"I just need to check a few Ash trees". Why biosecurity is a social forestry issue

Young ash, November 2012, North Wales

A meeting of COBRA (the UK Civil Contingencies Committee) is hardly an event that would normally be associated with the world of plants or of forestry.  However, this week it happened.  Great Britain is apparently at war.  At war against a poorly understood pathogen (Chalara fraxinea) that causes the death of ash trees (Fraxinus excelsior) and is having a felt impact in other parts of Europe.  COBRA met to discuss the situation and plan a response.  Other than restating the case for the Plant Health Order banning ash tree imports, the COBRA meeting led on to the mobilisation of a Task Force, hundreds of volunteers, from government agencies, civil society organisations and within the forest businesses, to conduct a nationwide survey of ash trees, a rapid "look see" to try and identify and map the extent of any infection already present across the British countryside.

This "emergency survey" surely brings into sharp focus all the issues surrounding biosecurity and how far this is a social not an ecological or technical concern in either origin or response. All of these concerns apply to the other tree pest and disease outbreaks affecting Britain's trees at the moment too (red band needle blight in some pines, Phytophthora ramorum in larch trees, leaf miners and bleeding canker in horse chestnut trees). The important social dimensions that can be drawn out are as follows:

1. the economics of globalised trading systems have made the production and importation of plants from all over the world a practical proposition, and, most importantly, a cheaper or more reliable supply option than production and purchase of plants from national sources. Tree seeds may be collected in Britain (local provenance continues to be an important choice for consumers), but growing on seeds and achieving economies of scale and a cheaper end product is more often achieved in nurseries in the Netherlands and across Europe and even as far as China. Plant material can then go on to carry new pests and diseases from these countries through import back into the UK.

2. consumer demands for new exotic species and instant landscapes, means that gardeners and landscapers as well as sectors such as the cut flower market continue to press for new 'exciting' plants as well as large and semi-mature specimens, which drives expansion of the global horticultural trade.  This has extended the range of plant products being brought into the UK, with the associated suite of pests and pathogens which may not be considered, or if thought about, are usually very poorly known. 

A National Audit Office report (covering agricultural crops, as well as trees and shrubs) shows that the number of recorded outbreaks of pests and diseases has been rising from an average of 150 a year over the period 1993 to 2000, to more than 200 in 2001, with some 370 identified in 2002.  The rise in invasive pests and diseases tracks the rise in the value of plants and shrubs imported into the UK - increasing from £197 million in 2000 to £340 million by 2008. Research suggests that the movement of plants by the horticultural trade in the UK is responsible for 90% of all new pest and disease outbreaks. 

3. plant pests come in through routes which are not anticipated by scientists and decision makers because of sector-based approaches to biosecurity, for example the Asian longhorn beetle is thought to have entered the UK through cheap wooden packing cases used to transport ornamental stone products from China, very little to do with horticulture, and thereby slipping under the radar.  We need to think about making these connections in the biosecurity strategies and action plans.

Oak processionary moth

4. international and regional plant health governance and information systems provide barriers to control measures being put into pace and acted upon effectively.  To comply with the requirements of the World Trade Organisation,  import controls must have a scientific basis, otherwise they are considered as barriers to trade.  This means only scientifically named, known and described organisms can be controlled, but putting in place precautionary measures is not possible. Oak processionary moth is a good example of the issues, it took over 2 years for this organism to be listed as a specific threat and control species because the pest "was not expected" in the UK. Plant movements within the EU are more lenient.  The National Audit Office report also mentions that the information systems which could enable the measures which do exist to be acted upon are ineffective. It says "Inspectors do not have access to complete and timely information about imports to allow them to select those  hat are highest risk and inspect them on a timely basis.  Not all relevant inspectors have direct access to the dedicated link to HM Customs and Excise's CHIEF computer system, which records all imports arriving in this country, and have to rely instead on informal arrangements to find out about imports. None of the inspectors at Heathrow Airport and Felixstowe Dock retained the necessary information to demonstrate that the riskiest consignments had been inspected".  Even once identified within-country responses take time to prepare, the "competent authorities" follow scientific and consultation procedures which take time to complete before action is agreed between stakeholders.

5. the financial and political costs of enforcement and the development of scientific responses are not properly assessed, nor funded, and the costs are often perceived to be too high to take action.  Border control agencies as well as those with responsibility for enforcement in the forestry sector, e.g. FERA, DEFRA, Forestry Commission, have all experienced significant budget and staff reductions in recent years.  Science budgets have experienced the same, even though parts of the plant health and biosecurity portfolio have received continued funding.  None the less mobilising staff and resources to address problems requires those staff and resources to be in place at an adequate level for the size and scope of the challenge.  In addition, an effective process of prioritisation is required to ensure the limited resources which are available are focused on the most pertinent problems at both a national and regional or devolved level.  It is true to say that in many parts of the UK attention has not been on the progression  of Chalara because efforts have been focused on providing an effective response to Phytophthora in larch and redband needle blight in pines as these are important commercial forestry species, and, in some areas, make up a significant proportion of the tree cover in local landscapes.

Tree species coverage in high forest over GB - NFI data 1998

6. political and economic pressures and time scales do not allow for the potential benefits of non-action.  Human nature is to "do something", however, there is some debate about the benefits that could come from leaving nature to take its course.  With some species of tree which have a broad genetic base, and reproduce sexually, this might allow trees with some natural resistance to show themselves, providing stock for future propagation.  

7. humans might act as vectors moving pests and diseases through the countryside and greenspaces.  Wildlife corridors and the transmission of pest and diseases are considered as important issues in the tree biosecurity action plans.  However, very little attention has been focused on the interaction of humans along recreation and other "use corridors" and the movement of tree pathogens.  Restrictions on human movement in the countryside during the UK foot and mouth disease outbreak in 2001 was a major part of the response strategy, and similar restrictions and biosecurity measures have implemented as appropriate response in areas with Phytophthora although efforts were concentrated on contractors and forest workers rather more than members of the public.  Serious investigation of what, if any, contribution people make in the propagation of pests and pathogens should probably not be ignored.

Public Information poster - biosecurity action fit for the public?

8. public acceptance, information provision and social learning have not been considered as an important strand of biosecurity measures again until very recently.  This is probably a significant oversight.  Without public engagement in the biosecurity debate there is likely to be a continuing conflict between the public and the government and agencies' actions undertaken to halt the progress of pests and pathogens (closures of forest areas to the public where phytosanitary fellings are being undertaken, has already caused conflict with for example, mountain bikers and local tourism-based businesses in some parts of GB), and  less understanding and will for the public to take seriously measures they can put into place themselves to prevent further spread of disease.

9. cultural attachment and media attention can prompt action and change the balance of political costs, which is probably a truism, but always worth remembering that when a society calls for action politicians feel obligated to act.  Ash trees are important in the British landscape, they exists not only as forest trees, but are found as parkland trees, trees in hedgerows, trees on farmland, trees on the side of roads in along river and stream sides.  It is a species almost as ubiquitous as the oak.  The increased public interest in woods and forests in the last two years, combined with the knowledge that the impact of loss might be as "devastating as Dutch Elm disease" in terms of the visual impact on the countryside, and the acknowledgement of a culturally iconic species and important ash woodlands in beloved landscapes such as the Peak District and the lake District all move to raise public concern and develop media attention.   

Many British trees have strong cultural values.
The Ash is the tree of life and attachment to the universe
in Celtic and Norse mythology

10. volunteering, the Big Society and citizen science may offer support in finding solutions and framing responses to biosecurity issues.  However public engagement is always a sensitive topic, when should the public be told, and how, and for what reason?  Finding the balance between openness, avoiding mis-information, and avoiding panic reactions in difficult and controversial situations is always hard to judge.  Although much progress has been made on the public engagement and inclusion of the public in many other areas of forestry and woodland decision making, this has not been applied to engagement in biosecurity.  Many other lessons have been learnt by organisations such as the Woodland Trust, the British Trust for Ornithology (BTO), and the Sylva Foundation about citizen science and including the public in the monitoring of woodland related issues.  It is the BTO which handles the management of the citizen science bird surveys which inform the Woodland Bird indicators - a GB-wide biodiversity monitoring requirement.  The goodwill towards woodlands and forests, and the general public's interest in "being able to do something to help" should be harnessed, and may help to counter some of the impacts of a dwindling science and enforcement resource base.

The problem of Chalara in ash is not the end of the social story.  It is just the start.  Vigilance and action should be the watchwords of anybody with an interest in trees, woodlands, forests and the resilience of native woodland habitats in whatever country they live in.  New organisms are posing threats to British trees with ever increasing intensity.  In Britain anticipated threats discussed at the meeting of Tree Health Experts in July 2011 listed:

• 8-toothed Europe Spruce Bark Beetle
• Citrus Long-horn Beetle
• Asian Long-horn Beetle – maple and other broadleaves
• Pinewood Nematode – on pines
•  Pine Pitch Canker
• Brown Spot Needle Blight – on pines
• Spruce Budworm;
• Sweet Chestnut Gall
• Emerald Ash Borer
• Emerald Birch Borer
• Oak Wilt
• Plane Wilt – London planes very susceptible 

Without a proper consideration of the social mechanisms affecting biosecurity, the socially valued costs and benefits of pest and disease outbreaks, and new strategies for public engagement the outlook for many more tree species in Britain really does feel very bleak.  All of the understanding about the social dimensions of biosecurity should be a call to arms .... it is the social side of biosecurity which really needs to receive significant attention when looking for ways to ameliorate or change an increasingly worrying and growing environmental challenge.


MORE INFORMATION AND RESOURCES

Sign up to the Forestry Commission tree pest Twitter account

• https://twitter.com/treepestnews 

Key scientific facts from the Forestry Commission

• http://www.forestry.gov.uk/forestry/INFD-8ZSS7U
• http://www.trees.org.uk/aa/documents/amenitydocs/2012_documents/14_Webber-AA.ppt

Learn more about the signs of Chalara and the history of the organism's invasion here:

• Spotting Chalara - FERA
• Spotting Chalara - Forestry Commission
• Chalara - History and epidemiology

Use crowd sourcing apps to report Chalara and other tree diseases here:

• UEA's Ashtag
• Sylva Foundation TreeWatch  

Find out more about other tree disease and pest threats and responses here:

• Forestry Commission - tree health threats 
• DEFRA - tree health and biosecurity Action Plan
• Parliamentary POST notes on tree health

Listen to some interesting viewpoints here:

• BBC Radio 4, Material World

SCIENTIFIC ARTICLES

Fisher, M.  2012.  Emerging fungal threats to animal, plant and ecosystem health. MYCOSES.  55:79-80

Fisher MC, Henk DA, Briggs CJ, Brownstein JS, Madoff LC, McCraw SL, Gurr SJ. 2012. Emerging fungal threats to animal, plant and ecosystem health. Nature. 2012 Apr 12; 484(7393):186-94

Adam E. Kokotovich and Adam R. Zeilinger, 2011, Exploring social and institutional variation across oak wilt risk management programs in Minnesota, USA, Urban Forestry & Urban Greening, 10(1) : 39–45

Smith, R. M., Baker, R. H. A., Malumphy, C. P., Hockland, S., Hammon, R. P., Ostojá-

Starzewski, J. C. and Collins, D. W.  2007.  Recent non-native invertebrate plant pest 

establishments in Great Britain: origins, pathways, and trends. Agricultural and Forest 

Entomology, 9: 307–326. doi: 10.1111/j.1461-9563.2007.00349

Matthew J.W. Cock with inputs from Marc Kenis and Rüdiger Wittenberg, 2003.  Biosecurity and Forests: An Introduction with particular emphasis on forest pests.  http://www.fao.org/docrep/006/J1467E/J1467E00.htm#TopOfPage