health hazard. Most likely as eggs on imported trees. Uncontrolled spread ca. 5km/year. Protected zone status import and movement controls - new regulation Surveillance (including pheromone trapping) - new infections and population levels. Chemical spraying and manual nest removal - spread slowed -ca. 1.5km/year. Public awareness campaigns to encourage reporting of the moth and discourage contact - Good Biosecurity Distribution of OPM in Aug 2016 Caterpillars have urticating hairs that pose human and animal health risk

19 OPM Resource toolkit 19 31/10/2018 Biosecurity & Forestry

20 Acute Oak Decline Disorder/ distribution Hosts Impact How did it get here? Rate of spread Current/ proposed actions A complex association of native organisms e.g. Agrilus biguttatus and bacterial spp. Mainly distributed in the midlands and SE England. A serious disorder of oaks - mainly mature trees. Can cause mortality over a period of years, although not all infected trees die. Reduction in oaks would have significant social and biodiversity impacts. Unknown - present for at least years Spreads from tree to tree gradually, but can spread more rapidly via infected planting material. Appears to be moving north and west in England limited by Agrilus? Research into causes and management of the disorder. Good silvicultural practice to help reduce spread and protect uninfected areas e.g. selective removal of trees, good planting practice. Good Biosecurity - good hygiene, destruction of infected material. Action Oak Initiative raising funds for research and monitoring - Distribution of AOD at March 2016 Bleeding cankers

21 Asian longhorn beetle Pest/ distribution Hosts Impacts How would it get here? Anoplophora glabripennis originates in Asia. Occasional interceptions and a previous single outbreak in Kent. A wide range of native trees. Larvae tunnel inside wood, causing structural weakness and providing entry points for diseases. Larvae moved from Asia in poorly treated wood packaging material. Rate of spread Current/ proposed actions A few hundred metres a year would be typical for a well established outbreak. Removal and chipping of the infested tree(s) or WPM Tree felling in Kent has controlled the UK outbreak. Checking of WPM at ports for compliance with International Standard for Phytosanitary Measures 15 (ISPM15). Good Biosecurity Adult female Asian longhorn beetle from the side Melody Keena, USDA Forest Service, Bugwood.org Cross section through trunk showing larval boring holes Joe Boggs, Ohio State University, Bugwood.org

22 Future threats? UK Plant Health Risk Register contains over 1000 Pests and disease Pinewood nematode Bronze Birch Borer Citrus Longhorn Beetle Eight-toothed European Spruce Bark Beetle Elm Yellow Phytoplasma Emerald Ash Borer Pinewood Nematode Pine Processionary Moth Xylella fastidiosa Bronze Birch Borer Emerald Ash Borer

23 Xylella fastidiosa Pathogen/ distribution Hosts How would it get here? Impacts How quickly does it spread? Current and proposed actions Xylella fastidiosa is a bacterial pathogen native to the Americas - introduced to parts of Europe. Xylella has a vast host range including olives, vines, lavender and ash, elm and plane. Most likely to arrive on planting material. Bacteria block the xylem vessels leading to dieback, leaf scorch and in some cases mortality. Massive economic and social impacts e.g. removal of ancient olive trees in Italy, nursery movement restrictions for 5 years. Local spread by xylem feeding insects, longer distance via trade of asymptomatic plants. Destruction of infected plants and spraying of vectors. EU legislation, all hosts within 100 metres destroyed, strict movement controls within 5KM of outbreak. Import controls of high risk hosts. Leaf scorch of Platanus occidentalis (American sycamore) Polygala myrtifolia infected by X. fastidiosa in Corsica.

24 Underpinning Legislation and Policies + = Directive 2000/29/EC Directive 2005/17/EC Plant Health Forestry Order year Environment Plan Tree Health Resilience Strategy

25 Environmental Goals The government s new 25 year plan for improving the environment recognises calls for a new approach that puts the environment first The Tree Health Resilience Strategy vision is to: Build the resilience of England's trees, woods and forests Enhance the benefits trees provide, by mitigating and minimising the impact of pests and diseases, and Improve the capacity of our trees to adapt to changing pressures What can you do? 25

26 26 Keep it Clean!

27 Keep it Clean!

28 Picture courtesy of Observatree Keep it Clean!

29 Is there any point? YES! 29

30 Biosecurity resources/training modules: Resources Pest and disease information Forest Research - Observatree - UK Plant Health Portal: planthealthportal.defra.gov.uk And finally. Tell us if you spot ill health in trees via Tree Alert: