Blog

Oak powdery mildew – what’s all the fuss?’, Elsa Field, Oxford University

It’s one of the most common pathogens on oaks in Europe and, in late summer (July-August), it’s hard to miss oak powdery mildew on the leaves of oak trees throughout the UK. You’ll notice a whitish “powder” coating the leaves, in some cases causing them to become highly distorted. This is the fungal mycelium, the asexual part of the fungus, which grows on living leaf tissue and hungrily taps into the sugars that the plant has busily captured during photosynthesis. There is no cure for oak powdery mildew, but nurseries routinely have to spray fungicides to prevent the pathogen from stunting the growth of young trees. This tree disease is a biotrophic pathogen meaning it can only grow on living tissue so doesn’t kill the host directly. However, it will reduce its growth by coating a large proportion of the tree’s powerhouses – its leaves – with mycelia, thus preventing […]

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‘Managing Sweet Chestnut Blight in the South West’, Emily Fensom, Forestry Commission England

The Forestry Commission England’s (FC) Tree Health team plays an important role in the protection of England’s trees, woods and forests. As a Tree Health Officer, I work with a range of colleagues from FC and our partner organisations to deliver a pro-active response to any reported outbreaks and the consistent day-to-day management of established pests and diseases. The Tree Health team carries out specialist surveillance for existing threats and monitors for emerging tree health concerns during the summer months when the tree crowns can be easily observed from the air. This year, we returned from the Christmas break to investigate the new finding of a high-priority disease, Cryphonectria parasitica, in Devon. Commonly known as sweet chestnut blight (SCB), this is a particularly nasty fungus which originates from Asia but is now widespread in continental Europe. Due to the quarantine nature of this disease, we needed to work out where […]

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David Griffith, Tree Health Surveyor, goes above and beyond for tree health

David Griffith has been volunteering as a Tree Health Surveyor with the Woodland Trust since the Observatree project started in 2014. Along with over 200 other volunteers involved in the project, David is tasked with surveying woods and trees for signs of pests and diseases including Chalara dieback of ash. Any positive sightings are reported to the Forestry Commission using the Tree Alert online reporting tool. The information submitted through Tree Alert is used to build up a picture of the distribution of pests and diseases across the UK, illustrated by maps such as the interactive Chalara map hosted by Defra. In recent months, David has been a man on a mission to fill in some of the blank squares on the Chalara map in West Wales where the disease hasn’t yet been reported. David has identified ash trees infected with Chalara dieback of ash in over 20 new 10km […]

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2017 training up-skills Observatree volunteers, Suzy Sancisi-Frey, Forest Research

Despite the best efforts of Storm Doris, Observatree year four volunteer training days ran smoothly over the course of February and March.  A big ‘thank you’ goes out to volunteers who braved the weather and managed to attend these sessions.  Eleven events were held throughout England, Scotland and Wales with one left to deliver in June for Northern Ireland. Once again the National Trust provided most venues for these events.  This meant we could enjoy the beautiful surroundings of properties such as Dunham Massey (NW England), Scotney Castle (SE England) and Tredegar House (Wales). Trainers came from Forest Research, Forestry Commission England and Scotland, APHA (Animal and Plant Health Agency), FERA Science Ltd and The Woodland Trust.  As with previous years, a range of topics covered: winter tree ID priority pests and diseases an outside survey activity a refresher demonstration on sampling and photography Looking at the feedback we’ve received […]

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‘Negative data is good!’, Jane Barbrook, APHA

One of the key messages we give Observatree volunteers is that you don’t have to find something to make a survey worthwhile or valuable. Developing a tree health early warning system network means that we are making an opportunity to spot something out of the ordinary. The flip side of this is that, on many occasions, a survey will result in not spotting a pest or disease of significance. True, when a new quarantine pest and disease is discovered it could avert a significant plant biosecurity impact. But this doesn’t mean that any other surveillance activity is less valuable. No news is good news as they say and so reported visits that declare nothing found are really important to us! Plant health biosecurity relies on collecting lots of different data. Proof of absence of a pest is required for: proving “pest freedom” maintaining our “protected zone” status for certain pests […]

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Simulating a longhorn beetle outbreak, Ellie Barham, Botanic Gardens Conservation International

On a spring day in May 2016, Charles Lane from Fera, his son, my partner and I headed up to the Yorkshire Arboretum near York to hammer nails into trees – all with the permission of the arboretum’s director of course! These nails (pictured) were to represent bore holes (typically 10mm in diameter) and would become part of a simulated longhorn beetle outbreak site based at the arboretum. Being able to recognise the signs of a damaging pest is only half the battle. The simulated outbreak site was designed to provide a training ground for volunteers, tree health professionals and the public. As well as offering an opportunity to practise surveying trees for inconspicuous signs, it also aims to emphasize the difficult nature of such surveys which, as participants discovered, is a challenge even when you know exactly what you are looking for. This simulation was modelled on a similar […]

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Observatree past and present, Peter Crow, Observatree Project Manager

Welcome to 2017. I hope you all had a pest and disease-free holiday As we now enter our fourth year of the project I thought it would be good to reflect on what a busy and successful year 2016 was for Observatree: In February we invited and were joined by an international audience at Kew to discuss tree health early warning systems in Europe and share our experiences During February and March Observatree volunteers attended annual training to further hone their survey skills. This was complimented by mentoring events in autumn. Volunteers made the most of this event by requesting specific activities to gain more practice and learn from professionals at hand March also saw a meeting with our project monitor who represents our funding body – LIFE. It’s great news that they continue to be impressed by the progress and impact of Observatree Over the year our Pest and […]

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Tree health early warning in the UK: a celebration of Observatree, Peter Crow, Observatree Project Manager

A dark November evening in London was brightened as many of those involved in the Observatree project gathered at the Houses of Parliament for a reception to celebrate what the project has achieved over the first three years and to help look towards its future. The project team and volunteers were joined by influential guests: MPs, peers, senior members of Defra plus representatives from the forestry, environment and charity sectors. Our event was sponsored by Chris Davies, MP for Brecon and Radnorshire and chair of the All-Party Parliamentary Group on Forestry. We thank him for his support. But this was not like a typical parliamentary reception. We did not want floral arrangements on tables. No. Our business is pests and diseases. We took along large wooden models of Asian longhorn, Emerald ash and Bronze birch borer beetles to adorn the historic setting. And they certainly generated interest as they went […]

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2016 Observatree mentoring events, Helen Jones, Observatree Engagement Officer

During September and October, the Observatree project delivered eight mentoring events across Scotland, England and Wales for their network of tree health surveyor volunteers. Led by tree health teams from the Forestry Commission and Natural Resources Wales the events enabled volunteers to see real examples of pests and diseases in the field, practice their observation skills and spend time with tree health experts and other volunteers in a woodland setting. Focusing on the priorities Each event focused on Observatree priority pests and diseases specific to the region. At Scotney Castle (Kent) volunteers were trained to spot oriental chestnut gall wasp and chestnut blight, seeing examples of Phytophthora cinnamomi and Amphiporthe fungus on sweet chestnut. Volunteers in the North East of England saw Phytophthora austrocedri on juniper along the Pennine Way, learning how the disease has spread through the site and that some of the juniper is still quite healthy. At […]

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‘Hunting for longhorn beetles and diseased trees’, Judith Garforth, Citizen Science Administrator, Woodland Trust

Citrus Longhorn - Plant Protection Service Archive, Plant Protection Service, Bugwood.org

Keeping your eyes peeled Observatree volunteers help to protect the UK’s trees, woods and forests from new pests and diseases by providing more eyes on the ground. The earlier tree pests and diseases are spotted and reported, the higher the chances that outbreaks can be eliminated or controlled.  At a recent Observatree volunteer mentoring event, I joined a group of volunteers taking part in a simulated longhorn beetle outbreak activity at the Yorkshire Arboretum. This had been set up by Charles Lane, Tree Health Scientist, Fera Science Ltd. Why longhorn beetles? The Observatree project focuses on a list of tree pest and diseases which are of the highest concern. Asian and citrus longhorn beetles are both Observatree priority pests that Observatree volunteers have been trained to identify and report. So far there haven’t been any known outbreaks of citrus longhorn beetle in the UK.  However the beetles have been intercepted […]

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