Forster, B.; Knizek, M.; Grodzki, W. (eds.) 1999: Methodology of Forest Insect and Disease Survey in Central Europe.
Proceedings ofthe Second Workshop ofthe IUFRO WP 7.03.10, April20-23, 1999, Sion-Chateauneuf, Switzerland.
Birmensdorf, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) 168-17 4.
DISEASE DIAGNOSTIC & ADVISORY SERVICE IN THE UK
David R Rose, Pathology Branch, Forest Research, Alice Halt Lodge, Wrecclesham, FARNHAM, Surrey GU10 4LH ,UK
This service was established in 1962 by the Forestry Commission as a stand-alone service to take pressure off researchers who were dealing with ever-increasing numbers of inquiries.
Though it had not been clearly stated before this time, there was a desire to note the diseases and disorders occurring during any year. However without any clear plan this ad-hoc
approach was clearly unsatisfactory. The setting up ofthe service in 1962 gave an opportunity to define the scope and aims on a more formal basis.
Scope
+Trees in:
• Forests & Woods .Farmland
• Public amenity areas
• Private amenity areas
The aim was, from the outset to cover trees wherever they occurred. A potentially serious disease was not going to differentiate between trees in gardens and parks and those in woods and forests. It was, however, decided to group them as shown above. Not only was this sensible when it came to analyzing the data but it also identified groups that might have to be dropped should resources prove limited. One group that stands out clearly in this respect is Private Amenity. Though it would be unfortunate if these had to be excluded it would be perhaps more acceptable than any of the other groups.
Customer Requirements
• To give impartial, accurate and effective diagnosis and advice on tree diseases and disorders in the UK
• To provide information on the general state ofhealth of trees in the UK
• To detect new diseases and changes in patterns of existing diseases
The remit was set out early on and aimed to achieve high standards in operation. However it was always recognized that, if a service was to be offered, the primary role must be to gather information on tree diseases and disorders. It was never regarded as a commercial venture as such an activity would not be compatible with the location of the service in a Research organization. Commercialization would inevitably result in the screening out of interesting, but uneconomic, inquiries. In time the service would handle a preponderance of insurance work, litigation cases and tree health assessment surveys on development sites. It might also prove difficult to be seen as a completely impartial service if it was run on strictly profit earning basis.
Organization
• The team at Alice Holt near Farnham in Surrey covers the UK south of the Humber/Mersey line
• The team at the Northern Research Station near Edinburgh covers 'the rest of the UK The entire country was initially covered from Alice Halt but in 1967, with the opening of the Northern Research near Edinburgh, two teams were established. The country was divided between the two stations with, as a result, NRS dealing mostly with upland forests and Alice Holt covering lowland forests. However, with the inclusion of Wales in its area, Alice Halt also covered some upland areas. Workloads differed markedly between the two teams with two or three times the number of inquiries being handled at Alice Holt. This was due to the greater range of woodland types and much higher levels of amenity trees in the Alice Holt area.
Staffing
Northern Research Station: Alice Holt Lodge:
• 2 Diagnosticians for 30% of their time • 1 Diagnostician for 80% of their time
• 1 Technician for 40% of their time • 1 Technician for 60% of their time
In 1962 the service was run by one Forest Officer working from Alice Holt spending nearly 1 00% of their time on this work. As the work load increased the time commitment increased accordingly and a second Forest Officer was then taken on. When NRS opened in 1967 the service was operated by two scientists for a proportion of their time with input from a
technician and this has largely continued to the present day. However Alice Halt continued to operate a fully staffed service with two Forest Officers and in 1975 added a Technician to the team bringing the staffing level to 3 man-years. A review of the Alice Holt service in 1989, when inquiries were running at over 800 per annum, showed that current staff levels were finding it difficult to cope. With no possibility of any increase in staffing, workload was to be cut by excluding inquiries relating to privately owned amenity trees. The reduction achieved was greater than that required to bring the workload into balance so it allowed staffing commitment to be halved at Alice Holt, freeing up time for the diagnosticians to undertake other project work. When charging was introduced in 1992, privately owned amenity tree inquiries were reinstated as it was realized that numbers would not return to their previously high levels. Current annual levels of inquiries are 100 at NRS and 500 at Alice Holt.
Promoting the Service
• The Service is publicized within the Forestry Commission but not outside
• Private Woodland owners are directed to the service by local Forestry Commission offices
• Other clients find the service by inquiry to Forest Research or by recommendation
Because staff levels are restricted the service is not generally advertised. It is well publicized within the forest industry and to a lesser extent amongst local authorities and other public
bodies. However no direct publicity has been aimed at the general public. This is unfortunate in some ways as only those who have heard of it through recommendation, or by determination to obtain an answer to their problem, will get through. It is impossible to say what useful and valuable information may be lost to us by adopting this policy. However, in these days of financial stringency, we can only operate where we have a customer who will fund the work.
The charges that would be needed to cover the full costs of the service would be too high for many ofthese inquirers and, as stated earlier, a fully commercial service based on individual full-cost recovery would be inappropriate in a government research organization. It would be good to think that the Forestry Commission would, or could, be able to increase funding in the future to allow it to expand and thus be able to advertise its services.
Operation
• Standardized Report Form is used to gather information
• Most diagnoses achieved from supplied information and samples
• Culturing and site visits used in the more difficult or important cases
The service is run using a database which provides day to day management as well as an archival facility. A key factor in this system is a streamlined inquiry handling procedure which has, at its core, a standard Report Form for gathering information. With information on this form and well-chosen samples it is usually possible to make an appropriate diagnosis within two to three days. As not everything in this life is perfect we may well have to consult the inquirer to clarify some points, request better specimens (the most common reason for contacting a client!) or even ask just what it is that is of concern.
Follow-up work, such as culturing and a site visit, can add to the time it takes to deal with an inquiry and is often unavoidable in certain cases. We are fortunate in being able to offer site visits but as these can be expensive we seek to reduce expenditure. This is mainly achieved by organizing visits into groups or tours aiming to cover three or four visits per day. In a few cases clients are willing to pay for an immediate visit or for a full day, or days, on site.
Detection of New Diseases or Pattern Changes
• Shoot dieback of Pinus contorta
• Phytophthora killing of Alnus species
• Phytophthora illicis on flex species
• Decline of Quercus robur
The test of any system is - does it work? Well, we feel it does. The DDAS has had success in detecting both new diseases and changes in patterns of existing problems. The ones listed above illustrate these types of cases very well. The first two are new diseases never before recorded worldwide though the Phytophthora on Alnus has now been found in several other European countries. The third was only known from North America until it was found in the UK as a result of a diagnostic inquiry. Since then there have been several cases each winter and from our contacts with other diagnosticians we know that it is now present in The Netherlands and Belgium. The fourth item is the emergence of a complex decline which was
probably last seen in the UK in the mid 1920's. All ofthese were picked up as normal inquiries reported to the service.
Special Investigations
• Detailed investigation of specific problems encountered
• Bronzing of Taxus baccata foliage
• Needle browning and dieback of Picea abies
• Decline of Quercus robur
• Specially commissioned consultancy work
As new or unusual diseases are picked up there may be a need to undertake more detailed investigation which fall short of being full projects. They are best dealt with under the control ofthe DDAS but some do eventually go on to become full projects in their own right. The following brief notes illustrate some of the special investigations we have undertaken in recent years and include one that has now achieved full project status.
The bronzing of Taxus baccata needles was a widespread phenomenon in 1994 and there was some concern that it might represent a new disease or an attack of Phytophthora. Indeed some growers had already destroyed trees on this assumption. Through detailed investigation it was clear that it was a physiological reaction to external stress and the condition was reversible.
Needle browning leading to dieback and death of Picea abies was widespread in central and eastern England in the early 1990s. Some cases resembled a condition known as "Top Dying"
in the UK or "Spruce Reddening" in other parts ofNorthern Europe. But that was clearly not the whole story. It was subsequently shown that the series of droughts years since 1975/1976 had been particularly severe in these areas. So much so that the commercial growing ofPicea abies over most of Eastern England has now been abandoned in favour of more tolerant spectes.
Decline of Quercus robur in southern England (as mentioned under "Detection of New Diseases or Pattern Changes" above) was first recorded in 1989 and became progressively worse. While not all plantations in the area were affected it was particularly severe where it did occur and would affect trees between 40 and 120 years old. Initial studies showed that, like the Picea abies, drought was the primary influence though this was insufficient in itself to account for the scale of the damage. As more work was undertaken it was clear that this was a complex decline and that similar declines were being recorded in other parts ofEurope. This problem has become a major project, parts of which are now EU supported in a Shared Cost programme.
As well as these we may be asked to carry out some detailed work for a client on a consultancy basis. Such work would not normally be chosen by us as an investigation but is something we can deal with because of our particular expertise. Recent examples were the investigation, using infra-red aerial photography, of poor growth of Picea sitchensis in Wales and the investigation of the deaths oflarge numbers of Platanus xhispanica in London Docklands.
Cost Analysis
• The service is fully funded by the Forestry Commission
• Individual clients pay a small contribution towards the cost of the service
• In total this contribution is around 15% of costs
• Consultancy work is fully funded by clients
The financing of the DDAS has already been alluded to earlier. The fundamental basis is that the Forestry Commission fully funds the service at the staffing levels already mentioned together with ancillary costs. They are thus the primary client for all our work. Our other clients, those with the tree problems, make a contribution towards the cost ofthe service by charges for various aspects of the work. Basic inquiry work is charged at a highly subsidized rate but additional work such as culturing and site visits are charged at full economic rates.
Taken all together the income earned, both cash and notional, amounts to 15% of the running costs of the service.
Consultancy work, as mentioned earlier, is fully funded by the client. Such work tends to be infrequent, probably only once every three years.
Key Benefits
• Intelligence on tree diseases in the UK is collected continuously for a relatively low cost
• The Forestry Commission receives a high level of recognition from the public for this work
• The work ofthe service underpins other research projects and provides a means of maintaining expertise
The benefits above are the reasons the Forestry Commission (and hence the Goyernment) funds the service. While the need for these benefits remains high then funding will remain assured, though they must be obtained by the most cost-effective means. At times this seems to mean with the few est staff and running close to, or exceeding, our operating limits.
Second to the role of intelligence gathering we would place the underpinning of the work of the pathology department. It is difficult, if not impossible, to be able to predicate in all cases the diseases of the future. The experience available through the DDAS is invaluable for meeting future problems and getting new projects off the ground.
Key Weaknesses
• Operates close to maximum capacity with the risk that some categories of inquiry might be excluded
• There may be a built-in latent period before an obscure disease is detected
The service, as has been said, is close to its capacity even without seeking to encourage inquiries. When the system is in danger of overload the only solution is the exclusion of some categories of inquiry, as with private amenity cases some years before. This would remove a very important source of intelligence on tree diseases in the UK.
Even with good coverage we are dependent on the observations of non-pathologists. By the time they notice something is wrong, a disease may be well-established. This would be particularly true of a disease that produced obscure or slow developing symptoms.
Monitoring Schemes
+The Forest Condition Survey provides some means of regular observation of a few major forest species
+ There is also an Amenity Tree Health Monitoring Scheme which uses over 100 plots in England to observe the health of public amenity trees
These weaknesses are overcome, to a great extent, by two monitoring schemes administered by Forest Research. The first, the Forest Condition Survey, has been running since 1985 and is a pan-European survey. Though it was originally set up to monitor the effects of pollution on forests it can provide information on other disorders and diseases. It only covers seven (six in UK) major forest species and is thus limited in the information it can provide in terms of diseases.
The second, the Amenity Tree Health Monitoring Scheme covering non-woodland trees, is funded by the Department ofEnvironment, Transport and Regions (DETR) and has been running in the UK since 1993. A network of just over 100 plots have been established throughout England (the DETR remit extends only to England) which have been selected to represent a range of site types- urban, parkland and rural. The scheme uses voluntary observers who visit the plots in June and early September each year to record any problems.
The plots contain a range of genera from 10 in the least varied plot to over 30. Some DDAS input is needed each year to follow up reports of damage or disease to obtain an accurate diagnosis.
The Future
+ Possible increase in disease problems due to climate change
• Anticipation of problems rather than simply responding to events
+Better integration with Plant Pathologists in the UK and the rest ofEurope
Much is being said these days about changes in tree diseases that may be brought about by climate change. There are certain clearly defined routes by which these changes can occur.
Knowledge of these and the pathogens that may take these routes can help in anticipating problems. This may then allow us to break free from our usual position of simply responding to events. When the increasing movement of plant material around the world is added into the equation the need to anticipate events is crucial.
Movement of hosts
Movement of pathogens
Climate change and new Diseases
Alteration of pathogen
Alteration of host resistance
In the UK a Phytodiagnosticians' Working Group has been in existence for the last three years.
It is a forum for diagnosticians to exchange information on techniques and new diseases, and to update knowledge on particular disease groups. A similar forum exists for mainland Europe instigated by the Dutch Plant Protection Service. A key element of Working Groups is the informality which helps to ensure that information passes quickly and freely.
Meetings such as this one, under the auspices ofiUFRO, offer a more formal means of cooperation. These meetings bring into play the policies of the official bodies that support the monitoring of pests and diseases more directly than the informal Working Groups. This combination ofthe informal and formal cooperative Working Groups will assist us in meeting the objectives of an effective diagnostic and advisory service and also in anticipating disease changes.
