The story so far: the difference we’ve made in five years

It seems like yesterday I attended the first Observatree meeting in London and here we are, five years later.

Working with Observatree volunteers has been a crucial part of our work at the Tree Health Diagnostic and Advisory Service (THDAS) at Forest Research (FR). We have delivered training and webinars, provided materials for the resources and we are a point of contact to answer the volunteers’ questions. Our main objective, together with all the partners involved in the project, is to build a network of volunteers that will act as a tree health early warning system.

So, here we are; five years on. Which priority pests and diseases (P&D) did Observatree volunteers find during this time? What have we done with their data and how have they contributed to our understanding of P&Ds in the UK? I’m going to try to answer these questions.

One of our main concerns at the beginning of the project was that the THDAS would be inundated with enquiries from Observatree volunteers, but this concern was unfounded. Volunteer enquiries represent around 10% of the total number of enquiries annually received at THDAS. This is because the Observatree volunteers have only submitted reports to THDAS when priority P&Ds were found or suspected. Every one of the reports submitted is potentially very important, possibly leading to immediate action to minimise further P or D spread. All of the other survey work undertaken by the volunteers is reported to project staff at the Woodland Trust.

So, how many priority P&Ds have been detected by Observatree volunteers? Of the 21 priority P&Ds monitored by the project, 12 were reported as suspected and eight of them were confirmed. This included the detection of the second Oriental chestnut gall wasp (OCGW) outbreak in England, the most northerly finding of Oak processionary moth (OPM) and Acute oak decline (AOD).

Additionally, enthusiastic volunteer activity has led to the detection of Chalara on ash in nearly every single 10km-square in the Britain, and volunteers follow up other suspected tree health cases when we need more information or samples. For example, I asked volunteers to follow Dutch elm disease on Wych elm and to take pictures of affected trees. I also asked them to take samples of cedars because we needed to confirm that Sirococcus was the cause of the problem, and to collect negative data for specific diseases. I also know a volunteer who has developed his own system to detect specific diseases in the dark.

Such actions show the confidence and ability of many of our volunteers, who are capable of submitting reports on other tree health concerns beyond the priority P&Ds, as well as providing enough quality information to help us diagnosticians to identify the cause. It is through these interactions that the relationships become stronger and the network takes form.

All the priority P&D data submitted from Observatree volunteers comes directly to the THDAS at FR. These data are analysed every three months and an internal report is generated with all the enquiries received at THDAS (from Observatree volunteers and others). Since 2015, over 500 reports of suspected priority P&D have been submitted by Observatree volunteers. The main hosts reported have been ash, cedar, elm, horse chestnut, oak and sweet chestnut. The numbers of priority P&D reported were six in 2015, three in 2016 and six in 2017. During the first few months of 2018, four priority P&Ds were detected (Chalara, Sirococcus blight, OPM and OCGW).

While I’ve not yet had the chance to meet as many of our volunteers as I would like, I am very happy to be part of this valuable network and partnership. We are all still learning through the project and we’re always looking for different ways to make improvements. Communication is very important to ensure that we achieve our aims. I would like to say a big thank you to all of you for all the hard work. Let the momentum gained during the first five years continue, as the show must go on!