Trees: British Ash Tree

Lord King of Bridgwater Excerpts

Monday 5th November 2012 Lords Chamber

[Lord King of Bridgwater]

My Lords, an unexpected change in the business of the House has meant that in the quiet of the evening in your Lordships’ House we have had a debate of quite exceptional quality and of importance to our country. I congratulate most warmly my noble friend Lord Selborne on his excellent introduction to this debate. With regard to both the noble Lord, Lord Best, with his particular involvement in the Tree Council, and my noble friend Lord Framlingham with his expertise, the House has already produced a debate of exceptional quality and importance. If I exclude the noble Lord, Lord Clark, it is simply because, as chairman of the Forestry Commission, I was disappointed that he decided to refer exclusively to the present year when, among everybody looking at this, there is real concern in the country as to what has been going on for some years about identifying it. Nobody in this country can pretend that we are not aware of the problem of imported disease of one sort or another. We have lived through Dutch elm disease; we live with sudden oak death and the problems of the larch, the beech and the horse chestnut. We are familiar with these problems. There is real anger in this country that there has not been an earlier identification of this problem. I looked at this. If trees were dying in Poland in 1992; if the pathogen, the asexual fungus as it is referred to, was identified in 2006; if the sexual stage of the fungus was identified in 2010; and if the Horticultural Trade Association warned Hilary Benn of the scale of this problem in 2009, what has actually been going on?

Perhaps I should have done so at the start but, in the face of much greater knowledge that has already been expressed, I declare my interest. My family own some woods in which ash is the predominant species; the natural regeneration in those woods is ash. We view the present situation with enormous alarm. We got a letter from the Forestry Commission, sent out late in October to all wood owners, saying that it will treat the fungus as,

“‘quarantine’ plant pathogen, which means that we can take legally enforceable action to contain or eradicate the fungus when it is found. This is being done by using Statutory Plant Health Notices which we serve on site owners. The Notice requires the owner of the land to remove and destroy affected plants by burning or deep burial on site”.

Does that apply to all ash? Does that apply simply to seedlings? Does it apply to young saplings? What does it apply to? There is this sort of confusion and difficulty at the moment.

I say to my noble friend, in congratulating him upon his appointment to his new position, that he has arrived at an interesting and challenging time; “May you live in interesting times”, as one might say. I say to him that I do not blame the Government for the origins of this. I do not blame them for the failure to identify it much earlier, but they do now have a major challenge on their hands. The noble Lord, Lord Best, made that very clear. He said that there were 72 million ash trees in this country; that will be two or three times the scale of Dutch elm disease. This is an issue now of enormous concern in the countryside. I am absolutely convinced that it was right to debate it tonight. I understand entirely why my noble friend may not be able to answer all the questions that have been asked tonight, but I hope that he at least draws from this debate the sense of the enormous concern in the countryside and throughout the country. We see the Forestry Commission saying that people should wash their boots and watch where they go. Are we going to ban all access to woods? Are we going to ban bridle paths, footpaths and ruts, as they are called? What are we going to do?

Obviously, we will have on Wednesday a better picture of the scale of the spread of this fungus and the difficulties that it may pose. However, I do not think that anybody should underrate the challenge that the Government now face, and the importance of taking early action to address it.

--- Later in debate ---

[Lord Knight of Weymouth]

My Lords, the noble Earl, Lord Selborne, is to be congratulated on securing and introducing this important debate so effectively. As others have said, it has been a high-quality debate, even at this late hour. In among the shambles of the Government’s handling of business in this House, it is most welcome that we have time to debate the future of such an important feature of the British landscape.

As others have said, this is a subject that the public care deeply about. We saw that over the forest privatisation proposals and I have seen it in the last 24 hours on this issue. Yesterday morning I tweeted:

“I am speaking in tomorrow’s Lords debate on the future of the British ash tree. What questions do you want me to ask the minister?”.

I have been inundated with responses—the biggest reaction to a single tweet that I have ever had. Having discovered something close to crowd-sourced opposition and direct democracy even in the House of Lords, I will try to base my contribution on what the public have said to me in the last 24 hours.

Several wanted me to focus on action now and into the future. I will try to do this, but I would like first to put on record my understanding of the chronology of the disease in this country. In 2009, as has been said, the Horticultural Trades Association warned that we should have a ban. The Forestry Commission and Defra scientists reflected the latest international scientific opinion of the time that the disease was actually a mutant of a pathogen already endemic in Britain. However, in 2010 the science changed. Chalara fraxinea was identified then as a new pathogen, named Hymenoscyphus pseudoalbidus and, as late as autumn 2011, the Forestry Commission confirmed that Britain was clear of the pathogen. It was then discovered in imported saplings in February this year.

Many correspondents to me want to know why the Government did not ban imports at that point. Why did we have to wait until infection reached trees in the wild? Given that this disease has had such a catastrophic effect on ash trees in continental Europe, should we not have been more sensitive to the threat? Given that, as Defra’s chief plant health officer, Martin Ward, said today:

“Aerial spread does not happen until the summer”,

would it not have been wise to impose the ban at the start of the summer? As Tony Juniper asked me:

“Why were we importing ash trees when there are hundreds of millions in the UK already? Which other native trees are at similar risk?”.

The subject of other species takes us on to the capacity of the Forestry Commission to deal with this threat. The commission’s February 2011 staff consultation document on redundancy, following its 25% cut in funding, said, under high-level risks on page 24:

“There is no capacity to deal with costs of disease or other calamity. (e.g. Phytophthora is currently an unfunded pressure for 2011/12.) Mitigation: ensure full awareness of this loss of capacity”.

Forest Research, which is part of the Forestry Commission, is losing 60 out of a total of 222 staff over the CSR period: a cut of 28%. Thirty-eight of these staff have already gone. I would be interested to know how the Minister squares this with what his ministerial colleague, David Heath, said in the other place: that there had been no cut-back in resources applied to plant health and tree health in this country. The seriousness of this is reinforced in an interesting blog by Gabriel Hemery:

“During 2012 alone tree scientists at Forest Research have had to face an Asian longhorn beetle outbreak, sweet chestnut blight, and ash dieback. This is in addition to oak processionary moth, Phytophthora ramorum in Larch, and acute oak decline that were already big-enough problems to tackle”.

We have also, over the weekend, read of raised concerns that Scots pine is under threat from similar pathogens. Can the Minister give reassurance that not only is there sufficient protection for the scientific resource needed to work on Chalara fraxinea but that it will not be at the expense of our resilience to other disease outbreaks that could potentially arise? I suggest to him that if this is serious enough to convene COBRA last Friday—and it is—then it has the attention of the whole of Government. Now is the very best time to demand more resource from the Treasury to fund the research and monitoring that this crisis needs.

Most other questions relate to the science. Lithuania, where 99% of ash were lost to the disease, has had success in developing resistant strains of ash. Does the import ban apply to resistant strains of the species? Is the further destruction of ash trees in this country going to be sensitive enough, as others have said, to retain those trees displaying a resistance, given that there is considerable diversity in our ash stock? Are the Government instigating an intensive breeding programme of pathogen-resistant trees? Is there a role for genetic modification? What does the science tell us about the spread of the disease? If felled trees are burned, how do we prevent spores spreading through smoke plumes? If the disease has been carried across the North Sea on the wind or by birds, as the Government claim, will washing our boots—or, for that matter, our children—have any effect? If walkers’ biosecurity is a serious risk, will there be provision for the public to disinfect their footwear, as with the foot and mouth outbreak? Finally, would it be sensible, as the noble Lord, Lord King, mentioned, for forests with high numbers of ash trees to be closed to public access?

This is fast developing into a catastrophe for our natural environment. The ash tree is an iconic part of the British landscape and we should all be doing what we can to monitor the disease and follow scientific advice on how best to combat it. At a time when so many of our tree species are under threat, when we increase risk by importing so much horticulture, now is the time to value plant science, invest in urgent research, work with European partners and value expertise. I look forward to the Minister’s reassurance.

[Lord King of Bridgwater]

The noble Lord talked exclusively about the present year and the past year. Has he nothing to say about how it could be that a disease that is well established and was recognised in the continent of Europe some 15 years ago could not be identified, and why the precautionary principle that one would think would be important in these issues and the need to take action were not recognised? Will the noble Lord comment on that, because he is otherwise in danger of making what could have been a valuable contribution appear to be too much party-political?

[Lord Knight of Weymouth]

I am delighted to contribute, although I ran out of time some time ago and it is always amusing to be accused of being party-political by the noble Lord. However, I refer him to an article in the New Scientist, dated 31 October, by Andy Coghlan, in which he talks through the science. It is clear that the science changed in 2010. It is also clear that Ministers were not consulted by officials in 2009. That is something we can discuss at a later date. I am looking forward to the Minister’s reassurances.

[The Parliamentary Under-Secretary of State, Department for Environment, Food and Rural Affairs (Lord De Mauley)]

My Lords, I thank my noble friend Lord Selborne and all noble Lords for their extremely helpful contributions in this debate.

The ash is one of our most recognisable trees and we have about 80 million of them in our country. This debate focuses on the dangers to them posed by Chalara fraxinea, but of course it goes much wider. I must declare an interest as a grower of trees, including ash. The Government are taking the threat posed to the British ash tree extremely seriously. Let me start by setting out very clearly the current situation, our scientific understanding and the action we are taking. Ash dieback is a disease caused by a fungal pathogen that has devastated ash across northern Europe. With ash trees representing 5 per cent of Britain’s woodland cover, the potential impact of this disease on our landscape is significant.

I am going to try to avoid being party political, but before 2010, the scientific evidence in Europe indicated that the organism responsible for ash dieback disease was one that was already widespread and native in Great Britain. This precluded the use of import restrictions as a means of control. In 2010, new scientific evidence was published which correctly identified the pathogen that caused the disease. Between 2009 and 2012 the Forestry Commission inspected 15,000 individual ash trees across the country located in more than 8,000 groups. Of these, 103 trees were discovered to be in ill health. None of these was identified as caused by Chalara.

In February 2012, a routine nursery inspection discovered Chalara, and this finding was confirmed on 7 March. Immediately, the UK plant health authorities deployed additional resources to carry out trace-forward inspections of material known to have been supplied from the infected nurseries. Over the summer, 1,000 at-risk sites were identified and 100,000 saplings were destroyed. In parallel, the authorities developed a pest risk analysis, required, as noble Lords know, as the basis for intervention. Once completed, this analysis was fast-tracked into a shortened consultation to discover the extent of Chalara in Great Britain. During this time, the industry instituted a voluntary moratorium on imports of ash planting material, and I offer it my strong thanks.

On Friday 26 October, this consultation closed. From the early afternoon of Monday 29 October, the movement of ash from anywhere that is not a certified pest-free area—right now, nowhere has that label—became a criminal offence in time for the start of the main UK planting season at the end of November. During the consultation period, Chalara was confirmed in the wider environment in East Anglia. These trees had no apparent connection to nurseries and suggested the presence of Chalara in Great Britain for quite some time. It is possible that this infection was caused by spores blown by the wind from continental Europe, but further investigation is ongoing.

I turn now to the current situation. As my noble friend Lord Selborne said, this morning’s situation report confirmed Chalara in 14 nursery sites, 36 sites where ash has recently been planted and 32 sites in the wider environment. Over the weekend, we have confirmed that, in addition to the cases in the wider environment in East Anglia, there are also cases in Essex and Kent.

Our scientific understanding suggests that Chalara is not currently spreading. The period of spore release is normally the summer. In the winter, the main method of spreading the disease would be movements of ash material. This, as I have said, is now banned. As ash leaves fall to the ground, there exists a risk, although it is rated as low, of the spread of the disease through the long-distance movement of leaf litter on, for example, boots and tyres. In answer to my noble friend Lord King, we have no intention of unwarranted closure of woodlands to those who wish to enjoy them, but we ask woodland visitors to ensure that they take appropriate precautions when leaving woodland.

Our understanding of Chalara continues to develop. Last Thursday, Defra Chief Scientific Adviser Professor Ian Boyd convened a group of international experts to understand better the epidemiology of Chalara fraxinea. We are dealing with considerable biological uncertainty but we are determined to make the best use of the science available to tackle this pathogen.

[Lord King of Bridgwater]

I will perfectly understand if the Minister cannot answer this question now, or he may like to put a letter in the Library. He made an interesting point about why this was not identified earlier. In a sense, it was. Something that had killed 90% of the ash trees in Poland was thought to be a pathogen that was already widespread and established in this country. But we did not lose that number of trees at that time. How was it that something that killed all those trees in Poland could be thought to be widely established even if it did not kill any trees in this country?

[Lord De Mauley]

My Lords, I am not sure that I shall be able to answer my noble friend’s question entirely. I said that before 2010, the scientific evidence indicated that the organism responsible for Ash dieback disease was one that was already widespread and native in this country. But new scientific evidence was published in 2010 which correctly identified that that was not the pathogen and that a different pathogen caused the disease. I hope that that is helpful.

Professor Boyd concluded that: spores are mainly dispersed by wind during the summer; transportation of leaf litter should be avoided; Chalara will infect any form of ash, so exotic species in which Chalara is not pathogenic could act as vectors; latency from infection to overt disease is a matter of months; wood products would not spread the disease if they were treated appropriately using simple methods; trees probably need quite high doses of spores to be infected and may only become infected under specific conditions that are currently not understood; data from Norway suggest a spread rate of the infection front of 30 kilometres per year; once infected, ash trees cannot be treated; Chalara itself tends to kill only young trees; older trees are weakened and die from other causes and this can take years; there appears to be innate genetic resistance in some trees; and it appears that trees within forests tend to die most quickly because of secondary infection from, for example, honeydew fungus.

We are guided by the science. Our first priority is to establish the distribution of Chalara in Great Britain. This will inform our plan for tackling the pathogen. In this surveillance, we are determined to strike the right balance in the necessary trade-off between speed and thoroughness. There are two main surveillance operations under way. First, the Forestry Commission, whose staff have been working weekday and weekend, is undertaking a survey throughout Great Britain that will cover more than 2,000 10 kilometre by 10 kilometre squares in which sample trees will be examined. These survey areas are dispersed across the entire country, with an initial focus on East Anglia and the south-east, which are the areas at greatest risk of wind-borne infection from mainland Europe. To date, the Forestry Commission has inspected more than 1,000 of these squares, and we expect the survey to be substantially complete by the end of the week.

Secondly, the Food and Environment Research Agency is working hard to inspect sites that have been traced as receiving saplings from nurseries that have handled suspect consignments. In addition, we have asked a number of organisations, including the Country Land & Business Association, the Royal Forestry Society and the Royal Scottish Forestry Society, for their members’ help with surveillance over the next few days. I am enormously grateful for the positive way in which they have responded. This rapid surveillance will give us an indication of the extent of Chalara in Great Britain, equipping us to tackle the pathogen. On Wednesday, the Secretary of State and I will welcome industry representatives and stakeholders to a specially convened ash dieback summit. Ensuring that we are working with the science and with stakeholders is crucial to the effective management of the disease.

Noble Lords asked a number of questions. I will do my best to address them. The noble Lords, Lord Clark and Lord Judd, asked whether we could still burn ash firewood. We can. There is a very low risk of spreading the disease by moving firewood, but it will not be possible to move logs from affected areas in the United Kingdom where a notice has been served. One noble Lord asked whether burning trees would risk dissipating spores in the smoke. The indications are that that is very unlikely.

The noble Lord, Lord Clark, asked what the ban meant. All imports of ash-planting material are banned, as no pest-free areas exist in other countries. Movements of ash within the United Kingdom are banned pending full surveillance activity that will determine the pest-free zones.

Several noble Lords asked about Forestry Commission funding. While the Forestry Commission’s overall budget has decreased since 2010, it is not true to say that funding for plant health has decreased. The Forestry Commission’s budget for plant health research, which was £1.4 million in 2010-11, will be £2.1 million for 2014-15. Fera is responsible for plant health across the board. Its budget for plant health research was £667,000 in 2010-11 and will be £1.45 million in 2013-14. Defra has also allocated £1.3 million for each year of the current spending review period under the tree health action plan, and £800,000 for tree health research under the Living with Environmental Change programme for each year of the current spending review period. This funding will go one year beyond the current spending review period and will total £8 million over four years.

My noble friend Lady Parminter asked about the time taken for testing. In the lab, culturing an organism takes up to three weeks. Fera has adopted and developed a molecular method that reduces test time to less than four hours under ideal testing conditions. Following parallel trials of cultural and molecular tests, we are confident that the molecular procedure is robust, so it is currently our chosen diagnostic lab method.

My noble friend Lord King asked to what types of trees the Forestry Commission orders applied. Eradication action is required when the disease is found in nurseries or sites of recently planted ash. Containment notices are in place for those sites where the disease has been found in the wider environment pending the outcome of surveillance that is currently in progress.

The Government are taking further action in the full knowledge that Chalara will not, as some noble Lords mentioned, be the last pest to threaten our shores. Taking my noble friend Lord Selborne’s point, the Secretary of State has asked Professor Ian Boyd to convene a tree health and plant biosecurity expert task force to review our strategic approach to plant health as a whole, while at the European level, our negotiators are working to improve the pace of decision-making, the targeting of risk and the level of international co-operation within the EU plant health regime.

Furthermore, we are quickly bringing forward actions in our October 2011 tree health and plant biosecurity action plan—part of which, in answer to my noble friend Lady Parminter, importantly involves public engagement—to address the serious pests and pathogens not currently present in the UK.

I thank all noble Lords for their comments and suggestions, all of which I will take back. Chalara fraxinea is a serious threat to our ash population. We will continue to strive to understand and control it. We are also learning important lessons, which will help us combat future tree diseases.