Tree Health and Plant Biosecurity

Third written evidence submitted by Defra

Introduction

This note sets out Defra’s responses to the questions identified by the Committee following its Evidence Session with the Defra Chief Scientific Adviser, Professor Ian Boyd, Fera and the Forestry Commission. It contains input from the Forestry Commission and Fera.

1. Wood fuel and wood products

a) What assessment has Defra made as to the risk of transferring Chalara fraxinea via wood for use as fuels, or as wood products? (If ongoing what is the timescale for its completion?)

The pest risk analysis completed for Chalara fraxinea, on which the public consultation during 2012 was undertaken, assessed the risk of wood and timber products as being medium, but on the basis of other non – sporulating forms of Chalara. The PRA states, "No information is available on the ability of the pest to persist in soil; other pests with a Chalara anamorph have been shown to be transmissible via soil or infected wood but these species are able to form resilient, long-lived spores which do not appear to be produced by C. fraxinea."

The outcome of the consultation into the PRA is at:

http://www.fera.defra.gov.uk/plants/plantHealth/pestsDiseases/documents/chalaraConsultationOutcome.pdf

Four out of the sixty eight respondents referred to the movement of ash wood as a potential pathway and sought reassurance that biosecurity measures would be introduced or at least considered to prevent or restrict the movements of timber from diseased areas. This was addressed in the interim Chalara Control Plan, and is covered in b) below.

Since then a French study, (Husson et al, 2012, Plant Pathology), has been undertaken on the potential for ash timber to transmit the disease. The study indicates that export of ash logs could represent a potential risk for spreading the disease, but at a much reduced level, and concludes that the available data do not support control of ash logs as a quarantine measure. This evidence suggests a much reduced level of risk.

b) What advice and/or regulation does Defra propose on limiting the movements of wood and wood products based on this assessment?

At this time, there are no restrictions on the movement of ash wood from other member states, and none is currently proposed on the basis of the available evidence.

The legislation continues to permit movements within Great Britain of all ash timber from sites with no confirmed Chalara fraxinea infection, which is now assessed, following the French study highlighted above, as posing a low risk of disease transmission. Although there are no specific measures on logs and firewood in the legislation, the general prohibition on spreading Chalara fraxinea means that movement is prohibited within Great Britain of logs and firewood from woodlands and other sites with confirmed Chalara fraxinea infection and which have been served with a statutory Plant Health Notice.

The legislation continues to permit imports of sawn ash timber from certain Third countries under existing regulations against the forestry pest Emerald Ash Borer (EAB). These require the material to be accompanied by official phytosanitary (plant health) certificates declaring that the material either originated in areas known to be free of EAB, or that the wood is bark-free (which addresses the Chalara risk as well) before entering Great Britain. Imported woodchips and bark of ash material have the same certification requirements as for wood, but the alternative to originating in an area of pest freedom is that the material has been processed into pieces of not more than 2.5cm thickness and width.

A ban on timber movement from other EU countries was considered, but was not taken forward for a number of reasons.

· To justify a ban, we would have to prove that the trade in timber presents a high level risk of transmitting the disease. The evidence does not indicate this.

· In order to demonstrate equivalence with other Member States we were of the opinion that any measures taken should recognise the prevalence of the disease in GB. Controls on movement of ash timber from GB would have been needed to reflect the controls of exports from other Member States.

· As infected sites are present throughout GB, either as recent plantings or in the wider environment, we would not have been in a position to declare pest free areas for the export of untreated ash timber.

· A ban was considered to be disproportionate, and would adversely impact on woodland management, GB ash producers, and firewood merchants.

It should be noted that the bans on imports in both Northern Ireland and the Republic of Ireland were introduced on the basis that eradication of the disease from the whole island of Ireland remains feasible. No sites in the wider environment have been found to date in either of these two countries. The possibility of eradication justifies a higher level of precaution against the low risk of reintroduction through movements of wood.

c) What level of imports to the UK are there currently of ash products, including as an energy feedstock?

On 1 April 2009, due to the threat from the forestry pest Emerald Ash Borer (Agrilus planipennis), the EU introduced plant health landing requirements for wood of ash entering EU member states from countries where the pest is known to occur ie Canada, China, Japan, Mongolia, Republic of Korea, Russia, Taiwan and USA. The requirements specify that the imports of ash wood of must be accompanied by a phytosanitary certificate (a statement of plant health) issued by the relevant authorities in the country of export declaring that the material either originates in an area known to be free of Emerald Ash Borer or that it is squared so as to remove entirely the outer round surface. In the case of imported woodchips the material is also required to be accompanied by a phytosanitary certificate declaring that it either has originated in an area known to be free of the pest or that it has been processed into pieces of not more than 2.5 cm thickness and width.

Approximately 468 consignments of sawn wood of ash comprising of 15,500m3 of material enter Great Britain from the USA and Canada each year and all of these are subject to plant health inspections to ensure that they meet the stipulated landing requirements.

There are a number of firewood merchants which import ash wood into the UK from other Member States. The wood is well prepared and kiln dried, ready to burn, and represents no risk of transmitting the disease. Volumes are fairly small, with one of the largest companies importing only around 1,500 tonnes per year. As ash is not a regulated species, no detailed records of imports are collated.

d) What monitoring is done of such imports, including quality assurance to ensure that leaves and twigs which make a product a higher risk for transmitting Chalara are not imported?

Contamination with leaves and/or twigs is prohibited for ash material derived from third countries. On average, around 1% of consignments from third countries fail to comply with the landing requirements and therefore they are subject to remedial action such as re-export, destruction or in exceptional cases treatment. Ash timber imported into the UK from Non-EU third countries is all fully sawn and dimensioned to order, and is kiln dried. Given the 100% inspection it receives, the risk of Chalara being transmitted from this source is extremely small. There are no records of ash firewood currently being imported from third countries.

There are currently no specific phytosanitary requirements for C. fraxinea in the EC Plant Health Directive, thus there are no checks on, or data for imports from within Europe. However, there is no evidence of trade in ash logs for sawmilling, and imports are likely to be of a similar standard to those from third countries. Thus the risk from this source of Chalara transmission is estimated to be extremely low.

2. What was the UK research spend from 2008-09 to date on Chalara research, both by Defra and its agencies and by other research bodies and/or the horticultural industry? What joint work has been undertaken on this with bodies in other EU member states?

Chalara-specific research and analysis

Defra has funded epidemiological modelling work in 12/13 , conducted by Cambridge University in collaboration with Rothamsted Research, in response to the UK Chalara fraxinea situation. The team has developed and parameterised a small suite of models to address the following three aims:

1) The likelihood and risk of airborne incursion into the UK;

2) Predicted spread of Chalara in the UK and effects of mitigation strategies;

3) Risk-based weighted sampling for Chalara in the UK.

The models used provide probabilities for incursion, spread, effectiveness of control and effective location of future sampling, using the best available data or information to which the team have had access. The models are tools that integrate the current state of knowledge in order to predict outcomes. Defra will co-fund with BBSRC a programme of further epidemiological modelling, and associated biological "parameterisation", to inform policy and strategies for the management of the disease.

Defra will also co-fund with BBSRC research to characterise the genetics of Chalara 'strains', and development of rapid practical diagnostics, as well as molecular epidemiology to add to understanding of the biology, diversity and pathogenicity of the fungus.  In addition a number of statutory agencies, led by JNCC, have formed a partnership to pool money to fund priority research this financial year. Tenders are expected to be invited in January 2013 and funding for this work is expected to be in the range of £175 - £225k

Defra has conducted a preliminary assessment of the wider social, economic and environmental value of ash trees to develop understanding of how targeted, evidence-based and proportionate action to reduce and delay the spread of the disease could offer value for money, for taxpayers and society at large. Whilst any reduction in the rate of spread would bring wider benefits, Defra will also consider any costs associated with action, both public and private sector (which can often be implicit), and ensure that these are proportionate to what we think they can achieve.

Whilst Forestry Commission research spending specifically on Chalara to date has been nil Forest Research has been a member of the European COST action FRAXBACK since its start in May 2012. The aim of the FRAXBACK action is, through sharing and synthesis of available knowledge, to generate comprehensive understanding of the Chalara fraxinea dieback phenomenon, and to elaborate state of the art practical guidelines for sustainable management of the disease in Europe. This will allow us to make full use of the experience of other countries in dealing with the pest in the wider environment to inform our own policy decisions in GB.

In addition diagnostic techniques developed to address other pathogens have been able to be adapted and developed to significantly improve the rapid turn round of suspect ash samples during the recent intensive investigative exercise.

Though not strictly research, the Forestry Commission spent approximately £1m on surveillance during the recent rapid assessment exercise to determine the presence of Chalara in the wider environment. This forms an important part of the overall evidence base

Wider tree health and plant biosecurity research

The amount spent on plant health research has increased owing to the injection of £8m by Defra in support of the Tree Health and Plant Biosecurity Action Plan from 12/13 – 16/ 17, and the fact that FC have increased the proportion of their research budget to be spent on plant health

The Chalara science workshop (held on 13th December) identified priority areas for research in detection, aetiology, pathology, epidemiology, impacts, mitigation and adaptation and will be used to inform the new Defra Tree Health and Plant Biosecurity evidence plan and Phase 2 of the Tree Health and Plant Biosecurity Initiative under the Living with Environmental Change (LWEC) Partnership. Defra has committed a total of up to £4M from the Tree Health and Plant Biosecurity Action Plan funding to this LWEC initiative between 12/13 and 16/17.

The aim of the Tree Health and Plant Biosecurity Initiative is to generate new scientific knowledge to inform the development of innovative ways of addressing current and emerging threats to trees and woodland ecosystems from pathogens and pests. The initiative is intended to facilitate collaboration between specialists in tree or forest research and leading-edge scientists from the wider natural, biological, social, economic or other relevant research communities who have expertise which could be brought to bear on research in this area. The scope of the initiative includes trees in forest, woodland and urban environments and of commercial, environmental and social value, as well as related plant biosecurity.

Defra will also fund a pilot project this financial year to accelerate development of ObservaTREE - a Forest Research-led bid for EU Life+ funding to develop an integrated Tree Health Early Warning System using volunteer groups. The pilot project will focus on establishment and testing of Information Communications Technology infrastructure and developing a cadre of champions, who are linked to the communications network. This study is linked to the potential EUPHRESCO International Plant Sentinel Network, which will provide a wider international element and additional early warning. This would build on the current Fera-led project on ‘Future Proofing Plant Health’,

Defra is a funding partner in a potential EUPHRESCO transnational research topic on ‘diagnostics and risk management for plant health threats in wood chips and bark for bio-energy imported from other continents’.

Fera is conducting a review Australian and New Zealand plant biosecurity as part of their wider review on cost sharing in plant health. The objectives of this review are to consider the performance of the Plant Health Australia programme and the New Zealand system over the last 5 years to assess what has worked well and less well, why this is the case, and to what degree are any lessons learned transferable to the UK. This Fera project was commissioned with a view to providing a brief, rapid assessment of information available that can be fed into a larger review of cost sharing being considered for commissioning in 13/14

3. What advice was given to those importing, selling or planting ash trees in the period between first detection of Chalara in the UK in March and the ban on imports/movements coming into force on 29 October 2012? Were any ash plants imported in this period and, if so, were any infected plants detected in imports occurring in this period?

Details of this interception were published on the Food and Environment Research Agency website on 17 April 2012, and a pest alert on the situation regarding Chalara fraxinea was posted on the Forestry Commission website on 16 May (the chronology in the earlier note incorrectly identified this alert as being on the 3 April, which was the date Ministers were informed). The pest alert indicated that the risk of disease spread is most likely to be via the movement of diseased ash plants. Practitioners who have been involved with recent imports were encouraged to carry out inspections of their trees and report symptoms if found.

A Q&A was made available on the Forestry Commission website, and included the message "Be careful about the sourcing of, and the specification for, your plants. Keep good records of any imported stock, remain vigilant, inspect any recent plantings of ash, and report any suspicious signs to Fera or the Forestry Commission.

A number of meetings with industry representatives were attended by plant health officials from the Forestry Commission to provide them with the latest information, and suggest how plant movements might be better controlled in the future. The possibility of a ban on movement of ash plants was raised in these meetings.

A series of press releases shown in the table below provided updates to stakeholders as information about the disease progressed.

Defra	Government bans imports of ash trees	29 October 2012
Forestry Commission	Government restricts imports of ash trees to tackle disease	29 October 2012
Forestry Commission	Efforts stepped up to tackle disease of ash trees	24 October 2012
Defra	Government looking at banning imports of ash trees	4 October 2012
Forestry Commission	Government considers ban on ash tree movements	4 October 2012
FC Wales	Ash tree checks under way in bid to keep disease out of Wales	26 September 2012
Forestry Commission & Fera	Forestry Commission and Fera welcome call for moratorium on ash tree imports in bid to control disease	21 September 2012
Forestry Commission	Consultation launched on risk assessment for Chalara dieback of ash trees	7th September 2012
FC Scotland	Alert re-issued as ash tree disease found in Scotland	21 August 2012
Forestry Commission	Woodland biosecurity guidance published	1 August 2012
Forestry Commission	Alert for serious disease of ash trees	16 July 2012

The main trading period for ash trees is November – February and whilst it is unlikely there were imports after infection was detected it cannot be stated categorically that no trees were imported as ash is an unregulated genus with no notification requirements. From inspectors’ reports of inspections at nurseries where infected trees were found on site, following targeted surveillance since the first find, all deliveries pre date the first finding of Chalara.

January 2013