Tree Health and Plant Biosecurity

Written evidence submitted by Dr David Lonsdale

I welcome the opportunity to respond to the questions below. I am a tree pathologist with 26 years of service at Forest Research (the research division of the Forestry Commission) until early retirement in 2002. I have therefore concentrated especially on the questions concerning the need to maintain a core of specialists with the skills needed in order to assess and manage risks from tree 'pests' and diseases. Now in semi-retirement, I believe that I can claim to have no current self-interest in arguing for improved research funding.

My responses to the Committee's questions are as follows.

1. Are the roles and responsibilities of public agencies for monitoring incidences of plant and tree diseases or pests sufficiently clearly defined

1.1 I am not well qualified to answer this question but my impression is that there is some overlap between the roles of Defra and the Forestry Commission in presenting information and advice to tree owner and to the public. Any such overlap is, however, not necessarily a problem, given the connectivity between the websites of the different government agencies. I have far greater concern about a related matter; i.e. the co-ordination between the agencies (see below).

2. Are the Defra, Forestry Commission and Food and Environment Research Agency (Fera) contingency plans for managing a disease outbreak, such as Chalara fraxinea, adequate and appropriate to control its spread and mitigate the impacts of disease?

2.1 Owing to a lack of personal involvement, I am again not well qualified to comment. As a bystander, I have an impression that the agencies have worked well in mobilising resources for the management of various alien 'pests' and pathogens now present in the UK. On the other hand, I am concerned that tree owners are not compensated for the compulsory destruction of affected trees. I appreciate that some importers might be accused of being risk-takers, albeit within the law. On the other hand, lack of compensation could discourage them from reporting suspected outbreaks to the authorities, quite apart from any question of 'natural justice'.

3. How effective is co-ordination between agencies such as Natural England, the Forestry Commission and Fera?

3.1 I will not comment on the tactical co-ordination between these agencies at times of emergency, of which I know little. I am, however, seriously concerned about the procedures for communicating specialist advice to decision makers (and to those who draft answers to Parliamentary Questions) in the relevant government departments. In my own experience, the lines of communication were too indirect and distant to facilitate a clear understanding of technical matters.

3.2 With specific regard to Chalara fraxinea, I understand that decision makers were being advised in 2009 and beyond that there was no need to ban the importation of potentially infected plants, since the fungus was already present in the UK. In reality, the native Chalara was not the same as the ‘look alike’ species that was ravaging continental populations of ash. Although proof of this vital difference had not been obtained at that stage, there was extremely strong circumstantial evidence that a new and aggressive pathogen of ash trees was spreading on an advancing front across the Continent.

3.3 Any competent tree pathologist would have recognised that our ash trees were threatened by a fungal "wolf in sheep's clothing". I can therefore only assume that advice was obtained from someone other than a pathologist, or that the right questions were not asked. In any case, there is a need to ask why pathologists should have to wait to be consulted before feeling free to communicate their concerns.

3.4 Also on the subject of expertise, I would be seriously concerned about any merging of responsibilities that would further diminish the influence of tree pathologists. Tree diseases pose various difficulties that are not likely to be apparent to specialists in other fields; even the pathology of herbaceous plants.

4. Are there sufficient resources for research to provide effective evidence on the emergence of new threats to trees and plants and for management of existing threats? Is there sufficient coordination of research effort and does the UK have an adequate pool of the right skills to draw upon?

4.1 Although it is difficult to judge what is "sufficient", I have a strong impression that current resources are woefully insufficient. In order to provide evidence of emerging threats and to be ready to manage them, we need a core of dedicated, well-motivated specialists. But despite a great increase in the overall level of risk (owing to increasing international trade in high-risk goods, coupled with climate change), we have seen a severe decline in the number of specialists in the universities and also some decline in the number of specialists at Forest Research. Some of the long-established specialists, who joined that organisation in the 1960s and 70s were replaced after retirement but their departure seems to have led to an overall loss of expertise.

4.2 The effectiveness of research organisations can be undermined in further ways by the need to operate internal markets. This can, for example, interfere with the provision of services between different units within an organisation.

4.3 Certain aspects of 'management culture' have in my experience also helped to undermine the core of expertise that the nation requires in the face of new threats to trees. Specialists require freedom to pursue lines of research that develop naturally from their previous and current work. It is also necessary to realise that not every aspect of tree disease research can pay its way in terms of timber value. The value of the research will often lie in the resulting knowledge and skills, which will be needed in order to assess and manage emerging threats. Such knowledge and skills could, in my experience, be readily gained at Forest Research many years ago. Later, new policies for funding led to a requirement to ensure that an identifiable 'customer' was paying for every aspect research, as identified on timesheets within an accuracy of 6 minutes per item.

4.4 Clearly, someone has to pay for research but core funding should be sufficient to maintain the expertise needed to address the serious risks that are posed by alien pests and pathogens. Also, the undeniable need to manage public funding prudently does not mean that accounting procedures should waste the time and emotional capacity of specialists, whose motivation and productivity stems from their zest for discovery; not from edicts handed down by senior managers.

4.5 As far as universities are concerned, their increased dependence on conditional funding seems to have inhibited the free exchange of ideas and information that can greatly assist the development of methods for assessing and managing risks from tree 'pests' and diseases. Co-operation that was once freely available is often unachievable except through unwieldy and contrived multi-institutional projects that have to be laboriously cobbled together in order to meet requirements for potential funding.

5. Are sufficient resources being put into developing effective responses to plant health threats, such as improving resistance, biocontrols and chemical or management responses?

5.1 This question is perhaps mainly relevant to pathogens that are already causing a problem in the UK. We should, however, also be ready to develop methods of control of other pathogens that might become established here in the future, perhaps through co-operation with colleagues overseas.

5.2 With regard to pathogens that have become established in the UK, such as various species of Phytophthora, I have seen very little evidence that sufficient resources are being provided for research. Unfortunately there can be no promise of success in the face of some of the most challenging pathogens but there is cause for hope if we can develop an adequate understanding of the interactions between the tree, the pathogen and the environment. This would involve "classic" pathological research of a kind that seems to take place very little in the UK nowadays. There is also a need for carefully targeted genome-based studies.

5.3 The development of resistant varieties is a very important strategy for the future, but many years of research could be required in order to establish a new generation of resistant saplings. Meanwhile, it is essential that genetic resources for a breeding programme, in the form of seeds and of other material for propagation (e.g. buds) are collected and maintained under storage. I am not aware of resources being made available for such work on any suitable scale.

6. Does the international regime for trade in plants and the EU plant health framework provide a sufficiently flexible and responsive framework to respond to newly identified pests and diseases or to those that are spreading? Can these regimes impede stronger import controls?

6.1 I suggest that the facts speak for themselves. Under the current system, we have seen an unprecedented number of very dangerous exotic pathogens occurring here in recent years, including several Phytophthora species, the Chestnut blight fungus (Cryphonectria parasitica) and Chalara fraxinea (although it is possible that the latter might have spread on the wind from the near continent, as well as via infected imports). Imported trees can harbour such pathogens in a virtually undetectable state until long after they have been planted out. The risks are clearly so high that there is justification for far more stringent controls than appear to be available under the current framework. There is therefore a need for a revised framework, which can enable us to defend our island status, whereby the natural barrier of the sea provides our trees with some degree of protection, provided that we do not unwisely allow infected trees to be imported.

7. Are plant health controls sufficiently broad to cover trade in tree and plant products such as biofuels?

7.1 I think almost certainly not. Trade in such products could remain as an Achilles Heel in our control measures, even if we can restrict trade in living plants. We need to assess the risks, using the best available expertise and to take action wherever the risks warrant the imposition of controls under whatever framework is currently in operation. In the case of low-value / high volume products such as biofuels, the risks would seem to be potentially high in relation to the value of the trade.

7.2 There is similar cause for concern about wooden packing materials, which can harbour exotic pests and pathogens, such as the so-called Asian longhorn beetle, which recently became established in Kentish woodland near a site where Chinese packing materials had been unloaded. Proper disposal of such materials should be required, given that inspection at ports of entry can probably never be sufficient to prevent the important of dangerous organisms by this means.

8. What lessons are being learnt in the UK from the management of Chalara dieback of ash in other EU Member States: for example on trade in plants, management of infected trees including saplings, and development of resistant trees?

8.1 The main lesson to be learnt about trade is that it spreads the fungus much farther and faster than would happen by the natural spread of spores.

8.2 A number of EU member states are testing trees derived from apparently resistant parents but not always with success. There has also been some work, for example in Sweden, on the rate of progression of disease in mature and veteran ash trees, which indicates that they can survive for at least several years. Pruning out infected parts of a tree might be helpful in theory but studies in Sweden indicate that it can do more harm than good, since the resulting loss of leaf area reduces the ability of the tree to produce sugars that are needed in its defence against other pathogens such as honey fungus.

January 2013